The U.S. Food and Drug Administration has approved Merck’s HIV drug Idvynso, giving some adults with virologically suppressed HIV-1 a new once-daily oral treatment option. Merck said the drug combines doravirine and islatravir in a two-drug regimen designed to replace an existing antiretroviral treatment in eligible patients.
Merck said Idvynso is approved for adults with virologically suppressed HIV-1 who have no history of treatment failure and no known resistance-associated substitutions to doravirine. The approval gives the company a new branded HIV product that builds on doravirine, which Merck already markets in the United States as Pifeltro and in the single-tablet regimen Delstrigo.
HIV-1 is the most common form of the virus that causes AIDS. The World Health Organisation says 40.8 million people were living with HIV at the end of 2024, while an estimated 1.3 million people acquired the virus that year. Those figures underline the continued demand for new treatment options and simplified regimens.
Merck said two late-stage studies involving more than 1,000 patients showed that the doravirine and islatravir combination significantly suppressed HIV-1 replication in adults who were already receiving treatment. In an earlier company update, Merck also said the regimen demonstrated non-inferior efficacy compared with Gilead’s Biktarvy in a Phase 3 pivotal trial, suggesting viral suppression similar to that of a widely used standard-of-care option.
In Merck’s announcement, Dr. Eliav Barr said Idvynso expands therapeutic diversity beyond the oral treatment options already on the market. That matters because HIV care increasingly focuses not only on viral suppression, but also on long-term tolerability, treatment simplicity, and choice for patients whose needs may change over time. Merck has also said islatravir remains under study in several combinations for both daily and once-weekly HIV-1 treatment approaches.
The approval marks an important milestone for Merck, but investors may watch the longer-term use more closely than the immediate sales.
