Gilead, Merck Initiate Phase 2 Study for HIV Treatment in Adults

Gilead and Merck recently announced the start of a Phase 2 clinical study evaluating a combination HIV treatment regimen in adults living with the disease.

The open-label study will evaluate the weekly oral regimen of Gilead’s islatravir combined with Merck’s lenacapavir in virologically suppressed individuals with HIV across 25 sites in the US. 

Researchers will randomly assign patients to receive 20 milligrams of islatravir along with 300 milligrams of lenacapavir on day eight following a loading dose of islatravir 40 milligrams and lenacapavir 600 milligrams. 

The primary endpoint of the study is the proportion of study participants with HIV-1 RNA viral load greater than 50 cups/milliliters at Week 24.

“This innovative research collaboration builds on the efforts of both companies to help make the end of the epidemic a reality through continued scientific advances in HIV,” Jared Baeten, MD, PhD, vice president of HIV clinical development at Gilead, said in the announcement.

“Initiating the trial represents an important step forward toward our goal of offering long-acting options that can help address the differentiated needs and preferences of the diverse range of people living with HIV,” Baeteb continued. 

Islatravir and lenacapavir are potentially first-in-class medicines in late-stage clinical trials. So far, both drugs have elicited strong responses at low dosages in clinical studies.

Although daily, single-tablet oral regimens are available for individuals with HIV, oral or injectable regimens that require less frequent dosing can address preference considerations and issues associated with stigma, adherence, and privacy, a Gilead spokesperson explained. 

In March 2021, Merck and Gilead announced their collaboration to co-develop and co-commercialize long-acting treatments in HIV that combine lenacapavir and islatravir into a two-drug regimen. 

Both companies are focused on transforming HIV care by focusing on long-acting therapies that could represent a meaningful innovation in HIV drug development. 

“The initiation of this study is key to further understanding the potential of islatravir and lenacapavir in combination for the treatment of HIV-1, and demonstrates Merck and Gilead’s shared commitment to address the unmet needs of people living with HIV and to contribute to global efforts to end the pandemic,” said Joan Butterton, MD, vice president, global clinical development of infectious diseases at Merck.