- Dual therapy with MK-8591 in combination with doravirine (DOR) was well-tolerated while participants achieved and maintained viral suppression among all treatment groups in study assessing efficacy and safety data.
Why this matters
- MK-8591 (islatravir) is the first nucleoside reverse transcriptase translocation inhibitor in development for treatment of HIV-1 infection.
- DOR is a recently approved non-nucleoside reverse transcriptase inhibitor.
- Phase 2B, double-blind, comparator-controlled, dose-ranging trial to evaluate efficacy and safety of MK-8591 with DOR.
- 121 patients (mean age, 31 years; 92.6% male, 76.0% white, 22% HIV-1 RNA >100,000 copies/mL) were randomly allocated to 1 of 4 study arms.
- First 24 weeks, equal number of patients received 1 of 3 doses of MK-8591 (0.25, 0.75, or 2.25 mg) plus DOR (100 mg) and 3TC (lamivudine; 300 mg) or DOR/3TC/TDF (tenofovir disoproxil) once daily with placebo.
- After 24 weeks, those on MK-8591 who achieved HIV-1 RNA
- Efficacy endpoints included overall proportion of patients at week 48 with HIV-1 RNA
- Safety was assessed by adverse event reporting.
- Proportion of patients achieving HIV-1 RNA
- 0.25 mg, 89.7%;
- 0.75 mg, 90.0%;
- 2.25 mg, 77.4%; and
- With DOR/3TC/TDF, 83.9%.
- MK-8591, any dose (combined 7.8%).
- DOR/3TC/TDF (19.4%).
- Conference presentation reported without peer review.
- “These are promising data that encouraged the company to move to a phase 3 trial to see how these results can confirm in a larger study site and also to assess this dual combination for therapy in the future providing novel options for people,” said Jean-Michel Molina, the study’s lead investigator from Paris Diderot University and Saint-Louis Hospital, during a press conference.