0000950170-24-123363 | 10-Q | XBRL Viewer

Stockholders' Equity	9 Months Ended
Sep. 30, 2024
Equity [Abstract]
Stockholders' Equity	7. Stockholders’ Equity On January 26, 2024, we completed a private placement in which we sold to certain institutional accredited investors an aggregate of 1,376,813 shares of our common stock at a purchase price of $17.25 per share and pre-funded warrants to purchase up to an aggregate of 7,318,886 shares of common stock at a purchase price of $17.2499 per pre-funded warrant (representing the $17.25 per share purchase price less the exercise price of $0.0001 per warrant share), or the Private Placement. Net proceeds from the Private Placement, after deducting expenses, were approximately $145.8 million. The common stock and pre-funded warrants met the accounting standards guidance for equity classification, and proceeds were allocated between common stock and pre-funded warrant based on their relative fair value. As of September 30, 2024, pre-funded warrants to purchase 139,131 of such shares of common stock had been exercised and 7,179,755 remained outstanding. In June 2023, we completed a public offering in which we sold an aggregate of 5,660,871 shares of common stock at a price of $11.50 per share as well as pre-funded warrants to purchase 3,034,782 shares of our common stock at a price of $11.4999 per pre-funded warrant (representing the $11.50 per share purchase price less the exercise price of $0.0001 per warrant share). Net proceeds from the public offering, after deducting underwriting discounts and commissions and offering expenses, were approximately $93.6 million. As of September 30, 2024, pre-funded warrants to purchase 860,869 of such shares of common stock had been exercised and 2,173,913 remained outstanding. In November 2023, we entered into a Sales Agreement with Leerink Partners LLC and Cantor Fitzgerald & Co., or the ATM Facility, under which we may offer and sell, from time to time, at our sole discretion, shares of our common stock having an aggregate offering price of up to $150.0 million. We have not sold any shares of our common stock under the ATM Facility.

Stockholders' Equity

9 Months Ended

Sep. 30, 2024

7. Stockholders’ Equity

On January 26, 2024, we completed a private placement in which we sold to certain institutional accredited investors an aggregate of 1,376,813 shares of our common stock at a purchase price of $17.25 per share and pre-funded warrants to purchase up to an aggregate of 7,318,886 shares of common stock at a purchase price of $17.2499 per pre-funded warrant (representing the $17.25 per share purchase price less the exercise price of $0.0001 per warrant share), or the Private Placement. Net proceeds from the Private Placement, after deducting expenses, were approximately $145.8 million. The common stock and pre-funded warrants met the accounting standards guidance for equity classification, and proceeds were allocated between common stock and pre-funded warrant based on their relative fair value. As of September 30, 2024, pre-funded warrants to purchase 139,131 of such shares of common stock had been exercised and 7,179,755 remained outstanding.

In June 2023, we completed a public offering in which we sold an aggregate of 5,660,871 shares of common stock at a price of $11.50 per share as well as pre-funded warrants to purchase 3,034,782 shares of our common stock at a price of $11.4999 per pre-funded warrant (representing the $11.50 per share purchase price less the exercise price of $0.0001 per warrant share). Net proceeds from the public offering, after deducting underwriting discounts and commissions and offering expenses, were approximately $93.6 million. As of September 30, 2024, pre-funded warrants to purchase 860,869 of such shares of common stock had been exercised and 2,173,913 remained outstanding.

In November 2023, we entered into a Sales Agreement with Leerink Partners LLC and Cantor Fitzgerald & Co., or the ATM Facility, under which we may offer and sell, from time to time, at our sole discretion, shares of our common stock having an aggregate offering price of up to $150.0 million. We have not sold any shares of our common stock under the ATM Facility.

- Definition

The entire disclosure for equity.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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Reference 9: http://www.xbrl.org/2003/role/disclosureRef
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+ Details

Investments - Investments Measured at Fair Value on Recurring Basis (Detail) - USD ($) $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2024	Dec. 31, 2023
Schedule Of Available For Sale Securities [Line Items]
Short-term investments, Estimated Fair Value	$ 405,817	$ 386,639
Fair Value Measurements on Recurring Basis
Schedule Of Available For Sale Securities [Line Items]
Short-term investments, Amortized Cost		387,910
Short-term investments, Unrealized Gains		399
Short-term investments, Unrealized Losses		(1,670)
Short-term investments, Estimated Fair Value		386,639
Cash equivalents and Short-term investments, Amortized Cost	420,211	401,500
Cash equivalents and Short-term investments, Unrealized Gains	1,117	399
Cash equivalents and Short-term investments, Unrealized Losses	(1)	(1,670)
Cash equivalents and Short-term investments, Estimated Fair Value	421,327	400,229
Fair Value Measurements on Recurring Basis \| Money Market Funds
Schedule Of Available For Sale Securities [Line Items]
Cash equivalents, Amortized Cost	15,510	13,590
Cash equivalents, Estimated Fair Value	$ 15,510	$ 13,590
Fair Value Measurements on Recurring Basis \| Money Market Funds \| Maximum
Schedule Of Available For Sale Securities [Line Items]
Maturities (years)	1 year	1 year
Fair Value Measurements on Recurring Basis \| U.S. Treasury Securities
Schedule Of Available For Sale Securities [Line Items]
Short-term investments, Amortized Cost	$ 404,701	$ 300,388
Short-term investments, Unrealized Gains	1,117	395
Short-term investments, Unrealized Losses	(1)	(569)
Short-term investments, Estimated Fair Value	$ 405,817	$ 300,214
Fair Value Measurements on Recurring Basis \| U.S. Treasury Securities \| Maximum
Schedule Of Available For Sale Securities [Line Items]
Maturities (years)	2 years	2 years
Fair Value Measurements on Recurring Basis \| Corporate Debt Securities
Schedule Of Available For Sale Securities [Line Items]
Short-term investments, Amortized Cost		$ 64,591
Short-term investments, Unrealized Gains		4
Short-term investments, Unrealized Losses		(825)
Short-term investments, Estimated Fair Value		$ 63,770
Fair Value Measurements on Recurring Basis \| Corporate Debt Securities \| Maximum
Schedule Of Available For Sale Securities [Line Items]
Maturities (years)		2 years
Fair Value Measurements on Recurring Basis \| Non-U.S. government debt securities
Schedule Of Available For Sale Securities [Line Items]
Short-term investments, Amortized Cost		$ 15,000
Short-term investments, Unrealized Losses		(273)
Short-term investments, Estimated Fair Value		$ 14,727
Fair Value Measurements on Recurring Basis \| Non-U.S. government debt securities \| Maximum
Schedule Of Available For Sale Securities [Line Items]
Maturities (years)		1 year
Fair Value Measurements on Recurring Basis \| U.S. Agency Bonds
Schedule Of Available For Sale Securities [Line Items]
Short-term investments, Amortized Cost		$ 7,931
Short-term investments, Unrealized Losses		(3)
Short-term investments, Estimated Fair Value		$ 7,928
Fair Value Measurements on Recurring Basis \| U.S. Agency Bonds \| Maximum
Schedule Of Available For Sale Securities [Line Items]
Maturities (years)		1 year

Condensed Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023
Operating Activities
Net loss	$ (154,766)	$ (109,845)
Adjustments to reconcile net loss to net cash used in operating activities:
Share-based compensation expense	25,266	20,915
Amortization of premium and accretion of discounts on marketable securities, net	(10,256)	(6,687)
Depreciation expense	644	635
Non-cash interest expense	383	358
Changes in operating assets and liabilities:
Accounts payable and accrued expenses	2,498	2,681
Prepaid expenses and other current assets	632	574
Other long-term liabilities	523	75
Operating lease right-of-use and other long-term assets	262	778
Net cash used in operating activities	(134,814)	(90,516)
Investing Activities
Purchases of marketable securities	(418,465)	(310,135)
Maturities of marketable securities	411,930	283,649
Purchases of property and equipment	(100)	(152)
Net cash used in investing activities	(6,635)	(26,638)
Financing Activities
Proceeds from issuance of common stock and pre-funded warrants, net of offering costs	145,814	93,577
Proceeds from issuance of stock under equity plans	7,797	515
Net cash provided by financing activities	153,611	94,092
Net increase (decrease) in cash and cash equivalents	12,162	(23,062)
Cash and cash equivalents at beginning of period	37,318	51,802
Cash and cash equivalents at end of period	$ 49,480	$ 28,740

Leases (Tables)

9 Months Ended

Sep. 30, 2024

Leases [Abstract]

Schedule of Maturities of Lease Liabilities

Maturities of lease liabilities as of September 30, 2024 are as follows, in thousands:


Year Ending December 31,
2024 (remaining)	$	272
2025		1,964
2026		1,344
2027		1,371
2028		1,398
Thereafter		3,740
Total lease payments		10,089
Less: imputed interest		(2,932	)
Total operating lease liabilities	$	7,157

Investments (Tables)

9 Months Ended

Sep. 30, 2024

Investments, All Other Investments [Abstract]

Investments Measured at Fair Value on Recurring Basis

The following tables summarize, by major security type, our short-term investments that are measured at fair value on a recurring basis, in thousands:


		September 30, 2024
	Maturities (years)	Amortized Cost		Unrealized Gains		Unrealized Losses			Fair Value
Cash equivalents:
Money market funds	1 or less	$	15,510	$	—	$	—		$	15,510

Short-term investments:
U.S. Treasury securities	2 or less		404,701		1,117		(1	)		405,817
Total		$	420,211	$	1,117	$	(1	)	$	421,327


		December 31, 2023
	Maturities (years)	Amortized Cost		Unrealized Gains		Unrealized Losses			Fair Value
Cash equivalents:
Money market funds	1 or less	$	13,590	$	—	$	—		$	13,590

Short-term investments:
U.S. Treasury securities	2 or less		300,388		395		(569	)		300,214
Corporate debt securities	2 or less		64,591		4		(825	)		63,770
Non-U.S. government debt securities	1 or less		15,000		—		(273	)		14,727
U.S. Agency bonds	1 or less		7,931		—		(3	)		7,928
Total short-term investments			387,910		399		(1,670	)		386,639
Total		$	401,500	$	399	$	(1,670	)	$	400,229

- Definition

Tabular disclosure of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 320
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 9
-Subparagraph (a)
-Publisher FASB
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Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
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-Section 50
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-URI https://asc.fasb.org/1943274/2147481800/320-10-50-3

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-URI https://asc.fasb.org/1943274/2147481800/320-10-50-2

Reference 4: http://www.xbrl.org/2009/role/commonPracticeRef
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Reference 9: http://www.xbrl.org/2009/role/commonPracticeRef
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+ Details

Leases

9 Months Ended

Sep. 30, 2024

Leases [Abstract]

Leases

6. Leases

We currently have three operating leases for administrative and research and development office and lab space in San Diego, California and Boston, Massachusetts that expire between August 2025 and July 2031. Under the terms of the operating leases, we are required to pay our proportionate share of property taxes, insurance and normal maintenance costs. Two of our leases include renewal options for an additional five years, which were not included in the determination of the right of use, or ROU, asset or lease liability as the renewal was not reasonably certain at the inception of the lease. Our Boston lease, San Diego corporate headquarters lease, and San Diego lease for lab and office space provided for $1.3 million, $1.0 million and $0.1 million, respectively, in reimbursements for allowable tenant improvements and rent credits, which effectively reduced the total lease payments owed.

Maturities of lease liabilities as of September 30, 2024 are as follows, in thousands:


Year Ending December 31,
2024 (remaining)	$	272
2025		1,964
2026		1,344
2027		1,371
2028		1,398
Thereafter		3,740
Total lease payments		10,089
Less: imputed interest		(2,932	)
Total operating lease liabilities	$	7,157

As of September 30, 2024 and December 31, 2023, the weighted-average discount rate was 11.2% and 10.4%, respectively, and the weighted-average remaining lease term was 5.9 years and 6.2 years, respectively. Total cash paid for amounts included in the measurement of operating lease liabilities was $1.3 million and $1.7 million for the nine months ended September 30, 2024 and 2023, respectively. No operating lease ROU assets were obtained in exchange for operating lease liabilities for the nine months ended September 30, 2024 and 2023. Total operating lease expense for the three months ended September 30, 2024 and 2023 was approximately $0.5 million in both periods. Total operating lease expense for the nine months ended September 30, 2024 and 2023 was approximately $1.5 million in both periods.

Leases - Schedule of Maturities of Lease Liabilities (Detail) $ in Thousands	Sep. 30, 2024 USD ($)
Leases [Abstract]
2024 (remaining)	$ 272
2025	1,964
2026	1,344
2027	1,371
2028	1,398
Thereafter	3,740
Total lease payments	10,089
Less: imputed interest	(2,932)
Total operating lease liabilities	$ 7,157

Balance Sheet Detail - Summary of Property and Equipment (Detail) - USD ($) $ in Thousands	Sep. 30, 2024	Dec. 31, 2023
Property Plant And Equipment [Line Items]
Property and equipment, gross	$ 4,385	$ 4,311
Less: accumulated depreciation	(3,070)	(2,452)
Property and equipment, net	1,315	1,859
Laboratory and Computer Equipment
Property Plant And Equipment [Line Items]
Property and equipment, gross	1,632	1,657
Leasehold Improvements
Property Plant And Equipment [Line Items]
Property and equipment, gross	1,543	1,543
Furniture and Fixtures
Property Plant And Equipment [Line Items]
Property and equipment, gross	$ 1,210	$ 1,111

Organization and Basis of Presentation

9 Months Ended

Sep. 30, 2024

Organization, Consolidation and Presentation of Financial Statements [Abstract]

Organization and Basis of Presentation

1. Organization and Basis of Presentation

The Company

Kura Oncology, Inc. is a clinical-stage biopharmaceutical company committed to realizing the promise of precision medicines for the treatment of cancer. Our pipeline consists of small molecule product candidates that target cancer signaling pathways where there is a strong scientific and clinical rationale to improve outcomes, and we intend to pair them with molecular or cellular diagnostics to identify those patients most likely to respond to treatment. We are conducting clinical trials of three product candidates: ziftomenib, KO-2806 and tipifarnib. We also have additional programs that are at a discovery stage. We own global commercial rights to all of our programs and product candidates. We plan to advance our product candidates through a combination of internal development and strategic partnerships while maintaining significant development and commercial rights.

References in these Notes to Unaudited Condensed Financial Statements to the “Company,” “we,” “our” or “us,” refer to Kura Oncology, Inc.

Basis of Presentation

The accompanying unaudited condensed financial statements should be read in conjunction with the audited financial statements and notes thereto in our Annual Report on Form 10-K for the fiscal year ended December 31, 2023, as filed with the Securities and Exchange Commission on February 27, 2024, from which we derived our balance sheet as of December 31, 2023. The accompanying unaudited 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 unaudited condensed financial statements do not include all of the information and notes required by GAAP for complete financial statements. The accompanying unaudited 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 unaudited condensed financial statements in accordance with GAAP requires our management to make estimates and assumptions that affect the amounts reported on our unaudited 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.

Balance Sheet Detail - Summary of Current Accrued Expenses (Detail) - USD ($) $ in Thousands	Sep. 30, 2024	Dec. 31, 2023
Accrued Liabilities, Current [Abstract]
Accounts payable	$ 3,006	$ 2,300
Accrued compensation and benefits	12,482	13,153
Accrued clinical trial research and development expenses	10,950	7,737
Accrued other research and development expenses	8,060	9,265
Other accrued expenses	2,468	1,302
Total accounts payable and accrued expenses	$ 36,966	$ 33,757

Fair Value Measurements

9 Months Ended

Sep. 30, 2024

Fair Value Disclosures [Abstract]

Fair Value Measurements

4. Fair Value Measurements

As of September 30, 2024 and December 31, 2023, we had cash equivalents and short-term investments measured at fair value on a recurring basis.

Available-for-sale securities consist of money market funds and U.S. Treasury securities, which are measured at fair value using Level 1 inputs, and corporate debt securities, non-U.S. government debt securities, and U.S. Agency bonds which are 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.

The following tables summarize, 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, in thousands:


	September 30, 2024
	Total		Level 1		Level 2		Level 3
Cash equivalents:
Money market funds	$	15,510	$	15,510	$	—	$	—

Short-term investments:
U.S. Treasury securities		405,817		405,817		—		—
Total	$	421,327	$	421,327	$	—	$	—


	December 31, 2023
	Total		Level 1		Level 2		Level 3
Cash equivalents:
Money market funds	$	13,590	$	13,590	$	—	$	—

Short-term investments:
U.S. Treasury securities		300,214		300,214		—		—
Corporate debt securities		63,770	—			63,770		—
Non-U.S. government debt securities		14,727	—			14,727		—
U.S. Agency bonds		7,928	—			7,928		—
Total short-term investments		386,639		300,214		86,425		—
Total	$	400,229	$	313,804	$	86,425	$	—

We believe that our term loan facility bears interest at a rate that approximates prevailing market rates for instruments with similar characteristics and, accordingly, the carrying value of the term loan facility approximates fair value. The fair value of our term loan facility is determined using Level 2 inputs in the fair value hierarchy.

Stockholder's Equity - Additional Information (Detail) - USD ($)		1 Months Ended		9 Months Ended
	Jan. 26, 2024	Nov. 30, 2023	Jun. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Class of Stock [Line Items]
Common stock, shares issued	1,376,813		5,660,871
Common stock, issued purchase price per share	$ 17.25		$ 11.5
Net proceeds from the private placement, after deducting expenses	$ 145,800,000		$ 93,600,000	$ 145,814,000	$ 93,577,000
Private Placement Prefunded Warrants
Class of Stock [Line Items]
Common stock, issued purchase price per share	$ 17.25
Pre-funded warrants issued	7,318,886
Pre-funded warrants exercised				139,131
Pre-funded warrants issued price per warrants	$ 17.2499
Pre-funded warrants exercise price per share	$ 0.0001
Pre-funded warrants outstanding				7,179,755
Public Offering Prefunded Warrants
Class of Stock [Line Items]
Common stock, issued purchase price per share			$ 11.5
Pre-funded warrants issued			3,034,782
Pre-funded warrants exercised				860,869
Warrants issued to purchase of common stock			3,034,782
Warrants issued purchase price per warrants			$ 11.4999
Pre-funded warrants issued price per warrants			11.4999
Pre-funded warrants exercise price per share			$ 0.0001
Pre-funded warrants outstanding				2,173,913
Maximum \| Leerink Partners LLC and Cantor Fitzgerald and Co [Member] \| ATM Facility
Class of Stock [Line Items]
Aggregate offering price		$ 150,000,000

Share-Based Compensation (Tables)

9 Months Ended

Sep. 30, 2024

Share-Based Payment Arrangement [Abstract]

Summary of Share-based Compensation Expense

The following table summarizes share-based compensation expense for all share-based compensation arrangements, in thousands:


	Three Months Ended				Nine Months Ended
	September 30,				September 30,
	2024		2023		2024		2023
Research and development	$	3,570	$	3,223	$	11,218	$	9,430
General and administrative		4,754		3,867		14,048		11,485
Total share-based compensation expense	$	8,324	$	7,090	$	25,266	$	20,915

Condensed Balance Sheets (Unaudited) (Parenthetical) - $ / shares	Sep. 30, 2024	Dec. 31, 2023
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	200,000,000
Common stock, shares issued	77,749,000	74,350,000
Common stock, shares outstanding	77,749,000	74,350,000

Condensed Statements of Operations and Comprehensive Loss (Unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Operating Expenses:
Research and development	$ 41,705	$ 29,328	$ 117,700	$ 82,702
General and administrative	18,179	13,145	53,040	36,340
Total operating expenses	59,884	42,473	170,740	119,042
Other Income (Expense):
Interest and other income	5,892	4,275	17,190	10,352
Interest expense	(412)	(404)	(1,216)	(1,155)
Total other income, net	5,480	3,871	15,974	9,197
Net Loss	$ (54,404)	$ (38,602)	$ (154,766)	$ (109,845)
Net loss per share, basic	$ (0.63)	$ (0.5)	$ (1.8)	$ (1.53)
Net loss per share, diluted	$ (0.63)	$ (0.5)	$ (1.8)	$ (1.53)
Weighted average number of shares used in computing net loss per share, basic	86,950	77,241	85,834	71,845
Weighted average number of shares used in computing net loss per share, diluted	86,950	77,241	85,834	71,845
Comprehensive Loss:
Net loss	$ (54,404)	$ (38,602)	$ (154,766)	$ (109,845)
Other comprehensive income:
Unrealized gain on marketable securities	1,579	1,687	2,387	4,497
Comprehensive Loss	$ (52,825)	$ (36,915)	$ (152,379)	$ (105,348)

Share-Based Compensation - Additional Information (Detail) - USD ($) $ in Millions	1 Months Ended	9 Months Ended
	May 31, 2023	Sep. 30, 2024
Stock Option
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Unrecognized estimated stock option compensation expenses		$ 47.2
Weighted average period remaining for amortization of unrecognized compensation cost		2 years 7 months 6 days
Restricted Stock Units
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Unrecognized estimated restricted stock units compensation expenses		$ 12.8
Weighted average period remaining for amortization of unrecognized compensation cost		2 years 8 months 12 days
Performance Based Restricted Stock Units
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
PSUs Granted	1,313,100

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 718
-SubTopic 10
-Name Accounting Standards Codification
-Section 35
-Paragraph 1D
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480483/718-10-35-1D

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 718
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-Section 35
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-URI https://asc.fasb.org/1943274/2147480483/718-10-35-3

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 718
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-Name Accounting Standards Codification
-Section 50
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Reference 4: http://www.xbrl.org/2003/role/disclosureRef
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-Subparagraph (a)(2)
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Reference 5: http://www.xbrl.org/2003/role/disclosureRef
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Reference 7: http://www.xbrl.org/2003/role/disclosureRef
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Reference 8: http://www.xbrl.org/2003/role/disclosureRef
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Reference 9: http://www.xbrl.org/2003/role/disclosureRef
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Reference 12: http://www.xbrl.org/2003/role/disclosureRef
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Reference 13: http://www.xbrl.org/2003/role/disclosureRef
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+ Details

Document and Entity Information - shares	9 Months Ended
Document and Entity Information - shares	Sep. 30, 2024	Nov. 04, 2024
Cover [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Sep. 30, 2024
Document Fiscal Year Focus	2024
Document Fiscal Period Focus	Q3
Trading Symbol	KURA
Entity Registrant Name	KURA ONCOLOGY, INC.
Entity Central Index Key	0001422143
Entity Current Reporting Status	Yes
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Entity Shell Company	false
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Common Stock, Shares Outstanding		77,763,750
Entity File Number	001-37620
Entity Tax Identification Number	61-1547851
Entity Address, Address Line One	12730 High Bluff Drive
Entity Address, Address Line Two	Suite 400
Entity Address, City or Town	San Diego
Entity Address, State or Province	CA
Entity Address, Postal Zip Code	92130
City Area Code	858
Local Phone Number	500-8800
Entity Interactive Data Current	Yes
Title of 12(b) Security	Common Stock, par value $0.0001 per share
Security Exchange Name	NASDAQ
Entity Incorporation, State or Country Code	DE
Document Quarterly Report	true
Document Transition Report	false

Balance Sheet Detail (Tables)

9 Months Ended

Sep. 30, 2024

Balance Sheet Related Disclosures [Abstract]

Summary of Property and Equipment

Property and equipment consisted of the following, in thousands:


	September 30, 2024			December 31, 2023
Laboratory and computer equipment	$	1,632		$	1,657
Leasehold improvements		1,543			1,543
Furniture and fixtures		1,210			1,111
Property and equipment, gross		4,385			4,311
Less: accumulated depreciation		(3,070	)		(2,452	)
Property and equipment, net	$	1,315		$	1,859

Summary of Accounts Payable and Accrued Expenses

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


	September 30, 2024		December 31, 2023
Accounts payable	$	3,006	$	2,300
Accrued compensation and benefits		12,482		13,153
Accrued clinical trial research and development expenses		10,950		7,737
Accrued other research and development expenses		8,060		9,265
Other accrued expenses		2,468		1,302
Total accounts payable and accrued expenses	$	36,966	$	33,757

Share-Based Compensation

9 Months Ended

Sep. 30, 2024

Share-Based Payment Arrangement [Abstract]

Share-Based Compensation

8. Share-Based Compensation

The following table summarizes share-based compensation expense for all share-based compensation arrangements, in thousands:


	Three Months Ended				Nine Months Ended
	September 30,				September 30,
	2024		2023		2024		2023
Research and development	$	3,570	$	3,223	$	11,218	$	9,430
General and administrative		4,754		3,867		14,048		11,485
Total share-based compensation expense	$	8,324	$	7,090	$	25,266	$	20,915

As of September 30, 2024, unrecognized estimated compensation expense related to stock options and restricted stock units was approximately $47.2 million and $12.8 million, respectively, which is expected to be recognized over a weighted average period of approximately 2.6 years and 2.7 years for stock options and restricted stock units, respectively. In May 2023, we granted an aggregate of 1,313,100 performance-based restricted stock units, or PSUs, to certain executives. The PSUs vest in six equal tranches upon the achievement of certain milestones and service conditions. As of September 30, 2024, we determined that the vesting of the PSUs was not probable and have not included the PSUs in share-based compensation expense or unrecognized estimated compensation expense.

Summary of Significant Accounting Policies - Additional Information (Detail) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023
Summary Of Significant Accounting Policies [Line Items]
Employee retention credit recognized during period		$ 2.8
Employee retention credit receivable during period	$ 2.8
Total potentially dilutive securities	15,136,000	12,664,000

Pay vs Performance Disclosure - USD ($) $ in Thousands	3 Months Ended						9 Months Ended
Pay vs Performance Disclosure - USD ($) $ in Thousands	Sep. 30, 2024	Jun. 30, 2024	Mar. 31, 2024	Sep. 30, 2023	Jun. 30, 2023	Mar. 31, 2023	Sep. 30, 2024	Sep. 30, 2023
Pay vs Performance Disclosure
Net Income (Loss)	$ (54,404)	$ (50,837)	$ (49,525)	$ (38,602)	$ (37,174)	$ (34,069)	$ (154,766)	$ (109,845)

- Definition

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

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 6
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-URI https://asc.fasb.org/1943274/2147483443/250-10-50-6

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
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Reference 7: http://www.xbrl.org/2003/role/disclosureRef
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+ Details

Share-Based Compensation - Summary of Share-based Compensation Expense (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Share-based compensation expense	$ 8,324	$ 7,090	$ 25,266	$ 20,915
Research and development
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Share-based compensation expense	3,570	3,223	11,218	9,430
General and administrative
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Share-based compensation expense	$ 4,754	$ 3,867	$ 14,048	$ 11,485

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

+ Details

Condensed Balance Sheets (Unaudited) - USD ($) $ in Thousands	Sep. 30, 2024	Dec. 31, 2023
Current assets:
Cash and cash equivalents	$ 49,480	$ 37,318
Short-term investments	405,817	386,639
Prepaid expenses and other current assets	7,892	8,524
Total current assets	463,189	432,481
Property and equipment, net	1,315	1,859
Operating lease right-of-use assets	6,100	6,993
Other long-term assets	8,233	7,602
Total assets	478,837	448,935
Current liabilities:
Accounts payable and accrued expenses	36,966	33,757
Current operating lease liabilities	1,691	1,506
Current portion of long-term debt	1,715
Total current liabilities	40,372	35,263
Long-term debt, net	7,757	9,332
Long-term operating lease liabilities	5,466	6,362
Other long-term liabilities	1,471	705
Total liabilities	55,066	51,662
Stockholders' equity:
Preferred stock, $0.0001 par value; 10,000 shares authorized; no shares issued and outstanding
Common stock, $0.0001 par value; 200,000 shares authorized; 77,749 and 74,350 shares issued and outstanding as of September 30, 2024 and December 31, 2023, respectively	8	7
Additional paid-in capital	1,298,852	1,119,976
Accumulated other comprehensive income (loss)	1,116	(1,271)
Accumulated deficit	(876,205)	(721,439)
Total stockholders' equity	423,771	397,273
Total liabilities and stockholders' equity	$ 478,837	$ 448,935

Balance Sheet Detail

9 Months Ended

Sep. 30, 2024

Balance Sheet Related Disclosures [Abstract]

Balance Sheet Detail

5. Balance Sheet Detail

Property and equipment consisted of the following, in thousands:


	September 30, 2024			December 31, 2023
Laboratory and computer equipment	$	1,632		$	1,657
Leasehold improvements		1,543			1,543
Furniture and fixtures		1,210			1,111
Property and equipment, gross		4,385			4,311
Less: accumulated depreciation		(3,070	)		(2,452	)
Property and equipment, net	$	1,315		$	1,859

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


	September 30, 2024		December 31, 2023
Accounts payable	$	3,006	$	2,300
Accrued compensation and benefits		12,482		13,153
Accrued clinical trial research and development expenses		10,950		7,737
Accrued other research and development expenses		8,060		9,265
Other accrued expenses		2,468		1,302
Total accounts payable and accrued expenses	$	36,966	$	33,757

Fair Value Measurements - Schedule Of Fair Value Measurements, By Major Security Type (Detail) - USD ($) $ in Thousands	Sep. 30, 2024	Dec. 31, 2023
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Short-term investments	$ 405,817	$ 386,639
Fair Value Measurements on Recurring Basis
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Short-term investments		386,639
Cash equivalents and short-term investments	421,327	400,229
Fair Value Measurements on Recurring Basis \| Level 1
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Short-term investments		300,214
Cash equivalents and short-term investments	421,327	313,804
Fair Value Measurements on Recurring Basis \| Level 2
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Short-term investments		86,425
Cash equivalents and short-term investments		86,425
Fair Value Measurements on Recurring Basis \| Money Market Funds
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Cash equivalents	15,510	13,590
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	15,510	13,590
Fair Value Measurements on Recurring Basis \| U.S. Treasury Securities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Short-term investments	405,817	300,214
Fair Value Measurements on Recurring Basis \| U.S. Treasury Securities \| Level 1
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Short-term investments	$ 405,817	300,214
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		63,770
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		63,770
Fair Value Measurements on Recurring Basis \| Non-U.S. government debt securities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Short-term investments		14,727
Fair Value Measurements on Recurring Basis \| Non-U.S. government debt securities \| Level 2
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Short-term investments		14,727
Fair Value Measurements on Recurring Basis \| U S Agency Bonds
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Cash equivalents		7,928
Fair Value Measurements on Recurring Basis \| U S Agency Bonds \| Level 2
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Short-term investments		$ 7,928

Insider Trading Arrangements

3 Months Ended

Sep. 30, 2024

Trading Arrangements, by Individual

Material Terms of Trading Arrangement

During the three months ended September 30, 2024, certain of our officers adopted written plans for the purchase or sale of our securities as noted below:


			Trading Arrangement
	Action	Date	Rule 10b5-1*	Non-Rule 10b5-1**	Total Shares to be Sold	Expiration Date
Stephen Dale, M.D., Chief Medical Officer	Adoption	September 17, 2024	X		772,834, and RSU net shares	December 16, 2025
Brian Powl, Chief Commercial Officer	Adoption	September 18, 2024	X		113,977, and RSU net shares	December 18, 2025
Thomas Doyle, Senior Vice President, Finance and Accounting	Adoption	September 17, 2024	X		125,597	December 18, 2025

______________________

* Intended to satisfy the affirmative defense of Rule 10b5-1(c)

** Not intended to satisfy the affirmative defense of Rule 10b5-1(c)

In addition, our officers (as defined in Rule 16a-1(f) under the Exchange Act) have entered into sell-to-cover arrangements adopted pursuant to Rule 10b5-1 authorizing the pre-arranged sale of shares to satisfy our tax withholding obligations arising exclusively from the vesting of shares of restricted stock. The amount of shares to be sold to satisfy our tax withholding obligations under these arrangements is dependent on future events which cannot be known at this time, including the future trading price of our shares. The expiration date relating to these arrangements is dependent on future events which cannot be known at this time, including the final vesting date of the applicable shares of restricted stock and the officer’s termination of service.

Stephen Dale

Trading Arrangements, by Individual

Name

Stephen Dale

Title

M.D., Chief Medical Officer

Rule 10b5-1 Arrangement Adopted

true

Non-Rule 10b5-1 Arrangement Adopted

false

September 17, 2024

December 16, 2025

456 days

772,834

Trading Arrangements, by Individual

Name

Brian Powl

Title

Chief Commercial Officer

Rule 10b5-1 Arrangement Adopted

true

Non-Rule 10b5-1 Arrangement Adopted

false

September 18, 2024

December 18, 2025

457 days

113,977

Trading Arrangements, by Individual

Name

Thomas Doyle

Title

Senior Vice President, Finance and Accounting

Rule 10b5-1 Arrangement Adopted

true

Non-Rule 10b5-1 Arrangement Adopted

false

September 17, 2024

December 18, 2025

458 days

125,597

Investments - Additional Information (Detail) $ in Thousands	9 Months Ended
	Sep. 30, 2024 USD ($) Security	Dec. 31, 2023 USD ($)
Investments, All Other Investments [Abstract]
Short-term investments with maturities less than one year	$ 390,700	$ 336,600
Short-term investments with maturities between one to two years	$ 15,100	50,000
Short-term investments maturities, description	As of September 30, 2024 and December 31, 2023, short-term investments of $390.7 million and $336.6 million, respectively, had maturities less than one year, and short-term investments of $15.1 million and $50.0 million, respectively, had maturities between one to two years.
Allowance for credit losses	$ 0	0
Available for sale securities gross unrealized loss position	$ 4,900
Number of available-for-sale securities \| Security	1
Accrued interest receivable on available-for-sale securities	$ 1,900	$ 1,100

Fair Value Measurements (Tables)

9 Months Ended

Sep. 30, 2024

Fair Value Disclosures [Abstract]

Schedule Of Fair Value Measurements, By Major Security Type


	September 30, 2024
	Total		Level 1		Level 2		Level 3
Cash equivalents:
Money market funds	$	15,510	$	15,510	$	—	$	—

Short-term investments:
U.S. Treasury securities		405,817		405,817		—		—
Total	$	421,327	$	421,327	$	—	$	—


	December 31, 2023
	Total		Level 1		Level 2		Level 3
Cash equivalents:
Money market funds	$	13,590	$	13,590	$	—	$	—

Short-term investments:
U.S. Treasury securities		300,214		300,214		—		—
Corporate debt securities		63,770	—			63,770		—
Non-U.S. government debt securities		14,727	—			14,727		—
U.S. Agency bonds		7,928	—			7,928		—
Total short-term investments		386,639		300,214		86,425		—
Total	$	400,229	$	313,804	$	86,425	$	—

Leases - Additional Information (Detail)	3 Months Ended		9 Months Ended
Leases - Additional Information (Detail)	Sep. 30, 2024 USD ($) Lease	Sep. 30, 2023 USD ($)	Sep. 30, 2024 USD ($) Lease	Sep. 30, 2023 USD ($)	Dec. 31, 2023
Lessee Lease Description [Line Items]
Number of operating leases \| Lease	3		3
Lessee, operating lease, expiration period			We currently have three operating leases for administrative and research and development office and lab space in San Diego, California and Boston, Massachusetts that expire between August 2025 and July 2031.
Number of leases that include renewal option \| Lease	2		2
Lease agreement additional extended lease term	5 years		5 years
Weighted-average discount rate	11.20%		11.20%		10.40%
Weighted-average remaining lease term	5 years 10 months 24 days		5 years 10 months 24 days		6 years 2 months 12 days
Total cash paid for amounts included in the measurement of lease liabilities			$ 1,300,000	$ 1,700,000
ROU assets obtained in exchange for operating lease liabilities			0	0
ASC 842
Lessee Lease Description [Line Items]
Total operating lease	$ 500,000	$ 500,000	1,500,000	$ 1,500,000
San Diego Corporate Headquarters Lease
Lessee Lease Description [Line Items]
Reimbursements for tenant improvements			1,000,000
San Diego Lease for Lab and Office Space
Lessee Lease Description [Line Items]
Reimbursements for tenant improvements			100,000
Boston Lease
Lessee Lease Description [Line Items]
Reimbursements for tenant improvements and rent credits			$ 1,300,000

Condensed Statements of Stockholders' Equity (Unaudited) - USD ($) shares in Thousands, $ in Thousands	Total	Common Stock	Additional Paid- In Capital	Accumulated Other Comprehensive Income (Loss)	Accumulated Deficit
Beginning balance at Dec. 31, 2022	$ 420,278	$ 7	$ 997,111	$ (8,032)	$ (568,808)
Beginning balance (in shares) at Dec. 31, 2022		68,314
Share-based compensation expense	6,838		6,838
Issuance of common stock under equity plans (in shares)		125
Other comprehensive income	2,136			2,136
Net loss	(34,069)				(34,069)
Ending balance at Mar. 31, 2023	395,183	$ 7	1,003,949	(5,896)	(602,877)
Ending balance (in shares) at Mar. 31, 2023		68,439
Beginning balance at Dec. 31, 2022	420,278	$ 7	997,111	(8,032)	(568,808)
Beginning balance (in shares) at Dec. 31, 2022		68,314
Net loss	(109,845)
Ending balance at Sep. 30, 2023	429,937	$ 7	1,112,118	(3,535)	(678,653)
Ending balance (in shares) at Sep. 30, 2023		74,251
Beginning balance at Mar. 31, 2023	395,183	$ 7	1,003,949	(5,896)	(602,877)
Beginning balance (in shares) at Mar. 31, 2023		68,439
Issuance of pre-funded warrants to purchase common stock, net of offering costs	32,658		32,658
Issuance of common stock, net of offering costs	60,919		60,919
Issuance of common stock, net of offering costs, (in shares)		5,661
Share-based compensation expense	6,987		6,987
Issuance of common stock under equity plans	431		431
Issuance of common stock under equity plans (in shares)		43
Other comprehensive income	674			674
Net loss	(37,174)				(37,174)
Ending balance at Jun. 30, 2023	459,678	$ 7	1,104,944	(5,222)	(640,051)
Ending balance (in shares) at Jun. 30, 2023		74,143
Share-based compensation expense	7,090		7,090
Issuance of common stock under equity plans	84		84
Issuance of common stock under equity plans (in shares)		108
Other comprehensive income	1,687			1,687
Net loss	(38,602)				(38,602)
Ending balance at Sep. 30, 2023	429,937	$ 7	1,112,118	(3,535)	(678,653)
Ending balance (in shares) at Sep. 30, 2023		74,251
Beginning balance at Dec. 31, 2023	397,273	$ 7	1,119,976	(1,271)	(721,439)
Beginning balance (in shares) at Dec. 31, 2023		74,350
Issuance of pre-funded warrants to purchase common stock, net of offering costs	122,726		122,726
Issuance of common stock, net of offering costs	23,088	$ 1	23,087
Issuance of common stock, net of offering costs, (in shares)		1,377
Share-based compensation expense	8,512		8,512
Issuance of common stock under equity plans	2,555		2,555
Issuance of common stock under equity plans (in shares)		454
Other comprehensive income	455			455
Net loss	(49,525)				(49,525)
Ending balance at Mar. 31, 2024	505,084	$ 8	1,276,856	(816)	(770,964)
Ending balance (in shares) at Mar. 31, 2024		76,181
Beginning balance at Dec. 31, 2023	397,273	$ 7	1,119,976	(1,271)	(721,439)
Beginning balance (in shares) at Dec. 31, 2023		74,350
Net loss	(154,766)
Ending balance at Sep. 30, 2024	423,771	$ 8	1,298,852	1,116	(876,205)
Ending balance (in shares) at Sep. 30, 2024		77,749
Beginning balance at Mar. 31, 2024	505,084	$ 8	1,276,856	(816)	(770,964)
Beginning balance (in shares) at Mar. 31, 2024		76,181
Share-based compensation expense	8,430		8,430
Issuance of common stock under equity plans	3,040		3,040
Issuance of common stock under equity plans (in shares)		241
Other comprehensive income	353			353
Net loss	(50,837)				(50,837)
Ending balance at Jun. 30, 2024	466,070	$ 8	1,288,326	(463)	(821,801)
Ending balance (in shares) at Jun. 30, 2024		76,422
Exercise of pre-funded warrants		1,000
Share-based compensation expense	8,324		8,324
Issuance of common stock under equity plans	2,202		2,202
Issuance of common stock under equity plans (in shares)		327
Other comprehensive income	1,579			1,579
Net loss	(54,404)				(54,404)
Ending balance at Sep. 30, 2024	$ 423,771	$ 8	$ 1,298,852	$ 1,116	$ (876,205)
Ending balance (in shares) at Sep. 30, 2024		77,749

Summary of Significant Accounting Policies	9 Months Ended
Summary of Significant Accounting Policies	Sep. 30, 2024
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	2. Summary of Significant Accounting Policies Employee Retention Credit Under the Coronavirus Aid, Relief, and Economic Security Act of 2020, or CARES Act, we were eligible to claim the employee retention credit, which is a refundable tax credit against certain employment taxes. For the nine months ended September 30, 2023, we recognized $2.8 million of employee retention credits related to wages paid to our employees from July 2020 through September 2021 within operating expenses as a reduction to personnel costs in the unaudited condensed statements of operations and comprehensive loss. We filed for the credit with the Internal Revenue Service in the first quarter of 2023. As of September 30, 2024, an employee retention credit receivable of $2.8 million was included within prepaid expenses and other current assets on the unaudited condensed balance sheets. Allowance for Credit Losses For available-for-sale securities in an unrealized loss position, we first assess whether we intend to sell, or if it is more likely than not that we will be required to sell, the security before recovery of its amortized cost basis. If either of the criteria regarding intent or requirement to sell is met, the security’s amortized cost basis is written down to fair value through earnings. For available-for-sale securities that do not meet the aforementioned criteria, we evaluate whether the decline in fair value has resulted from credit losses or other factors. In making this assessment, we consider the severity of the impairment, any changes in interest rates, market conditions, changes to the underlying credit ratings and forecasted recovery, among other factors. The credit-related portion of unrealized losses, and any subsequent improvements, are recorded in interest and other income through an allowance account. Any impairment that has not been recorded through an allowance for credit losses is included in other comprehensive income on the unaudited condensed statements of operations and comprehensive loss. We elected the practical expedient to exclude the applicable accrued interest from both the fair value and amortized costs basis of our available-for-sale securities for purposes of identifying and measuring an impairment. Accrued interest receivable on available-for-sale securities is recorded in prepaid expenses and other current assets on our unaudited condensed balance sheets. Our accounting policy is to not measure an allowance for credit loss for accrued interest receivable and to write-off any uncollectible accrued interest receivable as a reversal of interest income in a timely manner, which we consider to be in the period in which we determine the accrued interest will not be collected by us. Concentration of Credit Risk Financial instruments that potentially subject us to significant concentrations of credit risk consist primarily of cash, cash equivalents and short-term investments. We maintain deposits in federally insured financial institutions in excess of federally insured limits. We have established guidelines to limit our exposure to credit risk by placing investments with high credit quality financial institutions, diversifying our investment portfolio and placing investments with maturities that maintain safety and liquidity. We periodically review and modify these guidelines to maximize trends in yields and interest rates without compromising safety and liquidity. Net Loss per Share Basic net loss per common share is calculated by dividing the net loss by the weighted-average number of common shares outstanding for the period, which includes the shares related to outstanding pre-funded warrants, but excludes other potential common stock equivalents. Pre-funded warrants are considered outstanding for the purposes of computing basic and diluted net loss per share because shares may be issued for little additional consideration, and are fully vested and exercisable. Diluted net loss per share is calculated by dividing net loss by the weighted-average number of common shares and common stock equivalents outstanding for the period. As we have reported net loss for the three and nine months ended September 30, 2024 and 2023, dilutive net loss per common share is the same as basic net loss per common share for those periods. Common stock equivalents outstanding are comprised of stock options, restricted stock units, performance-based restricted stock units, warrants and employee stock purchase plan rights and are only included in the calculation of diluted earnings per common share when net income is reported and their effect is dilutive. Common stock equivalents outstanding at September 30, 2024 and 2023 totaling approximately 15,136,000 and 12,664,000, respectively, were excluded from the computation of dilutive weighted-average shares outstanding because their effect would be anti-dilutive. Recent Accounting Pronouncements From time to time, new accounting pronouncements are issued by the Financial Accounting Standards Board or other standard setting bodies that we adopt as of the specified effective date. We have evaluated recently issued accounting pronouncements and, based on our preliminary assessment, we do not believe any will have a material impact on our unaudited condensed financial statements or related footnote disclosures.

Summary of Significant Accounting Policies (Policies)	9 Months Ended
Summary of Significant Accounting Policies (Policies)	Sep. 30, 2024
Accounting Policies [Abstract]
Employee Retention Credit	Employee Retention Credit Under the Coronavirus Aid, Relief, and Economic Security Act of 2020, or CARES Act, we were eligible to claim the employee retention credit, which is a refundable tax credit against certain employment taxes. For the nine months ended September 30, 2023, we recognized $2.8 million of employee retention credits related to wages paid to our employees from July 2020 through September 2021 within operating expenses as a reduction to personnel costs in the unaudited condensed statements of operations and comprehensive loss. We filed for the credit with the Internal Revenue Service in the first quarter of 2023. As of September 30, 2024, an employee retention credit receivable of $2.8 million was included within prepaid expenses and other current assets on the unaudited condensed balance sheets.
Allowance for Credit Losses on Available-for-Sale Debt Securities	Allowance for Credit Losses For available-for-sale securities in an unrealized loss position, we first assess whether we intend to sell, or if it is more likely than not that we will be required to sell, the security before recovery of its amortized cost basis. If either of the criteria regarding intent or requirement to sell is met, the security’s amortized cost basis is written down to fair value through earnings. For available-for-sale securities that do not meet the aforementioned criteria, we evaluate whether the decline in fair value has resulted from credit losses or other factors. In making this assessment, we consider the severity of the impairment, any changes in interest rates, market conditions, changes to the underlying credit ratings and forecasted recovery, among other factors. The credit-related portion of unrealized losses, and any subsequent improvements, are recorded in interest and other income through an allowance account. Any impairment that has not been recorded through an allowance for credit losses is included in other comprehensive income on the unaudited condensed statements of operations and comprehensive loss. We elected the practical expedient to exclude the applicable accrued interest from both the fair value and amortized costs basis of our available-for-sale securities for purposes of identifying and measuring an impairment. Accrued interest receivable on available-for-sale securities is recorded in prepaid expenses and other current assets on our unaudited condensed balance sheets. Our accounting policy is to not measure an allowance for credit loss for accrued interest receivable and to write-off any uncollectible accrued interest receivable as a reversal of interest income in a timely manner, which we consider to be in the period in which we determine the accrued interest will not be collected by us.
Concentration of Credit Risk	Concentration of Credit Risk Financial instruments that potentially subject us to significant concentrations of credit risk consist primarily of cash, cash equivalents and short-term investments. We maintain deposits in federally insured financial institutions in excess of federally insured limits. We have established guidelines to limit our exposure to credit risk by placing investments with high credit quality financial institutions, diversifying our investment portfolio and placing investments with maturities that maintain safety and liquidity. We periodically review and modify these guidelines to maximize trends in yields and interest rates without compromising safety and liquidity.
Net Loss per Share	Net Loss per Share Basic net loss per common share is calculated by dividing the net loss by the weighted-average number of common shares outstanding for the period, which includes the shares related to outstanding pre-funded warrants, but excludes other potential common stock equivalents. Pre-funded warrants are considered outstanding for the purposes of computing basic and diluted net loss per share because shares may be issued for little additional consideration, and are fully vested and exercisable. Diluted net loss per share is calculated by dividing net loss by the weighted-average number of common shares and common stock equivalents outstanding for the period. As we have reported net loss for the three and nine months ended September 30, 2024 and 2023, dilutive net loss per common share is the same as basic net loss per common share for those periods. Common stock equivalents outstanding are comprised of stock options, restricted stock units, performance-based restricted stock units, warrants and employee stock purchase plan rights and are only included in the calculation of diluted earnings per common share when net income is reported and their effect is dilutive. Common stock equivalents outstanding at September 30, 2024 and 2023 totaling approximately 15,136,000 and 12,664,000, respectively, were excluded from the computation of dilutive weighted-average shares outstanding because their effect would be anti-dilutive.
Recent Accounting Pronouncements	Recent Accounting Pronouncements From time to time, new accounting pronouncements are issued by the Financial Accounting Standards Board or other standard setting bodies that we adopt as of the specified effective date. We have evaluated recently issued accounting pronouncements and, based on our preliminary assessment, we do not believe any will have a material impact on our unaudited condensed financial statements or related footnote disclosures.

- Definition

Disclosure of accounting policy for credit loss on financial instrument measured at amortized cost basis, net investment in lease, off-balance sheet credit exposure, and available-for-sale debt security. Includes, but is not limited to, methodology used to estimate allowance for credit loss, how writeoff of uncollectible amount is recognized, and determination of past due status and nonaccrual status.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 326
-SubTopic 20
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SAB Topic 6.M.2.Q4)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147483530/326-20-S99-1

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 326
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 14
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479319/326-20-50-14

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 326
-SubTopic 20
-Name Accounting Standards Codification
-Section 30
-Paragraph 5A
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479391/326-20-30-5A

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Topic 326
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 3C
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479319/326-20-50-3C

Reference 5: http://www.xbrl.org/2003/role/disclosureRef
-Topic 326
-SubTopic 20
-Name Accounting Standards Codification
-Section 35
-Paragraph 8A
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479366/326-20-35-8A

Reference 6: http://www.xbrl.org/2003/role/disclosureRef
-Topic 326
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-Name Accounting Standards Codification
-Section 50
-Paragraph 3D
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479319/326-20-50-3D

Reference 7: http://www.xbrl.org/2003/role/disclosureRef
-Topic 326
-SubTopic 20
-Name Accounting Standards Codification
-Section 45
-Paragraph 5
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479344/326-20-45-5

Reference 8: http://www.xbrl.org/2003/role/disclosureRef
-Topic 326
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-Name Accounting Standards Codification
-Section 30
-Paragraph 1B
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479175/326-30-30-1B

Reference 9: http://www.xbrl.org/2003/role/disclosureRef
-Topic 326
-SubTopic 30
-Name Accounting Standards Codification
-Section 50
-Paragraph 3C
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479106/326-30-50-3C

Reference 10: http://www.xbrl.org/2003/role/disclosureRef
-Topic 326
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-Name Accounting Standards Codification
-Section 50
-Paragraph 3A
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479106/326-30-50-3A

Reference 11: http://www.xbrl.org/2003/role/disclosureRef
-Topic 326
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-Name Accounting Standards Codification
-Section 50
-Paragraph 3D
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479106/326-30-50-3D

Reference 12: http://www.xbrl.org/2003/role/disclosureRef
-Topic 326
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-Name Accounting Standards Codification
-Section 35
-Paragraph 13A
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479148/326-30-35-13A

Reference 13: http://www.xbrl.org/2003/role/disclosureRef
-Topic 326
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-Name Accounting Standards Codification
-Section 30
-Paragraph 4A
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479391/326-20-30-4A

Reference 14: http://www.xbrl.org/2003/role/disclosureRef
-Topic 326
-SubTopic 30
-Name Accounting Standards Codification
-Section 35
-Paragraph 7A
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479148/326-30-35-7A

Reference 15: http://www.xbrl.org/2003/role/disclosureRef
-Topic 326
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-Name Accounting Standards Codification
-Section 50
-Paragraph 21
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-URI https://asc.fasb.org/1943274/2147479319/326-20-50-21

Reference 16: http://www.xbrl.org/2003/role/disclosureRef
-Topic 326
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Reference 17: http://www.xbrl.org/2003/role/disclosureRef
-Topic 326
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-Topic 326
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-URI https://asc.fasb.org/1943274/2147479319/326-20-50-17

+ Details

Investments

9 Months Ended

Sep. 30, 2024

Investments, All Other Investments [Abstract]

Investments

3. Investments

We invest in available-for-sale securities consisting of U.S. Treasury securities, money market funds, corporate debt securities, non-U.S. government debt securities, and U.S. Agency bonds. Available-for-sale securities are classified as either cash and cash equivalents or short-term investments on our unaudited condensed balance sheets.

The following tables summarize, by major security type, our short-term investments that are measured at fair value on a recurring basis, in thousands:


		September 30, 2024
	Maturities (years)	Amortized Cost		Unrealized Gains		Unrealized Losses			Fair Value
Cash equivalents:
Money market funds	1 or less	$	15,510	$	—	$	—		$	15,510

Short-term investments:
U.S. Treasury securities	2 or less		404,701		1,117		(1	)		405,817
Total		$	420,211	$	1,117	$	(1	)	$	421,327


		December 31, 2023
	Maturities (years)	Amortized Cost		Unrealized Gains		Unrealized Losses			Fair Value
Cash equivalents:
Money market funds	1 or less	$	13,590	$	—	$	—		$	13,590

Short-term investments:
U.S. Treasury securities	2 or less		300,388		395		(569	)		300,214
Corporate debt securities	2 or less		64,591		4		(825	)		63,770
Non-U.S. government debt securities	1 or less		15,000		—		(273	)		14,727
U.S. Agency bonds	1 or less		7,931		—		(3	)		7,928
Total short-term investments			387,910		399		(1,670	)		386,639
Total		$	401,500	$	399	$	(1,670	)	$	400,229

Short-term 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. As of September 30, 2024 and December 31, 2023, short-term investments of $390.7 million and $336.6 million, respectively, had maturities less than one year, and short-term investments of $15.1 million and $50.0 million, respectively, had maturities between one to two years. We had no realized gains or losses for the nine months ended September 30, 2024 and 2023.

As of September 30, 2024, one available-for-sale security with a fair market value of $4.9 million was in a gross unrealized loss position, but it has not been in a continuous unrealized loss position for greater than 12 months. We do not intend to sell such available-for-sale security, and it is not more likely than not that we will be required to sell such security prior to recovery of its amortized cost basis. We have no allowance for credit losses as of September 30, 2024 and December 31, 2023. Unrealized gains and losses that are not credit-related are included in accumulated other comprehensive income (loss).

Accrued interest receivable on available-for-sale securities was $1.9 million and $1.1 million as of September 30, 2024 and December 31, 2023, respectively. We have not written off any accrued interest receivables for the nine months ended September 30, 2024 and 2023.