Cover
Cover - USD ($) $ in Millions | 12 Months Ended | ||
Dec. 31, 2023 | Mar. 07, 2024 | Jun. 30, 2023 | |
Cover [Abstract] | |||
Document Type | 10-K | ||
Document Annual Report | true | ||
Document Period End Date | Dec. 31, 2023 | ||
Current Fiscal Year End Date | --12-31 | ||
Document Transition Report | false | ||
Entity File Number | 001-37449 | ||
Entity Registrant Name | ALPINE IMMUNE SCIENCES, INC. | ||
Entity Incorporation, Date of Incorporation | DE | ||
Entity Tax Identification Number | 20-8969493 | ||
Entity Address, Address Line One | 188 East Blaine Street | ||
Entity Address, Address Line Two | Suite 200 | ||
Entity Address, City or Town | Seattle, | ||
Entity Address, State or Province | WA | ||
Entity Address, Postal Zip Code | 98102 | ||
City Area Code | 206 | ||
Local Phone Number | 788-4545 | ||
Title of 12(b) Security | Common Stock, par value $0.001 per share | ||
Trading Symbol | ALPN | ||
Security Exchange Name | NASDAQ | ||
Entity Well-known Seasoned Issuer | Yes | ||
Entity Voluntary Filers | No | ||
Entity Current Reporting Status | Yes | ||
Entity Interactive Data Current | Yes | ||
Entity Filer Category | Non-accelerated Filer | ||
Entity Small Business | true | ||
Entity Emerging Growth Company | false | ||
ICFR Auditor Attestation Flag | false | ||
Document Financial Statement Error Correction | false | ||
Entity Shell Company | false | ||
Entity Public Float | $ 349.1 | ||
Entity Common Stock, Shares Outstanding | 65,546,136 | ||
Documents Incorporated by Reference | Portions of the Registrant’s Definitive Proxy Statement relating to the 2024 Annual Meeting of Stockholders, which will be filed with the Securities and Exchange Commission subsequent to the date hereof, are incorporated by reference into Part III of this Report. Such Proxy Statement will be filed with the Securities and Exchange Commission not later than 120 days following the end of the Registrant’s fiscal year ended December 31, 2023. | ||
Entity Central Index Key | 0001626199 | ||
Document Fiscal Year Focus | 2023 | ||
Document Fiscal Period Focus | FY | ||
Amendment Flag | false |
Audit Information
Audit Information | 12 Months Ended |
Dec. 31, 2023 | |
Audit Information [Abstract] | |
Auditor Name | Ernst & Young LLP |
Auditor Location | Seattle, Washington |
Auditor Firm ID | 42 |
CONSOLIDATED BALANCE SHEETS
CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands | Dec. 31, 2023 | Dec. 31, 2022 |
Current assets: | ||
Cash and cash equivalents | $ 43,921 | $ 13,376 |
Short-term investments | 283,491 | 224,265 |
Accounts receivable | 167 | 392 |
Prepaid expenses and other current assets | 2,455 | 2,960 |
Total current assets | 330,034 | 240,993 |
Restricted cash, noncurrent | 268 | 254 |
Property and equipment, net | 1,484 | 1,584 |
Operating lease, right-of-use asset | 7,510 | 8,219 |
Long-term investments | 40,556 | 35,481 |
Deferred tax asset | 0 | 155 |
Total assets | 379,852 | 286,686 |
Current liabilities: | ||
Accounts payable | 3,593 | 4,286 |
Accrued liabilities | 21,187 | 14,003 |
Deferred revenue, current | 16,288 | 35,571 |
Operating lease liability, current | 912 | 756 |
Current portion of long-term debt | 0 | 3,380 |
Total current liabilities | 41,980 | 57,996 |
Deferred revenue, noncurrent | 929 | 39,185 |
Operating lease liability, noncurrent | 9,002 | 10,085 |
Total liabilities | 51,911 | 107,266 |
Commitments and contingencies | ||
Stockholders’ equity: | ||
Preferred stock, $0.001 par value per share; 10,000,000 shares authorized at December 31, 2023 and 2022; zero shares issued and outstanding at December 31, 2023 and 2022 | 0 | 0 |
Common stock, $0.001 par value per share; 200,000,000 shares authorized at December 31, 2023 and 2022; 60,347,457 shares issued and outstanding at December 31, 2023; 47,234,900 shares issued and 45,984,433 shares outstanding at December 31, 2022 | 60 | 46 |
Treasury stock, at cost; zero and 1,250,467 shares at December 31, 2023 and 2022, respectively | 0 | 0 |
Additional paid-in capital | 583,629 | 404,456 |
Accumulated other comprehensive gain (loss) | 397 | (1,121) |
Accumulated deficit | (256,145) | (223,961) |
Total stockholders’ equity | 327,941 | 179,420 |
Total liabilities and stockholders’ equity | $ 379,852 | $ 286,686 |
CONSOLIDATED BALANCE SHEETS (Pa
CONSOLIDATED BALANCE SHEETS (Parenthetical) - $ / shares | Dec. 31, 2023 | Dec. 31, 2022 |
Statement of Financial Position [Abstract] | ||
Preferred stock, par value (in dollars per share) | $ 0.001 | $ 0.001 |
Preferred stock, shares authorized (in shares) | 10,000,000 | 10,000,000 |
Preferred stock, shares outstanding (in shares) | 0 | 0 |
Preferred stock, shares issued (in shares) | 0 | 0 |
Common stock, par value (in dollars per share) | $ 0.001 | $ 0.001 |
Common stock, shares authorized (in shares) | 200,000,000 | 200,000,000 |
Common stock, shares issued (in shares) | 60,347,457 | 47,234,900 |
Common stock, shares outstanding (in shares) | 60,347,457 | 45,984,433 |
Treasury stock, shares (in shares) | 0 | 1,250,467 |
CONSOLIDATED STATEMENTS OF OPER
CONSOLIDATED STATEMENTS OF OPERATIONS AND COMPREHENSIVE INCOME (LOSS) - USD ($) $ in Thousands | 12 Months Ended | ||
Dec. 31, 2023 | Dec. 31, 2022 | Dec. 31, 2021 | |
Income Statement [Abstract] | |||
Revenue from Contract with Customer, Product and Service [Extensible Enumeration] | Collaboration [Member] | Collaboration [Member] | Collaboration [Member] |
Collaboration revenue | $ 58,876 | $ 30,064 | $ 23,443 |
Operating expenses: | |||
Research and development | 80,904 | 70,243 | 58,742 |
General and administrative | 22,222 | 17,968 | 14,560 |
Total operating expenses | 103,126 | 88,211 | 73,302 |
Loss from operations | (44,250) | (58,147) | (49,859) |
Other income (expense): | |||
Interest income | 11,852 | 3,288 | 259 |
Interest expense | (98) | (476) | (816) |
Other, net | 415 | (97) | (4) |
Loss before taxes | (32,081) | (55,432) | (50,420) |
Income tax (expense) benefit | (103) | (2,330) | 87 |
Net loss | (32,184) | (57,762) | (50,333) |
Comprehensive income (loss): | |||
Unrealized gain (loss) on investments | 1,493 | (901) | (238) |
Unrealized gain (loss) on foreign currency translation | 25 | 53 | (88) |
Comprehensive loss | $ (30,666) | $ (58,610) | $ (50,659) |
Weighted-average shares used to compute basic net loss per share (in shares) | 50,000,339 | 33,435,280 | 25,476,889 |
Weighted-average shares used to compute diluted net loss per share (in shares) | 50,000,339 | 33,435,280 | 25,476,889 |
Basic net loss per share (in dollars per share) | $ (0.64) | $ (1.73) | $ (1.98) |
Diluted net loss per share (in dollars per share) | $ (0.64) | $ (1.73) | $ (1.98) |
CONSOLIDATED STATEMENT OF STOCK
CONSOLIDATED STATEMENT OF STOCKHOLDERS’ EQUITY - USD ($) $ in Thousands | Total | Common Stock | Treasury | Additional Paid-in Capital | Accumulated Other Comprehensive Gain (Loss) | Accumulated Deficit |
Balance at beginning of period (in shares) at Dec. 31, 2020 | 23,803,183 | |||||
Balance at beginning of period (in shares) at Dec. 31, 2020 | 50,467 | |||||
Balance at beginning of period at Dec. 31, 2020 | $ 62,158 | $ 24 | $ 177,947 | $ 53 | $ (115,866) | |
Increase (Decrease) in Stockholders' Equity [Roll Forward] | ||||||
Issuance of common stock in Private Placement/public, net of offering costs (in shares) | 6,489,357 | |||||
Issuance of common stock in Private Placement/public, net of offering costs | 90,733 | $ 6 | 90,727 | |||
Issuance of common stock to Amgen (in shares) | 951,980 | |||||
Issuance of common stock to Amgen | 11,929 | $ 1 | 11,928 | |||
Exchange of common stock for prefunded warrants (in shares) | (1,200,000) | 1,200,000 | ||||
Exchange of common stock for prefunded warrants | 0 | $ (1) | 1 | |||
Issuance of common stock under equity incentive plans (in shares) | 149,759 | |||||
Issuance of common stock under equity incentive plans | 502 | 502 | ||||
Stock-based compensation | 6,240 | 6,240 | ||||
Unrealized (loss) gain on investments | (238) | (238) | ||||
Unrealized (loss) gain on foreign currency translation | (88) | (88) | ||||
Net loss | (50,333) | (50,333) | ||||
Balance at end of period (in shares) at Dec. 31, 2021 | 30,194,279 | |||||
Balance at end of period (in shares) at Dec. 31, 2021 | 1,250,467 | |||||
Balance at end of period at Dec. 31, 2021 | 120,903 | $ 30 | 287,345 | (273) | (166,199) | |
Increase (Decrease) in Stockholders' Equity [Roll Forward] | ||||||
Issuance of common stock in Private Placement/public, net of offering costs (in shares) | 15,509,282 | |||||
Issuance of common stock in Private Placement/public, net of offering costs | 106,706 | $ 16 | 106,690 | |||
Issuance of common stock under equity incentive plans (in shares) | 280,872 | |||||
Issuance of common stock under equity incentive plans | 773 | 773 | ||||
Stock-based compensation | 9,648 | 9,648 | ||||
Unrealized (loss) gain on investments | (901) | (901) | ||||
Unrealized (loss) gain on foreign currency translation | 53 | 53 | ||||
Net loss | $ (57,762) | (57,762) | ||||
Balance at end of period (in shares) at Dec. 31, 2022 | 45,984,433 | 45,984,433 | ||||
Balance at end of period (in shares) at Dec. 31, 2022 | 1,250,467 | 1,250,467 | ||||
Balance at end of period at Dec. 31, 2022 | $ 179,420 | $ 46 | 404,456 | (1,121) | (223,961) | |
Increase (Decrease) in Stockholders' Equity [Roll Forward] | ||||||
Issuance of common stock in Private Placement/public, net of offering costs (in shares) | 9,791,832 | |||||
Issuance of common stock in Private Placement/public, net of offering costs | 152,221 | $ 10 | 152,211 | |||
Issuance of common stock under at the market offering, net of issuance cost (in shares) | 919,413 | |||||
Issuance of common stock under at-the-market offering, net of offering costs | 9,694 | $ 1 | 9,693 | |||
Issuance of common stock under equity incentive plans (in shares) | 940,390 | |||||
Issuance of common stock under equity incentive plans | 4,791 | $ 1 | 4,790 | |||
Exercise of warrants, net of shares withheld (in shares) | 2,711,389 | |||||
Exercise of warrants, net of shares withheld | 1,851 | $ 2 | 1,849 | |||
Stock-based compensation | 10,630 | 10,630 | ||||
Retirement of treasury stock | (1,250,467) | |||||
Unrealized (loss) gain on investments | 1,493 | 1,493 | ||||
Unrealized (loss) gain on foreign currency translation | 25 | 25 | ||||
Net loss | $ (32,184) | (32,184) | ||||
Balance at end of period (in shares) at Dec. 31, 2023 | 60,347,457 | 60,347,457 | ||||
Balance at end of period (in shares) at Dec. 31, 2023 | 0 | 0 | ||||
Balance at end of period at Dec. 31, 2023 | $ 327,941 | $ 60 | $ 583,629 | $ 397 | $ (256,145) |
CONSOLIDATED STATEMENTS OF CASH
CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands | 12 Months Ended | ||
Dec. 31, 2023 | Dec. 31, 2022 | Dec. 31, 2021 | |
Operating activities | |||
Net loss | $ (32,184) | $ (57,762) | $ (50,333) |
Adjustments to reconcile net loss to net cash used in operating activities: | |||
Stock-based compensation expense | 10,630 | 9,648 | 6,240 |
Amortization of premium/discount on investments | (8,051) | (700) | 906 |
Depreciation expense | 576 | 597 | 620 |
Non-cash interest expense | 45 | 178 | 274 |
Realized gain on investments | (33) | 0 | 0 |
Loss on sale of property and equipment | 11 | 93 | 4 |
Deferred income tax | 155 | 46 | (214) |
Changes in operating assets and liabilities: | |||
Accounts receivable | 225 | 24,602 | 0 |
Prepaid expenses and other current assets | 853 | 2,001 | (3,063) |
Operating lease, right-of-use asset | 709 | 618 | 564 |
Accounts payable and accrued liabilities | 6,519 | 5,557 | 5,970 |
Deferred revenue | (57,539) | (27,847) | 24,628 |
Operating lease liability | (928) | (785) | (844) |
Net cash used in operating activities | (79,012) | (43,754) | (15,248) |
Investing activities | |||
Purchases of property and equipment | (487) | (412) | (118) |
Purchase of investments | (351,347) | (266,984) | (133,518) |
Maturities of investments | 296,275 | 154,048 | 81,156 |
Net cash used in investing activities | (55,559) | (113,348) | (52,480) |
Financing activities | |||
Proceeds from sale of common stock and warrants, net of offering costs | 161,905 | 106,716 | 90,733 |
Proceeds from issuance of common stock to Amgen | 0 | 0 | 11,929 |
Proceeds from exercise of stock options, net of taxes paid on vested RSUs | 4,791 | 773 | 502 |
Proceeds from exercise of warrants | 1,851 | 0 | 0 |
Repayment of debt | (3,425) | (4,800) | (2,400) |
Net cash provided by financing activities | 165,122 | 102,689 | 100,764 |
Effect of exchange rate on cash and cash equivalents | 8 | (118) | (88) |
Net increase (decrease) in cash and cash equivalents and restricted cash | 30,559 | (54,531) | 32,948 |
Cash and cash equivalents and restricted cash, beginning of period | 13,630 | 68,161 | 35,213 |
Cash and cash equivalents and restricted cash, end of period | 44,189 | 13,630 | 68,161 |
Supplemental Information | |||
Cash paid for income taxes | 1,535 | 543 | 0 |
Cash paid for interest | $ 66 | $ 322 | $ 554 |
Description of Business
Description of Business | 12 Months Ended |
Dec. 31, 2023 | |
Organization, Consolidation and Presentation of Financial Statements [Abstract] | |
Description of Business | Description of BusinessAlpine Immune Sciences, Inc. (the “Company”, “Alpine”, “we”, “us”, or “our”), together with its consolidated subsidiaries, is a clinical-stage biopharmaceutical company dedicated to discovering and developing innovative, protein-based immunotherapies to treat autoimmune and inflammatory diseases. Our approach includes a proprietary scientific platform that converts native immune system proteins into differentiated, multi-targeted therapeutics. We are seeking to create first- or best-in-class multifunctional immunotherapies via our unique protein engineering technologies to improve outcomes in patients with serious diseases. We were incorporated under the laws of the State of Delaware and are headquartered in Seattle, Washington. |
Summary of Significant Accounti
Summary of Significant Accounting Policies | 12 Months Ended |
Dec. 31, 2023 | |
Accounting Policies [Abstract] | |
Summary of Significant Accounting Policies | Summary of Significant Accounting Policies Basis of Presentation and Use of Estimates The accompanying consolidated financial statements have been prepared in accordance with the rules and regulations of the Securities and Exchange Commission (“SEC”) and generally accepted accounting principles in the United States of America (“GAAP”). The preparation of financial statements in conformity with GAAP requires management to make judgments, estimates and assumptions that affect the amounts reported in the consolidated financial statements and accompanying notes. Significant estimates inherent in the preparation of the accompanying consolidated financial statements include those used for revenue recognition, accruals for clinical trial activities and other accruals, the potential outcome of uncertain tax positions that have been recognized in our consolidated financial statements or tax returns, and the estimated fair value of equity-based awards. We base our estimates and assumptions on historical experience when available and on various factors we believe to be reasonable under the circumstances. Actual results could differ materially from those estimates. Principles of Consolidation Our consolidated financial statements include the financial position and results of operations of Alpine Immune Sciences, Inc. and our wholly owned operating company and subsidiary, AIS Operating Co., Inc., and our wholly owned subsidiary, Alpine Immune Sciences Australia PTY LTD. All inter-company balances and transactions have been eliminated in consolidation. Segments We operate as one operating segment and use cash flow as the primary financial measure to manage our business. Cash and Cash Equivalents and Restricted Cash We consider all highly liquid investments with an original maturity of 90 days or less at the time of purchase to be cash equivalents. Cash and cash equivalents consist of deposits with commercial banks in checking and interest-bearing accounts, highly liquid money market funds, and U.S. Treasury bills. Restricted cash represents cash reserved under our letter of credit, which serves as a security deposit for our operating lease to rent office and laboratory space in Seattle, Washington. Periodically, we maintain deposits in financial institutions in excess of government insured limits. We believe we are not exposed to significant credit risk as our deposits, which are held at financial institutions, are high credit quality securities such as money market funds, U.S. Treasury bills, and commercial paper. To date, we have not realized any losses on these deposits. Investments Our investments include funds invested in highly liquid money market funds, U.S. Treasury bills, U.S. agency securities, non-U.S. government securities, and corporate debt securities and commercial paper with contractual maturities of less than two years. These investments are classified as available-for-sale debt securities, which are recorded at fair value based on quoted prices in active markets for Level 1 assets, and based on market pricing and other observable market inputs for similar securities for Level 2 assets. We classify our investments maturing within one year of the reporting date as short-term investments. If the estimated fair value of a debt security is below its amortized cost basis, we evaluate whether it is more likely than not that we will sell the security before its anticipated recovery in market value and whether credit losses exist for the related securities. A credit loss exists if the present value of expected cash flows is less than the amortized cost basis of the security. Credit-related losses are recognized as an allowance for credit losses on the balance sheet with a corresponding adjustment to earnings. Unrealized gains and losses that are unrelated to credit deterioration are reported in other comprehensive income (loss). Purchase premiums and discounts are recognized within interest income using the interest method over the terms of the securities. Realized gains and losses and declines in fair value for these investments deemed to be expected credit losses are reflected in our Consolidated Statements of Operations and Comprehensive Income (Loss) using the specific-identification method. Property and Equipment Property and equipment are stated at cost, net of accumulated depreciation. Depreciation is recorded using the straight-line method over the estimated useful lives of the assets, generally three Impairment of Long-lived Assets We evaluate our long-lived tangible assets for impairment whenever events or changes in circumstances indicate that the carrying amount of such assets may not be fully recoverable. When such events occur, we assess recoverability by comparing the asset's carrying value to the total undiscounted future cash flows the asset is expected to generate. If the carrying value exceeds the amount of undiscounted cash flows, we then measure impairment by reducing the carrying value to the assets estimated fair value. We did not record any impairments in the years ended December 31, 2023, 2022 or 2021. Accrued Liabilities As part of the process of preparing our consolidated financial statements, we are required to estimate accruals for professional services and research and development expenses. This process involves reviewing contracts and vendor agreements and communicating with applicable personnel to identify services that have been performed on our behalf. We estimate the level of service performed and the associated cost incurred for the service when we have not yet been invoiced or otherwise notified of the actual cost. We estimate accrued liabilities as of each balance sheet date based on known facts and circumstances. Although we do not expect our estimates to be materially different from amounts actually incurred, if our estimates of the status and timing of services performed differ from the actual status and timing of services performed, we may report amounts that are too high or too low in any particular period. To date, we have not experienced any significant adjustments to our estimates. Leases We account for our leases under Accounting Standards Codification (“ASC”) 842, Leases. Under this guidance, we applied the practical expedients regarding the identification of leases, lease classification, indirect costs, and the combination of lease and non-lease components. Arrangements meeting the definition of a lease are classified as operating or financing leases, and are recorded on the consolidated balance sheet as both a right-of-use asset and lease liability, calculated by discounting fixed lease payments over the lease term at the rate implicit in the lease or our incremental borrowing rate. As we do not know the lessor’s implicit rate, we use our incremental borrowing rate at the commencement date of the lease in determining the present value of lease payments. Lease liabilities are increased by interest and reduced by payments each period, and the right-of-use asset is amortized over the lease term. For operating leases, interest on the lease liability and the amortization of the right-of-use asset result in straight-line rent expense over the lease term. For finance leases, interest on the lease liability and the amortization of the right-of-use asset results is front-loaded expense over the lease term. Variable lease expenses are recorded when incurred. We exclude short-term leases having initial terms of 12 months or less as an accounting policy election, and recognize rent expense on a straight-line basis over the lease term. Derivative Financial Instruments We evaluate all of our financial instruments, including prefunded warrants and warrants to purchase common stock, to determine if such instruments are derivatives or contain features qualifying as embedded derivatives. For derivative financial instruments accounted for as liabilities, the derivative instrument is initially recorded at its fair value and is then re-valued at each reporting date, with changes in the fair value reported in the Consolidated Statements of Operations and Comprehensive Income (Loss) . We use the Black-Scholes option-pricing model to value the derivative instruments at inception and subsequent valuation dates. The classification of derivative instruments, including whether such instruments should be recorded as liabilities or as equity, is reassessed at the end of each reporting period. We do not use derivative instruments to hedge exposures to cash flow, market or foreign currency risks. Revenue Recognition Revenue is recognized when control of the promised goods or services is transferred to our customers, in an amount that reflects the consideration we expect to be entitled to in exchange for those goods or services. Our steps for recognizing revenue consist of (1) identifying the contract; (2) identifying the performance obligations as either distinct or bundled goods and services; (3) determining the transaction price associated with each performance obligation for which we expect to be entitled in exchange for transferring such goods and services; (4) allocating the transaction price to the performance obligations in the contract; and (5) recognizing revenue upon satisfaction of performance obligations. Our collaboration agreements principally contain multiple performance obligations, which may include (1) grants of, or options to obtain, intellectual property licenses; (2) research and development services; and/or (3) manufacturing or supply services. Payments received under these arrangements typically include one or more of the following: non-refundable upfront license fees, option exercise fees, payment for research and/or development efforts, amounts due upon the achievement of specified objectives, and/or royalties on future product sales. Our revenue is primarily derived from our collaboration agreements with Adaptimmune Therapeutics plc (“Adaptimmune”), AbbVie Ireland Unlimited Company (“AbbVie”), and Horizon Therapeutics Ireland DAC (acquired by Amgen Inc., or “Amgen,” in October 2023). See further discussion of our collaboration agreements in Note 10 . We allocate revenue to each performance obligation based on its relative stand-alone selling price. We generally determine stand-alone selling prices at the inception of the contract based on our best estimate of what the selling price would be if the deliverable was regularly sold by us on a stand-alone basis. Payments received prior to satisfying the relevant revenue recognition criteria are recorded as deferred revenue in the accompanying Consolidated Balance Sheets and recognized as revenue when the related revenue recognition criteria are met. We recognize revenue under our collaboration agreements by using a cost-based input method to measure progress toward completion of the performance obligation, including employee hours contributed to each performance obligation, and to calculate the corresponding revenue to recognize each period. Our collaboration agreements provide for non-refundable milestone payments. We recognize revenue that is contingent upon the achievement of a substantive milestone in its entirety in the period in which the milestone is achieved. A milestone is considered substantive when the consideration payable to us for such milestone (1) is consistent with our performance necessary to achieve the milestone or the increase in value to the collaboration resulting from our performance; (2) relates solely to our past performance; and (3) is reasonable relative to all of the other deliverables and payments within the arrangement. In making this assessment, we consider all facts and circumstances relevant to the arrangement, including factors such as the scientific, regulatory, commercial, and other risks that must be overcome to achieve the milestone, the level of effort and investment required to achieve the milestone and whether any portion of the milestone consideration is related to future performance or deliverables. We review the contributed employee hours and progress towards completion for each performance obligation under our collaboration agreements, and adjust the revenue recognized to reflect changes in assumptions relating to the estimated satisfaction of the performance obligation. Revenue recognition may be accelerated in the event of early termination of programs or if our expectations change. Alternatively, revenue recognition may be decelerated if programs are extended or delayed. While such changes to our estimates have no impact on our reported cash flows, the timing of revenue recorded in future periods could be materially impacted. Research and Development Research and development costs are expensed as incurred. Research and development costs include personnel costs, clinical trials, external contract research and development expenses, raw materials, drug product manufacturing costs and allocated overhead – including depreciation, rent and utilities. Research and development costs that are paid in advance of performance are capitalized as a prepaid expense and amortized over the service period as the services are provided. Stock-based Compensation Stock-based compensation is recognized for all share-based payments based on the estimated fair value as of the date of grant. The fair value of our stock options is calculated using the Black-Scholes option pricing model, which requires judgmental assumptions including volatility, risk-free interest rate, expected term and dividend yield. The fair value of restricted stock units (“RSUs”) is based on the closing price of our common stock on the award date. Stock-based compensation expense is recognized over the requisite service period of the awards, usually the vesting period, on a straight-line basis. For performance-based awards where the vesting of the options may be accelerated upon the achievement of certain milestones, the related stock-based compensation is recognized as expense when it is probable the milestone will be met. We recognize forfeiture of awards as they occur rather than estimating the expected forfeiture rate. Income Taxes Income taxes are accounted for using an asset and liability approach that requires the recognition of deferred tax assets and liabilities for the expected future tax consequences of temporary differences between the consolidated financial statement and tax bases of assets and liabilities at the applicable enacted tax rates. We establish a valuation allowance for deferred tax assets if it is more likely than not that these items will expire before we are able to realize their benefits or that future deductibility is uncertain. We recognize the tax benefit from uncertain tax positions only if it is more likely than not that the tax position will be sustained on examination by the tax authorities, based on the technical merits of the position. The tax position is measured based on the largest benefit that has a greater than 50% likelihood of being realized upon ultimate settlement. We recognize interest and penalties related to income tax matters in income tax expense, if incurred. Comprehensive Income (Loss) Comprehensive income (loss) is comprised of net loss and certain changes in equity excluded from net loss. For the years ended December 31, 2023, 2022 and 2021, comprehensive income (loss) consisted of unrealized gains and losses on our investments and unrealized gains and losses on foreign currency translation. Foreign Currency Translation Our wholly-owned Australian subsidiary uses the Australian dollar as its functional currency. All assets and liabilities related to this subsidiary are translated using period-end exchange rates, and revenues and expenses are translated at average exchange rates for the year. Translation adjustments are included as components of comprehensive income (loss) in the Consolidated Statements of Operations and Comprehensive Income (Loss) . Recently Issued Accounting Pronouncements In December 2023, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update ("ASU”) 2023-09, Income Taxes (Topic 740): Improvements to Income Tax Disclosures , which requires public entities to disclose disaggregated information about their effective tax rate reconciliation as well as expanded information on income taxes paid by jurisdiction. The disclosure requirements will be applied on a prospective basis, with the option to apply them retrospectively. The standard is effective for annual periods beginning after December 15, 2024, with early adoption permitted. We plan to adopt this guidance for the fiscal year ending December 31, 2025. We are currently evaluating the impact of this new guidance on our disclosure requirements related to the new standard, but do not expect it to have a material impact on our financial condition, results of operations, or cash flows. In November 2023, the FASB issued ASU 2023-07, Segment Reporting (Topic 280): Improvements to Reportable Segment Disclosures , which requires enhanced segment disclosures. Public entities with a single reporting segment are required to provide all disclosures required by Topic 280. This standard is effective for fiscal years beginning after December 15, 2023, and interim periods within fiscal years beginning after December 15, 2024, with early adoption permitted. The enhanced disclosures are required to be applied retrospectively to all prior periods presented in the financial statements. We plan to adopt this guidance for the fiscal year ending December 31, 2024. We are currently evaluating the impact of this new guidance on our disclosure requirements related to the new standard, but do not expect it to have a material impact on our financial condition, results of operations, or cash flows. |
Net Loss Per Share
Net Loss Per Share | 12 Months Ended |
Dec. 31, 2023 | |
Earnings Per Share [Abstract] | |
Net Loss Per Share | Net Loss Per Share Basic net loss per share is computed by dividing net loss by the weighted-average number of common shares outstanding during the period. For each period presented, the increase in the number of shares outstanding impacts the comparability of our net loss per share. The net loss per share for the year ended December 31, 2023 reflects the November 2023 issuance of 9,791,832 shares of common stock in an underwritten public offering, including the subsequent partial exercise of the underwriters’ over-allotment option, 919,413 shares of common stock sold under our at-the-market offering in June 2023, and 2,711,389 shares of common stock issued throughout 2023 related to the exercise of warrants. The net loss per share for the year ended December 31, 2022, reflects the issuance of 15,509,282 shares of common stock sold in an underwritten public offering in September 2022, including the subsequent partial exercise of the underwriters’ over-allotment option in October 2022. The net loss per share for the year ended December 31, 2021, reflects 6,489,357 shares of our common stock issued pursuant to a private placement financing completed in September 2021 and 951,980 shares of our common stock issued in December 2021 pursuant to a private placement financing with Amgen. The common stock issuable upon the conversion or exercise of the following dilutive securities has been excluded from the diluted net loss per share calculation because their effect would have been anti-dilutive. Diluted net loss per share, therefore, is the same as basic net loss per share for the periods presented. December 31, 2023 2022 2021 Common stock warrants 2,369,351 3,656,497 3,666,435 Prefunded warrants to purchase common stock 6,102,127 5,182,197 5,182,197 Stock options and RSUs outstanding 8,013,824 7,236,758 5,877,309 Total 16,485,302 16,075,452 14,725,941 |
Cash Equivalents and Investment
Cash Equivalents and Investments | 12 Months Ended |
Dec. 31, 2023 | |
Cash, Cash Equivalents, and Short-Term Investments [Abstract] | |
Cash Equivalents and Investments | Cash Equivalents and Investments The amortized cost and fair value of our cash equivalents and investments are as follows (in thousands): December 31, 2023 Amortized Cost Gross unrealized gains Gross unrealized losses Fair market value Money market funds $ 31,530 $ — $ — $ 31,530 U.S. treasury bills 217,857 377 (47) 218,187 U.S. agency securities 30,412 14 (57) 30,369 Corporate debt securities and commercial paper 84,425 91 (24) 84,492 Total $ 364,224 $ 482 $ (128) $ 364,578 Classified as: Cash equivalents $ 40,531 Short-term investments 283,491 Long-term investments 40,556 Total $ 364,578 December 31, 2022 Amortized Cost Gross unrealized gains Gross unrealized losses Fair market value Money market funds $ 11,004 $ — $ — $ 11,004 U.S. treasury bills 113,964 5 (721) 113,248 U.S. agency securities 10,921 5 (11) 10,915 Non-U.S. government securities 6,060 — (22) 6,038 Corporate debt securities and commercial paper 129,940 4 (399) 129,545 Total $ 271,889 $ 14 $ (1,153) $ 270,750 Classified as: Cash equivalents $ 11,004 Short-term investments 224,265 Long-term investments 35,481 Total $ 270,750 All investments held as of December 31, 2023 and 2022 were classified as available-for-sale debt securities and consist of highly liquid funds with high credit ratings that, on their date of purchase, had a contractual maturity of two years or less. Realized gains on investments were $33,000 for the year ended December 31, 2023, and zero for the years ended December 31, 2022 and 2021,. There were no realized losses on investments for the years ended December 31, 2023, 2022, or 2021. For investments in an unrealized loss position as of the respective balance sheet dates, the following table summarizes the fair value and gross unrealized losses by category, disaggregated by the length of time that individual debt securities have been in a continuous unrealized loss position (in thousands): December 31, 2023 Less Than 12 Months 12 Months or Greater Total Fair Value Unrealized Losses Fair Value Unrealized Losses Fair Value Unrealized Losses U.S. treasury bills $ 12,779 $ (25) $ 6,994 $ (22) $ 19,773 $ (47) U.S. agency securities 26,248 (57) — — 26,248 (57) Corporate debt securities and commercial paper 27,477 (24) — — 27,477 (24) Total $ 66,504 $ (106) $ 6,994 $ (22) $ 73,498 $ (128) December 31, 2022 Less Than 12 Months 12 Months or Greater Total Fair Value Unrealized Losses Fair Value Unrealized Losses Fair Value Unrealized Losses U.S. treasury bills $ 82,694 $ (368) $ 17,648 $ (353) $ 100,342 $ (721) U.S. agency securities 7,552 (11) — — 7,552 (11) Non-U.S. government securities 3,012 (16) 3,026 (6) 6,038 (22) Corporate debt securities and commercial paper 27,839 (195) 22,171 (204) 50,010 (399) Total $ 121,097 $ (590) $ 42,845 $ (563) $ 163,942 $ (1,153) |
Fair Value Measurements
Fair Value Measurements | 12 Months Ended |
Dec. 31, 2023 | |
Fair Value Disclosures [Abstract] | |
Fair Value Measurements | Fair Value Measurements Cash and cash equivalents, restricted cash, receivables, accounts payable and accrued liabilities, which are recorded at invoiced amount or cost, approximate fair value based on the short-term nature of these financial instruments. Fair value is defined as the exchange price received for an asset or paid to transfer a liability, or an exit price, in the principal or most advantageous market for the asset or liability in an orderly transaction between market participants on the measurement date. Valuation techniques used to measure fair value must maximize the use of observable inputs and minimize the use of unobservable inputs. The three-tier fair value hierarchy, which prioritizes the inputs used in measuring fair value, is as follows: Level 1 : Quoted prices in active markets for identical assets or liabilities. Level 2 : Observable inputs other than Level 1 prices, such as quoted prices for similar assets or liabilities, quoted prices in inactive markets, 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 supported by little or no market activity and significant to the fair value of the assets or liabilities. As of December 31, 2023 and 2022, cash of $3.4 million and $2.4 million, respectively, is excluded from the fair value table below. We had no financial liabilities measured at fair value for the periods presented and the following tables summarize our financial assets measured at fair value on a recurring basis (in thousands): Assets: December 31, 2023 Level 1 Level 2 Level 3 Total Money market funds $ 31,530 $ — $ — $ 31,530 U.S. treasury bills 218,187 — — 218,187 U.S. agency securities — 30,369 — 30,369 Corporate debt securities and commercial paper — 84,492 — 84,492 Total $ 249,717 $ 114,861 $ — $ 364,578 Assets: December 31, 2022 Level 1 Level 2 Level 3 Total Money market funds $ 11,004 $ — $ — $ 11,004 U.S. treasury bills 113,248 — — 113,248 U.S. agency securities — 10,915 — 10,915 Non-U.S. government securities — 6,038 — 6,038 Corporate debt securities and commercial paper — 129,545 — 129,545 Total $ 124,252 $ 146,498 $ — $ 270,750 Our Level 2 assets consist of U.S. agency securities, non-U.S government securities, corporate debt securities, and commercial paper. We review trading activity and pricing for our available-for-sale securities as of the measurement date. When sufficient quoted pricing for identical securities is not available, we use market pricing and other observable market inputs for similar securities obtained from various third-party data providers. These inputs either represent quoted prices for similar assets in active markets or have been derived from observable market data. |
Property and Equipment
Property and Equipment | 12 Months Ended |
Dec. 31, 2023 | |
Property, Plant and Equipment [Abstract] | |
Property and Equipment | Property and Equipment Property and equipment, net, consists of the following (in thousands): December 31, 2023 2022 Laboratory equipment $ 3,472 $ 3,191 General equipment and furniture 459 459 Computer equipment and software 268 217 Leasehold improvements 118 118 Property and equipment, at cost 4,317 3,985 Less accumulated depreciation and amortization (2,833) (2,401) Property and equipment, net $ 1,484 $ 1,584 |
Additional Balance Sheet Inform
Additional Balance Sheet Information | 12 Months Ended |
Dec. 31, 2023 | |
Organization, Consolidation and Presentation of Financial Statements [Abstract] | |
Additional Balance Sheet Information | Additional Balance Sheet Information Prepaid expenses and other current assets consist of the following (in thousands): December 31, 2023 2022 Prepaid research and development $ 1,025 $ 1,881 Prepaid insurance 521 368 Prepaid other 327 394 Other receivables 582 317 Prepaid expenses and other current assets $ 2,455 $ 2,960 Accrued liabilities consist of the following (in thousands): December 31, 2023 2022 Research and development services $ 12,838 $ 7,657 Employee compensation 7,970 4,110 Legal and professional fees 283 334 Accrued taxes 4 1,847 Accrued other 92 55 Accrued liabilities $ 21,187 $ 14,003 |
Long-term Debt
Long-term Debt | 12 Months Ended |
Dec. 31, 2023 | |
Debt Disclosure [Abstract] | |
Long-term Debt | Long-term Debt In August 2019, we entered into an Amended and Restated Loan and Security Agreement (the “Loan Agreement”) with Silicon Valley Bank (“SVB”), pursuant to which SVB agreed to extend term loans to us with an aggregate principal amount of up to $15.0 million (the “Term Loans”). Borrowings under the Loan Agreement consisted of up to three separate tranches. The initial tranche of $5.0 million was funded in August 2019, the second tranche of $5.0 million was funded in March 2020, and we did not draw down the final tranche of $5.0 million, which expired in July 2020. The Term Loans accrued interest at a floating per annum rate of 0.25% above the prime rate, subject to a floor of 5.75%, payable monthly commencing in September 2019. The Term Loans were interest only until September 30, 2020, however, under the Loan Agreement our interest only period automatically extended to June 30, 2021, if we received aggregate new capital of at least $40.0 million no later than June 30, 2020. We met this milestone in June 2020 in conjunction with the execution of our agreement with AbbVie, discussed in detail in Note 10 . In connection with the Loan Agreement, we issued SVB warrants to purchase up to 52,083 shares of our common stock at a price of $4.32 per share, 17,361 shares of which became exercisable in August 2019 after we drew down the initial tranche. In March 2020, after we drew down the second tranche of our Term Loans, an additional 17,361 shares became exercisable. The remaining warrants did not vest and expired upon the expiration of the third tranche of our Term Loans. The fair value of the warrants on the date of issuance for the initial tranche and second tranche was $60,000 and $60,000, respectively, determined using the Black-Scholes option-pricing model, and was recorded as a component of equity and as a debt discount in our accompanying Consolidated Balance Sheets . In May 2023, we voluntarily repaid in full the remaining outstanding carrying value of $1.4 million of our Term Loans, which consisted of $800,000 in principal and final payments of $625,000, plus prorated accrued interest. In connection with the debt payoff, we wrote-off the remaining unamortized debt discount. As of December 31, 2023, we had no remaining balance outstanding under our Loan Agreement with SVB. |
Commitments and Contingencies
Commitments and Contingencies | 12 Months Ended |
Dec. 31, 2023 | |
Commitments and Contingencies Disclosure [Abstract] | |
Commitments and Contingencies | Commitments and Contingencies Operating Leases In March 2019, we entered into a lease for office and laboratory space located at 188 East Blaine Street, Seattle, Washington. The term of the lease is 10.8 years with one option to extend the term by 5.0 years. Our option to extend the rental term of our lease was not considered reasonably certain as of December 31, 2023. The lease term commenced in June 2019. The “Rent Commencement Date” began in March 2020, nine months after the commencement date. The annual base rent under the lease is $1.7 million for the first year and will increase by 3.0% each year thereafter. We were not required to pay base rent from the Rent Commencement Date through November 2020, the last day of the ninth month following the Rent Commencement Date. We received a tenant improvement allowance of $5.4 million, which is included in our base rent, and a maximum additional tenant improvement allowance of $1.8 million, which will result in additional rent amortized over the term of the lease at an annual rate of 8.0%. The lease also requires us to pay additional amounts for operating and maintenance expenses. In connection with the lease, we have provided to our landlord a $254,000 letter of credit as a security deposit, which is recorded as noncurrent restricted cash in our accompanying Consolidated Balance Sheets . As of December 31, 2023 , our operating lease right-of-use assets and operating lease liability associated with our lease were $7.5 million and $9.9 million, respectively. Supplemental operating lease information is as follows (in thousands): Years Ended December 31, 2023 2022 2021 Operating lease cost $ 1,843 $ 1,839 $ 1,837 Variable lease cost 917 823 603 Total lease cost $ 2,760 $ 2,662 $ 2,440 Other information: Cash paid for amounts included in the measurement of lease liabilities $ 2,062 $ 2,009 $ 2,117 Weighted-average remaining lease term (years) 6.2 7.2 8.2 Weighted-average discount rate 10.7% 10.7% 10.7% Variable lease costs represent our share of the landlord’s operating expenses. We do not act as a lessor or have any leases classified as financing leases. Maturities of our operating lease liabilities as of December 31, 2023, are as follows (in thousands): Minimum Lease Payments 2024 $ 1,939 2025 2,167 2026 2,224 2027 2,283 2028 2,344 Thereafter 2,811 Total future minimum lease payments 13,768 Less: imputed interest (3,854) Operating lease liabilities $ 9,914 Contingencies Certain credits received related to our research and development expenditures, which were previously recorded within other income within our Consolidated Statements of Operations and Comprehensive Income (Loss) , were subject to review by foreign taxing authorities. We reached constructive agreement with the Australian Taxation Office (the “ATO”) during 2022 and recorded an estimated current foreign income tax provision of $1.3 million for the expected repayments, of which we paid $590,000 and $543,000 during the years December 31, 2023, and 2022, respectively. In 2023, the remaining balance of $136,000 was fully offset by research and development tax credits by the ATO, which were recorded within other income in our Consolidated Statements of Operations and Comprehensive Income (Loss) . As of December 31, 2023, we have no further liabilities associated with the ATO. |
License and Collaboration Agree
License and Collaboration Agreements | 12 Months Ended |
Dec. 31, 2023 | |
Organization, Consolidation and Presentation of Financial Statements [Abstract] | |
License and Collaboration Agreements | License and Collaboration Agreements AbbVie In June 2020, we entered into an option and license agreement with AbbVie (as amended, the “AbbVie Agreement”) for the development of ALPN-101 (“acazicolcept”). which grants AbbVie an exclusive option to take an exclusive license to acazicolcept (the “License Option”). In December 2023, we and AbbVie amended the AbbVie Agreement (the “AbbVie Amendment”) and agreed to stop enrollment in our global, randomized, double-blind, placebo-controlled Phase 2 study of acazicolcept in adults with moderate-to-severe SLE (“Synergy”) to allow for an early assessment of the study’s clinical trial data. Currently enrolled patients will be allowed to complete their study treatment protocol. Amended payment terms are discussed below. Under the AbbVie Agreement, the License Option is exercisable by AbbVie at any time and will expire 90 days from the delivery of an agreed-upon data package by us to AbbVie. If AbbVie exercises the License Option, AbbVie will take over the future development and commercialization. Prior to the exercise of the License Option, we will perform research and development services, including completing our remaining deliverables under the Synergy study, based on an agreed-upon development plan (the “Development Plan”). We are fully responsible for all costs incurred to conduct the activities under the Development Plan, provided that, AbbVie may be responsible for increased costs under the Development Plan in connection with certain material amendments, if proposed by AbbVie. We are also responsible, at our sole cost and expense, for manufacturing and regulatory filings for acazicolcept necessary to complete activities under the Development Plan. In June 2020, in connection with the execution of the AbbVie Agreement, AbbVie paid us a nonrefundable upfront payment of $60.0 million. Prior to the exercise of the License Option, AbbVie also agreed to make cash payments upon our achievement of certain development milestones (the “Alpine Development Milestones”) up to an aggregate amount of $75.0 million, of which $45.0 million was achieved in 2021, and the remaining $30.0 million was removed under the AbbVie Amendment. If AbbVie exercises the License Option, they will pay a one-time cash payment of $10.0 million (reduced from $75.0 million under the AbbVie Agreement). Following the exercise of the License Option, AbbVie has furthermore agreed to make aggregate cash payments per the AbbVie Amendment of up to $153.8 million upon AbbVie’s achievement of certain development and commercial milestones and additional aggregate cash payments of up to $337.5 million upon AbbVie’s achievement of certain sales-based cash milestones, collectively referred to as the “AbbVie Milestones”. Lastly, subsequent to commercialization, we are also eligible to receive mid-single-digit percentage royalties on worldwide net sales of licensed products. For revenue recognition purposes, we determined that our contractual promises in the AbbVie Agreement are not distinct and are interdependent with our performance obligation to provide research and development services under the Development Plan. Thus, all contractual promises related to the upfront payment and Alpine’s Development Milestones were combined into a single performance obligation. We determined the Alpine Development Milestone payments are probable of significant revenue reversal as the achievement is highly dependent on factors outside our control. Therefore, these milestone payments were fully constrained and were not initially included in the transaction price. In June 2021, we re-evaluated and updated the transaction price to include the achieved portion of the Alpine Development Milestones. We will continue to re-evaluate the transaction price each reporting period and update as uncertain events are resolved or other changes in circumstances occur. We expect to recognize the remaining deferred revenue over the remaining life of the Development Plan, which began in June 2020 and ends upon the later of the exercise or expiration of the option. The License Option and the AbbVie Milestones were determined not to be performance obligations at the inception of the contract as they did not represent material rights. If exercised, the License Option and AbbVie Milestones will be accounted for as a separate contract and will be recognized as revenue if and when triggered. Any consideration related to sales-based royalties and profit-sharing payments will be recognized when the related sales occur. Amgen In December 2021, we entered into an exclusive license and collaboration agreement with Amgen (the “Amgen Agreement”) for the development, manufacture, and commercialization of up to four preclinical candidates generated from our unique discovery platform. The agreement includes licensing of one of our existing preclinical biologic therapeutic programs (the “Existing Program”), as well as a research partnership to jointly develop candidates for up to three additional autoimmune and inflammatory disease programs for other designated biological targets (the “Research Programs”). These candidates include previously undisclosed multi-specific fusion protein-based therapeutic candidates for autoimmune and inflammatory diseases. We will advance candidate molecules to predefined preclinical milestones while Amgen will be responsible for the respective costs and, ultimately, Amgen will assume responsibility for development and commercialization activities and costs. In connection with the execution of the Amgen Agreement in December 2021, we entered into a stock purchase agreement under which Amgen purchased 951,980 shares of our common stock in a private placement for approximately $15.76 per share and aggregate proceeds of $15.0 million. The shares were sold at a 25% premium to the volume-weighted average share price of our common stock for a specified 30-day period prior to entering into the agreement. The fair value of the common stock issued to Amgen of $11.9 million was recorded to equity, based on the closing price of common stock on the effective date of the Amgen Agreement. For accounting purposes, the $3.1 million difference between the cash proceeds and the fair value of the common stock was treated as additional consideration attributable to the Amgen Agreement. Under the terms of the agreement, Amgen also paid us a non-refundable upfront payment of $25.0 million in the first quarter of 2022. As of December 31, 2023, we have completed our activities under the Existing Program. We continue to support activities related to the First Research Program. In January 2024, we received a termination notification from Amgen for the non-exclusive license to use the Second Research Program. A Third Research Program was not selected by the respective option deadline. In addition, we are eligible to receive up to $381.0 million per program, or a total of approximately $762.0 million for the remaining programs, in future success-based payments related to development, regulatory and commercial milestones. Furthermore, we are eligible to receive tiered royalties from a mid-single digit percentage to a low double-digit percentage on global net sales. In addition to proceeds from the non-refundable upfront payment, we have recognized $2.1 million in research and development support provided by us through December 31, 2023. For revenue recognition purposes, we determined the transaction price at inception was $28.1 million, which consists of the upfront payment of $25.0 million and the $3.1 million premium on the stock purchase, and that the Existing Program and each Research Program are distinct performance obligations. We allocated revenue to each performance obligation based on its relative stand-alone selling price. The future success-based payments related to development and regulatory milestones are probable of significant revenue reversal as the achievement is highly dependent on factors outside our control. Therefore, these milestone payments are fully constrained and are not initially included in the transaction price. We will continue to re-evaluate the transaction price each reporting period and update as uncertain events are resolved or other changes in circumstances occur. Any consideration related to commercial milestones and royalties will be recognized when the related sales occur. Adaptimmune In May 2019, we entered into a collaboration and licensing agreement with Adaptimmune (the “Adaptimmune Agreement”) to develop next-generation SPEAR T cell products. Under this agreement, we performed certain research services and granted Adaptimmune a worldwide exclusive license to programs from our secreted immunomodulatory protein and transmembrane immunomodulatory protein technologies. Through December 31, 2023, we have recorded a total of $3.0 million in license payments under the terms of the Adaptimmune Agreement, consisting of a $2.0 million upfront license payment received in June 2019, and an additional $1.0 million license fee upon Adaptimmune’s selection of an additional research program in June 2022. Furthermore, through December 31, 2023, we have recorded $2.1 million in research support payments received in connection with research services completed by us. If respective pre-specified milestones for each of the two active research programs are achieved, we are eligible for downstream development and commercialization milestones of up to an aggregate amount of $105.0 million, and we are also eligible to receive low-single digit percentage royalties on worldwide net sales of the applicable products. Contract balances and revenue recognition We report contract assets resulting from unconditional rights to consideration related to upfront payments, and for completed but unpaid research and development services within accounts receivable in our accompanying Consolidated Balance Sheets . Contract liabilities, representing advance consideration for licensing rights bundled with research and development services and other promises for which the underlying performance obligations have not yet been satisfied, are reported as deferred revenue in our accompanying Consolidated Balance Sheets . Contract liabilities are presented as current and noncurrent based on estimated timing of when the underlying performance obligations will be met. Respective balances are as follows (in thousands): December 31, 2023 2022 Contract Assets $ 167 $ 392 Contract Liabilities $ 17,217 $ 74,756 We use cost-based input methods to measure progress towards completion of our performance obligations and to calculate the corresponding revenue to recognize under our contracts with customers each period. In applying the cost-based input, we use actual costs incurred relative to budgeted costs for each combined performance obligation. Actual costs consist primarily of labor related to internal personnel, and third-party contracts. Revenue is recognized based on the percentage of costs incurred relative to the total estimated costs for the performance obligation. A cost-based input method of revenue recognition requires management to estimate the costs to complete our performance obligations. In making such estimates, significant judgment is required to evaluate assumptions related to cost estimates. The cumulative effect of revisions to estimated costs to complete our performance obligations will be recorded in the period in which changes are identified and amounts can be reasonably estimated. A significant change in these assumptions and estimates could have a material impact on the timing and amount of revenue recognized in future periods. Collaboration revenue recognized in our accompanying Consolidated Statements of Operations and Comprehensive Income (Loss) , disaggregated by customer, is as follows (in thousands): Years Ended December 31, 2023 2022 2021 AbbVie $ 41,925 $ 17,064 $ 23,443 Amgen 16,487 11,964 — Adaptimmune 464 1,036 — Total collaboration revenue $ 58,876 $ 30,064 $ 23,443 Revenue recognized during the period that was included in the opening contract liab ility balance was $57.5 million, $28.2 million and $23.4 million for the years ended December 31, 2023, 2022 and 2021, respectively. For 2023, the decrease in the contract liability balance includes a cumulative catch-up adjustment of $20.4 million recognized upon the contract modification related to the AbbVie Amendment, which resulted in down ward revision of the projected program duration and a corresponding decrease in total direct and indirect development costs to complete the program, and $6.7 million in revenue recognized under the Amgen Agreement upon expiration of Amgen’s option to select an additional Third Research Program. For 2022, the change in the contract liability balance for AbbVie was reduced by a cumulative catch-up adjustment related to upward revisions to the projected program duration and corresponding increase in estimated total direct and indirect development costs to complete the program. |
Stockholders' Equity
Stockholders' Equity | 12 Months Ended |
Dec. 31, 2023 | |
Equity [Abstract] | |
Stockholders’ Equity | Stockholders’ Equity Common Stock Shares of common stock reserved for future issuance were as follows: December 31, 2023 2022 Shares to be issued upon exercise of outstanding stock options 7,968,360 7,058,140 Shares to be issued upon release of RSUs 45,464 178,618 Shares to be issued upon conversion of common stock warrants 2,369,351 3,656,497 Shares to be issued upon conversion of prefunded warrants 6,102,127 5,182,197 Shares available for future stock grants 281,984 314,523 Shares to be issued under employee stock purchase plan 45,211 45,211 Shares of common stock reserved for future issuance 16,812,497 16,435,186 Securities Offerings In November 2023, we sold an aggregate of 9,791,832 shares of our common stock (the “2023 Shares”) and prefunded warrants to purchase 3,200,000 shares of common stock (the “2023 Prefunded Warrants”) in an underwritten public offering, including the subsequent partial exercise of the underwriters’ over-allotment option, pursuant to our effective shelf registration statement on Form S-3 (File No. 333-271517). The purchase price for each 2023 Share and 2023 Prefunded Warrant was $12.50 and $12.499 per share, respectively, for an aggregate purchase price of $162.4 million. The 2023 Prefunded Warrants became fully exercisable upon the closing date and have an exercise price of $0.001 per share. In connection with this offering, we received net proceeds of $152.2 million after deducting underwriting discounts, commissions and offering costs. Offering costs of $440,000 were netted against the proceeds within additional-paid-in-capital on our accompanying Consolidated Balance Sheets . In September 2022, we sold an aggregate of 15,509,282 shares of our common stock in an underwritten public offering, including the subsequent partial exercise of the underwriters’ over-allotment option in October 2022, pursuant to our effective shelf registration statement on Form S-3 (File No. 333-256107). We received resulting net proceeds of $106.7 million after deducting underwriting discounts, commissions and offering costs. Offering costs of $438,000 were netted against the proceeds within additional-paid-in-capital on our accompanying Consolidated Balance Sheets . In September 2021, we entered into a securities purchase agreement (the “2021 Securities Purchase Agreement”) for a private placement with a select group of institutional investors, pursuant to which we sold 6,489,357 shares of our common stock (the “2021 Shares”) and prefunded warrants to purchase 3,191,487 shares of common stock (the “2021 Prefunded Warrants”). The purchase price for each 2021 Share and for each 2021 Prefunded Warrant was $9.40 per share, for an aggregate purchase price of approximately $91.0 million. The 2021 Prefunded Warrants became fully exercisable upon the closing date and have an exercise price of $0.001 per share. We incurred $266,000 in offering costs associated with the 2021 Securities Purchase Agreement, which was netted against the proceeds within additional-paid-in-capital on our accompanying Consolidated Balance Sheets . The securities sold and issued under the 2021 Securities Purchase Agreement have not been registered under the Securities Act of 1933, as amended, or state securities laws and may not be offered or sold in the United States absent registration with the SEC or an applicable exemption from such registration requirements. We filed a registration statement for the 2021 Securities Purchase Agreement with the SEC, which was declared effective by the SEC in November 2021 and covers the resale of the shares of common stock issuable in connection with the private placements and upon exercise of the warrants. In September 2021, we entered into an exchange agreement (the “Exchange Agreement”) with Frazier Life Sciences VIII, L.P. (the “Exchanging Stockholder”), which Exchanging Stockholder is affiliated with a member of our board of directors, pursuant to which we exchanged an aggregate of 1,200,000 shares of common stock held by the Exchanging Stockholder for prefunded warrants (the “Exchange Warrants”) to purchase an aggregate of 1,200,000 shares of common stock. Upon the closing of the exchange, we reclassified 1,200,000 shares of common stock into treasury stock on our accompanying Consolidated Balance Sheets . Financing Agreements In April 2023, we entered into a sales agreement (the “2023 Sales Agreement”) with Cowen and Company, LLC (“TD Cowen”) to sell shares of our common stock, from time to time, through an “at-the-market” equity offering for up to $100.0 million in aggregate gross proceeds. TD Cowen will act as the sales agent and will be entitled to compensation for services of up to 3.0% of the gross sales proceeds from shares sold through TD Cowen under the 2023 Sales Agreement. The shares will be issued pursuant to our shelf registration statement on Form S-3 (File No. 333-271517), which was filed with the SEC on April 28, 2023, and declared effective on May 9, 2023. On May 11, 2023, we filed a final prospectus supplement with the SEC relating to the offer and sale of the shares pursuant to the 2023 Sales Agreement. As of December 31, 2023, we have sold 919,413 shares of common stock under the 2023 Sales Agreement for a price of $10.93 per share. The associated gross proceeds of $10.0 million were recorded net of directly related offering costs of $355,000 within additional-paid-in-capital on our accompanying Consolidated Balance Sheets . In September 2022, we and TD Cowen mutually terminated our prior sales agreement (the “2021 Sales Agreement”), which we had entered into in July 2021. The 2021 Sales Agreement provided that we may sell shares of our common stock from time to time through an “at-the-market” equity offering for up to $75.0 million in gross cash proceeds, with TD Cowen acting as the sales agent. No common stock was sold under the 2021 Sales Agreement. In connection with the termination of the 2021 Sales Agreement, we wrote off $488,000 of deferred offering costs to expense, which were previously included within prepaid expenses and other current assets on our accompanying Consolidated Balance Sheets . Treasury Shares In June 2023, we retired 1,250,467 shares of treasury stock, and returned the shares of common stock to the status of authorized but unissued shares. Warrants We have issued warrants in connection with our securities offerings, SVB loans, and to certain non-employee professional advisers. Excluding the prefunded warrants we issued in connection with our securities offerings discussed above, the table below summarizes our common stock warrant activity: Warrants Weighted- Weighted- Outstanding at December 31, 2022 3,656,497 $ 12.66 1.12 Exercised (1,287,146) 12.74 Outstanding and Exercisable at December 31, 2023 2,369,351 $ 12.62 0.15 In January 2024, we issued 1,694,282 shares of common stock and received $17.6 million in proceeds in connection with exercises of 2,309,404 of our common stock warrants. In addition, in February 2024, we issued 3,199,879 shares of common stock in connection with the exercise of 3,200,000 of our prefunded warrants. Equity Incentive Plans Our board of directors has approved “inducement” grants, pursuant to Rule 5635(c)(4) of the Nasdaq Listing Rules, which are exempt from registration under the Securities Act of 1933, as amended, pursuant to Section 4(a)(2). In August 2023, we issued an “inducement” option grant to purchase 185,000 shares of our common stock at a per-share exercise price of $13.44 to our Chief Technology Officer. In August 2022, we issued an “inducement” option grant to purchase 160,000 shares of our common stock at a per-share exercise price of $8.38 to our Chief Medical Officer. In June 2018, our stockholders approved the 2018 Equity Incentive Plan (the “2018 Plan”). Upon adoption, we ceased granting stock awards under the Nivalis Therapeutics, Inc. 2015 Equity Incentive Plan (the “2015 EIP”) and the Amended and Restated 2015 Stock Plan, collectively, the “Legacy Plans”. All shares of common stock subject to awards under the Legacy Plans that expire or terminate without having been exercised in full, or are forfeited to or repurchased by the company, will be added to the 2018 Plan, up to a maximum of 1,972,784 shares. Under our 2018 Plan we may issue stock options, stock appreciation rights, restricted stock, RSUs or performance shares. As of December 31, 2023, we have only issued stock options and RSUs. Our 2018 Plan provides for an annual increase in the number of shares reserved for issuance equal to the lesser of (1) 5% of the number of shares of common stock outstanding as of the last day of the preceding calendar year or (2) 1,500,000. However, our board of directors may act prior to January 1 of a given year to provide that there will be no January 1 increase for such year or that the increase for such year will be a lesser number of shares. On January 1, 2024, a total of 1,500,000 additional shares was automatically added to the shares authorized under the 2018 Plan. In July 2017, in connection with the merger with Nivalis, we assumed Nivalis’ Employee Stock Purchase Plan (the “ESPP”) and the 2015 EIP. Upon assumption of the ESPP, there were 45,211 shares available for issuance under the ESPP. As of December 31, 2023, we have not activated the ESPP. Stock options granted to our employees under our equity plans generally vest within four years, and vested options are exercisable from the vest date until ten years after the date of grant. Vesting of certain employee options may be accelerated in the event of a change in control of the Company. We grant stock options to employees with exercise prices equal to the fair value of our common stock on the date of grant. The term of incentive stock options may not exceed ten years from the date of grant. As of December 31, 2023, a total of 9,616,862 shares of common stock were authorized for issuance under our 2018 Plan and Legacy Plans. A summary of stock option activity under our plans is presented below: Options Weighted- Weighted- Aggregate Outstanding at December 31, 2022 7,058,140 $ 8.37 Granted 2,816,197 $ 9.50 Exercised (858,511) $ 5.91 Forfeited (1,047,466) $ 10.40 Outstanding at December 31, 2023 7,968,360 $ 8.77 6.96 $ 82,254 Vested and expected to vest after December 31, 2023 7,790,360 $ 8.79 6.95 $ 80,307 Exercisable at December 31, 2023 4,462,145 $ 7.79 5.62 $ 50,542 The aggregate intrinsic value of stock options exercised during the years ended December 31, 2023, 2022 and 2021 was $7.6 million, $1.1 million and $546,000, respectively. The fair value of stock options vested during the years ended December 31, 2023, 2022 and 2021 was $9.6 million, $8.6 million and $3.4 million, respectively. A summary of our RSU activity under our plans is presented below: Number of Shares Weighted- Weighted- Aggregate Non-vested at December 31, 2022 178,618 $ 12.00 Vested (114,651) $ 12.00 Forfeited (18,503) $ 12.00 Non-vested at December 31, 2023 45,464 $ 12.00 0.0 $ 867 The aggregate intrinsic value of RSUs vested during the years ended December 31, 2023 and 2022 was $1.0 million and $527,000, respectively. The fair value of RSUs vested during the years ended December 31, 2023 and 2022 was $1.4 million and $735,000, respectively. No RSUs vested during the year ended December 31, 2021. We utilize newly issued shares to satisfy option exercises and RSU releases. As of December 31, 2023, the re was $22.4 million of unrecognized stock-based compensation expense related to approximately 3.6 million nonvested stock options and RSU awards that is expected to be recognized over a weighted-average remaining period of 2.7 years. Stock-Based Compensation Expense We use the Black-Scholes option pricing model to estimate the fair value of stock options at the grant date. The fair value of RSUs is equal to the closing stock price on the date of grant. The Black-Scholes option pricing model requires us to make certain estimates and assumptions, including assumptions related to the expected price volatility of our stock, the period during which the options will be outstanding, the rate of return on risk-free investments, and the expected dividend yield of our stock. The fair values of stock options granted to employees were calculated using the following assumptions: Years Ended December 31, 2023 2022 2021 Weighted-average estimated fair value at grant $6.94 $7.56 $8.44 Risk-free interest rate (1) 3.36% - 4.67% 1.39% - 4.04% 0.25% - 1.3% Expected term of options (in years) (2) 5.27 - 6.08 5.27 – 6.08 3.49 – 6.08 Expected stock price volatility (3) 81% - 85% 80% - 83% 79% - 83% Expected dividend yield (4) —% —% —% (1) The risk-free interest rate assumption was based on zero-coupon U.S. Treasury instruments that had terms consistent with the expected term of our stock option grants. (2) We used the “simplified method” for options to determine the expected term of stock options granted, since we do not have sufficient historical exercise data to provide a reasonable basis upon which to estimate expected term due to the limited time our shares have been publicly traded. Under this approach, the weighted-average expected life is presumed to be the average of the vesting term and the contractual term of the option. (3) Volatility is a measure of the amount by which a financial variable, such as share price, has fluctuated or is expected to fluctuate during a period. We analyzed the historical stock price volatility of companies at a similar stage of development to estimate the expected volatility of our stock price. (4) We have never declared or paid any cash dividends and do not presently plan to pay cash dividends in the foreseeable future. Stock-based compensation expense is classified in the Consolidated Statements of Operations and Comprehensive Income (Loss) as follows (in thousands): Years Ended December 31, 2023 2022 2021 Research and development $ 6,251 $ 5,713 $ 3,347 General and administrative 4,379 3,935 2,893 Total stock-based compensation expense $ 10,630 $ 9,648 $ 6,240 |
Income Taxes
Income Taxes | 12 Months Ended |
Dec. 31, 2023 | |
Income Tax Disclosure [Abstract] | |
Income Taxes | Income Taxes Our loss before taxes is derived from domestic (United States) and foreign (Australian) sources as follows (in thousands): Years Ended December 31, 2023 2022 2021 Domestic $ (32,450) $ (55,475) $ (48,932) Foreign 369 43 (1,488) Total $ (32,081) $ (55,432) $ (50,420) The provision for income taxes is composed of the following (in thousands): Years Ended December 31, 2023 2022 2021 Current: U.S. - Federal $ 47 $ (981) $ — U.S. - State 4 (16) — Foreign — (1,285) (129) Total current 51 (2,282) (129) Deferred: Foreign (154) (48) 216 Total deferred (154) (48) 216 Total income tax (expense) benefit $ (103) $ (2,330) $ 87 The effective tax rate of the provision for income taxes differs from the federal statutory rate as follows: Years Ended December 31, 2023 2022 2021 U.S. Statutory rate 21.0 % 21.0 % 21.0 % Effect of: State taxes (net of federal benefit) 0.3 % 0.1 % — % Permanent differences 0.3 % — % (0.4) % Federal research and development credit 9.2 % 5.0 % 4.5 % Change in valuation allowance (29.1) % (28.6) % (21.4) % Global intangible low-taxed income recapture — % (0.6) % (1.4) % Stock-based compensation (1.6) % (1.9) % (1.8) % Foreign rate differential (0.1) % — % 0.2 % Other (0.3) % — % (0.5) % Voluntary disclosure net change in prior years’ tax liabilities — % 0.8 % — % Effective income tax rate (0.3) % (4.2) % 0.2 % For the year ended December 31, 2023, tax expense of $103,000 primarily represents deferred tax expense from the application of a full valuation allowance against our remaining foreign deferred tax assets, partially offset by the recognition of current income tax benefits resulting from the finalization of our prior period tax returns. For the year ended December 31, 2022, $1.0 million of our tax expense represents the recognition of current domestic federal and state income tax liabilities, which was a result of the mandatory capitalization of research and development expenses under Internal Revenue Code (the “IRC”) Section 174. As part of the Tax Cuts and Jobs Act of 2017, beginning with the 2022 tax year, expenses that are incurred for research and development in the U.S. will be capitalized and amortized over five years, and expenses that are incurred for research and experimentation outside the U.S. will be capitalized and amortized over 15 years. For the year ended December 31, 2022, $1.3 million of our tax expense represents the recognition of current tax liabilities, which were the result of a cumulative change to our foreign income tax provision for the activities of Alpine Immune Sciences Australia PTY LTD. In June 2022, Alpine Immune Sciences Australia PTY LTD’s was notified that the tax return filed under a revised transfer pricing model was accepted for the six-month period ended December 31, 2019. Following the acceptance notification, the tax provisions for each open tax year have been recalculated using the same transfer pricing methodology underlying the accepted return. Additionally, consistent with the change to our transfer pricing methodology, we recorded $48,000 of deferred tax expense resulting from a reduction to our deferred tax assets for the year ended December 31, 2022. The $87,000 tax benefit for the year ended December 31, 2021, represents deferred tax benefits resulting from the finalization of our prior-period tax returns and the removal of the valuation allowance in place against our foreign deferred tax assets, partially offset by income tax expense for current year activity. For the years ended December 31, 2023, 2022, and 2021, the difference between the U.S. federal statutory tax rate of 21% and our effective tax rates in all periods is primarily due to changes in our valuation allowance related to our deferred tax assets and the generation and consumption of federal research and development tax credits. We have elected to treat taxes due on future U.S. inclusions in taxable income under the global intangible low-taxed income (the “GILTI”) provision as a current-period expense when incurred. As such, expected future GILTI inclusions have not been factored into the measurement of our deferred taxes. Deferred income taxes reflect the net tax effects of temporary differences between the carrying amounts of assets and liabilities for financial reporting purposes and the amounts used for income tax purposes. The following table represents the significant components of our deferred tax assets and liabilities for the periods presented (in thousands): December 31, 2023 2022 Deferred tax assets: Net operating loss $ 23,205 $ 18,590 Research and development credits 9,259 6,240 Intangible asset basis 4 2 Lease liability 2,126 2,315 Deferred revenue 3,600 14,752 Stock based compensation 2,428 2,343 Capitalized research and experimental costs 24,147 12,681 Other 1,088 156 Gross deferred tax assets 65,857 57,079 Valuation allowance (63,897) (54,841) Total deferred tax assets, net of valuation allowance 1,960 2,238 Deferred tax liabilities: Prepaid expenses (251) (173) Fixed asset basis (126) (182) Right-of-use asset basis (1,583) (1,728) Total deferred tax liability (1,960) (2,083) Net deferred tax assets and liabilities $ — $ 155 A valuation allowance is provided for deferred tax assets where the recoverability of the assets is uncertain. The determination to provide a valuation allowance is dependent upon the assessment of whether it is more likely than not that sufficient taxable income will be generated to utilize the deferred tax assets. For the year ended December 31, 2023, we determined that based on an evaluation of our sources of income and all available evidence, both positive and negative, including our latest forecasts and cumulative losses in recent years, it was more likely than not that none of our domestic deferred tax assets would be realized and therefore we continued to record a full valuation allowance. For the year ended December 31, 2023, we determined that it was more likely than not that none of our foreign deferred tax assets would be realized. As such, we have recorded a full valuation allowance against all foreign deferred tax assets. The valuation allowance increased by $9.1 million and $16.1 million during the years ended December 31, 2023 and 2022, respectively. We have net operating loss (“NOL”) carryforwards as follows (in thousands): December 31, 2023 2022 Federal (after January 1, 2018) $ 108,393 $ 85,012 State $ 6,778 $ 6,433 Federal NOL carryforwards created after January 1, 2018, carry forward indefinitely, and our state NOL carryforwards begin to expire in 2038. We have net research and development tax credit carryforwards as follows (in thousands): December 31, 2023 2022 Federal $ 11,584 $ 7,892 Foreign $ 578 $ 527 Federal research and development tax credit carryforwards begin to expire in 2035, and our foreign research and development tax credits carry forward indefinitely. Current tax laws impose substantial restrictions on the utilization of research and development credit and NOL carryforwards in the event of an ownership change, as defined by the IRC Section 382 and 383. Such an event may limit our ability to utilize NOLs and research and development tax credit carryforwards. We have commissioned Section 382 studies, focused on AIS Operating Co., Inc., evaluating changes in ownership for periods from inception through December 31, 2023. We concluded that we experienced ownership changes on June 10, 2016, and September 17, 2021, and as a result, our ability to use research and development tax credit and NOL carryforwards created prior to September 17, 2021, has been limited. We have incorporated the resulting limitations into our provision for income taxes for the years ended December 31, 2023 and 2022. Though limited in the amount which can be utilized for the year ended December 31, 2023, and annually thereafter, the restrictions do not definitively prevent the impacted research and development tax credit carryforwards from utilization in future years and before expiration. As such, we have not reduced our research and development tax credit carryforwards as of December 31, 2023. Additionally, under IRC Section 382 and 383, the 2017 merger with Nivalis is likely considered an ownership change with respect to the potential limitation of the Nivalis federal tax credits and NOLs. As such, it is likely that any future utilization of Nivalis federal tax credits and NOLs is substantially limited. Therefore, as of December 31, 2018, all Nivalis tax credit and NOL carryforwards have been reduced to zero. We account for uncertainty in income taxes in accordance with ASC 740, Income Taxes. Tax positions are evaluated in a two-step process, whereby we first determine whether it is more likely than not that a tax position will be sustained upon examination by the tax authority, including resolutions of any related appeals or litigation processes, based on technical merit. If a tax position meets the more-likely-than-not recognition threshold it is then measured to determine the amount of benefit to recognize in the financial statements. The tax position is measured as the largest amount of benefit that is greater than 50% likely of being realized upon ultimate settlement. The following table summarizes the activity related to unrecognized tax benefits (in thousands): Years Ended December 31, 2023 2022 2021 Unrecognized benefits – beginning of year $ 2,149 $ 1,553 $ 990 Gross increases (decreases) – prior year tax positions (2) — — Gross increases – current year tax positions 727 596 563 Unrecognized benefit – end of year $ 2,874 $ 2,149 $ 1,553 All of the unrecognized tax benefits as of December 31, 2023, are accounted for as a reduction in our deferred tax assets. Due to our valuation allowance, none of the $2.9 million of unrecognized tax benefits would affect our effective tax rate, if recognized. We do not expect any significant change in our unrecognized tax benefits during the next twelve months. We recognize interest and penalties related to unrecognized tax benefits as income tax expense. There were no accrued interest or penalties related to unrecognized tax benefits for the years ended December 31, 2023, 2022, or 2021. Our material income tax jurisdictions are the United States (federal), California (state), and Australia (foreign). We are subject to audit for tax years 2012 and forward for federal purposes, 2017 and forward for California purposes, and 2019 and forward for foreign purposes. |
Related Party Transactions
Related Party Transactions | 12 Months Ended |
Dec. 31, 2023 | |
Related Party Transactions [Abstract] | |
Related Party Transactions | Related Party Transactions In February 2024, certain of our stockholders whose beneficial ownership exceeded 5%, exercised 3,200,000 prefunded warrants pursuant to a net exercise mechanism under the warrants. In January 2024, certain of our affiliates or stockholders whose beneficial ownership exceeded 5%, exercised 1,379,887 common stock warrants for proceeds of $17.6 million. In December 2023, certain of our affiliates or stockholders whose beneficial ownership exceeded 5% exercised 219,692 common stock warrants for proceeds of $1.9 million. |
401(k) Retirement Plan
401(k) Retirement Plan | 12 Months Ended |
Dec. 31, 2023 | |
Retirement Benefits [Abstract] | |
401(k) Retirement Plan | 401(k) Retirement Plan We have adopted a 401(k) defined contribution retirement savings plan. All employees are eligible to participate, provided they meet the requirements of the plan. Beginning in 2022, we started offering employer 401(k) matching contributions at our discretion subject to annually determined limits. The expense recognized related to the employer matching |
Pay vs Performance Disclosure
Pay vs Performance Disclosure - USD ($) $ in Thousands | 12 Months Ended | ||
Dec. 31, 2023 | Dec. 31, 2022 | Dec. 31, 2021 | |
Pay vs Performance Disclosure | |||
Net loss | $ (32,184) | $ (57,762) | $ (50,333) |
Insider Trading Arrangements
Insider Trading Arrangements | 3 Months Ended | 12 Months Ended |
Dec. 31, 2023 shares | Dec. 31, 2023 shares | |
Trading Arrangements, by Individual | ||
Rule 10b5-1 Arrangement Adopted | false | |
Non-Rule 10b5-1 Arrangement Adopted | false | |
Non-Rule 10b5-1 Arrangement Terminated | false | |
Mitchell H. Gold, M.D [Member] | ||
Trading Arrangements, by Individual | ||
Material Terms of Trading Arrangement | On December 28, 2023, Mitchell H. Gold, M.D., our Chief Executive Officer, terminated a Rule 10b5-1 trading arrangement providing for the sale from time to time of an aggregate of 438,000 shares of our common stock. The trading arrangement was adopted on March 30, 2023 and was intended to satisfy the affirmative defense in Rule 10b5-1(c). The duration of the trading arrangement was from June 30, 2023 until June 30, 2024, or earlier if all transactions under the trading arrangement were completed. Dr. Gold sold 213,302 shares under the trading arrangement prior to the date of termination. | |
Name | Mitchell H. Gold, M.D | |
Rule 10b5-1 Arrangement Adopted | true | |
Rule 10b5-1 Arrangement Terminated | true | |
Termination Date | December 28, 2023 | |
Aggregate Available | 438,000 | 438,000 |
Summary of Significant Accoun_2
Summary of Significant Accounting Policies (Policies) | 12 Months Ended |
Dec. 31, 2023 | |
Accounting Policies [Abstract] | |
Basis of Presentation and Use of Estimates | Basis of Presentation and Use of Estimates The accompanying consolidated financial statements have been prepared in accordance with the rules and regulations of the Securities and Exchange Commission (“SEC”) and generally accepted accounting principles in the United States of America (“GAAP”). The preparation of financial statements in conformity with GAAP requires management to make judgments, estimates and assumptions that affect the amounts reported in the consolidated financial statements and accompanying notes. Significant estimates inherent in the preparation of the accompanying consolidated financial statements include those used for revenue recognition, accruals for clinical trial activities and other accruals, the potential outcome of uncertain tax positions that have been recognized in our consolidated financial statements or tax returns, and the estimated fair value of equity-based awards. We base our estimates and assumptions on historical experience when available and on various factors we believe to be reasonable under the circumstances. Actual results could differ materially from those estimates. |
Principles of Consolidation | Principles of Consolidation Our consolidated financial statements include the financial position and results of operations of Alpine Immune Sciences, Inc. and our wholly owned operating company and subsidiary, AIS Operating Co., Inc., and our wholly owned subsidiary, Alpine Immune Sciences Australia PTY LTD. All inter-company balances and transactions have been eliminated in consolidation. |
Segments | Segments We operate as one operating segment and use cash flow as the primary financial measure to manage our business. |
Cash and Cash Equivalents and Restricted Cash | Cash and Cash Equivalents and Restricted Cash We consider all highly liquid investments with an original maturity of 90 days or less at the time of purchase to be cash equivalents. Cash and cash equivalents consist of deposits with commercial banks in checking and interest-bearing accounts, highly liquid money market funds, and U.S. Treasury bills. Restricted cash represents cash reserved under our letter of credit, which serves as a security deposit for our operating lease to rent office and laboratory space in Seattle, Washington. |
Concentration of Credit Risk | Periodically, we maintain deposits in financial institutions in excess of government insured limits. We believe we are not exposed to significant credit risk as our deposits, which are held at financial institutions, are high credit quality securities such as money market funds, U.S. Treasury bills, and commercial paper. To date, we have not realized any losses on these deposits. |
Investments | Investments Our investments include funds invested in highly liquid money market funds, U.S. Treasury bills, U.S. agency securities, non-U.S. government securities, and corporate debt securities and commercial paper with contractual maturities of less than two years. These investments are classified as available-for-sale debt securities, which are recorded at fair value based on quoted prices in active markets for Level 1 assets, and based on market pricing and other observable market inputs for similar securities for Level 2 assets. We classify our investments maturing within one year of the reporting date as short-term investments. If the estimated fair value of a debt security is below its amortized cost basis, we evaluate whether it is more likely than not that we will sell the security before its anticipated recovery in market value and whether credit losses exist for the related securities. A credit loss exists if the present value of expected cash flows is less than the amortized cost basis of the security. Credit-related losses are recognized as an allowance for credit losses on the balance sheet with a corresponding adjustment to earnings. Unrealized gains and losses that are unrelated to credit deterioration are reported in other comprehensive income (loss). Purchase premiums and discounts are recognized within interest income using the interest method over the terms of the securities. Realized gains and losses and declines in fair value for these investments deemed to be expected credit losses are reflected in our Consolidated Statements of Operations and Comprehensive Income (Loss) using the specific-identification method. |
Property and Equipment | Property and Equipment Property and equipment are stated at cost, net of accumulated depreciation. Depreciation is recorded using the straight-line method over the estimated useful lives of the assets, generally three |
Impairment of Long-lived Assets | Impairment of Long-lived Assets We evaluate our long-lived tangible assets for impairment whenever events or changes in circumstances indicate that the carrying amount of such assets may not be fully recoverable. When such events occur, we assess recoverability by comparing the asset's carrying value to the total undiscounted future cash flows the asset is expected to generate. If the carrying value exceeds the amount of undiscounted cash flows, we then measure impairment by reducing the carrying value to the assets estimated fair value. We did not record any impairments in the years ended December 31, 2023, 2022 or 2021. |
Accrued Liabilities | Accrued Liabilities As part of the process of preparing our consolidated financial statements, we are required to estimate accruals for professional services and research and development expenses. This process involves reviewing contracts and vendor agreements and communicating with applicable personnel to identify services that have been performed on our behalf. We estimate the level of service performed and the associated cost incurred for the service when we have not yet been invoiced or otherwise notified of the actual cost. We estimate accrued liabilities as of each balance sheet date based on known facts and circumstances. Although we do not expect our estimates to be materially different from amounts actually incurred, if our estimates of the status and timing of services performed differ from the actual status and timing of services performed, we may report amounts that are too high or too low in any particular period. To date, we have not experienced any significant adjustments to our estimates. |
Leases | Leases |
Derivative Financial Instruments | Derivative Financial Instruments We evaluate all of our financial instruments, including prefunded warrants and warrants to purchase common stock, to determine if such instruments are derivatives or contain features qualifying as embedded derivatives. For derivative financial instruments accounted for as liabilities, the derivative instrument is initially recorded at its fair value and is then re-valued at each reporting date, with changes in the fair value reported in the Consolidated Statements of Operations and Comprehensive Income (Loss) . We use the Black-Scholes option-pricing model to value the derivative instruments at inception and subsequent valuation dates. The classification of derivative instruments, including whether such instruments should be recorded as liabilities or as equity, is reassessed at the end of each reporting period. We do not use derivative instruments to hedge exposures to cash flow, market or foreign currency risks. |
Revenue Recognition | Revenue Recognition Revenue is recognized when control of the promised goods or services is transferred to our customers, in an amount that reflects the consideration we expect to be entitled to in exchange for those goods or services. Our steps for recognizing revenue consist of (1) identifying the contract; (2) identifying the performance obligations as either distinct or bundled goods and services; (3) determining the transaction price associated with each performance obligation for which we expect to be entitled in exchange for transferring such goods and services; (4) allocating the transaction price to the performance obligations in the contract; and (5) recognizing revenue upon satisfaction of performance obligations. Our collaboration agreements principally contain multiple performance obligations, which may include (1) grants of, or options to obtain, intellectual property licenses; (2) research and development services; and/or (3) manufacturing or supply services. Payments received under these arrangements typically include one or more of the following: non-refundable upfront license fees, option exercise fees, payment for research and/or development efforts, amounts due upon the achievement of specified objectives, and/or royalties on future product sales. Our revenue is primarily derived from our collaboration agreements with Adaptimmune Therapeutics plc (“Adaptimmune”), AbbVie Ireland Unlimited Company (“AbbVie”), and Horizon Therapeutics Ireland DAC (acquired by Amgen Inc., or “Amgen,” in October 2023). See further discussion of our collaboration agreements in Note 10 . We allocate revenue to each performance obligation based on its relative stand-alone selling price. We generally determine stand-alone selling prices at the inception of the contract based on our best estimate of what the selling price would be if the deliverable was regularly sold by us on a stand-alone basis. Payments received prior to satisfying the relevant revenue recognition criteria are recorded as deferred revenue in the accompanying Consolidated Balance Sheets and recognized as revenue when the related revenue recognition criteria are met. We recognize revenue under our collaboration agreements by using a cost-based input method to measure progress toward completion of the performance obligation, including employee hours contributed to each performance obligation, and to calculate the corresponding revenue to recognize each period. Our collaboration agreements provide for non-refundable milestone payments. We recognize revenue that is contingent upon the achievement of a substantive milestone in its entirety in the period in which the milestone is achieved. A milestone is considered substantive when the consideration payable to us for such milestone (1) is consistent with our performance necessary to achieve the milestone or the increase in value to the collaboration resulting from our performance; (2) relates solely to our past performance; and (3) is reasonable relative to all of the other deliverables and payments within the arrangement. In making this assessment, we consider all facts and circumstances relevant to the arrangement, including factors such as the scientific, regulatory, commercial, and other risks that must be overcome to achieve the milestone, the level of effort and investment required to achieve the milestone and whether any portion of the milestone consideration is related to future performance or deliverables. We review the contributed employee hours and progress towards completion for each performance obligation under our collaboration agreements, and adjust the revenue recognized to reflect changes in assumptions relating to the estimated satisfaction of the performance obligation. Revenue recognition may be accelerated in the event of early termination of programs or if our expectations change. Alternatively, revenue recognition may be decelerated if programs are extended or delayed. While such changes to our estimates have no impact on our reported cash flows, the timing of revenue recorded in future periods could be materially impacted. |
Research and Development | Research and Development Research and development costs are expensed as incurred. Research and development costs include personnel costs, clinical trials, external contract research and development expenses, raw materials, drug product manufacturing costs and allocated overhead – including depreciation, rent and utilities. Research and development costs that are paid in advance of performance are capitalized as a prepaid expense and amortized over the service period as the services are provided. |
Stock-based Compensation | Stock-based Compensation Stock-based compensation is recognized for all share-based payments based on the estimated fair value as of the date of grant. The fair value of our stock options is calculated using the Black-Scholes option pricing model, which requires judgmental assumptions including volatility, risk-free interest rate, expected term and dividend yield. The fair value of restricted stock units (“RSUs”) is based on the closing price of our common stock on the award date. Stock-based compensation expense is recognized over the requisite service period of the awards, usually the vesting period, on a straight-line basis. For performance-based awards where the vesting of the options may be accelerated upon the achievement of certain milestones, the related stock-based compensation is recognized as expense when it is probable the milestone will be met. We recognize forfeiture of awards as they occur rather than estimating the expected forfeiture rate. |
Income Taxes | Income Taxes Income taxes are accounted for using an asset and liability approach that requires the recognition of deferred tax assets and liabilities for the expected future tax consequences of temporary differences between the consolidated financial statement and tax bases of assets and liabilities at the applicable enacted tax rates. We establish a valuation allowance for deferred tax assets if it is more likely than not that these items will expire before we are able to realize their benefits or that future deductibility is uncertain. |
Comprehensive Income (Loss) | Comprehensive Income (Loss) Comprehensive income (loss) is comprised of net loss and certain changes in equity excluded from net loss. For the years ended December 31, 2023, 2022 and 2021, comprehensive income (loss) consisted of unrealized gains and losses on our investments and unrealized gains and losses on foreign currency translation. |
Foreign Currency Translation | Foreign Currency Translation Our wholly-owned Australian subsidiary uses the Australian dollar as its functional currency. All assets and liabilities related to this subsidiary are translated using period-end exchange rates, and revenues and expenses are translated at average exchange rates for the year. Translation adjustments are included as components of comprehensive income (loss) in the Consolidated Statements of Operations and Comprehensive Income (Loss) . |
Net Loss Per Share | Net Loss Per ShareBasic net loss per share is computed by dividing net loss by the weighted-average number of common shares outstanding during the period. |
Fair Value Measurements | Fair Value Measurements Cash and cash equivalents, restricted cash, receivables, accounts payable and accrued liabilities, which are recorded at invoiced amount or cost, approximate fair value based on the short-term nature of these financial instruments. Fair value is defined as the exchange price received for an asset or paid to transfer a liability, or an exit price, in the principal or most advantageous market for the asset or liability in an orderly transaction between market participants on the measurement date. Valuation techniques used to measure fair value must maximize the use of observable inputs and minimize the use of unobservable inputs. The three-tier fair value hierarchy, which prioritizes the inputs used in measuring fair value, is as follows: Level 1 : Quoted prices in active markets for identical assets or liabilities. Level 2 : Observable inputs other than Level 1 prices, such as quoted prices for similar assets or liabilities, quoted prices in inactive markets, 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 supported by little or no market activity and significant to the fair value of the assets or liabilities. |
Recently Issued Accounting Pronouncements | Recently Issued Accounting Pronouncements In December 2023, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update ("ASU”) 2023-09, Income Taxes (Topic 740): Improvements to Income Tax Disclosures , which requires public entities to disclose disaggregated information about their effective tax rate reconciliation as well as expanded information on income taxes paid by jurisdiction. The disclosure requirements will be applied on a prospective basis, with the option to apply them retrospectively. The standard is effective for annual periods beginning after December 15, 2024, with early adoption permitted. We plan to adopt this guidance for the fiscal year ending December 31, 2025. We are currently evaluating the impact of this new guidance on our disclosure requirements related to the new standard, but do not expect it to have a material impact on our financial condition, results of operations, or cash flows. In November 2023, the FASB issued ASU 2023-07, Segment Reporting (Topic 280): Improvements to Reportable Segment Disclosures , which requires enhanced segment disclosures. Public entities with a single reporting segment are required to provide all disclosures required by Topic 280. This standard is effective for fiscal years beginning after December 15, 2023, and interim periods within fiscal years beginning after December 15, 2024, with early adoption permitted. The enhanced disclosures are required to be applied retrospectively to all prior periods presented in the financial statements. We plan to adopt this guidance for the fiscal year ending December 31, 2024. We are currently evaluating the impact of this new guidance on our disclosure requirements related to the new standard, but do not expect it to have a material impact on our financial condition, results of operations, or cash flows. |
Net Loss Per Share (Tables)
Net Loss Per Share (Tables) | 12 Months Ended |
Dec. 31, 2023 | |
Earnings Per Share [Abstract] | |
Schedule of Anti-dilutive Securities Excluded from Diluted Net Loss Per Share Attributable to Common Stockholders | The common stock issuable upon the conversion or exercise of the following dilutive securities has been excluded from the diluted net loss per share calculation because their effect would have been anti-dilutive. Diluted net loss per share, therefore, is the same as basic net loss per share for the periods presented. December 31, 2023 2022 2021 Common stock warrants 2,369,351 3,656,497 3,666,435 Prefunded warrants to purchase common stock 6,102,127 5,182,197 5,182,197 Stock options and RSUs outstanding 8,013,824 7,236,758 5,877,309 Total 16,485,302 16,075,452 14,725,941 |
Cash Equivalents and Investme_2
Cash Equivalents and Investments (Tables) | 12 Months Ended |
Dec. 31, 2023 | |
Cash, Cash Equivalents, and Short-Term Investments [Abstract] | |
Schedule of Amortized Cost and Fair Value of Cash Equivalents and Investments | The amortized cost and fair value of our cash equivalents and investments are as follows (in thousands): December 31, 2023 Amortized Cost Gross unrealized gains Gross unrealized losses Fair market value Money market funds $ 31,530 $ — $ — $ 31,530 U.S. treasury bills 217,857 377 (47) 218,187 U.S. agency securities 30,412 14 (57) 30,369 Corporate debt securities and commercial paper 84,425 91 (24) 84,492 Total $ 364,224 $ 482 $ (128) $ 364,578 Classified as: Cash equivalents $ 40,531 Short-term investments 283,491 Long-term investments 40,556 Total $ 364,578 December 31, 2022 Amortized Cost Gross unrealized gains Gross unrealized losses Fair market value Money market funds $ 11,004 $ — $ — $ 11,004 U.S. treasury bills 113,964 5 (721) 113,248 U.S. agency securities 10,921 5 (11) 10,915 Non-U.S. government securities 6,060 — (22) 6,038 Corporate debt securities and commercial paper 129,940 4 (399) 129,545 Total $ 271,889 $ 14 $ (1,153) $ 270,750 Classified as: Cash equivalents $ 11,004 Short-term investments 224,265 Long-term investments 35,481 Total $ 270,750 |
Schedule of Debt Securities, Available-for-Sale, Unrealized Loss Position, Fair Value | For investments in an unrealized loss position as of the respective balance sheet dates, the following table summarizes the fair value and gross unrealized losses by category, disaggregated by the length of time that individual debt securities have been in a continuous unrealized loss position (in thousands): December 31, 2023 Less Than 12 Months 12 Months or Greater Total Fair Value Unrealized Losses Fair Value Unrealized Losses Fair Value Unrealized Losses U.S. treasury bills $ 12,779 $ (25) $ 6,994 $ (22) $ 19,773 $ (47) U.S. agency securities 26,248 (57) — — 26,248 (57) Corporate debt securities and commercial paper 27,477 (24) — — 27,477 (24) Total $ 66,504 $ (106) $ 6,994 $ (22) $ 73,498 $ (128) December 31, 2022 Less Than 12 Months 12 Months or Greater Total Fair Value Unrealized Losses Fair Value Unrealized Losses Fair Value Unrealized Losses U.S. treasury bills $ 82,694 $ (368) $ 17,648 $ (353) $ 100,342 $ (721) U.S. agency securities 7,552 (11) — — 7,552 (11) Non-U.S. government securities 3,012 (16) 3,026 (6) 6,038 (22) Corporate debt securities and commercial paper 27,839 (195) 22,171 (204) 50,010 (399) Total $ 121,097 $ (590) $ 42,845 $ (563) $ 163,942 $ (1,153) |
Fair Value Measurements (Tables
Fair Value Measurements (Tables) | 12 Months Ended |
Dec. 31, 2023 | |
Fair Value Disclosures [Abstract] | |
Schedule of Financial Assets and Liabilities Measured at Fair Value on Recurring Basis | We had no financial liabilities measured at fair value for the periods presented and the following tables summarize our financial assets measured at fair value on a recurring basis (in thousands): Assets: December 31, 2023 Level 1 Level 2 Level 3 Total Money market funds $ 31,530 $ — $ — $ 31,530 U.S. treasury bills 218,187 — — 218,187 U.S. agency securities — 30,369 — 30,369 Corporate debt securities and commercial paper — 84,492 — 84,492 Total $ 249,717 $ 114,861 $ — $ 364,578 Assets: December 31, 2022 Level 1 Level 2 Level 3 Total Money market funds $ 11,004 $ — $ — $ 11,004 U.S. treasury bills 113,248 — — 113,248 U.S. agency securities — 10,915 — 10,915 Non-U.S. government securities — 6,038 — 6,038 Corporate debt securities and commercial paper — 129,545 — 129,545 Total $ 124,252 $ 146,498 $ — $ 270,750 |
Property and Equipment (Tables)
Property and Equipment (Tables) | 12 Months Ended |
Dec. 31, 2023 | |
Property, Plant and Equipment [Abstract] | |
Schedule of Property and Equipment | Property and equipment, net, consists of the following (in thousands): December 31, 2023 2022 Laboratory equipment $ 3,472 $ 3,191 General equipment and furniture 459 459 Computer equipment and software 268 217 Leasehold improvements 118 118 Property and equipment, at cost 4,317 3,985 Less accumulated depreciation and amortization (2,833) (2,401) Property and equipment, net $ 1,484 $ 1,584 |
Additional Balance Sheet Info_2
Additional Balance Sheet Information (Tables) | 12 Months Ended |
Dec. 31, 2023 | |
Organization, Consolidation and Presentation of Financial Statements [Abstract] | |
Schedule of Prepaid Expenses and Other Current Assets | Prepaid expenses and other current assets consist of the following (in thousands): December 31, 2023 2022 Prepaid research and development $ 1,025 $ 1,881 Prepaid insurance 521 368 Prepaid other 327 394 Other receivables 582 317 Prepaid expenses and other current assets $ 2,455 $ 2,960 |
Schedule of Accrued Liabilities Disclosure | Accrued liabilities consist of the following (in thousands): December 31, 2023 2022 Research and development services $ 12,838 $ 7,657 Employee compensation 7,970 4,110 Legal and professional fees 283 334 Accrued taxes 4 1,847 Accrued other 92 55 Accrued liabilities $ 21,187 $ 14,003 |
Commitments and Contingencies (
Commitments and Contingencies (Tables) | 12 Months Ended |
Dec. 31, 2023 | |
Commitments and Contingencies Disclosure [Abstract] | |
Schedule of Components of Lease Cost | Supplemental operating lease information is as follows (in thousands): Years Ended December 31, 2023 2022 2021 Operating lease cost $ 1,843 $ 1,839 $ 1,837 Variable lease cost 917 823 603 Total lease cost $ 2,760 $ 2,662 $ 2,440 Other information: Cash paid for amounts included in the measurement of lease liabilities $ 2,062 $ 2,009 $ 2,117 Weighted-average remaining lease term (years) 6.2 7.2 8.2 Weighted-average discount rate 10.7% 10.7% 10.7% |
Schedule of Future Minimum Lease Payments for Non-cancelable Operating Leases | Maturities of our operating lease liabilities as of December 31, 2023, are as follows (in thousands): Minimum Lease Payments 2024 $ 1,939 2025 2,167 2026 2,224 2027 2,283 2028 2,344 Thereafter 2,811 Total future minimum lease payments 13,768 Less: imputed interest (3,854) Operating lease liabilities $ 9,914 |
License and Collaboration Agr_2
License and Collaboration Agreements (Tables) | 12 Months Ended |
Dec. 31, 2023 | |
Organization, Consolidation and Presentation of Financial Statements [Abstract] | |
Schedule of Contract Balances | Respective balances are as follows (in thousands): December 31, 2023 2022 Contract Assets $ 167 $ 392 Contract Liabilities $ 17,217 $ 74,756 |
Schedule of Disaggregation of Revenue | Collaboration revenue recognized in our accompanying Consolidated Statements of Operations and Comprehensive Income (Loss) , disaggregated by customer, is as follows (in thousands): Years Ended December 31, 2023 2022 2021 AbbVie $ 41,925 $ 17,064 $ 23,443 Amgen 16,487 11,964 — Adaptimmune 464 1,036 — Total collaboration revenue $ 58,876 $ 30,064 $ 23,443 |
Stockholders' Equity (Tables)
Stockholders' Equity (Tables) | 12 Months Ended |
Dec. 31, 2023 | |
Equity [Abstract] | |
Schedule of Shares of Common Stock Reserved for Future Issuance | Shares of common stock reserved for future issuance were as follows: December 31, 2023 2022 Shares to be issued upon exercise of outstanding stock options 7,968,360 7,058,140 Shares to be issued upon release of RSUs 45,464 178,618 Shares to be issued upon conversion of common stock warrants 2,369,351 3,656,497 Shares to be issued upon conversion of prefunded warrants 6,102,127 5,182,197 Shares available for future stock grants 281,984 314,523 Shares to be issued under employee stock purchase plan 45,211 45,211 Shares of common stock reserved for future issuance 16,812,497 16,435,186 |
Schedule of Stockholders' Equity Note, Warrants or Rights | Excluding the prefunded warrants we issued in connection with our securities offerings discussed above, the table below summarizes our common stock warrant activity: Warrants Weighted- Weighted- Outstanding at December 31, 2022 3,656,497 $ 12.66 1.12 Exercised (1,287,146) 12.74 Outstanding and Exercisable at December 31, 2023 2,369,351 $ 12.62 0.15 |
Schedule of Stock Option Activity | A summary of stock option activity under our plans is presented below: Options Weighted- Weighted- Aggregate Outstanding at December 31, 2022 7,058,140 $ 8.37 Granted 2,816,197 $ 9.50 Exercised (858,511) $ 5.91 Forfeited (1,047,466) $ 10.40 Outstanding at December 31, 2023 7,968,360 $ 8.77 6.96 $ 82,254 Vested and expected to vest after December 31, 2023 7,790,360 $ 8.79 6.95 $ 80,307 Exercisable at December 31, 2023 4,462,145 $ 7.79 5.62 $ 50,542 |
Schedule of RSU Activity | A summary of our RSU activity under our plans is presented below: Number of Shares Weighted- Weighted- Aggregate Non-vested at December 31, 2022 178,618 $ 12.00 Vested (114,651) $ 12.00 Forfeited (18,503) $ 12.00 Non-vested at December 31, 2023 45,464 $ 12.00 0.0 $ 867 |
Schedule of Stock Option Assumptions | The fair values of stock options granted to employees were calculated using the following assumptions: Years Ended December 31, 2023 2022 2021 Weighted-average estimated fair value at grant $6.94 $7.56 $8.44 Risk-free interest rate (1) 3.36% - 4.67% 1.39% - 4.04% 0.25% - 1.3% Expected term of options (in years) (2) 5.27 - 6.08 5.27 – 6.08 3.49 – 6.08 Expected stock price volatility (3) 81% - 85% 80% - 83% 79% - 83% Expected dividend yield (4) —% —% —% (1) The risk-free interest rate assumption was based on zero-coupon U.S. Treasury instruments that had terms consistent with the expected term of our stock option grants. (2) We used the “simplified method” for options to determine the expected term of stock options granted, since we do not have sufficient historical exercise data to provide a reasonable basis upon which to estimate expected term due to the limited time our shares have been publicly traded. Under this approach, the weighted-average expected life is presumed to be the average of the vesting term and the contractual term of the option. (3) Volatility is a measure of the amount by which a financial variable, such as share price, has fluctuated or is expected to fluctuate during a period. We analyzed the historical stock price volatility of companies at a similar stage of development to estimate the expected volatility of our stock price. (4) We have never declared or paid any cash dividends and do not presently plan to pay cash dividends in the foreseeable future. |
Schedule of Stock-based Compensation Expense | Stock-based compensation expense is classified in the Consolidated Statements of Operations and Comprehensive Income (Loss) as follows (in thousands): Years Ended December 31, 2023 2022 2021 Research and development $ 6,251 $ 5,713 $ 3,347 General and administrative 4,379 3,935 2,893 Total stock-based compensation expense $ 10,630 $ 9,648 $ 6,240 |
Income Taxes (Tables)
Income Taxes (Tables) | 12 Months Ended |
Dec. 31, 2023 | |
Income Tax Disclosure [Abstract] | |
Schedule of Loss Before Taxes, Domestic and Foreign | Our loss before taxes is derived from domestic (United States) and foreign (Australian) sources as follows (in thousands): Years Ended December 31, 2023 2022 2021 Domestic $ (32,450) $ (55,475) $ (48,932) Foreign 369 43 (1,488) Total $ (32,081) $ (55,432) $ (50,420) |
Schedule of Provision for Income Taxes | The provision for income taxes is composed of the following (in thousands): Years Ended December 31, 2023 2022 2021 Current: U.S. - Federal $ 47 $ (981) $ — U.S. - State 4 (16) — Foreign — (1,285) (129) Total current 51 (2,282) (129) Deferred: Foreign (154) (48) 216 Total deferred (154) (48) 216 Total income tax (expense) benefit $ (103) $ (2,330) $ 87 |
Schedule of Effective Tax Rate of Provision for Income Taxes Differs from Federal Statutory Rate | The effective tax rate of the provision for income taxes differs from the federal statutory rate as follows: Years Ended December 31, 2023 2022 2021 U.S. Statutory rate 21.0 % 21.0 % 21.0 % Effect of: State taxes (net of federal benefit) 0.3 % 0.1 % — % Permanent differences 0.3 % — % (0.4) % Federal research and development credit 9.2 % 5.0 % 4.5 % Change in valuation allowance (29.1) % (28.6) % (21.4) % Global intangible low-taxed income recapture — % (0.6) % (1.4) % Stock-based compensation (1.6) % (1.9) % (1.8) % Foreign rate differential (0.1) % — % 0.2 % Other (0.3) % — % (0.5) % Voluntary disclosure net change in prior years’ tax liabilities — % 0.8 % — % Effective income tax rate (0.3) % (4.2) % 0.2 % |
Schedule of Significant Components of Deferred Tax Assets and Liabilities | The following table represents the significant components of our deferred tax assets and liabilities for the periods presented (in thousands): December 31, 2023 2022 Deferred tax assets: Net operating loss $ 23,205 $ 18,590 Research and development credits 9,259 6,240 Intangible asset basis 4 2 Lease liability 2,126 2,315 Deferred revenue 3,600 14,752 Stock based compensation 2,428 2,343 Capitalized research and experimental costs 24,147 12,681 Other 1,088 156 Gross deferred tax assets 65,857 57,079 Valuation allowance (63,897) (54,841) Total deferred tax assets, net of valuation allowance 1,960 2,238 Deferred tax liabilities: Prepaid expenses (251) (173) Fixed asset basis (126) (182) Right-of-use asset basis (1,583) (1,728) Total deferred tax liability (1,960) (2,083) Net deferred tax assets and liabilities $ — $ 155 |
Schedule of Net Operating Loss Carryforwards | We have net operating loss (“NOL”) carryforwards as follows (in thousands): December 31, 2023 2022 Federal (after January 1, 2018) $ 108,393 $ 85,012 State $ 6,778 $ 6,433 |
Schedule of Net Research and Development Tax Credit Carryforwards | We have net research and development tax credit carryforwards as follows (in thousands): December 31, 2023 2022 Federal $ 11,584 $ 7,892 Foreign $ 578 $ 527 |
Schedule of Activity Related to Unrecognized Tax benefits | The following table summarizes the activity related to unrecognized tax benefits (in thousands): Years Ended December 31, 2023 2022 2021 Unrecognized benefits – beginning of year $ 2,149 $ 1,553 $ 990 Gross increases (decreases) – prior year tax positions (2) — — Gross increases – current year tax positions 727 596 563 Unrecognized benefit – end of year $ 2,874 $ 2,149 $ 1,553 |
Summary of Significant Accoun_3
Summary of Significant Accounting Policies (Details) - segment | 12 Months Ended | |
Dec. 31, 2023 | Dec. 31, 2022 | |
Summary Of Significant Accounting Policies [Line Items] | ||
Number of operating segments | 1 | |
Debt securities, available-for-sale, term (less than) (in years) | 2 years | 2 years |
Minimum percentage of income tax benefit realized upon ultimate settlement (greater than) (as a percent) | 50% | |
Minimum | ||
Summary Of Significant Accounting Policies [Line Items] | ||
Estimated useful lives of the assets (in years) | 3 years | |
Maximum | ||
Summary Of Significant Accounting Policies [Line Items] | ||
Estimated useful lives of the assets (in years) | 5 years |
Net Loss Per Share - Narrative
Net Loss Per Share - Narrative (Details) - shares | 1 Months Ended | 12 Months Ended | ||||||
Nov. 30, 2023 | Jun. 30, 2023 | Sep. 30, 2022 | Dec. 31, 2021 | Sep. 30, 2021 | Dec. 31, 2023 | Dec. 31, 2022 | Dec. 31, 2021 | |
Common Stock | ||||||||
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] | ||||||||
Stock issued (in shares) | 9,791,832 | 919,413 | 15,509,282 | 9,791,832 | 15,509,282 | 6,489,357 | ||
Exercise of warrants, net of shares withheld (in shares) | 2,711,389 | |||||||
2021 PIPE | ||||||||
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] | ||||||||
Stock issued (in shares) | 6,489,357 | |||||||
Amgen | ||||||||
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] | ||||||||
Stock issued (in shares) | 951,980 |
Net Loss Per Share - Schedule o
Net Loss Per Share - Schedule of Anti-dilutive Securities Excluded from Diluted Net Loss Per Share Attributable to Common Stockholders Calculation (Details) - shares | 12 Months Ended | ||
Dec. 31, 2023 | Dec. 31, 2022 | Dec. 31, 2021 | |
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] | |||
Antidilutive securities excluded from computation of earnings per share (in shares) | 16,485,302 | 16,075,452 | 14,725,941 |
Common stock warrants | |||
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] | |||
Antidilutive securities excluded from computation of earnings per share (in shares) | 2,369,351 | 3,656,497 | 3,666,435 |
Prefunded warrants to purchase common stock | |||
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] | |||
Antidilutive securities excluded from computation of earnings per share (in shares) | 6,102,127 | 5,182,197 | 5,182,197 |
Stock options and RSUs outstanding | |||
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] | |||
Antidilutive securities excluded from computation of earnings per share (in shares) | 8,013,824 | 7,236,758 | 5,877,309 |
Cash Equivalents and Investme_3
Cash Equivalents and Investments - Amortized Cost and Fair Value of Cash Equivalents and Short Term Investments (Details) - USD ($) $ in Thousands | Dec. 31, 2023 | Dec. 31, 2022 |
Debt Securities, Available-for-sale [Line Items] | ||
Amortized Cost | $ 364,224 | $ 271,889 |
Gross unrealized gains | 482 | 14 |
Gross unrealized losses | (128) | (1,153) |
Fair market value | 364,578 | 270,750 |
Cash equivalents | ||
Debt Securities, Available-for-sale [Line Items] | ||
Fair market value | 40,531 | 11,004 |
Short-term investments | ||
Debt Securities, Available-for-sale [Line Items] | ||
Fair market value | 283,491 | 224,265 |
Long-term investments | ||
Debt Securities, Available-for-sale [Line Items] | ||
Fair market value | 40,556 | 35,481 |
Money market funds | ||
Debt Securities, Available-for-sale [Line Items] | ||
Amortized Cost | 31,530 | 11,004 |
Gross unrealized gains | 0 | 0 |
Gross unrealized losses | 0 | 0 |
Fair market value | 31,530 | 11,004 |
U.S. treasury bills | ||
Debt Securities, Available-for-sale [Line Items] | ||
Amortized Cost | 217,857 | 113,964 |
Gross unrealized gains | 377 | 5 |
Gross unrealized losses | (47) | (721) |
Fair market value | 218,187 | 113,248 |
U.S. agency securities | ||
Debt Securities, Available-for-sale [Line Items] | ||
Amortized Cost | 30,412 | 10,921 |
Gross unrealized gains | 14 | 5 |
Gross unrealized losses | (57) | (11) |
Fair market value | 30,369 | 10,915 |
Non-U.S. government securities | ||
Debt Securities, Available-for-sale [Line Items] | ||
Amortized Cost | 6,060 | |
Gross unrealized gains | 0 | |
Gross unrealized losses | (22) | |
Fair market value | 6,038 | |
Corporate debt securities and commercial paper | ||
Debt Securities, Available-for-sale [Line Items] | ||
Amortized Cost | 84,425 | 129,940 |
Gross unrealized gains | 91 | 4 |
Gross unrealized losses | (24) | (399) |
Fair market value | $ 84,492 | $ 129,545 |
Cash Equivalents and Investme_4
Cash Equivalents and Investments - Narrative (Details) - USD ($) $ in Thousands | 12 Months Ended | ||
Dec. 31, 2023 | Dec. 31, 2022 | Dec. 31, 2021 | |
Cash, Cash Equivalents, and Short-Term Investments [Abstract] | |||
Debt securities, available-for-sale, term (less than) (in years) | 2 years | 2 years | |
Realized gains on investments | $ 33 | $ 0 | $ 0 |
Realized losses on securities | $ 0 | $ 0 | $ 0 |
Cash Equivalents and Investme_5
Cash Equivalents and Investments - Schedule of Debt Securities, Available-for-Sale, Unrealized Loss Position, Fair Value (Details) - USD ($) $ in Thousands | Dec. 31, 2023 | Dec. 31, 2022 |
Debt Securities, Available-for-Sale, Unrealized Loss Position [Line Items] | ||
Debt securities, less than 12 months, fair value | $ 66,504 | $ 121,097 |
Debt securities, less than 12 months, unrealized losses | (106) | (590) |
Debt securities, 12 months or greater, fair value | 6,994 | 42,845 |
Debt securities, 12 months or greater, unrealized losses | (22) | (563) |
Debt securities, total, fair value | 73,498 | 163,942 |
Debt securities, total, unrealized losses | (128) | (1,153) |
U.S. treasury bills | ||
Debt Securities, Available-for-Sale, Unrealized Loss Position [Line Items] | ||
Debt securities, less than 12 months, fair value | 12,779 | 82,694 |
Debt securities, less than 12 months, unrealized losses | (25) | (368) |
Debt securities, 12 months or greater, fair value | 6,994 | 17,648 |
Debt securities, 12 months or greater, unrealized losses | (22) | (353) |
Debt securities, total, fair value | 19,773 | 100,342 |
Debt securities, total, unrealized losses | (47) | (721) |
U.S. agency securities | ||
Debt Securities, Available-for-Sale, Unrealized Loss Position [Line Items] | ||
Debt securities, less than 12 months, fair value | 26,248 | 7,552 |
Debt securities, less than 12 months, unrealized losses | (57) | (11) |
Debt securities, 12 months or greater, fair value | 0 | 0 |
Debt securities, 12 months or greater, unrealized losses | 0 | 0 |
Debt securities, total, fair value | 26,248 | 7,552 |
Debt securities, total, unrealized losses | (57) | (11) |
Non-U.S. government securities | ||
Debt Securities, Available-for-Sale, Unrealized Loss Position [Line Items] | ||
Debt securities, less than 12 months, fair value | 3,012 | |
Debt securities, less than 12 months, unrealized losses | (16) | |
Debt securities, 12 months or greater, fair value | 3,026 | |
Debt securities, 12 months or greater, unrealized losses | (6) | |
Debt securities, total, fair value | 6,038 | |
Debt securities, total, unrealized losses | (22) | |
Corporate debt securities and commercial paper | ||
Debt Securities, Available-for-Sale, Unrealized Loss Position [Line Items] | ||
Debt securities, less than 12 months, fair value | 27,477 | 27,839 |
Debt securities, less than 12 months, unrealized losses | (24) | (195) |
Debt securities, 12 months or greater, fair value | 0 | 22,171 |
Debt securities, 12 months or greater, unrealized losses | 0 | (204) |
Debt securities, total, fair value | 27,477 | 50,010 |
Debt securities, total, unrealized losses | $ (24) | $ (399) |
Fair Value Measurements - Narra
Fair Value Measurements - Narrative (Details) - USD ($) $ in Millions | Dec. 31, 2023 | Dec. 31, 2022 |
Fair Value Disclosures [Abstract] | ||
Cash | $ 3.4 | $ 2.4 |
Fair Value Measurements - Summa
Fair Value Measurements - Summary of Financial Assets and Liabilities Measured at Fair Value on Recurring Basis (Details) - USD ($) $ in Thousands | Dec. 31, 2023 | Dec. 31, 2022 |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ||
Fair value assets disclosure | $ 364,578 | $ 270,750 |
Money market funds | ||
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ||
Fair value assets disclosure | 31,530 | 11,004 |
U.S. treasury bills | ||
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ||
Fair value assets disclosure | 218,187 | 113,248 |
U.S. agency securities | ||
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ||
Fair value assets disclosure | 30,369 | 10,915 |
Non-U.S. government securities | ||
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ||
Fair value assets disclosure | 6,038 | |
Corporate debt securities and commercial paper | ||
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ||
Fair value assets disclosure | 84,492 | 129,545 |
Level 1 | ||
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ||
Fair value assets disclosure | 249,717 | 124,252 |
Level 1 | Money market funds | ||
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ||
Fair value assets disclosure | 31,530 | 11,004 |
Level 1 | U.S. treasury bills | ||
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ||
Fair value assets disclosure | 218,187 | 113,248 |
Level 1 | U.S. agency securities | ||
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ||
Fair value assets disclosure | 0 | 0 |
Level 1 | Non-U.S. government securities | ||
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ||
Fair value assets disclosure | 0 | |
Level 1 | Corporate debt securities and commercial paper | ||
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ||
Fair value assets disclosure | 0 | 0 |
Level 2 | ||
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ||
Fair value assets disclosure | 114,861 | 146,498 |
Level 2 | Money market funds | ||
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ||
Fair value assets disclosure | 0 | 0 |
Level 2 | U.S. treasury bills | ||
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ||
Fair value assets disclosure | 0 | 0 |
Level 2 | U.S. agency securities | ||
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ||
Fair value assets disclosure | 30,369 | 10,915 |
Level 2 | Non-U.S. government securities | ||
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ||
Fair value assets disclosure | 6,038 | |
Level 2 | Corporate debt securities and commercial paper | ||
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ||
Fair value assets disclosure | 84,492 | 129,545 |
Level 3 | ||
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ||
Fair value assets disclosure | 0 | 0 |
Level 3 | Money market funds | ||
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ||
Fair value assets disclosure | 0 | 0 |
Level 3 | U.S. treasury bills | ||
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ||
Fair value assets disclosure | 0 | 0 |
Level 3 | U.S. agency securities | ||
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ||
Fair value assets disclosure | 0 | 0 |
Level 3 | Non-U.S. government securities | ||
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ||
Fair value assets disclosure | 0 | |
Level 3 | Corporate debt securities and commercial paper | ||
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ||
Fair value assets disclosure | $ 0 | $ 0 |
Property and Equipment - Schedu
Property and Equipment - Schedule of Property and Equipment (Details) - USD ($) $ in Thousands | Dec. 31, 2023 | Dec. 31, 2022 |
Property, Plant and Equipment, Gross [Abstract] | ||
Property and equipment, at cost | $ 4,317 | $ 3,985 |
Less accumulated depreciation and amortization | (2,833) | (2,401) |
Property and equipment, net | 1,484 | 1,584 |
Laboratory equipment | ||
Property, Plant and Equipment, Gross [Abstract] | ||
Property and equipment, at cost | 3,472 | 3,191 |
General equipment and furniture | ||
Property, Plant and Equipment, Gross [Abstract] | ||
Property and equipment, at cost | 459 | 459 |
Computer equipment and software | ||
Property, Plant and Equipment, Gross [Abstract] | ||
Property and equipment, at cost | 268 | 217 |
Leasehold improvements | ||
Property, Plant and Equipment, Gross [Abstract] | ||
Property and equipment, at cost | $ 118 | $ 118 |
Property and Equipment - Narrat
Property and Equipment - Narrative (Details) - USD ($) $ in Thousands | 12 Months Ended | ||
Dec. 31, 2023 | Dec. 31, 2022 | Dec. 31, 2021 | |
Property, Plant and Equipment [Abstract] | |||
Depreciation expense | $ 576 | $ 597 | $ 620 |
Additional Balance Sheet Info_3
Additional Balance Sheet Information - Prepaid Expense and Other Current Assets (Details) - USD ($) $ in Thousands | Dec. 31, 2023 | Dec. 31, 2022 |
Organization, Consolidation and Presentation of Financial Statements [Abstract] | ||
Prepaid research and development | $ 1,025 | $ 1,881 |
Prepaid insurance | 521 | 368 |
Prepaid other | 327 | 394 |
Other receivables | 582 | 317 |
Prepaid expenses and other current assets | $ 2,455 | $ 2,960 |
Additional Balance Sheet Info_4
Additional Balance Sheet Information - Accrued Liabilities (Details) - USD ($) $ in Thousands | Dec. 31, 2023 | Dec. 31, 2022 |
Organization, Consolidation and Presentation of Financial Statements [Abstract] | ||
Research and development services | $ 12,838 | $ 7,657 |
Employee compensation | 7,970 | 4,110 |
Legal and professional fees | 283 | 334 |
Accrued taxes | 4 | 1,847 |
Accrued other | 92 | 55 |
Accrued liabilities | $ 21,187 | $ 14,003 |
Long-term Debt (Details)
Long-term Debt (Details) | 1 Months Ended | |||||
Mar. 31, 2020 USD ($) | Aug. 31, 2019 USD ($) tranche $ / shares shares | Dec. 31, 2023 USD ($) | May 31, 2023 USD ($) | Jul. 31, 2020 USD ($) | Mar. 30, 2020 USD ($) shares | |
SVB Term Loan | ||||||
Debt Instrument [Line Items] | ||||||
Long-term debt, gross | $ 0 | $ 1,400,000 | ||||
Debt instrument, face amount | 800,000 | |||||
Prepayment fee | $ 625,000 | |||||
Term Loans | Term Loans, Tranche One | Common Stock Warrant | ||||||
Debt Instrument [Line Items] | ||||||
Fair value of warrant liability | $ 60,000 | |||||
Term Loans | Term Loans, Tranche Two | Common Stock Warrant | ||||||
Debt Instrument [Line Items] | ||||||
Fair value of warrant liability | $ 60,000 | |||||
Silicon Valley Bank | Term Loans | ||||||
Debt Instrument [Line Items] | ||||||
Maximum borrowing capacity, amount | $ 15,000,000 | |||||
Number of tranches | tranche | 3 | |||||
Variable interest rate (as a percent) | 0.25% | |||||
Aggregate new capital milestone for continuation of Interest only payment period | $ 40,000,000 | |||||
Silicon Valley Bank | Term Loans | Common Stock Warrant | ||||||
Debt Instrument [Line Items] | ||||||
Warrants exercisable (in shares) | shares | 52,083 | |||||
Silicon Valley Bank | Term Loans | Base Rate | ||||||
Debt Instrument [Line Items] | ||||||
Interest rate floor (as a percent) | 5.75% | |||||
Silicon Valley Bank | Term Loans | Term Loans, Tranche One | ||||||
Debt Instrument [Line Items] | ||||||
Proceeds from borrowings, net of issuance costs | $ 5,000,000 | |||||
Silicon Valley Bank | Term Loans | Term Loans, Tranche One | Common Stock Warrant | ||||||
Debt Instrument [Line Items] | ||||||
Warrants issued, exercise price (in dollars per share) | $ / shares | $ 4.32 | |||||
Number of shares exercisable (in shares) | shares | 17,361 | |||||
Silicon Valley Bank | Term Loans | Term Loans, Tranche Two | ||||||
Debt Instrument [Line Items] | ||||||
Proceeds from borrowings, net of issuance costs | $ 5,000,000 | |||||
Silicon Valley Bank | Term Loans | Term Loans, Tranche Two | Common Stock Warrant | ||||||
Debt Instrument [Line Items] | ||||||
Number of shares exercisable (in shares) | shares | 17,361 | |||||
Silicon Valley Bank | Term Loans | Term Loans, Tranche Three | ||||||
Debt Instrument [Line Items] | ||||||
Unused borrowing capacity, expired amount | $ 5,000,000 |
Commitments and Contingencies -
Commitments and Contingencies - Narrative (Details) $ in Thousands | 1 Months Ended | 12 Months Ended | ||
Mar. 31, 2019 USD ($) lease_term_type | Dec. 31, 2023 USD ($) | Dec. 31, 2022 USD ($) | Dec. 31, 2021 USD ($) | |
Loss Contingencies [Line Items] | ||||
Operating lease, term of contract (in years) | 10 years 9 months 18 days | |||
Number of option to extend term lease | lease_term_type | 1 | |||
Operating lease, renewal term (in years) | 5 years | |||
Operating lease, annual base rent | $ 1,700 | |||
Operating lease, annual base rent increasing (as a percent) | 3% | |||
Maximum tenant improvement allowance | $ 5,400 | |||
Maximum additional tenant improvement allowance | $ 1,800 | |||
Amortization percent, additional tenant improvement allowance (as a percent) | 8% | |||
Operating lease, right-of-use asset | $ 7,510 | $ 8,219 | ||
Operating lease, liability | 9,914 | |||
Current tax expense | 0 | 1,285 | $ 129 | |
Cash paid for income taxes | 1,535 | 543 | $ 0 | |
Foreign | Australian Taxation Office | ||||
Loss Contingencies [Line Items] | ||||
Current tax expense | 1,300 | |||
Cash paid for income taxes | 590 | $ 543 | ||
Accrued liabilities | 0 | |||
Foreign | Australian Taxation Office | Research Tax Credit Carryforward | ||||
Loss Contingencies [Line Items] | ||||
Foreign tax credit | $ 136 | |||
Line of Credit | ||||
Loss Contingencies [Line Items] | ||||
Security deposit | $ 254 |
Commitments and Contingencies_2
Commitments and Contingencies - Components of Lease Cost (Details) - USD ($) $ in Thousands | 12 Months Ended | ||
Dec. 31, 2023 | Dec. 31, 2022 | Dec. 31, 2021 | |
Lease cost: | |||
Operating lease cost | $ 1,843 | $ 1,839 | $ 1,837 |
Variable lease cost | 917 | 823 | 603 |
Total lease cost | 2,760 | 2,662 | 2,440 |
Other information: | |||
Cash paid for amounts included in the measurement of lease liabilities | $ 2,062 | $ 2,009 | $ 2,117 |
Weighted-average remaining lease term (years) | 6 years 2 months 12 days | 7 years 2 months 12 days | 8 years 2 months 12 days |
Weighted-average discount rate | 10.70% | 10.70% | 10.70% |
Commitments and Contingencies_3
Commitments and Contingencies - Schedule of Future Minimum Lease Payments for Non-cancelable Operating Leases (Details) $ in Thousands | Dec. 31, 2023 USD ($) |
Commitments and Contingencies Disclosure [Abstract] | |
2024 | $ 1,939 |
2025 | 2,167 |
2026 | 2,224 |
2027 | 2,283 |
2028 | 2,344 |
Thereafter | 2,811 |
Total future minimum lease payments | 13,768 |
Less: imputed interest | (3,854) |
Operating lease liabilities | $ 9,914 |
License and Collaboration Agr_3
License and Collaboration Agreements - Narrative (Details) $ / shares in Units, $ in Thousands | 1 Months Ended | 12 Months Ended | 24 Months Ended | 55 Months Ended | |||||||||
Dec. 31, 2023 USD ($) | Dec. 31, 2021 USD ($) program candidate $ / shares shares | Sep. 30, 2021 shares | Dec. 31, 2023 USD ($) | Dec. 31, 2022 USD ($) | Dec. 31, 2021 USD ($) $ / shares | Dec. 31, 2023 USD ($) | Dec. 31, 2023 USD ($) | Nov. 30, 2023 $ / shares | Jun. 30, 2022 USD ($) | Mar. 31, 2022 USD ($) | Jun. 30, 2020 USD ($) payment | Jun. 30, 2019 USD ($) | |
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items] | |||||||||||||
Contract Liabilities | $ 17,217 | $ 17,217 | $ 74,756 | $ 17,217 | $ 17,217 | ||||||||
Revenue recognized from contract with customer | 57,500 | $ 28,200 | $ 23,400 | ||||||||||
Common Stock | |||||||||||||
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items] | |||||||||||||
Purchase price (in dollars per share) | $ / shares | $ 12.50 | ||||||||||||
Private Placement | Common Stock | |||||||||||||
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items] | |||||||||||||
Stock issued in transaction (in shares) | shares | 6,489,357 | ||||||||||||
AbbVie | |||||||||||||
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items] | |||||||||||||
Expiration period | 90 days | ||||||||||||
Potential cash payment upon license option exercise | $ 75,000 | ||||||||||||
Cumulative catch-up adjustment to revenue | $ (20,400) | ||||||||||||
AbbVie | Product | |||||||||||||
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items] | |||||||||||||
Potential future revenue recognition milestones, number of payments | payment | 1 | ||||||||||||
AbbVie | Product | Maximum | |||||||||||||
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items] | |||||||||||||
Potential future milestones receivable (up to) | $ 75,000 | ||||||||||||
AbbVie | Product | Upfront License Payment | |||||||||||||
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items] | |||||||||||||
Contract Liabilities | $ 60,000 | ||||||||||||
AbbVie | Product | Achieved Milestone | |||||||||||||
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items] | |||||||||||||
Contract Liabilities | $ 45,000 | $ 45,000 | |||||||||||
AbbVie Amendment | Product | |||||||||||||
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items] | |||||||||||||
Potential cash payment upon license option exercise | 10,000 | 10,000 | 10,000 | 10,000 | |||||||||
Potential cash payment upon achievement of certain development and commercial milestones | 153,800 | 153,800 | 153,800 | 153,800 | |||||||||
Potential cash payment upon achievement of certain sales-based cash milestones | 337,500 | 337,500 | 337,500 | 337,500 | |||||||||
AbbVie Amendment | Product | Removed from Milestone | |||||||||||||
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items] | |||||||||||||
Contract Liabilities | 30,000 | 30,000 | 30,000 | 30,000 | |||||||||
Amgen | |||||||||||||
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items] | |||||||||||||
Number of preclinical candidates | candidate | 4 | ||||||||||||
Number of existing programs | program | 1 | ||||||||||||
Number of additional programs | program | 3 | ||||||||||||
Cumulative catch-up adjustment to revenue | 6,700 | ||||||||||||
Amgen | Common Stock | |||||||||||||
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items] | |||||||||||||
Stock price period for premium on sale of stock | 30 days | ||||||||||||
Amgen | Private Placement | |||||||||||||
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items] | |||||||||||||
Stock issued in transaction (in shares) | shares | 951,980 | ||||||||||||
Purchase price (in dollars per share) | $ / shares | $ 15.76 | $ 15.76 | |||||||||||
Aggregate proceeds from sale of stock | $ 15,000 | ||||||||||||
Purchase price as premium to volume-weighted average share price (as a percent) | 25% | ||||||||||||
Fair value portion of aggregate proceeds from sale of stock | $ 11,900 | ||||||||||||
Additional consideration portion of aggregate proceeds from sale of stock | 3,100 | ||||||||||||
Amgen | Product | |||||||||||||
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items] | |||||||||||||
Contract Liabilities | 28,100 | $ 28,100 | |||||||||||
Potential future milestones receivable (up to) | 762,000 | 762,000 | 762,000 | 762,000 | |||||||||
Potential future milestones receivable per program (up to) | 381,000 | 381,000 | |||||||||||
Amgen | Product | Upfront Payment | |||||||||||||
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items] | |||||||||||||
Contract Liabilities | 25,000 | 25,000 | $ 25,000 | ||||||||||
Amgen | Product | Research and Development | |||||||||||||
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items] | |||||||||||||
Revenue recognized from contract with customer | 2,100 | ||||||||||||
Amgen | Product | Premium Payment | |||||||||||||
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items] | |||||||||||||
Contract Liabilities | $ 3,100 | $ 3,100 | |||||||||||
Adaptimmune | Product | Maximum | |||||||||||||
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items] | |||||||||||||
Potential future milestones receivable (up to) | $ 105,000 | $ 105,000 | $ 105,000 | 105,000 | |||||||||
Adaptimmune | Product | License Payment | |||||||||||||
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items] | |||||||||||||
Revenue recognized from contract with customer | 3,000 | ||||||||||||
Adaptimmune | Product | Initial License Payment | |||||||||||||
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items] | |||||||||||||
Contract Liabilities | $ 2,000 | ||||||||||||
Adaptimmune | Product | Additional License Payment | |||||||||||||
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items] | |||||||||||||
Contract Liabilities | $ 1,000 | ||||||||||||
Adaptimmune | Product | Research Support Payment | |||||||||||||
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items] | |||||||||||||
Revenue recognized from contract with customer | $ 2,100 |
License and Collaboration Agr_4
License and Collaboration Agreements - Contract Balances (Details) - USD ($) $ in Thousands | Dec. 31, 2023 | Dec. 31, 2022 |
Organization, Consolidation and Presentation of Financial Statements [Abstract] | ||
Contract Assets | $ 167 | $ 392 |
Contract Liabilities | $ 17,217 | $ 74,756 |
License and Collaboration Agr_5
License and Collaboration Agreements - Collaboration Revenue (Details) - USD ($) $ in Thousands | 12 Months Ended | ||
Dec. 31, 2023 | Dec. 31, 2022 | Dec. 31, 2021 | |
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items] | |||
Total collaboration revenue | $ 58,876 | $ 30,064 | $ 23,443 |
AbbVie | |||
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items] | |||
Total collaboration revenue | 41,925 | 17,064 | 23,443 |
Amgen | |||
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items] | |||
Total collaboration revenue | 16,487 | 11,964 | 0 |
Adaptimmune | |||
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items] | |||
Total collaboration revenue | $ 464 | $ 1,036 | $ 0 |
Stockholders' Equity - Schedule
Stockholders' Equity - Schedule of Shares of Common Stock Reserved for Future Issuance (Details) - shares | Dec. 31, 2023 | Dec. 31, 2022 |
Class of Stock [Line Items] | ||
Shares of common stock reserved for future issuance (in shares) | 16,812,497 | 16,435,186 |
Shares to be issued upon exercise of outstanding stock options | ||
Class of Stock [Line Items] | ||
Shares of common stock reserved for future issuance (in shares) | 7,968,360 | 7,058,140 |
Shares to be issued upon release of RSUs | ||
Class of Stock [Line Items] | ||
Shares of common stock reserved for future issuance (in shares) | 45,464 | 178,618 |
Shares to be issued upon conversion of common stock warrants | ||
Class of Stock [Line Items] | ||
Shares of common stock reserved for future issuance (in shares) | 2,369,351 | 3,656,497 |
Shares to be issued upon conversion of prefunded warrants | ||
Class of Stock [Line Items] | ||
Shares of common stock reserved for future issuance (in shares) | 6,102,127 | 5,182,197 |
Shares available for future stock grants | ||
Class of Stock [Line Items] | ||
Shares of common stock reserved for future issuance (in shares) | 281,984 | 314,523 |
Shares to be issued under employee stock purchase plan | ||
Class of Stock [Line Items] | ||
Shares of common stock reserved for future issuance (in shares) | 45,211 | 45,211 |
Stockholders' Equity - Narrativ
Stockholders' Equity - Narrative (Details) - USD ($) | 1 Months Ended | 2 Months Ended | 9 Months Ended | 12 Months Ended | ||||||||||||
Aug. 01, 2023 | Feb. 29, 2024 | Jan. 31, 2024 | Nov. 30, 2023 | Jun. 30, 2023 | Apr. 30, 2023 | Sep. 30, 2022 | Aug. 31, 2022 | Sep. 30, 2021 | Jun. 30, 2018 | Oct. 31, 2022 | Sep. 30, 2022 | Dec. 31, 2023 | Dec. 31, 2022 | Dec. 31, 2021 | Jul. 31, 2017 | |
Class of Stock [Line Items] | ||||||||||||||||
Proceeds from issuance or sale of equity, gross | $ 162,400,000 | |||||||||||||||
Stock issuance costs incurred | $ 266,000 | |||||||||||||||
Proceeds from sale of common stock and warrants, net of offering costs | $ 91,000,000 | |||||||||||||||
Proceeds from sale of common stock and warrants, net of offering costs | $ 161,905,000 | $ 106,716,000 | $ 90,733,000 | |||||||||||||
Retirement of treasury stock (in shares) | 1,250,467 | |||||||||||||||
Common stock, shares issued (in shares) | 60,347,457 | 47,234,900 | ||||||||||||||
Proceeds from exercise of warrants | $ 1,851,000 | $ 0 | 0 | |||||||||||||
Shares of common stock reserved for future issuance (in shares) | 16,812,497 | 16,435,186 | ||||||||||||||
Vesting period (in years) | 4 years | |||||||||||||||
Term (in years) | 10 years | |||||||||||||||
Unrecognized compensation cost related to nonvested stock options | $ 22,400,000 | |||||||||||||||
Weighted-average period over which unrecognized compensation expense related to nonvested stock options is expected to be recognized (in years) | 2 years 8 months 12 days | |||||||||||||||
Subsequent Event | ||||||||||||||||
Class of Stock [Line Items] | ||||||||||||||||
Proceeds from exercise of warrants | $ 17,600,000 | |||||||||||||||
Sales Agreement | Cowen & Co. | ||||||||||||||||
Class of Stock [Line Items] | ||||||||||||||||
Stock issuance costs incurred | $ 488,000 | |||||||||||||||
Maximum amount of common stock eligible to be sold (up to) | $ 75,000,000 | |||||||||||||||
2018 Plan | ||||||||||||||||
Class of Stock [Line Items] | ||||||||||||||||
Percentage of outstanding stock maximum (as a percent) | 5% | |||||||||||||||
2018 Plan | Maximum | ||||||||||||||||
Class of Stock [Line Items] | ||||||||||||||||
Additional number of shares authorized (in shares) | 1,500,000 | |||||||||||||||
2018 Plan | Subsequent Event | ||||||||||||||||
Class of Stock [Line Items] | ||||||||||||||||
Additional number of shares authorized (in shares) | 1,500,000 | |||||||||||||||
Incentive Stock Option | ||||||||||||||||
Class of Stock [Line Items] | ||||||||||||||||
Term (in years) | 10 years | |||||||||||||||
Stock Plan 2018, Stock Plan 2015 And Equity Incentive Plan 2015 | ||||||||||||||||
Class of Stock [Line Items] | ||||||||||||||||
Number of shares authorized (in shares) | 9,616,862 | |||||||||||||||
Prefunded warrants | ||||||||||||||||
Class of Stock [Line Items] | ||||||||||||||||
Shares of common stock reserved for future issuance (in shares) | 6,102,127 | 5,182,197 | ||||||||||||||
Inducement Grant | Common Stock | ||||||||||||||||
Class of Stock [Line Items] | ||||||||||||||||
Options granted (in shares) | 185,000 | 160,000 | ||||||||||||||
Exercise price (in dollars per share) | $ 13.44 | $ 8.38 | ||||||||||||||
Legacy Plan Cancellations | 2018 Plan | ||||||||||||||||
Class of Stock [Line Items] | ||||||||||||||||
Number of shares authorized (in shares) | 1,972,784 | |||||||||||||||
Stock options | ||||||||||||||||
Class of Stock [Line Items] | ||||||||||||||||
Shares of common stock reserved for future issuance (in shares) | 7,968,360 | 7,058,140 | ||||||||||||||
Aggregate intrinsic value of stock options exercised | $ 7,600,000 | $ 1,100,000 | 546,000 | |||||||||||||
Fair value of shares vested | $ 9,600,000 | $ 8,600,000 | 3,400,000 | |||||||||||||
Restricted stock units | ||||||||||||||||
Class of Stock [Line Items] | ||||||||||||||||
Shares of common stock reserved for future issuance (in shares) | 45,464 | 178,618 | ||||||||||||||
Aggregate intrinsic value of RSU's released | $ 1,000,000 | $ 527,000 | ||||||||||||||
Fair value of RSUs vesting | $ 1,400,000 | $ 735,000 | $ 0 | |||||||||||||
Stock options and Restricted stock units | ||||||||||||||||
Class of Stock [Line Items] | ||||||||||||||||
Nonvested awards (in shares) | 3,600,000 | |||||||||||||||
Common Stock | ||||||||||||||||
Class of Stock [Line Items] | ||||||||||||||||
Purchase price (in dollars per share) | $ 12.50 | |||||||||||||||
Exchange of common stock for prefunded warrants (in shares) | 1,200,000 | (1,200,000) | ||||||||||||||
Common Stock | Subsequent Event | ||||||||||||||||
Class of Stock [Line Items] | ||||||||||||||||
Common stock, shares issued (in shares) | 3,199,879 | 1,694,282 | ||||||||||||||
Treasury | ||||||||||||||||
Class of Stock [Line Items] | ||||||||||||||||
Exchange of common stock for prefunded warrants (in shares) | 1,200,000 | 1,200,000 | ||||||||||||||
Retirement of treasury stock (in shares) | 1,250,467 | |||||||||||||||
Underwritten Public Offering | ||||||||||||||||
Class of Stock [Line Items] | ||||||||||||||||
Proceeds from issuance or sale of equity, net | $ 152,200,000 | |||||||||||||||
Stock issuance costs incurred | $ 440,000 | |||||||||||||||
Underwritten Public Offering | Common Stock | ||||||||||||||||
Class of Stock [Line Items] | ||||||||||||||||
Stock issued in transaction (in shares) | 9,791,832 | |||||||||||||||
Public Stock Offering | ||||||||||||||||
Class of Stock [Line Items] | ||||||||||||||||
Stock issued in transaction (in shares) | 15,509,282 | |||||||||||||||
Stock issuance costs incurred | $ 438,000 | |||||||||||||||
Proceeds from sale of equity | $ 106,700,000 | |||||||||||||||
Maximum amount of common stock eligible to be sold (up to) | $ 100,000,000 | |||||||||||||||
Public Stock Offering | Sales Agreement | ||||||||||||||||
Class of Stock [Line Items] | ||||||||||||||||
Stock issued in transaction (in shares) | 919,413 | |||||||||||||||
Purchase price (in dollars per share) | $ 10.93 | |||||||||||||||
Stock issuance costs incurred | $ 355,000 | |||||||||||||||
Proceeds from sale of common stock and warrants, net of offering costs | $ 10,000,000 | |||||||||||||||
Public Stock Offering | Sales Agreement | TD Cowen | ||||||||||||||||
Class of Stock [Line Items] | ||||||||||||||||
Percentage of compensation for services (as a percent) | 3% | |||||||||||||||
Private Placement | Common Stock | ||||||||||||||||
Class of Stock [Line Items] | ||||||||||||||||
Stock issued in transaction (in shares) | 6,489,357 | |||||||||||||||
Employee stock purchase plan | ||||||||||||||||
Class of Stock [Line Items] | ||||||||||||||||
Shares of common stock reserved for future issuance (in shares) | 45,211 | |||||||||||||||
Prefunded warrants | ||||||||||||||||
Class of Stock [Line Items] | ||||||||||||||||
Warrants exercisable (in shares) | 3,191,487 | |||||||||||||||
Warrants issued, exercise price (in dollars per share) | $ 0.001 | $ 0.001 | ||||||||||||||
Prefunded warrants | Subsequent Event | ||||||||||||||||
Class of Stock [Line Items] | ||||||||||||||||
Warrants exercised (in shares) | 3,200,000 | |||||||||||||||
Prefunded warrants | Common Stock | ||||||||||||||||
Class of Stock [Line Items] | ||||||||||||||||
Purchase price (in dollars per share) | $ 12.499 | $ 9.40 | ||||||||||||||
Prefunded warrants | Underwritten Public Offering | ||||||||||||||||
Class of Stock [Line Items] | ||||||||||||||||
Warrants exercisable (in shares) | 3,200,000 | |||||||||||||||
Exchange Warrants | Prefunded warrants | ||||||||||||||||
Class of Stock [Line Items] | ||||||||||||||||
Warrants exercisable (in shares) | 1,200,000 | |||||||||||||||
Common stock warrants | Subsequent Event | ||||||||||||||||
Class of Stock [Line Items] | ||||||||||||||||
Warrants exercised (in shares) | 2,309,404 |
Stockholders' Equity - Schedu_2
Stockholders' Equity - Schedule of Warrants (Details) - $ / shares | 12 Months Ended | |
Dec. 31, 2023 | Dec. 31, 2022 | |
Warrants Outstanding | ||
Warrants outstanding (in shares) | 3,656,497 | |
Exercised (in shares) | (1,287,146) | |
Warrants outstanding and exercisable (in shares) | 2,369,351 | 3,656,497 |
Weighted- average Exercise Price | ||
Weighted average, exercise price, outstanding (in dollars per share) | $ 12.66 | |
Exercise (in dollars per share) | 12.74 | |
Weighted average, exercise price, outstanding and exercisable (in dollars per share) | $ 12.62 | $ 12.66 |
Weighted- average Remaining Contract Term (in years) | ||
Weighted-average remaining contractual term, outstanding | 1 month 24 days | 1 year 1 month 13 days |
Stockholders' Equity - Schedu_3
Stockholders' Equity - Schedule of Option Activity (Details) - Stock options $ / shares in Units, $ in Thousands | 12 Months Ended |
Dec. 31, 2023 USD ($) $ / shares shares | |
Options Outstanding | |
Outstanding at beginning of period (in shares) | shares | 7,058,140 |
Granted (in shares) | shares | 2,816,197 |
Exercised (in shares) | shares | (858,511) |
Forfeited (in shares) | shares | (1,047,466) |
Outstanding at ending of period (in shares) | shares | 7,968,360 |
Vested and expected to vest (in shares) | shares | 7,790,360 |
Exercisable (in shares) | shares | 4,462,145 |
Weighted- average Exercise Price (per share) | |
Outstanding at beginning of period (in dollars per share) | $ / shares | $ 8.37 |
Granted (in dollars per share) | $ / shares | 9.50 |
Exercised (in dollars per share) | $ / shares | 5.91 |
Forfeited (in dollars per share) | $ / shares | 10.40 |
Outstanding at ending of period (in dollars per share) | $ / shares | 8.77 |
Vested and expected to vest (in dollars per share) | $ / shares | 8.79 |
Exercisable (in dollars per share) | $ / shares | $ 7.79 |
Weighted- average Remaining Contract Term (in years) | |
Outstanding (in years) | 6 years 11 months 15 days |
Vested and expected to vest (in years) | 6 years 11 months 12 days |
Exercisable (in years) | 5 years 7 months 13 days |
Aggregate Intrinsic Value (in thousands) | |
Outstanding | $ | $ 82,254 |
Vested and expected to vest | $ | 80,307 |
Exercisable | $ | $ 50,542 |
Stockholders' Equity - Schedu_4
Stockholders' Equity - Schedule of RSU Activity (Details) - Restricted stock units $ / shares in Units, $ in Thousands | 12 Months Ended |
Dec. 31, 2023 USD ($) $ / shares shares | |
Number of Shares | |
Non-vested at beginning of period (in shares) | shares | 178,618 |
Vested (in shares) | shares | (114,651) |
Forfeited (in shares) | shares | (18,503) |
Non-vested at ending of period (in shares) | shares | 45,464 |
Weighted- Average Grant Date Fair Value (per share) | |
Non-vested at beginning of period (in dollars per share) | $ / shares | $ 12 |
Vested (in dollars per share) | $ / shares | 12 |
Forfeited (in dollars per share) | $ / shares | 12 |
Non-vested at ending of period (in dollars per share) | $ / shares | $ 12 |
Weighted- average Remaining Contract Life (in years) | |
Non-vested (in years) | 0 years |
Aggregate Intrinsic Value (in thousands) | |
Non-vested | $ | $ 867 |
Stockholders' Equity - Schedu_5
Stockholders' Equity - Schedule of Stock Option Assumptions (Details) - $ / shares | 12 Months Ended | ||
Dec. 31, 2023 | Dec. 31, 2022 | Dec. 31, 2021 | |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | |||
Weighted-average estimated fair value at grant (in dollars per share) | $ 6.94 | $ 7.56 | $ 8.44 |
Risk-free interest rate, minimum (as a percent) | 3.36% | 1.39% | 0.25% |
Risk-free interest rate, maximum (as a percent) | 4.67% | 4.04% | 1.30% |
Expected stock price volatility, minimum (as a percent) | 81% | 80% | 79% |
Expected stock price volatility, maximum (as a percent) | 85% | 83% | 83% |
Expected dividend yield (as a percent) | 0% | 0% | 0% |
Minimum | |||
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | |||
Expected term of options (in years) | 5 years 3 months 7 days | 5 years 3 months 7 days | 3 years 5 months 26 days |
Maximum | |||
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | |||
Expected term of options (in years) | 6 years 29 days | 6 years 29 days | 6 years 29 days |
Stockholders' Equity - Schedu_6
Stockholders' Equity - Schedule of Stock-based Compensation Expense (Details) - USD ($) $ in Thousands | 12 Months Ended | ||
Dec. 31, 2023 | Dec. 31, 2022 | Dec. 31, 2021 | |
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items] | |||
Total stock-based compensation expense | $ 10,630 | $ 9,648 | $ 6,240 |
Research and development | |||
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items] | |||
Total stock-based compensation expense | 6,251 | 5,713 | 3,347 |
General and administrative | |||
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items] | |||
Total stock-based compensation expense | $ 4,379 | $ 3,935 | $ 2,893 |
Income Taxes - Schedule of Dome
Income Taxes - Schedule of Domestic and Foreign Components of Loss Before Taxes (Details) - USD ($) $ in Thousands | 12 Months Ended | ||
Dec. 31, 2023 | Dec. 31, 2022 | Dec. 31, 2021 | |
Income Tax Disclosure [Abstract] | |||
Domestic | $ (32,450) | $ (55,475) | $ (48,932) |
Foreign | 369 | 43 | (1,488) |
Loss before taxes | $ (32,081) | $ (55,432) | $ (50,420) |
Income Taxes - Schedule of Prov
Income Taxes - Schedule of Provision for Income Taxes (Details) - USD ($) $ in Thousands | 12 Months Ended | ||
Dec. 31, 2023 | Dec. 31, 2022 | Dec. 31, 2021 | |
Current: | |||
U.S. - Federal | $ 47 | $ (981) | $ 0 |
U.S. - State | 4 | (16) | 0 |
Foreign | 0 | (1,285) | (129) |
Total current | 51 | (2,282) | (129) |
Deferred: | |||
Foreign | (154) | (48) | 216 |
Total deferred | (154) | (48) | 216 |
Total income tax (expense) benefit | $ (103) | $ (2,330) | $ 87 |
Income Taxes - Schedule of Effe
Income Taxes - Schedule of Effective Tax Rate of Provision for Income Taxes Differs from Federal Statutory Rate (Details) | 12 Months Ended | ||
Dec. 31, 2023 | Dec. 31, 2022 | Dec. 31, 2021 | |
Income Tax Disclosure [Abstract] | |||
U.S. Statutory rate | 21% | 21% | 21% |
Effect of: | |||
State taxes (net of federal benefit) | 0.30% | 0.10% | 0% |
Permanent differences | 0.30% | 0% | (0.40%) |
Federal research and development credit | 9.20% | 5% | 4.50% |
Change in valuation allowance | (29.10%) | (28.60%) | (21.40%) |
Global intangible low-taxed income recapture | 0% | (0.60%) | (1.40%) |
Stock-based compensation | (1.60%) | (1.90%) | (1.80%) |
Foreign rate differential | (0.10%) | 0% | 0.20% |
Other | (0.30%) | 0% | (0.50%) |
Voluntary disclosure net change in prior years’ tax liabilities | 0% | 0.80% | 0% |
Effective income tax rate | (0.30%) | (4.20%) | 0.20% |
Income Taxes - Narrative (Detai
Income Taxes - Narrative (Details) - USD ($) | 12 Months Ended | ||||
Dec. 31, 2023 | Dec. 31, 2022 | Dec. 31, 2021 | Dec. 31, 2020 | Dec. 31, 2018 | |
Income Taxes [Line Items] | |||||
Income tax expense | $ 103,000 | $ 2,330,000 | $ (87,000) | ||
Current federal, state and local, tax expense | 1,000,000 | ||||
Current tax expense | 0 | 1,285,000 | 129,000 | ||
Deferred tax expense | 154,000 | 48,000 | (216,000) | ||
Increase in valuation allowance | 9,100,000 | 16,100,000 | |||
Unrecognized tax benefits that would impact effective tax rate | 0 | ||||
Unrecognized tax benefits | 2,874,000 | 2,149,000 | 1,553,000 | $ 990,000 | |
Accrued interest or penalties related to unrecognized tax benefits | $ 0 | $ 0 | $ 0 | ||
US | |||||
Income Taxes [Line Items] | |||||
Research and development, capitalized and amortized period (in years) | 5 years | ||||
Outline United States | |||||
Income Taxes [Line Items] | |||||
Research and development, capitalized and amortized period (in years) | 15 years | ||||
Nivalis Therapeutics, Inc. | |||||
Income Taxes [Line Items] | |||||
Tax credit and net operating loss carryforwards | $ 0 |
Income Taxes - Schedule of Sign
Income Taxes - Schedule of Significant Components of Deferred Tax Assets and Liabilities (Details) - USD ($) $ in Thousands | Dec. 31, 2023 | Dec. 31, 2022 |
Deferred tax assets: | ||
Net operating loss | $ 23,205 | $ 18,590 |
Research and development credits | 9,259 | 6,240 |
Intangible asset basis | 4 | 2 |
Lease liability | 2,126 | 2,315 |
Deferred revenue | 3,600 | 14,752 |
Stock based compensation | 2,428 | 2,343 |
Capitalized research and experimental costs | 24,147 | 12,681 |
Other | 1,088 | 156 |
Gross deferred tax assets | 65,857 | 57,079 |
Valuation allowance | (63,897) | (54,841) |
Total deferred tax assets, net of valuation allowance | 1,960 | 2,238 |
Deferred tax liabilities: | ||
Prepaid expenses | (251) | (173) |
Fixed asset basis | (126) | (182) |
Right-of-use asset basis | (1,583) | (1,728) |
Total deferred tax liability | (1,960) | (2,083) |
Net deferred tax assets and liabilities | $ 0 | $ 155 |
Income Taxes - Schedule of Net
Income Taxes - Schedule of Net Operating Loss Carryforwards (Details) - USD ($) $ in Thousands | Dec. 31, 2023 | Dec. 31, 2022 |
State | ||
Income Taxes [Line Items] | ||
Net operating loss carryforwards | $ 6,778 | $ 6,433 |
After January 1 2018 | Federal | ||
Income Taxes [Line Items] | ||
Net operating loss carryforwards | $ 108,393 | $ 85,012 |
Income Taxes - Schedule of Tax
Income Taxes - Schedule of Tax Credit Carryforwards (Details) - USD ($) $ in Thousands | Dec. 31, 2023 | Dec. 31, 2022 |
Income Taxes [Line Items] | ||
Research and development credits | $ 9,259 | $ 6,240 |
Federal | ||
Income Taxes [Line Items] | ||
Research and development credits | 11,584 | 7,892 |
Foreign | ||
Income Taxes [Line Items] | ||
Research and development credits | $ 578 | $ 527 |
Income Taxes - Schedule of Acti
Income Taxes - Schedule of Activity Related to Unrecognized Tax Benefits (Details) - USD ($) $ in Thousands | 12 Months Ended | ||
Dec. 31, 2023 | Dec. 31, 2022 | Dec. 31, 2021 | |
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward] | |||
Unrecognized benefits – beginning of year | $ 2,149 | $ 1,553 | $ 990 |
Gross increases (decreases) – prior year tax positions | (2) | 0 | 0 |
Gross increases – current year tax positions | 727 | 596 | 563 |
Unrecognized benefit – end of year | $ 2,874 | $ 2,149 | $ 1,553 |
Related Party Transactions (Det
Related Party Transactions (Details) - USD ($) $ in Thousands | 1 Months Ended | 12 Months Ended | |||||
Jan. 31, 2024 | Dec. 31, 2023 | Sep. 30, 2021 | Dec. 31, 2023 | Dec. 31, 2022 | Dec. 31, 2021 | Feb. 29, 2024 | |
Related Party Transaction [Line Items] | |||||||
Proceeds from exercise of warrants | $ 1,851 | $ 0 | $ 0 | ||||
Proceeds from sale of common stock and warrants, net of offering costs | $ 91,000 | ||||||
Subsequent Event | |||||||
Related Party Transaction [Line Items] | |||||||
Proceeds from exercise of warrants | $ 17,600 | ||||||
Exchange Warrants | Prefunded warrants | |||||||
Related Party Transaction [Line Items] | |||||||
Warrants exercisable (in shares) | 1,200,000 | ||||||
Affiliated Entity | Prefunded warrants | Subsequent Event | |||||||
Related Party Transaction [Line Items] | |||||||
Warrants exercisable (in shares) | 3,200,000 | ||||||
Affiliated Entity | 2021 Security Purchases Agreement | Prefunded warrants | |||||||
Related Party Transaction [Line Items] | |||||||
Warrants exercisable (in shares) | 2,340,424 | ||||||
Affiliated Entity | Exchange of Stock | Exchange Warrants | Prefunded warrants | |||||||
Related Party Transaction [Line Items] | |||||||
Warrants exercisable (in shares) | 1,200,000 | ||||||
Common Stock and Common Stock Warrants | Affiliated Entity | |||||||
Related Party Transaction [Line Items] | |||||||
Proceeds from exercise of warrants | $ 1,900 | ||||||
Common Stock and Common Stock Warrants | Affiliated Entity | Subsequent Event | |||||||
Related Party Transaction [Line Items] | |||||||
Proceeds from exercise of warrants | $ 17,600 | ||||||
Common Stock and Common Stock Warrants | Affiliated Entity | 2021 Security Purchases Agreement | |||||||
Related Party Transaction [Line Items] | |||||||
Proceeds from sale of common stock and warrants, net of offering costs | $ 57,000 | ||||||
Common Stock | |||||||
Related Party Transaction [Line Items] | |||||||
Exchange of common stock for prefunded warrants (in shares) | (1,200,000) | 1,200,000 | |||||
Common Stock | Affiliated Entity | Alpine Immune Sciences | |||||||
Related Party Transaction [Line Items] | |||||||
Ownership percentage by noncontrolling owners (as a percent) | 5% | 5% | |||||
Common Stock | Affiliated Entity | Alpine Immune Sciences | Subsequent Event | |||||||
Related Party Transaction [Line Items] | |||||||
Ownership percentage by noncontrolling owners (as a percent) | 5% | 5% | |||||
Common Stock | Affiliated Entity | 2021 Security Purchases Agreement | |||||||
Related Party Transaction [Line Items] | |||||||
Stock issued in transaction (in shares) | 3,723,402 | ||||||
Common Stock | Affiliated Entity | 2021 Security Purchases Agreement | Alpine Immune Sciences | |||||||
Related Party Transaction [Line Items] | |||||||
Ownership percentage by noncontrolling owners (as a percent) | 5% | ||||||
Common Stock | Affiliated Entity | Exchange of Stock | |||||||
Related Party Transaction [Line Items] | |||||||
Exchange of common stock for prefunded warrants (in shares) | 1,200,000 | ||||||
Common Stock Warrant | Affiliated Entity | |||||||
Related Party Transaction [Line Items] | |||||||
Warrants exercisable (in shares) | 219,692 | 219,692 | |||||
Common Stock Warrant | Affiliated Entity | Subsequent Event | |||||||
Related Party Transaction [Line Items] | |||||||
Warrants exercisable (in shares) | 1,379,887 |
401(k) Retirement Plan (Details
401(k) Retirement Plan (Details) - USD ($) $ in Thousands | 12 Months Ended | |
Dec. 31, 2023 | Dec. 31, 2022 | |
Retirement Benefits [Abstract] | ||
Employee contributions plan, cost | $ 493 | $ 287 |