Merck Once-Daily HIV Treatment Idvynso Approved by FDA

Merck, known as MSD outside the United States and Canada, announced FDA’s approval of its new HIV treatment Idvynso.

Idvynso is a single-tablet, two-drug regimen comprised of 100 mg doravirine and 0.25 mg islatravir. Its indication covers adults with HIV-1 infection—the most common and virulent strain of HIV—and replaces current antiretroviral regimens.

FDA Parameters for Idvynso Approval

Specifically, patients must previously have been virologically suppressed (HIV-1 RNA less than 50 copies per mL) on a stable regimen. Additionally, they must have no history of virologic treatment failure, and no known substitutions associated with a resistance to doravirine.

Eliav Barr, MD, Senior Vice President and Chief Medical Officer, Merck Research Laboratories, applauded the approval.

“Idvynso expands therapeutic diversity beyond the currently available oral treatment options,” Barr said. “As the health needs of adults living with HIV change over time, IDVYNSO gives clinicians a new choice.”

Merck History With HIV Research

Barr noted Merck’s commitment to scientific research and discovery in HIV, which goes back some 40 years. His comments were echoed by Carl Baloney, Jr., President and Chief Executive Officer of AIDS United.

“Advances in HIV treatment mean more people living with HIV are living longer—a remarkable achievement,” Baloney said. “People aging with HIV face additional health challenges, including managing multiple chronic conditions and medications at the same time. It is essential that management of HIV considers these factors in addition to virologic suppression.”

Merck says Idvynso is contraindicated when co-administered with strong cytochrome P450 (CYP)3A enzyme inducers and lamivudine (3TC) or emtricitabine (FTC). Accordingly, co-administration with these drugs may decrease Idvynso’s effectiveness.

Following the FDA approval, Idvynso will be available in U.S. pharmacies as of May 12, 2026.