Merck’s New HIV Treatment Matches Leading Drug in Trials

Merck & Co. Inc. has announced promising results from two Phase 3 trials of its new HIV treatment, a two-drug regimen combining doravirine and islatravir (DOR/ISL). The findings indicate that this new treatment is as effective as the current leading medication, bictegravir/emtricitabine/tenofovir alafenamide (BIC/FTC/TAF), sold under the brand name Biktarvy by Gilead Sciences Inc.. The data will be presented at the upcoming 20th European AIDS Conference.

In the trials, specifically named MK-8591A-052 and MK-8591A-051, participants who switched to DOR/ISL from the three-drug regimen maintained viral suppression without developing resistance to either drug. The results showed that DOR/ISL demonstrated non-inferiority to BIC/FTC/TAF, with both treatments effectively managing HIV-1 infections in adults.

Clinical data from the MK-8591A-052 trial revealed minimal differences in weight and body composition among participants. Those who transitioned to the DOR/ISL regimen after being on BIC/FTC/TAF experienced an average weight change of -0.03 kg, compared to a weight increase of +0.28 kg in the BIC/FTC/TAF group. Furthermore, only 14.6% of the DOR/ISL group experienced a weight gain of 5% or more from baseline, compared to 16.0% in the BIC/FTC/TAF group.

Clinical Outcomes and Safety Profiles

Both trials indicated that participants switching to DOR/ISL showed no significant changes in fasting lipids or insulin resistance levels. The mean changes in fasting lipid profiles, including total cholesterol and triglycerides, were consistent across both treatment groups. Specifically, the proportion of participants requiring adjustments to their diabetes medication remained comparable, with DOR/ISL at 4.8%, BIC/FTC/TAF at 4.1%, and baseline antiretroviral therapy (bART) at 5.9%.

The investigational treatment is currently under review by the U.S. Food and Drug Administration (FDA), which accepted the New Drug Application for DOR/ISL earlier this year. The FDA has set a target action date of April 28, 2026, for its decision.

As of the publication date, Merck & Co. shares were trading at $83.89, reflecting a decline of 0.96%. The company’s ongoing research underscores the significant potential of DOR/ISL to offer an effective alternative for those living with HIV-1, contributing to the evolving landscape of HIV treatment options.

The outcomes of these trials could have considerable implications for the treatment of chronic diseases, particularly as the healthcare community continues to seek innovative and effective therapies for HIV management.