0000950170-23-010314 | 10-K | XBRL Viewer

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Document and Entity Information - USD ($) $ in Millions	12 Months Ended
Document and Entity Information - USD ($) $ in Millions	Dec. 31, 2022	Feb. 28, 2023	Jun. 30, 2022
Cover [Abstract]
Document Type	10-K
Amendment Flag	false
Document Period End Date	Dec. 31, 2022
Document Fiscal Period Focus	FY
Document Fiscal Year Focus	2022
Trading Symbol	KOD
Entity Registrant Name	KODIAK SCIENCES INC.
Entity Central Index Key	0001468748
Current Fiscal Year End Date	--12-31
Entity Filer Category	Non-accelerated Filer
Entity File Number	001-38682
Entity Tax Identification Number	27-0476525
Entity Address, Address Line One	1200 Page Mill Road
Entity Address, City or Town	Palo Alto
Entity Address, State or Province	CA
Entity Address, Postal Zip Code	94304
City Area Code	650
Local Phone Number	281-0850
Entity Incorporation, State or Country Code	DE
Entity Interactive Data Current	Yes
Document Annual Report	true
Document Transition Report	false
Title of 12(b) Security	Common stock, par value $0.0001
Security Exchange Name	NASDAQ
Entity Well-known Seasoned Issuer	No
Entity Current Reporting Status	Yes
Entity Voluntary Filers	No
Entity Small Business	true
Entity Emerging Growth Company	false
Entity Shell Company	false
ICFR Auditor Attestation Flag	false
Entity Common Stock, Shares Outstanding		52,336,448
Entity Public Float			$ 242.6
Auditor Firm ID	238
Auditor Name	PricewaterhouseCoopers LLP
Auditor Location	San Jose, California
Documents Incorporated by Reference	DOCUMENTS INCORPORATED BY REFERENCE Portions of the registrant’s definitive Proxy Statement relating to the 2023 Annual Meeting of Stockholders are incorporated herein by reference in Part III of this Annual Report on Form 10-K to the extent stated herein. The proxy statement will be filed with the Securities and Exchange Commission within 120 days of the registrant’s fiscal year ended December 31, 2022.

Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Current assets:
Cash and cash equivalents	$ 190,433	$ 731,510
Marketable securities	288,500	0
Prepaid expenses and other current assets	7,072	3,301
Total current assets	486,005	734,811
Restricted cash	6,324	6,324
Property and equipment, net	56,384	41,330
Operating lease right-of-use asset	59,369	66,744
Other assets	58,546	55,011
Total assets	666,628	904,220
Current liabilities:
Accounts payable	9,130	12,431
Accrued and other current liabilities	33,440	48,319
Operating lease liability	9,926	3,933
Total current liabilities	52,496	64,683
Operating lease liability, net of current portion	77,807	76,063
Liability related to sale of future royalties	99,996	99,943
Other liabilities	162	211
Total liabilities	230,461	240,900
Commitments and contingencies (Note 8)
Stockholders’ equity:
Preferred stock, $0.0001 par value, 10,000,000 shares authorized; 0 shares issued and outstanding at December 31, 2022 and December 31, 2021, respectively	0	0
Common stock, $0.0001 par value, 490,000,000 shares authorized at December 31, 2022 and December 31, 2021; 52,333,850 and 51,826,257 shares issued and outstanding at December 31, 2022 and December 31, 2021, respectively	5	5
Additional paid-in capital	1,329,509	1,221,532
Accumulated other comprehensive income (loss)	(1,307)	0
Accumulated deficit	(892,040)	(558,217)
Total stockholders’ equity	436,167	663,320
Total liabilities and stockholders’ equity	$ 666,628	$ 904,220

Consolidated Balance Sheets (Parenthetical) - $ / shares	Dec. 31, 2022	Dec. 31, 2021
Statement of Financial Position [Abstract]
Preferred stock, par value	$ 0.0001	$ 0.0001
Preferred stock, shares authorized	10,000,000	10,000,000
Preferred Stock, shares issued	0	0
Preferred Stock, shares outstanding	0	0
Common stock, par value	$ 0.0001	$ 0.0001
Common stock, shares authorized	490,000,000	490,000,000
Common stock, shares issued	52,333,850	51,826,257
Common stock, shares outstanding	52,333,850	51,826,257

Consolidated Statements of Operations and Comprehensive Loss - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Operating expenses
Research and development	$ 267,591	$ 217,340	$ 107,389
General and administrative	73,788	49,711	28,618
Total operating expenses	341,379	267,051	136,007
Loss from operations	(341,379)	(267,051)	(136,007)
Interest income	7,071	298	2,966
Interest expense	(18)	(47)	(25)
Other income (expense), net	503	(190)	(30)
Net loss	$ (333,823)	$ (266,990)	$ (133,096)
Net loss per share common share, basic	$ (6.39)	$ (5.16)	$ (2.91)
Net loss per share common share, diluted	$ (6.39)	$ (5.16)	$ (2.91)
Weighted-average shares of common stock outstanding used in computing net loss per common share, basic	52,249,620	51,788,918	45,741,845
Weighted-average shares of common stock outstanding used in computing net loss per common share, diluted	52,249,620	51,788,918	45,741,845
Other comprehensive income (loss)
Change in unrealized gains (losses) related to available-for-sale debt securities, net of tax	$ (1,307)	$ (53)	$ 43
Total other comprehensive income (loss)	(1,307)	(53)	43
Comprehensive loss	$ (335,130)	$ (267,043)	$ (133,053)

Consolidated Statements of Stockholders' Equity - USD ($) $ in Thousands	Total	Common Stock	Additional Paid-In Capital	Accumulated Other Comprehensive Income	Accumulated Deficit
Beginning Balance at Dec. 31, 2019	$ 345,359	$ 5	$ 503,475	$ 10	$ (158,131)
Beginning balance, shares at Dec. 31, 2019		44,413,404
Issuance of common stock upon exercise of stock options	6,248		6,248
Issuance of common stock upon exercise of stock options, shares		704,675
Issuance of common stock in connection with follow-on offering, net of offering costs	612,016		612,016
Issuance of common stock in connection with follow-on offering, net of offering costs, shares		5,972,222
Issuance of common stock upon vesting of restricted stock units, net of taxes withheld	(487)		(487)
Issuance of common stock upon vesting of restricted stock units, net of taxes withheld, shares		22,001
Stock-based compensation expense	30,668		30,668
Other comprehensive income	43			43
Net loss	(133,096)				(133,096)
Ending Balance at Dec. 31, 2020	860,751	$ 5	1,151,920	53	(291,227)
Ending balance, shares at Dec. 31, 2020		51,112,302
Issuance of common stock upon exercise of stock options	7,743		7,743
Issuance of common stock upon exercise of stock options, shares		463,796
Issuance of common stock pursuant to employee stock purchase plans	484		484
Issuance of common stock upon vesting of restricted stock units, net of taxes withheld, shares		93,218
Issuance of common stock pursuant to employee stock purchase plans, shares		6,958
Issuance of common stock upon exercise of common stock warrants, shares		149,983
Stock-based compensation expense	61,385		61,385
Other comprehensive income	(53)			(53)
Net loss	(266,990)				(266,990)
Ending Balance at Dec. 31, 2021	663,320	$ 5	1,221,532	0	(558,217)
Ending balance, shares at Dec. 31, 2021		51,826,257
Issuance of common stock upon exercise of stock options	1,770		1,770
Issuance of common stock upon exercise of stock options, shares		126,999
Issuance of common stock pursuant to employee stock purchase plans	174		174
Issuance of common stock upon vesting of restricted stock units, net of taxes withheld, shares		103,032
Issuance of common stock pursuant to employee stock purchase plans, shares		27,863
Issuance of common stock upon exercise of common stock warrants, shares		249,699
Stock-based compensation expense	106,033		106,033
Other comprehensive income	(1,307)			(1,307)
Net loss	(333,823)				(333,823)
Ending Balance at Dec. 31, 2022	$ 436,167	$ 5	$ 1,329,509	$ (1,307)	$ (892,040)
Ending balance, shares at Dec. 31, 2022		52,333,850

Consolidated Statements of Stockholders' Equity (Parenthetical) $ in Thousands	12 Months Ended
	Dec. 31, 2020 USD ($)
Statement of Stockholders' Equity [Abstract]
Offering costs with respect to issuance of common stock in connection with initial public offering/follow-on offering	$ 32,984

Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Cash flows from operating activities
Net loss	$ (333,823)	$ (266,990)	$ (133,096)
Adjustments to reconcile net loss to net cash provided by (used in) operating activities:
Depreciation	3,796	1,003	477
Stock-based compensation	106,033	61,385	30,668
Loss on disposal of long-lived assets		(120)
Net amortization (accretion) of premium (discount) on marketable securities	(1,068)	25	(51)
Settlement of derivative contracts	(616)	0	0
Amortization of operating lease right-of-use asset	7,205	7,708	3,731
Amortization of issuance costs	53	53	49
Changes in assets and liabilities:
Prepaid expenses and other current assets	(2,744)	(270)	(218)
Other assets	7,384	1,465	(1,814)
Accounts payable	1,660	(2,094)	5,224
Accrued and other current liabilities	(2,246)	13,511	11,748
Operating lease liability	7,907	1,814	(146)
Net cash provided by (used in) operating activities	(206,459)	(182,270)	(83,428)
Cash flows from investing activities
Purchase of property and equipment	(37,021)	(17,032)	(3,814)
Deposits on property and equipment	(10,342)	(46,266)	(3,184)
Purchase of marketable securities	(427,766)	0	(86,317)
Maturities of marketable securities	138,000	24,500	198,149
Proceeds from derivative activity	616	0	0
Net cash provided by (used in) investing activities	(336,513)	(38,798)	104,834
Cash flows from financing activities
Proceeds from issuance of common stock in connection with offering, net of offering costs	0	0	612,016
Proceeds from issuance of common stock upon options exercise	1,770	7,743	6,248
Payments for restricted stock units, net of taxes withheld	0	0	(487)
Proceeds from issuance of common stock pursuant to employee stock purchase plan	174	484	0
Proceeds from sale of future royalties, net of issuance costs	0	0	99,643
Principal payments of tenant improvement allowance payable	(49)	(45)	(38)
Principal payments of finance lease	0	0	(5)
Net cash provided by (used in) financing activities	1,895	8,182	717,377
Net increase (decrease) in cash, cash equivalents and restricted cash	(541,077)	(212,886)	738,783
Cash, cash equivalents and restricted cash, at beginning of period	737,834	950,720	211,937
Cash, cash equivalents and restricted cash, at end of period	196,757	737,834	950,720
Reconciliation of cash, cash equivalents and restricted cash to consolidated balance sheets
Cash and cash equivalents	190,433	731,510	944,396
Restricted cash	6,324	6,324	6,324
Cash, cash equivalents and restricted cash, at end of period	196,757	737,834	950,720
Supplemental cash flow information:
Cash paid for interest	18	22	25
Supplemental disclosures of non-cash investing and financing information:
Operating lease right-of-use asset obtained in exchange for operating lease liability	(170)	773	75,614
Purchase of property and equipment under accounts payable and accruals	2,917	21,088	803
Reclassification of deposits to property and equipment	5,363	2,370	0
Unpaid offering costs	$ 0	$ 0	$ 238

The Company

12 Months Ended

Dec. 31, 2022

Organization, Consolidation and Presentation of Financial Statements [Abstract]

The Company

1. The Company

Kodiak Sciences Inc. (the “Company”) is a clinical stage biopharmaceutical company committed to researching, developing and commercializing transformative therapeutics to treat high prevalence retinal diseases. The Company devotes substantially all of its resources to the research and development of its product platforms and product candidates including activities to conduct clinical studies of its product candidates, manufacture product candidates and provide general and administrative support for these operations.

Liquidity

As of December 31, 2022, the Company had cash, cash equivalents and marketable securities of $478.9 million. Although the Company has incurred significant operating losses since inception and expects to continue to incur operating losses and negative operating cash flows for the foreseeable future, the Company believes that the cash, cash equivalents and marketable securities will be sufficient to meet the anticipated operating and capital expenditure requirements for the 12 months following the date of this Annual Report on Form 10-K.

Summary of Significant Accounting Policies

12 Months Ended

Dec. 31, 2022

Accounting Policies [Abstract]

Summary of Significant Accounting Policies

2. Summary of Significant Accounting Policies

Basis of Presentation

The accompanying consolidated financial statements have been prepared in accordance with accounting principles generally accepted in the United States of America (“US GAAP”).

Reclassification

Certain prior period amounts in the consolidated financial statements have been reclassified to conform to the current period presentation.

Principles of Consolidation

The consolidated financial statements include the Company’s accounts and the accounts of Kodiak Sciences Financing Corporation and Kodiak Sciences China, the Company’s direct wholly owned subsidiaries, incorporated in the United States and Cayman Islands, respectively, and Kodiak Sciences GmbH and Kodiak Sciences Valais GmbH, the Company’s indirect wholly owned subsidiaries, both incorporated in Switzerland. All intercompany accounts and transactions have been eliminated. The functional and reporting currency of the Company and its subsidiaries is the U.S. dollar. The aggregate foreign currency transaction gain (loss) included in determining net loss was $0.3 million, $(0.3) million, and $(0.3) million for the years ended December 31, 2022, 2021 and 2020, respectively.

Segments

The Company operates and manages its business as one reportable and operating segment, which is the business of research and development of drugs for retinal diseases. The chief operating decision maker reviews financial information on an aggregate basis for purposes of allocating resources and evaluating financial performance.

Use of Estimates

The preparation of consolidated financial statements in conformity with US GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities, disclosure of contingent assets and liabilities as of the date of the consolidated financial statements and expenses during the reporting period. Such estimates include, but are not limited to, accrued research and development and stock-based compensation. Actual results could differ from those estimates.

Risk and Uncertainties

Global economic and business activities continue to face widespread macroeconomic uncertainties, including health epidemics, labor shortages, bank failures, inflation and monetary supply shifts, recession risks and potential disruptions from the Russia-Ukraine conflict. The Company continues to actively monitor the impact of these macroeconomic factors on its financial condition, liquidity, operations, and workforce. The extent of the impact of these factors on the Company’s operational and financial performance, including its ability to execute its business strategies and initiatives in the expected timeframe, will depend on future developments, which are uncertain and cannot be predicted; however, any continued or renewed disruption resulting from these factors could negatively impact the Company’s business.

The Company’s future results of operations involve a number of risks and uncertainties common to clinical stage companies in the biotechnology industry. The Company’s product candidates are in development and the Company operates in an environment of rapid change in technology and substantial competition from other pharmaceutical and biotechnology companies. Factors that could affect the Company’s future operating results and cause actual results to vary materially from expectations include, but are not limited to, uncertainty of results of clinical trials and reaching milestones, uncertainty of regulatory approval of the Company’s potential drug candidates, uncertainty of market acceptance of any of the Company’s product candidates that receive regulatory approval, competition from new technological innovations, substitute products and larger companies, securing and protecting proprietary technology, strategic relationships and dependence on key individuals, contract manufacturer and research organizations, and other suppliers.

Products developed by the Company require approvals from the U.S. Food and Drug Administration (“FDA”) or other international regulatory agencies prior to commercial sales. There can be no assurance that any of the Company’s product candidates will receive the necessary approvals. If the Company is denied approval, approval is delayed or the Company is unable to maintain approvals, it could have a materially adverse impact on the Company. Even if the Company’s product development efforts are successful, it is uncertain when, if ever, the Company will generate significant revenue from product sales.

The Company expects to incur substantial operating losses for the next several years and will need to obtain additional financing in order to complete clinical trials, launch and commercialize any product candidates for which it receives regulatory approval. There can be no assurance that such financing will be available or will be on terms acceptable by the Company.

Concentration of Credit Risk

Financial instruments that potentially subject the Company to a concentration of credit risk consist of cash, cash equivalents and marketable securities. As of December 31, 2022 and 2021, cash, cash equivalents and marketable securities were invested primarily in money market funds and U.S. treasury securities through highly rated financial institutions. Investments are restricted, in accordance with the Company’s investment policy, to a concentration limit per issuer or sector.

Cash and Cash Equivalents

The Company considers all highly liquid investments with stated maturities of three months or less at the date of purchase to be cash equivalents.

Marketable Securities

The Company may invest excess cash balances in marketable securities. The investments in marketable securities are classified as either held-to-maturity or available-for-sale based on facts and circumstances present at the time of purchase. Marketable securities with a remaining maturity date greater than one year are classified as non-current. The Company’s marketable securities can consist of U.S. treasury securities, commercial paper, and corporate bonds. Marketable debt securities that are available for sale, are carried at fair value with the unrealized gains and losses included in other comprehensive income (loss) as a component of stockholders’ equity until realized. Any premium or discount arising at purchase of marketable debt securities is amortized and/or accreted to interest income or expense over the life of the instrument. Realized gains and losses are determined using the specific identification method and are included in other income (expense), net.

If any adjustment to fair value reflects a decline in value of the investment, the Company considers all available evidence to evaluate the extent to which the decline is “other-than-temporary” and, if so, marks the investment to market through a charge to the consolidated statement of operations and comprehensive loss.

Restricted Cash

As of December 31, 2022, and 2021, the Company had $6.3 million and $6.3 million, respectively, of long-term restricted cash deposited with financial institutions. The entire amount is held in separate bank accounts to support letter of credit agreements related to the Company’s U.S. corporate offices.

Derivatives and Hedging

Derivative instruments that do not qualify for hedge accounting are recognized on the consolidated balance sheet at fair value, with changes in the fair value recognized on the consolidated statement of operations and comprehensive loss as a component of other income (expense), net. The cash flows associated with these derivatives are reflected as cash flows from investing activities in the consolidated statement of cash flows.

Fair Value of Financial Instruments

Accounting Standards Codification (“ASC”) 820, Fair Value Measurement, establishes a fair value hierarchy for instruments measured at fair value that distinguishes between assumptions based on market data (observable inputs) and the Company's own assumptions (unobservable inputs). Observable inputs are inputs that market participants would use in pricing the asset or liability based on market data obtained from sources independent of the Company. Unobservable inputs are inputs that reflect the Company's assumptions about the inputs that market participants would use in pricing the asset or liability and are developed based on the best information available in the circumstances.

Fair value is an exit price, representing the amount that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants. As a basis for considering market participant assumptions in fair value measurements, ASC 820 establishes a three-tier fair value hierarchy that distinguishes between the following:

Level 1—Observable inputs, such as quoted prices in active markets for identical assets or liabilities at the measurement date.

Level 2—Observable inputs other than Level 1 prices such as quoted prices for similar assets or liabilities, quoted prices in markets that are not active, or other inputs that are observable or can be corroborated by observable market data for substantially the full term of the assets or liabilities.

Level 3—Unobservable inputs which reflect management’s best estimate of what market participants would use in pricing the asset or liability at the measurement date. Consideration is given to the risk inherent in the valuation technique and inputs to the model.

To the extent that the 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 in 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.

The carrying amounts of the Company’s financial instruments consisting of cash and cash equivalents, prepaid expenses and other current assets, accounts payable and accrued liabilities and other current liabilities, approximate fair value due to their relatively short maturities.

Leases

The Company determines if an arrangement is, or contains, a lease at inception and then classifies the lease as operating or financing based on the underlying terms and conditions of the contract. Leases with terms greater than one year are initially recognized on the consolidated balance sheet as right-of-use assets and lease liabilities based on the present value of lease payments over the expected lease term. The interest rate implicit in lease contracts is typically not readily determinable. As such, the Company utilizes the incremental borrowing rate, which is the rate incurred to borrow, on a collateralized basis, an amount equal to the lease payments over a similar term and in a similar economic environment of the applicable country or region. Variable lease payments are excluded from the right of use assets and operating lease liabilities and are recognized in the period in which the obligation for those payments is incurred.

Property and Equipment, Net

Property and equipment are stated at cost, net of accumulated depreciation. Construction in progress reflects amounts incurred for construction or improvements of property or equipment that have not been placed in service. Construction in progress is transferred to specific property and equipment and depreciated when these assets are ready for their intended use. Depreciation is computed using the straight-line method over the estimated useful lives of the assets, which generally follows:


Asset Category		Useful Lives
Furniture and Fixtures		5 years
Machinery and Equipment		3 to 10 years
Computer Software and Hardware		3 to 5 years
Leasehold improvements		Lesser of the useful life or the term of the respective lease

Upon sale or retirement of assets, the costs and related accumulated depreciation are removed from the consolidated balance sheet and the resulting gain or loss is reflected in operations. Maintenance and repairs are charged to operations as incurred.

Impairment of Long-Lived Assets

The Company reviews long-lived assets for impairment whenever events or changes in circumstances indicate that the carrying amount of an asset may not be recoverable. Recoverability is measured by comparison of the carrying amount to the future undiscounted net cash flows which the assets are expected to generate. If such assets are considered to be impaired, the impairment to be recognized is measured by the amount by which the carrying amount of the assets exceeds the projected discounted future net cash flows arising from the assets. There have been no such impairments of long-lived assets in the years ended December 31, 2022 and 2021.

Research and Development Expenses

Costs related to research, design and development of products are charged to research and development expense as incurred. Research and development costs include, but are not limited to, payroll and personnel expenses, including stock-based compensation, laboratory supplies, outside services and allocated overhead, including rent, depreciation and utilities.

Accrued Research and Development

The Company has entered into various agreements with various third parties, including clinical investigator sites, contract research organizations (“CROs”) and contract manufacturing organizations (“CMOs”), to provide research and development activities. The Company’s accrued research and development costs are estimated based on the level of services performed, including the phase or completion of events, and contracted costs. Accrued clinical trial and related costs are estimated using data such as patient enrollment, clinical site activations or information provided by outside service providers regarding their actual costs incurred. Management determined accrual estimates through reports from and discussions with clinical personnel and outside service providers as to the progress of trials, or the services completed. The estimated costs of research and development provided, but not yet invoiced, are included in accrued and other current liabilities on the consolidated balance sheet. If the actual timing of the performance of services or the level of effort varies from the original estimates, the Company will adjust the accrual accordingly. Payments made to third parties under these arrangements in advance of the performance of the related services are recorded as prepaid expenses or other assets until the services are rendered.

Stock-Based Compensation

The Company accounts for stock-based compensation in accordance with the provisions of ASC 718, Compensation-Stock Compensation. The Company measures stock-based compensation expense for stock options and restricted stock units granted to its employees, directors and non-employees based on the estimated fair value of the awards on the grant date. The fair value of options is calculated using the Black-Scholes valuation model or the Monte Carlo simulation model, which requires the input of subjective assumptions, including (i) the calculation of expected term of the award, (ii) the expected stock price volatility, (iii) the risk-free interest rate, and (iv) expected dividends.

The expected term is calculated using the simplified method, which is available where there is insufficient historical data about exercise patterns and post-vesting employment termination behavior, and equals the midpoint between the vesting date and maximum contractual expiration date.

The expected volatility is estimated based on the Company's historical information for its common stock and supplemented by the historical stock price volatility of a representative peer group over a period equivalent to the expected term of the equity award.

The risk-free interest rate is estimated based on the U.S. Treasury securities with maturity dates commensurate with the expected term of the equity award.

The Company has never paid, and does not expect to pay, dividends in the foreseeable future.

The expense is recorded on a straight-line basis over the requisite service period, which is generally the vesting period, for the entire award. The Company accounts for forfeitures as they occur.

The Company has certain stock options and restricted stock units that vest in conjunction with certain performance conditions. At each reporting date, the Company is required to evaluate whether achievement of the performance conditions is probable. Compensation expense is recorded over the appropriate service period based upon the Company's assessment of accomplishing each performance provision. Refer to Note 12.

Income Taxes

The Company accounts for income taxes under the asset and liability method, which requires, among other things, that deferred income taxes be provided for temporary differences between the tax basis of the Company’s assets and liabilities and their financial statement reported amounts. In addition, deferred tax assets are recorded for the future benefit of utilizing net operating losses (“NOLs”) and research and development credit carryforwards and are measured using the enacted tax rates and laws that will be in effect when such items are expected to reverse. A valuation allowance is provided against deferred tax assets unless it is more likely than not that they will be realized.

The Company accounts for uncertain tax positions by assessing all material positions taken in any assessment or challenge by relevant taxing authorities. Assessing an uncertain tax position begins with the initial determination of the position’s sustainability and is measured at the largest amount of benefit that is greater than fifty percent likely of being realized upon ultimate settlement. The Company’s policy is to recognize interest and penalties related to the underpayment of income taxes as a component of income tax expense or benefit. To date, there have been no interest or penalties charged in relation to the unrecognized tax benefits.

Comprehensive Loss

Comprehensive loss is composed of net loss and other comprehensive income (loss). Other comprehensive income (loss) consists primarily of unrealized gains and losses on debt securities.

Liability related to Sale of Future Royalties

On December 1, 2019, the Company and its subsidiary Kodiak Sciences GmbH entered into a funding agreement with Baker Bros. Advisors, LP (“BBA”), which holds more than 5% of the Company’s stock, pursuant to which BBA purchased the right to receive a capped 4.5% royalty on future net sales of tarcocimab, the Company’s anti-VEGF antibody biopolymer conjugate therapy, in exchange for $225.0 million. Under the terms of the funding agreement, there is no obligation to repay any funding amount received, other than through the capped royalty payments on future product revenues. The Company recorded the funding amount paid by BBA as a liability on the consolidated balance sheet net of issuance costs, in accordance with ASC 730, Research and Development. Under ASC 730, the significant related party relationship between the Company and BBA creates an implicit obligation to repay the funding amount paid to the Company. Once royalty payments to BBA are determined to be probable and estimable, and if such amounts exceed the liability balance, the Company will impute interest to accrete the liability on a prospective basis based on such estimates. If and when the Company makes royalty payments under the funding agreement, it would reduce the liability balance at such time. In July 2021, the funding agreement was amended, at the Company’s request, that the remaining funding amount of $125.0 million would not be paid. Refer to Note 15.

Credit Losses – Available-for-Sale Debt Securities

For available-for-sale debt securities in an unrealized loss position, the Company will periodically assess its portfolio for impairment. The assessment first considers the intent or requirement to sell the security. If either of these criteria are met, the amortized cost basis will be written down to fair value through earnings.

If not met, the Company will evaluate whether the decline resulted from credit losses or other factors by considering the extent to which fair value is less than amortized cost, any changes to the rating of the security by a rating agency, and any adverse conditions specifically related to the security, among other factors. If this assessment indicates that a credit loss exists, the present value of cash flows expected to be collected from the security is compared to the amortized cost basis of the security. If the present value of cash flows expected to be collected is less than the amortized cost basis, a credit loss exists and an allowance for credit losses will be recorded, limited by the amount that the fair value is less than the amortized cost basis. Any impairment that has not been recorded through an allowance for credit losses is recognized in other comprehensive income or loss, as applicable.

Net Loss per Share

Basic net loss per common share is calculated by dividing the net loss attributable to common stockholders by the weighted-average number of common stock outstanding during the period, without consideration of potentially dilutive securities. Diluted net loss per share is computed by dividing the net loss attributable to common stockholders by the weighted-average number of common stock and potentially dilutive securities outstanding for the period. Since the Company has reported net loss for all periods presented, diluted net loss per share is the same as basic net loss per common share for those periods.

Recent accounting pronouncements

From time to time, new accounting pronouncements are issued by the Financial Accounting Standards Board ("FASB"), under its ASC or other standard setting bodies, and adopted by the Company as of the specified effective date. There have been no new accounting pronouncements issued nor adopted during the year ended December 31, 2022 that are of significance to the Company.

Property and Equipment, Net

12 Months Ended

Dec. 31, 2022

Property, Plant and Equipment [Abstract]

Property and Equipment, net

3. Property and Equipment, net

Property and equipment, net consists of the following (in thousands):


	December 31, 2022			December 31, 2021
Furniture and Fixtures	$	1,969		$	214
Machinery and Equipment		12,763			4,672
Computer Software and Hardware		374			289
Leasehold Improvement		43,483			1,285
Construction in Progress		4,519			37,809
Total property and equipment		63,108			44,269
Less: Accumulated depreciation		(6,724	)		(2,939	)
Property and equipment, net	$	56,384		$	41,330

All property and equipment are maintained in the United States and Switzerland. Depreciation expense was $3.8 million, $1.0 million and $0.5 million for the years ended December 31, 2022, 2021 and 2020, respectively.

Accrued Liabilities and Other Current Liabilities

12 Months Ended

Dec. 31, 2022

Accounts Payable and Accrued Liabilities, Current [Abstract]

Accrued Liabilities and Other Current Liabilities

4. Accrued and Other Current Liabilities

Accrued and other current liabilities consist of the following (in thousands):


	December 31, 2022		December 31, 2021
Accrued clinical trial and related costs	$	18,334	$	21,776
Accrued salaries and benefits		6,033		6,187
Accrued manufacturing and research & development costs		5,978		6,041
Accrued leasehold improvements		1,893		13,021
Accrued legal fees		245		403
Accrued professional fees		39		176
Accrued other liabilities		919		715
Total accrued and other current liabilities	$	33,440	$	48,319

Fair Value Measurements

12 Months Ended

Dec. 31, 2022

Fair Value Disclosures [Abstract]

Fair Value Measurements

5. Fair Value Measurements

The following tables present the Company’s fair value hierarchy for assets measured at fair value on a recurring basis (in thousands):


	Fair Value Measurements at December 31, 2022
	Level 1		Level 2		Level 3		Total
Cash equivalents:
Money market funds	$	173,617	$	—	$	—	$	173,617
Marketable securities:
U.S. treasury securities		—	$	288,500		—	$	288,500
Total	$	173,617	$	288,500	$	—	$	462,117

	Fair Value Measurements at December 31, 2021
	Level 1		Level 2		Level 3		Total
Cash equivalents:
Money market funds	$	706,703	$	—	$	—	$	706,703
Total	$	706,703	$	—	$	—	$	706,703

As of December 31, 2022 and 2021, the fair value of the liability related to sale of future royalties is based on our current estimates of future royalties expected to be paid to BBA, which are considered Level 3 inputs. Refer to Note 15. There were no transfers of assets or liabilities between the fair value measurement levels during the years ended December 31, 2022 and 2021.

- Definition

The entire disclosure for the fair value of financial instruments (as defined), including financial assets and financial liabilities (collectively, as defined), and the measurements of those instruments as well as disclosures related to the fair value of non-financial assets and liabilities. Such disclosures about the financial instruments, assets, and liabilities would include: (1) the fair value of the required items together with their carrying amounts (as appropriate); (2) for items for which it is not practicable to estimate fair value, disclosure would include: (a) information pertinent to estimating fair value (including, carrying amount, effective interest rate, and maturity, and (b) the reasons why it is not practicable to estimate fair value; (3) significant concentrations of credit risk including: (a) information about the activity, region, or economic characteristics identifying a concentration, (b) the maximum amount of loss the entity is exposed to based on the gross fair value of the related item, (c) policy for requiring collateral or other security and information as to accessing such collateral or security, and (d) the nature and brief description of such collateral or security; (4) quantitative information about market risks and how such risks are managed; (5) for items measured on both a recurring and nonrecurring basis information regarding the inputs used to develop the fair value measurement; and (6) for items presented in the financial statement for which fair value measurement is elected: (a) information necessary to understand the reasons for the election, (b) discussion of the effect of fair value changes on earnings, (c) a description of [similar groups] items for which the election is made and the relation thereof to the balance sheet, the aggregate carrying value of items included in the balance sheet that are not eligible for the election; (7) all other required (as defined) and desired information.

+ References + Details

Marketable Securities

12 Months Ended

Dec. 31, 2022

Investments, Debt and Equity Securities [Abstract]

Marketable Securities

6. Marketable Securities

The marketable securities are classified as available-for-sale and consist of U.S. treasury securities. The fair value measurement data for marketable securities is obtained from independent pricing services. The Company validates the prices provided by the third-party pricing services by understanding the valuation methods and data sources used and analyzing the pricing data in certain instances.

The following table summarizes the marketable securities (in thousands):


As of December 31, 2022	Amortized Cost		Unrealized Gains		Unrealized Losses			Fair Value
U.S. treasury securities	$	289,807	$	—	$	(1,307	)	$	288,500
Total	$	289,807	$	—	$	(1,307	)	$	288,500

The Company had no marketable securities as of December 31, 2021. All marketable securities held as of December 31, 2022 had effective maturities of less than one year. The unrealized losses for marketable securities related to changes in interest rates. No allowance for credit losses was recorded and no impairment losses were recognized for the year ended December 31, 2022. The Company did not realize any gains or losses recognized on the sale or maturity of available-for-sale debt securities during the year ended December 31, 2022 and as a result, the Company did not reclassify any amounts out of accumulated comprehensive loss.

Derivatives

12 Months Ended

Dec. 31, 2022

Derivative Instruments and Hedging Activities Disclosure [Abstract]

Derivatives

7. Derivatives

Starting 2022, the Company uses certain derivative instruments, that are not designated as hedges for accounting purposes, which include foreign currency forward contracts. The Company uses standard models with market-based inputs which include exchange rate curves of the foreign currency for translating future cash flows. Although these derivatives do not qualify for hedge accounting, the Company believes that such instruments are closely correlated with the underlying exposure, thus managing the associated risk. As of December 31, 2022, these derivatives have been net settled.

Commitments and Contingencies

12 Months Ended

Dec. 31, 2022

Commitments and Contingencies Disclosure [Abstract]

Commitments and Contingencies

8. Commitments and Contingencies

Leases

Palo Alto, California Leases

In June 2020, the Company entered into lease agreements for two buildings at 1200 and 1250 Page Mill Road in Palo Alto, California, which are now the Company’s U.S. corporate offices. The facilities are approximately 82,662 square feet and 72,812 square feet, respectively and include office and laboratory space. For 1200 Page Mill Road, the monthly rent during the initial 6.5-year term will be approximately $0.6 million, with annual year-over-year increases of 3% plus certain operating expenses and taxes and total rent abatement of approximately $7.2 million. The Company has an option to extend the lease term for a period of 6.5 years. For 1250 Page Mill Road, the monthly rent during the initial 13-year term will be approximately $0.5 million, with annual year-over-year increases of 3% plus certain operating expenses and taxes and total rent abatement of approximately $6.3 million. The Landlord will provide a tenant improvement allowance of approximately $1.2 million and $10.6 million for each building, respectively. The Company has two options to extend the lease term for a period of 5 years each. The Company determined that the renewal options were not reasonably certain at lease inception for the two buildings. The Company executed a $10.9 million cash-collateralized letter of credit, which was subsequently reduced to $6.2 million as a result of meeting certain reduction requirements specified therein in 2020. The cash collateralizing the letter of credit is classified as restricted cash on the Company’s consolidated balance sheet. Under ASC 842, the Company classified these leases as operating leases and recorded right-of-use assets and lease liabilities on the lease commencement date. As of December 31, 2022, the Company received a tenant improvement allowance of $10.2 million.

The Company continues to lease office and laboratory space at 2631 Hanover Street in Palo Alto, California. The Company entered into a lease agreement in January 2013 which was amended in March 2016 and extended the lease term until October 2023. The Company classified this lease as an operating lease and recorded a right-of-use asset and lease liability.

Switzerland Lease

In April 2020, the Company entered into a lease agreement for office and laboratory space at Rottenstrasse 5 in Visp, Switzerland. The space is approximately 1,000 square meters. The initial lease term is 5 years, with automatic renewals every 5 years for a maximum lease term of 15 years. The monthly rent during the initial 5-year term will be approximately 32.0 thousand Swiss Francs plus certain operating expenses and taxes. Under ASC 842, the Company classified these leases as operating leases and recorded right-of-use assets and lease liabilities on the lease commencement date.

The maturities of the operating lease liabilities as of December 31, 2022 were as follows (in thousands):


Year ending December 31,	As of December 31, 2022
2023	$	15,592
2024		15,020
2025		15,458
2026		15,909
2027		9,183
Thereafter		46,184
Total undiscounted lease payments		117,346
Less: imputed interest		(28,055	)
Less: future tenant improvement reimbursements		(1,558	)
Total operating lease liabilities	$	87,733

The minimum lease payments above do not include any related common area maintenance charges or real estate taxes. The operating lease expense for the years ended December 31, 2022, 2021 and 2020 were $12.8 million, $12.8 million and $6.1 million, respectively. The weighted-average remaining lease terms and weighted-average discount rates were as follows:


	December 31, 2022			December 31, 2021
Weighted-average remaining lease term (in years)		8.4			8.8
Weighted-average discount rate		6.8	%		6.7	%

Embedded Lease

In August 2020, the Company and its wholly-owned subsidiary Kodiak Sciences GmbH entered into a manufacturing agreement with Lonza Ltd (“Lonza”) for the clinical and commercial supply of drug substance for tarcocimab. A custom-built manufacturing facility is planned to be completed and dedicated to the manufacture of the Company’s drug substance. The manufacturing agreement has an initial term of eight years, and the Company has the right to extend the term up to a total of 16 years. The Company and Lonza each has the ability to terminate this agreement upon the occurrence of certain conditions.

In April 2021, the agreement was amended to provide for higher annual manufacturing capacity. The Company expanded and finalized the design and scope of the bioconjugate manufacturing facility with a revised estimated capital contribution of approximately 75.0 million Swiss Francs of which the Company has paid 40.0 million Swiss Francs of the capital contribution, equivalent to 44.1 million U.S. Dollars, which is recorded in other assets on the consolidated balance sheet as of December 31, 2022. Over the period from 2022 through 2029, manufacturing payments totaling approximately 150.0 million Swiss Francs may be incurred for potential commercial supply of tarcocimab drug substance. These commitments are not included in the operating lease liabilities table above.

The Company concluded that this agreement contains an embedded lease as the custom-built manufacturing suite will be dedicated for the Company’s use. As of December 31, 2022, the Company did not have control of this manufacturing space and therefore, did not record a right-of-use asset and corresponding lease liability. On January 31, 2023, the custom-built manufacturing suite was commissioned as a cGMP facility and the right-of-use asset and corresponding lease liability were subsequently recorded.

Manufacturing Agreements

The Company has entered into service and equipment purchase agreements in the normal course of business with various providers, pursuant to which such providers agreed to perform activities in connection with the manufacturing process of certain materials. These agreements, and any related amendments, state that planned activities and purchases that are included in the signed work orders are, in some cases, binding and, hence, obligate the Company to pay the full price of the work order upon satisfactory delivery of products and services or obligate the Company to the binding amount regardless of whether such planned activities are in fact performed. Per the terms of the agreements, the Company has the option to cancel signed orders at any time upon written notice, which may or may not be subject to payment of a cancellation fee. The level of cancellation fees may be dependent on the timing of the written notice in relation to the commencement date of the work, with the maximum cancellation amount dependent on the agreement or the work order.

As of December 31, 2022 and 2021, the total amount of contractual obligations related to these manufacturing agreements that are subject to cancellation fees, including accrued amounts, were $56.8 million and $69.5 million, respectively. These amounts represent our minimal contractual obligations, excluding the commitments under the embedded lease arrangement. Purchases under these manufacturing agreements for the years ended December 31, 2022, 2021 and 2020 were $47.4 million, $31.8 million and $16.8 million, respectively. As of December 31, 2022, the Company had not incurred any cancellation fees under the manufacturing agreements.

Other Funding Commitments

In the normal course of business, the Company enters into agreements with third-parties for services to be provided to the Company. Generally, these agreements provide for termination upon notice, with specified amounts due upon termination based on the timing of termination and the terms of the agreement. The actual amounts and timing of payments under these agreements are uncertain and contingent upon the initiation and completion of services to be provided to the Company.

The Company has also entered into various cancellable license agreements for certain technology. The Company may be obligated to make payments on future sales of specified products associated with such license agreements. Such payments are dependent on future product sales and are not estimable.

Tenant Improvement Allowance Payable

In March 2016, the Company entered into a lease amendment, under which the Company is allowed to draw down an additional allowance of $0.4 million for tenant improvements related to the office lease over the period from the execution of the agreement to October 2023. The interest rate is 8% per year over 10 years. Principal and interest are payable on the first day of every month.

As of December 31, 2022 and 2021, the current portion of the tenant improvement allowance payable in accrued and other current liabilities was less than $0.1 million and less than $0.1 million, respectively. As of December 31, 2022 and 2021, the non-current portion of the tenant improvement allowance payable in other liabilities was $0.2 million and $0.2 million, respectively.

Legal Proceedings

From time to time, the Company may become involved in legal proceedings arising from the ordinary course of its business. Management is currently not aware of any matters that could have a material adverse effect on the Company’s financial position, results of operations or cash flows. The Company records a legal liability when it believes that it is both probable that a liability may be imputed, and the amount of the liability can be reasonably estimated. Significant judgment by the Company is required to determine both probability and the estimated amount.

Indemnification

To the extent permitted under Delaware law, the Company has agreed to indemnify its directors and officers for certain events or occurrences while the director or officer is, or was serving, at the Company’s request in such capacity. The indemnification period covers all pertinent events and occurrences during the director’s or officer’s service. The maximum potential amount of future payments the Company could be required to make under these indemnification agreements is not specified in the agreements; however, the Company has director and officer insurance coverage that reduces its exposure and enables the Company to recover a portion of any future amounts paid. The Company believes the estimated fair value of these indemnification agreements in excess of applicable insurance coverage is minimal.

Income Taxes

12 Months Ended

Dec. 31, 2022

Income Tax Disclosure [Abstract]

Income Taxes

9. Income Taxes

The components of loss before income taxes were as follows (in thousands):


	Year Ended December 31, 2022			Year Ended December 31, 2021			Year Ended December 31, 2020
United States	$	(163,240	)	$	(46,590	)	$	(17,273	)
Foreign		(170,550	)		(220,326	)		(115,809	)
Total loss before income taxes	$	(333,790	)	$	(266,916	)	$	(133,082	)

The provision (benefit) for income taxes consists of the following (in thousands):


	Year Ended December 31, 2022		Year Ended December 31, 2021		Year Ended December 31, 2020
Current:
Federal	$	—	$	—	$	—
State		—		—		—
Foreign		33		74		14
Total current		33		74		14

Deferred:
Federal		—		—		—
State		—		—		—
Foreign		—		—		—
Total deferred		—		—		—
Provision (Benefit) for income taxes	$	33	$	74	$	14

The tax effects of temporary differences that give rise to significant components of the net deferred tax assets are as follows (in thousands):


	December 31, 2022			December 31, 2021			December 31, 2020
Deferred tax assets:
Net operating loss carryforwards	$	117,232		$	75,259		$	28,451
Intangible assets		166,259			166,269			12,088
Research and development tax credits		25,110			18,330			10,527
Stock-based compensation		23,576			10,823			8,405
Accruals		1,562			1,532			1,367
Operating lease liability		25,548			23,142			22,276
Property and equipment		—			—			127
Sec. 174 Capitalized R&D		7,914			—			—
Total deferred tax assets		367,201			295,355			83,241
Valuation allowance		(347,789	)		(275,788	)		(62,005	)
Net deferred tax assets		19,412			19,567			21,236
Deferred tax liabilities:
Operating lease right-of-use asset		(17,073	)		(19,217	)		(21,234	)
Capitalized legal fees		—			—			(2	)
Property and equipment		(2,339	)		(350	)		—
Total deferred tax liabilities		(19,412	)		(19,567	)		(21,236	)
Total net deferred tax assets	$	—		$	—		$	—

The Company has recorded a full valuation allowance against its net deferred tax assets due to the uncertainty as to whether such assets will be realized. The net change in the total valuation allowance for the years ended December 31, 2022, 2021 and 2020 was an increase of approximately $72.0 million, $213.8 million and $24.8 million, respectively.

The Tax Cuts and Jobs Act eliminated the option to deduct research and development expenditures currently and requires taxpayers to capitalize and amortize them pursuant to Internal Revenue Code Section 174 beginning in 2022. The capitalized expenses are amortized over a 5-year period for domestic expenses and a 15-year period for foreign expenses.

NOLs and tax credit carry-forwards are subject to review and possible adjustment by the Internal Revenue Service (“IRS”) and may become subject to an annual limitation in the event of certain cumulative changes in the ownership interest of significant shareholders over a three-year period in excess of 50% as defined under Sections 382 and 383 in the Internal Revenue Code, which could limit the amount of tax attributes that can be utilized annually to offset future taxable income or tax liabilities. The amount of the annual limitation is determined based on the Company’s value immediately prior to the ownership change. The Company periodically completes a Section 382 analysis. Subsequent ownership changes since the most recent study may further affect the limitation in future years.

As of December 31, 2022, the Company had $68.7 million of federal and $614.9 million of state net operating loss available to offset future taxable income. A portion of the federal net operating loss carryforwards begin to expire in 2035 and the state net operating loss carryforwards begin to expire in 2035, if not utilized. $50.6 million of the federal net operating loss are not subject to expiration.

As of December 31, 2022, the Company also had federal and state research and development credit carryforwards of approximately $24.6 million and $8.1 million, respectively. The federal research and development credit carryforwards expire beginning 2035. The California tax credit can be carried forward indefinitely.

On March 27, 2020, the President signed into law the Coronavirus Aid, Relief, and Economic Security Act, or the CARES Act, an economic stimulus package in response to the COVID-19 global pandemic and the Families First Coronavirus Response Act, or FFCR Act, which permits employees of certain organizations paid sick time stemming from COVID-19-related issues. The CARES Act contains several corporate income tax provisions, including making remaining alternative minimum tax credits immediately refundable; providing a 5-year carryback of NOLs generated in tax years 2018, 2019, and 2020, and removing the 80% taxable income limitation on utilization of those NOLs if carried back to prior tax years or utilized in tax years beginning before 2021; temporarily liberalizing the interest deductibility rules under Section 163(j) of the CARES Act, by raising the adjusted taxable income limitation from 30% to 50% for tax years 2019 and 2020 and giving taxpayers the election of using 2019 adjusted taxable income for purposes of computing 2020 interest deductibility. The CARES Act did not have a material impact on the Company’s tax provision for the years ended December 31, 2022, 2021, or 2020.

The Consolidated Appropriations Act, 2021, which was enacted on December 27, 2020, has expanded, extended, and clarified selected CARES Act provisions, specifically on Paycheck Protection Program loans and Employee Retention Tax Credits, 100% deductibility of business meals as well as other tax extenders. The Consolidated Appropriations Act did not have a material impact on the Company’s tax provision for the years ended December 31, 2022, 2021, or 2020.

California Assembly Bill 85 (AB 85) was signed into law by Governor Gavin Newsom on June 29, 2020. The legislation suspends the California NOL deductions for 2022, 2021, and 2020 for certain taxpayers and imposes a limitation on certain California tax credits for 2022, 2021, and 2020. The legislation disallows the use of California NOL deductions if the taxpayer recognizes business income and its adjusted gross income is greater than $1,000,000. The carryover periods for NOL deductions disallowed by this provision will be extended. Additionally, any business credit will only offset a maximum of $5,000,000 of California tax. Given the Company’s taxable loss position, this legislation did not impact the tax provision for the years ended December 31, 2022, 2021, or 2020.

California Senate Bill 113 (SB 113), was signed into law by Governor Newsom on February 9, 2022. The legislation contains important California tax law changes, including reinstatement of business tax credits and net NOL deductions limited by AB 85 mentioned above. Given the Company’s taxable loss position, this legislation did not impact the tax provision for the years ended December 31, 2022.

A reconciliation of the Company’s effective tax rate to the statutory U.S. federal rate is as follows:


	December 31, 2022			December 31, 2021			December 31, 2020
Federal statutory income tax rate		21.0	%		21.0	%		21.0	%
State taxes		5.8			6.7			4.3
Foreign tax rate differential		(4.7	)		(7.7	)		(7.9	)
Change in valuation allowance		(20.0	)		(78.3	)		(17.3	)
Stock-based compensation		(3.9	)		(1.2	)		6.7
Research tax credit		1.8			2.4			3.8
Sale of future royalties		—			0.1			(9.4	)
Section 162(m)		—			(0.8	)		(1.2	)
Intangible valuation		—			57.8			—
Provision for income taxes		0.0	%		0.0	%		0.0	%

The Company recognizes benefits of uncertain tax positions if it is more likely than not that such positions will be sustained upon examination based solely on their technical merits, as the largest amount of benefit that is more likely than not to be realized upon the ultimate settlement. As of December 31, 2022, 2021 and 2020, none of the unrecognized tax benefits would affect income tax expense with consideration of the valuation allowance. The Company does not anticipate the uncertain tax positions will materially change in the next 12 months. The Company’s policy is to recognize interest and penalties related to the underpayment of income taxes as a component of income tax expense or benefit. To date, there have been no interest or penalties charged in relation to the unrecognized tax benefits.

The beginning and ending unrecognized tax benefits amounts are as follows (in thousands):


	December 31, 2022		December 31, 2021		December 31, 2020
Unrecognized tax benefits at beginning of period	$	6,729	$	4,650	$	1,838
Increases related to current year tax positions		849		2,079		2,812
Unrecognized tax benefits at end of period	$	7,578	$	6,729	$	4,650

The Company files income tax returns in the United States and Switzerland. The Company is not currently under examination by income tax authorities in federal, state or other jurisdictions. All tax returns remain open for examination by the federal and state authorities for three and four years, respectively, from the date of utilization of any net operating loss or credits.

- Definition

The entire disclosure for income taxes. Disclosures may include net deferred tax liability or asset recognized in an enterprise's statement of financial position, net change during the year in the total valuation allowance, approximate tax effect of each type of temporary difference and carryforward that gives rise to a significant portion of deferred tax liabilities and deferred tax assets, utilization of a tax carryback, and tax uncertainties information.

+ References

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-Publisher FASB
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+ Details

Preferred Stock

12 Months Ended

Dec. 31, 2022

Equity [Abstract]

Preferred Stock

10. Preferred Stock

As of December 31, 2022 and 2021, the Company’s amended and restated certificate of incorporation authorized the Company to issue up to 10,000,000 shares of preferred stock at the par value of $0.0001 per share. As of December 31, 2022, there are no shares of the Company’s preferred stock issued or outstanding.

Common Stock

12 Months Ended

Dec. 31, 2022

Equity [Abstract]

Common Stock

11. Common Stock

As of December 31, 2022 and 2021, the Company’s amended and restated certificate of incorporation authorized the Company to issue 490,000,000 shares of common stock at the par value of $0.0001 per share. Each share of common stock is entitled to one vote. The board of directors may declare and pay dividends to holders of common stock. The Company has never declared or paid any dividends on common stock.

The Company had reserved common stock for future issuances as follows:


	December 31, 2022		December 31, 2021
Exercise of options outstanding and release of restricted shares		16,822,629		14,887,847
Exercise of common stock warrants outstanding		—		250,000
Issuance of common stock under the 2018 Equity Incentive Plan		1,934,606		2,101,369
Issuance of common stock under the 2018 Employee Share Purchase Plan		425,179		453,042
Total		19,182,414		17,692,258

- Definition

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

+ References

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Reference 12: http://www.xbrl.org/2003/role/disclosureRef
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+ Details

Stock-Based Compensation

12 Months Ended

Dec. 31, 2022

Share-Based Payment Arrangement [Abstract]

Stock-Based Compensation

12. Stock-Based Compensation

2018 Equity Incentive Plan

In August 2018, the Company adopted the 2018 Equity Incentive Plan (“2018 Plan”), which became effective on the business day prior to the effectiveness of the registration statement relating to the IPO. The 2018 Plan initially reserved 4,300,000 shares of common stock for the issuance of incentive stock options ("ISOs"), nonstatutory stock options ("NSOs"), restricted stock, restricted stock units (“RSUs”), stock appreciation rights, performance units and performance shares to employees, directors and consultants of the Company. The number of shares available for issuance increases annually on the first day of each fiscal year equal to the least of (1) 4,300,000 shares, and (2) 4% of outstanding shares of common stock as of the last day of the immediately preceding year, and (3) such other amount as determined by the board of directors. The exercise price of options must be equal to at least the fair market value of the common stock on the grant date. For ISOs, the term may not exceed ten years, except in respect to any participant with more than 10% of voting power of all classes or stock then the term may not exceed five years and the exercise price must be equal to at least 110% of the fair market value of the common stock on the grant date. Options and RSUs granted generally vest over four years.

The number of shares available for issuance increased by 2,073,050 shares in 2022 and there were 1,934,606 shares available for grant under the 2018 Plan as of December 31, 2022.

2021 Long-Term Performance Incentive Plan

The 2021 Long-Term Performance Incentive Plan (“2021 LTPIP”) was designed to be a long-term, pay-for-performance, incentive plan that would further align the interests of management and other eligible employees with the creation of substantial long-term value for the Company's stockholders. During 2021, eligible employees were provided a one-time opportunity to "opt-in" and forgo a portion of their annual equity incentive awards in exchange for a one-time grant of performance-based stock options from the 2021 LTPIP and 2018 Plan, collectively referred to as the "LTPIP Program". There were no options granted under the LTPIP Program for the year ended December 31, 2022.

Shares underlying the options granted under the LTPIP Program may be earned based on the achievement of the performance-based requirement based on stock price goals and/or certain operational milestones based on approval by the U.S. Food and Drug Administration of a Biologics License Application in respect of a first, second, and third major indication and based on sales. The performance-based requirement and operational milestones were not achieved as of December 31, 2022.

The Company determined the exchange of the original award of annual equity incentive awards with the modified award of options granted under the LTPIP Program represented a change in the original terms and conditions. The modification resulted in additional compensation cost equal to the incremental value between the original and modified awards to be recognized. For the annual equity incentive awards, the Company continues to record the unrecognized compensation expense over the original vesting period. For the options granted under the LTPIP Program, the stock-based compensation expense recognized during the years ended December 31, 2022 and 2021 was $65.1 million and $15.7 million, respectively.

As of December 31, 2022, there was $247.9 million of unrecognized stock-based compensation expense related to the 6,818,584 options granted under the LTPIP Program, but not yet earned or vested, to be recognized over a weighted-average period of 4.02 years.

Stock Options

Stock option activity, including stock options and PSOs under the 2021 LTPIP, 2018 Plan and 2015 Plan is summarized as follows:


	Number of Options			Weighted Average Exercise Price		Weighted Average Remaining Contractual Term (in years)		Aggregate Intrinsic Value (in thousands)
Outstanding at December 31, 2021		14,523,917		$	61.68		8.60	$	335,440
Granted		3,079,120		$	8.99
Exercised		(126,999	)	$	13.93
Forfeited or canceled		(933,931	)	$	75.23
Outstanding at December 31, 2022		16,542,107		$	51.48		7.91	$	5,410
Shares exercisable December 31, 2022		8,452,058		$	41.84		7.03	$	5,390
Vested and expected to vest December 31, 2022		16,542,107		$	51.48		7.91	$	5,410

The weighted-average grant date fair value of the time-vested stock options granted for 2022, 2021 and 2020 was $6.31, $51.55 and $32.44 per share, respectively. The total intrinsic value of stock options exercised during 2022, 2021 and 2020 was $6.1 million, $40.2 million, and $58.1 million, respectively. The intrinsic value represents the amount by which the market price of the underlying stock exceeds the exercise price of an option.

Employee Stock Options

The Company estimated the fair value of employee stock options using the Black-Scholes valuation model. The fair value of time-vested employee stock options was estimated using the following weighted-average assumptions:


	Year Ended December 31,
	2022			2021			2020
Expected volatility		83	%		61	%		66	%
Risk-free interest rate		2.86	%		1.03	%		0.39	%
Dividend yield		0	%		0	%		0	%
Expected term		5.98			6.25			6.00

The Company granted 3,079,120 options to employees in 2022. The total fair value of employee options vested during the years ended December 31, 2022, 2021 and 2020 was $28.9 million, $26.9 million and $19.7 million, respectively. Stock-based compensation expense recognized during the years ended December 31, 2022, 2021 and 2020 for options granted to employees, including the options granted under the LTPIP Program, was $93.8 million, $44.1 million and $20.8 million, respectively.

Restricted Shares

Restricted share activity, including restricted stock units (“RSUs”), and performance-based restricted stock units (“PSUs”), under the 2018 Plan is summarized as follows:


	Number of Restricted Shares			Weighted Average Grant Date Fair Value
Unvested at December 31, 2021		363,930		$	72.75
Granted		67,750			20.71
Vested		(103,032	)		71.06
Canceled		(48,126	)		76.44
Unvested at December 31, 2022		280,522		$	60.17

Employee Restricted Stock Units

The Company granted 67,750 RSUs to employees in 2022. The total fair value of RSUs vested during the year ended December 31, 2022, 2021, and 2020 was $4.9 million, $3.2 million and $0.3 million, respectively. Stock-based compensation expense recognized during the years ended December 31, 2022, 2021 and 2020 for RSUs was $4.6 million, $4.4 million, and $1.9 million, respectively.

Non-Employee Awards

The Company granted no stock options or RSUs to non-employees during the year ended December 31, 2022. The fair value of non-employee stock options was estimated using the following weighted-average assumptions:


	Year Ended December 31,
	2021			2020
Expected volatility		60	%		67	%
Risk-free interest rate		0.97	%		0.36	%
Dividend yield		0	%		0	%
Expected term		5.69			5.56

Stock-based compensation expense recognized during the years ended December 31, 2022, 2021 and 2020 for equity awards granted to non-employees was $1.2 million, $1.2 million and $0.7 million, respectively.

Performance-Based Awards

In December 2019, the Company granted 170,150 performance-based stock options and 128,900 performance-based RSUs (collectively "2019 PSA"). These equity awards would vest 25% upon the achievement of specific clinical development milestones. The remaining awards would then vest in three equal annual installments after that date. The performance criteria for 2019 PSA was achieved in June 2021. 42,536 of the performance-based stock options and 25,907 of the performance-based restricted stock vested during 2022. The total fair value of the performance-based stock options and RSUs vested during the years ended December 31, 2022 was $3.9 million.

The Company estimated the fair value of the 2019 PSA using the Black-Scholes valuation model and significant assumptions included an expected volatility of 72%, a risk-free rate of 1.67%, expected dividend yield of 0%, and expected term of 6.31 years.

In February 2021, the Company granted 190,831 performance-based stock options ("2021 Feb PSO"). These stock options will vest 25% upon the achievement of specific clinical development milestones. The remaining awards would then vest in 36 successive equal monthly installments after the performance criteria is achieved. The performance criteria for 2021 PSOs was achieved in February 2022. 80,456 of the performance-based stock options vested during 2022. The total fair value of the performance-based stock options vested during the year ended December 31, 2022 was $6.2 million.

The Company estimated the fair value of the 2021 Feb PSO using the Black-Scholes valuation model. Significant assumptions utilized in estimating the fair value of 2021 Feb PSO include an expected volatility of 66%, a risk-free rate of 0.66%, expected dividend yield of 0%, and expected term of 5.94 years.

In August 2021, the Company granted 478,750 performance-based stock options ("2021 Aug PSO"). These stock options will vest upon the achievement of specific clinical development milestones with the percentage of shares earned being dependent on the relative total stockholder return over the performance period. The remaining shares will then vest in 12 successive equal monthly installments after the performance criteria is achieved. As of December 31, 2022, the requisite performance criteria for the 2021 Aug PSO was not achieved and not probable and no stock-based compensation expense was recognized during the year ended December 31, 2022.

The Company estimated the weighted-average fair value of the 2021 Aug PSO using the Monte Carlo simulation model. Significant assumptions utilized in estimating the fair value of 2021 Aug PSO include an expected volatility of 60%, a risk-free rate of 1.05%, expected dividend yield of 0%, and expected term of 6.49 years.

Performance-based awards are recorded as expense beginning when vesting events are determined to be probable. Stock-based compensation expense recognized during the years ended December 31, 2022, 2021 and 2020 for the performance-based equity awards was $6.3 million, $11.4 million and $7.2 million, respectively.

2018 Employee Share Purchase Plan

In August 2018, the Company adopted the 2018 Employee Share Purchase Plan (“ESPP”), which became effective on the business day prior to the effectiveness of the registration statement relating to the IPO. A total of 460,000 shares of common stock were initially reserved for issuance under the ESPP. The initial offering period of the ESPP was authorized by the Company’s board of directors and commenced on January 4, 2021. Each offering period is twelve months long, with two purchase periods. ESPP participants will purchase shares of common stock at a price per share equal to 85% of the lesser of (1) the fair market value per share of the common stock on the enrollment date or (2) the fair market value of the common stock on the exercise date.

The Company issued 27,863 shares under the ESPP during the year ended December 31, 2022. Stock-based compensation expense recognized during the year ended December 31, 2022 and 2021 for the ESPP was $0.2 million and $0.3 million, respectively.

Stock-Based Compensation Expense

Stock-based compensation is classified in the consolidated statements of operations and comprehensive loss as follows (in thousands):


	Year Ended December 31,
	2022		2021		2020
Research and development	$	59,288	$	33,237	$	16,957
General and administrative		46,745		28,148		13,711
Total stock-based compensation	$	106,033	$	61,385	$	30,668

As of December 31, 2022, the Company had $311.3 million of unrecognized compensation expense related to unvested share-based awards including options granted under the LTPIP Program and ESPP, which is expected to be recognized over a weighted-average period of 3.61 years.

Shares Subject to Repurchase

The Company has a right of repurchase with respect to unvested shares issued upon early exercise of options at an amount equal to the lower of (1) the exercise price of each restricted share being repurchased and (2) the fair market value of such restricted share at the time the Company’s right of repurchase is exercised. The Company’s right to repurchase these shares lapses as those shares vest over the requisite service period.

Shares purchased by employees pursuant to the early exercise of stock options are not deemed, for accounting purposes, to be issued until those shares vest according to their respective vesting schedules. Cash received for early exercised stock options is recorded as accrued liabilities and other current liabilities on the consolidated balance sheet and is reclassified to common stock and additional paid-in capital as such shares vest. At December 31, 2022, there were no early exercised stock options subject to the Company’s right of repurchase.

Net Loss per Share Attributable to Common Stockholders

12 Months Ended

Dec. 31, 2022

Earnings Per Share [Abstract]

Net Loss per Share Attributable to Common Stockholders

13. Net Loss per Common share

The following table sets forth the computation of basic and diluted net loss per share attributable to common stockholders which excludes shares which are legally outstanding, but subject to repurchase by the Company (in thousands, except share and per share data):


	Year Ended December 31,
	2022			2021			2020
Numerator:
Net loss attributable to common stockholders	$	(333,823	)	$	(266,990	)	$	(133,096	)
Denominator:
Weighted-average shares outstanding used in computing net loss per share attributable to common stockholders, basic and diluted		52,249,620			51,788,918			45,741,845
Net loss per share attributable to common stockholders, basic and diluted	$	(6.39	)	$	(5.16	)	$	(2.91	)

The following common share equivalents were excluded from the computation of diluted net loss per common share for the periods presented because their inclusion would have been antidilutive:


	As of December 31,
	2022		2021		2020
Outstanding stock options		16,542,107		14,523,917		6,897,276
Unvested restricted shares		280,522		363,930		359,945
Total		16,822,629		14,887,847		7,257,221

401(k) Plan

12 Months Ended

Dec. 31, 2022

Retirement Benefits [Abstract]

401(k) plan

14. 401(k) Plan

In 2011, the Company adopted a 401(k) retirement and savings plan covering all employees. The 401(k) plan allows employees to make pre- and post-tax contributions up to the maximum allowable amount set by the Internal Revenue Service. The 401(k) plan was amended to include an employer matching provision in 2019. The Company will make matching contributions of 100% of employee contributions up to a maximum of 50% of the individual maximum contribution limit allowed under the IRS rules. For the years ended December 31, 2022, 2021 and 2020, the expense related to the matching contributions was $0.9 million, $0.7 million and $0.6 million, respectively.

- Definition

The entire disclosure for retirement benefits.

+ References

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
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Reference 2: http://www.xbrl.org/2003/role/disclosureRef
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Reference 3: http://www.xbrl.org/2003/role/disclosureRef
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Reference 7: http://www.xbrl.org/2003/role/disclosureRef
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Reference 8: http://www.xbrl.org/2003/role/disclosureRef
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Reference 9: http://www.xbrl.org/2003/role/disclosureRef
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+ Details

Liability Related to Sale of Future Royalties

12 Months Ended

Dec. 31, 2022

15. Liability related to Sale of Future Royalties

On December 1, 2019, the Company and its subsidiary Kodiak Sciences GmbH entered into a funding agreement with BBA, which holds more than 5% of the Company’s capital stock, pursuant to which BBA purchased the right to receive a capped 4.5% royalty on future net sales of tarcocimab, the Company’s anti-VEGF antibody biopolymer conjugate therapy, in exchange for $225.0 million. The royalty terminates upon the date that BBA has received an aggregate amount equal to 4.5 times the funding amount paid to the Company, unless earlier terminated or repurchased by the Company. Under the terms of the funding agreement, there is no obligation to repay any funding amount received, other than through the capped royalty payments on future product revenues. The Company has the option, exercisable at any point during the term of the funding agreement, to repurchase 100% of the royalties due to BBA for a purchase price equal to 4.5 times the funding amount paid to the Company as of such time, less amounts paid by the Company to BBA.

The closing of the funding agreement was subject to certain conditions and occurred in February 2020. The Company received $100.0 million of the funding on February 4, 2020. The remaining $125.0 million, subject to delivery of notice by the Company, was payable upon enrollment of 50% of the patients in the RVO clinical program. In July 2021, the funding agreement was amended, at the Company’s request, that the remaining funding amount of $125.0 million would not be paid.

The Company recorded the initial $100.0 million payment as a liability on the consolidated balance sheet net of issuance costs. Once royalty payments to BBA are determined to be probable and estimable, and if such amounts exceed the liability balance, the Company will impute interest to accrete the liability on a prospective basis based on such estimates. If and when the Company makes royalty payments under the funding agreement, it would reduce the liability balance at such time. As of December 31, 2022, royalty payments are not probable and estimable.

For the years ended December 31, 2022 and 2021, no interest expense was recognized for the liability related to the sale of future royalties.

Summary of Significant Accounting Policies (Policies)

12 Months Ended

Dec. 31, 2022

Accounting Policies [Abstract]

Basis of Presentation

The accompanying consolidated financial statements have been prepared in accordance with accounting principles generally accepted in the United States of America (“US GAAP”).

Reclassification

Certain prior period amounts in the consolidated financial statements have been reclassified to conform to the current period presentation.

Principles of Consolidation

Segments

Use of Estimates

Risk and Uncertainties

Concentration of Credit Risk

Cash and Cash Equivalents

The Company considers all highly liquid investments with stated maturities of three months or less at the date of purchase to be cash equivalents.

Marketable Securities

Restricted Cash

Derivatives and Hedging

Fair Value Measurements

Fair Value of Financial Instruments

Level 1—Observable inputs, such as quoted prices in active markets for identical assets or liabilities at the measurement date.

Leases

Property and Equipment, Net


Asset Category		Useful Lives
Furniture and Fixtures		5 years
Machinery and Equipment		3 to 10 years
Computer Software and Hardware		3 to 5 years
Leasehold improvements		Lesser of the useful life or the term of the respective lease

Impairment of Long-Lived Assets

Research and Development Expenses

Accrued Research And Development

Accrued Research and Development

Stock-Based Compensation

The risk-free interest rate is estimated based on the U.S. Treasury securities with maturity dates commensurate with the expected term of the equity award.

The Company has never paid, and does not expect to pay, dividends in the foreseeable future.

The expense is recorded on a straight-line basis over the requisite service period, which is generally the vesting period, for the entire award. The Company accounts for forfeitures as they occur.

Income Taxes

Comprehensive Loss

Comprehensive loss is composed of net loss and other comprehensive income (loss). Other comprehensive income (loss) consists primarily of unrealized gains and losses on debt securities.

Credit Losses – Available-for-Sale Debt Securities

Net Loss per Share Attributable to Common Stockholders

Net Loss per Share

Recent Accounting Pronouncements

Recent accounting pronouncements

Summary of Significant Accounting Policies (Tables)

12 Months Ended

Dec. 31, 2022

Accounting Policies [Abstract]

Schedule of Property Plant and Equipment Estimated Useful Lives

Depreciation is computed using the straight-line method over the estimated useful lives of the assets, which generally follows:


Asset Category		Useful Lives
Furniture and Fixtures		5 years
Machinery and Equipment		3 to 10 years
Computer Software and Hardware		3 to 5 years
Leasehold improvements		Lesser of the useful life or the term of the respective lease

Property and Equipment, Net (Tables)

12 Months Ended

Dec. 31, 2022

Property, Plant and Equipment [Abstract]

Summary of Property and Equipment, net

Property and equipment, net consists of the following (in thousands):


	December 31, 2022			December 31, 2021
Furniture and Fixtures	$	1,969		$	214
Machinery and Equipment		12,763			4,672
Computer Software and Hardware		374			289
Leasehold Improvement		43,483			1,285
Construction in Progress		4,519			37,809
Total property and equipment		63,108			44,269
Less: Accumulated depreciation		(6,724	)		(2,939	)
Property and equipment, net	$	56,384		$	41,330

Accrued Liabilities and Other Current Liabilities (Tables)

12 Months Ended

Dec. 31, 2022

Accounts Payable and Accrued Liabilities, Current [Abstract]

Schedule of Accrued Liabilities and Other Current Liabilities

Accrued and other current liabilities consist of the following (in thousands):


	December 31, 2022		December 31, 2021
Accrued clinical trial and related costs	$	18,334	$	21,776
Accrued salaries and benefits		6,033		6,187
Accrued manufacturing and research & development costs		5,978		6,041
Accrued leasehold improvements		1,893		13,021
Accrued legal fees		245		403
Accrued professional fees		39		176
Accrued other liabilities		919		715
Total accrued and other current liabilities	$	33,440	$	48,319

Fair Value Measurements (Tables)

12 Months Ended

Dec. 31, 2022

Fair Value Disclosures [Abstract]

Summary of Fair Value Hierarchy for Assets and Liabilities Measured at Fair Value on Recurring Basis

The following tables present the Company’s fair value hierarchy for assets measured at fair value on a recurring basis (in thousands):


	Fair Value Measurements at December 31, 2022
	Level 1		Level 2		Level 3		Total
Cash equivalents:
Money market funds	$	173,617	$	—	$	—	$	173,617
Marketable securities:
U.S. treasury securities		—	$	288,500		—	$	288,500
Total	$	173,617	$	288,500	$	—	$	462,117

	Fair Value Measurements at December 31, 2021
	Level 1		Level 2		Level 3		Total
Cash equivalents:
Money market funds	$	706,703	$	—	$	—	$	706,703
Total	$	706,703	$	—	$	—	$	706,703

Marketable Securities (Tables)

12 Months Ended

Dec. 31, 2022

Investments, Debt and Equity Securities [Abstract]

Summary of Marketable Securities Held

The following table summarizes the marketable securities (in thousands):


As of December 31, 2022	Amortized Cost		Unrealized Gains		Unrealized Losses			Fair Value
U.S. treasury securities	$	289,807	$	—	$	(1,307	)	$	288,500
Total	$	289,807	$	—	$	(1,307	)	$	288,500

Commitments and Contingencies (Tables)

12 Months Ended

Dec. 31, 2022

Commitments and Contingencies Disclosure [Abstract]

Summary of Maturities of Operating Lease Liabilities

The maturities of the operating lease liabilities as of December 31, 2022 were as follows (in thousands):


Year ending December 31,	As of December 31, 2022
2023	$	15,592
2024		15,020
2025		15,458
2026		15,909
2027		9,183
Thereafter		46,184
Total undiscounted lease payments		117,346
Less: imputed interest		(28,055	)
Less: future tenant improvement reimbursements		(1,558	)
Total operating lease liabilities	$	87,733

Summary of Lessee, Weighted Average Remaining Lease Term and Weighted Average Discount Rates

The weighted-average remaining lease terms and weighted-average discount rates were as follows:


	December 31, 2022			December 31, 2021
Weighted-average remaining lease term (in years)		8.4			8.8
Weighted-average discount rate		6.8	%		6.7	%

Income Taxes (Tables)

12 Months Ended

Dec. 31, 2022

Income Tax Disclosure [Abstract]

Components of Loss before Income Taxes

The components of loss before income taxes were as follows (in thousands):


	Year Ended December 31, 2022			Year Ended December 31, 2021			Year Ended December 31, 2020
United States	$	(163,240	)	$	(46,590	)	$	(17,273	)
Foreign		(170,550	)		(220,326	)		(115,809	)
Total loss before income taxes	$	(333,790	)	$	(266,916	)	$	(133,082	)

Schedule of Provision (Benefit) for Income Taxes

The provision (benefit) for income taxes consists of the following (in thousands):


	Year Ended December 31, 2022		Year Ended December 31, 2021		Year Ended December 31, 2020
Current:
Federal	$	—	$	—	$	—
State		—		—		—
Foreign		33		74		14
Total current		33		74		14

Deferred:
Federal		—		—		—
State		—		—		—
Foreign		—		—		—
Total deferred		—		—		—
Provision (Benefit) for income taxes	$	33	$	74	$	14

Components of Deferred Tax Assets

The tax effects of temporary differences that give rise to significant components of the net deferred tax assets are as follows (in thousands):


	December 31, 2022			December 31, 2021			December 31, 2020
Deferred tax assets:
Net operating loss carryforwards	$	117,232		$	75,259		$	28,451
Intangible assets		166,259			166,269			12,088
Research and development tax credits		25,110			18,330			10,527
Stock-based compensation		23,576			10,823			8,405
Accruals		1,562			1,532			1,367
Operating lease liability		25,548			23,142			22,276
Property and equipment		—			—			127
Sec. 174 Capitalized R&D		7,914			—			—
Total deferred tax assets		367,201			295,355			83,241
Valuation allowance		(347,789	)		(275,788	)		(62,005	)
Net deferred tax assets		19,412			19,567			21,236
Deferred tax liabilities:
Operating lease right-of-use asset		(17,073	)		(19,217	)		(21,234	)
Capitalized legal fees		—			—			(2	)
Property and equipment		(2,339	)		(350	)		—
Total deferred tax liabilities		(19,412	)		(19,567	)		(21,236	)
Total net deferred tax assets	$	—		$	—		$	—

Schedule of Reconciliation of Effective Tax Rate to Statutory U.S. Federal Rate

A reconciliation of the Company’s effective tax rate to the statutory U.S. federal rate is as follows:


	December 31, 2022			December 31, 2021			December 31, 2020
Federal statutory income tax rate		21.0	%		21.0	%		21.0	%
State taxes		5.8			6.7			4.3
Foreign tax rate differential		(4.7	)		(7.7	)		(7.9	)
Change in valuation allowance		(20.0	)		(78.3	)		(17.3	)
Stock-based compensation		(3.9	)		(1.2	)		6.7
Research tax credit		1.8			2.4			3.8
Sale of future royalties		—			0.1			(9.4	)
Section 162(m)		—			(0.8	)		(1.2	)
Intangible valuation		—			57.8			—
Provision for income taxes		0.0	%		0.0	%		0.0	%

Summary of Unrecognized Tax Benefits Amounts

The beginning and ending unrecognized tax benefits amounts are as follows (in thousands):


	December 31, 2022		December 31, 2021		December 31, 2020
Unrecognized tax benefits at beginning of period	$	6,729	$	4,650	$	1,838
Increases related to current year tax positions		849		2,079		2,812
Unrecognized tax benefits at end of period	$	7,578	$	6,729	$	4,650

Common Stock (Tables)

12 Months Ended

Dec. 31, 2022

Equity [Abstract]

Schedule of Common Stock Reserved for Future Issuances

The Company had reserved common stock for future issuances as follows:


	December 31, 2022		December 31, 2021
Exercise of options outstanding and release of restricted shares		16,822,629		14,887,847
Exercise of common stock warrants outstanding		—		250,000
Issuance of common stock under the 2018 Equity Incentive Plan		1,934,606		2,101,369
Issuance of common stock under the 2018 Employee Share Purchase Plan		425,179		453,042
Total		19,182,414		17,692,258

Stock-Based Compensation (Tables)

12 Months Ended

Dec. 31, 2022

Share-Based Payment Arrangement [Abstract]

Summary of Stock Options Activity Under 2021 LTPIP, 2018 Plan and 2015 Plan

Stock option activity, including stock options and PSOs under the 2021 LTPIP, 2018 Plan and 2015 Plan is summarized as follows:


	Number of Options			Weighted Average Exercise Price		Weighted Average Remaining Contractual Term (in years)		Aggregate Intrinsic Value (in thousands)
Outstanding at December 31, 2021		14,523,917		$	61.68		8.60	$	335,440
Granted		3,079,120		$	8.99
Exercised		(126,999	)	$	13.93
Forfeited or canceled		(933,931	)	$	75.23
Outstanding at December 31, 2022		16,542,107		$	51.48		7.91	$	5,410
Shares exercisable December 31, 2022		8,452,058		$	41.84		7.03	$	5,390
Vested and expected to vest December 31, 2022		16,542,107		$	51.48		7.91	$	5,410

Fair Value of Employee Stock Options Estimated Using Weighted-average Assumptions


	Year Ended December 31,
	2022			2021			2020
Expected volatility		83	%		61	%		66	%
Risk-free interest rate		2.86	%		1.03	%		0.39	%
Dividend yield		0	%		0	%		0	%
Expected term		5.98			6.25			6.00

Fair Value of Non-Employee Awards Estimated Using Weighted-average Assumptions

The fair value of non-employee stock options was estimated using the following weighted-average assumptions:


	Year Ended December 31,
	2021			2020
Expected volatility		60	%		67	%
Risk-free interest rate		0.97	%		0.36	%
Dividend yield		0	%		0	%
Expected term		5.69			5.56

Summary of Restricted Shares

Restricted share activity, including restricted stock units (“RSUs”), and performance-based restricted stock units (“PSUs”), under the 2018 Plan is summarized as follows:


	Number of Restricted Shares			Weighted Average Grant Date Fair Value
Unvested at December 31, 2021		363,930		$	72.75
Granted		67,750			20.71
Vested		(103,032	)		71.06
Canceled		(48,126	)		76.44
Unvested at December 31, 2022		280,522		$	60.17

Summary of Stock-based Compensation Classified in Condensed Consolidated Statements of Operations and Comprehensive Loss

Stock-based compensation is classified in the consolidated statements of operations and comprehensive loss as follows (in thousands):


	Year Ended December 31,
	2022		2021		2020
Research and development	$	59,288	$	33,237	$	16,957
General and administrative		46,745		28,148		13,711
Total stock-based compensation	$	106,033	$	61,385	$	30,668

Net Loss per Share Attributable to Common Stockholders (Tables)

12 Months Ended

Dec. 31, 2022

Earnings Per Share [Abstract]

Computation of Basic and Diluted Net Loss per Share Attributable to Common Stockholders


	Year Ended December 31,
	2022			2021			2020
Numerator:
Net loss attributable to common stockholders	$	(333,823	)	$	(266,990	)	$	(133,096	)
Denominator:
Weighted-average shares outstanding used in computing net loss per share attributable to common stockholders, basic and diluted		52,249,620			51,788,918			45,741,845
Net loss per share attributable to common stockholders, basic and diluted	$	(6.39	)	$	(5.16	)	$	(2.91	)

Summary of Anti-dilutive Securities Excluded from Computation of Diluted Net Loss per Share

The following common share equivalents were excluded from the computation of diluted net loss per common share for the periods presented because their inclusion would have been antidilutive:


	As of December 31,
	2022		2021		2020
Outstanding stock options		16,542,107		14,523,917		6,897,276
Unvested restricted shares		280,522		363,930		359,945
Total		16,822,629		14,887,847		7,257,221

The Company - Additional Information (Details) $ in Millions	Dec. 31, 2022 USD ($)
Organization Consolidation And Presentation Of Financial Statements [Line Items]
Cash, cash equivalents and marketable securities	$ 478.9

Summary of Significant Accounting Policies - Schedule of Property Plant and Equipment Estimated Useful Lives (Details)	12 Months Ended
	Dec. 31, 2022
Furniture and Fixtures
Summary of Significant Accounting Policies [Line Items]
Property and equipment estimated useful lives of assets	5 years
Machinery and Equipment \| Maximum
Summary of Significant Accounting Policies [Line Items]
Property and equipment estimated useful lives of assets	10 years
Machinery and Equipment \| Minimum
Summary of Significant Accounting Policies [Line Items]
Property and equipment estimated useful lives of assets	3 years
Computer Software and Hardware \| Maximum
Summary of Significant Accounting Policies [Line Items]
Property and equipment estimated useful lives of assets	5 years
Computer Software and Hardware \| Minimum
Summary of Significant Accounting Policies [Line Items]
Property and equipment estimated useful lives of assets	3 years
Leasehold Improvement
Summary of Significant Accounting Policies [Line Items]
Property plant and equipment, estimated useful lives, description	Lesser of the useful life or the term of the respective lease

Summary of Significant Accounting Policies - Additional Information (Details) $ in Thousands		12 Months Ended
	Dec. 01, 2019 USD ($)	Dec. 31, 2022 USD ($) Segment	Dec. 31, 2021 USD ($)	Dec. 31, 2020 USD ($)	Jul. 31, 2021 USD ($)	Feb. 29, 2020 USD ($)
Summary of Significant Accounting Policies [Line Items]
Foreign currency transaction loss		$ (300)	$ (300)	$ (300)
Number of reportable segments \| Segment		1
Number of operating segments \| Segment		1
Long-term restricted cash		$ 6,324	6,324	6,324
Loss on disposal of long-lived asset		0	0
Unrecognized tax benefits, interest and penalties charged		0	0	$ 0
Operating lease right-of-use asset		59,369	66,744
Operating Lease, Liability		87,733
Allowance for credit losses for available-for-sale debt securities		0
Baker Bros. Advisors LP \| Funding Agreement
Summary of Significant Accounting Policies [Line Items]
Capped percentage of royalty on future net sales	4.50%
Contractual obligation under funding agreement	$ 225,000
Funds Payable Upon Enrollment Of Patients		$ 0			$ 125,000	$ 125,000
Furniture and Fixtures
Summary of Significant Accounting Policies [Line Items]
Property and equipment estimated useful lives of assets		5 years
Leasehold Improvement
Summary of Significant Accounting Policies [Line Items]
Property plant and equipment, estimated useful lives, description		Lesser of the useful life or the term of the respective lease
Deposited with Financial Institution
Summary of Significant Accounting Policies [Line Items]
Long-term restricted cash		$ 6,300	$ 6,300
Maximum \| Machinery and Equipment
Summary of Significant Accounting Policies [Line Items]
Property and equipment estimated useful lives of assets		10 years
Minimum \| Baker Bros. Advisors LP \| Funding Agreement
Summary of Significant Accounting Policies [Line Items]
Ownership percentage threshold	5.00%
Minimum \| Machinery and Equipment
Summary of Significant Accounting Policies [Line Items]
Property and equipment estimated useful lives of assets		3 years

Property and Equipment, Net - Summary of Property and Equipment, Net (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Property Plant and Equipment [Line Items]
Total property and equipment	$ 63,108	$ 44,269
Less: Accumulated depreciation	(6,724)	(2,939)
Property and equipment, net	56,384	41,330
Leasehold Improvement
Property Plant and Equipment [Line Items]
Total property and equipment	43,483	1,285
Manufacturing Equipment
Property Plant and Equipment [Line Items]
Total property and equipment	12,763	4,672
Furniture and Fixtures
Property Plant and Equipment [Line Items]
Total property and equipment	1,969	214
Computer Software
Property Plant and Equipment [Line Items]
Total property and equipment	374	289
Construction in Progress
Property Plant and Equipment [Line Items]
Total property and equipment	$ 4,519	$ 37,809

Property and Equipment, Net - Additional Information (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Property, Plant and Equipment [Abstract]
Depreciation	$ 3,796	$ 1,003	$ 477

Accrued Liabilities and Other Current Liabilities - Schedule of Accrued Liabilities and Other Current Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Accounts Payable and Accrued Liabilities, Current [Abstract]
Accrued clinical trial and related costs	$ 18,334	$ 21,776
Accrued salaries and benefits	6,033	6,187
Accrued manufacturing and research & development costs	5,978	6,041
Accrued leasehold improvements	1,893	13,021
Accrued legal fees	245	403
Accrued professional fees	39	176
Accrued other liabilities	919	715
Total accrued and other current liabilities	$ 33,440	$ 48,319

Fair Value Measurements - Summary of Fair Value Hierarchy for Assets and Liabilities Measured at Fair Value on Recurring Basis (Details) - Fair Value, Measurements, Recurring - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total	$ 462,117	$ 706,703
Money Market Funds
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Cash equivalents	173,617	706,703
U.S. Treasury Securities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Marketable securities	288,500
Quoted Price in Active Markets (Level 1)
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total	173,617	706,703
Quoted Price in Active Markets (Level 1) \| Money Market Funds
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Cash equivalents	173,617	706,703
Quoted Price in Active Markets (Level 1) \| U.S. Treasury Securities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Marketable securities	0
Significant Observable Inputs (Level 2)
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total	288,500	0
Significant Observable Inputs (Level 2) \| Money Market Funds
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Cash equivalents	0	0
Significant Observable Inputs (Level 2) \| U.S. Treasury Securities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Marketable securities	288,500
Significant Unobservable Inputs (Level 3)
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total	0	0
Significant Unobservable Inputs (Level 3) \| Money Market Funds
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Cash equivalents	0	$ 0
Significant Unobservable Inputs (Level 3) \| U.S. Treasury Securities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Marketable securities	$ 0

Fair Value Measurements - Additional Information (Details) - USD ($)	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Transfers of assets or liabilities between the fair value measurement levels	$ 0	$ 0

Marketable Securities - Summary of Marketable Securities Held (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2022 USD ($)
Marketable Securities [Line Items]
Amortized Cost, current	$ 289,807
Unrealized Gains, Current	0
Unrealized Losses, Current	(1,307)
Fair Value, current	288,500
U.S. Treasury Securities
Marketable Securities [Line Items]
Amortized Cost, current	289,807
Unrealized Gains, Current	0
Unrealized Losses, Current	(1,307)
Fair Value, current	$ 288,500

Marketable Securities - Additional Information (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2022 USD ($)
Marketable Securities [Line Items]
Allowance for credit losses for available-for-sale debt securities	$ 0
Marketable securities, contractual maturities	1 year
Realized gains or losses recognized on sale or maturity of available-for-sale debt securities	$ 0
Impairment charges or recoveries related to marketable securities	$ 0

Commitments and Contingencies - Additional Information (Details) $ in Thousands, ft² in Millions	1 Months Ended				12 Months Ended
	Aug. 31, 2020	Jun. 30, 2020 USD ($) ft² Building	Apr. 30, 2020 CHF (SFr) m²	Mar. 31, 2016 USD ($)	Dec. 31, 2022 USD ($)	Dec. 31, 2021 USD ($)	Dec. 31, 2020 USD ($)	Apr. 30, 2021 CHF (SFr)	Jul. 01, 2020 USD ($)
Commitments And Contingencies Disclosure [Line Items]
Operating lease right-of-use asset					$ 59,369	$ 66,744
Lease liabilities					87,733
Current portion of tenant improvement allowance payable					33,440	48,319
Other liabilities, non-current portion of tenant Improvement allowance payable					162	211
Tenant Improvement Allowance Payable
Commitments And Contingencies Disclosure [Line Items]
Other liabilities, non-current portion of tenant Improvement allowance payable					200	200
Lonza \| Service Agreements
Commitments And Contingencies Disclosure [Line Items]
Cancelable and/ or non-cancelable contractual obligations, total					56,800	69,500
Unrecorded unconditional purchase obligation, expenses recognized					47,400	31,800	$ 16,800
Unrecorded unconditional purchase obligation, cancellation fees					0
Manufacturing Agreement
Commitments And Contingencies Disclosure [Line Items]
Manufacturing Agreement Expense					44,100
Manufacturing Agreement \| Other Assets [Member]
Commitments And Contingencies Disclosure [Line Items]
Manufacturing Agreement Expense					40,000
Maximum \| Tenant Improvement Allowance Payable
Commitments And Contingencies Disclosure [Line Items]
Current portion of tenant improvement allowance payable					100	100
Minimum \| Lease Agreements [Member]
Commitments And Contingencies Disclosure [Line Items]
Operating lease right-of-use asset					12,800	$ 12,800	$ 6,100
Clinical and Commercial Supply of Drug Substance \| Lonza
Commitments And Contingencies Disclosure [Line Items]
Manufacturing agreement initial term	8 years
Clinical and Commercial Supply of Drug Substance \| Manufacturing Agreement \| Lonza
Commitments And Contingencies Disclosure [Line Items]
Estimated capital contribution \| SFr								SFr 75,000,000.0
Annual Suite Fees Payment					150,000
Clinical and Commercial Supply of Drug Substance \| Maximum \| Manufacturing Agreement \| Lonza
Commitments And Contingencies Disclosure [Line Items]
Manufacturing agreement term that can be extended	16 years
Leasehold Improvements \| California
Commitments And Contingencies Disclosure [Line Items]
Debt instrument term				10 years
Lease Agreement on June 2020 \| California
Commitments And Contingencies Disclosure [Line Items]
Number of buildings leased \| Building		2
Initial lease term		6 years 6 months
Monthly rent expense		$ 600
Annual rent year-over-year increase percentage		3.00%
Cash-collateralized letter of credit		$ 10,900							$ 6,200
Lease Agreement on June 2020 \| California \| Maximum
Commitments And Contingencies Disclosure [Line Items]
Lease area \| ft²		82,662
Lease Agreement on June 2020 \| California \| Minimum
Commitments And Contingencies Disclosure [Line Items]
Lease area \| ft²		72,812
Lease Agreement on June 2020 \| 1200 Page Mill Road in Palo Alto \| California
Commitments And Contingencies Disclosure [Line Items]
Total rent abatement		$ 7,200
Lessee operating lease option to extend		6.5 years
Tenant improvement allowance		$ 1,200
Lease Agreement on June 2020 \| 1250 Page Mill Road in Palo Alto \| California
Commitments And Contingencies Disclosure [Line Items]
Initial lease term		13 years
Monthly rent expense		$ 500
Annual rent year-over-year increase percentage		3.00%
Total rent abatement		$ 6,300
Lessee operating lease option to extend		5 years
Tenant improvement allowance		$ 10,600
Number of options to extend lease term		2
Lease Agreement on April 2020 \| Rottenstrasse 5 in Visp \| Switzerland
Commitments And Contingencies Disclosure [Line Items]
Lease area \| m²			1,000
Initial lease term			5 years
Monthly rent expense \| SFr			SFr 32,000.0
Automatic renewal interval			5 years
Lease Agreement on April 2020 \| Rottenstrasse 5 in Visp \| Switzerland \| Maximum
Commitments And Contingencies Disclosure [Line Items]
Lessee, operating lease, term of contract			15 years
Tenant Improvement Allowance Agreement \| Leasehold Improvements
Commitments And Contingencies Disclosure [Line Items]
Tenant improvement allowance					$ 10,200
Tenant Improvement Allowance Agreement \| Leasehold Improvements \| California
Commitments And Contingencies Disclosure [Line Items]
Improvements allowance payable to be drawn				$ 400
Interest rate				8.00%
Lease term				Oct. 31, 2023

Commitments and Contingencies - Summary of Maturities of Operating Lease Liabilities (Details) $ in Thousands	Dec. 31, 2022 USD ($)
Operating Lease
2023	$ 15,592
2024	15,020
2025	15,458
2026	15,909
2027	9,183
Thereafter	46,184
Total undiscounted lease payments	117,346
Less: imputed interest	(28,055)
Less: future tenant improvement reimbursements	(1,558)
Total operating lease liabilities	$ 87,733

Commitments and Contingencies - Summary of Lessee, Weighted Average Remaining Lease Term and Weighted Average Discount Rates (Details)	Dec. 31, 2022	Dec. 31, 2021
Commitments and Contingencies Disclosure [Abstract]
Weighted-average remaining lease term (in years)	8 years 4 months 24 days	8 years 9 months 18 days
Weighted-average discount rate	6.80%	6.70%

Income Taxes - Additional Information (Details) - USD ($)	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Income Taxes [Line Items]
Increase in valuation allowance	$ (72,000,000.0)	$ 213,800,000	$ 24,800,000
Research and development credit carryforwards	25,110,000	18,330,000	10,527,000
Unrecognized tax benefits	0	0	0
Interest charged	0
Penalties charged	$ 0
CARES Act Member
Income Taxes [Line Items]
Description of corporate income tax provisions	The CARES Act contains several corporate income tax provisions, including making remaining alternative minimum tax credits immediately refundable; providing a 5-year carryback of NOLs generated in tax years 2018, 2019, and 2020, and removing the 80% taxable income limitation on utilization of those NOLs if carried back to prior tax years or utilized in tax years beginning before 2021; temporarily liberalizing the interest deductibility rules under Section 163(j) of the CARES Act, by raising the adjusted taxable income limitation from 30% to 50% for tax years 2019 and 2020 and giving taxpayers the election of using 2019 adjusted taxable income for purposes of computing 2020 interest deductibility
Federal
Income Taxes [Line Items]
Net operating loss
Net operating loss carryforwards expiration start year	2035
Research and development credit carryforwards
Tax credit carryforwards expiration start year	2035
Number of periods open for examination	3 years
Federal \| Net Operating Loss Not Subject to Expiration
Income Taxes [Line Items]
Net operating loss
State
Income Taxes [Line Items]
Net operating loss
Net operating loss carryforwards expiration start year	2035
Number of periods open for examination	4 years
California
Income Taxes [Line Items]
Net operating loss deductions	$ 1,000,000
California \| Maximum
Income Taxes [Line Items]
Offset tax credit		$ 5,000,000	$ 5,000,000

Income Taxes - Components of Loss before Income Taxes (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Income Tax Disclosure [Abstract]
United States	$ (163,240)	$ (46,590)	$ (17,273)
Foreign	(170,550)	(220,326)	(115,809)
Total loss before income taxes	$ 333,790	$ (266,916)	$ (133,082)

- Definition

Amount of income (loss) from continuing operations, including income (loss) from equity method investments, before deduction of income tax expense (benefit), and income (loss) attributable to noncontrolling interest.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
-SubTopic 10
-Section 50
-Paragraph 32
-Subparagraph (c)
-URI https://asc.fasb.org/extlink&oid=126901519&loc=d3e8933-108599

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
-SubTopic 10
-Section 50
-Paragraph 30
-Subparagraph (b)
-URI https://asc.fasb.org/extlink&oid=126901519&loc=d3e8906-108599

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
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+ Details

Income Taxes - Schedule of Provision (Benefit) for Income Taxes (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Current:
Federal	$ 0	$ 0	$ 0
State	0	0	0
Foreign	33	74	14
Total current	33	74	14
Deferred:
Federal	0	0	0
State	0	0	0
Foreign	0	0	0
Total deferred	0	0	0
Provision (Benefit) for income taxes	$ 33	$ 74	$ 14

Income Taxes - Components of Deferred Tax Assets (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Deferred tax assets:
Net operating loss carryforwards	$ 117,232	$ 75,259	$ 28,451
Intangible assets	166,259	166,269	12,088
Research and development tax credits	25,110	18,330	10,527
Stock-based compensation	23,576	10,823	8,405
Accruals	1,562	1,532	1,367
Operating lease liability	25,548	23,142	22,276
Property and equipment	0	0	127
Sec. 174 Capitalized R&D	7,914
Total deferred tax assets	367,201	295,355	83,241
Valuation allowance	(347,789)	(275,788)	(62,005)
Net deferred tax assets	19,412	19,567	21,236
Deferred tax liabilities:
Operating lease right-of-use asset	(17,073)	(19,217)	(21,234)
Capitalized legal fees	0	0	(2)
Property and equipment	(2,339)	(350)
Total deferred tax liabilities	(19,412)	(19,567)	(21,236)
Total net deferred tax assets	$ 0	$ 0	$ 0

Income Taxes - Schedule of Reconciliation of Effective Tax Rate to Statutory U.S. Federal Rate (Details)	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Income Tax Disclosure [Abstract]
Federal statutory income tax rate	21.00%	21.00%	21.00%
State taxes	5.80%	6.70%	4.30%
Foreign tax rate differential	(4.70%)	(7.70%)	(7.90%)
Change in valuation allowance	(20.00%)	(78.30%)	(17.30%)
Stock-based compensation	(3.90%)	(1.20%)	6.70%
Research tax credit	1.80%	2.40%	3.80%
Sale of future royalties		0.10%	(9.40%)
Section 162(m)		(0.80%)	(1.20%)
Intangible Valuation		57.80%	0.00%
Provision for income taxes	0.00%	0.00%	0.00%

Income Taxes - Summary of Unrecognized Tax Benefits Amounts (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Income Tax Disclosure [Abstract]
Unrecognized tax benefits at beginning of period	$ 6,729	$ 4,650	$ 1,838
Increases related to current year tax positions	849	2,079	2,812
Unrecognized tax benefits at end of period	$ 7,578	$ 6,729	$ 4,650

Preferred Stock - Additional Information (Details) - $ / shares	Dec. 31, 2022	Dec. 31, 2021
Class Of Stock [Line Items]
Preferred stock, shares authorized	10,000,000	10,000,000
Preferred stock, par value	$ 0.0001	$ 0.0001
Preferred Stock, Shares Issued	0	0
Preferred Stock, Shares Outstanding	0	0
Maximum
Class Of Stock [Line Items]
Preferred stock, shares authorized	10,000,000	10,000,000

Common Stock - Additional Information (Details)	12 Months Ended
Common Stock - Additional Information (Details)	Dec. 31, 2022 Vote $ / shares shares	Dec. 31, 2021 Vote $ / shares shares
Equity [Abstract]
Common stock, shares authorized \| shares	490,000,000	490,000,000
Common stock, par value \| $ / shares	$ 0.0001	$ 0.0001
Common stock, number of vote per share \| Vote	1	1

Common Stock - Schedule of Common Stock Reserved for Future Issuances (Details) - shares	Dec. 31, 2022	Dec. 31, 2021
Class Of Stock [Line Items]
Common stock reserved for future issuances	19,182,414	17,692,258
Stock Options Outstanding and Release of Restricted Shares
Class Of Stock [Line Items]
Common stock reserved for future issuances	16,822,629	14,887,847
2018 Equity Incentive Plan
Class Of Stock [Line Items]
Common stock reserved for future issuances	1,934,606	2,101,369
2018 Employee Share Purchase Plan
Class Of Stock [Line Items]
Common stock reserved for future issuances	425,179	453,042
Warrant
Class Of Stock [Line Items]
Common stock reserved for future issuances	0	250,000

Stock-Based Compensation - Additional Information (Details) - USD ($) $ / shares in Units, $ in Thousands	1 Months Ended			12 Months Ended
	Aug. 31, 2021	Feb. 28, 2021	Dec. 31, 2019	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock-based compensation expense recognized				$ 106,033	$ 61,385	$ 30,668
Unrecognized stock-based compensation expense					$ 311,300
Unrecognized stock-based compensation weighted-average period expected for recognition					3 years 7 months 9 days
Stock options, vested				80,456
Common stock, shares reserved for issuance				19,182,414	17,692,258
Employee Stock Options
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock-based compensation expense recognized				$ 93,800	$ 44,100	$ 20,800
Stock options, weighted-average grant date fair value				$ 6.31	$ 51.55	$ 32.44
Total fair value of employee options vested				$ 28,900	$ 26,900	$ 19,700
Operational Milestone Earning Percentage/Dividend yield				0.00%	0.00%	0.00%
Stock options, granted				3,079,120
Risk-free interest rate				2.86%	1.03%	0.39%
Expected volatility				83.00%	61.00%	66.00%
Expected term				5 years 11 months 23 days	6 years 3 months	6 years
total intrinsic value of stock options exercised				$ 6,100	$ 40,200	$ 58,100
Non-employee Stock Options
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Operational Milestone Earning Percentage/Dividend yield					0.00%	0.00%
Risk-free interest rate					0.97%	0.36%
Expected volatility					60.00%	67.00%
Expected term					5 years 8 months 8 days	5 years 6 months 21 days
Options Granted to Non-employees
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock-based compensation expense recognized				$ 1,200	$ 1,200	$ 700
Restricted Stock Awards (RSAs)
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock units, granted				67,750
Restricted Stock Units (RSUs)
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock-based compensation expense recognized				$ 4,600	4,400	1,900
Stock units, granted				67,750
Total fair value of employee options vested				$ 4,900	3,200	300
Performance Based Equity Awards
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock-based compensation expense recognized				$ 6,300	11,400	$ 7,200
Operational Milestone Earning Percentage/Dividend yield		25.00%	25.00%	0.00%
Risk-free interest rate				1.05%
Expected volatility				60.00%
Expected term				6 years 5 months 26 days
Performance-based Stock Options
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock-based compensation expense recognized				$ 0
Total fair value of employee options vested				$ 6,200
Stock options, vested				42,536
Stock options, granted	478,750	190,831	170,150
Performance Based Restricted Stock Units
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock units, granted			128,900
Total fair value of employee options vested				$ 3,900
Stock options, vested				25,907
2019 PSA
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Operational Milestone Earning Percentage/Dividend yield				0.00%
Risk-free interest rate				1.67%
Expected volatility				72.00%
Expected term				6 years 3 months 21 days
2021 PSO
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Operational Milestone Earning Percentage/Dividend yield				0.00%
Risk-free interest rate				0.66%
Expected volatility				66.00%
Expected term				5 years 11 months 8 days
Non-Employee Awards
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock options, granted				0
2018 Equity Incentive Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Awards vesting period				4 years
Number of shares increases annually				2,073,050
Number of shares available for grant				1,934,606
2018 Equity Incentive Plan \| Minimum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Percentage of outstanding stock				4.00%
2018 Equity Incentive Plan \| Incentive Stock Options
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Common stock, shares reserved for issuance				4,300,000
2018 Equity Incentive Plan \| Incentive Stock Options \| Maximum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Options, periods granted				10 years
2018 Equity Incentive Plan \| ISO Granted to a Greater than 10% Stockholder \| Maximum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Options, periods granted				5 years
Options exercise price, percentage of estimated fair value of shares on grant date				110.00%
2018 Employee Share Purchase Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock-based compensation expense recognized				$ 200	300
Common stock, shares reserved for issuance				460,000
Issuance of common stock pursuant to employee stock purchase plans, shares				27,863
Common stock at price per share				85.00%
2021 LTPIP
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Unrecognized stock-based compensation expense				$ 247,900
Stock units, granted				6,818,584
Unrecognized stock-based compensation weighted-average period expected for recognition				4 years 7 days
2021 LTPIP \| Employee Stock Options
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock-based compensation expense recognized				$ 65,100	$ 15,700

Stock-Based Compensation - Summary of Stock Options Activity Under 2021 LTPIP, 2018 Plan and 2015 Plan (Details) - 2021 LTPIP, 2018 Plan and 2015 Plan - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Number of Options
Beginning balance	14,523,917
Granted	3,079,120
Exercised	(126,999)
Forfeited or canceled	(933,931)
Ending balance	16,542,107	14,523,917
Shares exercisable	8,452,058
Vested and expected to vest	16,542,107
Weighted Average Exercise Price
Beginning balance	$ 61.68
Granted	8.99
Exercised	13.93
Forfeited or canceled	75.23
Ending balance	51.48	$ 61.68
Shares exercisable	41.84
Vested and expected to vest	$ 51.48
Weighted Average Remaining Contractual Term (in years)
Weighted Average Remaining Contractual Term (in years)	7 years 10 months 28 days	8 years 7 months 6 days
Shares exercisable	7 years 10 days
Vested and expected to vest	7 years 10 months 28 days
Aggregate Intrinsic Value
Balance	$ 5,410	$ 335,440
Shares exercisable	5,390
Vested and expected to vest	$ 5,410

Stock-Based Compensation - Fair Value of Employee Stock Options Estimated Using Weighted-average Assumptions (Details) - Employee Stock Options	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Expected volatility	83.00%	61.00%	66.00%
Risk-free interest rate	2.86%	1.03%	0.39%
Operational Milestone Earning Percentage/Dividend yield	0.00%	0.00%	0.00%
Expected term	5 years 11 months 23 days	6 years 3 months	6 years

Stock-Based Compensation - Summary of Restricted Shares (Details) - Restricted Stock Awards (RSAs)	12 Months Ended
	Dec. 31, 2022 $ / shares shares
Number of Restricted Shares
Unvested, beginning balance \| shares	363,930
Granted \| shares	67,750
Vested \| shares	(103,032)
Canceled \| shares	(48,126)
Unvested, ending balance \| shares	280,522
Weighted Average Grant Date Fair Value
Unvested, beginning balance \| $ / shares	$ 72.75
Granted \| $ / shares	20.71
Vested \| $ / shares	71.06
Canceled \| $ / shares	76.44
Unvested, ending balance \| $ / shares	$ 60.17

Stock-Based Compensation - Fair Value of Non-employee Awards Estimated Using Weighted-average Assumptions (Details) - Non-employee Stock Options	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Expected volatility	60.00%	67.00%
Risk-free interest rate	0.97%	0.36%
Operational Milestone Earning Percentage/Dividend yield	0.00%	0.00%
Expected term	5 years 8 months 8 days	5 years 6 months 21 days

Stock-Based Compensation - Summary of Stock-based Compensation Classified in Condensed Consolidated Statements of Operations and Comprehensive Loss (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Total stock-based compensation	$ 106,033	$ 61,385	$ 30,668
Research and Development
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Total stock-based compensation	59,288	33,237	16,957
General and Administrative
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Total stock-based compensation	$ 46,745	$ 28,148	$ 13,711

Net Loss per Share Attributable to Common Stockholders - Computation of Basic and Diluted Net Loss per Share Attributable to Common Stockholders (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Numerator:
Net loss	$ (333,823)	$ (266,990)	$ (133,096)
Denominator:
Weighted-average shares outstanding used in computing net loss per share attributable to common stockholders, basic	52,249,620	51,788,918	45,741,845
Weighted-average shares outstanding used in computing net loss per share attributable to common stockholders, diluted	52,249,620	51,788,918	45,741,845
Net loss per share attributable to common stockholders basic	$ (6.39)	$ (5.16)	$ (2.91)
Net loss per share attributed to common stockholders diluted	$ (6.39)	$ (5.16)	$ (2.91)

- Definition

The amount of net income (loss) for the period per each share of common stock or unit outstanding during the reporting period.

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- Definition

The amount of net income (loss) for the period available to each share of common stock or common unit outstanding during the reporting period and to each share or unit that would have been outstanding assuming the issuance of common shares or units for all dilutive potential common shares or units outstanding during the reporting period.

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+ Details

- Definition

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

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+ Details

Net Loss per Share Attributable to Common Stockholders - Summary of Anti-dilutive Securities Excluded from Computation of Diluted Net Loss per Share (Details) - shares	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Anti-dilutive securities excluded from the computation of diluted net loss per share	16,822,629	14,887,847	7,257,221
Outstanding stock options
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Anti-dilutive securities excluded from the computation of diluted net loss per share	16,542,107	14,523,917	6,897,276
Unvested Restricted Shares
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Anti-dilutive securities excluded from the computation of diluted net loss per share	280,522	363,930	359,945

401(k) Plan - Additional Information (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Defined Contribution Plan Disclosure [Line Items]
Plan name	401(k)
Defined Contribution Plan, Plan Name [Extensible List]	Retirement and Savings Plan [Member]
Employer matching contribution, percent of match	100.00%
Expense related to matching contributions	$ 0.9	$ 0.7	$ 0.6
IRS
Defined Contribution Plan Disclosure [Line Items]
Defined contribution plan, employer matching contribution cap on employee contribution limit	50.00%

Liability Related to Sale of Future Royalties - Additional Information (Details) - USD ($) $ in Thousands			12 Months Ended
	Feb. 04, 2020	Dec. 01, 2019	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020	Jul. 31, 2021	Feb. 29, 2020
Related Party Transaction [Line Items]
Proceeds from sale of future royalties			$ 0	$ 0	$ 99,643
Liability related to sale of future royalties			99,996	99,943
Interest expense, liability related to sale of future royalties			0	$ 0
Funding Agreement
Related Party Transaction [Line Items]
Remaining Funding amount			125,000
Baker Bros. Advisors LP \| Funding Agreement
Related Party Transaction [Line Items]
Capped percentage of royalty on future net sales		4.50%
Contractual obligation under funding agreement		$ 225,000
Percentage of repurchase of royalties		100.00%
Proceeds from sale of future royalties	$ 100,000
Funds to be payable upon enrollment of patients			0			$ 125,000	$ 125,000
Percentage of repurchase of royalties							50.00%
Liability related to sale of future royalties			$ 100,000
Baker Bros. Advisors LP \| Funding Agreement \| Minimum
Related Party Transaction [Line Items]
Ownership percentage		5.00%

Selected Quarterly Financial Data - Schedule of Quarterly Financial Information (Unaudited) (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Quarterly Financial Information Disclosure [Abstract]
Loss from operations	$ (341,379)	$ (267,051)	$ (136,007)
Net loss	$ (333,823)	$ (266,990)	$ (133,096)
Net loss per share attributable to common stockholders basic	$ (6.39)	$ (5.16)	$ (2.91)
Net loss per share attributed to common stockholders diluted	$ (6.39)	$ (5.16)	$ (2.91)

- Definition

The amount of net income (loss) for the period per each share of common stock or unit outstanding during the reporting period.

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

+ References

+ Details