A novel investigational combination of islatravir (ISL) from Merck and lenacapavir (LEN) from Gilead Sciences has achieved positive topline results in two phase 3 studies treating HIV.
Islatravir is a next-generation nucleoside analog that, among other mechanisms of action, uses reverse transcriptase translocation inhibition. Lenacapavir is a first-in-class capsid inhibitor that disrupts HIV at multiple stages of its life cycle. The once-weekly tablet of ISL/LEN contains 2 mg of islatravir and 300 mg of lenacapavir, treating patients with HIV who are virologically suppressed.
In the ISLEND-1 and ISLEND-2 trials, the combination met its primary efficacy endpoint, defined by the percentage of participants with HIV-1 RNA levels of ≥ 50 copies/mL at week 48. Patients in the trial switched from Biktarvy (bictegravir 50 mg/emtricitabine 200 mg/tenofovir alafenamide 25 mg). ISL/LEN was found to be statistically non-inferior to Biktarvy.
These results follow a positive phase 2 clinical study, where the regimen maintained viral suppression at week 24.