In a significant development for HIV care, global pharma giant Merck announced that the US FDA has approved IDVYNSO, a new single-tablet, two-drug regimen for adults living with HIV-1 who are already virologically suppressed.
The newly approved pill combines 100 mg of doravirine with 0.25 mg of islatravir, offering a simplified option for patients currently stable on antiretroviral therapy. The treatment is designed to replace existing regimens in adults with HIV-1 RNA levels below 50 copies per mL, provided they have no history of treatment failure or resistance to doravirine.
“Advances in HIV treatment mean more people living with HIV are living longer — a remarkable achievement,” said Carl Baloney, Jr., president and chief executive officer of AIDS United.
“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 when choosing an HIV treatment regimen.”
Merck says the drug marks a shift in available therapies. Unlike many existing treatments, IDVYNSO is a two-drug regimen that avoids both integrase inhibitors and tenofovir, broadening options for clinicians and patients alike.
“IDVYNSO combines islatravir, a next-generation NRTI with multiple mechanisms of action, including translocation inhibition, with doravirine, an NNRTI with an established efficacy and safety profile.
"As the only two-drug, non-INSTI, tenofovir-free regimen, IDVYNSO expands therapeutic diversity beyond the currently available oral treatment options,” said Eliav Barr, senior vice president and chief medical officer, Merck Research Laboratories.
“As the health needs of adults living with HIV change over time, IDVYNSO gives clinicians a new choice for HIV treatment. This approval marks an important new chapter in Merck’s long-standing commitment to research and discovery for people living with HIV.”
The approval is backed by clinical data showing the drug performs on par with leading therapies, including BIKTARVY.
“IDVYNSO is the first non-INSTI, tenofovir-free, two-drug regimen to demonstrate non-inferior efficacy to standard oral antiretroviral regimens, including BIKTARVY. This makes IDVYNSO a potential alternative for people with virologically suppressed HIV who may need to switch their treatment,” said Amy Colson, director of research at Community Resource Initiative, Boston, Massachusetts.
Still, the drug comes with important safety considerations. IDVYNSO should not be taken alongside strong CYP3A enzyme inducers or certain other HIV medications such as lamivudine or emtricitabine, as these combinations may reduce its effectiveness.
Serious side effects, including severe skin reactions like Stevens-Johnson syndrome and drug hypersensitivity reactions, have also been reported.
Despite these cautions, the approval signals another step forward in the long-running effort to refine HIV treatment—offering patients fewer drugs, fewer complications, and more flexibility in long-term care.
