Krystal Biotech (KRYS) 10-Q 9 May 22 2022 Q1 Quarterly report Financial data

Cover

Cover - shares	3 Months Ended
	Mar. 31, 2022	Apr. 29, 2022
Cover [Abstract]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Mar. 31, 2022
Document Transition Report	false
Entity File Number	001-38210
Entity Registrant Name	Krystal Biotech, Inc.
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	82-1080209
Entity Address, Address Line One	2100 Wharton Street
Entity Address, Address Line Two	Suite 701
Entity Address, City or Town	Pittsburgh
Entity Address, State or Province	PA
Entity Address, Postal Zip Code	15203
City Area Code	412
Local Phone Number	586-5830
Title of 12(b) Security	Common Stock
Trading Symbol	KRYS
Security Exchange Name	NASDAQ
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		25,635,138
Amendment Flag	false
Document Fiscal Year Focus	2022
Document Fiscal Period Focus	Q1
Entity Central Index Key	0001711279
Current Fiscal Year End Date	--12-31

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Current assets
Cash and cash equivalents	$ 269,303	$ 341,246
Short-term investments	165,329	96,850
Prepaid expenses and other current assets	3,366	4,171
Total current assets	437,998	442,267
Property and equipment, net	136,927	112,355
Long-term investments	33,339	64,371
Right-of-use assets	8,453	7,228
Other non-current assets	157	74
Total assets	616,874	626,295
Current liabilities
Accounts payable	8,209	8,398
Current portion of lease liability	1,411	1,041
Accrued expenses and other current liabilities	50,817	16,297
Total current liabilities	60,437	25,736
Lease liability	7,883	6,983
Total liabilities	68,320	32,719
Commitments and contingencies (Note 6)
Stockholders' equity
Preferred stock; $0.00001 par value; 20,000,000 shares authorized at    March 31, 2022 (unaudited) and December 31, 2021; 2,061,773    shares issued, and no shares outstanding at March 31, 2022    (unaudited) and December 31, 2021	0	0
Common stock; $0.00001 par value; 80,000,000 shares authorized at    March 31, 2022 (unaudited) and December 31, 2021; 25,199,081    shares issued and outstanding at March 31, 2022    (unaudited); and 25,207,985 shares issued and outstanding at December 31, 2021	0	0
Additional paid-in capital	740,500	734,523
Accumulated other comprehensive expense	(1,197)	(163)
Accumulated deficit	(190,749)	(140,784)
Total stockholders' equity	548,554	593,576
Total liabilities and stockholders' equity	$ 616,874	$ 626,295

Condensed Consolidated Balanc_2

Condensed Consolidated Balance Sheets (Parenthetical) - $ / shares	Mar. 31, 2022	Dec. 31, 2021
Statement of Financial Position [Abstract]
Preferred stock, par value (in dollars per share)	$ 0.00001	$ 0.00001
Preferred stock, shares authorized	20,000,000	20,000,000
Preferred stock, shares issued	2,061,773	2,061,773
Preferred stock, shares outstanding	0	0
Common stock, par value (in dollars per share)	$ 0.00001	$ 0.00001
Common stock, shares authorized	80,000,000	80,000,000
Common stock, shares issued	25,199,081	25,207,985
Common stock, shares outstanding		25,207,985

Condensed Consolidated Statemen

Condensed Consolidated Statements of Operations and Comprehensive Loss - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Expenses
Research and development	$ 9,314	$ 6,201
General and administrative	15,908	8,152
Litigation settlement	25,000	0
Total operating expenses	50,222	14,353
Loss from operations	(50,222)	(14,353)
Other Income (Expense)
Interest and other income, net	257	33
Interest expense	0	(1,492)
Net loss	(49,965)	(15,812)
Unrealized loss on available-for-sale securities and other	(1,034)	(3)
Comprehensive loss	$ (50,999)	$ (15,815)
Net loss per common share: basic (in dollars per share)	$ (1.99)	$ (0.74)
Net loss per common share: diluted (in dollars per share)	$ (1.99)	$ (0.74)
Weighted-average common shares outstanding: basic	25,114,453	21,253,508
Weighted-average common shares outstanding: diluted	25,114,453	21,253,508

Condensed Consolidated Statem_2

Condensed Consolidated Statements of Stockholders' Equity - USD ($) $ in Thousands	Total	Common Stock	Additional Paid-in Capital	Accumulated Other Comprehensive Expense	Accumulated Deficit
Beginning balance (in shares) at Dec. 31, 2020		19,714,220
Beginning balance at Dec. 31, 2020	$ 292,084	$ 0	$ 363,292	$ 6	$ (71,214)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock, net, (in shares)		2,489,837
Issuance of common stock, net	152,033		152,033
Stock-based compensation expense	2,350		2,350
Unrealized loss on investments and other	(3)			(3)
Net loss	(15,812)				(15,812)
Ending balance (in shares) at Mar. 31, 2021		22,204,057
Ending balance at Mar. 31, 2021	430,652	$ 0	517,675	3	(87,026)
Beginning balance (in shares) at Dec. 31, 2021		25,207,985
Beginning balance at Dec. 31, 2021	593,576	$ 0	734,523	(163)	(140,784)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock, net, (in shares)		1,475
Issuance of common stock, net	55		55
Restricted stock surrendered for taxes (in shares)		(10,379)
Restricted stock surrendered for taxes	(649)		(649)
Stock-based compensation expense	6,571		6,571
Unrealized loss on investments and other	(1,034)			(1,034)
Net loss	(49,965)				(49,965)
Ending balance (in shares) at Mar. 31, 2022		25,199,081
Ending balance at Mar. 31, 2022	$ 548,554	$ 0	$ 740,500	$ (1,197)	$ (190,749)

Condensed Consolidated Statem_3

Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Operating Activities
Net loss	$ (49,965)	$ (15,812)
Adjustments to reconcile net loss to net cash used in operating activities
Depreciation and amortization	1,015	536
Stock-based compensation expense	6,430	2,313
Non-cash interest expense	0	1,492
Other, net	(135)	12
Changes in operating assets and liabilities
Prepaid expenses and other current assets	820	1,312
Other non-current assets	9	0
Lease liability	(126)	(77)
Accounts payable	(554)	294
Accrued expenses and other current liabilities	2,013	276
Accrued legal settlement	25,000	0
Net cash used in operating activities	(15,493)	(9,654)
Investing Activities
Purchases of property and equipment	(17,191)	(2,473)
Purchases of investments	(62,754)	0
Proceeds from maturities of investments	24,037	1,726
Net cash used in investing activities	(55,908)	(747)
Financing Activities
Issuance of common stock, net	107	152,264
Taxes paid related to settlement of restricted stock awards	(649)	0
Repayment of ASTRA build to suit liability	0	(7,960)
Net cash provided by (used in) financing activities	(542)	144,304
Net increase (decrease) in cash and cash equivalents	(71,943)	133,903
Cash and cash equivalents at beginning of period	341,246	268,269
Cash and cash equivalents at end of period	269,303	402,172
Supplemental Disclosures of Non-Cash Investing and Financing Activities
Unpaid purchases of property and equipment	14,507	2,615
Initial recognition of right-of-use assets	1,394	0
Unpaid offering costs	$ 24	$ 214

Organization

Organization	3 Months Ended
	Mar. 31, 2022
Accounting Policies [Abstract]
Organization	Organization Krystal Biotech, Inc. (the “Company,” or “we” or other similar pronouns) commenced operations on April 15, 2016. On March 31, 2017, the Company converted from a California limited liability company to a Delaware C-corporation, and changed its name from Krystal Biotech LLC to Krystal Biotech, Inc. On June 19, 2018, the Company incorporated Krystal Australia Pty Ltd., an Australian proprietary limited company, a wholly-owned subsidiary, for the purpose of undertaking preclinical and clinical studies in Australia. On April 24, 2019, the Company incorporated Jeune Aesthetics, Inc., formerly known as Jeune, Inc. ("Jeune"), in Delaware, a wholly-owned subsidiary, for the purpose of undertaking preclinical and clinical studies for aesthetic skin conditions. On January 7, 2022, the Company incorporated Krystal Biotech Switzerland GmbH, for the purpose of establishing initial operations in Europe for the development and commercialization of Krystal's pipeline. We are a clinical stage biotechnology company leading the field of redosable gene delivery. Using our patented platform that is based on engineered herpes simplex virus type 1 ("HSV-1"), we create vectors that efficiently deliver therapeutic transgenes to cells of interest in multiple organ systems. The cell’s own machinery then transcribes and translates the encoded effector to treat or prevent disease. We formulate our vectors for non-invasive or minimally invasive routes of administration at a doctor’s office or potentially in the patient’s home by a healthcare professional. Our goal is to develop easy to use medicines to dramatically improve the lives of patients living with debilitating diseases. Our innovative technology platform is supported by in-house, commercial scale current good manufacturing practices ("cGMP") manufacturing capabilities. Liquidity As of March 31, 2022, the Company had an accumulated deficit of $190.7 million. With the net proceeds raised from its public and private securities offerings the Company believes that its cash, cash equivalents and short-term investments of approximately $434.6 million as of March 31, 2022 will be sufficient to allow the Company to fund its planned operations for at least the next 12 months from the date of this Quarterly Report on Form 10-Q. As the Company continues to incur losses, a transition to profitability is dependent upon the successful development, approval and commercialization of its product candidates and the achievement of a level of revenues adequate to support the Company’s cost structure. The Company may never achieve profitability and unless and until it does, the Company will continue to need to raise additional capital or obtain financing from other sources. Management intends to fund future operations through the sale of equity and debt financings and may also seek additional capital through arrangements with strategic partners or other sources. There can be no assurance that additional funding will be available on terms acceptable to the Company, if at all. The Company is subject to risks common to companies in the biotechnology industry, including but not limited to the failure of product candidates in clinical and preclinical studies, the development of competing product candidates or other technological innovations by competitors, dependence on key personnel, protection of proprietary technology, compliance with government regulations and the ability to c ommercialize product candidates.

Summary of Significant Accounti

Summary of Significant Accounting Policies	3 Months Ended
	Mar. 31, 2022
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	Summary of Significant Accounting Policies Basis of Presentation The accompanying unaudited interim condensed financial statements have been prepared in conformity with generally accepted accounting principles in the United States of America (“GAAP”), as found in the Accounting Standards Codification (“ASC”), the Accounting Standards Update (“ASU”) of the Financial Accounting Standards Board (“FASB”), and the rules and regulations of the US Securities and Exchange Commission (“SEC”). In the opinion of management, all adjustments, which consist of all normal recurring adjustments necessary for a fair presentation of the Company's financial position and results of operations for the interim periods ended March 31, 2022 and 2021, are reflected in the interim condensed consolidated financial statements. All intercompany balances and transactions have been eliminated in consolidation. Certain prior period amounts have been reclassified to conform to the current period presentation. The reclassified amounts have no impact on the Company’s previously reported financial position or results of operation. The results of operations for the interim periods are not necessarily indicative of the results of operations to be expected for the full year. These unaudited interim condensed financial statements should be read in conjunction with the Company’s audited consolidated financial statements and the notes thereto included in the Company’s Annual Report on Form 10-K for the fiscal year ended December 31, 2021, as filed with the SEC on February 28, 2022. Risks and Uncertainties The novel coronavirus ("COVID-19") pandemic has resulted, and is likely to continue to result, in significant national and global economic uncertainty and may adversely affect our business. The Company is continuing to actively monitor the impact of the COVID-19 pandemic and the related effects on its financial condition, liquidity, operations, suppliers, industry, and workforce. However, the full extent, consequences, and duration of the COVID-19 pandemic and the resulting impact on the Company cannot currently be predicted. The Company will continue to evaluate the impact that these events could have on the operations, financial position, and the results of operations and cash flows during fiscal year 2022. Use of Estimates The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts in the condensed consolidated financial statements and accompanying notes. Actual results could materially differ from those estimates. Management considers many factors in selecting appropriate financial accounting policies and controls, and in developing the estimates and assumptions that are used in the preparation of these financial statements. Management must apply significant judgment in this process. In addition, other factors may affect estimates, including expected business and operational changes, sensitivity and volatility associated with the assumptions used in developing estimates, and whether historical trends are expected to be representative of future trends. The estimation process often may yield a range of potentially reasonable estimates of the ultimate future outcomes and management must select an amount that falls within that range of reasonable estimates. This process may result in actual results differing materially from those estimated amounts used in the preparation of the financial statements. Estimates are used in the following areas including stock-based compensation expense, accrued expenses, the fair value of financial instruments, the incremental borrowing rate for lease liabilities, and the valuation allowance included in the deferred income tax calculation. Segment and Geographical Information Operating segments are defined as components of an enterprise about which separate discrete information is available for evaluation by the chief operating decision maker, or decision-making group, in deciding how to allocate resources and in assessing performance. The Company and the Company’s chief operating decision maker view the Company’s operations and manage its business in one operating segment, which is the business of developing and commercializing pharmaceuticals. Concentrations of Credit Risk and Off-Balance Sheet Risk Financial instruments that potentially subject the Company to credit risk consist of cash, cash equivalents and investments. The Company’s policy is to invest its cash, cash equivalents and investments in money market funds, certificates of deposit, corporate bonds, commercial paper, government agency securities and various other bank deposit accounts. The counterparties to the agreements relating to the Company’s investments consist of financial institutions of high credit standing. The Company is exposed to credit risk in the event of default by the financial institutions to the extent amounts recorded on the balance sheets are in excess of insured limits. The Company has not experienced any credit losses in such accounts and does not believe it is exposed to any significant credit risk on these funds. The Company has no financial instruments with off-balance sheet risk of loss. Cash, Cash Equivalents and Investments Cash and cash equivalents consist of money market funds and bank deposits. Cash equivalents are defined as short-term, highly liquid investments with original maturities of 90 days or less at the date of purchase. Investments with maturities of greater than 90 days but less than one year are classified as short-term investments on the consolidated balance sheets and consist of commercial paper, corporate bonds, and government agency securities. Investments with maturities of greater than one year are classified as long-term investments on the consolidated balance sheets and consist of corporate bonds and government agency securities. Accrued interest on corporate bonds and government agency securities are also classified as short-term investments. As our entire investment portfolio is considered available for use in current operations, we classify all investments as available-for-sale securities. Available-for-sale securities are carried at fair value, with unrealized gains and losses reported in accumulated other comprehensive loss, which is a separate component of stockholders’ equity in the consolidated balance sheets. Fair Value of Financial Instruments Fair value is defined as the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date. There is a three-level hierarchy that prioritizes the inputs used in determining fair value by their reliability and preferred use, as follows: • Level 1 — Valuations based on quoted prices in active markets for identical assets or liabilities. • Level 2 — Valuations based on quoted prices in active markets for similar assets and liabilities, quoted prices for identical or similar assets or liabilities in inactive markets, or other inputs that are observable or can be corroborated by observable market data. • Level 3 — Valuations based on inputs that are both significant to the fair value measurement and unobservable. To the extent that a valuation is based on models or inputs that are less observable, or unobservable in the market, the determination of fair value requires more judgment. Accordingly, the degree of judgment exercised by the Company in determining fair value is greatest for instruments categorized within Level 3. A financial instrument’s level within the fair value hierarchy is based on the lowest level of any input that is significant to the fair value measurement. There have been no significant changes to the valuation methods utilized by the Company during the periods presented. There have been no transfers between Level 1, Level 2, and Level 3 in any periods presented. The carrying amounts of financial instruments consisting of cash and cash equivalents, investments, prepaid expenses and other current assets, accounts payable, accrued expenses and other current liabilities included in the Company’s financial statements, are reasonable estimates of fair value, primarily due to their short maturities. Marketable securities are classified as long-term investments if the Company has the ability and intent to hold them and such holding period is longer than one year. The Company classifies all of its investments as available-for-sale. Our available-for-sale, short-term and long-term investments, which consist of, commercial paper, corporate bonds, and government agency securities are considered to be Level 2 valuations. The fair value of Level 2 financial assets is determined using inputs that are observable in the market or can be derived principally from or corroborated by observable market data, such as pricing for similar securities, recently executed transactions, cash flow models with yield curves, and benchmark securities. In addition, Level 2 financial instruments are valued using comparisons to like-kind financial instruments and models that use readily observable market data as their basis. Property and Equipment, net Property and equipment, net, is stated at cost, less accumulated depreciation. Maintenance and repairs that do not improve or extend the lives of the respective assets are expensed to operations as incurred, while costs of major additions and betterments are capitalized. Upon disposal, the related cost and accumulated depreciation is removed from the accounts and any resulting gain or loss is included in the results of operations. Depreciation is recorded using the straight-line method over the estimated useful lives of the respective assets, which are as follows: Computer equipment and software 3 - 7 years Lab equipment 3 - 7 years Furniture and fixtures 3 - 7 years Leasehold improvement lesser of remaining useful life or remaining lease term Construction in progress ("CIP") is not depreciated until the asset is placed in service. Impairment of Long-Lived Assets The Company evaluates long-lived assets for potential impairment when events or changes in circumstances indicate the carrying value of the assets may not be recoverable. An impairment loss would be recognized when estimated future cash flows expected to result from the use of the asset and its eventual disposition are less than the carrying amount of the asset. The Company has not recognized any impairment losses for the three months ended March 31, 2022 and 2021. Leases The Company accounts for its lease agreements in accordance with FASB ASC Topic 842, Leases ("ASC 842"). Right-of-use lease assets represent our right to use an underlying asset during the lease term and the lease obligations represent our commitment to make lease payments arising from the lease. Right-of-use lease assets and obligations are recognized based on the present value of remaining lease payments over the lease term. As the Company’s lease agreements do not provide an implicit rate and as the Company does not have any external borrowings, we have used an estimated incremental borrowing rate based on the information available at lease commencement in determining the present value of lease payments. Operating lease expense is recognized on a straight-line basis over the lease term. Variable lease expense is recognized in the period in which the obligation for the payment is incurred. In addition, the Company also has made an accounting policy election to exclude leases with an initial term of twelve months or less from its balance sheet and to account for lease and non-lease components of its operating leases as a single component. For lease arrangements where it has been determined that the Company has control over an asset that is under construction and is thus considered the accounting owner of the asset during the construction period, the Company records a construction in progress asset and corresponding financial obligation on the condensed consolidated balance sheet. Once the construction is complete, an assessment is performed to determine whether the lease meets certain "sale-leaseback" criteria. If the sale-leaseback criteria are determined to be met, the Company will remove the asset and related financial obligation from the condensed consolidated balance sheet and treat the lease as either an operating or finance lease based on our assessment of the guidance. If, upon completion of construction, the project does not meet the "sale-leaseback" criteria, the lease will be treated as a financing obligation and the Company will depreciate the asset over its estimated useful life for financial reporting purposes once the asset has been placed into service. Research and Development Expenses Research and development costs are charged to expense as incurred in performing research and development activities. These costs include employee compensation costs, facilities and overhead, preclinical and clinical activities, related clinical manufacturing costs, contract management services, regulatory and other related costs. The Company estimates contract research and clinical trials materials manufacturing expenses based on the services performed pursuant to contracts with research organizations and manufacturing organizations that manufacture materials used in the Company’s ongoing preclinical and clinical studies. Non-refundable advanced payments for goods or services to be received in the future for use in research and development activities are deferred and capitalized. The capitalized amounts are expensed as the related goods are delivered or the services are performed. In accruing service fees, the Company estimates the time period over which services will be performed and the level of effort to be expended in each period. These estimates are based on communications with the third party service providers and the Company’s estimates of accrued expenses using information available at each balance sheet date. If the actual timing of the performance of services or the level of effort varies from the estimate, the Company will adjust the accrual accordingly. Stock-Based Compensation Expense The Company applies the fair value recognition provisions of Financial Accounting Standards Board Accounting Standards Codification, or ASC, Topic 718, Compensation—Stock Compensation ("ASC 718"), to account for stock-based compensation. Compensation costs related to stock options granted is based on the estimated fair value of the awards on the date of grant. ASC 718 requires all stock-based payments, including grants of stock options and restricted stock, to be recognized in the statements of operations based on their grant-date fair values. Compensation expense is recognized on a straight-line basis based on the grant-date fair value over the associated service period of the award, which is generally the vesting term. The Company estimates the fair value of its stock options using the Black-Scholes option pricing model, which requires the input of subjective assumptions, including: (i) the expected stock price volatility; (ii) the expected term of the award; (iii) the risk-free interest rate; and (iv) expected dividends. Once the Company's own sufficient historical volatility data was obtained, the Company eliminated the use of a representative peer group and uses only its own historical volatility data in its estimate of expected volatility. The Company estimates the expected term of its stock options using the “simplified” method, whereby the expected term equals the arithmetic mean of the vesting term and the original contractual term of the option. The risk-free interest rates are based on US Treasury securities with a maturity date commensurate with the expected term of the associated award. The Company has never paid and does not expect to pay dividends in the foreseeable future. The Company accounts for forfeitures as they occur. Stock-based compensation expense recognized in the financial statements is based on awards for which service conditions are expected to be satisfied. Comprehensive Loss Comprehensive loss is defined as the change in equity during a period from transactions from non-owner sources. Unrealized gains or losses on available-for-sale securities is a component of other comprehensive gains or losses and is presented net of taxes. We have not recorded any reclassifications from other comprehensive gains or losses to net loss during any period presented. Recent Accounting Pronouncements ASU No. 2020-08, Codification Improvements to Subtopic 310-20, Receivables - Nonrefundable Fees and Other Costs In October 2020, the FASB issued ASU 2020-08, Codification Improvements to Subtopic 310-20, Receivables - Nonrefundable Fees and Other Costs ("ASU 2020-08") to provide further clarification and update the previously issued guidance in ASU 2017-08, Receivables - Nonrefundable Fees and Other Costs (Subtopic 310-20: Premium Amortization on Purchased Callable Debt Securities) ("ASU 2017-08"). ASU 2017-08 shortened the amortization period for certain callable debt securities purchased at a premium by requiring that the premium be amortized to the earliest call date. ASU 2020-08 requires that at each reporting period, to the extent that the amortized cost of an individual callable debt security exceeds the amount repayable by the issuer at the next call date, the excess premium shall be amortized to the next call date. The new standard was effective beginning January 1, 2021 and should be applied on a prospective basis as of the beginning of the period of adoption for existing or newly purchased callable debt securities. The adoption of ASU 2020-08 did not have a material impact on the Company's financial position or results of operations upon adoption.

Net Loss Per Share Attributable

Net Loss Per Share Attributable to Common Stockholders	3 Months Ended
	Mar. 31, 2022
Earnings Per Share [Abstract]
Net Loss Per Share Attributable to Common Stockholders	Net Loss Per Share Attributable to Common Stockholders Basic net loss per share attributable to common stockholders is calculated by dividing net loss attributable to common stockholders by the weighted average shares outstanding during the period, without consideration for common stock equivalents. Diluted net loss per share attributable to common stockholders is computed by dividing the net loss by the weighted-average number of shares of common stock and common share equivalents outstanding for the period. Common share equivalents consist of common stock issuable upon exercise of stock options and vesting of restricted stock awards. There were 3,226,962 and 1,423,540 common share equivalents outstanding as of March 31, 2022 and 2021, respectively, in the form of stock options and unvested restricted stock awards, that have been excluded from the calculation of diluted net loss per common share as their effect would be anti-dilutive for all periods presented. Three Months Ended 2022 2021 (In thousands, except shares and per share data) (Unaudited) Numerator: Net loss per common share $ (49,965) $ (15,812) Denominator: Weighted-average basic and diluted common shares 25,114,453 21,253,508 Basic and diluted net loss per $ (1.99) $ (0.74)

Fair Value Instruments

Fair Value Instruments	3 Months Ended
	Mar. 31, 2022
Fair Value Disclosures [Abstract]
Fair Value Instruments	Fair Value Instruments The following tables show the Company’s cash, cash equivalents and available-for-sale securities by significant investment category as of March 31, 2022 and December 31, 2021, respectively (in thousands): March 31, 2022 (unaudited) Amortized Cost Gross Gross Aggregate Fair Cash and Cash Short-term Marketable Securities (1) Long-term Marketable Securities (2) Level 1: Cash and cash equivalents $ 269,303 $ — $ — $ 269,303 $ 269,303 $ — $ — Subtotal 269,303 — — 269,303 269,303 — — Level 2: Commercial paper 39,476 — (37) 39,439 — 39,439 — Corporate bonds 106,741 2 (724) 106,019 — 81,961 24,058 U.S. government agency securities 53,650 — (440) 53,210 — 43,929 9,281 Subtotal 199,867 2 (1,201) 198,668 — 165,329 33,339 Total $ 469,170 $ 2 $ (1,201) $ 467,971 $ 269,303 $ 165,329 $ 33,339 December 31, 2021 Amortized Cost Gross Gross Aggregate Fair Cash and Cash Short-term Marketable Securities (1) Long-term Marketable Securities (2) Level 1: Cash and cash equivalents $ 341,246 $ — $ — $ 341,246 $ 341,246 $ — $ — Subtotal 341,246 — — 341,246 341,246 — — Level 2: Commercial paper 40,469 1 (4) 40,466 — 40,466 — Corporate bonds 83,300 10 (114) 83,196 — 35,768 47,428 U.S. government agency securities 37,621 — (62) 37,559 — 20,616 16,943 Subtotal 161,390 11 (180) 161,221 — 96,850 64,371 Total $ 502,636 $ 11 $ (180) $ 502,467 $ 341,246 $ 96,850 $ 64,371 (1) The Company’s short-term marketable securities mature in one year or less. (2) The Company's long-term marketable securities mature between one year and two years. See Note 2 to these unaudited condensed consolidated financial statements for additional discussion regarding the Company’s fair value measurements.

Balance Sheet Components

Balance Sheet Components	3 Months Ended
	Mar. 31, 2022
Balance Sheet Related Disclosures [Abstract]
Balance Sheet Components	Balance Sheet Components Property and Equipment, Net Property and equipment, net consist of the following (in thousands): March 31, December 31, (Unaudited) Construction in progress $ 128,933 $ 104,340 Leasehold improvements 5,736 5,723 Furniture and fixtures 900 891 Computer equipment and software 96 85 Laboratory and manufacturing equipment 5,938 5,530 Total property and equipment 141,603 116,569 Accumulated depreciation and amortization (4,676) (4,214) Property and equipment, net $ 136,927 $ 112,355 Depreciation expense was $462 thousand and $438 thousand for the three months ended March 31, 2022 and 2021, respectively. Accrued Expenses and Other Current Liabilities Accrued expenses and other current liabilities consisted of the following (in thousands): March 31, December 31, (Unaudited) Accrued preclinical and clinical expenses $ 2,647 $ 1,602 Accrued professional fees 4,168 2,011 Accrued payroll and benefits 1,560 2,882 Accrued taxes 149 83 Accrued construction in progress 17,097 9,606 Accrued financing costs 54 26 Accrued litigation settlement 25,000 — Other current liabilities 142 87 Total $ 50,817 $ 16,297

Commitments and Contingencies

Commitments and Contingencies	3 Months Ended
	Mar. 31, 2022
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Commitments and Contingencies Significant Contracts and Agreements Lease Agreements On May 26, 2016, the Company signed an operating lease for laboratory and office space that commenced in June 2016 and expired on October 31, 2017 (the “2016 Lease”). The 2016 Lease has been amended several times to increase the area leased, which currently consists of approximately 47,000 square feet and includes the commercial scale cGMP-compliant manufacturing facility, ANCORIS. As a result of the lease amendments, the lease expiration date was extended to October 31, 2031. On December 26, 2019, we entered into a lease agreement for our second commercial gene therapy facility ("ASTRA") in the Pittsburgh, Pennsylvania area ("ASTRA lease") with Northfield I, LLC (the "Landlord", "Northfield", or "Lessor") with an initial lease term that expired on October 31, 2035. The ASTRA lease contained an option ("Purchase Option") to purchase the building, related improvements and take corresponding assignment of the Landlord's rights under its existing Ground Lease (the "Ground Lease"). A cash contribution in the amount of $2.4 million was paid to escrow on January 21, 2020. The contribution was intended to reduce the amount of the building construction costs and had the effect of reducing the base rental rate of the lease and as such, was recorded as prepaid rent in the consolidated balance sheet at the time of payment. On October 5, 2020, the Company was provided with notice that the initial delivery conditions of the building had been met, including completion of the building shell, interior slab, and exterior doors, and on October 15, 2020, the Company gave the Landlord notice of its intent to purchase ASTRA for approximately $9.4 million, subject to the parties entering into a commercially reasonable purchase and sale agreement. As a result of the Company's ability to exercise its option to purchase ASTRA, the Company obtained control over the construction in progress of ASTRA as of October 5, 2020. The Company recorded a $10.0 million CIP asset and a corresponding build to suit lease liability related to the costs incurred by the Landlord, offset by the previous cash contribution of $2.4 million. On January 29, 2021, the Company entered into a Purchase and Sale Agreement ("PSA") for ASTRA with Northfield related to the purchase option exercised by the Company on October 15, 2020, for a purchase price of $9.4 million. The Company held approximately $1.5 million on deposit with Northfield under the existing lease agreement and applied this deposit as a credit against the purchase price at closing. On February 1, 2021, Northfield delivered the space as substantially complete and made the space available for access by the Company, thus triggering lease commencement. As a result, the Company concluded that this transaction did not qualify for sale-leaseback accounting because it did not meet the definition of a sale. As control did not transfer to the Lessor at lease commencement, the transaction continued to be accounted for as construction in progress and a financing obligation. On March 5, 2021, the purchase closed and the Company determined that reclassification of the construction in progress to buildings and leasehold improvements was not appropriate as the interior of the building was not yet ready for its intended use. The building continues to be held under construction in progress as of March 31, 2022. The interior of the building is currently under construction and is expected to be completed and validated in 2022. From construction completion to the closing of the purchase, the Company recognized interest expense to accrete the financial obligation to a balance that equaled the cash consideration that was paid upon the close of purchase. For more information about the expected construction costs associated with ASTRA, see "ASTRA Contractual Obligations" below. As part of the transaction, the Company also became the accounting owner of the Ground Lease, due to obtaining control over ASTRA, and recorded the applicable operating right-of-use asset and corresponding lease liability as of October 5, 2020. When the PSA was finalized, the Company took assignment of the Lessor's Ground Lease, in accordance with the Purchase Option, of which lease payments are based on annual payments of $82 thousand, and are subject to a cumulative 10% escalation clause every 5 years through 2071. On December 15, 2021, the Company entered into a 3 year lease agreement for our Boston, Massachusetts office (the "Boston Lease") location that commenced in January 2022 and expires in January 2025. As of March 31, 2022, future minimum commitments under the Company’s operating leases were as follows (in thousands): Operating 2022 (remaining nine months) $ 1,115 2023 1,510 2024 1,539 2025 1,277 2026 1,277 Thereafter 12,063 Future minimum operating lease payments $ 18,781 Less: Interest 9,487 Present value of lease liability $ 9,294 Supplemental condensed consolidated balance sheet information related to leases is as follows: (unaudited) March 31, 2022 December 31, 2021 Operating leases: Right-of-use assets $ 8,453 $ 7,228 Current portion of lease liability 1,411 1,041 Lease liability 7,883 6,983 Total lease liability $ 9,294 $ 8,024 Weighted average remaining lease term, in years 13.0 14.4 Weighted average discount rate 9.3 % 9.5 % The Company recorded operating lease costs of $409 thousand and $218 thousand for the three months ended March 31, 2022 and 2021, respectively, and variable lease costs of $49 thousand and $37 thousand for the three months ended March 31, 2022 and 2021, respectively. Agreements with Contract Manufacturing Organizations and Contract Research Organizations The Company enters into various agreements in the normal course of business with Contract Research Organizations ("CROs"), Contract Manufacturing Organizations ("CMOs") and other third parties for preclinical research studies, clinical trials and testing and manufacturing services. The agreements with CMOs relate to the manufacturing of sterile gel that is mixed with in-house produced vectors as part of the final drug product applied in certain of our clinical trials. These agreements may also include research and development activities, storage, packaging, labeling, and/or testing of our preclinical and clinical-stage products. The Company is obligated to make milestone payments under certain of these agreements. The estimated remaining commitment as of March 31, 2022 under these agreements is approximately $3.1 million. The Company may also be responsible for the payment of a monthly service fee for project management services for the duration of any agreements. The Company has incurred expenses under these agreements of $1.8 million for each of the three months ended March 31, 2022 and 2021. Commercial Preparedness Activities The Company has contracted with various third parties to facilitate, coordinate and perform agreed upon commercial preparedness and market research activities relating to our lead product candidate. These contracts typically call for the payment of fees for services upon the achievement of certain milestones. The estimated remaining commitment as of March 31, 2022 is $4.3 million. The Company has incurred expenses under these activities of $3.1 million and $1.3 million for the three months ended March 31, 2022 and 2021, respectively. ASTRA Contractual Obligations The Company has contracted with various third parties to construct our second cGMP facility, ASTRA. Additionally, we have entered into various non-cancellable purchase agreements for long-lead materials to help avoid potential schedule disruptions or material shortages. These contracts typically call for the payment of fees for services or materials upon the achievement of certain milestones. The estimated remaining commitment as of March 31, 2022 is $20.2 million. The Company has included costs incurred to-date associated with ASTRA within construction in progress as of March 31, 2022. On June 30, 2021, the Company entered into a Standard Form of Contract for Construction and the corresponding General Conditions of the Contract for Construction (collectively, the “Agreement”) with The Whiting-Turner Contracting Company (“Whiting-Turner”), pursuant to which Whiting-Turner is constructing and managing the construction of ASTRA. Subject to certain conditions in the Agreement, the Company will pay Whiting-Turner a contract price consisting of the cost of work plus a fee equal to 1.75% of the cost of work. Effective September 13, 2021, the Company entered into a guaranteed maximum price amendment (the "Amendment") to the Agreement to set forth the guaranteed maximum price, as well as the date by which Whiting-Turner is to achieve Substantial Completion (as defined in the Agreement). Under the Amendment, the guaranteed maximum price to be paid by the Company is $82.3 million, subject to certain additions and deductions by change orders as provided by the Agreement. Whiting-Turner’s work under the Agreement represents a portion of the work necessary to complete construction of the ASTRA facility and, therefore the date of Substantial Completion of Whiting-Turner’s work under the Agreement does not equate to the date of completion of ASTRA. The guaranteed maximum price under the Agreement constitutes only a portion of the total estimated cost of building and equipping ASTRA. Legal Proceedings On May 1, 2020, a complaint was filed against us in the United States District Court for the Western District of Pennsylvania by PeriphaGen, Inc. ("PeriphaGen"), which also named our Chief Executive Officer and President, R&D, Krish Krishnan and Suma Krishnan, respectively. The complaint alleged breach of contract and misappropriation of trade secrets, which secrets the plaintiff asserted were used to develop our product candidates, including the vector backbones, and our STAR-D platform. We answered the complaint on June 26, 2020 by denying the allegations and brought a counterclaim asking the court to declare that we did not misappropriate PeriphaGen’s trade secrets or confidential information, and to further declare that we are the rightful and sole owner of our product candidates and STAR-D platform. In addition, we filed a third-party complaint against two principals of PeriphaGen, James Wechuck and David Krisky, alleging breach of contract and seeking contribution and indemnification from them in the event PeriphaGen is awarded damages. On March 9, 2022, the court officially ordered the parties to attend mediation on March 11, 2022. During the course of the mediation process, the parties were able to exchange information, allowing the parties to value their positions. On March 12, 2022, we entered into a binding term sheet. In consideration of settling the dispute, the acquisition of certain PeriphaGen assets, and the grant of a license by PeriphaGen for dermatological applications, Krystal made a payment of $25.0 million on April 28, 2022. Upon approval of Krystal’s first product by the U.S. Food and Drug Administration ("FDA"), Krystal will pay an additional $12.5 million, followed by three additional $12.5 million contingent milestone payments upon reaching $100.0 million in total cumulative sales, $200.0 million in total cumulative sales and $300.0 million in total cumulative sales. As defined in the settlement agreement, cumulative sales shall include all revenue from sales of Krystal products by Krystal and its affiliates and licensees, as reported by Krystal in its annual Form 10-K filings. If all milestones are achieved, the total consideration for settling the dispute, acquiring certain assets, and granting of a license from PeriphaGen will be $75.0 million. The final settlement agreement was signed on April 28, 2022, and, because we deemed settlement to be probable as of the balance sheet date, we have recorded an accrued liability equal to the settlement of $25.0 million under accrued expenses and other current liabilities on the condensed consolidated balance sheet and under litigation settlement expense on the condensed consolidated statements of operations. The additional contingent milestone payments were not deemed probable due to uncertainty in the achievement of these milestones as of March 31, 2022, and therefore no additional accrual has been recorded. The Company has received $768 thousand of insurance proceeds during the three months ended March 31, 2022 and we have recorded an additional $301 thousand as a receivable within prepaid expenses and other current assets on the condensed consolidated balance sheet as management determined that the amount was probable of collection relating to legal defense costs and expenses associated with the PeriphaGen litigation. The reimbursements have been recorded as an offset to our legal fees included in general and administrative expenses on the condensed consolidated statements of operations and within operating activities on the condensed consolidated statements of cash flows.

Capitalization

Capitalization	3 Months Ended
	Mar. 31, 2022
Equity [Abstract]
Capitalization	Capitalization Sale of Common Stock On December 3, 2021, the Company completed a public offering of 2,866,667 shares of its common stock, including 200,000 shares purchased by the underwriters, at $75.00 per share. Net proceeds to the Company from the offering were $201.9 million after deducting underwriting discounts and commissions of approximately $12.9 million, and other offering expenses payable by the Company of $227 thousand. On February 1, 2021, the Company completed a public offering of 2,211,538 shares of its common stock, including 288,461 shares purchased by the underwriters, at $65.00 per share. Net proceeds to the Company from the offering were $134.9 million after deducting underwriting discounts and commissions of approximately $8.6 million, and other offering expenses payable by the Company of $198 thousand. On December 31, 2020, the Company entered into a sales agreement (the "Sales Agreement") with Cowen and Company, LLC ("Cowen") with respect to an at-the-market equity offering program ("ATM Program"), under which Cowen will act as the Company's agent and/or principal and may issue and sell from time to time, during the term of the Sales Agreement, shares of our common stock, having an aggregate offering price up to $150.0 million ("Placement Shares"). Related offering expenses payable by the Company were $172 thousand. The issuance and sale of the Placement Shares by the Company under the Sales Agreement will be made pursuant to the Company's effective "shelf" registration statement on Form

Stock-Based Compensation

Stock-Based Compensation	3 Months Ended
	Mar. 31, 2022
Share-based Payment Arrangement [Abstract]
Stock-Based Compensation	Stock-Based Compensation Stock Options Options granted to employees vest ratably over four-year periods and stock options granted to directors of the company vest ratably over one year to four-year periods. Stock options have a life of ten years. The Company granted 1,179,500 and 502,450 stock options to employees and directors of the Company during the three months ended March 31, 2022 and 2021, respectively. The following table summarizes the Company’s stock option activity: Stock Weighted- Weighted- Aggregate Intrinsic Value (In thousands) (1) Outstanding at December 31, 2021 2,043,179 $ 57.00 9.0 $ 31,331 Granted 1,179,500 $ 62.53 Exercised (1,475) $ 37.34 Cancelled or forfeited (68,342) $ 61.24 Expired — $ — Outstanding at March 31, 2022 3,152,862 $ 58.99 9.1 $ 30,364 Exercisable at March 31, 2022 439,954 $ 44.52 7.6 $ 10,929 (1) Aggregate intrinsic value represents the difference between the closing stock price of our common stock on March 31, 2022 and the exercise price of outstanding in-the-money options. The total intrinsic value (the amount by which the fair market value exceeds the exercise price) of stock options exercised during the three months ended March 31, 2022 and 2021 was $36 thousand and $808 thousand, respectively. The weighted-average grant-date fair value per share of options granted to employees and directors during the three months ended March 31, 2022 and 2021 was $43.09 and $50.04, respectively. There was $101.1 million of unrecognized stock-based compensation expense related to employees' and directors’ option awards that is expected to be recognized over a weighted-average period of 3.4 years as of March 31, 2022. The Company has recorded aggregate stock-based compensation expense related to the issuance of stock option awards in the condensed consolidated statements of operations for the three months ended March 31, 2022 and 2021 as follows (in thousands): Three Months Ended March 31, 2022 2021 (unaudited) Research and development $ 1,368 $ 516 General and administrative 4,582 1,615 Total stock-based compensation $ 5,950 $ 2,131 We capitalize the portion of stock-based compensation that relates to work performed on the construction of new buildings. There was $141 thousand and $37 thousand of stock-based compensation that was capitalized in the three months ended March 31, 2022 and 2021, respectively. The Company recorded stock-based compensation expense of $6.0 million and $2.1 million for the three months ended March 31, 2022 and 2021, respectively. The fair value of options was estimated at the date of grant using the Black-Scholes valuation model with the following weighted-average assumptions for the three months ended March 31, 2022 and 2021: Three Months Ended March 31, 2022 2021 Expected stock price volatility 78 % 73 % Expected term of the award (years) 6.24 6.22 Risk-free interest rate 1.79 % 1.00 % Weighted average exercise price $ 62.53 $ 77.46 Forfeiture rate — % — % Restricted Stock Awards Restricted stock awards ("RSAs") granted to employees vest ratably over a four-year period. The Company granted zero and 98,800 RSAs to employees of the Company during the three months ended March 31, 2022 and 2021, respectively. Number of Shares Weighted Average Non-vested RSAs as of December 31, 2021 98,800 $ 78.89 Granted — $ — Vested (14,321) $ 78.89 Forfeited (10,379) $ 78.89 Non-vested RSAs as of March 31, 2022 74,100 $ 78.89 There was $5.7 million of unrecognized stock-based compensation expense related to employees’ awards that is expected to be recognized over a weighted-average period of 2.9 years as of March 31, 2022. The Company recorded stock-based compensation expense related to RSAs of $480 thousand and $182 thousand for the three months ended March 31, 2022 and 2021, respectively, within general and administrative expenses in the accompanying condensed consolidated statements of operations (in thousands): Three Months Ended March 31, 2022 2021 (unaudited) General and administrative $ 480 $ 182 Total stock-based compensation $ 480 $ 182 Shares remaining available for grant under the Company’s stock incentive plan were 1,028,815, with a sublimit for incentive stock options of 26,546, at March 31, 2022.

Subsequent Events

Subsequent Events	3 Months Ended
	Mar. 31, 2022
Subsequent Events [Abstract]
Subsequent Events	Subsequent Events On April 28, 2022, the Company entered into a final settlement agreement and paid PeriphaGen an upfront payment of $25.0 million for: (i) the resolution of all claims in the trade secret litigation with PeriphaGen, Inc.; (ii) the acquisition of certain PeriphaGen assets, and (iii) the grant of a license by PeriphaGen for dermatological applications. On April 5, 2022, pursuant to an inbound request, the Company issued and sold 434,782 shares of common stock at a weighted average price of $69.00 per share, under it's ATM Program, for net proceeds of $29.1 million after deducting underwriting discounts and commissions.

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	3 Months Ended
	Mar. 31, 2022
Accounting Policies [Abstract]
Basis of Presentation	Basis of Presentation The accompanying unaudited interim condensed financial statements have been prepared in conformity with generally accepted accounting principles in the United States of America (“GAAP”), as found in the Accounting Standards Codification (“ASC”), the Accounting Standards Update (“ASU”) of the Financial Accounting Standards Board (“FASB”), and the rules and regulations of the US Securities and Exchange Commission (“SEC”). In the opinion of management, all adjustments, which consist of all normal recurring adjustments necessary for a fair presentation of the Company's financial position and results of operations for the interim periods ended March 31, 2022 and 2021, are reflected in the interim condensed consolidated financial statements. All intercompany balances and transactions have been eliminated in consolidation. Certain prior period amounts have been reclassified to conform to the current period presentation. The reclassified amounts have no impact on the Company’s previously reported financial position or results of operation. The results of operations for the interim periods are not necessarily indicative of the results of operations to be expected for the full year. These unaudited interim condensed financial statements should be read in conjunction with the Company’s audited consolidated financial statements and the notes thereto included in the Company’s Annual Report on Form 10-K for the fiscal year ended December 31, 2021, as filed with the SEC on February 28, 2022.
Risks and Uncertainties	Risks and Uncertainties The novel coronavirus ("COVID-19") pandemic has resulted, and is likely to continue to result, in significant national and global economic uncertainty and may adversely affect our business. The Company is continuing to actively monitor the impact of the COVID-19 pandemic and the related effects on its financial condition, liquidity, operations, suppliers, industry, and workforce. However, the full extent, consequences, and duration of the COVID-19 pandemic and the resulting impact on the Company cannot currently be predicted. The Company will continue to evaluate the impact that these events could have on the operations, financial position, and the results of operations and cash flows during fiscal year 2022.
Use of Estimates	Use of Estimates The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts in the condensed consolidated financial statements and accompanying notes. Actual results could materially differ from those estimates. Management considers many factors in selecting appropriate financial accounting policies and controls, and in developing the estimates and assumptions that are used in the preparation of these financial statements. Management must apply significant judgment in this process. In addition, other factors may affect estimates, including expected business and operational changes, sensitivity and volatility associated with the assumptions used in developing estimates, and whether historical trends are expected to be representative of future trends. The estimation process often may yield a range of potentially reasonable estimates of the ultimate future outcomes and management must select an amount that falls within that range of reasonable estimates. This process may result in actual results differing materially from those estimated amounts used in the preparation of the financial statements. Estimates are used in the following areas including stock-based compensation expense, accrued expenses, the fair value of financial instruments, the incremental borrowing rate for lease liabilities, and the valuation allowance included in the deferred income tax calculation.
Segment and Geographical Information	Segment and Geographical InformationOperating segments are defined as components of an enterprise about which separate discrete information is available for evaluation by the chief operating decision maker, or decision-making group, in deciding how to allocate resources and in assessing performance. The Company and the Company’s chief operating decision maker view the Company’s operations and manage its business in one operating segment, which is the business of developing and commercializing pharmaceuticals.
Concentrations of Credit Risk and Off-Balance Sheet Risk	Concentrations of Credit Risk and Off-Balance Sheet Risk Financial instruments that potentially subject the Company to credit risk consist of cash, cash equivalents and investments. The Company’s policy is to invest its cash, cash equivalents and investments in money market funds, certificates of deposit, corporate bonds, commercial paper, government agency securities and various other bank deposit accounts. The counterparties to the agreements relating to the Company’s investments consist of financial institutions of high credit standing. The Company is exposed to credit risk in the event of default by the financial institutions to the extent amounts recorded on the balance sheets are in excess of insured limits. The Company has not experienced any credit losses in such accounts and does not believe it is exposed to any significant credit risk on these funds. The Company has no financial instruments with off-balance sheet risk of loss.
Cash, Cash Equivalents and Investments	Cash, Cash Equivalents and Investments Cash and cash equivalents consist of money market funds and bank deposits. Cash equivalents are defined as short-term, highly liquid investments with original maturities of 90 days or less at the date of purchase. Investments with maturities of greater than 90 days but less than one year are classified as short-term investments on the consolidated balance sheets and consist of commercial paper, corporate bonds, and government agency securities. Investments with maturities of greater than one year are classified as long-term investments on the consolidated balance sheets and consist of corporate bonds and government agency securities. Accrued interest on corporate bonds and government agency securities are also classified as short-term investments.
Fair Value of Financial Instruments	Fair Value of Financial Instruments Fair value is defined as the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date. There is a three-level hierarchy that prioritizes the inputs used in determining fair value by their reliability and preferred use, as follows: • Level 1 — Valuations based on quoted prices in active markets for identical assets or liabilities. • Level 2 — Valuations based on quoted prices in active markets for similar assets and liabilities, quoted prices for identical or similar assets or liabilities in inactive markets, or other inputs that are observable or can be corroborated by observable market data. • Level 3 — Valuations based on inputs that are both significant to the fair value measurement and unobservable. To the extent that a valuation is based on models or inputs that are less observable, or unobservable in the market, the determination of fair value requires more judgment. Accordingly, the degree of judgment exercised by the Company in determining fair value is greatest for instruments categorized within Level 3. A financial instrument’s level within the fair value hierarchy is based on the lowest level of any input that is significant to the fair value measurement. There have been no significant changes to the valuation methods utilized by the Company during the periods presented. There have been no transfers between Level 1, Level 2, and Level 3 in any periods presented. The carrying amounts of financial instruments consisting of cash and cash equivalents, investments, prepaid expenses and other current assets, accounts payable, accrued expenses and other current liabilities included in the Company’s financial statements, are reasonable estimates of fair value, primarily due to their short maturities. Marketable securities are classified as long-term investments if the Company has the ability and intent to hold them and such holding period is longer than one year. The Company classifies all of its investments as available-for-sale. Our available-for-sale, short-term and long-term investments, which consist of, commercial paper, corporate bonds, and government agency securities are considered to be Level 2 valuations. The fair value of Level 2 financial assets is determined using inputs that are observable in the market or can be derived principally from or corroborated by observable market data, such as pricing for similar securities, recently executed transactions, cash flow models with yield curves, and benchmark securities. In addition, Level 2 financial instruments are valued using comparisons to like-kind financial instruments and models that use readily observable market data as their basis.
Property and Equipment, net	Property and Equipment, net Property and equipment, net, is stated at cost, less accumulated depreciation. Maintenance and repairs that do not improve or extend the lives of the respective assets are expensed to operations as incurred, while costs of major additions and betterments are capitalized. Upon disposal, the related cost and accumulated depreciation is removed from the accounts and any resulting gain or loss is included in the results of operations. Depreciation is recorded using the straight-line method over the estimated useful lives of the respective assets, which are as follows: Computer equipment and software 3 - 7 years Lab equipment 3 - 7 years Furniture and fixtures 3 - 7 years Leasehold improvement lesser of remaining useful life or remaining lease term Construction in progress ("CIP") is not depreciated until the asset is placed in service.
Impairment of Long-Lived Assets	Impairment of Long-Lived Assets The Company evaluates long-lived assets for potential impairment when events or changes in circumstances indicate the carrying value of the assets may not be recoverable. An impairment loss would be recognized when estimated future cash flows expected to result from the use of the asset and its eventual disposition are less than the carrying amount of the asset. The Company has not recognized any impairment losses for the three months ended March 31, 2022 and 2021.
Leases	Leases The Company accounts for its lease agreements in accordance with FASB ASC Topic 842, Leases ("ASC 842"). Right-of-use lease assets represent our right to use an underlying asset during the lease term and the lease obligations represent our commitment to make lease payments arising from the lease. Right-of-use lease assets and obligations are recognized based on the present value of remaining lease payments over the lease term. As the Company’s lease agreements do not provide an implicit rate and as the Company does not have any external borrowings, we have used an estimated incremental borrowing rate based on the information available at lease commencement in determining the present value of lease payments. Operating lease expense is recognized on a straight-line basis over the lease term. Variable lease expense is recognized in the period in which the obligation for the payment is incurred. In addition, the Company also has made an accounting policy election to exclude leases with an initial term of twelve months or less from its balance sheet and to account for lease and non-lease components of its operating leases as a single component. For lease arrangements where it has been determined that the Company has control over an asset that is under construction and is thus considered the accounting owner of the asset during the construction period, the Company records a construction in progress asset and corresponding financial obligation on the condensed consolidated balance sheet. Once the construction is complete, an assessment is performed to determine whether the lease meets certain "sale-leaseback" criteria. If the sale-leaseback criteria are determined to be met, the Company will remove the asset and related financial obligation from the condensed consolidated balance sheet and treat the lease as either an operating or finance lease based on our assessment of the guidance. If, upon completion of construction, the project does not meet the "sale-leaseback" criteria, the lease will be treated as a financing obligation and the Company will depreciate the asset over its estimated useful life for financial reporting purposes once the asset has been placed into service.
Research and Development Expenses	Research and Development Expenses Research and development costs are charged to expense as incurred in performing research and development activities. These costs include employee compensation costs, facilities and overhead, preclinical and clinical activities, related clinical manufacturing costs, contract management services, regulatory and other related costs. The Company estimates contract research and clinical trials materials manufacturing expenses based on the services performed pursuant to contracts with research organizations and manufacturing organizations that manufacture materials used in the Company’s ongoing preclinical and clinical studies. Non-refundable advanced payments for goods or services to be received in the future for use in research and development activities are deferred and capitalized. The capitalized amounts are expensed as the related goods are delivered or the services are performed. In accruing service fees, the Company estimates the time period over which services will be performed and the level of effort to be expended in each period. These estimates are based on communications with the third party service providers and the Company’s estimates of accrued expenses using information available at each balance sheet date. If the actual timing of the performance of services or the level of effort varies from the estimate, the Company will adjust the accrual accordingly.
Stock-Based Compensation Expense	Stock-Based Compensation Expense The Company applies the fair value recognition provisions of Financial Accounting Standards Board Accounting Standards Codification, or ASC, Topic 718, Compensation—Stock Compensation ("ASC 718"), to account for stock-based compensation. Compensation costs related to stock options granted is based on the estimated fair value of the awards on the date of grant. ASC 718 requires all stock-based payments, including grants of stock options and restricted stock, to be recognized in the statements of operations based on their grant-date fair values. Compensation expense is recognized on a straight-line basis based on the grant-date fair value over the associated service period of the award, which is generally the vesting term. The Company estimates the fair value of its stock options using the Black-Scholes option pricing model, which requires the input of subjective assumptions, including: (i) the expected stock price volatility; (ii) the expected term of the award; (iii) the risk-free interest rate; and (iv) expected dividends. Once the Company's own sufficient historical volatility data was obtained, the Company eliminated the use of a representative peer group and uses only its own historical volatility data in its estimate of expected volatility. The Company estimates the expected term of its stock options using the “simplified” method, whereby the expected term equals the arithmetic mean of the vesting term and the original contractual term of the option. The risk-free interest rates are based on US Treasury securities with a maturity date commensurate with the expected term of the associated award. The
Comprehensive Loss	Comprehensive Loss Comprehensive loss is defined as the change in equity during a period from transactions from non-owner sources. Unrealized gains or losses on available-for-sale securities is a component of other comprehensive gains or losses and is presented net of taxes. We have not recorded any reclassifications from other comprehensive gains or losses to net loss during any period presented.
Recent Accounting Pronouncements	Recent Accounting Pronouncements ASU No. 2020-08, Codification Improvements to Subtopic 310-20, Receivables - Nonrefundable Fees and Other Costs In October 2020, the FASB issued ASU 2020-08, Codification Improvements to Subtopic 310-20, Receivables - Nonrefundable Fees and Other Costs ("ASU 2020-08") to provide further clarification and update the previously issued guidance in ASU 2017-08, Receivables - Nonrefundable Fees and Other Costs (Subtopic 310-20: Premium Amortization on Purchased Callable Debt Securities) ("ASU 2017-08"). ASU 2017-08 shortened the amortization period for certain callable debt securities purchased at a premium by requiring that the premium be amortized to the earliest call date. ASU 2020-08 requires that at each reporting period, to the extent that the amortized cost of an individual callable debt security exceeds the amount repayable by the issuer at the next call date, the excess premium shall be amortized to the next call date. The new standard was effective beginning January 1, 2021 and should be applied on a prospective basis as of the beginning of the period of adoption for existing or newly purchased callable debt securities. The adoption of ASU 2020-08 did not have a material impact on the Company's financial position or results of operations upon adoption.

Summary of Significant Accoun_3

Summary of Significant Accounting Policies (Tables)	3 Months Ended
	Mar. 31, 2022
Accounting Policies [Abstract]
Summary of Estimated Useful Lives of Assets	Depreciation is recorded using the straight-line method over the estimated useful lives of the respective assets, which are as follows: Computer equipment and software 3 - 7 years Lab equipment 3 - 7 years Furniture and fixtures 3 - 7 years Leasehold improvement lesser of remaining useful life or remaining lease term

Net Loss Per Share Attributab_2

Net Loss Per Share Attributable to Common Stockholders (Tables)	3 Months Ended
	Mar. 31, 2022
Earnings Per Share [Abstract]
Schedule of Net Loss Per Share Attributable to Common Stockholders	Three Months Ended 2022 2021 (In thousands, except shares and per share data) (Unaudited) Numerator: Net loss per common share $ (49,965) $ (15,812) Denominator: Weighted-average basic and diluted common shares 25,114,453 21,253,508 Basic and diluted net loss per $ (1.99) $ (0.74)

Fair Value Instruments (Tables)

Fair Value Instruments (Tables)	3 Months Ended
	Mar. 31, 2022
Fair Value Disclosures [Abstract]
Summary of Cash, Cash Equivalents and Available-for-Sale Securities	The following tables show the Company’s cash, cash equivalents and available-for-sale securities by significant investment category as of March 31, 2022 and December 31, 2021, respectively (in thousands): March 31, 2022 (unaudited) Amortized Cost Gross Gross Aggregate Fair Cash and Cash Short-term Marketable Securities (1) Long-term Marketable Securities (2) Level 1: Cash and cash equivalents $ 269,303 $ — $ — $ 269,303 $ 269,303 $ — $ — Subtotal 269,303 — — 269,303 269,303 — — Level 2: Commercial paper 39,476 — (37) 39,439 — 39,439 — Corporate bonds 106,741 2 (724) 106,019 — 81,961 24,058 U.S. government agency securities 53,650 — (440) 53,210 — 43,929 9,281 Subtotal 199,867 2 (1,201) 198,668 — 165,329 33,339 Total $ 469,170 $ 2 $ (1,201) $ 467,971 $ 269,303 $ 165,329 $ 33,339 December 31, 2021 Amortized Cost Gross Gross Aggregate Fair Cash and Cash Short-term Marketable Securities (1) Long-term Marketable Securities (2) Level 1: Cash and cash equivalents $ 341,246 $ — $ — $ 341,246 $ 341,246 $ — $ — Subtotal 341,246 — — 341,246 341,246 — — Level 2: Commercial paper 40,469 1 (4) 40,466 — 40,466 — Corporate bonds 83,300 10 (114) 83,196 — 35,768 47,428 U.S. government agency securities 37,621 — (62) 37,559 — 20,616 16,943 Subtotal 161,390 11 (180) 161,221 — 96,850 64,371 Total $ 502,636 $ 11 $ (180) $ 502,467 $ 341,246 $ 96,850 $ 64,371 (1) The Company’s short-term marketable securities mature in one year or less. (2) The Company's long-term marketable securities mature between one year and two years.

Balance Sheet Components (Table

Balance Sheet Components (Tables)	3 Months Ended
	Mar. 31, 2022
Balance Sheet Related Disclosures [Abstract]
Schedule of Property and Equipment, Net	Property and equipment, net consist of the following (in thousands): March 31, December 31, (Unaudited) Construction in progress $ 128,933 $ 104,340 Leasehold improvements 5,736 5,723 Furniture and fixtures 900 891 Computer equipment and software 96 85 Laboratory and manufacturing equipment 5,938 5,530 Total property and equipment 141,603 116,569 Accumulated depreciation and amortization (4,676) (4,214) Property and equipment, net $ 136,927 $ 112,355
Schedule of Accrued Expenses And Other Current Liabilities	Accrued expenses and other current liabilities consisted of the following (in thousands): March 31, December 31, (Unaudited) Accrued preclinical and clinical expenses $ 2,647 $ 1,602 Accrued professional fees 4,168 2,011 Accrued payroll and benefits 1,560 2,882 Accrued taxes 149 83 Accrued construction in progress 17,097 9,606 Accrued financing costs 54 26 Accrued litigation settlement 25,000 — Other current liabilities 142 87 Total $ 50,817 $ 16,297

Commitments and Contingencies (

Commitments and Contingencies (Tables)	3 Months Ended
	Mar. 31, 2022
Commitments and Contingencies Disclosure [Abstract]
Schedule of Future Minimum Operating Lease Payments	As of March 31, 2022, future minimum commitments under the Company’s operating leases were as follows (in thousands): Operating 2022 (remaining nine months) $ 1,115 2023 1,510 2024 1,539 2025 1,277 2026 1,277 Thereafter 12,063 Future minimum operating lease payments $ 18,781 Less: Interest 9,487 Present value of lease liability $ 9,294
Schedule of Supplemental Condensed Consolidated Balance Sheet Information Related to Leases	Supplemental condensed consolidated balance sheet information related to leases is as follows: (unaudited) March 31, 2022 December 31, 2021 Operating leases: Right-of-use assets $ 8,453 $ 7,228 Current portion of lease liability 1,411 1,041 Lease liability 7,883 6,983 Total lease liability $ 9,294 $ 8,024 Weighted average remaining lease term, in years 13.0 14.4 Weighted average discount rate 9.3 % 9.5 %

Stock-Based Compensation (Table

Stock-Based Compensation (Tables)	3 Months Ended
	Mar. 31, 2022
Share-based Payment Arrangement [Abstract]
Schedule of Company's Stock Option Activity	The following table summarizes the Company’s stock option activity: Stock Weighted- Weighted- Aggregate Intrinsic Value (In thousands) (1) Outstanding at December 31, 2021 2,043,179 $ 57.00 9.0 $ 31,331 Granted 1,179,500 $ 62.53 Exercised (1,475) $ 37.34 Cancelled or forfeited (68,342) $ 61.24 Expired — $ — Outstanding at March 31, 2022 3,152,862 $ 58.99 9.1 $ 30,364 Exercisable at March 31, 2022 439,954 $ 44.52 7.6 $ 10,929 (1) Aggregate intrinsic value represents the difference between the closing stock price of our common stock on March 31, 2022 and the exercise price of outstanding in-the-money options.
Summary of Stock Based Compensation Expense Related to Issuance of Stock Option Awards and Restricted Stock Awards	The Company has recorded aggregate stock-based compensation expense related to the issuance of stock option awards in the condensed consolidated statements of operations for the three months ended March 31, 2022 and 2021 as follows (in thousands): Three Months Ended March 31, 2022 2021 (unaudited) Research and development $ 1,368 $ 516 General and administrative 4,582 1,615 Total stock-based compensation $ 5,950 $ 2,131 The Company recorded stock-based compensation expense related to RSAs of $480 thousand and $182 thousand for the three months ended March 31, 2022 and 2021, respectively, within general and administrative expenses in the accompanying condensed consolidated statements of operations (in thousands): Three Months Ended March 31, 2022 2021 (unaudited) General and administrative $ 480 $ 182 Total stock-based compensation $ 480 $ 182
Fair Value of Stock Options, Valuation Assumptions	The fair value of options was estimated at the date of grant using the Black-Scholes valuation model with the following weighted-average assumptions for the three months ended March 31, 2022 and 2021: Three Months Ended March 31, 2022 2021 Expected stock price volatility 78 % 73 % Expected term of the award (years) 6.24 6.22 Risk-free interest rate 1.79 % 1.00 % Weighted average exercise price $ 62.53 $ 77.46 Forfeiture rate — % — %
Share-based Payment Arrangement, Restricted Stock and Restricted Stock Unit, Activity	Number of Shares Weighted Average Non-vested RSAs as of December 31, 2021 98,800 $ 78.89 Granted — $ — Vested (14,321) $ 78.89 Forfeited (10,379) $ 78.89 Non-vested RSAs as of March 31, 2022 74,100 $ 78.89

Organization - Additional Infor

Organization - Additional Information (Detail) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Accounting Policies [Abstract]
Accumulated deficit	$ 190,749	$ 140,784
Cash, cash equivalents and short-term investments	$ 434,600

Summary of Significant Accoun_4

Summary of Significant Accounting Policies - Additional Information (Detail)	3 Months Ended
	Mar. 31, 2022USD ($)segment	Mar. 31, 2021USD ($)
Significant Accounting Policies [Line Items]
Number of operating segment | segment	1
Equipment
Significant Accounting Policies [Line Items]
Recognized impairment losses for long lived assets | $	$ 0	$ 0

Summary of Significant Accoun_5

Summary of Significant Accounting Policies - Summary of Estimated Useful Lives of Assets (Detail)	3 Months Ended
	Mar. 31, 2022
Computer equipment and software | Minimum
Property, Plant and Equipment [Line Items]
Estimated useful lives of assets	3 years
Computer equipment and software | Maximum
Property, Plant and Equipment [Line Items]
Estimated useful lives of assets	7 years
Laboratory and manufacturing equipment | Minimum
Property, Plant and Equipment [Line Items]
Estimated useful lives of assets	3 years
Laboratory and manufacturing equipment | Maximum
Property, Plant and Equipment [Line Items]
Estimated useful lives of assets	7 years
Furniture and fixtures | Minimum
Property, Plant and Equipment [Line Items]
Estimated useful lives of assets	3 years
Furniture and fixtures | Maximum
Property, Plant and Equipment [Line Items]
Estimated useful lives of assets	7 years

Net Loss Per Share Attributab_3

Net Loss Per Share Attributable to Common Stockholders - Additional Information (Detail) - shares	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Earnings Per Share [Abstract]
Common share equivalents outstanding, excluded from the calculation of diluted net loss per common share	3,226,962	1,423,540

Net Loss Per Share Attributab_4

Net Loss Per Share Attributable to Common Stockholders - Schedule of Basic and Diluted Net Loss Per Share and Per Unit (Detail) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Numerator:
Net loss per common share	$ (49,965)	$ (15,812)
Denominator:
Weighted-average common shares outstanding: basic	25,114,453	21,253,508
Weighted-average common shares outstanding: diluted	25,114,453	21,253,508
Net loss per common share: basic (in dollars per share)	$ (1.99)	$ (0.74)
Net loss per common share: diluted (in dollars per share)	$ (1.99)	$ (0.74)

Fair Value Instruments - Summar

Fair Value Instruments - Summary of Cash, Cash Equivalents and Available-for-Sale Securities (Detail) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and cash equivalents	$ 269,303	$ 341,246
Gross Unrealized Gains	2	11
Gross Unrealized Losses	(1,201)	(180)
Amortized Cost	469,170	502,636
Aggregate fair value, total	467,971	502,467
Cash and Cash Equivalents
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Aggregate fair value, total	269,303	341,246
Short-term Marketable Securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Aggregate fair value, total	165,329	96,850
Long-term Marketable Securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Aggregate fair value, total	33,339	64,371
Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and cash equivalents	269,303	341,246
Aggregate Fair Value	269,303	341,246
Level 1 | Cash and Cash Equivalents
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and cash equivalents	269,303	341,246
Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Amortized Cost	199,867	161,390
Gross Unrealized Gains	2	11
Gross Unrealized Losses	(1,201)	(180)
Aggregate Fair Value	198,668	161,221
Level 2 | Short-term Marketable Securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Aggregate Fair Value	$ 165,329	96,850
Debt securities, available-for-sale, term	1 year
Level 2 | Long-term Marketable Securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Aggregate Fair Value	$ 33,339	64,371
Level 2 | Long-term Marketable Securities | Minimum
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities, available-for-sale, term	1 year
Level 2 | Long-term Marketable Securities | Maximum
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities, available-for-sale, term	2 years
Cash and cash equivalents | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and cash equivalents	$ 269,303	341,246
Aggregate Fair Value	269,303	341,246
Cash and cash equivalents | Level 1 | Cash and Cash Equivalents
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and cash equivalents	269,303	341,246
Commercial paper
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Amortized Cost	39,476	40,469
Gross Unrealized Gains	0	1
Gross Unrealized Losses	(37)	(4)
Aggregate Fair Value	39,439	40,466
Commercial paper | Short-term Marketable Securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Aggregate Fair Value	39,439	40,466
Commercial paper | Long-term Marketable Securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Aggregate Fair Value	0	0
Corporate bonds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Amortized Cost	106,741	83,300
Gross Unrealized Gains	2	10
Gross Unrealized Losses	(724)	(114)
Aggregate Fair Value	106,019	83,196
Corporate bonds | Short-term Marketable Securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Aggregate Fair Value	81,961	35,768
Corporate bonds | Long-term Marketable Securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Aggregate Fair Value	24,058	47,428
U.S. government agency securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Amortized Cost	53,650	37,621
Gross Unrealized Gains	0	0
Gross Unrealized Losses	(440)	(62)
Aggregate Fair Value	53,210	37,559
U.S. government agency securities | Short-term Marketable Securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Aggregate Fair Value	43,929	20,616
U.S. government agency securities | Long-term Marketable Securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Aggregate Fair Value	$ 9,281	$ 16,943

Balance Sheet Components - Sche

Balance Sheet Components - Schedule of Property and Equipment, Net (Detail) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Property, Plant and Equipment [Line Items]
Total property and equipment	$ 141,603	$ 116,569
Accumulated depreciation and amortization	(4,676)	(4,214)
Property and equipment, net	136,927	112,355
Construction in progress
Property, Plant and Equipment [Line Items]
Total property and equipment	128,933	104,340
Leasehold improvements
Property, Plant and Equipment [Line Items]
Total property and equipment	5,736	5,723
Furniture and fixtures
Property, Plant and Equipment [Line Items]
Total property and equipment	900	891
Computer equipment and software
Property, Plant and Equipment [Line Items]
Total property and equipment	96	85
Laboratory and manufacturing equipment
Property, Plant and Equipment [Line Items]
Total property and equipment	$ 5,938	$ 5,530

Balance Sheet Components - Addi

Balance Sheet Components - Additional Information (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Balance Sheet Related Disclosures [Abstract]
Depreciation expense	$ 462	$ 438

Balance Sheet Components - Sc_2

Balance Sheet Components - Schedule of Accrued Expenses And Other Current Liabilities (Detail) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Balance Sheet Related Disclosures [Abstract]
Accrued preclinical and clinical expenses	$ 2,647	$ 1,602
Accrued professional fees	4,168	2,011
Accrued payroll and benefits	1,560	2,882
Accrued taxes	149	83
Accrued construction in progress	17,097	9,606
Accrued financing costs	54	26
Accrued litigation settlement	25,000	0
Other current liabilities	142	87
Total	$ 50,817	$ 16,297

Commitments and Contingencies -

Commitments and Contingencies - Additional Information (Detail) ft² in Thousands, $ in Thousands	Mar. 12, 2022USD ($)	Oct. 15, 2020USD ($)	Mar. 31, 2022USD ($)ft²milestone	Mar. 31, 2021USD ($)	Dec. 31, 2021USD ($)	Dec. 15, 2021	Sep. 13, 2021USD ($)	Oct. 05, 2020USD ($)	Jan. 21, 2020USD ($)
Operating Leased Assets [Line Items]
Cash contribution								$ 2,400	$ 2,400
Purchase price of potential purchase		$ 9,400
Finance lease, liability								10,000
Construction in progress, gross								$ 10,000
Escrow deposit		$ 1,500
Lessor, operating lease, liability, annual lease payments			$ 82
Cumulative escalation clause			0.10
Cumulative escalation clause, term			5 years
2022			$ 1,510
2023			1,539
2024			1,277
2025			1,277
Operating lease costs			409	$ 218
Variable lease costs			49	37
Loss contingency, guaranteed maximum price to be paid							$ 82,300
Litigation settlement			25,000	0
Proceeds from insurance settlement, operating activities			768
Gain related to litigation settlement			301
Accrued litigation settlement			25,000		$ 0
PeriphaGen
Operating Leased Assets [Line Items]
Litigation settlement	$ 25,000
Litigation settlement, amount awarded to other party			$ 12,500
Number of milestones | milestone			3
Litigation settlement, total consideration	75,000
Milestone One | PeriphaGen
Operating Leased Assets [Line Items]
Litigation settlement, amount awarded to other party			$ 12,500
Litigation settlement, milestone payments, sales threshold	100,000
Milestone Two | PeriphaGen
Operating Leased Assets [Line Items]
Litigation settlement, amount awarded to other party			12,500
Litigation settlement, milestone payments, sales threshold	200,000
Milestone Three | PeriphaGen
Operating Leased Assets [Line Items]
Litigation settlement, amount awarded to other party			12,500
Litigation settlement, milestone payments, sales threshold	$ 300,000
Clinical Supply Agreements
Operating Leased Assets [Line Items]
Estimated remaining commitment			3,100
Project management service fee			1,800	1,800
Other Contractual Obligations
Operating Leased Assets [Line Items]
Estimated remaining commitment			4,300
Project management service fee			3,100	$ 1,300
ASTRA Facility
Operating Leased Assets [Line Items]
Contractual obligation			$ 20,200
Cost of work, percentage			0.0175
2016 Lease Agreement
Operating Leased Assets [Line Items]
Additional area of real estate property leased | ft²			47
Boston Lease
Operating Leased Assets [Line Items]
Operating lease, term of contract						3 years

Commitments and Contingencies_2

Commitments and Contingencies - Schedule of Future Minimum Operating Lease Payments (Detail) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Commitments and Contingencies Disclosure [Abstract]
2022 (remaining nine months)	$ 1,115
2023	1,510
2024	1,539
2025	1,277
2026	1,277
Thereafter	12,063
Future minimum operating lease payments	18,781
Less: Interest	9,487
Present value of lease liability	$ 9,294	$ 8,024

Commitments and Contingencies_3

Commitments and Contingencies - Schedule of Supplemental Condensed Consolidated Balance Sheet Information Related to Leases (Detail) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Lessee, Operating Lease, Liability, Payment, Due [Abstract]
Right-of-use assets	$ 8,453	$ 7,228
Current portion of lease liability	1,411	1,041
Lease liability	7,883	6,983
Total lease liability	$ 9,294	$ 8,024
Weighted average remaining lease term, in years	13 years	14 years 4 months 24 days
Weighted average discount rate	9.30%	9.50%

Capitalization - Additional Inf

Capitalization - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Thousands	Dec. 03, 2021	Feb. 01, 2021	Mar. 31, 2021	Dec. 31, 2020
Schedule of Capitalization, Equity [Line Items]
Offering expenses	$ 227	$ 198
Public Offering
Schedule of Capitalization, Equity [Line Items]
Issuance of common stock, net, (in shares)	2,866,667	2,211,538
Shares issued, price per share (in dollars per share)	$ 75	$ 65
Proceeds from initial offering of shares	$ 201,900	$ 134,900
Underwriting discounts and commissions	$ 12,900	$ 8,600
Over-Allotment Option
Schedule of Capitalization, Equity [Line Items]
Issuance of common stock, net, (in shares)	200,000	288,461
ATM Program
Schedule of Capitalization, Equity [Line Items]
Proceeds from initial offering of shares		$ 16,900
Underwriting discounts and commissions		$ 524
Sale of stock, number of shares issued in transaction			262,500
Sale of stock, price per share			$ 66.50
Sale of stock, remaining available issuance amount			$ 132,500
Stock Sale Agreement | Placement Shares
Schedule of Capitalization, Equity [Line Items]
Offering expenses				$ 172
Sale of stock, aggregate offering price				$ 150,000

Stock-Based Compensation - Addi

Stock-Based Compensation - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021	Dec. 31, 2021
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock option expiration period	10 years
Stock options granted (in shares)	1,179,500
Intrinsic value of options exercised	$ 36	$ 808
Share-based payment arrangement, amount capitalized	$ 141	$ 37
Director
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock options granted (in shares)	1,179,500	502,450
Stock Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares remaining available for grant	1,028,815
Share-based Payment Arrangement, Option
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock option vesting period	4 years
Weighted-average grant-date fair value per share of options granted (in dollars per share)	$ 43.09	$ 50.04
Stock-based compensation expense	$ 5,950	$ 2,131
Share-based Payment Arrangement, Option | Director
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized stock-based compensation expense	$ 101,100
Estimated weighted average period	3 years 4 months 24 days
Non-Employee Stock Option | Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock option vesting period	1 year
Non-Employee Stock Option | Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock option vesting period	4 years
Restricted Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted stock award granted (in shares)	0	98,800
Restricted stock award outstanding (in shares)	74,100		98,800
Unrecognized stock-based compensation expense	$ 5,700
Estimated weighted average period	2 years 10 months 24 days
Stock-based compensation expense	$ 480	$ 182
Restricted Stock | Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock option vesting period	4 years
Incentive Stock Options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares remaining available for grant	26,546

Stock-Based Compensation - Sche

Stock-Based Compensation - Schedule of Company's Stock Option Activity (Detail) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2022	Dec. 31, 2021
Stock Options Outstanding
Beginning balance (in shares)	2,043,179
Granted (in shares)	1,179,500
Exercised (in shares)	(1,475)
Cancelled or forfeited (in shares)	(68,342)
Expired (in shares)	0
Ending balance (in shares)	3,152,862	2,043,179
Exercisable end of period (in shares)	439,954
Weighted- average Exercise Price
Beginning balance (in dollars per share)	$ 57
Granted (in dollars per share)	62.53
Exercised (in dollars per share)	37.34
Cancelled or forfeited (in dollars per share)	61.24
Exercised (in dollars per share)	0
Ending balance (in dollars per share)	58.99	$ 57
Exercisable end of period (in dollars per share)	$ 44.52
Weighted- average Remaining Contractual Life (Years)
Weighted-average remaining contractual life (Years)	9 years 1 month 6 days	9 years
Weighted-average remaining contractual life (Years), exercisable	7 years 7 months 6 days
Aggregate Intrinsic Value
Aggregate intrinsic value, outstanding	$ 30,364	$ 31,331
Exercisable at March 31, 2022	$ 10,929

Stock-Based Compensation - Summ

Stock-Based Compensation - Summary of Stock Based Compensation Expense Related to Issuance of Stock Option Awards and Restricted Stock Awards (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Share-based Payment Arrangement, Option
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Total stock-based compensation	$ 5,950	$ 2,131
Restricted Stock
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Total stock-based compensation	480	182
Research and development | Share-based Payment Arrangement, Option
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Total stock-based compensation	1,368	516
General and administrative | Share-based Payment Arrangement, Option
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Total stock-based compensation	4,582	1,615
General and administrative | Restricted Stock
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Total stock-based compensation	$ 480	$ 182

Stock-Based Compensation - Fair

Stock-Based Compensation - Fair Value of Stock Options, Valuation Assumptions (Detail) - $ / shares	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected term of the award (years)	6 years 2 months 26 days	6 years 2 months 19 days
Share-based Payment Arrangement, Option
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected stock price volatility	78.00%	73.00%
Risk-free interest rate	1.79%	1.00%
Weighted average exercise price (in dollars per share)	$ 62.53	$ 77.46
Forfeiture rate	0.00%	0.00%

Stock-Based Compensation - Sc_2

Stock-Based Compensation - Schedule of Company's Restricted Stock Activity (Details) - Restricted Stock - $ / shares	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Number of Shares
Beginning balance (in shares)	98,800
Granted (in shares)	0	98,800
Vested (in shares)	(14,321)
Forfeited (in shares)	(10,379)
Ending balance (in shares)	74,100
Weighted Average Grant Date Fair Value
Beginning balance (in dollars per share)	$ 78.89
Granted (in dollars per share)	0
Vested (in dollars per share)	78.89
Forfeited (in dollars per share)	78.89
Ending balance (in dollars per share)	$ 78.89

Subsequent Events (Details)

Subsequent Events (Details) - USD ($) $ / shares in Units, $ in Thousands	Apr. 29, 2022	Apr. 05, 2022	Mar. 12, 2022	Mar. 31, 2022	Mar. 31, 2021
Subsequent Event [Line Items]
Litigation settlement				$ 25,000	$ 0
Public Offering | Subsequent Event
Subsequent Event [Line Items]
Sale of stock, number of shares issued in transaction		434,782
Sale of stock, price per share		$ 69
Sale of stock, consideration received on transaction		$ 29,100
PeriphaGen
Subsequent Event [Line Items]
Litigation settlement			$ 25,000
PeriphaGen | Subsequent Event
Subsequent Event [Line Items]
Litigation settlement	$ 25,000