Mintz advised the underwriters in connection with Assembly Biosciences, Inc.’s underwritten offering of an aggregate of 5,591,840 shares of common stock and pre-funded warrants to purchase up to 1,040,820 shares of common stock, together with accompanying Class A and Class B warrants to purchase up to an aggregate of 6,632,660 shares of common stock at a combined price per share of common stock and accompanying Class A warrant and Class B warrant of $19.60 and a combined price per pre-funded warrant and accompanying Class A warrant and Class B warrant of $19.599. Each pre-funded warrant had a nominal exercise price of $0.001 per share of common stock and will be immediately exercisable. Each accompanying Class A warrant had an exercise price of $21.60 per share of common stock, and will be immediately exercisable and will expire on the earlier of (i) five years from the date of issuance (August 11, 2030) and (ii) the date that is 30 days after the public announcement that Assembly Biosciences has completed enrollment (of at least 200 patients total) for its Phase 2 clinical study evaluating ABI-5366 vs. valacyclovir. Each accompanying Class B warrant will have an exercise price of $21.60 per share of common stock, will be exercisable on or after November 15, 2026 and will expire on December 31, 2026, provided that each Class B warrant will automatically terminate in full and be extinguished and shall no longer be exercisable in the event that the Assembly Biosciences publicly announces prior to November 15, 2026 that it has received at least $75.0 million in the aggregate of non-dilutive capital in connection with a collaboration agreement.

Guggenheim Securities acted as lead book-running manager for the offering. Mizuho also acted as a book-running manager for the offering.

In addition to the underwritten offering, Assembly Biosciences closed a private placement to Gilead Sciences, Inc. of 2,295,920 shares of common stock and accompanying Class A warrants and Class B warrants to purchase up to an aggregate of 2,295,920 shares of common stock at a price per share, together with accompanying warrants, equal to the offering price of the underwritten offering described above.

The Mintz capital markets team included William Hicks, John Rudy, Alok Choksi, Gianna Nappi, Hannah Karraker, Gretchen Goyette, and Nicole Gaston. Joanne Hawana provided regulatory advice; Edmund Koundakjian and Evelyne Guillouet-Walters provided intellectual property advice; and Ari Feder provided tax advice. Members of the Mintz team are based in the Boston, New York, Washington, DC, San Francisco, and San Diego offices.