Kura Oncology (KURA) 10-Q 4 May 22 2022 Q1 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	3 Months Ended
	Mar. 31, 2022	Apr. 29, 2022
Cover [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Mar. 31, 2022
Document Fiscal Year Focus	2022
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		66,636,105
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, 2022	Dec. 31, 2021
Current assets:
Cash and cash equivalents	$ 33,832	$ 90,672
Short-term investments	446,243	427,288
Prepaid expenses and other current assets	6,959	4,329
Total current assets	487,034	522,289
Property and equipment, net	2,567	2,673
Restricted cash	210	210
Operating lease right-of-use assets	5,149	5,573
Other long-term assets	3,625	3,306
Total assets	498,585	534,051
Current liabilities:
Accounts payable	1,337	3,236
Accrued expenses	14,112	16,956
Current operating lease liabilities	2,276	2,263
Total current liabilities	17,725	22,455
Long-term operating lease liabilities	4,114	4,612
Other long-term liabilities	496	375
Total liabilities	22,335	27,442
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; 66,636 and 66,572 shares issued and outstanding as of March 31, 2022 and December 31, 2021, respectively	7	7
Additional paid-in capital	948,312	941,359
Accumulated other comprehensive income (loss)	(6,648)	(1,789)
Accumulated deficit	(465,421)	(432,968)
Total stockholders' equity	476,250	506,609
Total liabilities and stockholders' equity	$ 498,585	$ 534,051

Condensed Balance Sheets (Una_2

Condensed Balance Sheets (Unaudited) (Parenthetical) - $ / shares	Mar. 31, 2022	Dec. 31, 2021
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	66,636,000	66,572,000
Common stock, shares outstanding	66,636,000	66,572,000

Condensed Statements of Operati

Condensed Statements of Operations and Comprehensive Loss (Unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Operating Expenses:
Research and development	$ 20,913	$ 20,324
General and administrative	11,869	10,572
Total operating expenses	32,782	30,896
Other Income (Expense):
Interest and other income, net	329	310
Interest expense		(108)
Total other income, net	329	202
Net Loss	$ (32,453)	$ (30,694)
Net loss per share, basic and diluted	$ (0.49)	$ (0.46)
Weighted average number of shares used in computing net loss per share, basic and diluted	66,607	66,218
Comprehensive Loss:
Net loss	$ (32,453)	$ (30,694)
Other comprehensive loss:
Unrealized loss on marketable securities and foreign currency	(4,859)	(128)
Comprehensive Loss	$ (37,312)	$ (30,822)

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, 2020	$ 610,905	$ 7	$ 913,354	$ 46	$ (302,502)
Beginning balance (in shares) at Dec. 31, 2020		66,194
Share-based compensation expense	5,075		5,075
Issuance of common stock under equity incentive plan	829		829
Issuance of common stock under equity incentive plan (in shares)		69
Other comprehensive income (loss)	(128)			(128)
Net loss	(30,694)				(30,694)
Ending balance at Mar. 31, 2021	585,987	$ 7	919,258	(82)	(333,196)
Ending balance (in shares) at Mar. 31, 2021		66,263
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 incentive plan	303		303
Issuance of common stock under equity incentive plan (in 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

Condensed Statements of Cash Fl

Condensed Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Operating Activities
Net loss	$ (32,453)	$ (30,694)
Adjustments to reconcile net loss to net cash used in operating activities:
Share-based compensation expense	6,650	5,075
Depreciation expense	177	108
Amortization of premium and accretion of discounts on marketable securities, net	1,100	850
Changes in operating assets and liabilities:
Prepaid expenses and other current assets	(2,630)	(2,860)
Other long-term assets	105	410
Accounts payable and accrued expenses	(5,251)	(1,452)
Other long-term liabilities	121	46
Net cash used in operating activities	(32,181)	(28,517)
Investing Activities
Purchases of marketable securities	(51,400)	(223,158)
Maturities of marketable securities	26,487	36,969
Purchases of property and equipment	(49)	(31)
Net cash used in investing activities	(24,962)	(186,220)
Financing Activities
Proceeds from issuance of stock under equity incentive plan	303	829
Repayment of long-term debt		(750)
Net cash (used in) provided by financing activities	303	79
Net decrease in cash, cash equivalents and restricted cash	(56,840)	(214,658)
Cash, cash equivalents and restricted cash at beginning of period	90,882	325,703
Cash, cash equivalents and restricted cash at end of period	$ 34,042	$ 111,045

Organization and Basis of Prese

Organization and Basis of Presentation	3 Months Ended
	Mar. 31, 2022
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, 2021, as filed with the Securities and Exchange Commission on February 24, 2022, from which we derived our balance sheet as of December 31, 2021. 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. Though the impact of the COVID-19 pandemic to our business and operating results presents additional uncertainty, we continue to use the best information available to inform our critical accounting estimates. By their nature, estimates are subject to an inherent degree of uncertainty and, as such, actual results may differ from management’s estimates. The extent to which the COVID-19 pandemic has impacted and may continue to impact our business will depend on future developments, which are highly uncertain and cannot be predicted with any confidence, such as the duration and severity of the COVID-19 pandemic, steps required or mandated by governments to mitigate the impact of COVID-19 or the effectiveness of actions to prevent, contain and treat COVID-19, particularly in the geographies where we, our third-party manufacturers, contract research organizations or current and planned clinical trial sites operate. We cannot presently predict the scope and severity of any potential business disruptions, interruptions or shutdowns. If we or any of the third parties with whom we engage, however, were to experience shutdowns or other business disruptions, our ability to conduct our business in the manner and on the timelines presently planned could be materially and negatively affected, which could have a material adverse impact on our business and our results of operations and financial condition.

Summary of Significant Accounti

Summary of Significant Accounting Policies	3 Months Ended
	Mar. 31, 2022
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	2. Summary of Significant Accounting Policies Reclassifications Certain prior period balances have been reclassified to conform to the current period presentation. 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, 2022 , 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, 2022 December 31, 2021 March 31, 2021 December 31, 2020 Cash and cash equivalents $ 33,832 $ 90,672 $ 110,835 $ 325,493 Restricted cash 210 210 210 210 Total $ 34,042 $ 90,882 $ 111,045 $ 325,703 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. 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, 2022 and 2021, 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, a warrant 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, 2022 and 2021 totaling approximately 9,501,000 and 6,834,000 , 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, 2022
Investments All Other Investments [Abstract]
Investments	3. Investments We invest in available-for-sale securities consisting of money market funds, corporate debt securities, U.S. Treasury securities, commercial paper, non-U.S. government debt securities, supranational 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: March 31, 2022 Maturities Amortized Unrealized Unrealized Fair Value Cash equivalents: Money market funds 1 or less $ 29,245 $ — $ — $ 29,245 Short-term investments: Corporate debt securities 3 or less 192,065 — ( 3,366 ) 188,699 U.S. Treasury securities 3 or less 170,309 2 ( 2,372 ) 167,939 Commercial paper 1 or less 58,427 — — 58,427 Non-U.S. government and supranational debt securities 3 or less 23,094 — ( 719 ) 22,375 U.S. Agency bonds 2 or less 8,995 — ( 192 ) 8,803 Total short-term investments 452,890 2 ( 6,649 ) 446,243 Total $ 482,135 $ 2 $ ( 6,649 ) $ 475,488 December 31, 2021 Maturities Amortized Unrealized Unrealized Fair Value Cash equivalents: Money market funds 1 or less $ 79,895 $ — $ — $ 79,895 Short-term investments: Corporate debt securities 3 or less 208,064 — ( 892 ) 207,172 U.S. Treasury securities 3 or less 135,452 — ( 619 ) 134,833 Commercial paper 1 or less 53,439 — — 53,439 Non-U.S. government and supranational debt securities 3 or less 23,122 — ( 214 ) 22,908 U.S. Agency bonds 2 or less 8,994 — ( 58 ) 8,936 Total short-term investments 429,071 — ( 1,783 ) 427,288 Total $ 508,966 $ — $ ( 1,783 ) $ 507,183 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, 2022 and December 31, 2021 , short-term investments of $ 292.0 million and $ 246.9 million, respectively, had maturities less than one year, and short-term investments of $ 154.2 million and $ 180.4 million, respectively, had maturities between one to three years. We had no realized gains or losses for the three months ended March 31, 2022 and 2021. As of March 31, 2022 , 36 available-for-sale securities with a fair market value of $ 366.8 million were in gross unrealized loss positions, none of which 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, 2022 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, 2022 and December 31, 2021. 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 were $ 1.6 million and $ 1.4 million at March 31, 2022 and December 31, 2021, respectively. We have not written off any accrued interest receivables for the three months ended March 31, 2022 and 2021.

Fair Value Measurements

Fair Value Measurements	3 Months Ended
	Mar. 31, 2022
Fair Value Disclosures [Abstract]
Fair Value Measurements	4. Fair Value Measurements As of March 31, 2022 and December 31, 2021, 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, non-U.S. government debt securities, supranational 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: March 31, 2022 Total Level 1 Level 2 Cash equivalents: Money market funds $ 29,245 $ 29,245 $ — Short-term investments: Corporate debt securities 188,699 — 188,699 U.S. Treasury securities 167,939 167,939 — Commercial paper 58,427 — 58,427 Non-U.S. government and supranational debt securities 22,375 — 22,375 U.S. Agency bonds 8,803 — 8,803 Total short-term investments 446,243 167,939 278,304 Total $ 475,488 $ 197,184 $ 278,304 December 31, 2021 Total Level 1 Level 2 Cash equivalents: Money market funds $ 79,895 $ 79,895 $ — Short-term investments: Corporate debt securities 207,172 — 207,172 U.S. Treasury securities 134,833 134,833 — Commercial paper 53,439 — 53,439 Non-U.S. government and supranational debt securities 22,908 — 22,908 U.S. Agency bonds 8,936 — 8,936 Total short-term investments 427,288 134,833 292,455 Total $ 507,183 $ 214,728 $ 292,455

Balance Sheet Detail

Balance Sheet Detail	3 Months Ended
	Mar. 31, 2022
Balance Sheet Related Disclosures [Abstract]
Balance Sheet Detail	5. Balance Sheet Detail Property and equipment consisted of the following, in thousands: March 31, 2022 December 31, 2021 Leasehold improvements $ 1,543 $ 1,532 Furniture and fixtures 1,032 1,032 Laboratory and computer equipment 1,013 953 Property and equipment, gross 3,588 3,517 Less: accumulated depreciation ( 1,021 ) ( 844 ) Property and equipment, net $ 2,567 $ 2,673 Current accrued expenses consisted of the following, in thousands: March 31, 2022 December 31, 2021 Accrued clinical trial research and development expenses $ 3,475 $ 2,619 Accrued other research and development expenses 4,436 5,341 Accrued compensation and benefits 4,494 7,923 Other accrued expenses 1,707 1,073 Total current accrued expenses $ 14,112 $ 16,956

Leases

Leases	3 Months Ended
	Mar. 31, 2022
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, 2022 are as follows, in thousands: Year Ending December 31, 2022 (remaining) $ 1,747 2023 2,375 2024 1,863 2025 929 Total lease payments 6,914 Less: imputed interest ( 524 ) Total operating lease liabilities $ 6,390 As of March 31, 2022 and December 31, 2021 , the weighted-average discount rate was 5.5 % for both periods, and the weighted-average remaining lease term was 3.0 years and 3.3 years, respectively. Total cash paid for amounts included in the measurement of operating lease liabilities was $ 0.6 million and $ 0.5 million for the three months ended March 31, 2022 and 2021 , respectively. There were no operating lease ROU assets obtained in exchange for operating lease liabilities for the three months ended March 31, 2022 and 2021, respectively. Total operating lease expense for the three months ended March 31, 2022 and 2021 was approximately $ 0.5 million in both periods.

Stockholders' Equity

Stockholders' Equity	3 Months Ended
	Mar. 31, 2022
Equity [Abstract]
Stockholders' Equity	7. Stockholders’ Equity In March 2019, we entered into a Common Stock Sales Agreement with SVB Leerink LLC and Stifel, Nicolaus & Company, Incorporated, under which we could offer and sell, from time to time, at our sole discretion, shares of our common stock having an aggregate offering price of up to $ 75.0 million. We did no t sell any shares of our common stock under the agreement. In February 2022, we terminated the agreement with SVB Leerink LLC and Stifel, Nicolaus & Company, Incorporated. In February 2022, we entered into a new Common Stock Sales Agreement with SVB Securities LLC, Credit Suisse Securities (USA) 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 no t yet sold any shares of our common stock under the ATM Facility.

Share-Based Compensation

Share-Based Compensation	3 Months Ended
	Mar. 31, 2022
Disclosure Of Compensation Related Costs Sharebased Payments [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 March 31, 2022 2021 Research and development $ 2,456 $ 1,371 General and administrative 4,194 3,704 Total share-based compensation expense $ 6,650 $ 5,075 As of March 31, 2022 , unrecognized estimated compensation expense related to stock options and restricted stock units was approximately $ 57.5 million and $ 9.1 million, respectively, which is expected to be recognized over a weighted average period of approximately 2.8 years and 3.6 years, respectively.

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	3 Months Ended
	Mar. 31, 2022
Accounting Policies [Abstract]
Reclassifications	Reclassifications Certain prior period balances have been reclassified to conform to the current period presentation.
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, 2022 , 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, 2022 December 31, 2021 March 31, 2021 December 31, 2020 Cash and cash equivalents $ 33,832 $ 90,672 $ 110,835 $ 325,493 Restricted cash 210 210 210 210 Total $ 34,042 $ 90,882 $ 111,045 $ 325,703
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.
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, 2022 and 2021, 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, a warrant 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, 2022 and 2021 totaling approximately 9,501,000 and 6,834,000 , 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, 2022
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, 2022 December 31, 2021 March 31, 2021 December 31, 2020 Cash and cash equivalents $ 33,832 $ 90,672 $ 110,835 $ 325,493 Restricted cash 210 210 210 210 Total $ 34,042 $ 90,882 $ 111,045 $ 325,703

Investments (Tables)

Investments (Tables)	3 Months Ended
	Mar. 31, 2022
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, 2022 Maturities Amortized Unrealized Unrealized Fair Value Cash equivalents: Money market funds 1 or less $ 29,245 $ — $ — $ 29,245 Short-term investments: Corporate debt securities 3 or less 192,065 — ( 3,366 ) 188,699 U.S. Treasury securities 3 or less 170,309 2 ( 2,372 ) 167,939 Commercial paper 1 or less 58,427 — — 58,427 Non-U.S. government and supranational debt securities 3 or less 23,094 — ( 719 ) 22,375 U.S. Agency bonds 2 or less 8,995 — ( 192 ) 8,803 Total short-term investments 452,890 2 ( 6,649 ) 446,243 Total $ 482,135 $ 2 $ ( 6,649 ) $ 475,488 December 31, 2021 Maturities Amortized Unrealized Unrealized Fair Value Cash equivalents: Money market funds 1 or less $ 79,895 $ — $ — $ 79,895 Short-term investments: Corporate debt securities 3 or less 208,064 — ( 892 ) 207,172 U.S. Treasury securities 3 or less 135,452 — ( 619 ) 134,833 Commercial paper 1 or less 53,439 — — 53,439 Non-U.S. government and supranational debt securities 3 or less 23,122 — ( 214 ) 22,908 U.S. Agency bonds 2 or less 8,994 — ( 58 ) 8,936 Total short-term investments 429,071 — ( 1,783 ) 427,288 Total $ 508,966 $ — $ ( 1,783 ) $ 507,183

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	3 Months Ended
	Mar. 31, 2022
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, 2022 Total Level 1 Level 2 Cash equivalents: Money market funds $ 29,245 $ 29,245 $ — Short-term investments: Corporate debt securities 188,699 — 188,699 U.S. Treasury securities 167,939 167,939 — Commercial paper 58,427 — 58,427 Non-U.S. government and supranational debt securities 22,375 — 22,375 U.S. Agency bonds 8,803 — 8,803 Total short-term investments 446,243 167,939 278,304 Total $ 475,488 $ 197,184 $ 278,304 December 31, 2021 Total Level 1 Level 2 Cash equivalents: Money market funds $ 79,895 $ 79,895 $ — Short-term investments: Corporate debt securities 207,172 — 207,172 U.S. Treasury securities 134,833 134,833 — Commercial paper 53,439 — 53,439 Non-U.S. government and supranational debt securities 22,908 — 22,908 U.S. Agency bonds 8,936 — 8,936 Total short-term investments 427,288 134,833 292,455 Total $ 507,183 $ 214,728 $ 292,455

Balance Sheet Detail (Tables)

Balance Sheet Detail (Tables)	3 Months Ended
	Mar. 31, 2022
Balance Sheet Related Disclosures [Abstract]
Summary of Property and Equipment	Property and equipment consisted of the following, in thousands: March 31, 2022 December 31, 2021 Leasehold improvements $ 1,543 $ 1,532 Furniture and fixtures 1,032 1,032 Laboratory and computer equipment 1,013 953 Property and equipment, gross 3,588 3,517 Less: accumulated depreciation ( 1,021 ) ( 844 ) Property and equipment, net $ 2,567 $ 2,673
Summary of Current Accrued Expenses	Current accrued expenses consisted of the following, in thousands: March 31, 2022 December 31, 2021 Accrued clinical trial research and development expenses $ 3,475 $ 2,619 Accrued other research and development expenses 4,436 5,341 Accrued compensation and benefits 4,494 7,923 Other accrued expenses 1,707 1,073 Total current accrued expenses $ 14,112 $ 16,956

Leases (Tables)

Leases (Tables)	3 Months Ended
	Mar. 31, 2022
Leases [Abstract]
Schedule of Maturities of Lease Liabilities	Maturities of lease liabilities as of March 31, 2022 are as follows, in thousands: Year Ending December 31, 2022 (remaining) $ 1,747 2023 2,375 2024 1,863 2025 929 Total lease payments 6,914 Less: imputed interest ( 524 ) Total operating lease liabilities $ 6,390

Share-Based Compensation (Table

Share-Based Compensation (Tables)	3 Months Ended
	Mar. 31, 2022
Disclosure Of Compensation Related Costs Sharebased Payments [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, 2022 2021 Research and development $ 2,456 $ 1,371 General and administrative 4,194 3,704 Total share-based compensation expense $ 6,650 $ 5,075

Summary of Significant Accoun_4

Summary of Significant Accounting Policies - Additional Information (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021	Dec. 31, 2021	Dec. 31, 2020
Summary Of Significant Accounting Policies [Line Items]
Restricted cash pledged as collateral	$ 210	$ 210	$ 210	$ 210
Total potentially dilutive securities	9,501,000	6,834,000
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, 2022	Dec. 31, 2021	Mar. 31, 2021	Dec. 31, 2020
Accounting Policies [Abstract]
Cash and cash equivalents	$ 33,832	$ 90,672	$ 110,835	$ 325,493
Restricted cash	210	210	210	210
Total	$ 34,042	$ 90,882	$ 111,045	$ 325,703

Investments - Investments Measu

Investments - Investments Measured at Fair Value on Recurring Basis (Detail) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2022	Dec. 31, 2021
Schedule Of Available For Sale Securities [Line Items]
Short-term investments, Fair Value	$ 446,243	$ 427,288
Fair Value Measurements on Recurring Basis
Schedule Of Available For Sale Securities [Line Items]
Short-term investments, Amortized Cost	452,890	429,071
Short-term investments, Unrealized Gains	2
Short-term investments, Unrealized Losses	(6,649)	(1,783)
Short-term investments, Fair Value	446,243	427,288
Cash equivalents and Short-term investments, Amortized Cost	482,135	508,966
Cash equivalents and Short-term investments, Unrealized Gains	2
Cash equivalents and Short-term investments, Unrealized Losses	(6,649)	(1,783)
Cash equivalents and Short-term investments, Estimated Fair Value	$ 475,488	$ 507,183
Fair Value Measurements on Recurring Basis | Money Market Funds
Schedule Of Available For Sale Securities [Line Items]
Maturities (years)	1 or less	1 or less
Cash equivalents, Amortized Cost	$ 29,245	$ 79,895
Cash equivalents, Fair Value	29,245	79,895
Fair Value Measurements on Recurring Basis | Corporate Debt Securities
Schedule Of Available For Sale Securities [Line Items]
Short-term investments, Amortized Cost	192,065	208,064
Short-term investments, Unrealized Losses	(3,366)	(892)
Short-term investments, Fair Value	$ 188,699	$ 207,172
Fair Value Measurements on Recurring Basis | Corporate Debt Securities | Maximum
Schedule Of Available For Sale Securities [Line Items]
Maturities (years)	3 years	3 years
Fair Value Measurements on Recurring Basis | U.S. Treasury Securities
Schedule Of Available For Sale Securities [Line Items]
Short-term investments, Amortized Cost	$ 170,309	$ 135,452
Short-term investments, Unrealized Gains	2
Short-term investments, Unrealized Losses	(2,372)	(619)
Short-term investments, Fair Value	$ 167,939	$ 134,833
Fair Value Measurements on Recurring Basis | U.S. Treasury Securities | Maximum
Schedule Of Available For Sale Securities [Line Items]
Maturities (years)	3 years	3 years
Fair Value Measurements on Recurring Basis | Commercial Paper
Schedule Of Available For Sale Securities [Line Items]
Short-term investments, Amortized Cost	$ 58,427	$ 53,439
Short-term investments, Fair Value	$ 58,427	$ 53,439
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 | Non U S Government And Supranational Debt Securities
Schedule Of Available For Sale Securities [Line Items]
Short-term investments, Amortized Cost	$ 23,094	$ 23,122
Short-term investments, Unrealized Losses	(719)	(214)
Short-term investments, Fair Value	$ 22,375	$ 22,908
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)	3 years	3 years
Fair Value Measurements on Recurring Basis | U.S. Agency Bonds
Schedule Of Available For Sale Securities [Line Items]
Short-term investments, Amortized Cost	$ 8,995	$ 8,994
Short-term investments, Unrealized Losses	(192)	(58)
Short-term investments, Fair Value	$ 8,803	$ 8,936
Fair Value Measurements on Recurring Basis | U.S. Agency Bonds | 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, 2022USD ($)Security	Dec. 31, 2021USD ($)
Investments All Other Investments [Abstract]
Short-term investments with maturities less than one year	$ 292,000	$ 246,900
Short-term investments with maturities between one to three years	$ 154,200	180,400
Short-term investments maturities, description	As of March 31, 2022 and December 31, 2021, short-term investments of $292.0 million and $246.9 million, respectively, had maturities less than one year, and short-term investments of $154.2 million and $180.4 million, respectively, had maturities between one to three years.
Allowance for credit losses	$ 0	0
Available for sale securities gross unrealized loss positions for less than twelve months	$ 366,800
Number of available-for-sale securities | Security	36
Accrued interest receivable on available-for-sale securities	$ 1,600	$ 1,400

Fair Value Measurements - Sched

Fair Value Measurements - Schedule Of Fair Value Measurements, By Major Security Type (Detail) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Short-term investments	$ 446,243	$ 427,288
Fair Value Measurements on Recurring Basis
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Short-term investments	446,243	427,288
Cash equivalents and short-term investments	475,488	507,183
Fair Value Measurements on Recurring Basis | Level 1
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Short-term investments	167,939	134,833
Cash equivalents and short-term investments	197,184	214,728
Fair Value Measurements on Recurring Basis | Level 2
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Short-term investments	278,304	292,455
Cash equivalents and short-term investments	278,304	292,455
Fair Value Measurements on Recurring Basis | Money Market Funds
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Cash equivalents	29,245	79,895
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	29,245	79,895
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	188,699	207,172
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	188,699	207,172
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	167,939	134,833
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	167,939	134,833
Fair Value Measurements on Recurring Basis | Commercial Paper
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Short-term investments	58,427	53,439
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	58,427	53,439
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	22,375	22,908
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	22,375	22,908
Fair Value Measurements on Recurring Basis | U S Agency Bonds
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Short-term investments	8,803	8,936
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	$ 8,803	$ 8,936

Balance Sheet Detail - Summary

Balance Sheet Detail - Summary of Property and Equipment (Detail) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Property Plant And Equipment [Line Items]
Property and equipment, gross	$ 3,588	$ 3,517
Less: accumulated depreciation	(1,021)	(844)
Property and equipment, net	2,567	2,673
Leasehold Improvements
Property Plant And Equipment [Line Items]
Property and equipment, gross	1,543	1,532
Furniture and Fixtures
Property Plant And Equipment [Line Items]
Property and equipment, gross	1,032	1,032
Laboratory and Computer Equipment
Property Plant And Equipment [Line Items]
Property and equipment, gross	$ 1,013	$ 953

Balance Sheet Detail - Summar_2

Balance Sheet Detail - Summary of Current Accrued Expenses (Detail) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Accrued Liabilities, Current [Abstract]
Accrued clinical trial research and development expenses	$ 3,475	$ 2,619
Accrued other research and development expenses	4,436	5,341
Accrued compensation and benefits	4,494	7,923
Other accrued expenses	1,707	1,073
Total current accrued expenses	$ 14,112	$ 16,956

Leases - Additional Information

Leases - Additional Information (Detail) - USD ($)	1 Months Ended		3 Months Ended
	May 31, 2020	Mar. 31, 2020	Mar. 31, 2022	Mar. 31, 2021	Dec. 31, 2021
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			3 years		3 years 3 months 18 days
Total cash paid for amounts included in the measurement of lease liabilities			$ 600,000	$ 500,000
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, 2022USD ($)
Leases [Abstract]
2022 (remaining)	$ 1,747
2023	2,375
2024	1,863
2025	929
Total lease payments	6,914
Less: imputed interest	(524)
Operating Lease Liability	$ 6,390

Stockholder's Equity - Addition

Stockholder's Equity - Additional Information (Detail) - ATM Facility - USD ($) $ in Millions	1 Months Ended		3 Months Ended
	Feb. 28, 2022	Mar. 31, 2019	Mar. 31, 2022
SVB Leerink LLC and Stifel, Nicolaus & Company, Incorporated
Class of Stock [Line Items]
Common stock, shares issued			0
SVB Leerink LLC and Stifel, Nicolaus & Company, Incorporated | Maximum
Class of Stock [Line Items]
Aggregate offering price		$ 75
SVB Securities LLC, Credit Suisse Securities (USA) LLC and Cantor Fitzgerald & Co.
Class of Stock [Line Items]
Common stock, shares issued			0
SVB Securities LLC, Credit Suisse Securities (USA) LLC and Cantor Fitzgerald & Co. | Maximum
Class of Stock [Line Items]
Aggregate offering price	$ 150

Share-Based Compensation - Summ

Share-Based Compensation - Summary of Share-based Compensation Expense (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Share-based compensation expense	$ 6,650	$ 5,075
Research and development
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Share-based compensation expense	2,456	1,371
General and administrative
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Share-based compensation expense	$ 4,194	$ 3,704

Share-Based Compensation - Addi

Share-Based Compensation - Additional Information (Detail) $ in Millions	3 Months Ended
	Mar. 31, 2022USD ($)
Employee Stock Option
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Unrecognized estimated stock option compensation expenses	$ 57.5
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	$ 9.1
Weighted average service period	3 years 7 months 6 days