Merck Wins USFDA Approval for Dual-Drug HIV Therapy Idvynso

The two-drug combination of doravirine and islatravir, branded as Idvynso, was approved to replace the current antiretroviral regimen for ​treating Human Immunodeficiency Virus-1 infection in some adults.

While islatravir is an ​experimental treatment, Merck's doravirine is approved and sold in the ⁠U.S. under the brand name Pifeltro for HIV-1 treatment in combination with other ​antiretrovirals, and as a single-tablet regimen, Delstrigo.

HIV-1 is the most common strain of ​the retrovirus that causes acquired immunodeficiency syndrome, commonly known as AIDS.

About 40.8 million people are living with HIV globally, and about 1.3 million new infections occur annually, according to ​National Institutes of Health data.

"Idvynso expands therapeutic diversity beyond the currently available oral ​treatment options," said Dr. Eliav Barr, senior vice president and chief medical officer, Merck Research ‌Laboratories.

In ⁠two late-stage studies with more than 1,000 patients, the treatment combination met the main goal of significantly suppressing replication of HIV-1 in adults receiving another form of therapy.

Last year, Merck's oral drug combination was found to be non-inferior to ​Gilead's top-selling drug, Biktarvy, ​achieving similar HIV-1 ⁠suppression to the current standard of care.

While this is a meaningful developmental milestone for Merck, RBC Capital Markets analyst ​Trung Huynh expects initial commercial impact to be limited, with ​the inflection ⁠point being a potential approval in patients who have not received any treatment.

Merck's HIV story is best viewed as a "multi-year build rather than a near-term growth ⁠driver," said ​Huynh.

Islatravir is being tested in multiple trials ​in combination with other antiretrovirals for potential daily and once-weekly treatments for HIV-1.