Gilead Enters Long-Term Partnership With Assembly Biosciences to Address Hepatitis, Herpes

This morning Gilead Sciences and Assembly Biosciences announced they had entered into a 12-year partnership to advance the research and development of novel antiviral therapies, with an initial focus in Assembly Bio’s established areas of herpesviruses (HSV), hepatitis B virus (HBV) and hepatitis D virus (HDV).

Assembly is a biotechnology company that creates antiviral therapeutics. “We are thrilled to partner with Gilead to address significant unmet medical needs in herpesviruses, viral hepatitis and beyond,” Jason Okazaki, chief executive officer and president of Assembly Bio, said in a statement. “With Gilead’s established success in developing and commercializing antiviral medicines and Assembly Bio’s advanced virology research capabilities, we believe the shared expertise and promising investigational therapies that both organizations contribute to this collaboration have the potential to deliver significant advances to patients.”

According to the press statement, Gilead may opt-in to obtain exclusive rights for each of Assembly Bio’s current and future programs, including 2 preclinical programs targeting HSV and transplant-associated herpesviruses that Gilead is licensing to Assembly Bio, upon payment of an opt-in fee of at least $45 million per program after clinical proof-of-concept is achieved. If Gilead opts-in to any current or future program under the collaboration, Assembly Bio is eligible to receive up to $330 million per program in potential regulatory and commercial milestones, in addition to royalties ranging from the high single digits to high teens.

During the term of the collaboration, Assembly Bio will also be eligible to receive 3 separate $75 million collaboration extension payments at prespecified timepoints during the collaboration term to help fund future research and development.

Under the terms of the agreement, Assembly Bio will receive $100 million, consisting of an $84.8 million upfront payment and a $15.2 million equity investment from Gilead. The company’s initial equity investment at a premium represents 19.9 percent of the outstanding voting stock of Assembly Bio as of the date of closing. In addition, subject to certain conditions, Gilead has agreed to purchase up to 29.9 percent of Assembly Bio’s outstanding voting stock at a premium.

“Advancing the next wave of innovation in virology remains a core focus for Gilead as we seek to address the unmet needs of people affected by serious viral infections around the world,” said Tomas Cihlar, Senior Vice President of Virology Research, Gilead.