FX.co ★ Gilead And Merck Report Phase 2 Results For Islatravir And Lenacapavir Combination In HIV Treatment

Gilead Sciences Inc. (GILD) and Merck & Co Inc. (MRK) have unveiled new findings from a Phase 2 clinical study exploring the investigational combination of islatravir, a nucleoside reverse transcriptase translocation inhibitor under investigation, with lenacapavir, a pioneering HIV-1 capsid inhibitor.

After 48 weeks, this novel investigational regimen sustained a remarkable level of viral suppression among virologically stable adults, marking a secondary milestone of the study. Notably, no participants exhibited a viral load of 50 copies/mL or higher at the 48-week mark.

The study, which was open-label and active-controlled, involved adult participants (n=104) who were virologically suppressed while on Biktarvy (bictegravir 50 mg/emtricitabine 200 mg/tenofovir alafenamide 25 mg tablets, B/F/TAF). Participants were randomly assigned in a 1:1 ratio to receive either a weekly oral dose of islatravir 2 mg combined with lenacapavir 300 mg (n=52) or to continue the daily administration of Biktarvy (n=52). The median age of the participants was 40 years (ranging from 20 to 76), with 18% classified as female at birth, 50% identified as non-white, and 29% as Latino.

Assessing the proportion of individuals with HIV-1 RNA levels below 50 c/mL at Week 48, using the FDA snapshot algorithm (a secondary objective), the study demonstrated that both the cohort transitioning to the weekly islatravir and lenacapavir treatment (ISL + LEN) and those continuing on Biktarvy sustained similar high rates of HIV suppression at Week 48 (94.2% versus 92.3%, respectively). Notably, none of the participants on either ISL + LEN or Biktarvy exhibited a viral load reaching or exceeding 50 copies/mL at Week 48.

Gilead Sciences highlighted that 19.2% of participants in the ISL + LEN group experienced treatment-related adverse events, with the most frequent being dry mouth and nausea. In contrast, 5.8% of the Biktarvy group (n=3/52) reported such events. No treatment-related adverse events of grade 3 or 4 severity were associated with the study drug in either group. Two individuals from the ISL + LEN group discontinued the treatment due to adverse events unrelated to the medication. By Week 48, no noteworthy differences were observed between the two treatment groups in terms of mean change from baseline in CD4+ T-cell counts or absolute lymphocyte counts. Additionally, no participants discontinued due to a decrease in CD4+ T-cell or lymphocyte counts.