Document and Entity Information
Document and Entity Information - shares | 3 Months Ended | |
Mar. 31, 2024 | May 03, 2024 | |
Cover [Abstract] | ||
Document Type | 10-Q | |
Document Quarterly Report | true | |
Document Transition Report | false | |
Document Period End Date | Mar. 31, 2024 | |
Entity File Number | 001-35005 | |
Entity Registrant Name | ASSEMBLY BIOSCIENCES, INC. | |
Entity Incorporation, State or Country Code | DE | |
Entity Tax Identification Number | 20-8729264 | |
Entity Address, Address Line One | Two Tower Place | |
Entity Address, Address Line Two | 7th Floor | |
Entity Address, City or Town | South San Francisco | |
Entity Address, State or Province | CA | |
Entity Address, Postal Zip Code | 94080 | |
City Area Code | 833 | |
Local Phone Number | 509-4583 | |
Amendment Flag | false | |
Document Fiscal Year Focus | 2024 | |
Document Fiscal Period Focus | Q1 | |
Entity Central Index Key | 0001426800 | |
Current Fiscal Year End Date | --12-31 | |
Entity Current Reporting Status | Yes | |
Entity Interactive Data Current | Yes | |
Entity Filer Category | Non-accelerated Filer | |
Trading Symbol | ASMB | |
Security Exchange Name | NASDAQ | |
Title of 12(b) Security | Common Stock, par value $0.001 | |
Entity Common Stock, Shares Outstanding | 5,513,308 | |
Entity Shell Company | false | |
Entity Emerging Growth Company | false | |
Entity Small Business | true |
CONDENSED CONSOLIDATED BALANCE
CONDENSED CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands | Mar. 31, 2024 | Dec. 31, 2023 |
Current assets | ||
Cash and cash equivalents | $ 18,749 | $ 19,841 |
Marketable securities | 94,227 | 110,406 |
Accounts receivable from collaboration | 43 | 43 |
Prepaid expenses and other current assets | 4,149 | 3,497 |
Total current assets | 117,168 | 133,787 |
Property and equipment, net | 367 | 385 |
Operating lease right-of-use (ROU) assets | 2,036 | 2,339 |
Other assets | 312 | 312 |
Total assets | 119,883 | 136,823 |
Current liabilities | ||
Accounts payable | 727 | 461 |
Accrued research and development expenses | 2,059 | 885 |
Other accrued expenses | 2,051 | 5,744 |
Deferred revenue from a related party - short-term | 32,771 | 30,915 |
Operating lease liabilities - short-term | 1,145 | 1,220 |
Total current liabilities | 38,753 | 39,225 |
Deferred revenue from a related party - long-term | 47,738 | 55,379 |
Operating lease liabilities - long-term | 791 | 1,122 |
Total liabilities | 87,282 | 95,726 |
Commitments and contingencies | ||
Stockholders' equity | ||
Preferred stock, $0.001 par value; 5,000,000 shares authorized; no shares issued or outstanding | ||
Common stock, $0.001 par value; 150,000,000 shares authorized as of March 31, 2024 and December 31, 2023; 5,482,752 shares issued and outstanding as of March 31, 2024 and December 31, 2023 | 5 | 5 |
Additional paid-in capital | 827,660 | 826,921 |
Accumulated other comprehensive loss | (239) | (81) |
Accumulated deficit | (794,825) | (785,748) |
Total stockholders' equity | 32,601 | 41,097 |
Total liabilities and stockholders' equity | $ 119,883 | $ 136,823 |
CONDENSED CONSOLIDATED BALANC_2
CONDENSED CONSOLIDATED BALANCE SHEETS (Parenthetical) - $ / shares | Mar. 31, 2024 | Dec. 31, 2023 |
Statement of Financial Position [Abstract] | ||
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 | 150,000,000 | 150,000,000 |
Common stock, shares issued | 5,482,752 | 5,482,752 |
Common stock, shares outstanding | 5,482,752 | 5,482,752 |
CONDENSED CONSOLIDATED STATEMEN
CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS AND COMPREHENSIVE LOSS - USD ($) $ in Thousands | 3 Months Ended | |
Mar. 31, 2024 | Mar. 31, 2023 | |
Income Statement [Abstract] | ||
Collaboration revenue from a related party | $ 5,785 | $ 0 |
Operating expenses | ||
Research and development | 11,879 | 14,547 |
General and administrative | 4,635 | 5,012 |
Total operating expenses | 16,514 | 19,559 |
Loss from operations | (10,729) | (19,559) |
Other income | ||
Interest and other income, net | 1,652 | 609 |
Total other income | 1,652 | 609 |
Net loss | (9,077) | (18,950) |
Other comprehensive loss | ||
Unrealized (loss) gain on marketable securities | (158) | 290 |
Comprehensive loss | $ (9,235) | $ (18,660) |
Net loss per share, basic | $ (1.66) | $ (4.46) |
Net loss per share, diluted | $ (1.66) | $ (4.46) |
Weighted average common shares outstanding, basic | 5,483,313 | 4,251,037 |
Weighted average common shares outstanding, diluted | 5,483,313 | 4,251,037 |
CONDENSED CONSOLIDATED STATEM_2
CONDENSED CONSOLIDATED STATEMENTS OF CHANGES IN STOCKHOLDERS' EQUITY - USD ($) $ in Thousands | Total | Common Stock | Additional Paid-in Capital | Accumulated Other Comprehensive Loss | Accumulated Deficit |
Balance at Dec. 31, 2022 | $ 82,664 | $ 4 | $ 807,983 | $ (803) | $ (724,520) |
Balance (in shares) at Dec. 31, 2022 | 4,074,552 | ||||
Issuance of common stock under at-the-market (ATM) equity offering program, net of issuance costs | 4,492 | 4,492 | |||
Issuance of common stock under at-the-market (ATM) equity offering program, net of issuance costs (in shares) | 254,203 | ||||
Issuance of common stock for settlement of restricted stock units (RSUs) (in shares) | 5,820 | ||||
Unrealized gain (loss) on marketable debt securities | 290 | 290 | |||
Stock-based compensation | 1,837 | 1,837 | |||
Net loss | (18,950) | (18,950) | |||
Balance at Mar. 31, 2023 | 70,333 | $ 4 | 814,312 | (513) | (743,470) |
Balance (in shares) at Mar. 31, 2023 | 4,334,575 | ||||
Balance at Dec. 31, 2023 | 41,097 | $ 5 | 826,921 | (81) | (785,748) |
Balance (in shares) at Dec. 31, 2023 | 5,482,752 | ||||
Unrealized gain (loss) on marketable debt securities | (158) | (158) | |||
Stock-based compensation | 739 | 739 | |||
Net loss | (9,077) | (9,077) | |||
Balance at Mar. 31, 2024 | $ 32,601 | $ 5 | $ 827,660 | $ (239) | $ (794,825) |
Balance (in shares) at Mar. 31, 2024 | 5,482,752 |
CONDENSED CONSOLIDATED STATEM_3
CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands | 3 Months Ended | |
Mar. 31, 2024 | Mar. 31, 2023 | |
Cash flows from operating activities | ||
Net loss | $ (9,077) | $ (18,950) |
Adjustments to reconcile net loss to net cash used in operating activities: | ||
Depreciation and amortization | 32 | 124 |
Stock-based compensation | 739 | 1,835 |
Net accretion of investments in marketable debt securities | (1,264) | (52) |
Non-cash rent expense | 359 | 855 |
Changes in operating assets and liabilities: | ||
Accounts receivable from collaboration | 0 | 227 |
Prepaid expenses and other current assets | (652) | (1,598) |
Other assets | 0 | 555 |
Accounts payable | 266 | (1,269) |
Accrued research and development expenses | 1,174 | (76) |
Other accrued expenses | (3,693) | (4,161) |
Deferred revenue from a related party | (5,785) | 0 |
Operating lease liabilities | (463) | (918) |
Net cash used in operating activities | (18,364) | (23,428) |
Cash flows from investing activities | ||
Proceeds from maturities of marketable securities | 21,000 | 10,000 |
Purchases of property and equipment | (14) | 0 |
Purchases of marketable securities | (3,714) | 0 |
Net cash provided by investing activities | 17,272 | 10,000 |
Cash flows from financing activities | ||
Proceeds from the issuance of common stock under ATM equity offering program, net of issuance costs | 0 | 4,492 |
Net cash provided by financing activities | 0 | 4,492 |
Net decrease in cash and cash equivalents | (1,092) | (8,936) |
Cash and cash equivalents at the beginning of the period | 19,841 | 52,418 |
Cash and cash equivalents at the end of the period | $ 18,749 | $ 43,482 |
Nature of Business
Nature of Business | 3 Months Ended |
Mar. 31, 2024 | |
Organization, Consolidation and Presentation of Financial Statements [Abstract] | |
Nature of Business | Note 1 - Nature of Business Overview Assembly Biosciences, Inc. (together with its subsidiaries, Assembly or the Company), incorporated in Delaware in October 2005, is a biotechnology company developing innovative therapeutics. The Company's pipeline includes two helicase-primase inhibitors (HPI) targeting recurrent genital herpes, an orally bioavailable hepatitis delta virus (HDV) entry inhibitor, a clinical stage capsid assembly modulator candidate designed to disrupt the replication cycle of hepatitis B virus (HBV) and research programs focused on a non-nucleoside polymerase inhibitor (NNPI) targeting transplant-related herpesviruses and a small molecule interferon-α (IFN-α) receptor (IFNAR) agonist targeting HBV and HDV. The Company operates in one segment and is headquartered in South San Francisco, California. Liquidity The Company has not derived any revenue from product sales to date and currently has no approved products. Once a product has been developed, it will need to be approved for sale by the U.S. Food and Drug Administration (FDA) or an applicable foreign regulatory agency. Since inception, the Company’s operations have been financed through the sale of equity securities, the proceeds from the exercise of warrants and stock options, the issuance of debt, and upfront payments related to collaboration agreements. The Company has incurred losses from operations since inception and expects to continue to incur substantial losses for the next several years as it continues its product development efforts. Management believes the Company currently has sufficient funds to meet its operating requirements for at least the next twelve months following the date these unaudited condensed consolidated financial statements are issued. |
Summary of Significant Accounti
Summary of Significant Accounting Policies | 3 Months Ended |
Mar. 31, 2024 | |
Accounting Policies [Abstract] | |
Summary of Significant Accounting Policies | Note 2 - Summary of Significant Accounting Policies Basis of Presentation The accompanying unaudited condensed consolidated financial statements include the accounts of the Company and its subsidiaries. All intercompany balances and transactions have been eliminated in consolidation. The accompanying unaudited condensed consolidated financial statements have been prepared in accordance with the accounting principles generally accepted in the United States of America (U.S. GAAP) for interim financial information and pursuant to the instructions to Form 10-Q and Rule 10-01 of Regulation S-X of the SEC. In management’s opinion, the unaudited condensed consolidated financial statements have been prepared on the same basis as the annual audited consolidated financial statements and include normal recurring adjustments necessary for the fair presentation of the Company’s financial position and its results of operations and comprehensive loss and its cash flows for the periods presented. These statements do not include all disclosures required by U.S. GAAP and should be read in conjunction with the Company’s audited consolidated financial statements and accompanying notes for the fiscal year ended December 31, 2023, which are contained in the 2023 Annual Report. The results for the three months ended March 31, 2024 are not necessarily indicative of results to be expected for the entire year ending December 31, 2024 or future operating periods. Use of Estimates The preparation of the unaudited condensed consolidated financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that may affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and reported amounts of expenses during the reporting period. Actual results could differ from those estimates. Significant estimates inherent in the preparation of the accompanying unaudited condensed consolidated financial statements include estimates for revenue recognition and costs incurred but not yet invoiced for research and development accruals. The Company’s estimates could be affected by external conditions, including those unique to the Company and general economic conditions. It is reasonably possible these external factors could have an effect on the Company’s estimates and could cause actual results to differ materially from those estimates and assumptions. Other Risks and Uncertainties U.S. and global financial markets have experienced volatility and disruption due to macroeconomic and geopolitical events such as rising inflation, rising interest rates to combat inflation, the risk of a recession, the war between Russia and Ukraine and the Israel-Hamas war. The Company cannot predict at this time to what extent, if at all, it and its employees, CROs, vendors and/or collaborators could potentially be negatively impacted by these events. Reverse Stock Split In September 2023, the Company received a letter from the Listing Qualifications Department of the Nasdaq Stock Market notifying the Company, as the bid price for its common stock had closed below $ 1.00 per share for the last 30 consecutive business days, it was not in compliance with Nasdaq Listing Rule 5450(a)(1), which is the minimum bid price requirement for continued listing on the Nasdaq Global Select Market. In accordance with Nasdaq Listing Rule 5810(c)(3)(A), the Company was provided a 180-calendar day period, or until March 25, 2024, to regain compliance with the minimum bid price requirement. The continued listing standard would be met once the closing bid price of the Company’s common stock was at least $ 1.00 per share for a minimum of ten consecutive business days during the 180-calendar day period. In January 2024, the Company's stockholders approved a reverse stock split of its common stock at a range of ratios between 1-for-7 to 1-for-17 , and the Company's board of directors approved the implementation of the reverse stock split at a ratio of 1-for-12 (the Reverse Stock Split). The Reverse Stock Split was effective as of February 9, 2024 and the Company regained compliance with the minimum bid price requirement in February 2024. As of the effective time of the Reverse Stock Split, every 12 issued and outstanding shares of the Company’s common stock was automatically reclassified into one issued and outstanding share of the Company’s common stock. This reduced the number of shares outstanding from 65.8 million shares to 5.5 million shares. The Reverse Stock Split did not affect the number of authorized shares of common stock or the par value of the common stock. No fractional shares of common stock were issued in connection with the Reverse Stock Split and all fractional shares were rounded down to the nearest whole share with respect to outstanding shares of common stock. Any holders of common stock who would have otherwise received a fractional share of common stock pursuant to the Reverse Stock Split, received cash in lieu of the fractional share. All prior period share and per share amounts of the Company's common stock presented have been retroactively adjusted to reflect the 1-for-12 Reverse Stock Split, including reclassifying an amount equal to the reduction in par value of common stock to additional paid-in capital. Net Loss per Share Basic net loss per share of common stock excludes dilution and is computed by dividing net loss by the weighted average number of shares of common stock outstanding during the period. Diluted net loss per share of common stock reflects the potential dilution that could occur if securities or other contracts to issue common stock were exercised or converted into common stock or resulted in the issuance of common stock that then shared in the earnings of the entity unless inclusion of such shares would be anti-dilutive. Diluted net loss per share is the same as basic net loss per share, since the effects of potentially dilutive securities are antidilutive given the net loss for each period presented. A reconciliation of the numerators and the denominators of the basic and diluted net loss per common share computations is as follows (in thousands, except for share and per share amounts): Three Months Ended March 31, 2024 2023 Numerator: Net loss $ ( 9,077 ) $ ( 18,950 ) Denominator: Weighted average common shares outstanding - basic and diluted 5,483,313 4,251,037 Net loss per share - basic and diluted $ ( 1.66 ) $ ( 4.46 ) Securities excluded from the computation of diluted net loss per share because including them would have been antidilutive are as follows: March 31, 2024 2023 Options to purchase common stock 1,026,696 876,272 Common stock subject to purchase under Employee Stock Purchase Plan 7,545 7,740 Unvested RSUs 103,752 143,110 Total 1,137,993 1,027,122 |
Related Party
Related Party | 3 Months Ended |
Mar. 31, 2024 | |
Related Party Transactions [Abstract] | |
Related Party | Note 3 – Related Party In October 2023, the Company entered into an Option, License and Collaboration agreement (the Gilead Collaboration Agreement), and a Common Stock Purchase Agreement and an Investor Rights Agreement (collectively, the Gilead Equity Agreements) under which it received total proceeds of $ 100.0 million from Gilead Sciences, Inc. (Gilead) . During the three months ended March 31, 2024, the Company recognized $ 5.8 million of collaboration revenue under the Gilead Collaboration Agreement (see Note 8). As of March 31, 2024 , Gilead held 19.9 % of the Company's outstanding voting common stock. Additionally, Gilead may, at the Company’s or Gilead's option, subject to certain conditions, purchase additional shares to increase its holdings up to a maximum of 29.9 % of the Company's then-outstanding voting common stock. Under the Investor Rights Agreement, Gilead has the right to designate two directors to the Company's board of directors. The Company appointed each of Gilead's designees to its board of directors in December 2023 and February 2024. |
Fair Value Measurements and Inv
Fair Value Measurements and Investments in Marketable Securities | 3 Months Ended |
Mar. 31, 2024 | |
Investments, Debt and Equity Securities [Abstract] | |
Fair Value Measurements and Investments in Marketable Securities | Note 4 – Fair Value Measurements and Investments in Marketable Securities The carrying amounts of cash equivalents and marketable securities approximate their fair value based upon quoted market prices. Certain of the Company’s financial instruments are not measured at fair value on a recurring basis, but are recorded at amounts that approximate their fair value due to their liquid or short-term nature, such as cash, accounts receivable, accounts payable and accrued expenses. The Company uses the following three-level hierarchy that maximizes the use of observable inputs and minimizes the use of unobservable inputs to value its financial instruments: Level 1: Observable inputs such as unadjusted quoted prices in active markets for identical instruments. Level 2: Quoted prices for similar instruments that are directly or indirectly observable in the marketplace. Level 3: Significant unobservable inputs that are supported by little or no market activity and that are financial instruments whose values are determined using pricing models, discounted cash flow methodologies, or similar techniques, as well as instruments for which the determination of fair value requires significant judgment or estimation. Investments in marketable securities consisted of the following (in thousands): March 31, 2024 Amortized Gross Gross Fair Value Cash equivalents Money market fund $ 18,110 $ — $ — $ 18,110 Total cash equivalents 18,110 — — 18,110 Short-term marketable securities U.S. and foreign corporate debt securities 17,764 12 — 17,776 U.S. treasury securities 60,471 20 ( 6 ) 60,485 U.S. and foreign commercial paper 15,958 11 ( 3 ) 15,966 Total short-term marketable securities 94,193 43 ( 9 ) 94,227 Total cash equivalents and marketable securities $ 112,303 $ 43 $ ( 9 ) $ 112,337 December 31, 2023 Amortized Gross Gross Fair Value Cash equivalents Money market fund $ 18,982 $ — $ — $ 18,982 Total cash equivalents 18,982 — — 18,982 Short-term marketable securities U.S. and foreign corporate debt securities 17,595 41 ( 3 ) 17,633 U.S. treasury securities 76,891 127 — 77,018 U.S. and foreign commercial paper 15,728 27 — 15,755 Total short-term marketable securities 110,214 195 ( 3 ) 110,406 Total cash equivalents and marketable securities $ 129,196 $ 195 $ ( 3 ) $ 129,388 There were no realized gains and losses for the three months ended March 31, 2024 and 2023 . As of March 31, 2024 and 2023, investments which were in an unrealized loss position were not material and generally due to interest rate fluctuations, as opposed to declines in credit quality. The Company determined it has the intent and ability to hold all marketable securities that have been in a continuous loss position until recovery of their amortized cost basis, which may be until maturity. As a result, the Company did not recognize any credit losses related to its investments and all unrealized gains and losses on available-for-sale securities are recorded in accumulated other comprehensive loss on the condensed consolidated balance sheets during the three months ended March 31, 2024 and 2023. Accrued interest receivable was $ 0.3 million as of March 31, 2024 and December 31, 2023 and was recorded in prepaid expenses and other current assets on the condensed consolidated balance sheets. The Company did not write off any accrued interest receivable during the three months ended March 31, 2024 and 2023. The following tables present the fair value of the Company’s financial assets measured at fair value on a recurring basis (in thousands): March 31, 2024 Level 1 Level 2 Level 3 Fair Value Cash equivalents Money market fund $ 18,110 $ — $ — $ 18,110 Total cash equivalents 18,110 — — 18,110 Short-term marketable securities U.S. and foreign corporate debt securities — 17,776 — 17,776 U.S. treasury securities — 60,485 — 60,485 U.S. and foreign commercial paper — 15,966 — 15,966 Total short-term marketable securities — 94,227 — 94,227 Total assets measured at fair value $ 18,110 $ 94,227 $ — $ 112,337 December 31, 2023 Level 1 Level 2 Level 3 Fair Value Cash equivalents Money market fund $ 18,982 $ — $ — $ 18,982 Total cash equivalents 18,982 — — 18,982 Short-term marketable securities U.S. and foreign corporate debt securities — 17,633 — 17,633 U.S. treasury securities — 77,018 — 77,018 U.S. and foreign commercial paper — 15,755 — 15,755 Total short-term marketable securities — 110,406 — 110,406 Total assets measured at fair value $ 18,982 $ 110,406 $ — $ 129,388 The Company estimates the fair value of its investments in marketable securities by taking into consideration valuations obtained from third-party pricing services. The pricing services utilize industry standard valuation models, including both income and market-based approaches, for which all significant inputs are observable, either directly or indirectly, to estimate fair value. These inputs include reported trades of and broker/dealer quotes on the same or similar securities, issuer credit spreads, benchmark securities, prepayment/default projections based on historical data, and other observable inputs. There were no transfers between Level 1, Level 2 or Level 3 investments during the periods presented. |
Other Accrued Expenses
Other Accrued Expenses | 3 Months Ended |
Mar. 31, 2024 | |
Payables and Accruals [Abstract] | |
Other Accrued Expenses | Note 5 – Other Accrued Expenses Other accrued expenses consist of the following (in thousands): March 31, December 31, Accrued expenses: Accrued compensation $ 1,727 $ 5,484 Accrued professional fees and other 324 260 Total accrued expenses $ 2,051 $ 5,744 |
Sale of Common Stock
Sale of Common Stock | 3 Months Ended |
Mar. 31, 2024 | |
Equity [Abstract] | |
Sale of Common Stock | Note 6 – Sale of Common Stock In August 2020, the Company entered into a sales agreement under which the Company may offer and sell shares of its common stock having an aggregate offering price of up to $ 100.0 million through “at-the-market” offerings (2020 ATM), pursuant to its shelf registration statement on Form S-3 on file with the SEC. The Company did no t sell any shares of common stock under the 2020 ATM during the three months ended March 31, 2024. During the three months ended March 31, 2023, the Company sold 254,203 shares of common stock under the 2020 ATM, for which the Company received net proceeds of $ 4.5 million , after deducting commissions, fees and expenses. |
Stock-Based Compensation
Stock-Based Compensation | 3 Months Ended |
Mar. 31, 2024 | |
Share-Based Payment Arrangement [Abstract] | |
Stock-Based Compensation | Note 7 – Stock-Based Compensation The following table summarizes the components of total stock-based compensation expense included in the condensed consolidated statements of operations and comprehensive loss (in thousands): Three Months Ended March 31, 2024 2023 Research and development $ 354 $ 910 General and administrative 385 925 Total stock-based compensation expense $ 739 $ 1,835 As of March 31, 2024, there was $ 4.2 million of total unrecognized stock-based compensation related to outstanding equity awards, which is expected to be recognized over a weighted average remaining amortization period of 1.9 years. The fair value of stock options granted during the periods indicated was estimated using the Black-Scholes option pricing model, based on the following assumptions: Three Months Ended March 31, 2024 2023 Exercise price $ 13.30 $ 10.68 - $ 18.36 Expected volatility 80.4 % - 86.9 % 77.5 % - 82.8 % Risk-free rate 4.16 % 3.59 % - 4.00 % Expected term (years) 5.5 - 7.0 5.5 - 7.0 Expected dividend yield 0 % 0 % |
Collaboration Agreements
Collaboration Agreements | 3 Months Ended |
Mar. 31, 2024 | |
Collaboration Agreement [Abstract] | |
Collaboration Agreements | Note 8 - Collaboration Agreements Gilead Agreement In October 2023, the Company entered into the Gilead Collaboration Agreement and the Gilead Equity Agreements under which it received total proceeds of $ 100.0 million. Under the Gilead Collaboration Agreement, Gilead exclusively licensed to the Company its HPI program and NNPI program, while retaining opt-in rights to these programs and have an option to take an exclusive license, on a program-by-program basis, to all of the Company’s other current and future pipeline programs. During the 12-year collaboration term (subject to payment of certain extension fees) and for a specified period thereafter, Gilead may exercise its opt-in rights, on a program-by-program basis, at one of two timepoints—completion of a certain Phase 1 study or completion of a certain Phase 2 study for the first product within the program—upon payment of an opt-in fee ranging from $ 45.0 million to $ 125.0 million per program depending on the type of program and when the option is exercised. If Gilead exercises its opt-in right to any current or future program under the collaboration, the Company is eligible to receive up to $ 330.0 million in potential regulatory and commercial milestones on that program, in addition to royalties ranging from the high single-digits to high teens, depending on the clinical stage of the program at the time of the opt-in. Following Gilead’s exercise of its option for each of the Company’s programs, the Company may opt in to cover 40 % of the research and development costs in the United States and share 40 % of the profits and operating loss in the United States for products within the program in lieu of receiving milestones and royalties for that program in the United States, unless the Company later opts out of the cost/profit share for the program. Prior to Gilead’s potential exercise of its opt-in, the Company will be primarily responsible for all discovery, research and development on its programs and the two Gilead-contributed programs. Following Gilead’s opt-in, Gilead will control the further discovery, research, development, and commercialization on any optioned programs. During the term, Gilead will continue to support the collaboration through extension fees of $ 75.0 million in each of the third, fifth and seventh years of the collaboration. The Gilead Collaboration Agreement is subject to termination by either party for the other party’s uncured, material breach or insolvency. Subject to certain limitations, the Company and Gilead both have certain termination for convenience rights, upon sufficient prior written notice, with respect to programs that one party in-licenses from the other (subject to Gilead’s option rights), and with respect to Gilead, for programs it has option rights to (subject to certain time limitations with respect to existing Company programs). Gilead also has a right to terminate the collaborative activities under the Gilead Collaboration Agreement at certain specified points during the collaboration term. Other customary termination rights are further provided in the Gilead Collaboration Agreement. The Company concluded Gilead is a customer and accordingly, the Gilead Collaboration Agreement is within the scope of the revenue from contracts with customers guidance. The Company identified a single combined performance obligation for the discovery, research and development services during the collaboration term (the R&D Services). As of March 31, 2024 , the total transaction price of the Gilead Collaboration Agreement was determined to be $ 90.7 million. The Company will reevaluate the transaction price in each reporting period as uncertain events are resolved or other changes in circumstances occur. The transaction price is reflected as collaboration revenue when realized in the Company’s condensed consolidated statements of operations. The Company will recognize revenue over time using a cost-based input method over the initial non-cancellable term of three years since this method best reflects the transfer of services to Gilead. In applying a cost-based input method of revenue recognition, the Company uses actual costs incurred relative to estimated total costs to fulfill each performance obligation. The Company recognized collaboration revenue of $ 5.8 million during the three months ended March 31, 2024. The transaction price for future collaborative activities was recorded as deferred revenue on the condensed consolidated balance sheet as of March 31, 2024, of which $ 32.8 million was short-term and $ 47.7 million was long-term. During the three months ended March 31, 2024 , the Company incurred $ 0.2 million in reimbursable expenses due to Gilead. The following table presents changes in the Company’s contract liabilities (in thousands): Balance at Additions Deductions Balance at Three Months Ended March 31, 2024 Contract liabilities: Deferred revenue $ 86,294 $ — $ ( 5,785 ) $ 80,509 Three Months Ended March 31, 2024 2023 Collaboration revenue recognized in the period from Amounts included in deferred revenue at the beginning of the period $ 5,785 $ — Performance obligations satisfied in previous period $ — $ — Arbutus Biopharma Agreement In August 2020, the Company and Arbutus Biopharma Corporation (Arbutus Biopharma) entered into a Clinical Trial Collaboration Agreement (the Arbutus Biopharma Agreement) to conduct a randomized, multi-center, open-label Phase 2 clinical trial to explore the safety, pharmacokinetics and antiviral activity of the triple combination of vebicorvir (VBR), AB-729 and a nucleos(t)ide analog reverse transcriptase inhibitor (NrtI) compared to the double combinations of VBR with a NrtI and AB-729 with a NrtI. Under the Arbutus Biopharma Agreement, Assembly and Arbutus Biopharma share responsibility for the costs of the trial equally, excluding manufacturing supply which are the burden of each company to supply their respective drugs, VBR and AB-729. Assembly is responsible for conducting this clinical trial with Arbutus Biopharma reimbursing Assembly its share of expenses. In February 2023, Assembly and Arbutus Biopharma decided to terminate the Phase 2 clinical trial early, at the end of the 48-week on-treatment period, and are in the process of completing the final reconciliation of costs. Reimbursements and cost-sharing portions from Arbutus Biopharma are reflected as a reduction of research and development expense when realized in the Company’s condensed consolidated statements of operations. There were no costs incurred under the Arbutus Biopharma Agreement during the three months ended March 31, 2024. During the three months ended March 31, 2023, the Company recognized a reduction of research and development expenses of $ 0.6 million under the Arbutus Biopharma Agreement. |
Milestones and Research Agreeme
Milestones and Research Agreements | 3 Months Ended |
Mar. 31, 2024 | |
Milestones And Research Agreements [Abstract] | |
Milestones and Research Agreements | Note 9 - Milestones and Research Agreements HBV Research Agreement with Indiana University Since September 2013, the Company was party to an exclusive License Agreement dated September 3, 2013 with Indiana University Research and Technology Corporation (IURTC) from whom it licensed aspects of the Company’s HBV program held by IURTC. The license agreement required the Company to make milestone payments based upon the successful accomplishment of clinical and regulatory milestones. The aggregate amount of all performance milestone payments under the IURTC license agreement, if all milestones through development were met, was $ 0.8 million, with a portion having been paid. The Company was obligated to pay IURTC royalty payments based on net sales of the licensed technology as well as a portion of any sublicensing revenue Assembly received. The Company was also required to pay diligence maintenance fees each year to the extent that the royalty, sublicensing, and milestone payments to IURTC were less than such fees for that year. In February 2024, following its decision to discontinue further development or partnering for ABI-H3733, the Company terminated the IURTC license agreement, which became effective April 2024. The Company paid IURTC $ 0.1 million in diligence maintenance fees during both the three months ended March 31, 2024 and 2023 . |
Summary of Significant Accoun_2
Summary of Significant Accounting Policies (Policies) | 3 Months Ended |
Mar. 31, 2024 | |
Accounting Policies [Abstract] | |
Basis of Presentation | Basis of Presentation The accompanying unaudited condensed consolidated financial statements include the accounts of the Company and its subsidiaries. All intercompany balances and transactions have been eliminated in consolidation. The accompanying unaudited condensed consolidated financial statements have been prepared in accordance with the accounting principles generally accepted in the United States of America (U.S. GAAP) for interim financial information and pursuant to the instructions to Form 10-Q and Rule 10-01 of Regulation S-X of the SEC. In management’s opinion, the unaudited condensed consolidated financial statements have been prepared on the same basis as the annual audited consolidated financial statements and include normal recurring adjustments necessary for the fair presentation of the Company’s financial position and its results of operations and comprehensive loss and its cash flows for the periods presented. These statements do not include all disclosures required by U.S. GAAP and should be read in conjunction with the Company’s audited consolidated financial statements and accompanying notes for the fiscal year ended December 31, 2023, which are contained in the 2023 Annual Report. The results for the three months ended March 31, 2024 are not necessarily indicative of results to be expected for the entire year ending December 31, 2024 or future operating periods. |
Use of Estimates | Use of Estimates The preparation of the unaudited condensed consolidated financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that may affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and reported amounts of expenses during the reporting period. Actual results could differ from those estimates. Significant estimates inherent in the preparation of the accompanying unaudited condensed consolidated financial statements include estimates for revenue recognition and costs incurred but not yet invoiced for research and development accruals. The Company’s estimates could be affected by external conditions, including those unique to the Company and general economic conditions. It is reasonably possible these external factors could have an effect on the Company’s estimates and could cause actual results to differ materially from those estimates and assumptions. |
Other Risks and Uncertainties | Other Risks and Uncertainties U.S. and global financial markets have experienced volatility and disruption due to macroeconomic and geopolitical events such as rising inflation, rising interest rates to combat inflation, the risk of a recession, the war between Russia and Ukraine and the Israel-Hamas war. The Company cannot predict at this time to what extent, if at all, it and its employees, CROs, vendors and/or collaborators could potentially be negatively impacted by these events. |
Reverse Stock Split | Reverse Stock Split In September 2023, the Company received a letter from the Listing Qualifications Department of the Nasdaq Stock Market notifying the Company, as the bid price for its common stock had closed below $ 1.00 per share for the last 30 consecutive business days, it was not in compliance with Nasdaq Listing Rule 5450(a)(1), which is the minimum bid price requirement for continued listing on the Nasdaq Global Select Market. In accordance with Nasdaq Listing Rule 5810(c)(3)(A), the Company was provided a 180-calendar day period, or until March 25, 2024, to regain compliance with the minimum bid price requirement. The continued listing standard would be met once the closing bid price of the Company’s common stock was at least $ 1.00 per share for a minimum of ten consecutive business days during the 180-calendar day period. In January 2024, the Company's stockholders approved a reverse stock split of its common stock at a range of ratios between 1-for-7 to 1-for-17 , and the Company's board of directors approved the implementation of the reverse stock split at a ratio of 1-for-12 (the Reverse Stock Split). The Reverse Stock Split was effective as of February 9, 2024 and the Company regained compliance with the minimum bid price requirement in February 2024. As of the effective time of the Reverse Stock Split, every 12 issued and outstanding shares of the Company’s common stock was automatically reclassified into one issued and outstanding share of the Company’s common stock. This reduced the number of shares outstanding from 65.8 million shares to 5.5 million shares. The Reverse Stock Split did not affect the number of authorized shares of common stock or the par value of the common stock. No fractional shares of common stock were issued in connection with the Reverse Stock Split and all fractional shares were rounded down to the nearest whole share with respect to outstanding shares of common stock. Any holders of common stock who would have otherwise received a fractional share of common stock pursuant to the Reverse Stock Split, received cash in lieu of the fractional share. All prior period share and per share amounts of the Company's common stock presented have been retroactively adjusted to reflect the 1-for-12 Reverse Stock Split, including reclassifying an amount equal to the reduction in par value of common stock to additional paid-in capital. |
Net Loss per Share | Net Loss per Share Basic net loss per share of common stock excludes dilution and is computed by dividing net loss by the weighted average number of shares of common stock outstanding during the period. Diluted net loss per share of common stock reflects the potential dilution that could occur if securities or other contracts to issue common stock were exercised or converted into common stock or resulted in the issuance of common stock that then shared in the earnings of the entity unless inclusion of such shares would be anti-dilutive. Diluted net loss per share is the same as basic net loss per share, since the effects of potentially dilutive securities are antidilutive given the net loss for each period presented. A reconciliation of the numerators and the denominators of the basic and diluted net loss per common share computations is as follows (in thousands, except for share and per share amounts): Three Months Ended March 31, 2024 2023 Numerator: Net loss $ ( 9,077 ) $ ( 18,950 ) Denominator: Weighted average common shares outstanding - basic and diluted 5,483,313 4,251,037 Net loss per share - basic and diluted $ ( 1.66 ) $ ( 4.46 ) Securities excluded from the computation of diluted net loss per share because including them would have been antidilutive are as follows: March 31, 2024 2023 Options to purchase common stock 1,026,696 876,272 Common stock subject to purchase under Employee Stock Purchase Plan 7,545 7,740 Unvested RSUs 103,752 143,110 Total 1,137,993 1,027,122 |
Summary of Significant Accoun_3
Summary of Significant Accounting Policies (Tables) | 3 Months Ended |
Mar. 31, 2024 | |
Accounting Policies [Abstract] | |
Schedule of Earnings Per Share, Basic and Diluted | A reconciliation of the numerators and the denominators of the basic and diluted net loss per common share computations is as follows (in thousands, except for share and per share amounts): Three Months Ended March 31, 2024 2023 Numerator: Net loss $ ( 9,077 ) $ ( 18,950 ) Denominator: Weighted average common shares outstanding - basic and diluted 5,483,313 4,251,037 Net loss per share - basic and diluted $ ( 1.66 ) $ ( 4.46 ) |
Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share | Securities excluded from the computation of diluted net loss per share because including them would have been antidilutive are as follows: March 31, 2024 2023 Options to purchase common stock 1,026,696 876,272 Common stock subject to purchase under Employee Stock Purchase Plan 7,545 7,740 Unvested RSUs 103,752 143,110 Total 1,137,993 1,027,122 |
Fair Value Measurements and I_2
Fair Value Measurements and Investments in Marketable Securities (Tables) | 3 Months Ended |
Mar. 31, 2024 | |
Investments, Debt and Equity Securities [Abstract] | |
Schedule of Investments in Marketable Securities | Investments in marketable securities consisted of the following (in thousands): March 31, 2024 Amortized Gross Gross Fair Value Cash equivalents Money market fund $ 18,110 $ — $ — $ 18,110 Total cash equivalents 18,110 — — 18,110 Short-term marketable securities U.S. and foreign corporate debt securities 17,764 12 — 17,776 U.S. treasury securities 60,471 20 ( 6 ) 60,485 U.S. and foreign commercial paper 15,958 11 ( 3 ) 15,966 Total short-term marketable securities 94,193 43 ( 9 ) 94,227 Total cash equivalents and marketable securities $ 112,303 $ 43 $ ( 9 ) $ 112,337 December 31, 2023 Amortized Gross Gross Fair Value Cash equivalents Money market fund $ 18,982 $ — $ — $ 18,982 Total cash equivalents 18,982 — — 18,982 Short-term marketable securities U.S. and foreign corporate debt securities 17,595 41 ( 3 ) 17,633 U.S. treasury securities 76,891 127 — 77,018 U.S. and foreign commercial paper 15,728 27 — 15,755 Total short-term marketable securities 110,214 195 ( 3 ) 110,406 Total cash equivalents and marketable securities $ 129,196 $ 195 $ ( 3 ) $ 129,388 There were no realized gains and losses for the three months ended March 31, 2024 and 2023 . |
Schedule of Fair Value of Financial Assets | The following tables present the fair value of the Company’s financial assets measured at fair value on a recurring basis (in thousands): March 31, 2024 Level 1 Level 2 Level 3 Fair Value Cash equivalents Money market fund $ 18,110 $ — $ — $ 18,110 Total cash equivalents 18,110 — — 18,110 Short-term marketable securities U.S. and foreign corporate debt securities — 17,776 — 17,776 U.S. treasury securities — 60,485 — 60,485 U.S. and foreign commercial paper — 15,966 — 15,966 Total short-term marketable securities — 94,227 — 94,227 Total assets measured at fair value $ 18,110 $ 94,227 $ — $ 112,337 December 31, 2023 Level 1 Level 2 Level 3 Fair Value Cash equivalents Money market fund $ 18,982 $ — $ — $ 18,982 Total cash equivalents 18,982 — — 18,982 Short-term marketable securities U.S. and foreign corporate debt securities — 17,633 — 17,633 U.S. treasury securities — 77,018 — 77,018 U.S. and foreign commercial paper — 15,755 — 15,755 Total short-term marketable securities — 110,406 — 110,406 Total assets measured at fair value $ 18,982 $ 110,406 $ — $ 129,388 |
Other Accrued Expenses (Tables)
Other Accrued Expenses (Tables) | 3 Months Ended |
Mar. 31, 2024 | |
Payables and Accruals [Abstract] | |
Schedule of Other Accrued Expenses | Other accrued expenses consist of the following (in thousands): March 31, December 31, Accrued expenses: Accrued compensation $ 1,727 $ 5,484 Accrued professional fees and other 324 260 Total accrued expenses $ 2,051 $ 5,744 |
Stock-Based Compensation (Table
Stock-Based Compensation (Tables) | 3 Months Ended |
Mar. 31, 2024 | |
Share-Based Payment Arrangement [Abstract] | |
Schedule of Recognized Stock-Based Compensation Expense | The following table summarizes the components of total stock-based compensation expense included in the condensed consolidated statements of operations and comprehensive loss (in thousands): Three Months Ended March 31, 2024 2023 Research and development $ 354 $ 910 General and administrative 385 925 Total stock-based compensation expense $ 739 $ 1,835 |
Summary of Assumptions Used to Estimate Fair Values of Stock Options Grants | The fair value of stock options granted during the periods indicated was estimated using the Black-Scholes option pricing model, based on the following assumptions: Three Months Ended March 31, 2024 2023 Exercise price $ 13.30 $ 10.68 - $ 18.36 Expected volatility 80.4 % - 86.9 % 77.5 % - 82.8 % Risk-free rate 4.16 % 3.59 % - 4.00 % Expected term (years) 5.5 - 7.0 5.5 - 7.0 Expected dividend yield 0 % 0 % |
Collaboration Agreements (Table
Collaboration Agreements (Tables) | 3 Months Ended |
Mar. 31, 2024 | |
Collaboration Agreement [Abstract] | |
Schedule of Changes in Contract Liabilities | The following table presents changes in the Company’s contract liabilities (in thousands): Balance at Additions Deductions Balance at Three Months Ended March 31, 2024 Contract liabilities: Deferred revenue $ 86,294 $ — $ ( 5,785 ) $ 80,509 |
Schedule of Collaboration Revenue Recognized with the Period | Three Months Ended March 31, 2024 2023 Collaboration revenue recognized in the period from Amounts included in deferred revenue at the beginning of the period $ 5,785 $ — Performance obligations satisfied in previous period $ — $ — |
Nature of Business - Additional
Nature of Business - Additional Information (Details) | 3 Months Ended |
Mar. 31, 2024 Segment Product | |
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items] | |
FDA approved products (in products) | Product | 0 |
Operating segments (in segments) | Segment | 1 |
Summary of Significant Accoun_4
Summary of Significant Accounting Policies - Schedule of Earnings Per Share, Basic and Diluted (Details) - USD ($) $ / shares in Units, $ in Thousands | 3 Months Ended | |
Mar. 31, 2024 | Mar. 31, 2023 | |
Numerator: | ||
Net loss | $ (9,077) | $ (18,950) |
Denominator: | ||
Weighted average common shares outstanding - basic | 5,483,313 | 4,251,037 |
Weighted average common shares outstanding - diluted | 5,483,313 | 4,251,037 |
Net loss per share - basic | $ (1.66) | $ (4.46) |
Net loss per share - diluted | $ (1.66) | $ (4.46) |
Summary of Significant Accoun_5
Summary of Significant Accounting Policies - Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share (Details) - shares | 3 Months Ended | |
Mar. 31, 2024 | Mar. 31, 2023 | |
Antidilutive Securities Excluded from Computation of Earnings Per Share | ||
Antidilutive securities excluded from computation of loss per share | 1,137,993 | 1,027,122 |
Options to purchase common stock | ||
Antidilutive Securities Excluded from Computation of Earnings Per Share | ||
Antidilutive securities excluded from computation of loss per share | 1,026,696 | 876,272 |
Common stock subject to purchase under Employee Stock Purchase Plan | ||
Antidilutive Securities Excluded from Computation of Earnings Per Share | ||
Antidilutive securities excluded from computation of loss per share | 7,545 | 7,740 |
Unvested RSUs | ||
Antidilutive Securities Excluded from Computation of Earnings Per Share | ||
Antidilutive securities excluded from computation of loss per share | 103,752 | 143,110 |
Summary of Significant Accoun_6
Summary of Significant Accounting Policies - Additional Information (Details) | 1 Months Ended | 3 Months Ended | ||||
Feb. 09, 2024 shares | Feb. 08, 2024 shares | Jan. 31, 2024 | Mar. 31, 2024 shares | Dec. 31, 2023 shares | Sep. 30, 2023 $ / shares | |
Significant Accounting Policies [Line Items] | ||||||
Reverse stock split description | In January 2024, the Company's stockholders approved a reverse stock split of its common stock at a range of ratios between 1-for-7 to 1-for-17, and the Company's board of directors approved the implementation of the reverse stock split at a ratio of 1-for-12 (the Reverse Stock Split). The Reverse Stock Split was effective as of February 9, 2024 and the Company regained compliance with the minimum bid price requirement in February 2024. | |||||
Reverse stock split ratio | 0.0833 | 0.0833 | ||||
Common stock, shares outstanding | 5,482,752 | 5,482,752 | ||||
Common stock shares outstanding due to reverse stock split | 5,500,000 | 65,800,000 | ||||
Number of shares issued in connection with reverse stock split | 0 | |||||
Maximum | ||||||
Significant Accounting Policies [Line Items] | ||||||
Reverse stock split ratio | 0.0588 | |||||
Closing bid price of stock | $ / shares | $ 1 | |||||
Minimum | ||||||
Significant Accounting Policies [Line Items] | ||||||
Reverse stock split ratio | 0.1429 | |||||
Closing bid price of stock | $ / shares | $ 1 |
Related Party - Additional Info
Related Party - Additional Information (Details) $ in Thousands | 1 Months Ended | 3 Months Ended | |
Oct. 31, 2023 USD ($) Director | Mar. 31, 2024 USD ($) | Mar. 31, 2023 USD ($) | |
Related Party Transaction [Line Items] | |||
Revenue recognized | $ 5,785 | $ 0 | |
Gilead Sciences, Inc. | Gilead Equity Agreements | |||
Related Party Transaction [Line Items] | |||
Number of directors, right to designate in company board | Director | 2 | ||
Gilead Sciences, Inc. | Gilead Equity Agreements | Common Stock | |||
Related Party Transaction [Line Items] | |||
Percentage of outstanding voting of common stock held | 0.199 | ||
Maximum percentage of then-outstanding voting capital stock | 29.90% | ||
Gilead Sciences, Inc. | Gillead Collaboration Agreement | |||
Related Party Transaction [Line Items] | |||
Proceeds received in collaboration agreement | $ 100,000 | ||
Revenue recognized | $ 5,800 |
Fair Value Measurements and I_3
Fair Value Measurements and Investments in Marketable Securities - Schedule of Investments in Marketable Securities (Details) - USD ($) $ in Thousands | Mar. 31, 2024 | Dec. 31, 2023 |
Investments in marketable securities: | ||
Amortized Cost | $ 18,110 | $ 18,982 |
Investment, Type [Extensible Enumeration] | Cash Equivalents [Member] | Cash Equivalents [Member] |
Gross Unrealized Gain | $ 0 | $ 0 |
Gross Unrealized Loss | 0 | 0 |
Fair Value | 18,110 | 18,982 |
Amortized Cost, Short-term marketable securities | 94,193 | 110,214 |
Gross Unrealized Gain, Short-term marketable securities | 43 | 195 |
Gross Unrealized Loss, Short-term marketable securities | (9) | (3) |
Fair Value, Short-term marketable securities | 94,227 | 110,406 |
Amortized Cost | 112,303 | 129,196 |
Gross Unrealized Gain | 43 | 195 |
Gross Unrealized Loss | (9) | (3) |
Fair Value | 112,337 | 129,388 |
Money market fund | ||
Investments in marketable securities: | ||
Amortized Cost | 18,110 | 18,982 |
Gross Unrealized Gain | 0 | 0 |
Gross Unrealized Loss | 0 | 0 |
Fair Value | 18,110 | 18,982 |
U.S and foreign corporate debt securities | ||
Investments in marketable securities: | ||
Amortized Cost, Short-term marketable securities | 17,764 | 17,595 |
Gross Unrealized Gain, Short-term marketable securities | 12 | 41 |
Gross Unrealized Loss, Short-term marketable securities | 0 | (3) |
Fair Value, Short-term marketable securities | 17,776 | 17,633 |
U.S. treasury securities | ||
Investments in marketable securities: | ||
Amortized Cost, Short-term marketable securities | 60,471 | 76,891 |
Gross Unrealized Gain, Short-term marketable securities | 20 | 127 |
Gross Unrealized Loss, Short-term marketable securities | (6) | 0 |
Fair Value, Short-term marketable securities | 60,485 | 77,018 |
U.S. and foreign commercial paper | ||
Investments in marketable securities: | ||
Amortized Cost, Short-term marketable securities | 15,958 | 15,728 |
Gross Unrealized Gain, Short-term marketable securities | 11 | 27 |
Gross Unrealized Loss, Short-term marketable securities | (3) | 0 |
Fair Value, Short-term marketable securities | $ 15,966 | $ 15,755 |
Fair Value Measurements and I_4
Fair Value Measurements and Investments in Marketable Securities - Additional Information (Details) - USD ($) | 3 Months Ended | ||
Mar. 31, 2024 | Mar. 31, 2023 | Dec. 31, 2023 | |
Investments in marketable securities: | |||
Realized gains and losses | $ 0 | $ 0 | |
Accrued interest receivable | 300,000 | $ 300,000 | |
Fair value assets transfers between level 1, level 2 or level 3 | $ 0 | $ 0 |
Fair Value Measurements and I_5
Fair Value Measurements and Investments in Marketable Securities - Schedule of Fair Value of Financial Assets (Details) - USD ($) $ in Thousands | Mar. 31, 2024 | Dec. 31, 2023 |
Cash equivalents | ||
Cash equivalents | $ 18,110 | $ 18,982 |
Short-term marketable securities | ||
Short-term marketable securities | 94,227 | 110,406 |
U.S. treasury securities | ||
Short-term marketable securities | ||
Short-term marketable securities | 60,485 | 77,018 |
U.S and foreign corporate debt securities | ||
Short-term marketable securities | ||
Short-term marketable securities | 17,776 | 17,633 |
Money market fund | ||
Cash equivalents | ||
Cash equivalents | 18,110 | 18,982 |
Recurring | ||
Cash equivalents | ||
Cash equivalents | 18,110 | 18,982 |
Short-term marketable securities | ||
Short-term marketable securities | 94,227 | 110,406 |
Long-term marketable securities | ||
Total assets measured at fair value | 112,337 | 129,388 |
Recurring | U.S and foreign corporate debt securities | ||
Short-term marketable securities | ||
Short-term marketable securities | 17,776 | 17,633 |
Recurring | U.S. treasury securities | ||
Short-term marketable securities | ||
Short-term marketable securities | 60,485 | 77,018 |
Recurring | U.S. and foreign commercial paper | ||
Short-term marketable securities | ||
Short-term marketable securities | 15,966 | 15,755 |
Recurring | Money market fund | ||
Cash equivalents | ||
Cash equivalents | 18,110 | 18,982 |
Recurring | Level 1 | ||
Cash equivalents | ||
Cash equivalents | 18,110 | 18,982 |
Short-term marketable securities | ||
Short-term marketable securities | 0 | 0 |
Long-term marketable securities | ||
Total assets measured at fair value | 18,110 | 18,982 |
Recurring | Level 1 | U.S and foreign corporate debt securities | ||
Short-term marketable securities | ||
Short-term marketable securities | 0 | 0 |
Recurring | Level 1 | U.S. treasury securities | ||
Short-term marketable securities | ||
Short-term marketable securities | 0 | 0 |
Recurring | Level 1 | U.S. and foreign commercial paper | ||
Short-term marketable securities | ||
Short-term marketable securities | 0 | 0 |
Recurring | Level 1 | Money market fund | ||
Cash equivalents | ||
Cash equivalents | 18,110 | 18,982 |
Recurring | Level 2 | ||
Cash equivalents | ||
Cash equivalents | 0 | 0 |
Short-term marketable securities | ||
Short-term marketable securities | 94,227 | 110,406 |
Long-term marketable securities | ||
Total assets measured at fair value | 94,227 | 110,406 |
Recurring | Level 2 | U.S and foreign corporate debt securities | ||
Short-term marketable securities | ||
Short-term marketable securities | 17,776 | 17,633 |
Recurring | Level 2 | U.S. treasury securities | ||
Short-term marketable securities | ||
Short-term marketable securities | 60,485 | 77,018 |
Recurring | Level 2 | U.S. and foreign commercial paper | ||
Short-term marketable securities | ||
Short-term marketable securities | 15,966 | 15,755 |
Recurring | Level 2 | Money market fund | ||
Cash equivalents | ||
Cash equivalents | 0 | 0 |
Recurring | Level 3 | ||
Cash equivalents | ||
Cash equivalents | 0 | 0 |
Short-term marketable securities | ||
Short-term marketable securities | 0 | 0 |
Long-term marketable securities | ||
Total assets measured at fair value | 0 | 0 |
Recurring | Level 3 | U.S and foreign corporate debt securities | ||
Short-term marketable securities | ||
Short-term marketable securities | 0 | 0 |
Recurring | Level 3 | U.S. treasury securities | ||
Short-term marketable securities | ||
Short-term marketable securities | 0 | 0 |
Recurring | Level 3 | U.S. and foreign commercial paper | ||
Short-term marketable securities | ||
Short-term marketable securities | 0 | 0 |
Recurring | Level 3 | Money market fund | ||
Cash equivalents | ||
Cash equivalents | $ 0 | $ 0 |
Other Accrued Expenses - Schedu
Other Accrued Expenses - Schedule of Other Accrued Expenses (Details) - USD ($) $ in Thousands | Mar. 31, 2024 | Dec. 31, 2023 |
Accrued expenses: | ||
Accrued compensation | $ 1,727 | $ 5,484 |
Accrued professional fees and other | 324 | 260 |
Total accrued expenses | $ 2,051 | $ 5,744 |
Sale of Common Stock - Addition
Sale of Common Stock - Additional Information (Details) - 2020 At the Market Offerings - USD ($) $ in Millions | 3 Months Ended | ||
Mar. 31, 2024 | Mar. 31, 2023 | Aug. 31, 2020 | |
Subsidiary Sale Of Stock [Line Items] | |||
Initial public offering value of shares authorized | $ 100 | ||
Number of shares sold | 0 | 254,203 | |
Net proceeds from the issuance of common stock through equity plans | $ 4.5 |
Stock-Based Compensation - Sche
Stock-Based Compensation - Schedule of Recognized Stock-Based Compensation Expense (Details) - USD ($) $ in Thousands | 3 Months Ended | |
Mar. 31, 2024 | Mar. 31, 2023 | |
Compensation expense: | ||
Stock-based compensation expense | $ 739 | $ 1,835 |
Research and Development | ||
Compensation expense: | ||
Stock-based compensation expense | 354 | 910 |
General and Administrative | ||
Compensation expense: | ||
Stock-based compensation expense | $ 385 | $ 925 |
Stock-Based Compensation - Addi
Stock-Based Compensation - Additional Information (Details) $ in Millions | 3 Months Ended |
Mar. 31, 2024 USD ($) | |
Share-Based Payment Arrangement [Abstract] | |
Unrecognized stock-based compensation expense | $ 4.2 |
Unrecognized stock-based compensation expense expected to be recognized, term | 1 year 10 months 24 days |
Stock-Based Compensation - Summ
Stock-Based Compensation - Summary of Assumptions Used to Estimate Fair Values of Stock Options Grants (Details) - $ / shares | 3 Months Ended | |
Mar. 31, 2024 | Mar. 31, 2023 | |
Share-based Compensation Arrangement by Share-based Payment Award | ||
Exercise price | $ 13.3 | |
Risk-free rate | 4.16% | |
Expected dividend yield | 0% | 0% |
Minimum | ||
Share-based Compensation Arrangement by Share-based Payment Award | ||
Exercise price | $ 10.68 | |
Expected volatility | 80.40% | 77.50% |
Risk-free rate | 3.59% | |
Expected term (years) | 5 years 6 months | 5 years 6 months |
Maximum | ||
Share-based Compensation Arrangement by Share-based Payment Award | ||
Exercise price | $ 18.36 | |
Expected volatility | 86.90% | 82.80% |
Risk-free rate | 4% | |
Expected term (years) | 7 years | 7 years |
Collaboration Agreements - Addi
Collaboration Agreements - Additional Information (Details) | 1 Months Ended | 3 Months Ended | ||
Oct. 31, 2023 USD ($) Program Timepoint | Mar. 31, 2024 USD ($) | Mar. 31, 2023 USD ($) | Dec. 31, 2023 USD ($) | |
Research And Development Arrangement Contract To Perform For Others [Line Items] | ||||
Research and development expense | $ 11,879,000 | $ 14,547,000 | ||
Collaboration revenue | 5,785,000 | 0 | ||
Contract liability/deferred revenue | 80,509,000 | $ 86,294,000 | ||
Deferred revenue - short-term | 32,771,000 | 30,915,000 | ||
Deferred revenue - long-term | 47,738,000 | $ 55,379,000 | ||
Arbutus Biopharma Agreement | ||||
Research And Development Arrangement Contract To Perform For Others [Line Items] | ||||
Research and development expense | 0 | $ 600,000 | ||
Option, License and Collaboration Agreement | Gilead Sciences, Inc. | ||||
Research And Development Arrangement Contract To Perform For Others [Line Items] | ||||
Collaboration revenue | 5,800,000 | |||
Proceeds received in collaboration agreement | $ 100,000,000 | |||
Collaboration term | 12 years | |||
Number of timepoints of program | Timepoint | 2 | |||
Percentage cover of research and development costs | 40% | |||
Percentage share of profits and operating loss for products | 40% | |||
Number of fellow-contributed programs | Program | 2 | |||
Contract liability/deferred revenue | $ 90,700,000 | |||
Initial non-cancellable term | 3 years | |||
Deferred revenue - short-term | 32,800,000 | |||
Deferred revenue - long-term | 47,700,000 | |||
Reimbursable expenses | $ 200,000 | |||
Option, License and Collaboration Agreement | Minimum | Gilead Sciences, Inc. | ||||
Research And Development Arrangement Contract To Perform For Others [Line Items] | ||||
Threshold payment of opt-in fee | $ 45,000,000 | |||
Option, License and Collaboration Agreement | Maximum | Gilead Sciences, Inc. | ||||
Research And Development Arrangement Contract To Perform For Others [Line Items] | ||||
Threshold payment of opt-in fee | 125,000,000 | |||
Option, License and Collaboration Agreement | Regulatory and Commercial Milestones | Maximum | Gilead Sciences, Inc. | ||||
Research And Development Arrangement Contract To Perform For Others [Line Items] | ||||
Potential milestone payments | 330,000,000 | |||
Seventh Year of Collaboration Agreement | Gilead Sciences, Inc. | ||||
Research And Development Arrangement Contract To Perform For Others [Line Items] | ||||
Potential proceeds from collaboration extension fees | $ 75,000,000 |
Collaboration Agreements - Sche
Collaboration Agreements - Schedule of Changes in Contract Liabilities (Details) $ in Thousands | 3 Months Ended |
Mar. 31, 2024 USD ($) | |
Collaboration Agreement [Abstract] | |
Balance at Beginning of Period | $ 86,294 |
Additions | 0 |
Deductions | (5,785) |
Balance at End of Period | $ 80,509 |
Collaboration Agreements - Sc_2
Collaboration Agreements - Schedule of Collaboration Revenue Recognized with the Period (Details) - USD ($) $ in Thousands | 3 Months Ended | |
Mar. 31, 2024 | Mar. 31, 2023 | |
Collaboration revenue recognized in the period from | ||
Amounts included in deferred revenue at the beginning of the period | $ 5,785 | $ 0 |
Performance obligations satisfied in previous period | $ 0 | $ 0 |
Milestones and Research Agree_2
Milestones and Research Agreements - Additional Information (Details) - USD ($) $ in Millions | 3 Months Ended | |
Mar. 31, 2024 | Mar. 31, 2023 | |
Milestones And Research Agreements [Abstract] | ||
Potential milestone payment | $ 0.8 | |
Milestone payment, diligence maintenance fees | $ 0.1 | $ 0.1 |
Subsequent Event - Additional I
Subsequent Event - Additional Information (Details) - Gilead Sciences, Inc. $ in Millions | 1 Months Ended |
Oct. 31, 2023 USD ($) Program Timepoint | |
Option, License and Collaboration Agreement | |
Subsequent Event [Line Items] | |
Collaboration term | 12 years |
Proceeds received in collaboration agreement | $ 100 |
Number of timepoints of program | Timepoint | 2 |
Percentage cover of research and development costs | 40% |
Percentage share of profits and operating loss for products | 40% |
Number of fellow-contributed programs | Program | 2 |
Option, License and Collaboration Agreement | Minimum | |
Subsequent Event [Line Items] | |
Threshold payment of opt-in fee | $ 45 |
Option, License and Collaboration Agreement | Maximum | |
Subsequent Event [Line Items] | |
Threshold payment of opt-in fee | 125 |
Option, License and Collaboration Agreement | Regulatory and Commercial Milestones | Maximum | |
Subsequent Event [Line Items] | |
Potential milestone payments | 330 |
Seventh Year of Collaboration Agreement | |
Subsequent Event [Line Items] | |
Potential proceeds from collaboration extension fees | $ 75 |