Plasma samples were collected for analysis of HIV-1 RNA. Mean change in log10 HIV-1 RNA from Day 1 was estimated using analysis of covariance (ANCOVA) with log10 HIV-1 RNA change from Day 1 at Day 8 as dependent variable, treatment (fostemsavir or placebo) as an independent variable, and Day 1 log10 HIV-1 RNA as a continuous covariate. Change from Day 1 was calculated as value at Day 8 minus value at Day 1. The analysis was performed on Intent-to-Treat Exposed (ITT-E) Population which comprised of all randomized participants who received at least one dose of study treatment. Missing HIV-1 RNA values at Day 8 were imputed using (a) Day 1 Observation Carried Forward (D1OCF) for participants without a value during blinded treatment (i.e, imputing a zero change from Day 1) or (b) Last Observation Carried Forward (LOCF) for participants with an early value during blinded treatment before the Day 8 analysis visit window.

The primary assessment of the antiviral activity of BMS-663068 was assessed on the log10 change from Baseline in HIV RNA to Day 9. Baseline was the last non-missing observation before first dose (Day 1 pre-dose) and change from Baseline was calculated by subtracting Baseline value from post-Baseline visit value. An analysis of covariance (ANCOVA) model correcting for Baseline HIV viral load and treatment group was used to test the differences in mean log10 decrease in HIV RNA at Day 9 between 2 regimen groups by antiretroviral treatment history (ARV \[antiretroviral\] naive, ARV experienced, and combined \[ARV naive + ARV experienced\]). For the combined group (ARV naive +ARV experienced) an additional ANCOVA was used correcting also for treatment history as an additional covariate. Only Clade B participants were included in the population.

To assess the effect of varying degrees of renal impairment on the exposure of BMS-626529 after a single oral-dose administration of the pro-drug, BMS-663068, will be evaluated by assessing the primary endpoints of Cmax, for BMS-626529.