Gilead, Merck sign pact to develop, commercialise long-acting HIV treatment combinations

Gilead Sciences and Merck, known as MSD outside the US and Canada, announced that they have entered into an agreement to co-develop and co-commercialise long-acting treatments in HIV that combine Gilead’s investigational capsid inhibitor, lenacapavir, and Merck’s investigational nucleoside reverse transcriptase translocation inhibitor, islatravir, into a two-drug regimen with the potential to provide new, meaningful treatment options for people living with HIV.

Islatravir and lenacapavir are both potentially first-in-class medicines in late-stage clinical trials, with significant clinical data generated to date. Both medicines have long half-lives and have demonstrated activity at low dosages in clinical studies, which support development as an investigational combination regimen with long-acting formulations, both oral and injectable.

The first clinical studies of the oral combination are expected to begin in the second half of 2021. Under the terms of the agreement, Gilead and Merck will work as partners, sharing operational responsibilities, as well as development, commercialisation and marketing costs, and any future revenues.

While daily, single-tablet regimens are available for people living with HIV, options that would allow for less frequent, oral dosing or infrequent injections rather than daily dosing have the potential to address preference considerations, as well as issues associated with adherence and privacy.

As the field of HIV treatment evolves, long-acting therapies may provide additional options for people living with HIV and their physicians that will help continue to put the needs of individuals at the center of their own care.

Kenneth C Frazier, Chairman and CEO, Merck said, “This collaboration with Gilead brings together two companies dedicated to the fight against HIV to develop potential new long-acting treatment options, and is an important step forward in our strategy to harness the full potential of islatravir for the treatment of HIV.”

Daniel O’Day, Chairman and CEO, Gilead Sciences said, “Our work in HIV over the past decades has been shaped by listening to people living with HIV and the physicians who treat them. Now we are taking the same approach with long-acting therapies, combining the most advanced science from both companies to accelerate progress.”

Lenacapavir and islatravir, alone and in combination, are investigational and not approved anywhere globally. Their safety and efficacy have not yet been established.

Beyond the potential combinations of lenacapavir and islatravir, Gilead will have the option to license certain of Merck’s investigational oral integrase inhibitors to develop in combination with lenacapavir. Reciprocally, Merck will have the option to license certain of Gilead’s investigational oral integrase inhibitors to develop in combination with islatravir. Each company may exercise its option for an investigational oral integrase inhibitor of the other company following completion of the first Phase 1 clinical trial of that integrase inhibitor. Upon exercise of an option, the companies will split development cost and revenues, unless the non-exercising company decides to opt-out. Both companies currently have oral once-weekly integrase inhibitors in preclinical development.

Cowen & Company LLC is acting as financial advisor to Gilead. Hogan Lovells and White & Case, LLP are serving as legal counsel to Gilead. Morgan, Lewis & Bockius and Gibson Dunn are serving as legal counsel to Merck.