The U.S. FDA approved Merck's once-daily oral two-drug combination of doravirine (100 mg) and islatravir (0.25 mg), branded as Idvynso, for treating HIV-1 in virologically suppressed adults as a regimen switch.134
Approval announced on April 21, 2026, supported by Week 48 data from Phase 3 trials MK-8591A-051 and MK-8591A-052 involving 708 participants.45
In Trial 052, 1% of Idvynso switchers had viral load ≥50 copies/mL at Week 48 vs. 1% on Biktarvy; in Trial 051, 1% vs. 5% on baseline therapy.4
Doravirine is already approved as Pifeltro; islatravir is investigational; regimen is non-inferior to three-drug standards without an integrase inhibitor.15
Sources:
1. https://www.marketscreener.com/news/us-fda-approves-merck-s-combination-hiv-treatment-ce7f59dbdd8af526
3. https://www.investing.com/news/stock-market-news/us-fda-approves-mercks-combination-hiv-treatment-4626858
4. https://au.investing.com/news/company-news/fda-approves-mercks-idvynso-for-hiv1-treatment-switch-93CH-4375037
5. https://www.merck.com/news/u-s-fda-accepts-new-drug-application-for-mercks-doravirine-islatravir-an-investigational-once-daily-oral-two-drug-regimen-for-treatment-of-adults-with-virologically-suppressed-hiv-1-infe/