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Document and Entity Information	6 Months Ended
Document and Entity Information	Jun. 30, 2015
Document And Entity Information [Abstract]
Document Type	S-1
Amendment Flag	false
Document Period End Date	Jun. 30, 2015
Entity Registrant Name	Kura Oncology, Inc.
Entity Central Index Key	0001422143
Entity Filer Category	Smaller Reporting Company

Condensed Balance Sheets - USD ($) $ in Thousands	Jun. 30, 2015	Dec. 31, 2014
Current assets:
Cash and cash equivalents	$ 19,788	$ 1,124
Short-term investments	26,145
Accounts receivable, related party	372	30
Prepaid expenses and other current assets	884	42
Total current assets	47,189	1,196
Property and equipment, net	59	27
Other long-term assets	279	150
Other long-term assets, related party	5	5
Total assets	47,532	1,378
Current liabilities:
Accounts payable and accrued expenses	2,492	846
Accounts payable and accrued expenses		833
Accounts payable and accrued expenses, related party	1,112	134
Convertible notes payable, related party, current		2,036
Other current liabilities		13
Total current liabilities	3,604	3,016
Convertible notes payable, related party		493
Other long-term liabilities	604	1,295
Other long-term liabilities, related party		7
Total liabilities	4,208	4,811
Commitments and contingencies
Stockholders' equity (deficit):
Preferred stock
Common stock	1
Additional paid-in capital	57,069	238
Accumulated comprehensive loss	(14)
Accumulated deficit	(13,732)	(3,671)
Total stockholders' equity (deficit)	43,324	(3,433)
Total liabilities and stockholders' equity (deficit)	$ 47,532	$ 1,378

Condensed Balance Sheets (Parenthetical) - $ / shares	Jun. 30, 2015	Dec. 31, 2014
Statement of Financial Position [Abstract]
Preferred stock, par value	$ 0.0001	$ 0.0001
Preferred stock, shares authorized	10,000,000	10,000,000
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Common stock, par value	$ 0.0001	$ 0.0001
Common stock, shares authorized	200,000,000	100,000,000
Common stock, shares issued	14,508,177	4,944,000
Common stock, shares outstanding	10,609,000	411,000
Number of shares, subject to repurchase	3,899,000	4,533,000

Condensed Statements of Operations and Comprehensive Loss - USD ($) shares in Thousands, $ in Thousands	3 Months Ended	4 Months Ended	6 Months Ended
	Jun. 30, 2015	Dec. 31, 2014	Jun. 30, 2015
Operating Expenses:
Research and development	$ 3,345	$ 2,028	$ 5,949
Research and development, related party	1,056	624	2,080
General and administrative	1,492	1,262	2,529
General and administrative, related party	14	20	37
Total operating expenses	5,907	3,934	10,595
Other income (expense):
Management fee income, related party	300	300	600
Interest income	22		22
Interest expense			(42)
Interest expense, related party		(37)	(46)
Total other income	322	263	534
Net loss and comprehensive loss	$ (5,585)	$ (3,671)	$ (10,061)
Net loss per share, basic and diluted	$ (0.54)	$ (25.98)	$ (1.47)
Weighted average number of shares used in computing net loss per share, basic and diluted	10,420	141	6,822
Comprehensive Loss:
Net loss	$ (5,585)	$ (3,671)	$ (10,061)
Unrealized loss on marketable securities	(14)		(14)
Comprehensive loss	$ (5,599)		$ (10,075)

Statements of Stockholders' Equity (Deficit) - 6 months ended Jun. 30, 2015 - USD ($) shares in Thousands, $ in Thousands	Total	Common Stock	Additional Paid-in Capital [Member]	Retained Earnings [Member]
Beginning balance at Dec. 31, 2014	$ (3,433)		$ 238	$ (3,671)
Beginning balance (in shares) at Dec. 31, 2014		411
Net loss and comprehensive loss	(10,061)
Ending balance at Jun. 30, 2015	$ 43,324

- Definition

The portion of profit or loss for the period, net of income taxes, which is attributable to the parent.

+ References + Details

Condensed Statement of Cash Flows - USD ($)
$ in Thousands

4 Months Ended

6 Months Ended

Dec. 31, 2014

Jun. 30, 2015

Operating Activities

Net loss

$ (3,671)

$ (10,061)

Adjustments to reconcile net loss to net cash used in operating activities:

Share-based compensation expense

237

1,129

Issuance of convertible note for acquisition of license

500

Change in value of derivative liability

^[1]

307

^[2]

Non-cash accrued interest expense

Non-cash accrued interest expense, related parties

Depreciation expense

Amortization of discount on marketable securities

Changes in operating assets and liabilities:

Accounts receivable, related party

(30)

(342)

Prepaid expenses and other current assets

(42)

(778)

Other long-term assets

(150)

(129)

Accounts payable and accrued expenses

833

1,382

Accounts payable and accrued expenses, related party

978

Other long-term liabilities

(998)

Other long-term assets, related party

(5)

Accounts payable, related party

135

Accrued interest, related party

Other liabilities

1,307

Net cash used in operating activities

(849)

(7,890)

Investing activities

Purchases of marketable securities

(26,260)

Purchases of property and equipment

(28)

(27)

Net cash used in investing activities

(28)

(26,287)

Financing Activities

Proceeds from issuance of common stock, net

47,841

Proceeds from issuance of convertible notes payable

5,000

Net cash provided by financing activities

2,001

52,841

Proceeds from issuance of related party convertible notes

2,000

Proceeds from the issuance of restricted stock awards

Net increase (decrease) in cash and cash equivalents

1,124

18,664

Cash and cash equivalents at beginning of period

1,124

Cash and cash equivalents at end of period

$ 1,124

19,788

Supplemental disclosure of non-cash financing activities:

Conversion of convertible notes and related accrued interest to common stock

4,327

Conversion of convertible notes and related accrued interest to common stock, related party

3,288

Financing costs included in accounts payable and accrued expenses

$ 253

[1]	The license agreement was executed in November 2014 and no change in the valuation occurred between the execution date and December 31, 2014.
[2]	The amount is included within research and development expenses on our condensed statement of operations and comprehensive loss. The change in fair value of the derivative liability for the three and six months ended June 30, 2015 was $210,000 and $307,000, respectively.

Organization and Basis of Presentation	12 Months Ended
Organization and Basis of Presentation	Dec. 31, 2014
Accounting Policies [Abstract]
Organization and Basis of Presentation	1. Organization and Basis of Presentation Kura Oncology, Inc. (the “Company”), a privately held company incorporated in Delaware, is a clinical stage biopharmaceutical company discovering and developing personalized therapeutics for the treatment of solid tumors and blood cancers. The Company focuses on the development of small molecule product candidates that target cell signaling pathways that are important to driving the progression of certain cancers. The Company aims to employ molecular diagnostics to identify patients with cancers who are likely to benefit from our targeted product candidates. From August 22, 2014 (inception) through December 31, 2014, the Company has devoted substantially all of its efforts to research, product development, raising capital, and building infrastructure. The Company has a limited operating history and the sales and income potential of the Company’s business and market are unproven. The Company has experienced net losses and negative cash flows from operating activities, and had an accumulated deficit of $3.7 million as of December 31, 2014. The Company expects to continue to incur net losses into the foreseeable future. Successful transition to attaining profitable operations is dependent upon achieving a level of revenues adequate to support the Company’s cost structure. The Company plans to continue to fund its losses from operations and capital funding needs through future debt and equity financing or through collaborations or partnerships with other companies. If the Company is not able to secure adequate additional funding, the Company may be forced to make reductions in spending, liquidate assets where possible, or suspend or curtail planned programs. Any of these actions could materially harm the Company’s business, results of operations and future prospects. The Company believes that its existing cash resources will be sufficient to fund its operations through at least December 31, 2015.

Summary of Significant Accounting Policies

6 Months Ended

12 Months Ended

Jun. 30, 2015

Dec. 31, 2014

Accounting Policies [Abstract]

Summary of Significant Accounting Policies

3. Summary of Significant Accounting Policies

Cash and Cash Equivalents

Cash equivalents consist of highly liquid investments that are readily convertible to cash and that mature within three months or less from the date of purchase. The carrying amounts approximate fair value due to the short maturities of these instruments. Cash and cash equivalents consist primarily of cash in readily available checking and money market accounts.

Short-Term Investments

Short-term investments are marketable securities with maturities greater than three months from date of purchase that are specifically identified to fund current operations. Short-term investments are classified as available-for-sale at fair value as determined by prices for identical or similar securities at the balance sheet date. These investments are classified as current assets, even though the stated maturity date may be one year or more beyond the current balance sheet date, which reflects management’s intention to use the proceeds from sales of these securities to fund our operations, as necessary. The cost of short-term investments is adjusted for amortization of premiums or accretion of discounts to maturity, and such amortization or accretion is included in interest income. The available-for-sale investments are carried at fair value with unrealized gains and losses recorded in other comprehensive loss and included as a separate component of stockholders’ equity (deficit). Realized gains and losses from the sale of available-for-sale securities and declines in value judged to be other than temporary on short-term investments, if any, are determined on a specific identification basis and are reclassified out of comprehensive loss and included in interest income in the condensed statement of operations and comprehensive loss.

Fair Value Measurements

Fair value is defined as the exit price, representing the amount that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants. As such, fair value is a market-based measurement that should be determined based on assumptions that market participants would use in pricing an asset or liability. As a basis for considering such assumptions, the guidance establishes a three-tier fair value hierarchy, which prioritizes the inputs used in measuring fair value as follows:

•

Level 1 — Quoted prices (unadjusted) in active markets for identical assets or liabilities;

•

Level 2 — Inputs other than quoted prices included within Level 1 that are either directly or indirectly observable; and

•

Level 3 — Unobservable inputs in which little or no market activity exists, therefore requiring an entity to develop its own assumptions about the assumptions that market participants would use in pricing.

Research and Development Expenses

Research and development expenses consist of salaries, benefits, and other personnel costs, preclinical and clinical trial costs, manufacturing costs for non-commercial products, and research and development facilities costs. All such costs are charged to research and development expense as incurred when these expenditures have no alternative future uses. Payments that we make in connection with in-licensed technology for a particular research and development project that have no alternative future uses (in other research and development projects or otherwise) and therefore no separate economic values are expensed as research and development costs at the time such costs are incurred. As of June 30, 2015, we have no in-licensed technologies that have alternative future uses in research and development projects or otherwise.

Clinical Trial Costs and Accruals

A significant portion of our clinical trial costs relate to contracts with contract research organizations, or CROs. The financial terms of our CRO contracts may result in payment flows that do not match the periods over which materials or services are provided to us under such contracts. Our objective is to reflect the appropriate clinical trial expenses in our condensed financial statements by matching those expenses with the period in which services and efforts are expended. As part of the process of preparing our condensed financial statements, we rely on cost information provided by our CROs (concerning monthly expenses as well as reimbursement for pass through costs). We are also required to estimate certain of our expenses resulting from our obligations under our CRO contracts. Accordingly, our clinical trial accrual is dependent upon the timely and accurate reporting of CROs and other third-party vendors. If the contracted amounts are modified (for instance, as a result of changes in the clinical trial protocol or scope of work to be performed), we modify our accruals accordingly on a prospective basis. Revisions in the scope of a contract are charged to expense in the period in which the facts that give rise to the revision become reasonably certain. Historically, we have had no material changes in clinical trial expense that had a material impact on our results of operations or financial position.

Share-Based Payments

Our share-based awards are measured at fair value on the date of grant based upon the estimated fair value of common stock. The fair value of awards expected to vest are recognized and amortized on a straight-line basis over the requisite service period of the award less estimated forfeitures. The fair value of each stock option is estimated on the date of grant using the Black-Scholes option pricing model that requires the use of subjective assumptions including volatility, expected term, risk-free rate, and the fair value of the underlying common stock.

Awards granted to non-employees are subject to periodic revaluation over their vesting terms. The fair value of non-employee awards is remeasured at each reporting period as the underlying awards vest unless the instruments are fully vested, immediately exercisable and nonforfeitable on the date of grant. We record the expense for stock option grants to non-employees based on the estimated fair value of the stock options using the Black-Scholes option pricing model. Estimated fair value of the restricted stock awards granted to non-employees is recorded on the earlier of the performance commitment date or the date the services required are completed and are remeasured at fair value during the service period. As non-employee restricted stock awards vest, they are remeasured at fair value and expensed based on the intrinsic value method which is measured as the difference between the exercise price paid for the restricted stock award and the fair value of the shares as the right of the repurchase lapses each vesting period.

Comprehensive Loss

Comprehensive loss is defined as the change in equity during the period from transactions and other events and non-owner sources, including unrealized losses on marketable securities.

Segment Reporting

We operate in a single industry segment which is the discovery and development of personalized therapeutics for the treatment of solid tumors and blood cancers. Our chief operating decision-maker reviews the operating results on an aggregate basis and manages the operations as a single operating segment.

Net Loss per Share

We calculated basic net loss per common share by dividing the net loss by the weighted-average number of common shares outstanding for the period, without consideration for common stock equivalents. Diluted net loss per share is calculated by dividing the net loss by the weighted-average number of common share equivalents outstanding for the period determined using the treasury-stock method. Dilutive common stock equivalents are comprised of unvested restricted stock awards and outstanding stock options under our equity plan. For all periods presented, there is no difference in the number of shares used to calculate basic and diluted shares outstanding due to the antidilutive effect of the securities. Because of our net loss, unvested stock awards representing an aggregate of 3,899,285 shares of common stock and options to purchase an aggregate of 410,000 shares of common stock, are excluded from the calculation of diluted net loss per common share as of June 30, 2015 due to the anti-dilutive effect of the securities.

Recent Accounting Pronouncements

In May 2014, the Financial Accounting Standards Board, or FASB, issued Accounting Standard Update, or ASU, 2014-09, Revenue from Contracts with Customers (Topic 606), that supersedes most current revenue recognition guidance, including industry-specific guidance. The guidance provides that an entity recognize revenue when it transfers promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services. This guidance also requires additional disclosure about the nature, amount, timing and uncertainty of revenue and cash flows arising from customer contracts, including significant judgments and changes in judgments, and assets recognized from costs incurred to obtain or fulfill a contract. The new standard allows for two methods of adoption: (a) full retrospective adoption, meaning the standard is applied to all periods presented, or (b) modified retrospective adoption, meaning the cumulative effect of applying the new standard is recognized as an adjustment to the opening retained earnings balance.

In July 2015, the FASB voted to amend ASU 2014-09 by approving a one-year deferral of the effective date as well as providing the option to early adopt the standard on the original effective date. Accordingly, we will adopt the standard for annual reporting period beginning after December 15, 2017, including interim periods within that reporting period. We are currently evaluating the alternative transition methods and the potential effects on our financial statements and future operating results.

In August 2014, the FASB issued ASU 2014-15, Presentation of Financial Statements-Going Concern (Subtopic 205-40): Disclosure of Uncertainties about an Entity’s Ability to Continue as a Going Concern. Under the new guidance, management will be required to assess an entity’s ability to continue as a going concern, and to provide related footnote disclosures in certain circumstances. The provisions of this ASU are effective for annual periods beginning after December 15, 2016, and for annual and interim periods thereafter. We are currently evaluating the potential changes from this ASU to our future financial reporting and disclosures.

2. Summary of Significant Accounting Policies

Use of Estimates

The Company’s financial statements are prepared in accordance with accounting principles generally accepted in the United States (“GAAP”). The preparation of the Company’s financial statements requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of expenses during the reporting period.

Reported amounts and note disclosures reflect the overall economic conditions that are most likely to occur and anticipated measures management intends to take. Actual results could differ materially from those estimates. All revisions to accounting estimates are recognized in the period in which the estimates are revised and in any future periods affected.

Concentration of Credit Risk

Financial instruments that potentially subject the Company to significant concentrations of credit risk consist primarily of cash. The Company maintains deposits in federally insured financial institutions in excess of federally insured limits and limits its exposure to cash risk by placing its cash with credit quality rating financial institutions.

Property and Equipment

Property and equipment are stated at cost and depreciated using the straight-line method over the estimated useful lives of the assets which is three years for each asset class.

Impairment of Long-Lived Assets

The Company reviews its long-lived assets for impairment whenever events or changes in circumstances indicate that the carrying value of an asset may not be recoverable. If such circumstances are determined to exist, an estimate of undiscounted future cash flows produced by the long-lived asset, including its eventual residual value, is compared to the carrying value to determine whether impairment exists. In the event that such cash flows are not expected to be sufficient to recover the carrying amount of the assets, the assets are written-down to their estimated fair values. While the Company’s current and historical operating losses and negative cash flows are indicators of impairment, the Company believes that future cash flows to be received support the carrying value of its long-lived assets and, accordingly, has not recognized any impairment losses through December 31, 2014.

Convertible Notes and Derivative Accounting

At inception, the Company performs an assessment of all embedded features of a debt instrument to determine if (1) such features should be bifurcated and separately accounted for, and (2) if bifurcation requirements are met, whether such features should be classified and accounted for as equity or liability. The fair value of the embedded feature is measured initially, included as a liability on the balance sheet, and remeasured each reporting period. Any changes in fair value are recorded in the statement of operations. The Company monitors, on an ongoing basis, whether events or circumstances could give rise to a change in its classification of embedded features.

The Company accounts for its convertible notes, that may be settled in cash upon conversion (including partial cash settlement), by separating the liability and equity components of the instruments in a manner that reflects the Company’s nonconvertible debt borrowing rate. The Company determines the carrying amount of the liability component by measuring the fair value of similar debt instruments that do not have the conversion feature. If a similar debt instrument does not exist, the Company estimates the fair value by using assumptions that market participants would use in pricing a debt instrument, including market interest rates, credit standing, yield curves and volatilities. Determining the fair value of the debt component requires the use of accounting estimates and assumptions. These estimates and assumptions are judgmental in nature and could have a significant impact on the determination of the debt component and the associated non-cash interest expense.

Deferred Rent

Deferred rent consists of the difference between cash payments and the recognition of rent expense on a straight-line basis for the facilities the Company occupies. The Company’s lease for its facilities provides for fixed increases in minimum annual rental payments. The total amount of rental payments due over the lease term is being charged to rent expense ratably over the life of the lease. The Company’s deferred rent balance is contained within other long-term liabilities on the Company’s Balance Sheet.

Research and Development Costs

Research and development costs are expensed as incurred. Research and development costs consist of direct and indirect internal costs related to specific projects as well as fees paid to other entities that conduct certain research activities on the Company’s behalf. Payments that the Company makes in connection with in-licensed technology for a particular research and development project that have no alternative future uses (in other research and development projects or otherwise) and therefore no separate economic values are expensed as research and development costs at the time such costs are incurred. As of December 31, 2014, the Company has no in-licensed technologies that have alternative future uses in research and development projects or otherwise.

Patent Costs

The Company expenses all costs as incurred in connection with patent applications, including direct application fees, and the legal and consulting expenses related to making such applications, and such costs are included in general and administrative expenses within the Company’s Statement of Operations and Comprehensive Loss.

Share-Based Compensation

Restricted stock awards are valued based on the fair value on the grant date. The fair value of restricted stock awards expected to vest are recognized on a straight-line basis over the requisite service period of the award. Restricted stock awards granted to non-employees are recorded at their fair value on the earlier of the performance commitment date or the date the services required are completed and are remeasured at fair value during the service period. As non-employee restricted stock awards vest, they are remeasured at fair value and expensed based on the intrinsic value method which is measured as the difference between the exercise price paid for the restricted stock award and the fair value of the shares as the right of the repurchase lapses each vesting period.

The Company’s equity incentive plan allows for the issuance of restricted stock awards to employees and non-employee consultants that may be subject to vesting. The unvested shares of any restricted stock awards are held in escrow as the stock award vests or until award holder termination, whichever occurs first. In the event of a termination, the Company has the right of repurchase, at its option, for the portion of unvested stock awards from the terminated award holder. The repurchase price for unvested stock awards will be the lower of (i) the fair market value of the shares of common stock on the date of repurchase or (ii) their original purchase price. For all unvested stock awards, a liability is established related to the cash received for the unvested portion of the stock award, which represents the Company’s obligation if all award holders were to be terminated, and is recorded within other long-term liabilities on the Company’s Balance Sheet.

Income Taxes

Income taxes have been accounted for using the asset and liability method. Under the asset and liability method, deferred tax assets and liabilities are recognized for the future tax consequences attributable to differences between the financial carrying amounts of existing assets and liabilities and their respective tax bases and operating loss and tax credit carryforwards. Deferred tax assets and liabilities are measured using enacted tax rates applicable to taxable income in the years in which those temporary differences are expected to be recovered or settled. The effect on deferred tax assets and liabilities of a change in tax rates is recognized in income in the period that includes the enactment date. A valuation allowance against deferred tax assets is recorded if, based upon the weight of all available evidence, it is more likely than not that some or all of the deferred tax assets will not be realized. For uncertain tax positions that meet “a more likely than not” threshold, the Company recognizes the benefit of uncertain tax positions in the financial statements.

Comprehensive Loss

The Company is required to report all components of comprehensive loss, including net loss, in the financial statements in the period in which they are recognized. Comprehensive loss is defined as the change in equity during a period from transactions and other events and circumstances from non-owner sources, including unrealized losses on investments. Net loss and comprehensive loss were the same for the period presented, therefore, a separate statement of comprehensive loss is not included in the accompanying financial statements.

Segment Reporting

Operating segments are components of an enterprise about which separate discrete financial information is available for evaluation by the chief operating decision-maker for purposes of making decisions regarding resource allocation and assessing performance. To date, the Company has viewed its operations and managed its business as one segment operating primarily in the United States.

Fair Value Measurements

The Company categorizes its assets and liabilities measured at fair value in accordance with the authoritative accounting guidance that establishes a consistent framework for measuring fair value, and expands disclosures for each major asset and liability category measured at fair value on either a recurring or nonrecurring basis. Fair value is defined as the exit price, representing the amount that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants. As such, fair value is a market-based measurement that should be determined based on assumptions that market participants would use in pricing an asset or liability. As a basis for considering such assumptions, the guidance establishes a three-tier fair value hierarchy, which prioritizes the inputs used in measuring fair value as follows:

•

Level 1- Quoted prices (unadjusted) in active markets for identical assets or liabilities;

•

Level 2- Inputs other than quoted prices included within Level 1 that are either directly or indirectly observable; and

•

Level 3- Unobservable inputs in which little or no market activity exists, therefore requiring an entity to develop its own assumptions about the assumptions that market participants would use in pricing.

At December 31, 2014, the Company did not have financial assets that are measured at fair value on a recurring basis. The carrying amounts of the Company’s financial instruments, which include cash, prepaid expenses, accounts payable, accrued expenses and all related party amounts approximate their fair values at December 31, 2014, primarily due to their short-term nature. The Company believes the fair value of its convertible notes approximates their carrying value as of December 31, 2014. No transfers between levels have occurred during the periods presented. Liabilities measured at fair value on a recurring basis as of December 31, 2014 are as follows, in thousands:


			Fair Value Measurements at December 31, 2014
	Balance as of December 31, 2014		Quoted Prices in Active Markets for Identical Assets (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)
*Liabilities*
Embedded derivative liability(1)	$	196	$	—	$	—	$	196

(1)

The Company’s license agreement with the with The Regents of the University of California San Francisco (“UCSF”), further described in Note 7, provides for an indexed milestone payment upon the occurrence of a qualified preferred stock financing and a subsequent initial public offering or a change of control event, as defined in the agreement. The indexed milestone was determined to qualify as an embedded derivative liability requiring an estimate of fair value.

The Company estimates the fair value of its derivative liabilities at the time of issuance and subsequent remeasurement at each reporting date using a probability model that considers the probability of achieving the events that would trigger such liabilities and the estimated time period the liabilities would be outstanding. The estimates are based, in part, on subjective assumptions and could differ materially in the future. Changes to these assumptions can have a significant impact on the fair value of the derivative liabilities.

The following table provides a reconciliation of all liabilities measured at fair value using Level 3 significant unobservable inputs, in thousands:


	Derivative Liabilities
Balance at August 22, 2014 (Inception)	$	—
Issuance of derivative liability(1)		196
Change in fair value(2)		—

Balance at December 31, 2014	$	196

(1)	The amount is included within research and development expenses on the Company’s Statement of Operations and Comprehensive Loss.

(2)	The license agreement was executed in November 2014 and no change in the valuation occurred between the execution date and December 31, 2014.

Net Loss per Share

Basic net loss per share is calculated by dividing the net loss by the weighted-average number of common shares outstanding for the period, without consideration for common stock equivalents. Diluted net loss per share is calculated by dividing the net loss by the weighted-average number of common share equivalents outstanding for the period determined using the treasury-stock method. Dilutive common stock equivalents are comprised of unvested restricted stock awards outstanding under the Company’s equity plan. For all periods presented, there is no difference in the number of shares used to calculate basic and diluted shares outstanding due to the antidilutive effect of the securities.

Potentially dilutive securities, which includes unvested stock awards of 4,532,874 are excluded from the calculation of diluted net loss per share due to the anti-dilutive effect of the securities. In addition, the Company has $2.5 million in principal of outstanding convertible promissory notes, issued in October and December 2014, that are convertible into common stock upon the occurrence of various future events at prices that are not determinable until the occurrence of those future events. As such, the Company has excluded these convertible notes payable from the calculation of diluted net loss per share.

Recent Accounting Pronouncements	12 Months Ended
Recent Accounting Pronouncements	Dec. 31, 2014
Accounting Changes and Error Corrections [Abstract]
Recent Accounting Pronouncements	3. Recent Accounting Pronouncements From time to time, new accounting pronouncements are issued by the Financial Accounting Standards Board (“FASB”) or other standard setting bodies that are adopted by the Company as of the specified effective date. Unless otherwise discussed, the Company believes that the impact of recently issued standards that are not yet effective will not have a material impact on our financial position or results of operations upon adoption. In May 2014, the FASB issued Accounting Standard Update (“ASU”) 2014-09, Revenue from Contracts with Customers (Topic 606), which will replace numerous requirements in U.S. GAAP, including industry-specific requirements, and provide companies with a single revenue recognition model for recognizing revenue from contracts with customers. The core principle of the new standard is that a company should recognize revenue to depict the transfer of promised goods or services to customers in an amount that reflects the consideration to which the company expects to be entitled in exchange for those goods or services. The new standard will be effective for annual reporting periods beginning after December 15, 2016, including interim periods within that reporting period. The Company is currently evaluating the impact the adoption of this guidance will have on its Financial Statements and future operating results. In June 2014, the FASB issued ASU 2014-10, Development Stage Entities (Topic 915), an accounting standards update that removes the financial reporting distinction between development stage entities and other reporting entities from GAAP. In addition, the amendments eliminate the requirements for development stage entities to: (1) present inception-to-date information in the statements of income, cash flows, and shareholder equity, (2) label the financial statements as those of a development stage entity, (3) disclose a description of the development stage activities in which the entity is engaged, and disclose in the first year in which the entity is no longer a development stage entity that in prior years it had been in the development stage. The guidance is effective prospectively for fiscal years, and interim periods within those years, beginning after December 15, 2014. The Company’s early adoption of the standard eliminated the requirement to disclose inception-to-date information or incremental financial reporting requirements related to development stage entities and does not have any additional impact on the Company’s financial statement or disclosures. In August 2014, the FASB issued ASU 2014-15, Presentation of Financial Statements-Going Concern (Subtopic 205-40): Disclosure of Uncertainties about an Entity’s Ability to Continue as a Going Concern. Under the new guidance, management will be required to assess an entity’s ability to continue as a going concern, and to provide related footnote disclosures in certain circumstances. The provisions of this ASU are effective for annual periods beginning after December 15, 2016, and for annual and interim periods thereafter. The Company is currently evaluating the potential changes from this ASU to its future financial reporting and disclosures.

- Definition

The entire disclosure of changes in accounting principles, including adoption of new accounting pronouncements, that describes the new methods, amount and effects on financial statement line items.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Glossary Change in Accounting Principle
-URI http://asc.fasb.org/extlink&oid=6507316

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Glossary Direct Effects of a Change in Accounting Principle
-URI http://asc.fasb.org/extlink&oid=6510796

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 250
-SubTopic 10
-Section 50
-Paragraph 3
-URI http://asc.fasb.org/extlink&oid=28359718&loc=d3e22583-107794

Reference 4: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Glossary Indirect Effects of a Change in Accounting Principle
-URI http://asc.fasb.org/extlink&oid=6515603

Reference 5: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 250
-SubTopic 10
-Section 50
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=28359718&loc=d3e22580-107794

Reference 6: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 270
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.10-01.(b)(6))
-URI http://asc.fasb.org/extlink&oid=27015980&loc=d3e46468-122699

Reference 7: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Glossary Accounting Change
-URI http://asc.fasb.org/extlink&oid=6503790

Reference 8: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 250
-SubTopic 10
-Section 50
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=28359718&loc=d3e22499-107794

Reference 9: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Glossary Retrospective Application
-URI http://asc.fasb.org/extlink&oid=6523989

Reference 10: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 270
-SubTopic 10
-Section 45
-Paragraph 13
-URI http://asc.fasb.org/extlink&oid=6372559&loc=d3e765-108305

Reference 11: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 270
-SubTopic 10
-Section 45
-Paragraph 12
-URI http://asc.fasb.org/extlink&oid=6372559&loc=d3e725-108305

Reference 12: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Section 01
-Paragraph b
-Subparagraph 6
-Article 10

+ Details

Property and equipment, net

6 Months Ended

12 Months Ended

Jun. 30, 2015

Dec. 31, 2014

Property, Plant and Equipment [Abstract]

Property and equipment, net

6. Property and Equipment, Net

Property and equipment consisted of the following, in thousands:


	June 30, 2015			December 31, 2014
Computer equipment	$	59		$	26
Software		7			2

		66			28
Less: accumulated depreciation		(7	)		(1	)

Property and equipment, net	$	59		$	27

4. Property and equipment, net

Property and equipment consisted of the following, in thousands:


	December 31, 2014
Computer equipment	$	26
Software		2

		28
Less: accumulated depreciation		(1	)

Property and equipment, net	$	27

Accounts Payable and Accrued Liabilities

6 Months Ended

12 Months Ended

Jun. 30, 2015

Dec. 31, 2014

Payables and Accruals [Abstract]

Accounts payable and accrued liabilities

7. Accounts Payable and Accrued Liabilities

Accounts payable and accrued liabilities consisted of the following, in thousands:


	June 30, 2015		December 31, 2014
Accounts payable	$	715	$	226
Accrued expenses		1,193		581
Accrued compensation and benefits		584		39

Total accounts payable and accrued expenses	$	2,492	$	846

5. Accounts payable and accrued liabilities

Accounts payable and accrued liabilities consisted of the following, in thousands:


	December 31, 2014
Accounts payable	$	226
Accrued expenses		568
Accrued compensation and benefits		39

Total accounts payable and accrued expenses	$	833

Notes Payable

6 Months Ended

12 Months Ended

Jun. 30, 2015

Dec. 31, 2014

Debt Disclosure [Abstract]

Notes Payable

8. Notes Payable

Araxes Convertible Note

In October 2014, we entered into a Note Purchase Agreement and Convertible Promissory Note with an affiliated company Araxes Pharma LLC, or Araxes, under which Araxes provided a $2.0 million loan in the form of a convertible promissory note. As a result of the Financing, the total of unpaid principal and accrued interest as of February 28, 2015 was automatically converted into 326,443 shares of our common stock.

Araxes Asset Purchase Agreement — Convertible Note

As consideration for the patents acquired under the Araxes Asset Purchase Agreement entered into in December 2014, Araxes issued a convertible promissory note equal to the purchase price of the patent rights of $500,000. As a result of the Financing, the total of unpaid principal and accrued interest as of February 28, 2015 was automatically converted into 80,293 shares of our common stock.

January 2015 Convertible Notes

In January 2015, we entered into a Note Purchase Agreement and Convertible Promissory Note for a $3.0 million loan with various persons and entities named within the agreement, or the Holders, of which $710,000 were with certain officers and certain officers’ related parties. As a result of the Financing, the total of unpaid principal and accrued interest as of February 28, 2015 was automatically converted into 479,667 shares of our common stock.

JJDC Convertible Note

In accordance with the license agreement with Janssen Pharmaceutica NV, or Janssen, a foreign entity headquartered in Belgium and an affiliate of Johnson & Johnson, Inc., in January 2015 we entered into a Convertible Promissory Note with Janssen’s affiliated company, Johnson & Johnson Innovation — JJDC, Inc., or JJDC, for $1.0 million. As a result of the Financing, the total of unpaid principal and accrued interest as of February 28, 2015 was automatically converted into 159,615 shares of our common stock.

February 2015 Convertible Notes

In February 2015, we entered into a Note Purchase Agreement and Convertible Promissory Note with entities named within the agreement, or the February Note Holders, under which the February Note Holders provided a $1.0 million loan in the form of convertible promissory notes. As a result of the Financing, the total of unpaid principal and accrued interest as of February 28, 2015 was automatically converted into 158,852 shares of our common stock.

6. Notes Payable

Araxes Convertible Note

On October 8, 2014, the Company entered into a Note Purchase Agreement and Convertible Promissory Note with its affiliated company Araxes Pharma LLC (“Araxes”) under which Araxes provided a $2.0 million loan in the form of a convertible promissory note. The note contains interest computed at a rate of 8%, compounded annually, with a maturity date of the earliest to occur of: (i) December 31, 2015, (ii) upon a change in control, as defined in the agreement, or (iii) upon defined events of default. Interest is due and payable on the maturity date. Prepayment of principal or interest is not allowed on the note without the prior written consent of Araxes. The note is automatically converted into such class of stock of the Company issued upon the completion of a qualified initial public offering (“IPO”) or upon the completion of a qualified financing, as defined in the agreement, in an amount equal to the total unpaid principal and interest divided by the price per share offered to the public in the qualified IPO or the price per share of the equity securities paid by other investors in a qualified financing. The Convertible Promissory Note contains customary events of default, and is recorded at its redemption amount, or at cost, within notes payable- related party, current on the Company’s Balance Sheet.

Araxes Asset Purchase Agreement—Convertible Note

As consideration for the patents acquired under the Araxes Asset Purchase agreement entered into on December 23, 2014 (described further in Note 7), Araxes issued a convertible promissory note equal to the purchase price of the patent rights of $500,000. The note contains interest computed at a rate of 8% with a maturity date of the earliest to occur: (i) of May 31, 2016 (ii) upon a change in control, as defined in the agreement, or (iii) upon defined events of default. The note may not be prepaid. The note will automatically convert into such class of stock of the Company issued upon the completion of a qualified equity financing at the lowest per share price offered in the round. The Convertible Promissory Note contains customary events of default, and is recorded at its redemption amount within notes payable-related party, noncurrent on the Company’s Balance Sheet.

Total notes payable and unamortized discount balances are as follows, in thousands:


	December 31, 2014
Face value of convertible notes	$	2,500
Accrued interest		36
Debt issuance costs associated with fair value of derivative		(7	)

Total	$	2,529
Less: current portion		(2,036	)

Total convertible notes, long-term	$	493

License Agreements	6 Months Ended	12 Months Ended
License Agreements	Jun. 30, 2015	Dec. 31, 2014
License Agreements [Abstract]
License Agreements	9. License Agreements License Agreement with The University of Michigan In December 2014, we entered into a license agreement with The Regents of The University of Michigan, or Michigan, under which we received certain license rights for a non-refundable upfront license, annual maintenance fees and payments upon achievement of certain development and sales-based milestones. The licensed asset consists of a number of compounds, which are in the lead discovery/lead optimization phase. All future development, regulatory and commercial work on the asset will be completed fully and at our sole expense. Michigan retains the right to use the asset for non-commercial research, internal and/or educational purposes, with the right to grant the same limited rights to other non-profit research institutions. Furthermore, the agreement stipulates contingent consideration for the issuance of shares equivalent to a set dollar value upon the occurrence of a qualified financing or a change of control event, as defined in the amendment to the agreement, consistent with the terms issued to any future investors or the per share consideration to be received by other shareholders. As a result of the Financing, we issued 79,113 shares of our common stock at a fair value of $500,000, which was recognized as research and development expense during the six months ended June 30, 2015. The agreement will terminate upon the last-to-expire patent rights, or may be terminated by us at any time with 90 days written notice of termination or terminated by Michigan upon a bankruptcy by us, payment failure by us that is not cured within 30 days or a material breach of the agreement by us that is not cured within 60 days. Sponsored Research Agreement with The University of Michigan In February 2015, we entered into a Sponsored Research Agreement with Michigan under which we will sponsor up to $2.7 million of research at Michigan over a three-year period. We will receive a non-exclusive right to any technology developed under this agreement and have an option right for an exclusive right to any such licenses developed under the agreement. The Sponsored Research Agreement allows for termination with notice at any time by us. In the event of termination by us prior to the second anniversary of the agreement, other than due to breach by Michigan, we will be required to pay costs budgeted through the second anniversary up to $2.0 million of the sponsored research amount. Any costs incurred for the Sponsored Research Agreement will be expensed as incurred. For the three and six months ended June 30, 2015, we recorded approximately $251,000 and $376,000, respectively, in research and development expense under this research agreement. Collectively, our outstanding license agreements provide for specified development, regulatory and sales-based milestone payments up to a total of $81.7 million payable upon occurrence of each stated event, of which $1.2 million relates to the initiation of certain development activities, $30.5 million relates to the achievement of specified regulatory approvals for the first indication and up to $50.0 million for the achievement of specified levels of product sales. Additional payments will be due for each subsequent indication if specified regulatory approvals are achieved. All milestone payments under the agreements will be recognized as research and development expense upon completion of the required events because the triggering events are not considered to be probable until they are achieved. As of June 30, 2015, we have not achieved any milestones under the agreements. Furthermore, if all the programs are successfully commercialized, we will be required to pay tiered royalties on annual net product sales ranging from the low single digits to the low teens, depending on the volume of sales and the respective agreement.	7. License and Asset Purchase Agreements Janssen License Agreement On December 18, 2014, the Company entered into a license agreement with Janssen Pharmaceutica NV (“Janssen”), a foreign entity headquartered in Belgium and an affiliate of Johnson & Johnson, Inc., under which the Company received certain intellectual property rights related to tipifarnib in the field of oncology for a non-refundable $1.0 million upfront license fee and payments upon achievement of certain development and sales-based milestones. Tipifarnib is a clinical stage compound and all ongoing development, regulatory and commercial work will be completed fully and at the sole expense of the Company. Under the license agreement, Janssen has a first right to negotiate for an exclusive license back from the Company to develop and commercialize tipifarnib on terms to be negotiated in good faith. Janssen may exercise this right of first negotiation during a 60-day period following delivery of clinical data as specified in the agreement. The agreement will terminate upon the last-to-expire patent rights or last-to-expire royalty term, or may be terminated by the Company with 180 days written notice of termination. Either party may terminate the agreement in the event of material breach of the agreement that is not cured within 45 days. Janssen may also terminate the agreement due to the Company’s lack of diligence that is not cured within a three-month period. The upfront license fee was paid in January 2015. Subsequent to such payment, in accordance with the agreement the Company entered into a convertible promissory note with Janssen’s affiliated company, Johnson & Johnson Innovation—JJDC, Inc. (“JJDC”) as described further in Note 13. Due to the long-term nature of the note, the full amount of the unpaid upfront fee is included within other long-term liabilities on the Company’s Balance Sheet as of December 31, 2014. The University of Michigan License Agreement On December 22, 2014, the Company entered into a license agreement with The Regents of The University of Michigan (“Michigan”) under which the Company received certain license rights for a non-refundable upfront license, annual maintenance fees and payments upon achievement of certain development and sales-based milestones. The licensed asset consists of a number of compounds, which are in the lead discovery/lead optimization phase. All future development, regulatory and commercial work on the asset will be completed fully and at the sole expense of the Company. Michigan retains the right to use the asset for non-commercial research, internal and/or educational purposes, with the right to grant the same limited rights to other non-profit research institutions. Furthermore, the agreement, as amended on March 3, 2015, stipulates contingent consideration for the issuance of shares equivalent to a set dollar value upon the occurrence of a qualified capital stock financing or a change of control event, as defined in the amended agreement, consistent with the terms issued to any future investors or the per share consideration to be received by other shareholders. See Note 13 for further discussion. The agreement will terminate upon the last-to-expire patent rights, or may be terminated by the Company at any time with 90 days written notice of termination or terminated by Michigan upon a bankruptcy by the Company, payment failure by the Company that is not cured within 30 days or a material breach of the agreement by the Company that is not cured within 60 days. The University of San Francisco License Agreement On November 21, 2014, the Company entered into a license agreement with UCSF under which the Company received certain license rights. The agreement provided for an upfront payment as well as contingent milestone payments. Additionally, the agreement provides for a one-time indexed milestone payment upon the occurrence of an initial public offering or a change of control event following a qualified financing, as defined in the agreement. The indexed milestone was determined to qualify as an embedded derivative liability requiring an estimate of fair value. See Note 2 for further detail. Collectively, the license agreements with Janssen, Michigan and UCSF provided for non-refundable upfront payments totaling $1.1 million. Each of these license agreements was individually deemed an asset acquisition, which required the Company to expense the full upfront acquisition price due to the preliminary stage of development and no identified alternative future use upon the agreement execution date. The expense is included within research and development expenses in the Company’s Statement of Operations and Comprehensive Loss. In addition, the license agreements collectively provide for specified development, regulatory and sales-based milestone payments up to a total of $81.7 million payable upon occurrence of each stated event, of which $1.2 million relates to the initiation of certain development activities, $30.5 million relates to the achievement of specified regulatory approvals for the first indication and up to $50.0 million for the achievement of specified levels of product sales. Additional payments will be due for each subsequent indication if specified regulatory approvals are achieved. All milestone payments under the agreement will be recognized as research and development expense upon completion of the required events because the triggering events are not considered to be probable until they are achieved. As of December 31, 2014, the Company has not achieved any milestones under the agreements. Furthermore, if all the programs are successfully commercialized, the Company will be required to pay tiered royalties on annual net product sales ranging from the low single digits to the low teens, depending on the volume of sales and the respective agreement. Araxes Asset Purchase Agreement On December 23, 2014, the Company entered into an asset purchase agreement with Araxes under which the Company purchased certain early stage patent rights related to compounds in the field of oncology for a purchase price of $500,000 payable under a convertible promissory note. All ongoing development, regulatory and commercial work will be completed fully and at the sole expense of the Company. The agreement allows for contingent milestone payments of $9.7 million throughout development and commercialization of the asset, of which $1.2 million relates to the initiation of certain development activities, and $8.5 million relates to the submission of certain regulatory filings and receipt of certain regulatory approvals. Additional payments will be due for each subsequent indication if specified regulatory approvals are achieved. The Company will recognize the milestones as expense when each event occurs. As of December 31, 2014, the Company has not achieved any milestones under the agreement. Furthermore, if the program is successfully commercialized, the Company will be required to pay tiered royalties on annual net product sales ranging in the low single digits, depending on the volume of sales. The transaction was deemed an asset acquisition, which required the Company to expense the full upfront acquisition price due to the preliminary stage of development and no identified alternative future use upon the agreement execution date and is included within research and development expenses, related party in the Company’s Statement of Operations and Comprehensive Loss. All additional milestone payments under the agreement will be recognized upon completion of the required events because the triggering events will not be considered to be probable until they are achieved.

Commitments and Contingencies

6 Months Ended

12 Months Ended

Jun. 30, 2015

Dec. 31, 2014

Commitments and Contingencies Disclosure [Abstract]

Commitments and Contingencies

10. Commitments and Contingencies

From time to time, we may be involved in disputes, including litigation, relating to claims arising out of operations in the normal course of our business. Any of these claims could subject us to costly legal expenses and, while we generally believe that we have adequate insurance to cover many different types of liabilities, our insurance carriers may deny coverage or our policy limits may be inadequate to fully satisfy any damage awards or settlements. If this were to happen, the payment of any such awards could have a material adverse effect on our results of operations and financial position. Additionally, any such claims, whether or not successful, could damage our reputation and business. We currently are not a party to any legal proceedings, the adverse outcome of which, in management’s opinion, individually or in the aggregate, would have a material adverse effect on our results of operations or financial position.

8. Commitments and Contingencies

On August 29, 2014, the Company entered into a sublease agreement (the “sublease”) with its affiliated company, Araxes, for office space for a monthly rent of approximately $5,000 per month. The lease includes rent escalation of 3% per year. The lease was amended on December 18, 2014 for monthly rent of approximately $5,000 per month and retrospectively applied from September 1, 2014 in accordance with the agreement. In addition to the base monthly rent, the Company is obligated to pay for operating expenses, taxes, insurance, and utilities applicable to the subleased property. The sublease will expire on August 30, 2016.

On September 30, 2014, the Company entered into a lease agreement (the “lease”) with Regus for office space located in Cambridge, Massachusetts. The lease commenced on October 6, 2014 with monthly rent of approximately $5,000 per month. Rent expense is recognized using the straight-line method over the term of the lease. In addition to the base monthly rent, the Company is obligated to pay for operating expenses, taxes, insurance and utilities applicable to the leased property. The lease will expire on October 31, 2016.

Future minimum payments required under the leases as of December 31, 2014 are summarized as follows, in thousands:


Year Ending December 31,
2015	$	111
2016		88

Total minimum lease payments	$	199

Total lease expense for the period from August 22, 2014 (inception) to December 31, 2014 was $27,000.

The Company is obligated to make a charitable gift of $285,000 to the Leukemia and Lymphoma Society in connection with the Michigan agreement described in Note 7 to be paid in three equal parts: the first part due in January 2015, the second part due in January 2016 and the final part due in January 2017. The full amount of the charitable gift has been accrued as of December 31, 2014.

Stockholders' Equity

6 Months Ended

12 Months Ended

Jun. 30, 2015

Dec. 31, 2014

Equity [Abstract]

Stockholders' Equity

11. Stockholders’ Equity

Immediately prior to the Merger, on March 6, 2015, Prior Kura sold 8,280,696 shares of our common stock at a price of $6.32 per share, for net proceeds of approximately $48.2 million, net of $4.1 million in fees. The Financing represented a qualified financing conversion event pursuant to the Notes. As such, upon the closing of the Financing, an aggregate of $7.5 million in principal under the Notes and $115,000 in accrued interest through February 28, 2015 automatically converted into 1,204,870 shares of our common stock. In addition, we incurred approximately $568,000 in costs related to the Merger which were accounted for as financing costs in additional paid-in capital.

Effective April 13, 2015, pursuant to our amended and restated certificate of incorporation, we have authorized capital stock consisting of 200,000,000 shares of common stock, par value $0.0001 per share, and 10,000,000 shares of preferred stock, par value $0.0001 per share.

9. Stockholders’ Equity

Common Stock

As of December 31, 2014, 556,500 shares were reserved for future issuance pursuant to shares authorized for future option grants. In addition, the Company has $2.5 million in principal of outstanding convertible promissory notes, issued in October and December 2014, that are convertible into stock upon the occurrence of various future events at prices that are not determinable until the occurrence of those future events.

Restricted Stock Awards

In August 2014, the Company adopted the 2014 Equity Incentive Plan (the “2014 Plan”). A total of 5,500,000 shares were initially reserved for issuance under the 2014 Plan. The 2014 Plan provides equity-based incentives in the form of stock awards to employees and other providers of services to the Company. The 2014 Plan provides for the grant of incentive stock options, non-statutory stock options, stock appreciation rights, restricted stock awards, restricted stock unit awards, and other stock awards to eligible recipients. Recipients of incentive stock options shall be eligible to purchase shares of the Company’s common stock at an exercise price equal to no less than the estimated fair market value of such stock on the date of grant. The maximum term of options to be granted under the 2014 Plan is ten years. No options were granted under the 2014 Plan as of December 31, 2014.

Restricted stock awards were granted at a price equal to estimated fair market value. The restricted stock awards generally vest over four years from the original vesting date, with certain grants subject to one-year cliff vesting. The vesting provisions of individual awards may vary as approved by the Company’s Board of Directors. In connection with the issuance of restricted common stock, the Company maintains a repurchase right where shares of restricted common stock are released from such repurchase right over a period of time of continued service by the recipient. The following is a summary of restricted share activity, in thousands, except per share data:


	Number of Shares			Weighted Average Grant Date Fair Value
Balance at August 22, 2014 (Inception)		—		$	—
Granted		4,944		$	0.002
Vested		(411	)

Unvested at December 31, 2014		4,533		$	0.002

Vested at December 31, 2014		411		$	0.002

The shares purchased by the recipients pursuant to unvested restricted stock awards are not deemed, for accounting purposes, to be outstanding until those shares vest. The cash received in exchange for unvested shares related to stock awards granted is recorded as a liability for the early exercise of stock options on the accompanying balance sheet and will be transferred into common stock and additional paid-in capital as the shares vest. As of December 31, 2014, the Company recorded $13,000 of liability associated with shares issued with repurchase rights, of which $10,000 and $3,000 was related to employee and non-employee restricted stock awards, respectively.

During the period from August 22, 2014 (inception) to December 31, 2014, the Company granted 4,096,000 and 847,500 shares underlying restricted stock awards to employees and non-employees, respectively, at a weighted average price of $0.002. All employee and non-employee restricted stock awards vest over a four-year period beginning on the vesting commencement date. Certain non-employee restricted stock award agreements provide for acceleration of vesting prior to the completion of the service period upon the occurrence of specified events, including the Merger. As of December 31, 2014, there were 4,532,874 shares subject to repurchase, of which 3,773,916 and 758,958 shares were related to employee and non-employee restricted stock awards, respectively. As of December 31, 2014, 556,500 shares of common stock were reserved for future stock awards under the 2014 Plan.

For the period from August 22, 2014 (inception) to December 31, 2014, 322,084 and 88,542 shares underlying restricted stock awards granted to employees and non-employees, respectively, vested. The Company recognized $237,000 in share-based compensation expense related to the vested portion of the restricted stock awards granted to non-employees for the period from August 22, 2014 (inception) to December 31, 2014, of which $233,000 was charged to research and development expense and $4,000 to general and administrative expense. There was no share-based compensation expense recognized related to employee awards because the Company received proceeds equal to grant date estimated fair value of the employee awards.

- Definition

The entire disclosure for shareholders' equity comprised of portions attributable to the parent entity and noncontrolling interest, including other comprehensive income. Includes, but is not limited to, balances of common stock, preferred stock, additional paid-in capital, other capital and retained earnings, accumulated balance for each classification of other comprehensive income and amount of comprehensive income.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 235
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08.(d),(e))
-URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e23780-122690

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 4
-URI http://asc.fasb.org/extlink&oid=6928386&loc=d3e21484-112644

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SAB TOPIC 4.E)
-URI http://asc.fasb.org/extlink&oid=27010918&loc=d3e74512-122707

Reference 4: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 5
-URI http://asc.fasb.org/extlink&oid=6928386&loc=d3e21488-112644

Reference 5: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.29-31)
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 6: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section S99
-Paragraph 4
-Subparagraph (SAB TOPIC 4.C)
-URI http://asc.fasb.org/extlink&oid=27012166&loc=d3e187143-122770

Reference 7: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 6
-URI http://asc.fasb.org/extlink&oid=6928386&loc=d3e21506-112644

Reference 8: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.3-04)
-URI http://asc.fasb.org/extlink&oid=27012166&loc=d3e187085-122770

Reference 9: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 30
-Section 50
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=6405834&loc=d3e23285-112656

Reference 10: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 3
-URI http://asc.fasb.org/extlink&oid=6928386&loc=d3e21475-112644

Reference 11: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Glossary Preferred Stock
-URI http://asc.fasb.org/extlink&oid=6521494

Reference 12: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=6928386&loc=d3e21463-112644

Reference 13: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 11
-URI http://asc.fasb.org/extlink&oid=6928386&loc=d3e21564-112644

Reference 14: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Section 08
-Paragraph d
-Article 4

Reference 15: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Section 02
-Paragraph 29, 30, 31
-Article 5

Reference 16: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Staff Accounting Bulletin (SAB)
-Number Topic 4
-Section E

Reference 17: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Section 08
-Article 4

Reference 18: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Staff Accounting Bulletin (SAB)
-Number Topic 4
-Section C

Reference 19: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Section 04
-Article 3

+ Details

Related Party Transactions	6 Months Ended	12 Months Ended
Related Party Transactions	Jun. 30, 2015	Dec. 31, 2014
Related Party Transactions [Abstract]
Related Party Transactions	13. Related Party Transactions As discussed in Note 8, in January 2015, we entered into a Note Purchase Agreement and Convertible Promissory Note for a $3.0 million loan with the Holders, of which $710,000 were with certain officers and certain officers’ related parties. As a result of the Financing, the total of unpaid principal and accrued interest as of February 28, 2015 was automatically converted into 479,667 shares of our common stock. Our president and chief executive officer is also the managing member of our affiliated company Araxes. Four individuals are significant stockholders of each of us and Araxes. The following is a summary of all transactions with Araxes for the six months ended June 30, 2015: Convertible Promissory Notes As described in Note 8, as a result of the Financing, the total of unpaid principal and accrued interest as of February 28, 2015 for the convertible note payable to Araxes was automatically converted into 326,443 shares of our common stock. In addition, the total of unpaid principal and accrued interest as of February 28, 2015 for the convertible note payable related to the Araxes asset purchase was automatically converted into 80,293 shares of our common stock. Facility Sublease We sublease office space from Araxes for a base rent of approximately $5,000 per month plus operating expenses, taxes, insurance, and utilities applicable to the subleased property. Rent expense related to this sublease for the three and six months ended June 30, 2015 was $24,000 and $49,000, respectively. The sublease will expire on August 30, 2016. Management Fees We have a management services agreement with Araxes under which Araxes pays us a fixed $100,000 a month for management services. In addition, the agreement allows for Araxes to pay us an amount equal to the number of full time equivalents, or FTE, performing collaboration services for Araxes, at an annual FTE rate of $350,000, plus actual expenses as reasonably incurred. The agreement has an initial term expiring on December 31, 2015 and renews automatically for additional consecutive one-year periods. The agreement may be terminated by either party with a notice of at least 30 days prior to December 31, 2015 or the expiration of the then-renewal term. Services Agreement We have a services agreement with Wellspring Biosciences LLC (a wholly owned subsidiary of Araxes) which allows for payment of research and development services provided to us of an amount equal to the number of FTE’s performing the services, at an annual FTE rate of $400,000, plus actual expenses as reasonably incurred. This services agreement has an initial term expiring on December 31, 2015 and renews automatically for additional consecutive one-year periods. The agreement may be terminated by either party with a notice of at least 30 days prior to December 31, 2015 or the expiration of the then-renewal term.	10. Related Party Transactions The Company’s president and chief executive officer is also the managing member of its affiliated company, Araxes. Four individuals are significant stockholders of each of the Company and Araxes. The following is a summary of all transactions with Araxes from August 22, 2014 (inception) to December 31, 2014. Convertible Promissory Notes As described in Note 6, the Company entered into a Note Purchase Agreement and Convertible Promissory Note with Araxes under which Araxes provided a $2.0 million loan in the form of a convertible promissory note. The note is included within notes payable, related party, current on the Company’s Balance Sheet. Additionally, in conjunction with the asset purchase agreement with Araxes described in Note 7, the Company purchased assets for an upfront purchase price of $500,000 payable under a convertible promissory note. This amount is included with research and development expenses, related party on the Company’s Statement of Operations and Comprehensive Loss. Additionally, the note is included within notes payable, related party, noncurrent on the Company’s Balance Sheet. Facility Sublease As noted in Note 8, the Company subleases office space from Araxes for a monthly rent of approximately $5,000 per month. In addition to the base monthly rent, the Company is obligated to pay for operating expenses, taxes, insurance, and utilities applicable to the subleased property. Rent expense related to this sublease for the period from August 22, 2014 (inception) to December 31, 2014 was $15,000. The sublease will expire on August 30, 2016. Management Fees The Company has a management services agreement with Araxes under which Araxes pays the Company a fixed $100,000 a month for management services. In addition, the agreement allows for Araxes to pay the Company an amount equal to the number of full time equivalents (“FTE”) performing collaboration services for Araxes, at an FTE rate of $350,000, plus actual expenses as reasonably incurred. The agreement has an initial term expiring on December 31, 2015 and renews automatically for additional consecutive one-year periods. The agreement may be terminated by either party with a notice of at least 30 days prior to December 31, 2015 or the expiration of the then-renewal term. Services Agreement The Company has a services agreement with Araxes which allows for payment of research and development services provided to the Company of an amount equal to the number of FTE’s performing the services, at an FTE rate of $400,000, plus actual expenses as reasonably incurred. This services agreement has an initial term expiring on December 31, 2015 and renews automatically for additional consecutive one-year periods. The agreement may be terminated by either party with a notice of at least 30 days prior to December 31, 2015 or the expiration of the then-renewal term.

- Definition

The entire disclosure for related party transactions. Examples of related party transactions include transactions between (a) a parent company and its subsidiary; (b) subsidiaries of a common parent; (c) and entity and its principal owners; and (d) affiliates.

+ References + Details

Employee Benefit Plan	12 Months Ended
Employee Benefit Plan	Dec. 31, 2014
Postemployment Benefits [Abstract]
Employee Benefit Plan	11. Employee Benefit Plan The Company has a defined contribution 401(k) plan (the “Plan”) for all employees. Employees are eligible to participate in the Plan if they are at least 21 years of age or older. Under the terms of the Plan, employees may make voluntary contributions as a percentage of compensation.

Income Taxes

12 Months Ended

Dec. 31, 2014

Income Tax Disclosure [Abstract]

Income Taxes

12. Income Taxes

The Company was incorporated on August 22, 2014 and will file tax returns as prescribed by the tax laws of the jurisdictions in which it operates. In the normal course of business, the Company’s 2014 tax year will be subject to examination by the federal and state jurisdictions where applicable. The Company has not been, nor is it currently, under examination by the federal or any state tax authority.

The Company’s effective income tax differs from the statutory federal rate of 34% at December 31, 2014 due to the following, in thousands:


	Period from August 22, 2014 (Inception) to December 31, 2014
Benefit for income taxes at statutory federal rate	$	(1,248	)
State income tax (benefit), net of federal benefit		(225	)
Share-based compensation		80
Research and development tax credits		(28	)
Other		13
Valuation allowance		1,408

Income tax expense	$	—

Significant components of the Company’s deferred tax assets at December 31, 2014 are shown below, in thousands:


	December 31, 2014
Deferred tax assets
Intangibles	$	732
Net operating loss carryforwards		442
Research and development tax credit carryforwards		28
Accruals		205
Other		1

Total deferred tax assets		1,408
Less valuation allowance		(1,408	)

Net deferred tax assets	$	—

At December 31, 2014, the Company had federal and state net operating loss carryforwards of $1.1 million and $1.2 million respectively. The federal and state loss carryforwards begin to expire in 2034, unless previously utilized. The Company also has federal and state research credit carryforwards of $18,000 and $16,000, respectively. The federal and Massachusetts research credits will begin expiring in 2034 and 2029, respectively, unless previously utilized. The California research credit will carryforward indefinitely.

Management assesses the available positive and negative evidence to estimate if sufficient future taxable income will be generated to use existing deferred tax assets. Based on the weight of the evidence, including the Company’s limited existence and losses since inception, management has determined that it is more likely than not that the deferred tax assets will not be realized. A valuation allowance of $1.4 million for the period ended December 31, 2014 has been established to offset the deferred tax assets as realization of such assets is uncertain.

Pursuant to Internal Revenue Code (“IRC”) Sections 382 and 383, annual use of the Company’s net operating loss and research and development credit carryforwards may be limited in the event a cumulative change in ownership of more than 50% occurs within a three-year period. The Company has not completed an IRC Section 382/383 analysis regarding the limitation of net operating loss and research and development credit carryforwards. The Company does not expect this analysis to be completed within the next 12 months. Due to the existence of the valuation allowance, future changes in the Company’s unrecognized tax benefits will not impact the Company’s effective tax rate. Any carryforwards that will expire prior to utilization as a result of such limitations will be removed from deferred tax assets, with a corresponding reduction of the valuation allowance.

The impact of an uncertain income tax position is recognized at the largest amount that is “more likely than not” to be sustained upon audit by the relevant taxing authority. An uncertain tax position will not be recognized if it has less than a 50% likelihood of being sustained. There are no unrecognized tax benefits included in the Company’s balance sheet at December 31, 2014. The Company’s practice is to recognize interest and penalties related to income tax matters in income tax expense. The Company has not recognized interest or penalties in its statement of operations for the period ended December 31, 2014.

The Company does not expect that there will be a significant change in the unrecognized tax benefits over the next twelve months. Due to the existence of the valuation allowance, future changes in the Company’s unrecognized tax benefits will not impact the Company’s effective tax rate.

Subsequent Events	6 Months Ended	12 Months Ended
Subsequent Events	Jun. 30, 2015	Dec. 31, 2014
Subsequent Events [Abstract]
Subsequent Events	14. Subsequent Events We evaluated subsequent events through August 14, 2015, the date the financial statements for the three and six months ended June 30, 2015 were issued. *Cambridge Facilities Lease* In August 2015, we entered into a lease agreement for approximately 3,677 square feet of office space located in Cambridge, Massachusetts. We paid a security deposit of approximately $44,000. The lease is subject to a 60 month term, with initial monthly rent of approximately $21,000 per month, and subject to a 1.4% annual rent increase. Total base rent payable over the lease period is $1.3 million. In addition to base monthly rent, we are obligated to pay for operating expenses, taxes, insurance and utilities applicable to the leased property.	13. Subsequent Events The Company evaluated all events or transactions that occurred after the balance sheet date of December 31, 2014 through March 12, 2015. Note Purchase Agreement On January 12, 2015, the Company entered into a Note Purchase Agreement and Convertible Promissory Note with various persons and entities named within the agreement (“the Holders”) under which the Holders provided a $3.0 million loan in the form of a convertible promissory note (“the Note”) to be used solely to fund the operations of the Company. The Note contains interest computed at a rate of 8%, compounded annually, with a maturity date of the earliest to occur of: (i) December 31, 2015, (ii) upon a change in control, as defined in the agreement, or (iii) upon defined events of default. Interest is due and payable on the maturity date. Prepayment of principal or interest is not allowed on the Note without the prior written consent of the holders. The Note is mandatorily convertible into such class of stock of the Company issued upon the completion of a qualified initial public offering or qualified financing, as defined in the agreement, in an amount equal to the total unpaid principal and interest divided by the price per share offered to the public in the qualified IPO or the price per share of the equity securities paid by other investors in a qualified financing. Convertible Promissory Note On January 20, 2015, in accordance with the Janssen license agreement described in Note 7, the Company entered into a Convertible Promissory Note with JJDC for $1.0 million. The note contains interest computed at a rate of 8% with a maturity date of the earliest to occur of: (i) May 31, 2016, (ii) upon a change in control, as defined in the agreement, or (iii) upon defined events of default. Interest is due and payable on the maturity date, with prepayment of principal or interest not allowed. The note will automatically convert into such class of shares of the Company issued upon the completion of a qualified equity financing at the lowest per share price offered in the round. February 2015 Note Purchase Agreement On February 11, 2015, the Company entered into a Note Purchase Agreement and Convertible Promissory Notes with entities named within the agreement (“the February 2015 Note Holders”) under which the February 2015 Note Holders provided totaling $1.0 million loan in the form of convertible promissory notes. These Convertible Promissory Notes contain interest computed at a rate of 8%, compounded annually, with a maturity date of the earliest to occur of: (i) December 31, 2015, (ii) upon a change in control, as defined in the agreement, or (iii) upon defined events of default. Interest is due and payable on the maturity date. Prepayment of principal or interest is not allowed on the note without the prior written consent of the holders. The notes will automatically convert into such class of stock of the Company issued upon the completion of a qualified initial public offering or qualified financing, as defined in the agreement, in an amount equal to the total unpaid principal and interest divided by the price per share offered to the public in the qualified IPO or the price per share of the equity securities paid by other investors in a qualified financing. Sponsored Research Agreement On February 15, 2015, the Company entered into a Sponsored Research Agreement with Michigan under which the Company will sponsor up to $2.7 million of research at Michigan over a three-year period. The Company will receive an non-exclusive right to any technology developed under the agreement and has an option right for an exclusive right to any such licenses developed under the agreement. The Sponsored Research Agreement allows for termination with notice at any time by the Company. In the event of termination by the Company prior to the second anniversary of the agreement, other than due to breach by Michigan, the Company will be required to pay costs budgeted through the second anniversary up to $2.0 million of the sponsored research amount. Any costs incurred for the Sponsored Research Agreement will be expensed as incurred. Michigan Amended License Agreement On March 3, 2015, the Company and Michigan entered into an amendment to the Michigan license agreement which redefined a qualified financing as the first sale of the Company’s capital stock in which the Company receives certain gross proceeds from the financing. The sale of the Company’s common stock on March 6, 2015 as described below was a qualified financing. Merger and Private Financing On March 6, 2015, the Company, Zeta Acquisition Corp. III, a public shell company (“Zeta”), and Kura Operations, Inc., a wholly-owned subsidiary of Zeta (“Merger Sub”), entered into an Agreement and Plan of Merger dated March 6, 2015 (the “Merger Agreement”). Pursuant to the Merger Agreement, Merger Sub merged with and into the Company, with the Company remaining as the surviving entity and a wholly-owned operating subsidiary of Zeta (the “Merger”). At the effective time of the Merger (the “Effective Time”), the name of the Company was changed to Kura Operations, Inc. Immediately following the Effective Time, a newly organized wholly-owned subsidiary of Zeta named “Kura Oncology, Inc.” merged with and into Zeta, with the surviving entity named Kura Oncology, Inc. (“Parent”). Pursuant to the terms of the Merger Agreement, at the Effective Time, each share of common stock of the Company outstanding immediately prior to the Effective Time was exchanged for one-half (0.5) of a share of common stock of Parent. Parent issued an aggregate of 14,508,177 shares of common stock upon such exchange of the issued shares of the Company common stock. In addition, at the Effective Time, Parent assumed the Company’s 2014 Plan. As of the Effective Time, there were no outstanding options to purchase shares of the Company common stock under the 2014 Plan. Immediately prior to the Merger, on March 6, 2015, the Company sold to investors 8,280,696 shares of its common stock at a price of $6.32 per share for gross proceeds of $52.3 million (the “New Money Financing”). The New Money Financing represented a qualified financing conversion event pursuant to the outstanding convertible promissory notes. As such, upon closing the New Money Financing, $7.5 million in principal and $115,000 in accrued interest through February 28, 2015 automatically converted into 1,204,870 shares of the Company’s common stock. The Company is considered the accounting acquirer in the Merger and will account for the transaction as a capital transaction because the Company’s stockholders received 100% of the voting rights in the combined entity and the Company’s senior management represents all of the senior management of the combined entity.

Business and Organization	6 Months Ended
Business and Organization	Jun. 30, 2015
Accounting Policies [Abstract]
Business and Organization	1. Business and Organization Kura Oncology, Inc., is a clinical stage biopharmaceutical company discovering and developing personalized therapeutics for the treatment of solid tumors and blood cancers. We focus on the development of small molecule drug candidates that target cell signaling pathways that are important to driving the progression of certain cancers. We aim to employ molecular diagnostics to identify patients with cancers who are likely to benefit from our targeted drug candidates. References in these Notes to Unaudited Condensed Financial Statements to the “Company” or “we”, “our” or “us”, refer to Kura Oncology, Inc., or Prior Kura, a private Delaware corporation incorporated in the State of Delaware in August 2014, for the periods prior to the Merger (as defined below) which took place on March 6, 2015, and Kura Oncology, Inc., a Delaware corporation incorporated in November 2007 and formerly known as Zeta Acquisition Corp. III, for the periods following the Merger. Effective March 6, 2015, or Effective Time, we completed a reverse merger, or the Merger, with a wholly owned subsidiary of “Zeta Acquisition Corp. III,” or Zeta, a public shell company, leaving Prior Kura as the surviving entity. On March 31, 2015, the surviving entity merged with and into us. Zeta was formed in November 2007 with no specific business plan or purpose. As a result of the Merger and related transactions, Zeta changed its name to “Kura Oncology, Inc.” and began operating Prior Kura’s business. Pursuant to the terms of the Merger Agreement, at the Effective Time, each share of Prior Kura common stock outstanding immediately prior to the Effective Time was exchanged for one-half (0.5) of a share of our common stock. The share and price per share amounts presented in these Unaudited Condensed Financial Statements have been adjusted for such exchange. We issued an aggregate of 14,508,177 shares of our common stock upon such exchange of the Prior Kura common stock outstanding. In addition, at the Effective Time, we assumed Prior Kura’s 2014 Equity Incentive Plan that was in existence immediately prior to the Effective Time and concurrently approved the amendment and restatement of the Prior Kura 2014 Equity Incentive Plan, or 2014 Plan, pursuant to our 2014 Plan, which became effective in April 2015. Refer to Note 12, Equity Incentive Plan for detailed discussion of the 2014 Plan. Immediately following the Effective Time, pursuant to the terms of a Redemption Agreement dated March 6, 2015, or the Redemption Agreement, by and among Zeta and its pre-Merger stockholders, we completed the closing of a redemption of 5,000,000 shares of our common stock, or the Redemption, from our pre-Merger stockholders for consideration of $70,000, plus $30,000 in professional fees related to the transaction. The 5,000,000 shares constituted all of the issued and outstanding shares of Zeta’s capital stock, on a fully-diluted basis, immediately prior to the Merger. Upon completion of the Merger and the Redemption, Prior Kura’s stockholders held 100% of the outstanding shares of our capital stock. Immediately prior to the Merger, on March 6, 2015, Prior Kura sold 8,280,696 shares of our common stock to investors at a price of $6.32 per share for gross proceeds of $52.3 million, or the Financing. The Financing represented a qualified financing conversion event pursuant to the then outstanding convertible promissory notes. As such, upon the closing of the Financing, $7.5 million in principal and $115,000 in accrued interest on such convertible promissory notes through February 28, 2015 automatically converted into 1,204,870 shares of our common stock. The Merger is accounted for as a reverse merger and a capital transaction. Prior Kura is the acquirer for accounting purposes and Zeta is the acquired company. Consequently, the assets and liabilities and the operations that are reflected in the historical financial statements prior to the Merger are those of Prior Kura and are recorded at Prior Kura’s historical cost basis. Prior Kura was incorporated in August 2014; therefore, there were no operations in the periods prior to August 2014. The financial statements after completion of the Merger include our assets, liabilities and operations. The historical equity accounts and awards of Prior Kura, including par value per share, share and per share numbers, have been retrospectively adjusted to reflect the one for 0.5 shares common stock exchange, the par value of $0.0001 and the number of shares received in the Merger.

Basis of Presentation	6 Months Ended
Basis of Presentation	Jun. 30, 2015
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Basis of Presentation	2. Basis of Presentation The accompanying unaudited condensed financial statements should be read in conjunction with Prior Kura’s audited financial statements and notes thereto for the year ended December 31, 2014 included elsewhere in this prospectus from which we derived our balance sheet as of December 31, 2014. The accompanying condensed financial statements have been prepared in accordance with U.S. generally accepted accounting principles, or GAAP, for interim financial information and with the instructions to Form 10-Q and Article 10 of Regulation S-X. Accordingly, since they are interim statements, the accompanying condensed financial statements do not include all of the information and notes required by GAAP for complete financial statements. The accompanying condensed financial statements reflect all adjustments, consisting of normal recurring adjustments, that are, in the opinion of our management, necessary to a fair statement of the results for the interim periods presented. Interim results are not necessarily indicative of results for a full year. The preparation of the condensed financial statements in accordance with GAAP requires our management to make estimates and assumptions that affect the amounts reported in our condensed financial statements and accompanying notes. The amounts reported could differ under different estimates and assumptions. On an ongoing basis, we evaluate our estimates and judgments, which are based on historical and anticipated results and trends and on various other assumptions that management believes to be reasonable under the circumstances. By their nature, estimates are subject to an inherent degree of uncertainty and, as such, actual results may differ from management’s estimates.

Short-Term Investments

6 Months Ended

Jun. 30, 2015

Investments, Debt and Equity Securities [Abstract]

Short-Term Investments

4. Short-Term Investments

The following table summarizes, by major security type, our short-term investments that are measured at fair value on a recurring basis as of June 30, 2015, in thousands:


		As of June 30, 2015
	Maturity (in years)	Amortized Cost		Unrealized Gains		Unrealized Losses			Fair Value
Government sponsored entities	2 years or less	$	13,317	$	1	$	(2	)	$	13,316
Corporate debt securities	2 years or less		8,946		—		(13	)		8,933
Commercial paper	1 year or less		3,896		—		—			3,896

Total		$	26,159	$	1	$	(15	)	$	26,145

These investments are classified as current assets, even though the stated maturity date may be one year or more beyond the current balance sheet date, which reflects management’s intention to use the proceeds from sales of these securities to fund our operations, as necessary. We review our investments to identify and evaluate investments that have an indication of possible other-than-temporary impairment. Factors considered in determining whether a loss is other-than-temporary include the length of time and extent to which fair value has been less than the cost basis, the financial condition and near-term prospects of the investee, and our intent and ability to hold the investment for a period of time sufficient to allow for any anticipated recovery in market value. As of June 30, 2015, we had not recognized any such impairment in our condensed financial statements.

- Definition

The entire disclosure for investments in certain debt and equity securities.

+ References + Details

Fair Value Measurements

6 Months Ended

Jun. 30, 2015

Fair Value Disclosures [Abstract]

Fair Value Measurements

5. Fair Value Measurements

Investment Securities

As of June 30, 2015, we had cash equivalents and short-term investments measured at fair value on a recurring basis. As of December 31, 2014, we did not have any cash equivalents or short-term investments measured at fair value on a recurring basis. The carrying amounts of our financial instruments, which include cash equivalents, prepaid expenses, accounts payable, accrued expenses and all related party amounts approximate their fair values as of June 30, 2015, primarily due to their short-term nature. Fair value estimates of these instruments are made at a specific point in time, based on relevant market information. These estimates may be subjective in nature and involve uncertainties and matters of significant judgment and therefore cannot be determined with precision.

Available-for-sale marketable securities consist of corporate debt securities, commercial paper and government sponsored entities and were measured at fair value using Level 2 inputs. We determine the fair value of Level 2 related securities with the aid of valuations provided by third parties using proprietary valuation models and analytical tools. These valuation models and analytical tools use market pricing or prices for similar instruments that are both objective and publicly available, including matrix pricing or reported trades, benchmark yields, broker/dealer quotes, issuer spreads, two-sided markets, benchmark securities, bids and/or offers. We validate the fair values of Level 2 financial instruments by comparing these fair values to a third-party pricing source. No transfers between levels have occurred during the periods presented.

The following table summarizes, by major security type, our cash equivalents and short-term investments that are measured at fair value on a recurring basis and are categorized using the fair value hierarchy as of June 30, 2015, in thousands:


	Fair Value Measurements at June 30, 2015
	Balance		Level 1		Level 2		Level 3
Cash equivalents:
Money market funds	$	18,753	$	18,753	$	—	$	—
Short-term investments:
Government sponsored entities		13,316		—		13,316		—
Corporate debt securities		8,933		—		8,933		—
Commercial paper		3,896		—		3,896		—

Total short-term investments		26,145		—		26,145		—

Total	$	44,898	$	18,753	$	26,145	$	—

Derivative Liability

Our license agreement with The Regents of the University of California San Francisco, or UCSF, which was amended in April 2015, provides for an indexed milestone payment upon the occurrence of a qualified financing and a subsequent initial public offering or a change of control event, as defined in the agreement. The indexed milestone was determined to qualify as an embedded derivative liability requiring an estimate of fair value. The UCSF derivative liability is measured at fair value (Level 3) on a recurring basis and is included in other long-term liabilities on the condensed balance sheets. No transfers between levels have occurred during the periods presented.

We estimate the fair value of our derivative liabilities at the time of issuance and subsequent remeasurement at each reporting date using a probability model that considers the probability of achieving the events that would trigger such liabilities and the estimated time period the liabilities would be outstanding. The estimates are based, in part, on subjective assumptions and could differ materially in the future. Changes to these assumptions can have a significant impact on the fair value of the derivative liabilities.

The following table provides a reconciliation of all liabilities measured at fair value using Level 3 significant unobservable inputs:


	Derivative Liabilities (In thousands)
Balance at December 31, 2014	$	196
Change in fair value(1)		307

Balance at June 30, 2015	$	503

(1)	The amount is included within research and development expenses on our condensed statement of operations and comprehensive loss. The change in fair value of the derivative liability for the three and six months ended June 30, 2015 was $210,000 and $307,000, respectively.

Equity Incentive Plan

6 Months Ended

Jun. 30, 2015

Disclosure of Compensation Related Costs, Share-based Payments [Abstract]

Equity Incentive Plan

12. Equity Incentive Plan

In August 2014, Prior Kura adopted the Prior Kura 2014 Equity Incentive Plan. In connection with the Merger as discussed in Note 1, at the Effective Time of the Merger, we adopted the Prior Kura 2014 Equity Incentive Plan and approved the amendment and restatement of the Prior Kura 2014 Equity Incentive Plan pursuant to the 2014 Plan, which became effective April 13, 2015. Under the 2014 Plan, a total of 5,975,000 shares are reserved for issuance. As of June 30, 2015, there were 621,500 shares of common stock reserved for future stock awards under the 2014 Plan. The 2014 Plan provides equity-based incentives in the form of stock awards to employees and other providers of services to us. The 2014 Plan provides for the grant of incentive stock options, non-statutory stock options, restricted stock awards, restricted stock unit awards, performance-based stock awards and other forms of equity compensation to eligible recipients. Recipients of incentive stock options shall be eligible to purchase shares of our common stock at an exercise price equal to no less than the estimated fair market value of such stock on the date of grant. The maximum term of options to be granted under the 2014 Plan is ten years.

Stock Options

The following is a summary of stock option activity for the six months ended June 30, 2015, in thousands (except per share data):


	Number of Shares		Weighted Average Exercise Price per Share
Balance at December 31, 2014		—
Granted		410	$	6.32

Balance at June 30, 2015		410	$	6.32

Exercisable at June 30, 2015		2	$	6.32

The weighted average assumptions used to estimate the fair value of stock options granted to employees in the six months ended June 30, 2015 using the Black-Scholes option pricing model were as follows:


	Six Months Ended June 30, 2015
Weighted average grant date fair value per share	$	4.02
Expected volatility		70.8	%
Expected term (in years)		6.00 - 6.08
Risk free interest rate		1.8	%
Expected dividend yield		—

In estimating fair value for stock options issued under the 2014 Plan, expected volatility was based on historical volatility of comparable publicly-traded companies because our common stock has not been publicly traded. Due to the lack of historical option exercise data, we estimated the expected term using the simplified method. The risk-free interest rates are based on the U.S. Treasury zero-coupon bonds with maturities similar to those of the expected term of the award being valued. The expected dividend yield of zero reflects that we have not paid cash dividends since inception and do not intend to pay cash dividends in the foreseeable future. We apply estimate forfeitures at the time of grant based on historical experience and revise our estimate in subsequent periods if actual forfeitures differ from those estimates.

Restricted Stock Awards

Restricted stock awards were granted at a price equal to the estimated fair market value on the date of grant. The restricted stock awards generally vest over four years from the original vesting date, with certain grants subject to one-year cliff vesting. The vesting provisions of individual awards may vary as approved by our Board of Directors. In connection with the issuance of restricted common stock, we maintain a repurchase right where shares of restricted common stock are released from such repurchase right over a period of time of continued service by the recipient. The repurchase price for unvested stock awards will be the lower of (i) the fair market value of the shares of common stock on the date of repurchase or (ii) their original purchase price. As of June 30, 2015, there were 3,899,285 shares subject to repurchase, of which 3,286,888 and 612,397 shares were related to employee and non-employee stock awards, respectively.

The following is a summary of restricted share activity for the six months ended June 30, 2015, in thousands (except per share data):


	Number of Shares			Weighted Average Grant Date Fair Value
Balance at December 31, 2014		4,533		$	0.002
Granted		—
Vested		(634	)

Unvested at June 30, 2015		3,899		$	0.003

Vested at June 30, 2015		1,044		$	0.004

For the six months ended June 30, 2015, 487,028 and 146,561 shares underlying restricted stock awards granted to employees and non-employees, respectively, vested. As of June 30, 2015, 809,112 and 235,103 shares of underlying restricted stock awards granted to employees and non-employees, respectively, were vested. For the three and six months ended June 30, 2015, we recognized share-based compensation expense related to restricted stock awards totaling $397,000 and $1.0 million, respectively, of which $364,000 and $968,000 related to non-employee restricted stock awards, respectively.

The following table summarizes share-based compensation expense for all equity awards granted, in thousands:


	Three months ended June 30, 2015		Six months ended June 30, 2015
Research and development	$	404	$	1,007
General and administrative		81		122

Total stock-based compensation expense	$	485	$	1,129

Summary of Significant Accounting Policies (Policies)

6 Months Ended

12 Months Ended

Jun. 30, 2015

Dec. 31, 2014

Accounting Policies [Abstract]

Use of Estimates

Use of Estimates

Concentration of Credit Risk

Concentration of Credit Risk

Property and Equipment

Property and Equipment

Property and equipment are stated at cost and depreciated using the straight-line method over the estimated useful lives of the assets which is three years for each asset class.

Impairment of Long-Lived Assets

Impairment of Long-Lived Assets

Convertible Notes and Derivative Accounting

Convertible Notes and Derivative Accounting

Deferred Rent

Deferred Rent

Research and Development Expenses

Research and Development Expenses

Research and Development Costs

Patent Costs

Patent Costs

Share-Based Payments

Share-Based Payments

Share-Based Compensation

Income Taxes

Income Taxes

Comprehensive Loss

Comprehensive Loss

Comprehensive loss is defined as the change in equity during the period from transactions and other events and non-owner sources, including unrealized losses on marketable securities.

Comprehensive Loss

Segment Reporting

Segment Reporting

Fair Value Measurements

Fair Value Measurements

•

Level 1 — Quoted prices (unadjusted) in active markets for identical assets or liabilities;

•

Level 2 — Inputs other than quoted prices included within Level 1 that are either directly or indirectly observable; and

•

Fair Value Measurements

•

Level 1- Quoted prices (unadjusted) in active markets for identical assets or liabilities;

•

Level 2- Inputs other than quoted prices included within Level 1 that are either directly or indirectly observable; and

•


			Fair Value Measurements at December 31, 2014
	Balance as of December 31, 2014		Quoted Prices in Active Markets for Identical Assets (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)
*Liabilities*
Embedded derivative liability(1)	$	196	$	—	$	—	$	196

(1)

The following table provides a reconciliation of all liabilities measured at fair value using Level 3 significant unobservable inputs, in thousands:


	Derivative Liabilities
Balance at August 22, 2014 (Inception)	$	—
Issuance of derivative liability(1)		196
Change in fair value(2)		—

Balance at December 31, 2014	$	196

(1)	The amount is included within research and development expenses on the Company’s Statement of Operations and Comprehensive Loss.

(2)	The license agreement was executed in November 2014 and no change in the valuation occurred between the execution date and December 31, 2014.

Net Loss per Share

Net Loss per Share

Cash and Cash Equivalents

Cash and Cash Equivalents

Short-Term Investments

Short-Term Investments

Clinical Trial Costs and Accruals

Clinical Trial Costs and Accruals

Recent Accounting Pronouncements

Recent Accounting Pronouncements

Summary of Significant Accounting Policies (Tables)

12 Months Ended

Dec. 31, 2014

Liabilities Measured at Fair Value on Recurring Basis

Liabilities measured at fair value on a recurring basis as of December 31, 2014 are as follows, in thousands:


			Fair Value Measurements at December 31, 2014
	Balance as of December 31, 2014		Quoted Prices in Active Markets for Identical Assets (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)
*Liabilities*
Embedded derivative liability(1)	$	196	$	—	$	—	$	196

(1)

Significant Unobservable Inputs (Level 3)

Liabilities Measured at Fair Value on Recurring Basis

The following table provides a reconciliation of all liabilities measured at fair value using Level 3 significant unobservable inputs, in thousands:


	Derivative Liabilities
Balance at August 22, 2014 (Inception)	$	—
Issuance of derivative liability(1)		196
Change in fair value(2)		—

Balance at December 31, 2014	$	196

(1)	The amount is included within research and development expenses on the Company’s Statement of Operations and Comprehensive Loss.

(2)	The license agreement was executed in November 2014 and no change in the valuation occurred between the execution date and December 31, 2014.

Property and equipment, net (Tables)

6 Months Ended

12 Months Ended

Jun. 30, 2015

Dec. 31, 2014

Property, Plant and Equipment [Abstract]

Property and Equipment

Property and equipment consisted of the following, in thousands:


	June 30, 2015			December 31, 2014
Computer equipment	$	59		$	26
Software		7			2

		66			28
Less: accumulated depreciation		(7	)		(1	)

Property and equipment, net	$	59		$	27

Property and equipment consisted of the following, in thousands:


	December 31, 2014
Computer equipment	$	26
Software		2

		28
Less: accumulated depreciation		(1	)

Property and equipment, net	$	27

Accounts Payable and Accrued Liabilities (Tables)

6 Months Ended

12 Months Ended

Jun. 30, 2015

Dec. 31, 2014

Payables and Accruals [Abstract]

Accounts Payable and Accrued Liabilities

Accounts payable and accrued liabilities consisted of the following, in thousands:


	June 30, 2015		December 31, 2014
Accounts payable	$	715	$	226
Accrued expenses		1,193		581
Accrued compensation and benefits		584		39

Total accounts payable and accrued expenses	$	2,492	$	846

Accounts payable and accrued liabilities consisted of the following, in thousands:


	December 31, 2014
Accounts payable	$	226
Accrued expenses		568
Accrued compensation and benefits		39

Total accounts payable and accrued expenses	$	833

Notes Payable (Tables)

12 Months Ended

Dec. 31, 2014

Debt Disclosure [Abstract]

Notes Payable and Unamortized Discount

Total notes payable and unamortized discount balances are as follows, in thousands:


	December 31, 2014
Face value of convertible notes	$	2,500
Accrued interest		36
Debt issuance costs associated with fair value of derivative		(7	)

Total	$	2,529
Less: current portion		(2,036	)

Total convertible notes, long-term	$	493

- Definition

Tabular disclosure of long-debt instruments or arrangements, including identification, terms, features, collateral requirements and other information necessary to a fair presentation. These are debt arrangements that originally required repayment more than twelve months after issuance or greater than the normal operating cycle of the entity, if longer.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.22)
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 3
-URI http://asc.fasb.org/extlink&oid=6928386&loc=d3e21475-112644

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 470
-Section 50
-Paragraph 3
-URI http://asc.fasb.org/extlink&oid=6479336&loc=d3e64711-112823

Reference 4: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 235
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08.(e),(f))
-URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e23780-122690

Reference 5: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 55
-Paragraph 8
-URI http://asc.fasb.org/extlink&oid=34725769&loc=d3e28878-108400

Reference 6: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 8
-URI http://asc.fasb.org/extlink&oid=6928386&loc=d3e21538-112644

Reference 7: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 6
-URI http://asc.fasb.org/extlink&oid=6928386&loc=d3e21506-112644

Reference 8: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 45
-Paragraph 1A
-URI http://asc.fasb.org/extlink&oid=6451184&loc=d3e28541-108399

Reference 9: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 45
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=6451184&loc=d3e28551-108399

Reference 10: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 7
-URI http://asc.fasb.org/extlink&oid=6928386&loc=d3e21521-112644

Reference 11: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Section 02
-Paragraph 22
-Article 5

+ Details

Commitments and Contingencies (Tables)

12 Months Ended

Dec. 31, 2014

Commitments and Contingencies Disclosure [Abstract]

Future Minimum Payments Required under Leases

Future minimum payments required under the leases as of December 31, 2014 are summarized as follows, in thousands:


Year Ending December 31,
2015	$	111
2016		88

Total minimum lease payments	$	199

Stockholders' Equity (Tables)

12 Months Ended

Dec. 31, 2014

Equity [Abstract]

Summary of Restricted Share Activity

The following is a summary of restricted share activity, in thousands, except per share data:


	Number of Shares			Weighted Average Grant Date Fair Value
Balance at August 22, 2014 (Inception)		—		$	—
Granted		4,944		$	0.002
Vested		(411	)

Unvested at December 31, 2014		4,533		$	0.002

Vested at December 31, 2014		411		$	0.002

Income Taxes (Tables)

12 Months Ended

Dec. 31, 2014

Income Tax Disclosure [Abstract]

Schedule of Effective Income Tax Rate Reconciliation

The Company’s effective income tax differs from the statutory federal rate of 34% at December 31, 2014 due to the following, in thousands:


	Period from August 22, 2014 (Inception) to December 31, 2014
Benefit for income taxes at statutory federal rate	$	(1,248	)
State income tax (benefit), net of federal benefit		(225	)
Share-based compensation		80
Research and development tax credits		(28	)
Other		13
Valuation allowance		1,408

Income tax expense	$	—

Components Of Deferred Tax Assets

Significant components of the Company’s deferred tax assets at December 31, 2014 are shown below, in thousands:


	December 31, 2014
Deferred tax assets
Intangibles	$	732
Net operating loss carryforwards		442
Research and development tax credit carryforwards		28
Accruals		205
Other		1

Total deferred tax assets		1,408
Less valuation allowance		(1,408	)

Net deferred tax assets	$	—

Short-Term Investments (Tables)

6 Months Ended

Jun. 30, 2015

Investments, Debt and Equity Securities [Abstract]

Short-Term Investments Measured at Fair Value on Recurring Basis

The following table summarizes, by major security type, our short-term investments that are measured at fair value on a recurring basis as of June 30, 2015, in thousands:


		As of June 30, 2015
	Maturity (in years)	Amortized Cost		Unrealized Gains		Unrealized Losses			Fair Value
Government sponsored entities	2 years or less	$	13,317	$	1	$	(2	)	$	13,316
Corporate debt securities	2 years or less		8,946		—		(13	)		8,933
Commercial paper	1 year or less		3,896		—		—			3,896

Total		$	26,159	$	1	$	(15	)	$	26,145

Fair Value Measurements (Tables)

6 Months Ended

Jun. 30, 2015

Fair Value Disclosures [Abstract]

Schedule Of Fair Value Measurements, By Major Security Type


	Fair Value Measurements at June 30, 2015
	Balance		Level 1		Level 2		Level 3
Cash equivalents:
Money market funds	$	18,753	$	18,753	$	—	$	—
Short-term investments:
Government sponsored entities		13,316		—		13,316		—
Corporate debt securities		8,933		—		8,933		—
Commercial paper		3,896		—		3,896		—

Total short-term investments		26,145		—		26,145		—

Total	$	44,898	$	18,753	$	26,145	$	—

Significant Impact of Changes in Assumptions on Fair Value of Derivative Liabilities

The following table provides a reconciliation of all liabilities measured at fair value using Level 3 significant unobservable inputs:


	Derivative Liabilities (In thousands)
Balance at December 31, 2014	$	196
Change in fair value(1)		307

Balance at June 30, 2015	$	503

(1)	The amount is included within research and development expenses on our condensed statement of operations and comprehensive loss. The change in fair value of the derivative liability for the three and six months ended June 30, 2015 was $210,000 and $307,000, respectively.

Equity Incentive Plan (Tables)

6 Months Ended

Jun. 30, 2015

Disclosure of Compensation Related Costs, Share-based Payments [Abstract]

Summary of Stock Option Activity

The following is a summary of stock option activity for the six months ended June 30, 2015, in thousands (except per share data):


	Number of Shares		Weighted Average Exercise Price per Share
Balance at December 31, 2014		—
Granted		410	$	6.32

Balance at June 30, 2015		410	$	6.32

Exercisable at June 30, 2015		2	$	6.32

Summary of Weighted Average Assumptions of Fair Value of Stock Options Under Black-Scholes Option Pricing Model


	Six Months Ended June 30, 2015
Weighted average grant date fair value per share	$	4.02
Expected volatility		70.8	%
Expected term (in years)		6.00 - 6.08
Risk free interest rate		1.8	%
Expected dividend yield		—

Summary of Restricted Share Activity

The following is a summary of restricted share activity for the six months ended June 30, 2015, in thousands (except per share data):


	Number of Shares			Weighted Average Grant Date Fair Value
Balance at December 31, 2014		4,533		$	0.002
Granted		—
Vested		(634	)

Unvested at June 30, 2015		3,899		$	0.003

Vested at June 30, 2015		1,044		$	0.004

Summary of Share-based Compensation Expense

The following table summarizes share-based compensation expense for all equity awards granted, in thousands:


	Three months ended June 30, 2015		Six months ended June 30, 2015
Research and development	$	404	$	1,007
General and administrative		81		122

Total stock-based compensation expense	$	485	$	1,129

Organization and Basis of Presentation - Additional Information (Detail) - USD ($) $ in Thousands	Jun. 30, 2015	Dec. 31, 2014
Organization And Basis Of Presentation [Abstract]
Accumulated deficit	$ (13,732)	$ (3,671)

Summary of Significant Accounting Policies - Additional Information (Detail)	4 Months Ended	6 Months Ended
	Dec. 31, 2014 USD ($) Segment shares	Jun. 30, 2015 Segment shares
Summary Of Significant Accounting Policies [Line Items]
Property and equipment, estimated useful life	3 years
Impairment losses on long-lived assets \| $	$ 0
Number of operating segments \| Segment	1	1
Potentially dilutive securities	4,532,874
Convertible Debt Securities
Summary Of Significant Accounting Policies [Line Items]
Principal of outstanding convertible promissory notes \| $	$ 2,500,000
Unvested Stock Awards
Summary Of Significant Accounting Policies [Line Items]
Potentially dilutive securities		3,899,285
Employee Stock Option
Summary Of Significant Accounting Policies [Line Items]
Potentially dilutive securities		410,000

Liabilities Measured at Fair Value on Recurring Basis (Detail) - Embedded derivative liability
$ in Thousands

Dec. 31, 2014

USD ($)

^[1]

Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]

Liabilities

$ 196

Level 1

Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]

Liabilities

Level 2

Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]

Liabilities

Significant Unobservable Inputs (Level 3)

Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]

Liabilities

$ 196

[1]

The Company's license agreement with the with The Regents of the University of California San Francisco ("UCSF"), further described in Note 7, provides for an indexed milestone payment upon the occurrence of a qualified preferred stock financing and a subsequent initial public offering or a change of control event, as defined in the agreement. The indexed milestone was determined to qualify as an embedded derivative liability requiring an estimate of fair value.

Summary of Significant Accounting Policies - Significant Impact of Changes in Assumptions on Fair Value of Derivative Liabilities (Detail) - USD ($)
$ in Thousands

3 Months Ended

4 Months Ended

6 Months Ended

Jun. 30, 2015

Dec. 31, 2014

Jun. 30, 2015

Fair Value Disclosures [Abstract]

Derivative Liabilities, Beginning Balance

$ 0

$ 196

Issuance of derivative liability

^[1]

196

Change in fair value

$ (210)

^[2]

(307)

^[3]

Derivative Liabilities, Ending Balance

$ 503

$ 196

$ 503

[1]	The amount is included within research and development expenses on the Company's Statement of Operations and Comprehensive Loss.
[2]	The license agreement was executed in November 2014 and no change in the valuation occurred between the execution date and December 31, 2014.
[3]	The amount is included within research and development expenses on our condensed statement of operations and comprehensive loss. The change in fair value of the derivative liability for the three and six months ended June 30, 2015 was $210,000 and $307,000, respectively.

Property and Equipment, Net (Detail) - USD ($) $ in Thousands	Jun. 30, 2015	Dec. 31, 2014
Property Plant And Equipment [Line Items]
Property and equipment, gross	$ 66	$ 28
Less: accumulated depreciation	(7)	(1)
Property and equipment, net	59	27
Computer Equipment
Property Plant And Equipment [Line Items]
Property and equipment, gross	59	26
Software
Property Plant And Equipment [Line Items]
Property and equipment, gross	$ 7	$ 2

Accounts Payable and Accrued Liabilities (Detail) - USD ($) $ in Thousands	Jun. 30, 2015	Dec. 31, 2014
Payables and Accruals [Abstract]
Accounts payable	$ 715	$ 226
Accrued expenses		568
Accrued expenses	1,193	581
Accrued compensation and benefits	584	39
Total accounts payable and accrued expenses		833
Total accounts payable and accrued expenses	$ 2,492	$ 846

Notes Payable - Additional Information (Detail) - USD ($)			12 Months Ended
	Dec. 23, 2014	Oct. 08, 2014	Dec. 31, 2014	Feb. 28, 2015	Jan. 31, 2015
January 2015 Convertible Notes
Debt Instrument [Line Items]
Convertible promissory note					$ 3,000,000
Unpaid principal and accrued interest converted into common stock shares				479,667
February 2015 Convertible Notes
Debt Instrument [Line Items]
Convertible promissory note				$ 1,000,000
Unpaid principal and accrued interest converted into common stock shares				158,852
Note Purchase Agreement and Convertible Promissory Note
Debt Instrument [Line Items]
Debt instrument maturity date, description			The earliest to occur of (i) December 31, 2015, (ii) upon a change in control, as defined in the agreement, or (iii) upon defined events of default.
Araxes Pharma LLC
Debt Instrument [Line Items]
Convertible promissory note		$ 2,000,000
Unpaid principal and accrued interest converted into common stock shares				326,443
Araxes Pharma LLC \| Note Purchase Agreement and Convertible Promissory Note \| Convertible Promissory Note
Debt Instrument [Line Items]
Interest rate		8.00%
Debt instrument maturity date, description		The earliest to occur of (i) December 31, 2015, (ii) upon a change in control, as defined in the agreement, or (iii) upon defined events of default.
Certain Officers and Certain Officer's Related Parties \| January 2015 Convertible Notes
Debt Instrument [Line Items]
Convertible promissory note					710,000
Araxes Asset Purchase Agreement
Debt Instrument [Line Items]
Convertible promissory note	$ 500,000
Unpaid principal and accrued interest converted into common stock shares				80,293
Araxes Asset Purchase Agreement \| Asset Purchase Agreement \| Convertible Promissory Note
Debt Instrument [Line Items]
Interest rate	8.00%
Debt instrument maturity date, description	The earliest to occur (i) of May 31, 2016 (ii) upon a change in control, as defined in the agreement, or (iii) upon defined events of default.
JJDC, Inc
Debt Instrument [Line Items]
Convertible promissory note					$ 1,000,000
Unpaid principal and accrued interest converted into common stock shares				159,615

Notes Payable and Unamortized Discount (Detail) $ in Thousands	Dec. 31, 2014 USD ($)
Debt Disclosure [Abstract]
Face value of convertible notes	$ 2,500
Accrued interest	36
Debt issuance costs associated with fair value of derivative	(7)
Total	2,529
Less: current portion	(2,036)
Total convertible notes, long-term	493
Total	$ 2,529

License and Asset Purchase Agreements - Additional Information (Detail) - USD ($)						3 Months Ended	4 Months Ended	6 Months Ended
	Feb. 15, 2015	Dec. 31, 2014	Dec. 23, 2014	Dec. 18, 2014	Nov. 21, 2014	Jun. 30, 2015	Dec. 31, 2014	Jun. 30, 2015
License Agreements [Line Items]
Convertible promissory note		$ 493,000					$ 493,000
Common stock, shares issued		4,944,000				14,508,177	4,944,000	14,508,177
Research and development						$ 3,345,000	$ 2,028,000	$ 5,949,000
Araxes Asset Purchase Agreement
License Agreements [Line Items]
Convertible promissory note			$ 500,000
Milestone payment to be received			9,700,000
Janssen License Agreement \| Up-front Payment Arrangement
License Agreements [Line Items]
Proceed from license agreement				$ 1,000,000
Asset Purchase Agreement \| Araxes Asset Purchase Agreement
License Agreements [Line Items]
Outstanding license agreements			8,500,000
Milestone payment to be received			$ 1,200,000
License Agreements
License Agreements [Line Items]
Outstanding license agreements					$ 81,700,000
License Agreements \| Up-front Payment Arrangement
License Agreements [Line Items]
Proceed from license agreement					1,100,000
License Agreements \| Initiation of Certain Development Activities
License Agreements [Line Items]
Outstanding license agreements		$ 1,200,000
License Agreements \| Specified Regulatory Approvals
License Agreements [Line Items]
Outstanding license agreements					30,500,000
License Agreements \| Specified Levels of Product Sales
License Agreements [Line Items]
Outstanding license agreements					$ 50,000,000
The University of Michigan License Agreement
License Agreements [Line Items]
License agreement date								Dec. 22, 2014
Common stock, shares issued						79,113		79,113
Research and development								$ 500,000
Agreement termination written notice								90 days
Agreement termination period due to payment failure								30 days
Agreement termination notice period in event of material breach								60 days
The University of Michigan Sponsored Research Agreement
License Agreements [Line Items]
Research and development						$ 251,000		$ 376,000
Sponsor of research over three- year	$ 2,700,000
Sponsored research agreement period	3 years
Sponsored research amount, expensed as incurred	$ 2,000,000

Commitments and Contingencies - Additional Information (Detail) - USD ($)			4 Months Ended	12 Months Ended
	Oct. 06, 2014	Aug. 29, 2014	Dec. 31, 2014	Dec. 31, 2014
Loss Contingencies [Line Items]
Rent expense			$ 27,000
Commitment to provide charitable contribution			$ 285,000	$ 285,000
Commitment to provide charitable contribution, description			The Company is obligated to make a charitable gift of $285,000 to the Leukemia and Lymphoma Society in connection with the Michigan agreement described in Note 7 to be paid in three equal parts the first part due in January 2015, the second part due in January 2016 and the final part due in January 2017. The full amount of the charitable gift has been accrued as of December 31, 2014.
MASSACHUSETTS \| Monthly
Loss Contingencies [Line Items]
Rent expense	$ 5,000
Araxes Pharma LLC
Loss Contingencies [Line Items]
Rent expense			$ 15,000
Percentage of rent escalation		3.00%
Sublease expiration date				Aug. 30, 2016
Araxes Pharma LLC \| Monthly
Loss Contingencies [Line Items]
Rent expense		$ 5,000		$ 5,000

Future Minimum Payments Required under Leases (Detail) $ in Thousands	Dec. 31, 2014 USD ($)
Leases [Abstract]
2015	$ 111
2016	88
Total minimum lease payments	$ 199

Stockholder's Equity - Additional Information (Detail) - USD ($)			4 Months Ended	6 Months Ended
	Mar. 06, 2015	Feb. 28, 2015	Dec. 31, 2014	Jun. 30, 2015	Apr. 13, 2015	Aug. 31, 2014
Stockholders' Equity Note [Abstract]
Common shares reserved for future issuance pursuant to future option grants			556,500
Convertible promissory notes outstanding			$ 2,529,000
Liability associated with shares issued with repurchase rights			$ 13,000
Shares subject to repurchase			4,532,874
Share-based compensation expense			$ 237,000	$ 1,129,000
Conversion of convertible promissory notes and accrued interest, Shares		1,204,870
Common stock, shares authorized			100,000,000	200,000,000	200,000,000
Common stock, par value			$ 0.0001	$ 0.0001	$ 0.0001
Preferred stock, shares authorized			10,000,000	10,000,000	10,000,000
Preferred stock, par value			$ 0.0001	$ 0.0001	$ 0.0001
2014 Plan
Stockholders' Equity Note [Abstract]
Shares reserved for issuance under the plan						5,500,000
Term of options to be granted under the Plan			10 years
Options granted under the plan			$ 0
Employee Restricted Shares
Stockholders' Equity Note [Abstract]
Restricted stock awards vesting period			4 years
Liability associated with shares issued with repurchase rights			$ 10,000
Shares granted			4,096,000
Weighted average price of shares			$ 0.002
Shares subject to repurchase			3,773,916
Shares of restricted stock awards vested			322,084	809,112
Non-Employee Restricted Stock
Stockholders' Equity Note [Abstract]
Restricted stock awards vesting period			4 years
Liability associated with shares issued with repurchase rights			$ 3,000
Shares granted			847,500
Shares subject to repurchase			758,958
Shares of restricted stock awards vested			88,542	235,103
Non Employee Awards
Stockholders' Equity Note [Abstract]
Share-based compensation expense			$ 237,000
Restricted Stock Awards
Stockholders' Equity Note [Abstract]
Shares granted			4,944,000
Weighted average price of shares			$ 0.002
Shares of restricted stock awards vested			411,000	634,000
Restricted Stock Awards \| 2014 Plan
Stockholders' Equity Note [Abstract]
Restricted stock awards vesting period			4 years
Restricted Stock Awards \| 2014 Plan \| Cliff Vesting period
Stockholders' Equity Note [Abstract]
Restricted stock awards vesting period			1 year
Convertible Debt Securities
Stockholders' Equity Note [Abstract]
Convertible promissory notes outstanding			$ 2,500,000
Research and development \| Non Employee Awards
Stockholders' Equity Note [Abstract]
Share-based compensation expense			233,000
General and administrative \| Non Employee Awards
Stockholders' Equity Note [Abstract]
Share-based compensation expense			$ 4,000
Private Placement
Stockholders' Equity Note [Abstract]
Common stock, shares issued	8,280,696
Common stock, issued price per share	$ 6.32
Proceeds from issuance of common stock net of issuance costs	$ 48,200,000
Financing fees	$ 4,100,000
Conversion of common stock		$ 7,500,000
Convertible promissory notes accrued interest		115,000
Payments for merger related costs		$ 568,000
Private Placement \| Common Stock
Stockholders' Equity Note [Abstract]
Conversion of convertible promissory notes and accrued interest, Shares		1,204,870

Stockholder's Equity - Summary of Restricted Share Activity (Detail) - Restricted Stock Awards - $ / shares	4 Months Ended	6 Months Ended
	Dec. 31, 2014	Jun. 30, 2015
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Beginning Balance, Number of Shares		4,533,000
Granted, Number of Shares	4,944,000
Vested, Number of Shares	(411,000)	(634,000)
Ending Balance, Number of Shares	4,533,000	3,899,000
Vested, Number of Shares	411,000	1,044,000
Beginning Balance, Weighted-Average Grant Date Fair Value		$ 0.002
Granted, Weighted-Average Grant Date Fair Value	$ 0.002
Ending Balance, Weighted-Average Grant Date Fair Value	0.002	0.004
Vested, Weighted-Average Grant Date Fair Value	$ 0.002	$ 0.003

Related Party Transactions - Additional Information (Detail) - USD ($)		3 Months Ended	4 Months Ended	6 Months Ended	12 Months Ended
	Aug. 29, 2014	Jun. 30, 2015	Dec. 31, 2014	Jun. 30, 2015	Dec. 31, 2014	Feb. 28, 2015	Jan. 31, 2015	Dec. 23, 2014	Oct. 08, 2014
Related Party Transaction [Line Items]
Rent expense			$ 27,000
January 2015 Convertible Notes
Related Party Transaction [Line Items]
Convertible promissory note							$ 3,000,000
Unpaid principal and accrued interest converted into common stock shares						479,667
Director
Related Party Transaction [Line Items]
Rent expense		$ 24,000		$ 49,000
Sublease expiration date				Aug. 30, 2016
Management service agreement, fixed				$ 100,000	$ 100,000
Management service agreement, full time equivalents performing collaboration services				350,000	$ 350,000
Office space sublease monthly rent				$ 5,000
Araxes Pharma LLC
Related Party Transaction [Line Items]
Convertible promissory note									$ 2,000,000
Rent expense			$ 15,000
Sublease expiration date					Aug. 30, 2016
Agreement expiration date				Dec. 31, 2015	Dec. 31, 2015
Agreement termination notice period				30 days	30 days
Management Fee, Description				We have a management services agreement with Araxes under which Araxes pays us a fixed $100,000 a month for management services. In addition, the agreement allows for Araxes to pay us an amount equal to the number of full time equivalents, or FTE, performing collaboration services for Araxes, at an annual FTE rate of $350,000, plus actual expenses as reasonably incurred. The agreement has an initial term expiring on December 31, 2015 and renews automatically for additional consecutive one-year periods. The agreement may be terminated by either party with a notice of at least 30 days prior to December 31, 2015 or the expiration of the then-renewal term.	The Company has a management services agreement with Araxes under which Araxes pays the Company a fixed $100,000 a month for management services. In addition, the agreement allows for Araxes to pay the Company an amount equal to the number of full time equivalents (“FTE”) performing collaboration services for Araxes, at an FTE rate of $350,000, plus actual expenses as reasonably incurred. The agreement has an initial term expiring on December 31, 2015 and renews automatically for additional consecutive one-year periods. The agreement may be terminated by either party with a notice of at least 30 days prior to December 31, 2015 or the expiration of the then-renewal term.
Research and development services expense at full time equivalents rate					$ 400,000
Unpaid principal and accrued interest converted into common stock shares						326,443
Araxes Pharma LLC \| Monthly
Related Party Transaction [Line Items]
Rent expense	$ 5,000				$ 5,000
Wellspring Biosciences LLC
Related Party Transaction [Line Items]
Agreement expiration date				Dec. 31, 2015
Agreement termination notice period				30 days
Research and development services expense at full time equivalents rate				$ 400,000
Certain Officers and Certain Officer's Related Parties \| January 2015 Convertible Notes
Related Party Transaction [Line Items]
Convertible promissory note							$ 710,000
Araxes Asset Purchase Agreement
Related Party Transaction [Line Items]
Convertible promissory note								$ 500,000
Unpaid principal and accrued interest converted into common stock shares						80,293

Income Taxes (Details Textual) (Detail)	12 Months Ended
Income Taxes (Details Textual) (Detail)	Dec. 31, 2014 USD ($)
IncomeTaxesTextualAbstract
Effective federal statutory income tax rate, Percent	34.00%
Loss carryforwards begin to expire	2034
Valuation allowance	$ 1,408,000
Income tax examination, likelihood of unfavorable settlement	An uncertain tax position will not be recognized if it has less than a 50% likelihood of being sustained.
Unrecognized tax benefits	$ 0
Unrecognized interest or penalties	0
Domestic Tax Authority
IncomeTaxesTextualAbstract
Net operating loss	1,100,000
Research credit carryforwards	$ 18,000
Credit carry forward begin to expire	2034
State and Local Jurisdiction
IncomeTaxesTextualAbstract
Net operating loss	$ 1,200,000
Research credit carryforwards	$ 16,000
Credit carry forward begin to expire	2029

Benefit from Income Tax (Detail) $ in Thousands	4 Months Ended
Benefit from Income Tax (Detail) $ in Thousands	Dec. 31, 2014 USD ($)
Income Tax Disclosure [Abstract]
Benefit for income taxes at statutory federal rate	$ (1,248)
State income tax (benefit), net of federal benefit	(225)
Share-based compensation	80
Research and development tax credits	(28)
Other	13
Valuation allowance	1,408
Income tax expense	$ 0

Income Taxes (Detail) $ in Thousands	Dec. 31, 2014 USD ($)
Deferred tax assets
Intangibles	$ 732
Net operating loss carryforwards	442
Research and development tax credit carryforwards	28
Accruals	205
Other	1
Total deferred tax assets	1,408
Less valuation allowance	(1,408)
Net deferred tax assets	$ 0

Subsequent Events - Additional Information (Detail)				4 Months Ended	6 Months Ended	12 Months Ended
Subsequent Events - Additional Information (Detail)	Aug. 13, 2015 USD ($) ft²	Mar. 06, 2015 USD ($) $ / shares shares	Feb. 15, 2015 USD ($)	Dec. 31, 2014 USD ($)	Jun. 30, 2015 USD ($)	Dec. 31, 2014	Feb. 11, 2015 USD ($)	Jan. 20, 2015 USD ($)	Jan. 12, 2015 USD ($)
Subsequent Event [Line Items]
Sale of stock, gross proceeds					$ 47,841,000
Rent payable over the lease period				$ 27,000
Note Purchase Agreement and Convertible Promissory Note
Subsequent Event [Line Items]
Convertible promissory note, maturity date description						The earliest to occur of (i) December 31, 2015, (ii) upon a change in control, as defined in the agreement, or (iii) upon defined events of default.
February 2015 Note Holders
Subsequent Event [Line Items]
Convertible promissory note, maturity date description						The earliest to occur of (i) December 31, 2015, (ii) upon a change in control, as defined in the agreement, or (iii) upon defined events of default.
Convertible Promissory Note \| Janssen License Agreement
Subsequent Event [Line Items]
Convertible promissory note, maturity date description						The earliest to occur of (i) May 31, 2016, (ii) upon a change in control, as defined in the agreement, or (iii) upon defined events of default.
Merger and Private Financing
Subsequent Event [Line Items]
Business acquisition, voting rights percentage acquired				100.00%		100.00%
Subsequent Event \| Note Purchase Agreement and Convertible Promissory Note
Subsequent Event [Line Items]
Convertible promissory note									$ 3,000,000
Convertible promissory note, interest rate									8.00%
Subsequent Event \| February 2015 Note Holders
Subsequent Event [Line Items]
Convertible promissory note							$ 1,000,000
Convertible promissory note, interest rate							8.00%
Subsequent Event \| Convertible Promissory Note \| Janssen License Agreement
Subsequent Event [Line Items]
Convertible promissory note								$ 1,000,000
Convertible promissory note, interest rate								8.00%
Subsequent Event \| Merger and Private Financing
Subsequent Event [Line Items]
Shares sold to investors \| shares		8,280,696
Shares sold to investors, share price \| $ / shares		$ 6.32
Sale of stock, gross proceeds		$ 52,300,000
Convertible promissory note, principal amount converted		7,500,000
Accrued interest converted		$ 115,000
Debt instrument conversion, shares issued \| shares		1,204,870
Subsequent Event \| Merger and Private Financing \| 2014 Plan
Subsequent Event [Line Items]
Options to purchase shares outstanding \| shares		0
Subsequent Event \| Merger and Private Financing \| Common Stock
Subsequent Event [Line Items]
Merger agreement, terms		Each share of common stock of the Company outstanding immediately prior to the Effective Time was exchanged for one-half (0.5) of a share of common stock of Parent.
Shares of the Company common stock issued upon exchange pursuant to merger agreement \| shares		14,508,177
Subsequent Event \| University of Michigan Sponsored Research Agreement
Subsequent Event [Line Items]
Sponsor of research over three- year			$ 2,700,000
Sponsored research agreement period			3 years
Sponsored research amount, expensed as incurred			$ 2,000,000
Cambridge Facilities Lease \| Subsequent Event
Subsequent Event [Line Items]
Operating lease, area of space \| ft²	3,677
Security deposit	$ 44,000
Lease term period	60 months
Office space sublease monthly rent	$ 21,000
Operating lease rate of increase in annual rent	1.40%
Rent payable over the lease period	$ 1,300,000

Business and Organization - Additional Information (Detail)			6 Months Ended
	Mar. 06, 2015 USD ($) $ / shares shares	Feb. 28, 2015 USD ($) shares	Jun. 30, 2015 USD ($) $ / shares shares	Apr. 13, 2015 $ / shares	Dec. 31, 2014 $ / shares shares
Organization and Financial Statements Disclosure [Line Items]
Common stock, shares issued \| shares			14,508,177		4,944,000
Redemption of pre merger common stock shares \| shares	5,000,000
Aggregate consideration of redemption	$ 70,000
Professional costs	$ 30,000
Percentage of capital stock held by prior Kura's stockholders upon completion of merger and redemption	100.00%
Proceeds from issuance of common stock, net			$ 47,841,000
Conversion of convertible promissory notes and accrued interest, Shares \| shares		1,204,870
Reverse merger common share exchange ratio			0.5
Common stock, par value \| $ / shares			$ 0.0001	$ 0.0001	$ 0.0001
Private Placement
Organization and Financial Statements Disclosure [Line Items]
Common stock, shares issued \| shares	8,280,696
Common stock, issued price per share \| $ / shares	$ 6.32
Proceeds from issuance of common stock, net	$ 52,300,000
Convertible promissory notes accrued interest		$ 115,000
Conversion of common stock		$ 7,500,000

Short-Term Investments - Short-Term Investments Measured at Fair Value on Recurring Basis (Detail) $ in Thousands	6 Months Ended
	Jun. 30, 2015 USD ($)
Schedule Of Available For Sale Securities [Line Items]
Amortized Cost	$ 26,159
Unrealized Gains	1
Unrealized Losses	(15)
Fair Value	$ 26,145
Government Sponsored Entities
Schedule Of Available For Sale Securities [Line Items]
Maturity (in years)	2 years or less
Amortized Cost	$ 13,317
Unrealized Gains	1
Unrealized Losses	(2)
Fair Value	$ 13,316
Corporate Debt Securities
Schedule Of Available For Sale Securities [Line Items]
Maturity (in years)	2 years or less
Amortized Cost	$ 8,946
Unrealized Losses	(13)
Fair Value	$ 8,933
Commercial Paper
Schedule Of Available For Sale Securities [Line Items]
Maturity (in years)	1 year or less
Amortized Cost	$ 3,896
Fair Value	$ 3,896

Fair Value Measurement - Fair Values of Investment Securities (Detail) $ in Thousands	Jun. 30, 2015 USD ($)
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Short-term investments	$ 26,145
Fair Value Measurements on Recurring Basis
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Short-term investments	26,145
Cash equivalents and short-term investments	44,898
Fair Value Measurements on Recurring Basis \| Level 1
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Cash equivalents and short-term investments	18,753
Fair Value Measurements on Recurring Basis \| Level 2
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Short-term investments	26,145
Cash equivalents and short-term investments	26,145
Fair Value Measurements on Recurring Basis \| Money Market Funds
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Cash equivalents	18,753
Fair Value Measurements on Recurring Basis \| Money Market Funds \| Level 1
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Cash equivalents	18,753
Fair Value Measurements on Recurring Basis \| Government Sponsored Entities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Short-term investments	13,316
Fair Value Measurements on Recurring Basis \| Government Sponsored Entities \| Level 2
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Short-term investments	13,316
Fair Value Measurements on Recurring Basis \| Corporate Debt Securities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Short-term investments	8,933
Fair Value Measurements on Recurring Basis \| Corporate Debt Securities \| Level 2
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Short-term investments	8,933
Fair Value Measurements on Recurring Basis \| Commercial Paper
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Short-term investments	3,896
Fair Value Measurements on Recurring Basis \| Commercial Paper \| Level 2
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Short-term investments	$ 3,896

Fair Value Measurement - Summary of Significant Impact of Changes in Assumptions on Fair Value of Derivative Liabilities (Detail) - USD ($)
$ in Thousands

3 Months Ended

4 Months Ended

6 Months Ended

Jun. 30, 2015

Dec. 31, 2014

Jun. 30, 2015

Fair Value Disclosures [Abstract]

Derivative Liabilities, Beginning Balance

$ 0

$ 196

Change in value of derivative liability

$ 210

^[1]

307

^[2]

Derivative Liabilities, Ending Balance

$ 503

$ 196

$ 503

[1]	The license agreement was executed in November 2014 and no change in the valuation occurred between the execution date and December 31, 2014.
[2]	The amount is included within research and development expenses on our condensed statement of operations and comprehensive loss. The change in fair value of the derivative liability for the three and six months ended June 30, 2015 was $210,000 and $307,000, respectively.

Fair Value Measurement - Summary of Significant Impact of Changes in Assumptions on Fair Value of Derivative Liabilities (Parenthetical) (Parenthetical) (Detail) - USD ($)
$ in Thousands

3 Months Ended

4 Months Ended

6 Months Ended

Jun. 30, 2015

Dec. 31, 2014

Jun. 30, 2015

Fair Value Disclosures [Abstract]

Change in fair value

$ (210)

$ 0

^[1]

$ (307)

^[2]

[1]	The license agreement was executed in November 2014 and no change in the valuation occurred between the execution date and December 31, 2014.
[2]	The amount is included within research and development expenses on our condensed statement of operations and comprehensive loss. The change in fair value of the derivative liability for the three and six months ended June 30, 2015 was $210,000 and $307,000, respectively.

Equity Incentive Plan - Additional Information (Detail) - USD ($)	3 Months Ended	4 Months Ended	6 Months Ended
	Jun. 30, 2015	Dec. 31, 2014	Jun. 30, 2015	Aug. 31, 2014
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Common shares reserved for future issuance pursuant to future option grants		556,500
Number of shares, subject to repurchase			3,899,285
Number of shares, subject to repurchase	3,899,000	4,533,000	3,899,000
Share-based compensation expense	$ 485,000		$ 1,129,000
Employee Restricted Shares
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Vesting period		4 years
Shares of restricted stock awards vested		322,084	809,112
Non-Employee Restricted Stock
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Vesting period		4 years
Shares of restricted stock awards vested		88,542	235,103
Share-based compensation expense	364,000		$ 968,000
Restricted Stock Awards
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Shares of restricted stock awards vested		411,000	634,000
Share-based compensation expense	$ 397,000		$ 1,000,000
Employee Stock Option
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of shares, subject to repurchase	3,286,888		3,286,888
Non Employee Awards
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of shares, subject to repurchase	612,397		612,397
Share-based Compensation Award, Tranche One \| Employee Restricted Shares
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Shares of restricted stock awards vested			487,028
Share-based Compensation Award, Tranche One \| Non-Employee Restricted Stock
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Shares of restricted stock awards vested			146,561
2014 Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Shares reserved for issuance				5,975,000
Common shares reserved for future issuance pursuant to future option grants	621,500		621,500
2014 Plan \| Restricted Stock Awards
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Vesting period	4 years
2014 Plan \| Restricted Stock With Cliff Vesting
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Vesting period	1 year
2014 Plan \| Maximum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Term of options to be granted under the Plan			10 years

Equity Incentive Plan - Summary of Stock Option Activity (Detail) - Employee Stock Option shares in Thousands	6 Months Ended
	Jun. 30, 2015 $ / shares shares
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Granted, Number of Shares \| shares	410
Ending Balance, Number of Shares \| shares	410
Exercisable, Number of Shares \| shares	2
Granted, Weighted-Average Exercise Price per Share \| $ / shares	$ 6.32
Ending Balance, Weighted-Average Exercise Price per Share \| $ / shares	6.32
Exercisable, Weighted-Average Exercise Price per Share \| $ / shares	$ 6.32

Equity Incentive Plan - Summary of Weighted Average Assumptions of Fair Value of Stock Options Under Black-Scholes Option Pricing Model (Detail)	6 Months Ended
	Jun. 30, 2015 $ / shares
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Weighted average grant date fair value per share	$ 4.02
Expected volatility	70.80%
Risk free interest rate	1.80%
Minimum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Expected term (in years)	6 years
Maximum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Expected term (in years)	6 years 29 days

Equity Incentive Plan - Summary of Share-based Compensation Expense (Detail) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
	Jun. 30, 2015	Jun. 30, 2015
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Share-based compensation expense	$ 485	$ 1,129
Research and development
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Share-based compensation expense	404	1,007
General and administrative
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Share-based compensation expense	$ 81	$ 122

Label	Element	Value
Stock Issued During Period, Value, Restricted Stock Award, Net of Forfeitures	us-gaap_StockIssuedDuringPeriodValueRestrictedStockAwardNetOfForfeitures	$ 1,000
Adjustments to Additional Paid in Capital, Share-based Compensation, Requisite Service Period Recognition	us-gaap_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue	237,000
Additional Paid-in Capital [Member]
Stock Issued During Period, Value, Restricted Stock Award, Net of Forfeitures	us-gaap_StockIssuedDuringPeriodValueRestrictedStockAwardNetOfForfeitures	1,000
Adjustments to Additional Paid in Capital, Share-based Compensation, Requisite Service Period Recognition	us-gaap_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue	$ 237,000
Common Stock [Member]
Stock Issued During Period, Shares, Restricted Stock Award, Net of Forfeitures	us-gaap_StockIssuedDuringPeriodSharesRestrictedStockAwardNetOfForfeitures	411,000
Retained Earnings [Member]
Net Income (Loss) Attributable to Parent	us-gaap_NetIncomeLoss	$ (3,671,000)

- Definition

The portion of profit or loss for the period, net of income taxes, which is attributable to the parent.

+ References + Details