Kura Oncology (KURA) 10-Q 10 May 23 2023 Q1 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	3 Months Ended
	Mar. 31, 2023	May 04, 2023
Cover [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Mar. 31, 2023
Document Fiscal Year Focus	2023
Document Fiscal Period Focus	Q1
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		68,438,576
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

Condensed Balance Sheets (Unaud

Condensed Balance Sheets (Unaudited) - USD ($) $ in Thousands	Mar. 31, 2023	Dec. 31, 2022
Current assets:
Cash and cash equivalents	$ 27,059	$ 51,802
Short-term investments	378,841	386,183
Prepaid expenses and other current assets	10,550	8,441
Total current assets	416,450	446,426
Property and equipment, net	2,370	2,540
Restricted cash	210	210
Operating lease right-of-use assets	3,391	3,842
Other long-term assets	3,554	3,288
Total assets	425,975	456,306
Current liabilities:
Accounts payable and accrued expenses	16,901	21,739
Current operating lease liabilities	2,332	2,318
Total current liabilities	19,233	24,057
Long-term debt, net	9,200	9,158
Long-term operating lease liabilities	2,008	2,548
Other long-term liabilities	351	265
Total liabilities	30,792	36,028
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; 68,439 and 68,314 shares issued and outstanding as of March 31, 2023 and December 31, 2022, respectively	7	7
Additional paid-in capital	1,003,949	997,111
Accumulated other comprehensive loss	(5,896)	(8,032)
Accumulated deficit	(602,877)	(568,808)
Total stockholders'equity	395,183	420,278
Total liabilities and stockholders'equity	$ 425,975	$ 456,306

Condensed Balance Sheets (Una_2

Condensed Balance Sheets (Unaudited) (Parenthetical) - $ / shares	Mar. 31, 2023	Dec. 31, 2022
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	68,439,000	68,314,000
Common stock, shares outstanding	68,439,000	68,314,000

Condensed Statements of Operati

Condensed Statements of Operations and Comprehensive Loss (Unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Operating Expenses:
Research and development	$ 25,192	$ 20,913
General and administrative	11,374	11,869
Total operating expenses	36,566	32,782
Other Income (Expense):
Interest and other income, net	2,861	329
Interest expense	(364)
Total other income, net	2,497	329
Net Loss	$ (34,069)	$ (32,453)
Net loss per share, basic	$ (0.50)	$ (0.49)
Net loss per share, diluted	$ (0.50)	$ (0.49)
Weighted average number of shares used in computing net loss per share, basic	68,403	66,607
Weighted average number of shares used in computing net loss per share, diluted	68,403	66,607
Comprehensive Loss:
Net loss	$ (34,069)	$ (32,453)
Other comprehensive income (loss):
Unrealized gain (loss) on marketable securities and foreign currency	2,136	(4,859)
Comprehensive Loss	$ (31,933)	$ (37,312)

Condensed Statements of Stockho

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, 2021	$ 506,609	$ 7	$ 941,359	$ (1,789)	$ (432,968)
Beginning balance (in shares) at Dec. 31, 2021		66,572
Share-based compensation expense	6,650		6,650
Issuance of common stock under equity plans	303		303
Issuance of common stock under equity plans, shares		64
Other comprehensive income (loss)	(4,859)			(4,859)
Net loss	(32,453)				(32,453)
Ending balance at Mar. 31, 2022	476,250	$ 7	948,312	(6,648)	(465,421)
Ending balance (in shares) at Mar. 31, 2022		66,636
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, shares		125
Other comprehensive income (loss)	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

Condensed Statements of Cash Fl

Condensed Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Operating Activities
Net loss	$ (34,069)	$ (32,453)
Adjustments to reconcile net loss to net cash used in operating activities:
Share-based compensation expense	6,838	6,650
Amortization of premium and accretion of discounts on marketable securities, net	(1,687)	1,100
Depreciation expense	206	177
Non-cash interest expense	115
Changes in operating assets and liabilities:
Prepaid expenses and other current assets	(2,109)	(2,630)
Operating lease right-of-use and other long-term assets	185	105
Accounts payable and accrued expenses	(5,364)	(5,251)
Other long-term liabilities	13	121
Net cash used in operating activities	(35,872)	(32,181)
Investing Activities
Maturities of marketable securities	85,000	26,487
Purchases of marketable securities	(73,835)	(51,400)
Purchases of property and equipment	(36)	(49)
Net cash provided by (used in) investing activities	11,129	(24,962)
Financing Activities
Proceeds from issuance of stock under equity plans		303
Net cash provided by financing activities		303
Net decrease in cash, cash equivalents and restricted cash	(24,743)	(56,840)
Cash, cash equivalents and restricted cash at beginning of period	52,012	90,882
Cash, cash equivalents and restricted cash at end of period	$ 27,269	$ 34,042

Organization and Basis of Prese

Organization and Basis of Presentation	3 Months Ended
	Mar. 31, 2023
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 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, 2022, as filed with the Securities and Exchange Commission on February 23, 2023, from which we derived our balance sheet as of December 31, 2022. 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.

Summary of Significant Accounti

Summary of Significant Accounting Policies	3 Months Ended
	Mar. 31, 2023
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	2. Summary of Significant Accounting Policies Restricted Cash Under the terms of an office lease entered into in March 2020, we are required to maintain a standby letter of credit during the term of the lease. As of March 31, 2023 , restricted cash of $ 0.2 million was pledged as collateral for the letter of credit. The following table provides a reconciliation of cash, cash equivalents, and restricted cash reported within the unaudited condensed balance sheets that sum to the total of the amounts shown in the unaudited condensed statements of cash flows, in thousands: March 31, 2023 December 31, 2022 March 31, 2022 December 31, 2021 Cash and cash equivalents $ 27,059 $ 51,802 $ 33,832 $ 90,672 Restricted cash 210 210 210 210 Total $ 27,269 $ 52,012 $ 34,042 $ 90,882 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 income through an allowance account. Any impairment that has not been recorded through an allowance for credit losses is included in other comprehensive income (loss) 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 within 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. 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 three months ended March 31, 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 March 31, 2023, an employee retention credit receivable of $ 2.8 million was included within prepaid expenses and other current assets in the unaudited condensed balance sheets and we expect to receive such credit in the form of a cash payment during the second half of 2023. 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, 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 shares and common stock equivalents outstanding for the period determined using the treasury-stock method. As we have reported net loss for the three months ended March 31, 2023 and 2022, 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, 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 March 31, 2023 and 2022 totaling approxim ately 11,284,000 and 9,501,000 , 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.

Investments

Investments	3 Months Ended
	Mar. 31, 2023
Investments, All Other Investments [Abstract]
Investments	3. Investments We invest in available-for-sale securities consisting of money market funds, U.S. Treasury securities, corporate debt securities, commercial paper, U.S. Agency bonds and non-U.S. government and supranational debt securities. 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: March 31, 2023 Maturities Amortized Unrealized Unrealized Fair Value Cash equivalents: Money market funds 1 or less $ 26,719 $ — $ — $ 26,719 Short-term investments: U.S. Treasury securities 2 or less 166,018 25 ( 2,224 ) 163,819 Corporate debt securities 2 or less 106,668 20 ( 2,989 ) 103,699 Commercial paper 1 or less 63,003 — — 63,003 U.S. Agency bonds 1 or less 30,790 63 ( 69 ) 30,784 Non-U.S. government and supranational debt securities 2 or less 18,258 — ( 722 ) 17,536 Total short-term investments 384,737 108 ( 6,004 ) 378,841 Total $ 411,456 $ 108 $ ( 6,004 ) $ 405,560 December 31, 2022 Maturities Amortized Unrealized Unrealized Fair Value Cash equivalents: Money market funds 1 or less $ 37,878 $ — $ — $ 37,878 U.S. Agency bonds 1 or less 9,956 — — 9,956 Total cash equivalents 47,834 — — 47,834 Short-term investments: U.S. Treasury securities 2 or less 183,051 16 ( 3,018 ) 180,049 Corporate debt securities 2 or less 115,763 — ( 3,931 ) 111,832 Commercial paper 1 or less 52,941 — — 52,941 U.S. Agency bonds 1 or less 16,192 11 ( 160 ) 16,043 Non-U.S. government and supranational debt securities 2 or less 26,268 — ( 950 ) 25,318 Total short-term investments 394,215 27 ( 8,059 ) 386,183 Total $ 442,049 $ 27 $ ( 8,059 ) $ 434,017 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 March 31, 2023 and December 31, 2022 , short-term investments of $ 268.3 million and $ 274.3 million, respectively, had maturities less than one year, and short-term investments of $ 110.5 million and $ 111.9 million, respectively, had maturities between one to two years. We had no realized gains or losses for the three months ended March 31, 2023 and 2022. As of March 31, 2023, 26 av ailable-for-sale securities with a fair market value of $ 227.7 million w ere in gross unrealized loss po sitions, $ 152.7 million of wh ich were in a continuous unrealized loss position for greater than 12 months. We do not intend to sell these available-for-sale securities, and it is not more likely than not that we will be required to sell these securities prior to recovery of their amortized cost basis. Based on our review of these available-for-sale securities, the unrealized losses at March 31, 2023 were primarily due to changes in interest rates and not due to increased credit risks associated with specific securities. W e have no allowance for credit losses as of March 31, 2023 and December 31, 2022. Unrealized gains and losses that are not credit-related are included in accumulated other comprehensive loss. Accrued interest receivable on available-for-sale securities was $ 0.9 million as of March 31, 2023 and December 31, 2022. We have not written off any accrued interest receivables for the three months ended March 31, 2023 and 2022 .

Fair Value Measurements

Fair Value Measurements	3 Months Ended
	Mar. 31, 2023
Fair Value Disclosures [Abstract]
Fair Value Measurements	4. Fair Value Measurements As of March 31, 2023 and December 31, 2022, we had cash equivalents and short-term investments measured at fair value on a recurring basis. Available-for-sale securities consist of U.S. Treasury securities, which are measured at fair value using Level 1 inputs, and corporate debt securities, commercial paper, U.S. Agency bonds and non-U.S. government and supranational debt securities 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: March 31, 2023 Total Level 1 Level 2 Cash equivalents: Money market funds $ 26,719 $ 26,719 $ — Short-term investments: U.S. Treasury securities 163,819 163,819 — Corporate debt securities 103,699 — 103,699 Commercial paper 63,003 — 63,003 U.S. Agency bonds 30,784 — 30,784 Non-U.S. government and supranational debt securities 17,536 — 17,536 Total short-term investments 378,841 163,819 215,022 Total $ 405,560 $ 190,538 $ 215,022 December 31, 2022 Total Level 1 Level 2 Cash equivalents: Money market funds $ 37,878 $ 37,878 $ — U.S. Agency bonds 9,956 — 9,956 Total cash equivalents 47,834 37,878 9,956 Short-term investments: U.S. Treasury securities 180,049 180,049 — Corporate debt securities 111,832 — 111,832 Commercial paper 52,941 — 52,941 U.S. Agency bonds 16,043 — 16,043 Non-U.S. government and supranational debt securities 25,318 — 25,318 Total short-term investments 386,183 180,049 206,134 Total $ 434,017 $ 217,927 $ 216,090 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.

Balance Sheet Detail

Balance Sheet Detail	3 Months Ended
	Mar. 31, 2023
Balance Sheet Related Disclosures [Abstract]
Balance Sheet Detail	5. Balance Sheet Detail Property and equipment consisted of the following, in thousands: March 31, 2023 December 31, 2022 Laboratory and computer equipment $ 1,568 $ 1,568 Leasehold improvements 1,543 1,543 Furniture and fixtures 1,068 1,032 Property and equipment, gross 4,179 4,143 Less: accumulated depreciation ( 1,809 ) ( 1,603 ) Property and equipment, net $ 2,370 $ 2,540 Accounts payable and accrued expenses consisted of the following, in thousands: March 31, 2023 December 31, 2022 Accounts payable $ 3,291 $ 1,533 Accrued clinical trial research and development expenses 1,576 2,440 Accrued other research and development expenses 5,084 5,030 Accrued compensation and benefits 5,073 10,300 Other accrued expenses 1,877 2,436 Total accounts payable and accrued expenses $ 16,901 $ 21,739

Leases

Leases	3 Months Ended
	Mar. 31, 2023
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 July 2024 and November 2025. 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 San Diego corporate headquarters lease and our San Diego lease for lab and office space provided for $ 1.0 million and $ 0.1 million, respectively, in reimbursements for allowable tenant improvements, which effectively reduced the total lease payments owed. Under the terms of our office lease in Boston, we are required to maintain a standby letter of credit of approximately $ 0.2 million during the term of the lease. Maturities of lease liabilities as of March 31, 2023 are as follows, in thousands: Year Ending December 31, 2023 (remaining) $ 1,789 2024 1,863 2025 929 Total lease payments 4,581 Less: imputed interest ( 241 ) Total operating lease liabilities $ 4,340 As of March 31, 2023 and December 31, 2022, the weighted-average discoun t rate was 5.5 % f or both periods, and the weighted-average remaining lease term was 2.1 years and 2.3 years, respectively. Total cash paid for amounts included in the measurement of operating lease lia bilities was $ 0.6 million for both the three months ended March 31, 2023 and 2022 . There were no operating lease ROU assets obtained in exchange for operating lease liabilities for the three months ended March 31, 2023 and 2022. Total operating lease expense for the three months ended March 31, 2023 and 2022 was approximately $ 0.5 million in both periods.

Share-Based Compensation

Share-Based Compensation	3 Months Ended
	Mar. 31, 2023
Share-Based Payment Arrangement [Abstract]
Share-Based Compensation	. Share-Based Compensation The following table summarizes share-based compensation expense for all share-based compensation arrangements, in thousands: Three Months Ended March 31, 2023 2022 Research and development $ 3,073 $ 2,456 General and administrative 3,765 4,194 Total share-based compensation expense $ 6,838 $ 6,650 As of March 31, 2023, unrecognized estimated compensation expense related to stock options and restricted stock units was approximate ly $ 49.6 million and $ 14.3 million, resp ectively, which is expected to be recognized over a weighted average period of approxim ately 2.8 years f or both stock options and restricted stock units.

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	3 Months Ended
	Mar. 31, 2023
Accounting Policies [Abstract]
Restricted Cash	Restricted Cash Under the terms of an office lease entered into in March 2020, we are required to maintain a standby letter of credit during the term of the lease. As of March 31, 2023 , restricted cash of $ 0.2 million was pledged as collateral for the letter of credit. The following table provides a reconciliation of cash, cash equivalents, and restricted cash reported within the unaudited condensed balance sheets that sum to the total of the amounts shown in the unaudited condensed statements of cash flows, in thousands: March 31, 2023 December 31, 2022 March 31, 2022 December 31, 2021 Cash and cash equivalents $ 27,059 $ 51,802 $ 33,832 $ 90,672 Restricted cash 210 210 210 210 Total $ 27,269 $ 52,012 $ 34,042 $ 90,882
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 income through an allowance account. Any impairment that has not been recorded through an allowance for credit losses is included in other comprehensive income (loss) 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 within 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.
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 three months ended March 31, 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 March 31, 2023, an employee retention credit receivable of $ 2.8 million was included within prepaid expenses and other current assets in the unaudited condensed balance sheets and we expect to receive such credit in the form of a cash payment during the second half of 2023.
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, 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 shares and common stock equivalents outstanding for the period determined using the treasury-stock method. As we have reported net loss for the three months ended March 31, 2023 and 2022, 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, 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 March 31, 2023 and 2022 totaling approxim ately 11,284,000 and 9,501,000 , 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.

Summary of Significant Accoun_3

Summary of Significant Accounting Policies (Tables)	3 Months Ended
	Mar. 31, 2023
Accounting Policies [Abstract]
Schedule of Reconciliation of Cash, Cash Equivalents and Restricted Cash	The following table provides a reconciliation of cash, cash equivalents, and restricted cash reported within the unaudited condensed balance sheets that sum to the total of the amounts shown in the unaudited condensed statements of cash flows, in thousands: March 31, 2023 December 31, 2022 March 31, 2022 December 31, 2021 Cash and cash equivalents $ 27,059 $ 51,802 $ 33,832 $ 90,672 Restricted cash 210 210 210 210 Total $ 27,269 $ 52,012 $ 34,042 $ 90,882

Investments (Tables)

Investments (Tables)	3 Months Ended
	Mar. 31, 2023
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: March 31, 2023 Maturities Amortized Unrealized Unrealized Fair Value Cash equivalents: Money market funds 1 or less $ 26,719 $ — $ — $ 26,719 Short-term investments: U.S. Treasury securities 2 or less 166,018 25 ( 2,224 ) 163,819 Corporate debt securities 2 or less 106,668 20 ( 2,989 ) 103,699 Commercial paper 1 or less 63,003 — — 63,003 U.S. Agency bonds 1 or less 30,790 63 ( 69 ) 30,784 Non-U.S. government and supranational debt securities 2 or less 18,258 — ( 722 ) 17,536 Total short-term investments 384,737 108 ( 6,004 ) 378,841 Total $ 411,456 $ 108 $ ( 6,004 ) $ 405,560 December 31, 2022 Maturities Amortized Unrealized Unrealized Fair Value Cash equivalents: Money market funds 1 or less $ 37,878 $ — $ — $ 37,878 U.S. Agency bonds 1 or less 9,956 — — 9,956 Total cash equivalents 47,834 — — 47,834 Short-term investments: U.S. Treasury securities 2 or less 183,051 16 ( 3,018 ) 180,049 Corporate debt securities 2 or less 115,763 — ( 3,931 ) 111,832 Commercial paper 1 or less 52,941 — — 52,941 U.S. Agency bonds 1 or less 16,192 11 ( 160 ) 16,043 Non-U.S. government and supranational debt securities 2 or less 26,268 — ( 950 ) 25,318 Total short-term investments 394,215 27 ( 8,059 ) 386,183 Total $ 442,049 $ 27 $ ( 8,059 ) $ 434,017

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	3 Months Ended
	Mar. 31, 2023
Fair Value Disclosures [Abstract]
Schedule Of Fair Value Measurements, By Major Security Type	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: March 31, 2023 Total Level 1 Level 2 Cash equivalents: Money market funds $ 26,719 $ 26,719 $ — Short-term investments: U.S. Treasury securities 163,819 163,819 — Corporate debt securities 103,699 — 103,699 Commercial paper 63,003 — 63,003 U.S. Agency bonds 30,784 — 30,784 Non-U.S. government and supranational debt securities 17,536 — 17,536 Total short-term investments 378,841 163,819 215,022 Total $ 405,560 $ 190,538 $ 215,022 December 31, 2022 Total Level 1 Level 2 Cash equivalents: Money market funds $ 37,878 $ 37,878 $ — U.S. Agency bonds 9,956 — 9,956 Total cash equivalents 47,834 37,878 9,956 Short-term investments: U.S. Treasury securities 180,049 180,049 — Corporate debt securities 111,832 — 111,832 Commercial paper 52,941 — 52,941 U.S. Agency bonds 16,043 — 16,043 Non-U.S. government and supranational debt securities 25,318 — 25,318 Total short-term investments 386,183 180,049 206,134 Total $ 434,017 $ 217,927 $ 216,090

Balance Sheet Detail (Tables)

Balance Sheet Detail (Tables)	3 Months Ended
	Mar. 31, 2023
Balance Sheet Related Disclosures [Abstract]
Summary of Property and Equipment	Property and equipment consisted of the following, in thousands: March 31, 2023 December 31, 2022 Laboratory and computer equipment $ 1,568 $ 1,568 Leasehold improvements 1,543 1,543 Furniture and fixtures 1,068 1,032 Property and equipment, gross 4,179 4,143 Less: accumulated depreciation ( 1,809 ) ( 1,603 ) Property and equipment, net $ 2,370 $ 2,540
Summary of Accounts Payable and Accrued Expenses	Accounts payable and accrued expenses consisted of the following, in thousands: March 31, 2023 December 31, 2022 Accounts payable $ 3,291 $ 1,533 Accrued clinical trial research and development expenses 1,576 2,440 Accrued other research and development expenses 5,084 5,030 Accrued compensation and benefits 5,073 10,300 Other accrued expenses 1,877 2,436 Total accounts payable and accrued expenses $ 16,901 $ 21,739

Leases (Tables)

Leases (Tables)	3 Months Ended
	Mar. 31, 2023
Leases [Abstract]
Schedule of Maturities of Lease Liabilities	Maturities of lease liabilities as of March 31, 2023 are as follows, in thousands: Year Ending December 31, 2023 (remaining) $ 1,789 2024 1,863 2025 929 Total lease payments 4,581 Less: imputed interest ( 241 ) Total operating lease liabilities $ 4,340

Share-Based Compensation (Table

Share-Based Compensation (Tables)	3 Months Ended
	Mar. 31, 2023
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 March 31, 2023 2022 Research and development $ 3,073 $ 2,456 General and administrative 3,765 4,194 Total share-based compensation expense $ 6,838 $ 6,650

Summary of Significant Accoun_4

Summary of Significant Accounting Policies - Additional Information (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022	Dec. 31, 2022	Dec. 31, 2021
Summary Of Significant Accounting Policies [Line Items]
Restricted cash pledged as collateral	$ 210	$ 210	$ 210	$ 210
Employee retention credit recognized during period	2,800
Employee retention credit receivable during period	$ 2,800
Total potentially dilutive securities	11,284,000	9,501,000
Collateral Pledged
Summary Of Significant Accounting Policies [Line Items]
Restricted cash pledged as collateral	$ 200

Summary of Significant Accoun_5

Summary of Significant Accounting Policies - Schedule of Reconciliation of Cash, Cash Equivalents and Restricted Cash (Details) - USD ($) $ in Thousands	Mar. 31, 2023	Dec. 31, 2022	Mar. 31, 2022	Dec. 31, 2021
Accounting Policies [Abstract]
Cash and cash equivalents	$ 27,059	$ 51,802	$ 33,832	$ 90,672
Restricted cash	210	210	210	210
Total	$ 27,269	$ 52,012	$ 34,042	$ 90,882

Investments - Investments Measu

Investments - Investments Measured at Fair Value on Recurring Basis (Detail) - USD ($) $ in Thousands	Mar. 31, 2023	Dec. 31, 2022
Schedule Of Available For Sale Securities [Line Items]
Short-term investments, Fair Value	$ 378,841	$ 386,183
Fair Value Measurements on Recurring Basis
Schedule Of Available For Sale Securities [Line Items]
Cash equivalents, Amortized Cost		47,834
Cash equivalents, Fair Value		47,834
Short-term investments, Amortized Cost	384,737	394,215
Short-term investments, Unrealized Gains	108	27
Short-term investments, Unrealized Losses	(6,004)	(8,059)
Short-term investments, Fair Value	378,841	386,183
Cash equivalents and Short-term investments, Amortized Cost	411,456	442,049
Cash equivalents and Short-term investments, Unrealized Gains	108	27
Cash equivalents and Short-term investments, Unrealized Losses	(6,004)	(8,059)
Cash equivalents and Short-term investments, Estimated Fair Value	405,560	434,017
Fair Value Measurements on Recurring Basis | Money Market Funds
Schedule Of Available For Sale Securities [Line Items]
Cash equivalents, Amortized Cost	26,719	37,878
Cash equivalents, Fair Value	$ 26,719	$ 37,878
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	$ 166,018	$ 183,051
Short-term investments, Unrealized Gains	25	16
Short-term investments, Unrealized Losses	(2,224)	(3,018)
Short-term investments, Fair Value	$ 163,819	$ 180,049
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	$ 106,668	$ 115,763
Short-term investments, Unrealized Gains	20
Short-term investments, Unrealized Losses	(2,989)	(3,931)
Short-term investments, Fair Value	$ 103,699	$ 111,832
Fair Value Measurements on Recurring Basis | Corporate Debt Securities | Maximum
Schedule Of Available For Sale Securities [Line Items]
Maturities (years)	2 years	2 years
Fair Value Measurements on Recurring Basis | Commercial Paper
Schedule Of Available For Sale Securities [Line Items]
Short-term investments, Amortized Cost	$ 63,003	$ 52,941
Short-term investments, Fair Value	$ 63,003	$ 52,941
Fair Value Measurements on Recurring Basis | Commercial Paper | Maximum
Schedule Of Available For Sale Securities [Line Items]
Maturities (years)	1 year	1 year
Fair Value Measurements on Recurring Basis | U.S. Agency Bonds
Schedule Of Available For Sale Securities [Line Items]
Cash equivalents, Amortized Cost		$ 9,956
Cash equivalents, Fair Value		9,956
Short-term investments, Amortized Cost	$ 30,790	16,192
Short-term investments, Unrealized Gains	63	11
Short-term investments, Unrealized Losses	(69)	(160)
Short-term investments, Fair Value	$ 30,784	$ 16,043
Fair Value Measurements on Recurring Basis | U.S. Agency Bonds | Maximum
Schedule Of Available For Sale Securities [Line Items]
Maturities (years)		1 year
Maturities (years)	1 year	1 year
Fair Value Measurements on Recurring Basis | Non U S Government And Supranational Debt Securities
Schedule Of Available For Sale Securities [Line Items]
Short-term investments, Amortized Cost	$ 18,258	$ 26,268
Short-term investments, Unrealized Losses	(722)	(950)
Short-term investments, Fair Value	$ 17,536	$ 25,318
Fair Value Measurements on Recurring Basis | Non U S Government And Supranational Debt Securities | Maximum
Schedule Of Available For Sale Securities [Line Items]
Maturities (years)	2 years	2 years

Investments - Additional Inform

Investments - Additional Information (Detail) $ in Thousands	3 Months Ended
	Mar. 31, 2023 USD ($) Security	Dec. 31, 2022 USD ($)
Investments, All Other Investments [Abstract]
Short-term investments with maturities less than one year	$ 268,300	$ 274,300
Short-term investments with maturities between one and two years	$ 110,500	111,900
Short-term investments maturities, description	As of March 31, 2023 and December 31, 2022, short-term investments of $268.3 million and $274.3 million, respectively, had maturities less than one year, and short-term investments of $110.5 million and $111.9 million, respectively, had maturities between one to two years.
Allowance for credit losses	$ 0	0
Available for sale securities gross unrealized loss positions	227,700
Available for sale securities gross unrealized loss positions greater than 12 months	$ 152,700
Number of available-for-sale securities | Security	26
Accrued interest receivable on available-for-sale securities	$ 900	$ 900

Fair Value Measurements - Sched

Fair Value Measurements - Schedule Of Fair Value Measurements, By Major Security Type (Detail) - USD ($) $ in Thousands	Mar. 31, 2023	Dec. 31, 2022
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Short-term investments	$ 378,841	$ 386,183
Fair Value Measurements on Recurring Basis
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Cash equivalents		47,834
Short-term investments	378,841	386,183
Cash equivalents and short-term investments	405,560	434,017
Fair Value Measurements on Recurring Basis | Level 1
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Cash equivalents		37,878
Short-term investments	163,819	180,049
Cash equivalents and short-term investments	190,538	217,927
Fair Value Measurements on Recurring Basis | Level 2
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Cash equivalents		9,956
Short-term investments	215,022	206,134
Cash equivalents and short-term investments	215,022	216,090
Fair Value Measurements on Recurring Basis | Money Market Funds
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Cash equivalents	26,719	37,878
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	26,719	37,878
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	163,819	180,049
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	163,819	180,049
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	103,699	111,832
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	103,699	111,832
Fair Value Measurements on Recurring Basis | Commercial Paper
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Short-term investments	63,003	52,941
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	63,003	52,941
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		9,956
Short-term investments	30,784	16,043
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]
Cash equivalents		9,956
Short-term investments	30,784	16,043
Fair Value Measurements on Recurring Basis | Non U S Government And Supranational Debt Securities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Short-term investments	17,536	25,318
Fair Value Measurements on Recurring Basis | Non U S Government And Supranational Debt Securities | Level 2
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Short-term investments	$ 17,536	$ 25,318

Balance Sheet Detail - Summary

Balance Sheet Detail - Summary of Property and Equipment (Detail) - USD ($) $ in Thousands	Mar. 31, 2023	Dec. 31, 2022
Property Plant And Equipment [Line Items]
Property and equipment, gross	$ 4,179	$ 4,143
Less: accumulated depreciation	(1,809)	(1,603)
Property and equipment, net	2,370	2,540
Laboratory and Computer Equipment
Property Plant And Equipment [Line Items]
Property and equipment, gross	1,568	1,568
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	$ 1,068	$ 1,032

Balance Sheet Detail - Summar_2

Balance Sheet Detail - Summary of Current Accrued Expenses (Detail) - USD ($) $ in Thousands	Mar. 31, 2023	Dec. 31, 2022
Accrued Liabilities, Current [Abstract]
Accounts payable	$ 3,291	$ 1,533
Accrued clinical trial research and development expenses	1,576	2,440
Accrued other research and development expenses	5,084	5,030
Accrued compensation and benefits	5,073	10,300
Other accrued expenses	1,877	2,436
Total accounts payable and accrued expenses	$ 16,901	$ 21,739

Leases - Additional Information

Leases - Additional Information (Detail) - USD ($)	1 Months Ended		3 Months Ended
	May 31, 2020	Mar. 31, 2020	Mar. 31, 2023	Mar. 31, 2022	Dec. 31, 2022	May 31, 2022
Lessee Lease Description [Line Items]
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 July 2024 and November 2025.
Lease option to extend, description			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
Weighted-average discount rate			5.50%		5.50%
Weighted-average remaining lease term			2 years 1 month 6 days		2 years 3 months 18 days
Total cash paid for amounts included in the measurement of lease liabilities			$ 600,000	$ 600,000
ROU assets obtained in exchange for operating lease liabilities			0	0
ASC 842
Lessee Lease Description [Line Items]
Total operating lease rent expense			500,000	$ 500,000
San Diego Corporate Headquarters Lease
Lessee Lease Description [Line Items]
Operating lease, existence of option to extend		true
Lease agreement additional extended lease term	5 years
Tenant improvement allowance	$ 1,000,000
San Diego Lease for Lab and Office Space
Lessee Lease Description [Line Items]
Tenant improvement allowance						$ 100,000
Office Lease in Boston | Letter of Credit
Lessee Lease Description [Line Items]
Letter of Credit			$ 200,000
Boston Lease
Lessee Lease Description [Line Items]
Operating lease, existence of option to extend	true
Lease agreement additional extended lease term		5 years

Leases - Schedule of Maturities

Leases - Schedule of Maturities of Lease Liabilities (Detail) $ in Thousands	Mar. 31, 2023 USD ($)
Leases [Abstract]
2023 (remaining)	$ 1,789
2024	1,863
2025	929
Total lease payments	4,581
Less: imputed interest	(241)
Total operating lease liabilities	$ 4,340

Share-Based Compensation - Summ

Share-Based Compensation - Summary of Share-based Compensation Expense (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Share-based compensation expense	$ 6,838	$ 6,650
Research and development
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Share-based compensation expense	3,073	2,456
General and administrative
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Share-based compensation expense	$ 3,765	$ 4,194

Share-Based Compensation - Addi

Share-Based Compensation - Additional Information (Detail) $ in Millions	3 Months Ended
	Mar. 31, 2023 USD ($)
Employee Stock Option
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Unrecognized estimated stock option compensation expenses	$ 49.6
Weighted average service period	2 years 9 months 18 days
Restricted Stock Units
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Unrecognized estimated restricted stock units compensation expenses	$ 14.3
Weighted average service period	2 years 9 months 18 days