By Colin Kellaher


Gilead Sciences is taking a significant stake in smaller biotechnology peer Assembly Biosciences as part of a 12-year partnership aimed at advancing the research and development of novel antiviral therapies.

Gilead and Assembly on Tuesday said the work will initially focus on Assembly's established areas of herpesviruses, hepatitis B virus and hepatitis D virus.

As part of the agreement, Assembly will receive an upfront payment of $100 million, including a $15 million investment by Gilead, which is buying nearly 13.1 million shares at $1.16 apiece, a roughly 60% premium to Monday's closing price of 72.6 cents for the South San Francisco, Calif., company.

The companies said Gilead's initial investment represents 19.9% of Assembly's voting stock, adding that Gilead has agreed to buy up to 29.9% of the South San Francisco, Calif., company's voting stock, subject to certain conditions.

The companies said Gilead, based in Foster City, Calif., can opt-in to obtain exclusive rights for each of Assembly's current and future programs upon payment of an opt-in fee of at least $45 million per program, with Assembly eligible to receive up to $330 million per program in potential regulatory and commercial milestones, along with royalties on sales.

Trading in shares of Assembly was halted premarket on Tuesday.


Write to Colin Kellaher at colin.kellaher@wsj.com


(END) Dow Jones Newswires

10-17-23 0736ET