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 accumulated 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 AgreementSM 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

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.

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 accumulated 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 AgreementSM 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.

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.