Benzinga | Oct 26, 2021 06:48AM EDT

Gilead and Merck Initiate Phase 2 Study Evaluating an Oral Weekly Combination Regimen of Investigational Lenacapavir and Investigational Islatravir for HIV-1 Treatment in Virologically Suppressed Adults

Gilead Sciences, Inc. (NASDAQ:GILD) and Merck (NYSE:MRK), known as MSD outside the United States and Canada, today announced the start of a Phase 2 clinical study evaluating an investigational once-weekly oral combination treatment regimen of islatravir and lenacapavir in people living with HIV who are virologically suppressed on antiretroviral therapy.

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"Partnerships and collaborations are critical to continuing the tremendous progress that has been made toward ending the HIV epidemic," said Jared Baeten, MD, PhD, Vice President, HIV Clinical Development, Gilead Sciences. "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. 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."

Through the collaboration between Merck and Gilead, announced in March 2021, the companies seek to build on their legacies of transforming HIV care by focusing on long-acting therapies, which may 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 Dr. Joan Butterton, vice president, global clinical development, infectious diseases, Merck Research Laboratories.

Both islatravir and lenacapavir have long half-lives and have demonstrated activity at low dosages in independent clinical studies, which support the development as an investigational combination regimen with long-acting formulations, both oral and injectable. While daily, single tablet oral regimens are available for people living with HIV, oral or injectable regimen options that allow for less frequent dosing have the potential to address preference considerations, as well as issues associated with stigma, adherence, and privacy.

The Phase 2 study is designed to evaluate the safety and antiviral effect of an oral weekly regimen of Merck's investigational nucleoside reverse transcriptase translocation inhibitor, islatravir, in combination with Gilead's investigational capsid inhibitor, lenacapavir. The primary endpoint is the proportion of study participants with HIV-1 RNA viral load 50 c/mL at Week 24.

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

There is currently no cure for HIV or AIDS.