Gilead and Merck to collaborate on long-acting HIV treatments

Gilead Sciences and Merck (MSD outside the US and Canada) have entered into an agreement to co-develop and co-commercialise long-acting treatments for HIV. These treatments will combine Gilead’s investigational capsid inhibitor, lenacapavir, and Merck’s investigational nucleoside reverse transcriptase translocation inhibitor, islatravir, into a two-drug regimen.

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, the companies will share operational responsibilities, as well as development, commercialisation and marketing costs, and any future revenues.

“At Merck, we are resolute in our commitment to advancing the care of people living with HIV as part of our mission to save and improve lives,” said Kenneth Frazier, Chairman and Chief Executive Officer, Merck. “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.”

“Through this agreement with Merck, Gilead is reinforcing its long-term role in transforming HIV care,” stated Daniel O’Day, Chairman and Chief Executive Officer, Gilead Sciences. “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.”

Terms of the collaboration

Under the terms of the agreement, the collaboration will initially focus on long-acting oral formulations and long-acting injectable formulations of these combination products, with other formulations potentially added later on.

Across the oral and injectable formulation programmes, Gilead and Merck will share global development and commercialisation costs 60 percent to 40 percent, respectively. For both long-acting oral products, Gilead will lead commercialisation in the US and Merck will lead commercialisation in the EU and rest of the world. For long-acting injectable products, Merck will lead commercialisation in the US and Gilead will lead commercialisation in the EU and rest of the world.

Merck and Gilead will share global product revenues equally until product revenues surpass certain pre-agreed per formulation revenue tiers. Upon passing $2 billion a year in net product sales for the oral combination, the revenue split will adjust to 65 percent Gilead and 35 percent Merck for any revenues above the threshold. Upon passing $3.5 billion a year in net product sales for the injectable combination, the revenue split will adjust to 65 percent Gilead and 35 percent Merck for any revenues above the threshold.

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 and 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 this option following completion of the first Phase I 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.