Assembly Bioscie SEC Filings

Commodore Capital and affiliated persons disclosed a 1,615,981-share position in Assembly Biosciences, representing 9.9% of outstanding common stock. The reported holdings comprise 1,000,000 issued shares plus 615,981 shares issuable upon exercise of a pre-funded warrant, subject to a 9.99% beneficial ownership limitation. The filing identifies Commodore Capital LP, Commodore Capital Master LP and two individual managing partners as filers and states the Firm acts as investment manager with shared voting and dispositive power over the reported shares. Certain additional warrants and underlying shares are excluded from the reported aggregate because they are subject to the same ownership limitation.

Alexander Schornstein amended a prior Schedule 13D to report his beneficial ownership in Assembly Biosciences, Inc. He beneficially owns 728,113 shares of common stock, representing 4.68% of the outstanding class based on 15,560,009 shares reported in the registraton statement. The total includes 607,089 shares held directly by Mr. Schornstein and 92,024 shares held by Camino Capital GmbH, of which he is the sole beneficial owner with sole voting and dispositive power. The filing states Mr. Schornstein no longer owns at least 5% of the company and therefore is no longer required to file further Schedule 13D amendments. The statement affirms these holdings and the classification of the filing under Rule 13d-1.

Gilead Sciences purchased a significant stake in Assembly Biosciences and acquired related warrants. Under a Securities Purchase Agreement dated August 8, 2025, Gilead paid a combined price of $19.60 per share to buy 2,295,920 shares of Assembly common stock plus accompanying warrants, with the transaction closing on August 11, 2025 for approximately $45 million funded from Gilead's cash resources. After the purchase, Gilead beneficially owns 4,505,391 shares, representing 29.0% of the outstanding common stock based on 15,560,009 shares outstanding following the issuer's public offering.

The purchase included a Series A Warrant exercisable immediately at an exercise price of $21.60 (expiring August 11, 2030 or earlier upon a public announcement of a specified Phase 2 enrollment milestone) and a Series B Warrant exercisable on or after November 15, 2026 at $21.60 (expiring December 31, 2026 and subject to termination if the issuer receives at least $75 million of specified non-dilutive capital before November 15, 2026). Each warrant is subject to a 19.99% beneficial ownership limitation, and 2,475,420 underlying shares from warrants are not deemed beneficially owned due to that limitation.

Assembly Biosciences completed a registered underwritten offering and a concurrent private placement to raise capital. The registered offering included 5,591,840 shares of common stock at an offering price of $19.60 per share plus accompanying Class A and Class B warrants, and pre-funded warrants to purchase up to 1,040,820 shares at $19.599 per pre-funded warrant. The closing of the Offering occurred on August 11, 2025, and the aggregate net proceeds to the Company from the Offering were approximately $122.0 million, after estimated offering expenses.

Concurrently, the Company sold 2,295,920 shares and accompanying warrants to Gilead Sciences in a private placement, with aggregate net proceeds of approximately $45.0 million. The Company intends to use the net proceeds from the Offering and the Private Placement for general corporate purposes. Key warrant terms disclosed include a $21.60 exercise price for the Warrants, Class A Warrants becoming immediately exercisable and expiring no later than August 11, 2030, Class B Warrants exercisable after November 15, 2026 and expiring December 31, 2026, and Pre-Funded Warrants with an initial exercise price of $0.001 and no termination date.

Assembly Biosciences is selling 5,591,840 shares of common stock (and/or pre-funded warrants for up to 1,040,820 shares) together with Class A and Class B warrants to purchase up to an aggregate of 6,632,660 shares, at a combined offering price of $19.60 per share (each share sold with one-half of a Class A warrant and one-half of a Class B warrant). Concurrently the company expects to sell 2,295,920 private placement shares and warrants to Gilead for approximately $45.0 million. Together with the public offering, net proceeds are expected to be approximately $167.2 million, which the company states should be sufficient to fund planned operations for at least the next twelve months and to address previously disclosed substantial doubt about its ability to continue as a going concern.

Clinical updates accompany the financing: interim Phase 1b ABI-5366 data showed a 94% reduction in HSV-2 shedding and a 94% reduction in days with genital lesions at a 350 mg weekly dose, supporting weekly or potentially monthly oral dosing; Phase 1a ABI-6250 data showed a mean oral half-life of four days and biomarker evidence of target engagement, with some self-limited ALT elevations at the highest single dose. Investors should note immediate dilution to new investors of $10.09 per share, that the warrants and pre-funded warrants will not be listed and likely lack liquidity, and that Class A and B warrants have $21.60 exercise prices and specific expiration/termination conditions.

Assembly Biosciences is offering shares of common stock and/or pre-funded warrants, each sold together with a Class A warrant and a Class B warrant, with a concurrent private placement to Gilead. The prospectus discloses that the closing of the public offering and the Gilead private placement are contingent on each other and that net proceeds from the combined financings are expected to be sufficient to fund operations for at least the next twelve months, addressing previously disclosed substantial doubt about the company’s ability to continue as a going concern.

The filing highlights clinical progress: interim Phase 1b data for ABI-5366 showed a 94% reduction in HSV-2 shedding versus placebo (p<0.01) at a 350 mg weekly dose, a 94% reduction in days with genital lesions (p<0.01), and a 98% reduction in high viral‑load samples (>10^4 copies/mL, p<0.05); ABI-5366 was well tolerated at doses up to 350 mg weekly and supports once-weekly or potentially once‑monthly dosing. Interim Phase 1a data for ABI-6250 showed a mean half-life of four days and dose-dependent bile acid elevations; a grade 2 ALT occurred at the highest single dose and grade 1 elevations occurred infrequently, all self-limited and without bilirubin elevations.

Assembly Biosciences (ASMB) filed an 8-K reporting interim Phase 1b results for its long-acting HSV helicase-primase inhibitor ABI-5366.

The 350 mg once-weekly oral dose achieved a 94% reduction in HSV-2 viral shedding versus placebo (p<0.01) over 29 days, exceeding the study’s 80-85% target. Secondary endpoints also improved: 94% lower genital-lesion rate and 98% reduction in high-viral-load samples (p<0.05). The drug was well-tolerated at doses up to 350 mg weekly, and its pharmacokinetic profile supports both once-weekly and potential once-monthly dosing.

With these data, Assembly plans to move directly into Phase 2 preparations while finishing the Phase 1b trial’s monthly-dosing cohort. Chronic toxicology studies are complete and expected to support longer-term dosing in Phase 2.

What this filing says, in plain language

Assembly Biosciences is an early-stage biotech working on several antiviral drug programs. As of June 30, 2025, it held about $24.0 million in cash and $51.0 million in marketable securities (approximately $75.0 million total). Management says that amount is not sufficient to fund operations beyond one year, and the company has substantial doubt about its ability to continue as a going concern unless it secures more funding. The company recognized collaboration revenue from Gilead of $9.6 million this quarter ($19.0 million for the six months) and has deferred revenue from that collaboration of about $53.96 million, which supports near-term work. The company reported a net loss of $10.2 million this quarter ($19.0 million six months) and used $40.2 million in cash for operations in the first half of 2025. Clinically, Assembly reported positive early human data for two long-acting herpes drug candidates (5366 and 1179), topline antiviral results for its HBV candidate (4334), and ongoing Phase 1 work for its HDV entry inhibitor (6250). These results show scientific progress but the company has no approved products and needs additional financing to continue development.