Document and Entity Information
Document and Entity Information - USD ($) | 12 Months Ended | ||
Dec. 31, 2023 | Mar. 08, 2024 | Jun. 30, 2023 | |
Cover [Abstract] | |||
Document Type | 10-K | ||
Amendment Flag | false | ||
Document Period End Date | Dec. 31, 2023 | ||
Document Fiscal Year Focus | 2023 | ||
Document Fiscal Period Focus | FY | ||
Document Annual Report | true | ||
Document Transition Report | false | ||
Security Exchange Name | NASDAQ | ||
Trading Symbol | LIFE | ||
Entity Registrant Name | ATYR PHARMA, INC. | ||
Entity Central Index Key | 0001339970 | ||
Entity Current Reporting Status | Yes | ||
Entity Interactive Data Current | Yes | ||
Current Fiscal Year End Date | --12-31 | ||
Entity Well-known Seasoned Issuer | No | ||
Entity Voluntary Filers | No | ||
Entity Filer Category | Non-accelerated Filer | ||
Entity Shell Company | false | ||
Entity Small Business | true | ||
Entity Emerging Growth Company | false | ||
ICFR Auditor Attestation Flag | false | ||
Entity Common Stock, Shares Outstanding | 67,750,024 | ||
Entity Public Float | $ 120,774,416 | ||
Entity File Number | 001-37378 | ||
Entity Tax Identification Number | 20-3435077 | ||
Entity Address, Address Line One | 10240 Sorrento Valley Road | ||
Entity Address, Address Line Two | Suite 300 | ||
Entity Address, City or Town | San Diego | ||
Entity Address, State or Province | CA | ||
Entity Incorporation, State or Country Code | DE | ||
Entity Address, Postal Zip Code | 92121 | ||
City Area Code | 858 | ||
Local Phone Number | 731-8389 | ||
Document Financial Statement Error Correction [Flag] | false | ||
Title of 12(b) Security | Common Stock, par value $0.001 per share | ||
Documents Incorporated by Reference | Portions of the registrant’s definitive proxy statement to be filed with the Securities and Exchange Commission (SEC), pursuant to Regulation 14A in connection with the registrant’s 2024 Annual Meeting of Stockholders, which will be filed subsequent to the date hereof, are incorporated by reference into Part III of this Annual Report on Form 10-K. Such proxy statement will be filed with the SEC not later than 120 days following the end of the registrant’s fiscal year ended December 31, 2023 | ||
Auditor Name | Ernst & Young LLP | ||
Auditor Location | San Diego, California | ||
Auditor Firm ID | 42 |
Consolidated Balance Sheets
Consolidated Balance Sheets - USD ($) $ in Thousands | Dec. 31, 2023 | Dec. 31, 2022 |
Current assets: | ||
Cash and cash equivalents | $ 22,544 | $ 9,981 |
Available-for-sale investments | 75,622 | 56,165 |
Other receivables | 2,436 | 11,775 |
Prepaid expenses | 2,390 | 2,950 |
Total current assets | 102,992 | 80,871 |
Restricted cash | 3,484 | 3,165 |
Property and equipment, net | 5,531 | 3,059 |
Operating lease, right-of-use assets | 6,727 | 7,250 |
Financing lease, right-of-use assets | 1,788 | 1,248 |
Other assets | 131 | 193 |
Total assets | 120,653 | 95,786 |
Current liabilities: | ||
Accounts payable | 3,529 | 3,106 |
Accrued expenses | 11,559 | 9,862 |
Current portion of operating lease liability | 831 | 630 |
Current portion of financing lease liability | 497 | 264 |
Total current liabilities | 16,416 | 13,862 |
Long-term operating lease liability, net of current portion | 12,339 | 9,633 |
Long-term financing lease liability, net of current portion | 1,428 | 1,007 |
Commitments and contingencies (Note 6) | ||
Stockholders’ equity: | ||
Preferred stock, $0.001 par value per share; 5,000,000 undesignated authorized shares as of December 31, 2023 and 2022, respectively; no shares issued or outstanding as of December 31, 2023 and 2022, respectively | ||
Common stock, $0.001 par value per share; 170,000,000 and 85,000,000 authorized shares as of December 31, 2023 and 2022, respectively; issued and outstanding shares - 63,286,404 and 29,498,488 as of December 31, 2023 and 2022, respectively | 63 | 29 |
Additional paid-in capital | 558,692 | 489,502 |
Accumulated other comprehensive loss | (74) | (433) |
Accumulated deficit | (468,023) | (417,634) |
Total aTyr Pharma stockholders’ equity | 90,658 | 71,464 |
Noncontrolling interest in Pangu BioPharma Limited | (188) | (180) |
Total stockholders' equity | 90,470 | 71,284 |
Total liabilities and stockholders’ equity | $ 120,653 | $ 95,786 |
Consolidated Balance Sheets (Pa
Consolidated Balance Sheets (Parenthetical) - $ / shares | Dec. 31, 2023 | Dec. 31, 2022 |
Preferred stock, par value | $ 0.001 | $ 0.001 |
Preferred stock, shares authorized | 5,000,000 | 5,000,000 |
Preferred stock, shares issued | 0 | 0 |
Preferred stock, shares outstanding | 0 | 0 |
Common stock, par value | $ 0.001 | $ 0.001 |
Common stock, shares authorized | 170,000,000 | 85,000,000 |
Common stock, shares issued | 63,286,404 | 29,498,488 |
Common stock, shares outstanding | 63,286,404 | 29,498,488 |
Consolidated Statements of Oper
Consolidated Statements of Operations - USD ($) $ in Thousands | 12 Months Ended | ||
Dec. 31, 2023 | Dec. 31, 2022 | Dec. 31, 2021 | |
Revenues: | |||
Total revenues | $ 353 | $ 10,386 | $ 0 |
Revenue, Product and Service [Extensible Enumeration] | License and collaboration agreement revenues | License and collaboration agreement revenues | License and collaboration agreement revenues |
Operating expenses: | |||
Research and development | $ 42,293 | $ 42,808 | $ 23,264 |
General and administrative | 12,979 | 13,982 | 10,751 |
Total operating expenses | 55,272 | 56,790 | 34,015 |
Loss from operations | (54,919) | (46,404) | (34,015) |
Total other income (expense), net | 4,522 | 1,061 | 238 |
Consolidated net loss | (50,397) | (45,343) | (33,777) |
Net loss attributable to noncontrolling interest in Pangu BioPharma Limited | 8 | 5 | 9 |
Net loss attributable to aTyr Pharma, Inc. | $ (50,389) | $ (45,338) | $ (33,768) |
Net loss per share - basic | $ (0.94) | $ (1.6) | $ (1.77) |
Net loss per share - diluted | $ (0.94) | $ (1.6) | $ (1.77) |
Shares used in computing net loss per share, basic | 53,606,488 | 28,419,569 | 19,080,878 |
Shares used in computing net loss per share, diluted | 53,606,488 | 28,419,569 | 19,080,878 |
Consolidated Statements of Comp
Consolidated Statements of Comprehensive Loss - USD ($) $ in Thousands | 12 Months Ended | ||
Dec. 31, 2023 | Dec. 31, 2022 | Dec. 31, 2021 | |
Statement of Comprehensive Income [Abstract] | |||
Consolidated net loss | $ (50,397) | $ (45,343) | $ (33,777) |
Other comprehensive loss: | |||
Change in unrealized gain (loss) on available-for-sale investments, net of tax | 359 | (170) | (220) |
Comprehensive loss | (50,038) | (45,513) | (33,997) |
Comprehensive loss attributable to noncontrolling interest in Pangu BioPharma Limited | 8 | 5 | 9 |
Comprehensive loss attributable to aTyr Pharma, Inc. common stockholders | $ (50,030) | $ (45,508) | $ (33,988) |
Consolidated Statements of Stoc
Consolidated Statements of Stockholders' Equity - USD ($) $ in Thousands | Total | Common Stock [Member] | Additional Paid-In Capital [Member] | Other Comprehensive Gain/(Loss) [Member] | Accumulated Deficit [Member] | Noncontrolling Interest [Member] |
Beginning balance at Dec. 31, 2020 | $ 31,484 | $ 11 | $ 370,210 | $ (43) | $ (338,528) | $ (166) |
Beginning balance, Shares at Dec. 31, 2020 | 11,018,954 | |||||
Issuance of common stock upon release of restricted stock units, Shares | 4,177 | |||||
Issuance of common stock upon exercise of stock options | 62 | 62 | ||||
Issuance of common stock upon exercise of stock options, Shares | 10,751 | |||||
Issuance of common stock pursuant to employee stock purchase plan | 11 | 11 | ||||
Issuance of common stock pursuant to employee stock purchase plan, Shares | 3,382 | |||||
Issuance of common stock from at-the-market offerings, net of offering costs | 14,070 | $ 3 | 14,067 | |||
Issuance of common stock from at the market offerings, net of offering costs, Shares | 2,974,521 | |||||
Issuance of common stock from committed purchase agreement, net of offering costs | 15,236 | $ 3 | 15,233 | |||
Issuance of common stock from committed purchase agreement, net of offering costs, Shares | 3,000,000 | |||||
Issuance of common stock from underwritten follow-on offering, net of offering costs | 80,646 | $ 11 | 80,635 | |||
Issuance of common stock from underwritten follow-on offering, net of offering costs, Shares | 10,781,250 | |||||
Stock-based compensation | 1,614 | 1,614 | ||||
Net unrealized gain (loss) on investments, net of tax | (220) | (220) | ||||
Net loss | (33,777) | (33,768) | (9) | |||
Ending balance at Dec. 31, 2021 | 109,126 | $ 28 | 481,832 | (263) | (372,296) | (175) |
Ending balance, Shares at Dec. 31, 2021 | 27,793,035 | |||||
Issuance of common stock upon release of restricted stock units, Shares | 2,500 | |||||
Issuance of common stock upon exercise of stock options | 1 | 1 | ||||
Issuance of common stock upon exercise of stock options, Shares | 259 | |||||
Issuance of common stock pursuant to employee stock purchase plan | 44 | 44 | ||||
Issuance of common stock pursuant to employee stock purchase plan, Shares | 20,612 | |||||
Issuance of common stock from at-the-market offerings, net of offering costs | 5,472 | $ 1 | 5,471 | |||
Issuance of common stock from at the market offerings, net of offering costs, Shares | 1,682,082 | |||||
Stock-based compensation | 2,154 | 2,154 | ||||
Net unrealized gain (loss) on investments, net of tax | (170) | (170) | ||||
Net loss | (45,343) | (45,338) | (5) | |||
Ending balance at Dec. 31, 2022 | 71,284 | $ 29 | 489,502 | (433) | (417,634) | (180) |
Ending balance, Shares at Dec. 31, 2022 | 29,498,488 | |||||
Issuance of common stock upon release of restricted stock units, Shares | 58,111 | |||||
Issuance of common stock pursuant to employee stock purchase plan | 105 | 105 | ||||
Issuance of common stock pursuant to employee stock purchase plan, Shares | 74,010 | |||||
Issuance of common stock from at-the-market offerings, net of offering costs | 18,446 | $ 11 | 18,435 | |||
Issuance of common stock from at the market offerings, net of offering costs, Shares | 10,530,795 | |||||
Issuance of common stock from underwritten follow-on offering, net of offering costs | 48,073 | $ 23 | 48,050 | |||
Issuance of common stock from underwritten follow-on offering, net of offering costs, Shares | 23,125,000 | |||||
Stock-based compensation | 2,600 | 2,600 | ||||
Net unrealized gain (loss) on investments, net of tax | 359 | 359 | ||||
Net loss | (50,397) | (50,389) | (8) | |||
Ending balance at Dec. 31, 2023 | $ 90,470 | $ 63 | $ 558,692 | $ (74) | $ (468,023) | $ (188) |
Ending balance, Shares at Dec. 31, 2023 | 63,286,404 |
Consolidated Statements of Cash
Consolidated Statements of Cash Flows - USD ($) $ in Thousands | 12 Months Ended | ||
Dec. 31, 2023 | Dec. 31, 2022 | Dec. 31, 2021 | |
Cash flows from operating activities: | |||
Consolidated net loss | $ (50,397) | $ (45,343) | $ (33,777) |
Adjustments to reconcile net loss to net cash used in operating activities: | |||
Depreciation and amortization | 592 | 232 | 475 |
Stock-based compensation | 2,600 | 2,154 | 1,614 |
(Accretion) amortization of (discount) premium of available-for-sale investment securities | (3,171) | 533 | 366 |
Amortization of right-of-use assets | 2,149 | 1,463 | 829 |
(Gain) loss on disposal of property and equipment | (6) | (92) | 6 |
Changes in operating assets and liabilities: | |||
Other receivables | 9,054 | (11,923) | 1,604 |
Prepaid expenses and other assets | 622 | 2,238 | (3,378) |
Accounts payable and accrued expenses | 3,262 | 6,741 | 47 |
Operating lease liability | 2,074 | 2,111 | (861) |
Net cash used in operating activities | (33,221) | (41,886) | (33,075) |
Cash flows from investing activities: | |||
Purchases of property and equipment | (4,215) | (1,641) | (192) |
Purchases of available-for-sale investment securities | (106,977) | (42,118) | (126,506) |
Maturities of available-for-sale investment securities | 91,050 | 90,825 | 35,082 |
Proceeds from sale of property and equipment | 15 | 179 | 50 |
Net cash (used in) provided by investing activities | (20,127) | 47,245 | (91,566) |
Cash flows from financing activities: | |||
Proceeds from issuance of common stock through option exercises | 0 | 1 | 62 |
Proceeds from issuance of common stock through employee stock purchase plan | 105 | 44 | 11 |
Proceeds from issuance of common stock from at-the-market offerings, net of offering costs | 18,446 | 5,472 | 14,070 |
Proceeds from issuance of common stock from committed purchase agreement, net of offering costs | 0 | 0 | 15,236 |
Proceeds from issuance of common stock from underwritten follow-on public offering, net of offering costs | 48,073 | 0 | 80,646 |
Principal paid on finance lease liabilities | (394) | (66) | 0 |
Net cash provided by financing activities | 66,230 | 5,451 | 110,025 |
Net change in cash, cash equivalents and restricted cash | 12,882 | 10,810 | (14,616) |
Cash, cash equivalents and restricted cash at beginning of period | 13,146 | 2,336 | 16,952 |
Cash, cash equivalents and restricted cash at end of period | 26,028 | 13,146 | 2,336 |
Cash and cash equivalents at the end of period | 22,544 | 9,981 | 2,336 |
Restricted cash at the end of period | 3,484 | 3,165 | 0 |
Cash, cash equivalents and restricted cash at the end of period | 26,028 | 13,146 | 2,336 |
Supplemental disclosure of cash flow information: | |||
Interest paid | 172 | 54 | 0 |
Purchases of property and equipment in accounts payable | 51 | 1,194 | 0 |
Right-of-use assets obtained in exchange for lease obligation | $ 1,854 | $ 8,695 | $ 0 |
Organization, Business and Basi
Organization, Business and Basis of Presentation | 12 Months Ended |
Dec. 31, 2023 | |
Accounting Policies [Abstract] | |
Organization, Business and Basis of Presentation | 1. Organization, Business and Basis of Presentation Organization and Business We were incorporated in the state of Delaware on September 8, 2005. We are a clinical stage biotechnology company leveraging evolutionary intelligence to translate tRNA synthetase biology into new therapies for fibrosis and inflammation. tRNA synthetases are ancient, essential proteins that have evolved novel domains that regulate diverse pathways extracellularly in humans. Our discovery platform is focused on unlocking hidden therapeutic intervention points by uncovering signaling pathways driven by our proprietary library of domains derived from all 20 tRNA synthetases. Principles of Consolidation Our consolidated financial statements include our accounts and our 98 % majority-owned subsidiary in Hong Kong, Pangu BioPharma Limited (Pangu BioPharma). All intercompany transactions and balances are eliminated in consolidation. Liquidity and Financial Condition We have incurred losses and negative cash flows from operations since our inception. As of December 31, 2023, we had an accumulat ed deficit of $ 468.0 million and we expect to continue to incur net losses for the foreseeable future. As of December 31, 2023, our cash, cash equivalents, available-for-sale investments and restricted cash were $ 101.7 million. We currently have an “at-the-market” offering program (the Jefferies ATM Offering Program) through an Open Market Sale Agreement SM with Jefferies LLC (Jefferies). During the year ended December 31, 2023, we sold an aggregate of 10,530,795 shares of common stock at a weighted-average price of $ 1.82 per share for net proceeds of approximately $ 18.4 million under the Jefferies ATM Offering Program. Additionally, from January 1, 2024 through March 13, 2024, we sold an aggregate of 4,441,509 shares of common stock at a weighted-average price of $1.75 per share for net proceeds of approximately $7.6 million under the Jefferies ATM Offering Program. We believe that our current cash, cash equivalents, available-for-sale investments and restricted cash, will be sufficient to meet our anticipated cash requirements for a period of at least one year from the date of this Annual Report. We do not expect to generate any revenues from product sales unless and until we successfully complete development and obtain regulatory approval for one or more of our product candidates, which we expect will take a number of years at a minimum. If we obtain regulatory approval for any of our product candidates, we expect to incur significant commercialization expenses related to product sales, marketing, manufacturing and distribution. Accordingly, we will need to raise substantial additional capital to fund our operations. The amount and timing of our future funding requirements will depend on many factors, including the pace and results of our preclinical and clinical development efforts and the timing and nature of the regulatory approval process for our product candidates. We anticipate that we will seek to fund our operations through equity offerings, grant funding, collaborations, strategic partnerships and/or licensing arrangements, and when we are closer to commercialization of our product candidates potentially through debt financings. However, we may be unable to raise additional capital or enter into such arrangements when needed on favorable terms or at all. Our failure to raise capital or enter into such arrangements when needed would have a negative impact on our financial condition and ability to develop our product candidates. Restricted Cash As of December 31, 2023, restricted cash was approximately $ 3.5 million, which was held as a security deposit in conjunction with our corporate headquarter facility lease and financing leases as discussed further in Note 6 - Commitments and Contingencies. Use of Estimates Our consolidated financial statements are prepared in accordance with generally accepted accounting principles (GAAP). The preparation of our consolidated financial statements requires us to make estimates and assumptions that impact the reported amounts of assets, liabilities and expenses and the disclosure for these items in our consolidated financial statements and accompanying notes. The most significant estimates in our consolidated financial statements relate to the fair value of equity issuances and awards, and clinical trial and research and development expenses. Although these estimates are based on our knowledge of current events and actions we may undertake in the future, actual results may ultimately differ materially from these estimates and assumptions. Segment Reporting Operating segments are identified as components of an enterprise about which separate discrete financial information is available for evaluation by the chief operating decision-maker in making decisions regarding resource allocation and assessing performance. We view our operations and manage our business in one operating segment |
Summary of Significant Accounti
Summary of Significant Accounting Policies | 12 Months Ended |
Dec. 31, 2023 | |
Accounting Policies [Abstract] | |
Summary of Significant Accounting Policies | 2. Summary of Significant Accounting Policies Cash and Cash Equivalents and Restricted Cash Cash, cash equivalents and restricted cash consist of checking, money market and highly liquid investments that are readily convertible to cash and that have an original maturity of three months or less from date of purchase. The carrying amounts approximate fair value due to the short maturities of these instruments. Employee Retention Credit On March 27, 2020, the Coronavirus Aid, Relief, and Economic Security Act (CARES Act) was signed into law providing numerous tax incentives and other stimulus measures, including an employee retention credit (ERC), which is a refundable tax credit against certain employment taxes. The Taxpayer Certainty and Disaster Tax Relief Act of 2020 and the American Rescue Plan Act of 2021 extended and expanded the availability of the ERC. As a result of the foregoing legislation, we determined that we are eligible to claim an ERC benefit equal to 50 % of qualified wages that we paid to our employees between March 17, 2020 and December 31, 2020, and 70 % of the qualified wages that we paid to our employees between January 1, 2021 and September 30, 2021. Qualified wages are limited to $ 10,000 per employee for March 17, 2020 through December 31, 2020, and $ 10,000 per employee per calendar quarter from January 1, 2021 through September 30, 2021. Our credit was primarily derived from qualified wages during January 1, 2021 through September 30, 2021. To determine eligibility for January 1, 2021 through September 30, 2021, we compared gross receipts for each calendar quarter in 2021 to the corresponding calendar quarter in 2019 and determined that we had met the requirement for a decline in gross receipts. Accounting Standards Codification (ASC) Topic 105, Generally Accepted Accounting Principles describes the decision-making framework when no guidance exists in U.S. GAAP for a particular transaction. Specifically, ASC 105-10-05-2 instructs companies to look for guidance for a similar transaction within U.S. GAAP and apply that guidance by analogy. We accounted for the ERC by analogy to International Accounting Standards (IAS) 20, Accounting for Government Grants and Disclosure of Government Assistance, of International Financial Reporting Standards (IFRS). Under an IAS 20 analogy, a business entity would recognize the credit on a systematic basis over the periods in which the entity recognizes the payroll expenses for which the ERC is intended to compensate when there is reasonable assurance that the entity will comply with any conditions attached to the ERC and the ERC will be received. During the year ended December 31, 2023, we amended certain payroll tax filings and applied for a refund of $ 1.2 million of ERC benefits. The refund was recorded within the other receivables in our consolidated balance sheet, and as a $ 0.8 million reduction of research and development expenses and a $ 0.4 million reduction of general and administrative expenses in our consolidated statements of operations for the year ended December 31, 2023. Allowance of Credit Losses For available-for-sale securities in an unrealized loss position, we first assess whether we intend to sell, or if it is more likely than not that we will be required to sell, the security before recovery of its amortized cost basis. If either of the criteria regarding intent or requirement to sell is met, the security’s amortized cost basis is written down to fair value through earnings. For available-for-sale securities that do not meet the aforementioned criteria, we evaluate whether the decline in fair value has resulted from credit losses or other factors. In making this assessment, we consider the severity of the impairment, any changes in interest rates, market conditions, changes to the underlying credit ratings and forecasted recovery, among other factors. The credit-related portion of unrealized losses, and any subsequent improvements, are recorded in interest income through an allowance account. Any impairment that has not been recorded through an allowance for credit losses is included in other comprehensive income (loss) on the consolidated statements of operations and comprehensive loss. We elected the practical expedient to exclude the applicable accrued interest from both the fair value and amortized costs basis of our available-for-sale securities for purposes of identifying and measuring an impairment. Accrued interest receivable on available-for-sale securities is recorded within other receivables on our consolidated balance sheets. Our accounting policy is to not measure an allowance for credit loss for accrued interest receivable and to write-off any uncollectible accrued interest receivable as a reversal of interest income in a timely manner, which we consider to be in the period in which we determine the accrued interest will not be collected by us. Concentration of Credit Risk Financial instruments that potentially subject us to significant concentration of credit risk consist primarily of cash, cash equivalents, restricted cash and investment securities. We have established guidelines regarding diversification of investments and their maturities, which are designed to maintain principal and maximize liquidity. We maintain deposits in federally insured financial institutions in excess of federally insured limits. We have not experienced any losses in such accounts and we believe that we are not exposed to significant credit risk due to the financial position of the depository institutions in which those deposits are held. Property and Equipment Property and equipment are stated at cost and depreciated on a straight-line basis over the estimated useful life of the related assets (generally three to seven years ). Leasehold improvements are stated at cost and amortized on a straight-line basis over the lesser of the remaining term of the related lease or the estimated useful life of the leasehold improvements. Repairs and maintenance costs are charged to expense as incurred . Impairment of Long-Lived Assets Long-lived assets consist primarily of property and equipment and right-of-use assets (ROU) associated with our operating and financing leases. An impairment loss is recorded if and when events and circumstances indicate that assets might be impaired and the undiscounted cash flows estimated to be generated by those assets are less than the carrying amount of those assets. While our current and historical operating losses are indicators of impairment, we believe that future cash flows to be received support the carrying value of our long-lived assets and, accordingly, have no t recognized any impairment losses since inception. Accrued Expenses Accrued expenses include salaries, wages, benefits costs, consulting fees, legal and research and development costs. We have entered into contractual arrangements related to our clinical studies with clinical research organizations (CROs) and contracted development and manufacturing organizations (CDMOs) and recognize expense based on work completed and efforts expended pursuant to our contractual arrangements. We make estimates of our accrued CRO costs as of each balance sheet date based on facts and circumstances known at the time and include total trial management costs, sites activated, patients enrolled and number of patient visits. We estimate the time period over which services will be performed and the level of effort to be expended in each period. There may be instances in which payments made to our service providers including CROs and CDMOs, will temporarily exceed the level of services provided and result in a prepayment of the expense. If the actual timing of the performance of services or the level of effort varies from our estimate, we adjust the accrual or prepaid expense balance accordingly. Historically, our estimated accrued liabilities have materially approximated actual expenses incurred. Leases We determine if an arrangement is a lease at inception. Short-term leases with an initial term of 12 months or less are not recorded on our balance sheet. For long-term leases with an initial term of greater than 12 months, we recognize a right-of-use asset (ROU) and a lease liability based on the present value of future lease payments using an estimated rate of interest that we would pay to borrow equivalent funds on a collateralized basis at the lease commencement date. We determine the lease term at the commencement date by considering whether renewal options and termination options are reasonably assured of exercise. Rent expense for operating leases is recognized on a straight-line basis over the lease term and is included in operating expenses in our consolidated statements of operations. For financing leases, interest expense and amortization of the ROU is included in operating expenses in our consolidated statements of operations and variable lease payments are recorded as incurred. If a lease is modified, the modified contract is evaluated to determine whether it is or contains a lease. If a lease continues to exist, the lease modification is determined to be a separate contract when the modification grants the lessee an additional ROU that is not included in the original lease and the lease payments increase commensurate with the standalone price for the additional ROU. A lease modification that results in a separate contract will be accounted for in the same manner as a new lease. For a modification that is not a separate contract, we reassess the lease classification using the modified terms and conditions and the facts and circumstances as of the effective date of the modification and recognize the amount of the remeasurement of the lease liability for the modified lease as an adjustment to the corresponding lease ROU asset. Our ROU assets consist of non-cancelable operating leases and financing leases. Non-cancelable operating leases consist of leases for our corporate headquarters and additional laboratory space. Financing leases consist of leases for various research and development and information technology equipment. We do not separate lease and non-lease components for our long-term leases. Revenue Recognition We evaluate our agreements under ASC Topic 606, Revenue from Contracts with Customers and ASC Topic 808, Collaborative Arrangements . We recognize revenue when we transfer promised goods or services to customers in an amount that reflects the consideration to which we expect to be entitled in exchange for those goods or services. In determining the appropriate amount of revenue to be recognized as we fulfill our obligations under our agreement, we perform the following steps: (i) identification of the promised goods or services in the contract; (ii) determination of whether the promised goods or services are performance obligations including whether they are distinct in the context of the contract; (iii) measurement of the transaction price, including the constraint on variable consideration; (iv) allocation of the transaction price to the performance obligations; and (v) recognition of revenue when (or as) we satisfy each performance obligation. As part of the accounting for these arrangements, we must develop assumptions that require judgment to determine the stand-alone selling price for each performance obligation identified in the contract. We use key assumptions to determine the stand-alone selling price, which may include forecasted revenues, development timelines, reimbursement rates for personnel costs, discount rates and probabilities of technical and regulatory success. We recognize revenue in one of two ways, over time or at a point in time. We recognize revenue over time when we are executing on our performance obligation over time and our partner receives benefit over time. For example, we recognize revenue over time when we provide research and development services. We recognize revenue at a point in time when we transfer control of a distinct performance obligation to our partner. For example, if a license to our intellectual property is determined to be distinct from the other performance obligations identified in the arrangement, we recognize revenues from non-refundable, up-front fees allocated to the license when the license is transferred to the licensee and the licensee is able to use and benefit from the license. Research and Development Costs Research and development costs are expensed as incurred. Research and development costs include: salaries and employee-related expenses, including stock-based compensation and benefits for personnel in research and product development functions; costs associated with conducting our preclinical, development and regulatory activities, including fees paid to third-party professional consultants, service providers and our scientific, therapeutic and clinical advisors; costs to acquire, develop and manufacture preclinical study and clinical trial materials; costs incurred under clinical trial agreements with CROs and investigative sites; costs for laboratory supplies; payments related to licensed products and technologies; allocated facilities and information technology costs; and depreciation. Patent Costs Costs related to filing and pursuing patent applications are recorded as general and administrative expense and expensed as incurred since recoverability of such expenditures is uncertain. Stock-Based Compensation We evaluate our stock-based compensation arrangements under ASC Topic 718, Compensation – Stock Compensation. Stock-based compensation expense represents the grant date fair value of employee stock option and restricted stock unit grants recognized as expense over the requisite service period of the awards (usually the vesting period) on a straight-line basis. We estimate fair value of stock option grants using the Black-Scholes option pricing model. We estimate the fair value using assumptions, including the risk-free interest rate, the expected volatility of a peer group of similar companies, the expected term of the awards and the expected dividend yield. These estimates involve inherent uncertainties and the application of management’s judgment. If factors change and different assumptions are used, our stock-based compensation expense could be materially different in the future. Income Taxes We account for income taxes under the asset and liability method, which requires the recognition of deferred tax assets and liabilities for the expected future tax consequences of events that have been included in the consolidated financial statements. Under this method, deferred tax assets and liabilities are determined on the basis of the differences between the consolidated financial statements and tax basis of assets and liabilities using enacted tax rates in effect for the year in which the differences are expected to reverse. The effect of a change in tax rates on deferred tax assets and liabilities is recognized as income in the period that includes the enactment date. We recognize net deferred tax assets to the extent that we believe these assets are more likely than not to be realized. In making such a determination, we consider all available positive and negative evidence, including future reversals of existing taxable temporary differences, projected future taxable income, tax-planning strategies and results of recent operations. If we determine that we would be able to realize the deferred tax assets in the future in excess of their net recorded amount, we would make an adjustment to the deferred tax asset valuation allowance, which would reduce the provision for income taxes. We record uncertain tax positions on the basis of a two-step process whereby (1) we determine whether it is more likely than not that the tax positions will be sustained on the basis of the technical merits of the position and (2) for those tax positions that meet the more-likely-than-not recognition threshold, we recognize the largest amount of tax benefit that is more than 50 % likely to be realized upon ultimate settlement with the related tax authority. We recognize interest and penalties related to unrecognized tax benefits within income tax expense. Any accrued interest and penalties are included within the related tax liability. Net Loss Per Share Basic net loss per share is calculated by dividing the net loss attributable to common stockholders by the weighted average number of common shares outstanding for the period, without consideration for common stock equivalents. Diluted net loss per share attributable to common stockholders is calculated by dividing the net loss attributable to common stockholders by the weighted average number of common stock and common stock equivalents outstanding for the period determined using the treasury-stock method. Dilutive common stock equivalents are comprised of convertible preferred stock, warrants for common stock, options and restricted stock units outstanding under our stock option plans and inducement grants and estimated shares to be purchased under our 2015 Employee Stock Purchase Plan (the 2015 ESPP). For all periods presented, there is no difference in the number of shares used to calculate basic and diluted shares outstanding due to our net loss position. Potentially dilutive securities not included in the calculation of diluted net loss per share because to do so would be anti-dilutive are as follows (in common share equivalents): Years Ended December 31, 2023 2022 2021 Common stock warrants 5,864 13,760 13,760 Common stock options and restricted stock units 4,020,154 3,077,608 1,420,050 Employee stock purchase plan 41,862 34,588 2,045 Total 4,067,880 3,125,956 1,435,855 The following table summarizes our net loss per share (in thousands, except per share data): Years Ended December 31, 2023 2022 2021 Numerator: Net loss attributable to aTyr Pharma, Inc. $ ( 50,389 ) $ ( 45,338 ) $ ( 33,768 ) Denominator: Shares used in computing net loss per share, basic and diluted 53,606,488 28,419,569 19,080,878 Net loss per share - basic and diluted $ ( 0.94 ) $ ( 1.60 ) $ ( 1.77 ) Recent Accounting Pronouncements In June 2016, the Financial Accounting Standards Board issued Accounting Standards Update (ASU) No. 2016-13, Financial Instruments – Credit Losses (Topic 326), to provide financial statement users with more decision-useful information about the expected credit losses on financial instruments and other commitments to extend credit held by a reporting entity at each reporting date. To achieve this objective, the amendments in Topic 326 replace the incurred loss impairment methodology in current U.S. GAAP with a methodology that reflects expected credit losses and requires consideration of a broader range of reasonable and supportable information to inform credit loss estimates. Topic 326 is effective for fiscal years beginning after December 15, 2022, including interim periods within those fiscal years for smaller reporting companies. We adopted Topic 326 on January 1, 2023 . The adoption did not have a material impact on our consolidated financial statements. In December 2023, the FASB, issued ASU 2023-09, Improvements to Income Tax Disclosures, which requires 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 fiscal years beginning after December 15, 2024, with early adoption permitted. We are currently evaluating the disclosure requirements related to the new standard. |
Fair Value Measurements
Fair Value Measurements | 12 Months Ended |
Dec. 31, 2023 | |
Fair Value Disclosures [Abstract] | |
Fair Value Measurements | 3. Fair Value Measurements The carrying amounts of cash equivalents, prepaid and other assets, accounts payable and accrued liabilities are considered to be representative of their respective fair values because of the short-term nature of those instruments. Investment securities are recorded at fair value. The accounting guidance defines fair value, establishes a consistent framework for measuring fair value and expands disclosure for each major asset and liability category measured at fair value on either a recurring or nonrecurring basis. Fair value is defined as an exit price, representing the amount that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants. As such, fair value is a market-based measurement that should be determined based on assumptions that market participants would use in pricing an asset or liability. As a basis for considering such assumptions, the accounting guidance establishes a three-tier fair value hierarchy, which prioritizes the inputs used in measuring fair value as follows: Level 1: Observable inputs such as quoted prices in active markets. Level 2: Inputs, other than the quoted prices in active markets that are observable either directly or indirectly. Level 3: Unobservable inputs in which there is little or no market data, which require the reporting entity to develop its own assumptions. Financial assets measured at fair value on a recurring basis consist of investment securities. Investment securities are recorded at fair value, defined as the exit price in the principal market in which we would transact, representing the amount that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants. Level 2 securities are valued using quoted market prices for similar instruments, non-binding market prices that are corroborated by observable market data, or discounted cash flow techniques and include our investments in commercial paper, corporate debt securities and U.S. government agencies. We have no financial liabilities measured at fair value on a recurring basis. None of our non-financial assets and liabilities are recorded at fair value on a non-recurring basis. No transfers between levels have occurred during the periods presented. Assets measured at fair value on a recurring basis are as follows (in thousands): Fair Value Measurements Using Total Quoted Prices in Markets Identical Significant Significant As of December 31, 2023 Assets: Current: Cash equivalents $ 21,626 $ 21,626 $ — $ — Available-for-sale investments: Commercial paper 31,198 — 31,198 — Corporate debt securities 27,578 — 27,578 — U.S. government agencies 16,846 — 16,846 — Total available-for-sale investments 75,622 — 75,622 — Total assets measured at fair value $ 97,248 $ 21,626 $ 75,622 $ — Fair Value Measurements Using Total Quoted Prices in Markets Identical Significant Significant As of December 31, 2022 Assets: Current: Cash equivalents $ 8,585 $ 8,585 $ — $ — Available-for-sale investments: Commercial paper 28,074 — 28,074 — Corporate debt securities 26,094 — 26,094 — Municipal bonds 1,997 — 1,997 — Total available-for-sale investments 56,165 — 56,165 — Total assets measured at fair value $ 64,750 $ 8,585 $ 56,165 $ — As of December 31, 2023 and 2022, available-for-sale investments are detailed as follows (in thousands): December 31, 2023 Contractual Maturity Gross Gross Gross Market Value Available-for-sale investments: Commercial paper Within 1 year $ 31,198 $ 14 $ ( 14 ) $ 31,198 Corporate debt securities Within 2 years 27,607 12 ( 41 ) 27,578 U.S. government agencies Within 1 year 16,841 26 ( 21 ) 16,846 $ 75,646 $ 52 $ ( 76 ) $ 75,622 December 31, 2022 Contractual Maturity Gross Gross Gross Market Value Available-for-sale investments: Commercial paper Within 1 year $ 28,121 $ — $ ( 47 ) $ 28,074 Corporate debt securities Within 2 years 26,401 — ( 307 ) 26,094 Municipal bonds Within 1 year 2,026 — ( 29 ) 1,997 $ 56,548 $ — $ ( 383 ) $ 56,165 We evaluate our available-for-sale debt securities for credit losses when the amortized cost basis exceeds fair value. The credit-related portion of unrealized losses, and any subsequent improvements, are recorded in interest income through an allowance account. Unrealized gains and losses that are not credit-related are included in accumulated other comprehensive income (loss). When evaluating an investment for impairment, we review factors such as the severity of the impairment, changes in underlying credit ratings, our intent to sell or the likelihood that we would be required to sell the investment before its anticipated recovery in market value and the probability that the scheduled cash payments will continue to be made. Based on our evaluation, we did not record allowance for credit losses in the consolidated statement of operations during the year ended December 31, 2023. As of December 31, 2023, all available-for-sale investments had a variety of effective maturity dates of less than two years . As of December 31, 2023, $ 74.6 million of our short-term investments had maturities less than one year and $ 1.0 million had maturities greater than one year. As of December 31, 2023, 19 out of 25 available-for-sale investments were in a gross unrealized loss position of which one available-for-sale investment with a market value of $ 2.0 million was in such position for greater than 12 months . As of December 31, 2023 and 2022, accrued interest receivable on available-for-sale securities was $ 0.3 million and $ 0.2 million, respectively. |
License, Collaboration and Othe
License, Collaboration and Other Agreements | 12 Months Ended |
Dec. 31, 2023 | |
License Agreement [Abstract] | |
License, Collaboration and Other Agreements | 4. License, Collaboration and Other Agreements Kyorin Pharmaceutical Co., Ltd. In January 2020, we entered into a collaboration and license agreement (Kyorin Agreement) with Kyorin Pharmaceutical Co., Ltd. (Kyorin) for the development and commercialization of efzofitimod for the treatment of interstitial lung disease (ILD) in Japan. Under the Kyorin Agreement, Kyorin received an exclusive right to develop and commercialize efzofitimod in Japan for all forms of ILD, and is obligated to fund all research, development, regulatory, marketing and commercialization activities in Japan. In 2020, Kyorin conducted and funded a Phase 1 clinical trial of efzofitimod (known as KRP-R120 in Japan). The Phase 1 clinical trial was a placebo-controlled clinical trial to evaluate the safety, pharmacokinetics (PK) and immunogenicity of efzofitimod in 32 healthy Japanese male volunteers. Efzofitimod was observed to be generally well-tolerated with no drug-related serious adverse events, and PK findings were consistent with previous studies of efzofitimod. Kyorin is also participating in the EFZO-FIT study as the local sponsor in Japan. In February 2023, Kyorin dosed the first patient in Japan in the EFZO-FIT study which triggered a $ 10.0 million milestone payment to us. To date, the Kyorin Agreement has generated $ 20.0 million in upfront and milestone payments to us and we are eligible to receive up to an additional $ 155.0 million in the aggregate upon achievement of certain development, regulatory and sales milestones, as well as tiered royalties on any net sales in Japan. Either party may terminate the Kyorin Agreement in the event that the other party breaches the agreement and fails to cure the breach, becomes insolvent or challenges certain of the intellectual property rights licensed under the agreement. We assessed our license and collaboration with Kyorin in accordance with Topic 606 and concluded that Kyorin is a customer. We identified the following performance obligations under the Kyorin Agreement: 1) the license of efzofitimod for ILD in Japan; and 2) free clinical trial material for Kyorin’s Phase 1 clinical trial. Kyorin is participating in the EFZO-FIT study and received approval from the Pharmaceuticals and Medical Devices Agency (PMDA) to commence the EFZO-FIT study in Japan in December 2022. Additionally, in February 2023, Kyorin dosed the first patient in Japan in the EFZO-FIT study which triggered a $ 10.0 million milestone payment to us. We recognized this $ 10.0 million milestone payment as revenue during the year ended December 2022, as we determined the milestone became probable of achievement with Kyorin having scheduled site visits for patient screenings by that time. We received this $ 10.0 million milestone payment in February 2023. During the year ended December 31, 2023, we recognized $ 0.4 million in collaboration revenue from Kyorin for drug product material sold to Kyorin for the Japan portion of the EFZO-FIT study. The remaining milestones and royalty payments under the Kyorin Agreement are variable consideration. Since the milestone payments are binary in nature, we will use the “most-likely” method to evaluate whether the milestones should be included as revenue. We will constrain these amounts until they become probable of being achieved. The royalties are dependent on future sales by Kyorin which are at the full discretion of Kyorin. Accordingly, we will apply a constraint to these amounts until the future sale sales have occurred. |
Balance Sheet Details
Balance Sheet Details | 12 Months Ended |
Dec. 31, 2023 | |
Balance Sheet Details [Abstract] | |
Balance Sheet Details | 5. Balance Sheet Details Prepaid expenses consist of the following (in thousands): December 31, 2023 2022 Prepaid clinical and research expense $ 1,475 $ 334 Prepaid manufacturing expenses 125 2,049 Other prepaid expenses 790 567 $ 2,390 $ 2,950 Property and equipment consist of the following (in thousands): December 31, 2023 2022 Computer and office equipment $ 448 $ 620 Scientific and laboratory equipment 4,051 4,379 Tenant improvements 5,653 4,414 10,152 9,413 Less accumulated depreciation and amortization ( 4,621 ) ( 6,354 ) $ 5,531 $ 3,059 During the years ended December 31, 2023, 2022 and 2021, depreciation expense was $ 0.6 million, $ 0.2 million and $ 0.5 million, respectively. Accrued expenses consist of the following (in thousands): December 31, 2023 2022 Accrued salaries, wages and benefits $ 2,706 $ 2,781 Accrued clinical and manufacturing 7,753 5,151 Other accrued expenses 1,100 1,930 $ 11,559 $ 9,862 |
Commitments and Contingencies
Commitments and Contingencies | 12 Months Ended |
Dec. 31, 2023 | |
Commitments and Contingencies Disclosure [Abstract] | |
Commitments and Contingencies | 6. Commitments and Contingencies Operating Leases Corporate Headquarters Facility Lease In May 2022, we entered into a lease (the Lease) with San Diego Creekside, LLC (Landlord), as lessor, pursuant to which we agreed to lease from Landlord approximately 23,696 rentable square feet (subject to increase pursuant to the terms of the Lease) of office and laboratory space. The term of the lease (the Lease Term) commenced on March 20, 2023 (the Lease Commencement Date) and will continue for 124 months from the Lease Commencement Date. We also have one option to extend the Lease Term for five years . Base rent during such extension period would be at the fair market rent for the Premises (as that term is defined in the Lease). Under the terms of the Lease, the base rent during the first 12 months of the Lease Term will be $ 5.75 per square foot of rentable area per month, subject to certain upward adjustments of approximately 3.0 % annually. We are entitled to an allowance of up to $ 5.3 million for tenant improvements of which as of December 31, 2023 we had received $ 5.0 million, and we received the remaining $ 0.3 million in February 2024. We provided a $ 0.7 million security deposit in the form of a letter of credit which is included in restricted cash as of December 31, 2023. During the second quarter of 2023, additional common area amenities were completed by the Landlord which provided us with access to approximately 1,500 additional rentable square feet. As a result, our base rent increased for this additional rentable square feet at the same monthly base rent per rentable square foot as contemplated in the Lease. Previous Corporate Headquarters Facility Lease Our operating lease for our previous corporate headquarters was subject to base lease payments, additional charges for common area maintenance and other costs and it expired in May 2023. Future minimum payments under the facility lease and reconciliation to the operating lease liability as of December 31, 2023 were as follows (in thousands): Operating Leases 2024 $ 1,949 2025 1,975 2026 1,923 2027 1,942 2028 and thereafter 11,968 Less: Amount representing interest ( 6,289 ) Present value of lease payments 13,468 Less: Current portion of operating lease liability ( 831 ) Less: Tenant improvement allowance not yet received ( 298 ) Long-term operating lease liability, net of current portion $ 12,339 Operating lease expense was $ 1.9 million, $ 1.5 million and $ 1.0 million for the years ended December 31, 2023, 2022 and 2021, respectively. As of December 31, 2023 and 2022, the weighted average remaining lease term was 9.4 years and 9.9 years, respectively. As of December 31, 2023 and 2022, the weighted average discount rate for each period was 8.8 %. Financing Leases In April 2022, we entered into a master financing lease agreement to lease various research and development and information technology equipment over a 48-month term. Future minimum payments under the financing lease and reconciliation to the financing lease liability as of December 31, 2023 were as follows (in thousands): Financing Leases 2024 $ 634 2025 634 2026 676 2027 264 Less: Amount representing interest ( 283 ) Present value of lease payments 1,925 Less: Current portion of financing lease liability ( 497 ) Long-term financing lease liability, net of current portion $ 1,428 As of December 31, 2023 and 2022, the weighted-average remaining lease term was 3.0 years and 3.7 years, respectively and the weighted-average discount rate was 8.3 % and 7.9 %, respectively. We provided a $ 2.7 million deposit to be held as collateral for the leased equipment, and this deposit is included in restricted cash as of December 31, 2023. |
Stockholders' Equity
Stockholders' Equity | 12 Months Ended |
Dec. 31, 2023 | |
Equity [Abstract] | |
Stockholders' Equity | 7. Stockholders’ Equity Underwritten Follow-On Public Offerings In February 2023, we completed an underwritten follow-on public offering of 23,125,000 shares of our common stock, including the partial exercise of the underwriters’ option to purchase additional shares, at a price to the public of $ 2.25 per share. The total net proceeds from the offering were approximately $ 48.1 m illion, after deducting underwriting discounts, commissions and offering expenses payable by us. In September 2021, we completed an underwritten follow-on public offering of 10,781,250 shares of our common stock, including the full exercise of the underwriters’ option to purchase additional shares, at a price to the public of $ 8.00 per share. The total net proceeds from the offering were approximately $ 80.6 million, after deducting underwriting discounts, commissions and offering expenses payable by us. At-the-Market Offering Programs In April 2022, we entered into an Open Market Sale Agreement SM with Jefferies implementing the Jefferies ATM Offering Program, pursuant to which we may offer and sell, from time to time and at our option, up to an aggregate of $ 65.0 million of shares of our common stock through Jefferies, acting as sales agent. Jefferies is entitled to a fixed commission rate of up to 3.0 % of the gross sales proceeds of shares sold under the Jefferies ATM Offering Program. During the year ended December 31, 2022, we sold an aggregate of 1,421,627 shares of common stock at a weighted-average price of $ 3.09 per share for net proceeds of approximately $ 4.0 million under the Jefferies ATM Offering Program. During the year ended December 31, 2023, we sold an aggregate of 10,530,795 shares of common stock at a weighted-average price of $ 1.82 per share for net proceeds of approximately $ 18.4 million under the Jefferies ATM Offering Program. In March 2021, we entered into a Capital on Demand TM Sales Agreement with JonesTrading Institutional Services LLC (JonesTrading) for an at-the-market offering program (the JonesTrading ATM Offering Program), pursuant to which we were entitled to sell from time to time, at our option, up to an aggregate of $ 25.0 million of shares of our common stock through JonesTrading, as sales agent or principal. JonesTrading was entitled to a commission at a fixed rate of up to 3.0 % of the gross proceeds. During 2021, we sold an aggregate of 986,267 shares of common stock at a weighted-average price of $ 4.75 per share for net proceeds of $ 4.4 million under the JonesTrading ATM Offering Program. In April 2022, we terminated the JonesTrading ATM Offering Program. During 2022 and prior to termination in April 2022, we sold an aggregate of 260,455 shares of common stock at a weighted-average price of $ 6.07 per share for net proceeds of approximately $ 1.5 million under the JonesTrading ATM Offering Program. In May 2019, we entered into a sales agreement with H.C. Wainwright & Co., LLC (Wainwright) for an ATM Offering Program (the Wainwright ATM Offering Program) under which we could offer and sell shares of our common stock having an aggregate offering price of up to $ 10.0 million. In November 2020, we amended our sales agreement with Wainwright to increase the amount of the ATM Offering Program to $ 20.0 million. Wainwright was entitled to a commission at a fixed commission rate equal to 3 % of the gross proceeds. In March 2021, the ATM Offering Program with Wainwright automatically terminated upon the issuance and sale of all of the shares having an aggregate offering price of $ 20.0 million. Prior to the termination of the sales agreement with Wainwright, in 2021, we sold an aggregate of 1,988,254 shares of common stock at an average price of $ 4.99 per share for net proceeds of $ 9.6 million. Purchase Agreement In September 2020 , we entered into a common stock purchase agreement (the Purchase Agreement) with Aspire Capital Fund, LLC (Aspire Capital), which provided that, upon the terms and subject to the conditions and limitations set forth therein, Aspire Capital was committed to purchase up to an aggregate of $ 20.0 million of shares of our common stock at our request from time to time during the 30 month term of the Purchase Agreement. In 2021, we sold an aggregate of 3,000,000 shares of common stock at a weighted-avera ge price of $ 5.09 per share for net proceeds of $ 15.2 million under the Purchase Agreement. There were no issuances or sales under the Purchase Agreement during the years ended December 31, 2023 and December 31, 2022, respectively, and this agreement was terminated on March 11, 2023. 2014 Stock Plan We adopted a stock option plan in 2007 (the 2007 Plan), which was subsequently amended, restated and renamed in July 2014 (the 2014 Plan) to provide for the incentive stock options, nonstatutory stock options, stock and rights to purchase restricted stock to eligible recipients. Recipients of incentive stock options are eligible to purchase shares of our common stock at an exercise price equal to no less than the estimated fair market value of such stock on the date of grant. The maximum term of options under the 2014 Plan is ten years . Options granted generally vest over four years . We ceased granting under the 2014 Plan after our IPO in May 2015. Shares underlying any awards under the 2014 Plan that are forfeited, canceled, reacquired by us prior to vesting, satisfied without the issuance of stock or otherwise terminated (other than by exercise) will be added to shares available for issuance under our 2015 Stock Option and Incentive Plan (the 2015 Stock Plan), which became effective in May 2015. 2015 Stock Plan Total shares available for issuance under the 2015 Stock Plan as of December 31, 2023 were 3,964,555 . Shares underlying any awards under the 2015 Stock Plan that are forfeited, canceled, reacquired by us prior to vesting, satisfied without the issuance of stock or otherwise terminated (other than by exercise) will be added to shares available for issuance under the 2015 Stock Plan. The maximum term of options granted under 2015 Stock Plan is ten years . For an initial grant to an employee, 25 % of the options generally vest on the first anniversary of the original vesting date, with the balance vesting monthly over the remaining three years. For subsequent grants to an employee, the options generally vest monthly over a four-year term. Inducement Plan In March 2022, our board of directors approved and adopted our 2022 Inducement Plan (our Inducement Plan). Awards granted under our Inducement Plan are in accordance with Nasdaq Listing Rule 5635(c)(4). A total of 300,000 shares of our common stock were initially reserved for the issuance under our Inducement Plan. The maximum term of options granted under our Inducement Plan is ten years . Each option vests over a period of four years , with 25 % of the shares vesting on the one-year anniversary of the applicable vesting commencement date and the remaining 75 % vesting in equal monthly installments over three years , thereafter, subject to continuous employment. During the year ended December 31, 2023, we granted nonstatutory stock options under our Inducement Plan to purchase an aggregate of 23,400 shares of our common stock, with a weighted-average exercise price of $ 2.26 per share as inducement awards to new employees. 2015 Employee Stock Purchase Plan As of December 31, 2023, total shares reserved for issuance under the 2015 ESPP were 727,311 . Stock-based Compensation Stock Options Stock option activity is summarized as follows: Number of Weighted- Weighted Aggregate Outstanding as of December 31, 2022 2,956,170 $ 7.45 Granted 1,112,885 $ 2.21 Canceled/forfeited/expired ( 112,228 ) $ 6.42 Outstanding as of December 31, 2023 3,956,827 $ 6.00 7.94 $ — The assumptions used in the Black-Scholes option pricing model to determine the fair value of the employee stock option grants were as follows: Years Ended December 31, 2023 2022 2021 Expected term (in years) 5.51 – 6.09 5.98 – 6.08 5.50 – 6.08 Risk-free interest rate 3.58 % – 4.5 % 1.7 % – 4.2 % 0.6 % – 1.3 % Expected volatility 81.5 % – 83.0 % 84.2 % – 86.5 % 86.3 % – 104.8 % Expected dividend yield 0.0 % 0.0 % 0.0 % The assumptions used in the Black-Scholes option pricing model to determine the fair value of the ESPP offering were as follows: Years Ended December 31, 2023 2022 2021 Expected term (in years) 0.50 0.50 0.50 Risk-free interest rate 4.54 % – 5.38 % 0.06 % – 4.54 % 0.04 % – 0.12 % Expected volatility 40.9 % – 58.5 % 51.9 % – 95.9 % 89.7 % – 108.12 % Expected dividend yield 0.0 % 0.0 % 0.0 % Expected term . The expected term represents the period of time that options are expected to be outstanding. Because we do not have sufficient history of exercise behavior, we determine the expected life assumption using the simplified method, which is an average of the contractual term of the option and its vesting period. Risk-free interest rate. We base the risk-free interest rate assumption on the U.S. Treasury’s rates for U.S. Treasury zero-coupon bonds with maturities similar to those of the expected term of the award being valued. Expected volatility. The expected volatility assumption is based on our historical volatility as well as the volatilities of a peer group of similar companies whose share prices are publicly available. The peer group was developed based on companies in the biotechnology industry. Expected dividend yield. We base the expected dividend yield assumption on the fact that we have never paid cash dividends and have no present intention to pay cash dividends. Restricted Stock Units Occasionally, we grant restricted stock units to employees. The fair value of restricted stock is determined by the closing price of our common stock reported on the Nasdaq Capital Market on the date of grant. Restricted stock unit activity is summarized as follows: Number of Outstanding Weighted-Average Balance as of December 31, 2022 121,438 $ 5.09 Released ( 58,111 ) $ 4.69 Balance as of December 31, 2023 63,327 $ 5.45 The allocation of stock-based compensation for all options, including performance options with market condition and restricted stock units is as follows (in thousands): Years Ended December 31, 2023 2022 2021 Research and development $ 600 $ 528 $ 295 General and administrative 2,000 1,626 1,319 Total stock-based compensation expense $ 2,600 $ 2,154 $ 1,614 The weighted-average grant date fair value per share of stock options granted by us, during the years ended December 31, 2023, 2022 and 2021 was $ 1.59 , $ 2.49 and $ 3.82 , respectively. The total grant date fair value of restricted stock units granted by us during the years ended December 31, 2023, 2022, and 2021 was approximately $ 0 , $ 597,000 and $ 16,000 , respectively. The aggregate intrinsic value of stock options exercised during the years ended December 31, 2023, 2022 and 2021 was approximately $ 0 , $ 1,000 and $ 80,000 , respectively. The fair value of restricted stock units released during the years ended December 31, 2023, 2022 and 2021 was approximately $ 123,875 , $ 6,000 and $ 31,000 , respectively. As of December 31, 2023, total unrecognized share-based compensation expense related to unvested stock options and restricted stock units was approximately $ 4.6 million and $ 0.2 million , respectively. As of December 31, 2023, these unrecognized costs for options and restricted stock units are expected to be recognized ratably over a weighted-average period of approximately 2.3 years and 2.0 years, respectively. Warrants Warrants outstanding for the purchase of common stock as of December 31, 2023 were as follows: Number Exercise Price Expiration Outstanding Per Share Date 2,978 $ 50.37 June 2024 2,886 $ 51.98 December 2024 5,864 Common Stock Reserved for Future Issuance Common stock reserved for future issuance was as follows: December 31, 2023 Common stock warrants 5,864 Common stock options and restricted stock units 4,020,154 Shares available under the 2015 equity incentive plan 3,964,555 Shares available under the 2022 inducement plan 95,367 Shares available under the employee stock purchase plan 727,311 8,813,251 |
Income Tax
Income Tax | 12 Months Ended |
Dec. 31, 2023 | |
Income Tax Disclosure [Abstract] | |
Income Tax | 8. Income Tax Pretax losses were generated by both domestic and foreign operations as follows (in thousands): Years Ended December 31, 2023 2022 2021 United States $ ( 49,967 ) $ ( 45,086 ) $ ( 33,316 ) Foreign ( 428 ) ( 254 ) ( 458 ) Worldwide pre-tax loss $ ( 50,395 ) $ ( 45,340 ) $ ( 33,774 ) For the years ended December 31, 2023, 2022, and 2021, we did no t record a provision for income taxes due to a full valuation allowance against our deferred taxes. A reconciliation of the expected statutory federal income tax provision to the actual income tax provision is summarized as follows (in thousands): Years Ended December 31, 2023 2022 2021 Expected income taxes benefit at federal statutory rate $ ( 10,583 ) $ ( 9,521 ) $ ( 7,093 ) State income taxes, net of federal benefit ( 2,171 ) ( 380 ) ( 2,313 ) Permanent items and other 172 438 592 Stock compensation 91 44 90 Research credits ( 5,336 ) ( 4,415 ) ( 1,253 ) Unrecognized tax benefits 5,209 2,454 500 Foreign rate differential 19 11 21 Change in tax rate ( 5 ) 34 52 Change in valuation allowance 12,604 11,335 9,404 Income tax (benefit) expense $ — $ — $ — Deferred income taxes are provided for temporary differences in recognizing certain income and expense items for financial and tax reporting purposes. The deferred tax assets consisted primarily of the income tax benefits from net operating loss (NOL) carryforwards, research and development credits and capitalized research and development expenses, along with other accruals and reserves. Valuation allowances of $ 108.0 m illion and $ 95.5 million as of December 31, 2023 and 2022, respectively, have been recorded to offset deferred tax assets as realization of such assets does not meet the more-likely-than-not threshold under ASC 740, Accounting for Income Taxes . Significant components of our deferred tax assets are summarized as follows (in thousands): December 31, 2023 2022 Deferred tax assets: Net operating loss carryforwards $ 60,090 $ 52,752 Capitalized research and development expenses 25,922 22,576 Research credits and other state credits 18,246 16,021 Intangible assets 1,093 1,278 Reserve and accruals 522 596 Share-based compensation expense 1,821 1,628 Lease liability 1,709 2,157 Total tax assets 109,403 97,008 Valuation allowance ( 107,989 ) ( 95,484 ) Total deferred tax assets $ 1,414 $ 1,524 Deferred tax liabilities: Right of use lease assets ( 1,414 ) ( 1,524 ) Total deferred tax liabilities ( 1,414 ) ( 1,524 ) Net deferred tax assets $ — $ — The Tax Cuts and Jobs Act of 2017 requires taxpayers to capitalize and amortize research and development (R&D) expenditures under section 174 for tax years beginning after December 31, 2021. This rule was effective at the beginning of 2022 which resulted in a capitalization of R&D costs of approximately $ 44.2 million and $ 38.8 million during the years ended December 31, 2023 and 2022, respectively. We will amortize these costs for tax purposes over 5 years if the R&D was performed in the U.S. and over 15 years if the R&D was performed outside the U.S. As of December 31, 2023, we had federal NOL carryforwards of approximately $ 257.4 million, with $ 144.9 million of NOLs generated after December 31, 2017 carrying forward indefinitely and $ 112.5 million of NOLs that will begin to expire in 2025 . NOL carryforwards generated after January 1, 2018 are subject to an 80% of taxable income limitation in accordance with the Tax Cuts and Jobs Act of 2017. We had state net operating loss carryforwards of approximately $ 225.3 million, and foreign net operating loss carryforwards of $ 9.4 million. The state net operating losses began to expire in 2025 . The foreign net operating losses carry over indefinitely. As of December 31, 2023, we had federal and state research and development credit carryforwards of approximately $ 9.3 million and $ 5.8 million, respectively, which begin to expire in 2026 for both federal and state purposes. We had $18 .4 million of federal Orphan Drug Credits as of December 31, 2023, which will begin to expire in 2035 . Utilization of the domestic NOL and research and development credit carryforwards may be subject to a substantial annual limitation due to ownership change limitations that may have occurred or that could occur in the future, as required by Sections 382 and 383 of the Internal Revenue Code of 1986, as amended (the Code), as well as similar state and foreign provisions. These ownership changes may limit the amount of NOL and research and development credit carryforwards that can be utilized annually to offset future taxable income and tax, respectively. In general, an “ownership change” as defined by Section 382 of the Code results from a transaction or series of transactions over a three-year period resulting in an ownership change of more than 50 percentage points of the outstanding stock of a company by certain stockholders. Since the Company’s formation, we raised capital through the issuance of capital stock on several occasions which on its own or combined with the purchasing stockholders’ subsequent disposition of those shares, has resulted in such an ownership change, and could result in an ownership change in the future. Upon the occurrence of an ownership change under Section 382 as outlined above, utilization of the NOL and research and development credit carryforwards become subject to an annual limitation under Section 382 of the Code, which is determined by first multiplying the value of our stock at the time of the ownership change by the applicable long-term, tax-exempt rate, which could be subject to additional adjustments. Any limitation may result in expiration of a portion of our NOL or research and development credit carryforwards before utilization. Due to the existence of the valuation allowance, any impact to the NOL and research and development tax credit carryforwards from Section 382 analysis will be offset by a corresponding adjustment to valuation allowance, resulting in no tax provision impact. We recognize a tax benefit from an uncertain tax position when it is more likely than not that the position will be sustained upon examination, including resolutions of any related appeals or litigation processes, based on the technical merits. Income tax positions must meet a more-likely-than-not recognition threshold to be recognized. Our practice is to recognize interest and penalties related to income tax matters in income tax expense. We had no accrual for interest and penalties on our balance sheet and had not recognized interest or penalties in the consolidated statements of operations for the years ended December 31, 2023, 2022 and 2021. Due to the existence of the valuation allowance, future changes in unrecognized tax benefits will not impact our effective tax rate. Uncertain tax positions are evaluated based upon the facts and circumstances that exist at each reporting period. Subsequent changes in judgment based upon new information may lead to changes in recognition, derecognition, and measurement. Adjustments may result, for example, upon resolution of an issue with the taxing authorities, or expiration of a statute of limitations barring an assessment for an issue. The activity related to our unrecognized tax benefits is summarized as follows (in thousands): December 31, 2023 2022 2021 Balance as of beginning of year $ 25,145 $ 22,232 $ 21,707 Increase (decrease) related to prior year tax positions ( 483 ) ( 48 ) ( 9 ) Increase related to current year tax positions 5,416 2,961 534 Balance as of end of year $ 30,078 $ 25,145 $ 22,232 We do no t anticipate that the amount of unrecognized tax benefits as of December 31, 2023 will change within the next twelve months. We are subject to taxation in the United States, Hong Kong and state jurisdictions. Our tax years from inception are subject to examination by the United States, Hong Kong and various state authorities due to carry forward of unutilized NOLs and research and development credits. |
Employee Benefits
Employee Benefits | 12 Months Ended |
Dec. 31, 2023 | |
Retirement Benefits [Abstract] | |
Employee Benefits | 9. Employee Benefits 401(k) Plan We maintain a defined contribution 401(k) plan available to eligible employees. Employee contributions are voluntary and are determined on an individual basis, limited to the maximum amount allowable under federal tax regulations. In April 2015 , our board of directors approved a policy, beginning on June 1, 2015 , to match employee contributions equal to 50 % of the participant’s contribution of up to a maximum of 6 % of the participant’s annual salary. We made discretionary contributions totaling $ 0.2 million during each of the years ended December 31, 2023, 2022 and 2021. |
Subsequent Events
Subsequent Events | 12 Months Ended |
Dec. 31, 2023 | |
Subsequent Events [Abstract] | |
Subsequent Events | 10. Subsequent Events Sales of Common Stock through the Jefferies ATM Offering Program From January 1, 2024 through March 13, 2024, we sold an aggregate of 4,441,509 shares of common stock at a weighted-average price of $1.75 per share through the Jefferies ATM Offering Program for net proceeds of $7.6 million. |
Summary of Significant Accoun_2
Summary of Significant Accounting Policies (Policies) | 12 Months Ended |
Dec. 31, 2023 | |
Accounting Policies [Abstract] | |
Organization and Business | Organization and Business We were incorporated in the state of Delaware on September 8, 2005. We are a clinical stage biotechnology company leveraging evolutionary intelligence to translate tRNA synthetase biology into new therapies for fibrosis and inflammation. tRNA synthetases are ancient, essential proteins that have evolved novel domains that regulate diverse pathways extracellularly in humans. Our discovery platform is focused on unlocking hidden therapeutic intervention points by uncovering signaling pathways driven by our proprietary library of domains derived from all 20 tRNA synthetases. |
Principles of Consolidation | Principles of Consolidation Our consolidated financial statements include our accounts and our 98 % majority-owned subsidiary in Hong Kong, Pangu BioPharma Limited (Pangu BioPharma). All intercompany transactions and balances are eliminated in consolidation. |
Liquidity and Financial Condition | Liquidity and Financial Condition We have incurred losses and negative cash flows from operations since our inception. As of December 31, 2023, we had an accumulat ed deficit of $ 468.0 million and we expect to continue to incur net losses for the foreseeable future. As of December 31, 2023, our cash, cash equivalents, available-for-sale investments and restricted cash were $ 101.7 million. We currently have an “at-the-market” offering program (the Jefferies ATM Offering Program) through an Open Market Sale Agreement SM with Jefferies LLC (Jefferies). During the year ended December 31, 2023, we sold an aggregate of 10,530,795 shares of common stock at a weighted-average price of $ 1.82 per share for net proceeds of approximately $ 18.4 million under the Jefferies ATM Offering Program. Additionally, from January 1, 2024 through March 13, 2024, we sold an aggregate of 4,441,509 shares of common stock at a weighted-average price of $1.75 per share for net proceeds of approximately $7.6 million under the Jefferies ATM Offering Program. We believe that our current cash, cash equivalents, available-for-sale investments and restricted cash, will be sufficient to meet our anticipated cash requirements for a period of at least one year from the date of this Annual Report. We do not expect to generate any revenues from product sales unless and until we successfully complete development and obtain regulatory approval for one or more of our product candidates, which we expect will take a number of years at a minimum. If we obtain regulatory approval for any of our product candidates, we expect to incur significant commercialization expenses related to product sales, marketing, manufacturing and distribution. Accordingly, we will need to raise substantial additional capital to fund our operations. The amount and timing of our future funding requirements will depend on many factors, including the pace and results of our preclinical and clinical development efforts and the timing and nature of the regulatory approval process for our product candidates. We anticipate that we will seek to fund our operations through equity offerings, grant funding, collaborations, strategic partnerships and/or licensing arrangements, and when we are closer to commercialization of our product candidates potentially through debt financings. However, we may be unable to raise additional capital or enter into such arrangements when needed on favorable terms or at all. Our failure to raise capital or enter into such arrangements when needed would have a negative impact on our financial condition and ability to develop our product candidates. |
Restricted Cash | Restricted Cash As of December 31, 2023, restricted cash was approximately $ 3.5 million, which was held as a security deposit in conjunction with our corporate headquarter facility lease and financing leases as discussed further in Note 6 - Commitments and Contingencies. |
Use of Estimates | Use of Estimates Our consolidated financial statements are prepared in accordance with generally accepted accounting principles (GAAP). The preparation of our consolidated financial statements requires us to make estimates and assumptions that impact the reported amounts of assets, liabilities and expenses and the disclosure for these items in our consolidated financial statements and accompanying notes. The most significant estimates in our consolidated financial statements relate to the fair value of equity issuances and awards, and clinical trial and research and development expenses. Although these estimates are based on our knowledge of current events and actions we may undertake in the future, actual results may ultimately differ materially from these estimates and assumptions. |
Segment Reporting | Segment Reporting Operating segments are identified as components of an enterprise about which separate discrete financial information is available for evaluation by the chief operating decision-maker in making decisions regarding resource allocation and assessing performance. We view our operations and manage our business in one operating segment |
Cash and Cash Equivalents and Restricted Cash | Cash and Cash Equivalents and Restricted Cash Cash, cash equivalents and restricted cash consist of checking, money market and highly liquid investments that are readily convertible to cash and that have an original maturity of three months or less from date of purchase. The carrying amounts approximate fair value due to the short maturities of these instruments. |
Employee Retention Credit | Employee Retention Credit On March 27, 2020, the Coronavirus Aid, Relief, and Economic Security Act (CARES Act) was signed into law providing numerous tax incentives and other stimulus measures, including an employee retention credit (ERC), which is a refundable tax credit against certain employment taxes. The Taxpayer Certainty and Disaster Tax Relief Act of 2020 and the American Rescue Plan Act of 2021 extended and expanded the availability of the ERC. As a result of the foregoing legislation, we determined that we are eligible to claim an ERC benefit equal to 50 % of qualified wages that we paid to our employees between March 17, 2020 and December 31, 2020, and 70 % of the qualified wages that we paid to our employees between January 1, 2021 and September 30, 2021. Qualified wages are limited to $ 10,000 per employee for March 17, 2020 through December 31, 2020, and $ 10,000 per employee per calendar quarter from January 1, 2021 through September 30, 2021. Our credit was primarily derived from qualified wages during January 1, 2021 through September 30, 2021. To determine eligibility for January 1, 2021 through September 30, 2021, we compared gross receipts for each calendar quarter in 2021 to the corresponding calendar quarter in 2019 and determined that we had met the requirement for a decline in gross receipts. Accounting Standards Codification (ASC) Topic 105, Generally Accepted Accounting Principles describes the decision-making framework when no guidance exists in U.S. GAAP for a particular transaction. Specifically, ASC 105-10-05-2 instructs companies to look for guidance for a similar transaction within U.S. GAAP and apply that guidance by analogy. We accounted for the ERC by analogy to International Accounting Standards (IAS) 20, Accounting for Government Grants and Disclosure of Government Assistance, of International Financial Reporting Standards (IFRS). Under an IAS 20 analogy, a business entity would recognize the credit on a systematic basis over the periods in which the entity recognizes the payroll expenses for which the ERC is intended to compensate when there is reasonable assurance that the entity will comply with any conditions attached to the ERC and the ERC will be received. During the year ended December 31, 2023, we amended certain payroll tax filings and applied for a refund of $ 1.2 million of ERC benefits. The refund was recorded within the other receivables in our consolidated balance sheet, and as a $ 0.8 million reduction of research and development expenses and a $ 0.4 million reduction of general and administrative expenses in our consolidated statements of operations for the year ended December 31, 2023. |
Allowance of Credit Losses | Allowance of Credit Losses For available-for-sale securities in an unrealized loss position, we first assess whether we intend to sell, or if it is more likely than not that we will be required to sell, the security before recovery of its amortized cost basis. If either of the criteria regarding intent or requirement to sell is met, the security’s amortized cost basis is written down to fair value through earnings. For available-for-sale securities that do not meet the aforementioned criteria, we evaluate whether the decline in fair value has resulted from credit losses or other factors. In making this assessment, we consider the severity of the impairment, any changes in interest rates, market conditions, changes to the underlying credit ratings and forecasted recovery, among other factors. The credit-related portion of unrealized losses, and any subsequent improvements, are recorded in interest income through an allowance account. Any impairment that has not been recorded through an allowance for credit losses is included in other comprehensive income (loss) on the consolidated statements of operations and comprehensive loss. We elected the practical expedient to exclude the applicable accrued interest from both the fair value and amortized costs basis of our available-for-sale securities for purposes of identifying and measuring an impairment. Accrued interest receivable on available-for-sale securities is recorded within other receivables on our consolidated balance sheets. Our accounting policy is to not measure an allowance for credit loss for accrued interest receivable and to write-off any uncollectible accrued interest receivable as a reversal of interest income in a timely manner, which we consider to be in the period in which we determine the accrued interest will not be collected by us. |
Concentration of Credit Risk | Concentration of Credit Risk Financial instruments that potentially subject us to significant concentration of credit risk consist primarily of cash, cash equivalents, restricted cash and investment securities. We have established guidelines regarding diversification of investments and their maturities, which are designed to maintain principal and maximize liquidity. We maintain deposits in federally insured financial institutions in excess of federally insured limits. We have not experienced any losses in such accounts and we believe that we are not exposed to significant credit risk due to the financial position of the depository institutions in which those deposits are held. |
Property and Equipment | Property and Equipment Property and equipment are stated at cost and depreciated on a straight-line basis over the estimated useful life of the related assets (generally three to seven years ). Leasehold improvements are stated at cost and amortized on a straight-line basis over the lesser of the remaining term of the related lease or the estimated useful life of the leasehold improvements. Repairs and maintenance costs are charged to expense as incurred . |
Impairment of Long-Lived Assets | Impairment of Long-Lived Assets Long-lived assets consist primarily of property and equipment and right-of-use assets (ROU) associated with our operating and financing leases. An impairment loss is recorded if and when events and circumstances indicate that assets might be impaired and the undiscounted cash flows estimated to be generated by those assets are less than the carrying amount of those assets. While our current and historical operating losses are indicators of impairment, we believe that future cash flows to be received support the carrying value of our long-lived assets and, accordingly, have no t recognized any impairment losses since inception. |
Accrued Expenses | Accrued Expenses Accrued expenses include salaries, wages, benefits costs, consulting fees, legal and research and development costs. We have entered into contractual arrangements related to our clinical studies with clinical research organizations (CROs) and contracted development and manufacturing organizations (CDMOs) and recognize expense based on work completed and efforts expended pursuant to our contractual arrangements. We make estimates of our accrued CRO costs as of each balance sheet date based on facts and circumstances known at the time and include total trial management costs, sites activated, patients enrolled and number of patient visits. We estimate the time period over which services will be performed and the level of effort to be expended in each period. There may be instances in which payments made to our service providers including CROs and CDMOs, will temporarily exceed the level of services provided and result in a prepayment of the expense. If the actual timing of the performance of services or the level of effort varies from our estimate, we adjust the accrual or prepaid expense balance accordingly. Historically, our estimated accrued liabilities have materially approximated actual expenses incurred. |
Leases | Leases We determine if an arrangement is a lease at inception. Short-term leases with an initial term of 12 months or less are not recorded on our balance sheet. For long-term leases with an initial term of greater than 12 months, we recognize a right-of-use asset (ROU) and a lease liability based on the present value of future lease payments using an estimated rate of interest that we would pay to borrow equivalent funds on a collateralized basis at the lease commencement date. We determine the lease term at the commencement date by considering whether renewal options and termination options are reasonably assured of exercise. Rent expense for operating leases is recognized on a straight-line basis over the lease term and is included in operating expenses in our consolidated statements of operations. For financing leases, interest expense and amortization of the ROU is included in operating expenses in our consolidated statements of operations and variable lease payments are recorded as incurred. If a lease is modified, the modified contract is evaluated to determine whether it is or contains a lease. If a lease continues to exist, the lease modification is determined to be a separate contract when the modification grants the lessee an additional ROU that is not included in the original lease and the lease payments increase commensurate with the standalone price for the additional ROU. A lease modification that results in a separate contract will be accounted for in the same manner as a new lease. For a modification that is not a separate contract, we reassess the lease classification using the modified terms and conditions and the facts and circumstances as of the effective date of the modification and recognize the amount of the remeasurement of the lease liability for the modified lease as an adjustment to the corresponding lease ROU asset. Our ROU assets consist of non-cancelable operating leases and financing leases. Non-cancelable operating leases consist of leases for our corporate headquarters and additional laboratory space. Financing leases consist of leases for various research and development and information technology equipment. We do not separate lease and non-lease components for our long-term leases. |
Revenue Recognition | Revenue Recognition We evaluate our agreements under ASC Topic 606, Revenue from Contracts with Customers and ASC Topic 808, Collaborative Arrangements . We recognize revenue when we transfer promised goods or services to customers in an amount that reflects the consideration to which we expect to be entitled in exchange for those goods or services. In determining the appropriate amount of revenue to be recognized as we fulfill our obligations under our agreement, we perform the following steps: (i) identification of the promised goods or services in the contract; (ii) determination of whether the promised goods or services are performance obligations including whether they are distinct in the context of the contract; (iii) measurement of the transaction price, including the constraint on variable consideration; (iv) allocation of the transaction price to the performance obligations; and (v) recognition of revenue when (or as) we satisfy each performance obligation. As part of the accounting for these arrangements, we must develop assumptions that require judgment to determine the stand-alone selling price for each performance obligation identified in the contract. We use key assumptions to determine the stand-alone selling price, which may include forecasted revenues, development timelines, reimbursement rates for personnel costs, discount rates and probabilities of technical and regulatory success. We recognize revenue in one of two ways, over time or at a point in time. We recognize revenue over time when we are executing on our performance obligation over time and our partner receives benefit over time. For example, we recognize revenue over time when we provide research and development services. We recognize revenue at a point in time when we transfer control of a distinct performance obligation to our partner. For example, if a license to our intellectual property is determined to be distinct from the other performance obligations identified in the arrangement, we recognize revenues from non-refundable, up-front fees allocated to the license when the license is transferred to the licensee and the licensee is able to use and benefit from the license. |
Research and Development Costs | Research and Development Costs Research and development costs are expensed as incurred. Research and development costs include: salaries and employee-related expenses, including stock-based compensation and benefits for personnel in research and product development functions; costs associated with conducting our preclinical, development and regulatory activities, including fees paid to third-party professional consultants, service providers and our scientific, therapeutic and clinical advisors; costs to acquire, develop and manufacture preclinical study and clinical trial materials; costs incurred under clinical trial agreements with CROs and investigative sites; costs for laboratory supplies; payments related to licensed products and technologies; allocated facilities and information technology costs; and depreciation. |
Patent Costs | Patent Costs Costs related to filing and pursuing patent applications are recorded as general and administrative expense and expensed as incurred since recoverability of such expenditures is uncertain. |
Stock-Based Compensation | Stock-Based Compensation We evaluate our stock-based compensation arrangements under ASC Topic 718, Compensation – Stock Compensation. Stock-based compensation expense represents the grant date fair value of employee stock option and restricted stock unit grants recognized as expense over the requisite service period of the awards (usually the vesting period) on a straight-line basis. We estimate fair value of stock option grants using the Black-Scholes option pricing model. We estimate the fair value using assumptions, including the risk-free interest rate, the expected volatility of a peer group of similar companies, the expected term of the awards and the expected dividend yield. These estimates involve inherent uncertainties and the application of management’s judgment. If factors change and different assumptions are used, our stock-based compensation expense could be materially different in the future. |
Income Taxes | Income Taxes We account for income taxes under the asset and liability method, which requires the recognition of deferred tax assets and liabilities for the expected future tax consequences of events that have been included in the consolidated financial statements. Under this method, deferred tax assets and liabilities are determined on the basis of the differences between the consolidated financial statements and tax basis of assets and liabilities using enacted tax rates in effect for the year in which the differences are expected to reverse. The effect of a change in tax rates on deferred tax assets and liabilities is recognized as income in the period that includes the enactment date. We recognize net deferred tax assets to the extent that we believe these assets are more likely than not to be realized. In making such a determination, we consider all available positive and negative evidence, including future reversals of existing taxable temporary differences, projected future taxable income, tax-planning strategies and results of recent operations. If we determine that we would be able to realize the deferred tax assets in the future in excess of their net recorded amount, we would make an adjustment to the deferred tax asset valuation allowance, which would reduce the provision for income taxes. We record uncertain tax positions on the basis of a two-step process whereby (1) we determine whether it is more likely than not that the tax positions will be sustained on the basis of the technical merits of the position and (2) for those tax positions that meet the more-likely-than-not recognition threshold, we recognize the largest amount of tax benefit that is more than 50 % likely to be realized upon ultimate settlement with the related tax authority. We recognize interest and penalties related to unrecognized tax benefits within income tax expense. Any accrued interest and penalties are included within the related tax liability. |
Net Loss Per Share | Net Loss Per Share Basic net loss per share is calculated by dividing the net loss attributable to common stockholders by the weighted average number of common shares outstanding for the period, without consideration for common stock equivalents. Diluted net loss per share attributable to common stockholders is calculated by dividing the net loss attributable to common stockholders by the weighted average number of common stock and common stock equivalents outstanding for the period determined using the treasury-stock method. Dilutive common stock equivalents are comprised of convertible preferred stock, warrants for common stock, options and restricted stock units outstanding under our stock option plans and inducement grants and estimated shares to be purchased under our 2015 Employee Stock Purchase Plan (the 2015 ESPP). For all periods presented, there is no difference in the number of shares used to calculate basic and diluted shares outstanding due to our net loss position. Potentially dilutive securities not included in the calculation of diluted net loss per share because to do so would be anti-dilutive are as follows (in common share equivalents): Years Ended December 31, 2023 2022 2021 Common stock warrants 5,864 13,760 13,760 Common stock options and restricted stock units 4,020,154 3,077,608 1,420,050 Employee stock purchase plan 41,862 34,588 2,045 Total 4,067,880 3,125,956 1,435,855 The following table summarizes our net loss per share (in thousands, except per share data): Years Ended December 31, 2023 2022 2021 Numerator: Net loss attributable to aTyr Pharma, Inc. $ ( 50,389 ) $ ( 45,338 ) $ ( 33,768 ) Denominator: Shares used in computing net loss per share, basic and diluted 53,606,488 28,419,569 19,080,878 Net loss per share - basic and diluted $ ( 0.94 ) $ ( 1.60 ) $ ( 1.77 ) |
Recent Accounting Pronouncements | Recent Accounting Pronouncements In June 2016, the Financial Accounting Standards Board issued Accounting Standards Update (ASU) No. 2016-13, Financial Instruments – Credit Losses (Topic 326), to provide financial statement users with more decision-useful information about the expected credit losses on financial instruments and other commitments to extend credit held by a reporting entity at each reporting date. To achieve this objective, the amendments in Topic 326 replace the incurred loss impairment methodology in current U.S. GAAP with a methodology that reflects expected credit losses and requires consideration of a broader range of reasonable and supportable information to inform credit loss estimates. Topic 326 is effective for fiscal years beginning after December 15, 2022, including interim periods within those fiscal years for smaller reporting companies. We adopted Topic 326 on January 1, 2023 . The adoption did not have a material impact on our consolidated financial statements. In December 2023, the FASB, issued ASU 2023-09, Improvements to Income Tax Disclosures, which requires 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 fiscal years beginning after December 15, 2024, with early adoption permitted. We are currently evaluating the disclosure requirements related to the new standard. |
Summary of Significant Accoun_3
Summary of Significant Accounting Policies (Tables) | 12 Months Ended |
Dec. 31, 2023 | |
Accounting Policies [Abstract] | |
Schedule of Potentially Dilutive Securities Not Included in Calculation of Diluted Net Loss Per Share | Potentially dilutive securities not included in the calculation of diluted net loss per share because to do so would be anti-dilutive are as follows (in common share equivalents): Years Ended December 31, 2023 2022 2021 Common stock warrants 5,864 13,760 13,760 Common stock options and restricted stock units 4,020,154 3,077,608 1,420,050 Employee stock purchase plan 41,862 34,588 2,045 Total 4,067,880 3,125,956 1,435,855 |
Summary of Net Loss Per Share | The following table summarizes our net loss per share (in thousands, except per share data): Years Ended December 31, 2023 2022 2021 Numerator: Net loss attributable to aTyr Pharma, Inc. $ ( 50,389 ) $ ( 45,338 ) $ ( 33,768 ) Denominator: Shares used in computing net loss per share, basic and diluted 53,606,488 28,419,569 19,080,878 Net loss per share - basic and diluted $ ( 0.94 ) $ ( 1.60 ) $ ( 1.77 ) |
Fair Value Measurements (Tables
Fair Value Measurements (Tables) | 12 Months Ended |
Dec. 31, 2023 | |
Fair Value Disclosures [Abstract] | |
Schedule of Assets Measured at Fair Value on Recurring Basis | Assets measured at fair value on a recurring basis are as follows (in thousands): Fair Value Measurements Using Total Quoted Prices in Markets Identical Significant Significant As of December 31, 2023 Assets: Current: Cash equivalents $ 21,626 $ 21,626 $ — $ — Available-for-sale investments: Commercial paper 31,198 — 31,198 — Corporate debt securities 27,578 — 27,578 — U.S. government agencies 16,846 — 16,846 — Total available-for-sale investments 75,622 — 75,622 — Total assets measured at fair value $ 97,248 $ 21,626 $ 75,622 $ — Fair Value Measurements Using Total Quoted Prices in Markets Identical Significant Significant As of December 31, 2022 Assets: Current: Cash equivalents $ 8,585 $ 8,585 $ — $ — Available-for-sale investments: Commercial paper 28,074 — 28,074 — Corporate debt securities 26,094 — 26,094 — Municipal bonds 1,997 — 1,997 — Total available-for-sale investments 56,165 — 56,165 — Total assets measured at fair value $ 64,750 $ 8,585 $ 56,165 $ — |
Schedule of Available-for-sale Investments | As of December 31, 2023 and 2022, available-for-sale investments are detailed as follows (in thousands): December 31, 2023 Contractual Maturity Gross Gross Gross Market Value Available-for-sale investments: Commercial paper Within 1 year $ 31,198 $ 14 $ ( 14 ) $ 31,198 Corporate debt securities Within 2 years 27,607 12 ( 41 ) 27,578 U.S. government agencies Within 1 year 16,841 26 ( 21 ) 16,846 $ 75,646 $ 52 $ ( 76 ) $ 75,622 December 31, 2022 Contractual Maturity Gross Gross Gross Market Value Available-for-sale investments: Commercial paper Within 1 year $ 28,121 $ — $ ( 47 ) $ 28,074 Corporate debt securities Within 2 years 26,401 — ( 307 ) 26,094 Municipal bonds Within 1 year 2,026 — ( 29 ) 1,997 $ 56,548 $ — $ ( 383 ) $ 56,165 |
Balance Sheet Details (Tables)
Balance Sheet Details (Tables) | 12 Months Ended |
Dec. 31, 2023 | |
Balance Sheet Details [Abstract] | |
Schedule of Prepaid Expenses | Prepaid expenses consist of the following (in thousands): December 31, 2023 2022 Prepaid clinical and research expense $ 1,475 $ 334 Prepaid manufacturing expenses 125 2,049 Other prepaid expenses 790 567 $ 2,390 $ 2,950 |
Summary of Property and Equipment | Property and equipment consist of the following (in thousands): December 31, 2023 2022 Computer and office equipment $ 448 $ 620 Scientific and laboratory equipment 4,051 4,379 Tenant improvements 5,653 4,414 10,152 9,413 Less accumulated depreciation and amortization ( 4,621 ) ( 6,354 ) $ 5,531 $ 3,059 |
Summary of Accrued Expenses | Accrued expenses consist of the following (in thousands): December 31, 2023 2022 Accrued salaries, wages and benefits $ 2,706 $ 2,781 Accrued clinical and manufacturing 7,753 5,151 Other accrued expenses 1,100 1,930 $ 11,559 $ 9,862 |
Commitments and Contingencies (
Commitments and Contingencies (Tables) | 12 Months Ended |
Dec. 31, 2023 | |
Debt Instruments [Abstract] | |
Schedule of Future Minimum Payments under Non-cancelable Operating Lease and Reconciliation to Operating Lease Liability | Future minimum payments under the facility lease and reconciliation to the operating lease liability as of December 31, 2023 were as follows (in thousands): Operating Leases 2024 $ 1,949 2025 1,975 2026 1,923 2027 1,942 2028 and thereafter 11,968 Less: Amount representing interest ( 6,289 ) Present value of lease payments 13,468 Less: Current portion of operating lease liability ( 831 ) Less: Tenant improvement allowance not yet received ( 298 ) Long-term operating lease liability, net of current portion $ 12,339 |
Schedule of Future Minimum Payments under Non-cancelable Financing Lease and Reconciliation to Financing Lease Liability | Future minimum payments under the financing lease and reconciliation to the financing lease liability as of December 31, 2023 were as follows (in thousands): Financing Leases 2024 $ 634 2025 634 2026 676 2027 264 Less: Amount representing interest ( 283 ) Present value of lease payments 1,925 Less: Current portion of financing lease liability ( 497 ) Long-term financing lease liability, net of current portion $ 1,428 |
Stockholders' Equity (Tables)
Stockholders' Equity (Tables) | 12 Months Ended |
Dec. 31, 2023 | |
Summary of Stock Option Activity | Stock option activity is summarized as follows: Number of Weighted- Weighted Aggregate Outstanding as of December 31, 2022 2,956,170 $ 7.45 Granted 1,112,885 $ 2.21 Canceled/forfeited/expired ( 112,228 ) $ 6.42 Outstanding as of December 31, 2023 3,956,827 $ 6.00 7.94 $ — |
Summary of Assumptions Used to Determine Fair Value of Employee Stock Purchase Plan | The assumptions used in the Black-Scholes option pricing model to determine the fair value of the ESPP offering were as follows: Years Ended December 31, 2023 2022 2021 Expected term (in years) 0.50 0.50 0.50 Risk-free interest rate 4.54 % – 5.38 % 0.06 % – 4.54 % 0.04 % – 0.12 % Expected volatility 40.9 % – 58.5 % 51.9 % – 95.9 % 89.7 % – 108.12 % Expected dividend yield 0.0 % 0.0 % 0.0 % |
Schedule of Restricted Stock Units Activity | Occasionally, we grant restricted stock units to employees. The fair value of restricted stock is determined by the closing price of our common stock reported on the Nasdaq Capital Market on the date of grant. Restricted stock unit activity is summarized as follows: Number of Outstanding Weighted-Average Balance as of December 31, 2022 121,438 $ 5.09 Released ( 58,111 ) $ 4.69 Balance as of December 31, 2023 63,327 $ 5.45 |
Schedule of Allocation of Stock-Based Compensation for All Options Including Performance Options with Market Condition and Restricted Stock Units | The allocation of stock-based compensation for all options, including performance options with market condition and restricted stock units is as follows (in thousands): Years Ended December 31, 2023 2022 2021 Research and development $ 600 $ 528 $ 295 General and administrative 2,000 1,626 1,319 Total stock-based compensation expense $ 2,600 $ 2,154 $ 1,614 |
Summary of Warrants Outstanding | Warrants Warrants outstanding for the purchase of common stock as of December 31, 2023 were as follows: Number Exercise Price Expiration Outstanding Per Share Date 2,978 $ 50.37 June 2024 2,886 $ 51.98 December 2024 5,864 |
Summary of Common Stock Reserved for Future Issuance | Common Stock Reserved for Future Issuance Common stock reserved for future issuance was as follows: December 31, 2023 Common stock warrants 5,864 Common stock options and restricted stock units 4,020,154 Shares available under the 2015 equity incentive plan 3,964,555 Shares available under the 2022 inducement plan 95,367 Shares available under the employee stock purchase plan 727,311 8,813,251 |
Employee Stock Option [Member] | |
Summary of Assumptions Used to Determine Fair Value of Employee Stock Option Grants and Performance Options with Market Condition | The assumptions used in the Black-Scholes option pricing model to determine the fair value of the employee stock option grants were as follows: Years Ended December 31, 2023 2022 2021 Expected term (in years) 5.51 – 6.09 5.98 – 6.08 5.50 – 6.08 Risk-free interest rate 3.58 % – 4.5 % 1.7 % – 4.2 % 0.6 % – 1.3 % Expected volatility 81.5 % – 83.0 % 84.2 % – 86.5 % 86.3 % – 104.8 % Expected dividend yield 0.0 % 0.0 % 0.0 % |
Income Tax (Tables)
Income Tax (Tables) | 12 Months Ended |
Dec. 31, 2023 | |
Income Tax Disclosure [Abstract] | |
Schedule of Pretax Losses for Domestic and Foreign Operations | Pretax losses were generated by both domestic and foreign operations as follows (in thousands): Years Ended December 31, 2023 2022 2021 United States $ ( 49,967 ) $ ( 45,086 ) $ ( 33,316 ) Foreign ( 428 ) ( 254 ) ( 458 ) Worldwide pre-tax loss $ ( 50,395 ) $ ( 45,340 ) $ ( 33,774 ) |
Schedule of Reconciliations of the Expected Statutory Federal Income Tax | A reconciliation of the expected statutory federal income tax provision to the actual income tax provision is summarized as follows (in thousands): Years Ended December 31, 2023 2022 2021 Expected income taxes benefit at federal statutory rate $ ( 10,583 ) $ ( 9,521 ) $ ( 7,093 ) State income taxes, net of federal benefit ( 2,171 ) ( 380 ) ( 2,313 ) Permanent items and other 172 438 592 Stock compensation 91 44 90 Research credits ( 5,336 ) ( 4,415 ) ( 1,253 ) Unrecognized tax benefits 5,209 2,454 500 Foreign rate differential 19 11 21 Change in tax rate ( 5 ) 34 52 Change in valuation allowance 12,604 11,335 9,404 Income tax (benefit) expense $ — $ — $ — |
Schedule of Significant Components of Deferred Tax Assets | Significant components of our deferred tax assets are summarized as follows (in thousands): December 31, 2023 2022 Deferred tax assets: Net operating loss carryforwards $ 60,090 $ 52,752 Capitalized research and development expenses 25,922 22,576 Research credits and other state credits 18,246 16,021 Intangible assets 1,093 1,278 Reserve and accruals 522 596 Share-based compensation expense 1,821 1,628 Lease liability 1,709 2,157 Total tax assets 109,403 97,008 Valuation allowance ( 107,989 ) ( 95,484 ) Total deferred tax assets $ 1,414 $ 1,524 Deferred tax liabilities: Right of use lease assets ( 1,414 ) ( 1,524 ) Total deferred tax liabilities ( 1,414 ) ( 1,524 ) Net deferred tax assets $ — $ — |
Schedule of Activity Related to Unrecognized Tax Benefits | The activity related to our unrecognized tax benefits is summarized as follows (in thousands): December 31, 2023 2022 2021 Balance as of beginning of year $ 25,145 $ 22,232 $ 21,707 Increase (decrease) related to prior year tax positions ( 483 ) ( 48 ) ( 9 ) Increase related to current year tax positions 5,416 2,961 534 Balance as of end of year $ 30,078 $ 25,145 $ 22,232 |
Organization, Business and Ba_2
Organization, Business and Basis of Presentation - Additional Information (Detail) $ / shares in Units, $ in Thousands | 1 Months Ended | 12 Months Ended | |||
Feb. 28, 2023 USD ($) $ / shares shares | Sep. 30, 2021 USD ($) $ / shares shares | Dec. 31, 2023 USD ($) Segment $ / shares shares | Dec. 31, 2022 USD ($) $ / shares shares | Dec. 31, 2021 USD ($) | |
Description Of Business [Line Items] | |||||
Accumulated deficit | $ (468,023) | $ (417,634) | |||
Cash equivalents, available-for-sale investments and restricted cash | 101,700 | ||||
Restricted cash | $ 3,484 | $ 3,165 | $ 0 | ||
Number of operating segment | Segment | 1 | ||||
Public Offerings [Member] | |||||
Description Of Business [Line Items] | |||||
Proceeds from Issuance of Common Stock | $ 48,100 | $ 80,600 | |||
Public Offerings [Member] | Common Stock [Member] | |||||
Description Of Business [Line Items] | |||||
Number of shares issued and sold | shares | 23,125,000 | 10,781,250 | |||
Shares Issued, Price Per Share | $ / shares | $ 2.25 | $ 8 | |||
ATM Offering Program [Member] | Jefferies LLC [Member] | |||||
Description Of Business [Line Items] | |||||
Shares Issued, Price Per Share | $ / shares | $ 1.82 | $ 3.09 | |||
Proceeds from Issuance of Common Stock | $ 18,400 | $ 4,000 | |||
ATM Offering Program [Member] | Common Stock [Member] | Jefferies LLC [Member] | |||||
Description Of Business [Line Items] | |||||
Number of shares issued and sold | shares | 10,530,795 | 1,421,627 | |||
Pangu BioPharma [Member] | Hong Kong [Member] | |||||
Description Of Business [Line Items] | |||||
Majority-owned subsidiary percentage | 98% |
Summary of Significant Accoun_4
Summary of Significant Accounting Policies - Additional Information (Detail) - USD ($) | 9 Months Ended | 12 Months Ended | |
Sep. 30, 2021 | Dec. 31, 2020 | Dec. 31, 2023 | |
Significant Accounting Policies [Line Items] | |||
Employee retention of payroll expenses | $ 1,200,000 | ||
Impairment of long lived assets | $ 0 | ||
Accounting Standards Update 2016-13 [Member] | |||
Significant Accounting Policies [Line Items] | |||
Change in accounting principle, accounting standards update, adopted | true | ||
Change in accounting principle, accounting standards update, adoption date | Jan. 01, 2023 | ||
Change in accounting principle, accounting standards update, immaterial effect | true | ||
General and Administrative Expense [Member] | |||
Significant Accounting Policies [Line Items] | |||
Employee retention credit receivable - general and administrative expenses | $ 400,000 | ||
Research and Development Expense [Member] | |||
Significant Accounting Policies [Line Items] | |||
Employee retention credit receivable - research and development expenses | $ 800,000 | ||
Cares Act [Member] | |||
Significant Accounting Policies [Line Items] | |||
Percentage of employee retention credit benefit can be claimed on qualified wages | 70% | 50% | |
Threshold qualified wages per employee per calendar quarter | $ 10,000,000 | $ 10,000,000 | |
Maximum [Member] | |||
Significant Accounting Policies [Line Items] | |||
Estimated useful life of property and equipment | 7 years | ||
Minimum [Member] | |||
Significant Accounting Policies [Line Items] | |||
Estimated useful life of property and equipment | 3 years | ||
Percentage of tax benefit to be realized upon settlement | 50% |
Summary of Significant Accoun_5
Summary of Significant Accounting Policies - Schedule of Potentially Dilutive Securities Not Included in Calculation of Diluted Net Loss Per Share (Detail) - shares | 12 Months Ended | ||
Dec. 31, 2023 | Dec. 31, 2022 | Dec. 31, 2021 | |
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] | |||
Anti-dilutive securities not included in calculation of diluted net loss per share | 4,067,880 | 3,125,956 | 1,435,855 |
Common Stock Warrants [Member] | |||
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] | |||
Anti-dilutive securities not included in calculation of diluted net loss per share | 5,864 | 13,760 | 13,760 |
Common Stock Options and Restricted Stock Units [Member] | |||
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] | |||
Anti-dilutive securities not included in calculation of diluted net loss per share | 4,020,154 | 3,077,608 | 1,420,050 |
Employee Stock Purchase Plan [Member] | |||
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] | |||
Anti-dilutive securities not included in calculation of diluted net loss per share | 41,862 | 34,588 | 2,045 |
Summary of Significant Accoun_6
Summary of Significant Accounting Policies - Summary of Net Loss Per Share (Detail) - USD ($) $ / shares in Units, $ in Thousands | 12 Months Ended | ||
Dec. 31, 2023 | Dec. 31, 2022 | Dec. 31, 2021 | |
Numerator: | |||
Net loss attributable to aTyr Pharma, Inc. | $ (50,389) | $ (45,338) | $ (33,768) |
Denominator: | |||
Shares used in computing net loss per share, basic | 53,606,488 | 28,419,569 | 19,080,878 |
Shares used in computing net loss per share, diluted | 53,606,488 | 28,419,569 | 19,080,878 |
Net loss per share - basic | $ (0.94) | $ (1.6) | $ (1.77) |
Net loss per share - diluted | $ (0.94) | $ (1.6) | $ (1.77) |
Fair Value Measurements - Sched
Fair Value Measurements - Schedule of Assets Measured at Fair Value on Recurring Basis (Detail) - Fair Value, Measurements, Recurring [Member] - USD ($) $ in Thousands | Dec. 31, 2023 | Dec. 31, 2022 |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ||
Cash equivalents | $ 21,626 | $ 8,585 |
Total assets measured at fair value | 97,248 | 64,750 |
Available-for-sale [Member] | ||
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ||
Investments, fair value | 75,622 | 56,165 |
Available-for-sale [Member] | Commercial Paper [Member] | ||
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ||
Investments, fair value | $ 31,198 | $ 28,074 |
Investment, Type [Extensible Enumeration] | Short-Term Investments [Member] | Short-Term Investments [Member] |
Available-for-sale [Member] | Corporate Debt Securities [Member] | ||
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ||
Investments, fair value | $ 27,578 | $ 26,094 |
Investment, Type [Extensible Enumeration] | Short-Term Investments [Member] | Short-Term Investments [Member] |
Available-for-sale [Member] | Municipal Bonds [Member] | ||
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ||
Investments, fair value | $ 1,997 | |
Investment, Type [Extensible Enumeration] | Short-Term Investments [Member] | |
Available-for-sale [Member] | U.S. Government Agencies [Member] | ||
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ||
Investments, fair value | $ 16,846 | |
Investment, Type [Extensible Enumeration] | Short-Term Investments [Member] | |
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | ||
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ||
Cash equivalents | $ 21,626 | $ 8,585 |
Total assets measured at fair value | 21,626 | 8,585 |
Significant Other Observable Inputs (Level 2) [Member] | ||
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ||
Total assets measured at fair value | 75,622 | 56,165 |
Significant Other Observable Inputs (Level 2) [Member] | Available-for-sale [Member] | ||
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ||
Investments, fair value | 75,622 | 56,165 |
Significant Other Observable Inputs (Level 2) [Member] | Available-for-sale [Member] | Commercial Paper [Member] | ||
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ||
Investments, fair value | $ 31,198 | $ 28,074 |
Investment, Type [Extensible Enumeration] | Short-Term Investments [Member] | Short-Term Investments [Member] |
Significant Other Observable Inputs (Level 2) [Member] | Available-for-sale [Member] | Corporate Debt Securities [Member] | ||
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ||
Investments, fair value | $ 27,578 | $ 26,094 |
Investment, Type [Extensible Enumeration] | Short-Term Investments [Member] | Short-Term Investments [Member] |
Significant Other Observable Inputs (Level 2) [Member] | Available-for-sale [Member] | Municipal Bonds [Member] | ||
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ||
Investments, fair value | $ 1,997 | |
Investment, Type [Extensible Enumeration] | Short-Term Investments [Member] | |
Significant Other Observable Inputs (Level 2) [Member] | Available-for-sale [Member] | U.S. Government Agencies [Member] | ||
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ||
Investments, fair value | $ 16,846 | |
Investment, Type [Extensible Enumeration] | Short-Term Investments [Member] |
Fair Value Measurements - Sch_2
Fair Value Measurements - Schedule of Available-for-sale Investments (Detail) - USD ($) $ in Thousands | Dec. 31, 2023 | Dec. 31, 2022 |
Schedule of Available-for-sale Securities [Line Items] | ||
Gross Amortized Cost | $ 75,646 | $ 56,548 |
Gross Unrealized Gains | 52 | |
Gross Unrealized Losses | (76) | (383) |
Market Value | 75,622 | 56,165 |
Commercial Paper [Member] | ||
Schedule of Available-for-sale Securities [Line Items] | ||
Gross Amortized Cost | 31,198 | 28,121 |
Gross Unrealized Gains | 14 | |
Gross Unrealized Losses | (14) | (47) |
Market Value | 31,198 | 28,074 |
Municipal Bonds [Member] | ||
Schedule of Available-for-sale Securities [Line Items] | ||
Gross Amortized Cost | 2,026 | |
Gross Unrealized Losses | (29) | |
Market Value | 1,997 | |
Corporate Debt Securities [Member] | ||
Schedule of Available-for-sale Securities [Line Items] | ||
Gross Amortized Cost | 27,607 | 26,401 |
Gross Unrealized Gains | 12 | |
Gross Unrealized Losses | (41) | (307) |
Market Value | 27,578 | $ 26,094 |
U.S. Government Agencies [Member] | ||
Schedule of Available-for-sale Securities [Line Items] | ||
Gross Amortized Cost | 16,841 | |
Gross Unrealized Gains | 26 | |
Gross Unrealized Losses | (21) | |
Market Value | $ 16,846 |
Fair Value Measurements - Addit
Fair Value Measurements - Additional Information (Detail) $ in Millions | 12 Months Ended | |
Dec. 31, 2023 USD ($) Position | Dec. 31, 2022 USD ($) | |
Schedule of Available-for-sale Securities [Line Items] | ||
Available-for-sale, investments in unrealized loss positions, number of positions | Position | 19 | |
Available for sale investments number of positions | Position | 25 | |
Available-for-sale, investments in unrealized loss positions, greater than 12 months | Position | 1 | |
Available-for-sale, investments in unrealized loss positions, greater than twelve months, market value | $ 2 | |
Accrued interest receivable on available-for-sale | $ 0.3 | $ 0.2 |
Maximum [Member] | ||
Schedule of Available-for-sale Securities [Line Items] | ||
Available-for-sale investments effective maturity period | 2 years | |
Short-term investments | $ 1 | |
Minimum [Member] | ||
Schedule of Available-for-sale Securities [Line Items] | ||
Short-term investments | $ 74.6 | |
Available-for-sale investments gross unrealized loss positions, period | 12 months |
License, Collaboration and Ot_2
License, Collaboration and Other Agreements - Additional Information (Detail) - USD ($) $ in Thousands | 1 Months Ended | 12 Months Ended | ||
Feb. 28, 2023 | Dec. 31, 2023 | Dec. 31, 2022 | Dec. 31, 2021 | |
Research And Development Arrangement Contract To Perform For Others [Line Items] | ||||
Revenue | $ 353 | $ 10,386 | $ 0 | |
Collaboration Revenue [Member] | ||||
Research And Development Arrangement Contract To Perform For Others [Line Items] | ||||
Revenue | $ 10,000 | |||
Additional Collaboration Revenue [Member] | ||||
Research And Development Arrangement Contract To Perform For Others [Line Items] | ||||
Revenue | 400 | |||
Kyorin Pharmaceutical Co Ltd [Member] | ||||
Research And Development Arrangement Contract To Perform For Others [Line Items] | ||||
Upfront and milestone payments received | 20,000 | |||
Milestone payments received | $ 10,000 | |||
Development Regulatory And Sales Milestones [Member] | Kyorin Pharmaceutical Co Ltd [Member] | ||||
Research And Development Arrangement Contract To Perform For Others [Line Items] | ||||
Remaining receivable based on achievement of research milestones | $ 155,000 |
Balance Sheet Details - Summary
Balance Sheet Details - Summary of Prepaid Expenses (Detail) - USD ($) $ in Thousands | Dec. 31, 2023 | Dec. 31, 2022 |
Prepaid Expenses [Line Items] | ||
Prepaid expenses | $ 2,390 | $ 2,950 |
Prepaid Clinical and Research Expense [Member] | ||
Prepaid Expenses [Line Items] | ||
Prepaid expenses | 1,475 | 334 |
Prepaid Manufacturing Expenses [Member] | ||
Prepaid Expenses [Line Items] | ||
Prepaid expenses | 125 | 2,049 |
Other Prepaid Expenses [Member] | ||
Prepaid Expenses [Line Items] | ||
Prepaid expenses | $ 790 | $ 567 |
Balance Sheet Details - Summa_2
Balance Sheet Details - Summary of Property and Equipment (Detail) - USD ($) $ in Thousands | Dec. 31, 2023 | Dec. 31, 2022 |
Property Plant And Equipment [Line Items] | ||
Property and equipment, Gross | $ 10,152 | $ 9,413 |
Less accumulated depreciation and amortization | (4,621) | (6,354) |
Property and equipment, Net | 5,531 | 3,059 |
Computer and Office Equipment [Member] | ||
Property Plant And Equipment [Line Items] | ||
Property and equipment, Gross | 448 | 620 |
Scientific and Laboratory Equipment [Member] | ||
Property Plant And Equipment [Line Items] | ||
Property and equipment, Gross | 4,051 | 4,379 |
Tenant Improvements [Member] | ||
Property Plant And Equipment [Line Items] | ||
Property and equipment, Gross | $ 5,653 | $ 4,414 |
Balance Sheet Details - Additio
Balance Sheet Details - Additional Information (Detail) - USD ($) $ in Thousands | 12 Months Ended | ||
Dec. 31, 2023 | Dec. 31, 2022 | Dec. 31, 2021 | |
Property, Plant and Equipment [Abstract] | |||
Depreciation expense | $ 592 | $ 232 | $ 475 |
Balance Sheet Details - Summa_3
Balance Sheet Details - Summary of Accrued Expenses (Detail) - USD ($) $ in Thousands | Dec. 31, 2023 | Dec. 31, 2022 |
Accrued Liabilities, Current [Abstract] | ||
Accrued salaries, wages and benefits | $ 2,706 | $ 2,781 |
Accrued clinical and manufacturing | 7,753 | 5,151 |
Other accrued expenses | 1,100 | 1,930 |
Accrued expenses | $ 11,559 | $ 9,862 |
Commitments and Contingencies -
Commitments and Contingencies - Additional Information (Detail) | 1 Months Ended | 12 Months Ended | |||||
Feb. 29, 2024 USD ($) | May 31, 2022 USD ($) ft² | Dec. 31, 2023 USD ($) | Dec. 31, 2022 USD ($) | Dec. 31, 2021 USD ($) | Jun. 30, 2023 ft² | Mar. 20, 2023 | |
Commitments and Contingencies [Line Items] | |||||||
Lease space | ft² | 23,696 | 1,500 | |||||
Operating lease, term of lease | 124 months | ||||||
Lessee operating lease, lease commencement date | Mar. 20, 2023 | ||||||
Operating lease, lease not yet commenced, option to extend | We also have one option to extend the Lease Term for five years. | ||||||
Operating lease, lease not yet commenced, existence of option to extend | true | ||||||
Operating lease, lease not yet commenced, extension term | 5 years | ||||||
Base rent per square foot | $ 5.75 | ||||||
Annual upward adjustments on base rate, percentage | 3% | ||||||
Proceeds from the landlord | $ 5,000,000 | ||||||
Security deposit | 700,000 | ||||||
Operating lease expense | $ 1,900,000 | $ 1,500,000 | $ 1,000,000 | ||||
Operating lease, weighted average remaining lease term | 9 years 4 months 24 days | 9 years 10 months 24 days | |||||
Operating lease, weighted average discount rate | 8.80% | 8.80% | |||||
Financing lease, term of contract | 48 months | ||||||
Financing lease, weighted-average remaining lease term | 3 years | 3 years 8 months 12 days | |||||
Financing lease, weighted-average discount rate | 8.30% | 7.90% | |||||
Subsequent Events [Member] | |||||||
Commitments and Contingencies [Line Items] | |||||||
Proceeds from the landlord | $ 300,000 | ||||||
Leased Equipment [Member] | Restricted Cash [Member] | |||||||
Commitments and Contingencies [Line Items] | |||||||
Security deposit | $ 2,700,000 | ||||||
Maximum [Member] | |||||||
Commitments and Contingencies [Line Items] | |||||||
Allowance for tenant improvements | $ 5,300,000 |
Commitments and Contingencies_2
Commitments and Contingencies - Schedule of Future Minimum Payments under Facility Lease and Reconciliation to Operating Lease Liability (Detail) - USD ($) $ in Thousands | Dec. 31, 2023 | Dec. 31, 2022 |
Leases, Operating [Abstract] | ||
2024 | $ 1,949 | |
2025 | 1,975 | |
2026 | 1,923 | |
2027 | 1,942 | |
2028 and thereafter | 11,968 | |
Less: Amount representing interest | (6,289) | |
Present value of lease payments | 13,468 | |
Less: Current portion of operating lease liability | (831) | $ (630) |
Less: Tenant improvement allowance not yet received | (298) | |
Long-term operating lease liability, net of current portion | $ 12,339 | $ 9,633 |
Commitments and Contingencies_3
Commitments and Contingencies - Schedule of Future Minimum Payments under Financing Lease and Reconciliation to Financing Lease Liability (Detail) - USD ($) $ in Thousands | Dec. 31, 2023 | Dec. 31, 2022 |
Finance Lease, Liability [Abstract] | ||
2024 | $ 634 | |
2025 | 634 | |
2026 | 676 | |
2027 | 264 | |
Less: Amount representing interest | (283) | |
Present value of lease payments | 1,925 | |
Less: Current portion of financing lease liability | (497) | $ (264) |
Long-term financing lease liability, net of current portion | $ 1,428 | $ 1,007 |
Stockholders' Equity - Addition
Stockholders' Equity - Additional Information (Detail) - USD ($) | 1 Months Ended | 3 Months Ended | 12 Months Ended | |||||||||
Feb. 28, 2023 | Mar. 31, 2022 | Sep. 30, 2021 | Sep. 30, 2020 | Mar. 31, 2022 | Dec. 31, 2023 | Dec. 31, 2022 | Dec. 31, 2021 | Apr. 30, 2022 | Mar. 31, 2021 | Nov. 30, 2020 | May 31, 2019 | |
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] | ||||||||||||
Commission Rate Equal To Gross Proceeds1 | 3% | 3% | ||||||||||
Number of common stock shares reserved for issuance | 8,813,251 | |||||||||||
Stock options granted | 1,112,885 | |||||||||||
Weighted average grant date fair value of options granted | $ 1.59 | $ 2.49 | $ 3.82 | |||||||||
Total grant date fair value of restricted stock units vested | $ 0 | $ 597,000 | $ 16,000 | |||||||||
Aggregate intrinsic value of stock options exercised | 0 | 1,000 | 80,000 | |||||||||
Aggregate intrinsic value of restricted stock units | 123,875 | $ 6,000 | $ 31,000 | |||||||||
Unrecognized share based compensation expense related to unvested stock options | 4,600,000 | |||||||||||
Unrecognized share based compensation expense related to restricted stock units | $ 200,000 | |||||||||||
Inducement Pool Non Qualified Option [Member] | ||||||||||||
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] | ||||||||||||
Number of common stock shares reserved for issuance | 300,000 | 300,000 | ||||||||||
Employee Stock Option [Member] | ||||||||||||
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] | ||||||||||||
Unrecognized cost expected to be recognized over a weighted average period | 2 years 3 months 18 days | |||||||||||
Restricted Stock Unit [Member] | ||||||||||||
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] | ||||||||||||
Unrecognized cost expected to be recognized over a weighted average period | 2 years | |||||||||||
2014 Plan [Member] | ||||||||||||
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] | ||||||||||||
Maximum term for stock option plan grant | 10 years | |||||||||||
Options vesting period | 4 years | |||||||||||
2015 Stock Option and Incentive Plan [Member] | ||||||||||||
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] | ||||||||||||
Maximum term for stock option plan grant | 10 years | |||||||||||
Options vesting period | 4 years | |||||||||||
Options vesting period, description | For an initial grant to an employee, 25% of the options generally vest on the first anniversary of the original vesting date, with the balance vesting monthly over the remaining three years. For subsequent grants to an employee, the options generally vest monthly over a four-year term. | |||||||||||
2015 Stock Option and Incentive Plan [Member] | One Year Anniversary [Member] | ||||||||||||
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] | ||||||||||||
Option vesting percentage | 25% | |||||||||||
Aspire Capital [Member] | ||||||||||||
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] | ||||||||||||
Number of shares issued and sold | 0 | 0 | 3,000,000 | |||||||||
Shares Issued, Price Per Share | $ 5.09 | |||||||||||
Proceeds from Issuance of Common Stock | $ 15,200,000 | |||||||||||
Long-term purchase commitment, description | upon the terms and subject to the conditions and limitations set forth therein, Aspire Capital was committed to purchase up to an aggregate of $20.0 million of shares of our common stock at our request from time to time during the 30 month term of the Purchase Agreement. | |||||||||||
Commitment to purchase shares | $ 20,000,000 | |||||||||||
Long-term purchase commitment, period | 30 months | |||||||||||
Public Offerings [Member] | ||||||||||||
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] | ||||||||||||
Proceeds from Issuance of Common Stock | $ 48,100,000 | $ 80,600,000 | ||||||||||
ATM Offering Program [Member] | H.C. Wainwright & Co., LLC [Member] | ||||||||||||
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] | ||||||||||||
Proceeds from Issuance of Common Stock | $ 9,600,000 | |||||||||||
Commission Rate Equal To Gross Proceeds1 | 3% | |||||||||||
ATM Offering Program [Member] | H.C. Wainwright & Co., LLC [Member] | Sale Agreement [Member] | ||||||||||||
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] | ||||||||||||
Agreed upon value of sale of common stock per transaction | $ 20,000,000 | |||||||||||
ATM Offering Program [Member] | H.C. Wainwright & Co., LLC [Member] | Sale Agreement [Member] | Maximum [Member] | ||||||||||||
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] | ||||||||||||
Agreed upon value of sale of common stock per transaction | $ 20,000,000 | $ 10,000,000 | ||||||||||
ATM Offering Program [Member] | Jefferies LLC [Member] | ||||||||||||
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] | ||||||||||||
Shares Issued, Price Per Share | $ 1.82 | $ 3.09 | ||||||||||
Proceeds from Issuance of Common Stock | $ 18,400,000 | $ 4,000,000 | ||||||||||
ATM Offering Program [Member] | Jefferies LLC [Member] | Sale Agreement [Member] | Maximum [Member] | ||||||||||||
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] | ||||||||||||
Agreed upon value of sale of common stock per transaction | $ 65,000,000 | |||||||||||
ATM Offering Program [Member] | Jones Trading Institutional Services LLC [Member] | ||||||||||||
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] | ||||||||||||
Shares Issued, Price Per Share | $ 6.07 | $ 6.07 | $ 4.75 | |||||||||
Proceeds from Issuance of Common Stock | $ 1,500,000 | $ 4,400,000 | ||||||||||
ATM Offering Program [Member] | Jones Trading Institutional Services LLC [Member] | Sale Agreement [Member] | Maximum [Member] | ||||||||||||
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] | ||||||||||||
Agreed upon value of sale of common stock per transaction | $ 25,000,000 | |||||||||||
IPO [Member] | 2015 Stock Option and Incentive Plan [Member] | ||||||||||||
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] | ||||||||||||
Number of common stock shares reserved for issuance | 3,964,555 | |||||||||||
IPO [Member] | 2015 Employee Stock Purchase Plan [Member] | ||||||||||||
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] | ||||||||||||
Number of common stock shares reserved for issuance | 727,311 | |||||||||||
Common Stock [Member] | Inducement Pool Non Qualified Option [Member] | ||||||||||||
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] | ||||||||||||
Options vesting period | 4 years | |||||||||||
Stock options granted | 23,400 | |||||||||||
Exercise price, granted | $ 2.26 | |||||||||||
Common Stock [Member] | One Year Anniversary [Member] | Inducement Pool Non Qualified Option [Member] | ||||||||||||
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] | ||||||||||||
Options vesting period | 1 year | |||||||||||
Option vesting percentage | 25% | |||||||||||
Common Stock [Member] | Share-Based Payment Arrangement, Tranche Two [Member] | Inducement Pool Non Qualified Option [Member] | ||||||||||||
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] | ||||||||||||
Options vesting period | 3 years | |||||||||||
Option vesting percentage | 75% | |||||||||||
Common Stock [Member] | Maximum [Member] | Inducement Pool Non Qualified Option [Member] | ||||||||||||
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] | ||||||||||||
Options vesting period | 10 years | |||||||||||
Common Stock [Member] | Public Offerings [Member] | ||||||||||||
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] | ||||||||||||
Number of shares issued and sold | 23,125,000 | 10,781,250 | ||||||||||
Shares Issued, Price Per Share | $ 2.25 | $ 8 | ||||||||||
Common Stock [Member] | ATM Offering Program [Member] | H.C. Wainwright & Co., LLC [Member] | ||||||||||||
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] | ||||||||||||
Number of shares issued and sold | 1,988,254 | |||||||||||
Shares Issued, Price Per Share | $ 4.99 | |||||||||||
Common Stock [Member] | ATM Offering Program [Member] | Jefferies LLC [Member] | ||||||||||||
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] | ||||||||||||
Number of shares issued and sold | 10,530,795 | 1,421,627 | ||||||||||
Common Stock [Member] | ATM Offering Program [Member] | Jones Trading Institutional Services LLC [Member] | ||||||||||||
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] | ||||||||||||
Number of shares issued and sold | 260,455 | 986,267 |
Stockholders' Equity - Summary
Stockholders' Equity - Summary of Stock Option Activity (Detail) | 12 Months Ended |
Dec. 31, 2023 $ / shares shares | |
Share-Based Payment Arrangement [Abstract] | |
Number of Outstanding Stock Options, Beginning Balance | shares | 2,956,170 |
Number of Outstanding Stock Options, Granted | shares | 1,112,885 |
Number of Outstanding Stock Options, Canceled/forfeited/expired | shares | (112,228) |
Number of Outstanding Stock Options, Ending Balance | shares | 3,956,827 |
Weighted Average Exercise Price, Beginning Balance | $ / shares | $ 7.45 |
Weighted Average Exercise Price, Granted | $ / shares | 2.21 |
Weighted Average Exercise Price, Canceled/forfeited/expired | $ / shares | 6.42 |
Weighted Average Exercise Price, Ending Balance | $ / shares | $ 6 |
Weighted Average Contractual Term, Outstanding | 7 years 11 months 8 days |
Stockholders' Equity - Summar_2
Stockholders' Equity - Summary of Assumptions Used to Determine Fair Value of Employee Stock Option Grants, Employee Stock Purchase Plan and Performance Options with Market Condition (Detail) | 12 Months Ended | ||
Dec. 31, 2023 | Dec. 31, 2022 | Dec. 31, 2021 | |
ESPP [Member] | |||
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] | |||
Expected term (in years) | 6 months | 6 months | 6 months |
Risk-free interest rate, minimum | 4.54% | 0.06% | 0.04% |
Risk-free interest rate, maximum | 5.38% | 4.54% | 0.12% |
Expected volatility, minimum | 40.90% | 51.90% | 89.70% |
Expected volatility, maximum | 58.50% | 95.90% | 108.12% |
Expected dividend yield | 0% | 0% | 0% |
Employee Stock Option [Member] | |||
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] | |||
Risk-free interest rate, minimum | 3.58% | 1.70% | 0.60% |
Risk-free interest rate, maximum | 4.50% | 4.20% | 1.30% |
Expected volatility, minimum | 81.50% | 84.20% | 86.30% |
Expected volatility, maximum | 83% | 86.50% | 104.80% |
Expected dividend yield | 0% | 0% | 0% |
Employee Stock Option [Member] | Minimum [Member] | |||
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] | |||
Expected term (in years) | 5 years 6 months 3 days | 5 years 11 months 23 days | 5 years 6 months |
Employee Stock Option [Member] | Maximum [Member] | |||
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] | |||
Expected term (in years) | 6 years 1 month 2 days | 6 years 29 days | 6 years 29 days |
Stockholders' Equity - Schedule
Stockholders' Equity - Schedule of Restricted Stock Unit Activity (Detail) - Restricted Stock Unit [Member] | 12 Months Ended |
Dec. 31, 2023 $ / shares shares | |
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items] | |
Number of Outstanding Restricted Stock Units, Beginning Balance | shares | 121,438 |
Number of Outstanding Restricted Stock Units, Released | shares | (58,111) |
Number of Outstanding Restricted Stock Units, Ending Balance | shares | 63,327 |
Weighted Average Grant Date Fair Value, Beginning Balance | $ / shares | $ 5.09 |
Weighted Average Grant Date Fair Value, Released | $ / shares | 4.69 |
Weighted Average Grant Date Fair Value, Ending Balance | $ / shares | $ 5.45 |
Stockholders' Equity - Schedu_2
Stockholders' Equity - Schedule of Allocation of Stock-Based Compensation for All Options Including Performance Options with Market Condition and Restricted Stock Units (Detail) - USD ($) $ in Thousands | 12 Months Ended | ||
Dec. 31, 2023 | Dec. 31, 2022 | Dec. 31, 2021 | |
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items] | |||
Total stock-based compensation expense | $ 2,600 | $ 2,154 | $ 1,614 |
Research and Development Expense [Member] | |||
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items] | |||
Total stock-based compensation expense | 600 | 528 | 295 |
General and Administrative Expense [Member] | |||
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items] | |||
Total stock-based compensation expense | $ 2,000 | $ 1,626 | $ 1,319 |
Stockholders' Equity - Summar_3
Stockholders' Equity - Summary of Warrants Outstanding (Detail) | 12 Months Ended |
Dec. 31, 2023 $ / shares shares | |
Warrant One [Member] | |
Class Of Warrant Or Right [Line Items] | |
Number Outstanding | 2,978 |
Exercise Price Per Share | $ / shares | $ 50.37 |
Expiration Date | 2024-06 |
Warrant Two [Member] | |
Class Of Warrant Or Right [Line Items] | |
Number Outstanding | 2,886 |
Exercise Price Per Share | $ / shares | $ 51.98 |
Expiration Date | 2024-12 |
Warrant Three [Member] | |
Class Of Warrant Or Right [Line Items] | |
Number Outstanding | 5,864 |
Stockholders' Equity - Summar_4
Stockholders' Equity - Summary of Common Stock Reserved for Future Issuance (Detail) | Dec. 31, 2023 shares |
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] | |
Number of common stock shares reserved for issuance | 8,813,251 |
Common Stock Warrants [Member] | |
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] | |
Number of common stock shares reserved for issuance | 5,864 |
Common Stock Options and Restricted Stock Units [Member] | |
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] | |
Number of common stock shares reserved for issuance | 4,020,154 |
Shares Available Under the 2015 Plan [Member] | |
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] | |
Number of common stock shares reserved for issuance | 3,964,555 |
Shares Available Under the 2022 Inducement Plan [Member] | |
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] | |
Number of common stock shares reserved for issuance | 95,367 |
Shares Available Under the Employee Stock Purchase Plan [Member] | |
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] | |
Number of common stock shares reserved for issuance | 727,311 |
Income Tax - Schedule of Pretax
Income Tax - Schedule of Pretax Losses for Domestic and Foreign Operations (Detail) - USD ($) $ in Thousands | 12 Months Ended | ||
Dec. 31, 2023 | Dec. 31, 2022 | Dec. 31, 2021 | |
Income Tax Disclosure [Abstract] | |||
United States | $ (49,967) | $ (45,086) | $ (33,316) |
Foreign | (428) | (254) | (458) |
Worldwide pre-tax loss | $ (50,395) | $ (45,340) | $ (33,774) |
Income Tax - Additional Informa
Income Tax - Additional Information (Detail) - USD ($) | 12 Months Ended | ||
Dec. 31, 2023 | Dec. 31, 2022 | Dec. 31, 2021 | |
Income Tax [Line Items] | |||
Income tax (benefit) provision | $ 0 | $ 0 | $ 0 |
Valuation allowance | 107,989,000 | 95,484,000 | |
Capitalized R&D costs | $ 44,200,000 | 38,800,000 | |
Period of change in ownership | 3 years | ||
Percentage of change in ownership | 50% | ||
Unrecognized tax benefits, income tax penalties and interest accrued | $ 0 | $ 0 | $ 0 |
Change in unrecognized tax benefits | $ 0 | ||
Federal [Member] | |||
Income Tax [Line Items] | |||
Amortization period of capitalized R&D costs | 5 years | ||
NOLs carryforwards | $ 257,400,000 | ||
NOLs carryforwards not subject to expiration | 144,900,000 | ||
NOLs carryforwards subject to expiration | $ 112,500,000 | ||
NOLs carryforwards expiration year | 2025 | ||
Research and development credit carryforward | $ 9,300,000 | ||
Research and development credit carryforward expiration year | 2026 | ||
Federal [Member] | Orphan Drug Credits [Member] | |||
Income Tax [Line Items] | |||
Research and development credit carryforward | $ 400,000 | ||
Research and development credit carryforward expiration year | 2035 | ||
State [Member] | |||
Income Tax [Line Items] | |||
NOLs carryforwards subject to expiration | $ 225,300,000 | ||
NOLs carryforwards expiration year | 2025 | ||
Research and development credit carryforward | $ 5,800,000 | ||
Foreign [Member] | |||
Income Tax [Line Items] | |||
Amortization period of capitalized R&D costs | 15 years | ||
NOLs carryforwards not subject to expiration | $ 9,400,000 |
Income Tax - Schedule of Reconc
Income Tax - Schedule of Reconciliations of the Expected Statutory Federal Income Tax (Detail) - USD ($) | 12 Months Ended | ||
Dec. 31, 2023 | Dec. 31, 2022 | Dec. 31, 2021 | |
Income Tax Disclosure [Abstract] | |||
Expected income taxes benefit at federal statutory rate | $ (10,583,000) | $ (9,521,000) | $ (7,093,000) |
State income taxes, net of federal benefit | (2,171,000) | (380,000) | (2,313,000) |
Permanent items and other | 172,000 | 438,000 | 592,000 |
Stock compensation | 91,000 | 44,000 | 90,000 |
Research credits | (5,336,000) | (4,415,000) | (1,253,000) |
Unrecognized tax benefits | 5,209,000 | 2,454,000 | 500,000 |
Foreign rate differential | 19,000 | 11,000 | 21,000 |
Change in tax rate | (5,000) | 34,000 | 52,000 |
Change in valuation allowance | 12,604,000 | 11,335,000 | 9,404,000 |
Income tax (benefit) expense | $ 0 | $ 0 | $ 0 |
Income Tax - Schedule of Signif
Income Tax - Schedule of Significant Components of Deferred Tax Assets (Detail) - USD ($) $ in Thousands | Dec. 31, 2023 | Dec. 31, 2022 |
Deferred tax assets: | ||
Net operating loss carryforwards | $ 60,090 | $ 52,752 |
Capitalized research and development expenses | 25,922 | 22,576 |
Research credits and other state credits | 18,246 | 16,021 |
Intangible assets | 1,093 | 1,278 |
Reserve and accruals | 522 | 596 |
Share-based compensation expense | 1,821 | 1,628 |
Lease liability | 1,709 | 2,157 |
Total tax assets | 109,403 | 97,008 |
Valuation allowance | (107,989) | (95,484) |
Total deferred tax assets | 1,414 | 1,524 |
Deferred tax liabilities: | ||
Right of use lease assets | (1,414) | (1,524) |
Total deferred tax liabilities | $ (1,414) | $ (1,524) |
Income Tax - Schedule of Activi
Income Tax - Schedule of Activity Related to Unrecognized Tax Benefits (Detail) - USD ($) $ in Thousands | 12 Months Ended | ||
Dec. 31, 2023 | Dec. 31, 2022 | Dec. 31, 2021 | |
Income Tax Disclosure [Abstract] | |||
Balance as of beginning of year | $ 25,145 | $ 22,232 | $ 21,707 |
Increase (decrease) related to prior year tax positions | (483) | (48) | (9) |
Increase related to current year tax positions | 5,416 | 2,961 | 534 |
Balance as of end of year | $ 30,078 | $ 25,145 | $ 22,232 |
Employee Benefits - Additional
Employee Benefits - Additional Information (Detail) - 401 (k) Plan [Member] - USD ($) $ in Millions | 12 Months Ended | ||
Dec. 31, 2023 | Dec. 31, 2022 | Dec. 31, 2021 | |
Defined Contribution Plan Disclosure [Line Items] | |||
Policy approved month and year | 2015-04 | ||
Date of Policy beginning | Jun. 01, 2015 | ||
Percentage of match employee contribution | 50% | ||
Percentage of participants's annual salary | 6% | ||
Discretionary contribution | $ 0.2 | $ 0.2 | $ 0.2 |