Merck: Interim Phase 2a data on Once-Monthly, Oral HIV-1 Preventive at IAS 2021

 Merck (NYSE: MRK), known as MSD outside the United States and Canada, today announced results from a Phase 2a clinical trial evaluating the safety, tolerability and pharmacokinetics (PK) of six monthly oral doses, over 24 weeks, of islatravir, the company’s investigational nucleoside reverse transcriptase translocation inhibitor, versus placebo for pre-exposure prophylaxis (PrEP) of HIV-1 infection in adults at low-risk of contracting HIV-1. After 24 weeks, once-monthly oral islatravir was generally well tolerated versus placebo. Most adverse events (AEs) were mild and there were no serious drug-related AEs in people who received islatravir. The levels of islatravir in peripheral blood mononuclear cells (PBMCs) also remained above the pre-specified efficacy PK threshold for PrEP at both doses studied (60 mg and 120 mg) eight weeks after the last study dose. These data were shared as a late-breaking oral presentation during the virtual 11th International AIDS Society Conference on HIV Science (IAS 2021) and are a follow-up to the interim analysis that was presented earlier this year at the virtual 2021 HIV Research for Prevention Conference (HIVR4P 2021).

“The 24-week analysis of investigational, once-monthly oral islatravir not only builds upon the PK data we have already seen, but also provides encouraging support for the safety and tolerability profile of this HIV-1 PrEP regimen,” said Dr. Joan Butterton, vice president, global clinical development, infectious diseases, Merck Research Laboratories. “As part of our commitment to understanding the potential for our HIV medicines in a broad range of patients, we focused on the enrollment of diverse patient populations at risk for HIV, including women, who have one of the highest unmet needs in HIV prevention.”

Islatravir is currently being evaluated across a variety of dosing regimens, for both the treatment of HIV-1 infection in combination with other antiretroviral agents and for the prevention of HIV-1 infection as a monotherapy. An overview of the islatravir treatment and prevention development program is available here, which includes our two Phase 3 IMPOWER trials evaluating islatravir as once-monthly oral PrEP across diverse populations of people who may benefit from additional HIV-1 prevention options.

https://www.businesswire.com/news/home/20210720005219/en/Merck-Presents-New-Data-from-Ongoing-Phase-2a-Clinical-Trial-Evaluating-the-Safety-Tolerability-and-Pharmacokinetics-of-Investigational-Once-Monthly-Oral-Islatravir-for-HIV-1-Prevention-at-IAS-2021