Phase III ATLAS-2M study of cabotegravir and rilpivirine meets primary endpoint at 48 weeks in HIV.- ViiV Healthcare

ViiV Healthcare has presented positive 48-week data from its global phase III ATLAS-2M study of long-acting, injectable, 2-drug regimen (2DR) of ViiV Healthcare’s cabotegravir and Janssen’s rilpivirine for the treatment of HIV. The study met its primary endpoint at Week 48, showing that the antiviral activity and safety of long-acting cabotegravir and rilpivirine administered every eight weeks (two months) was non-inferior when compared to its administration every four weeks (monthly). In the global phase III ATLAS-2M study, non-inferiority was determined by comparing the proportion of participants with plasma HIV-1 RNA of at least 50 copies per millilitre (c/mL) using the FDA Snapshot algorithm at Week 48 (Intent-to-Treat Exposed [ITTE] population), which showed that the two-month arm (9/522 [1.7%]) and one-month arm (5/523 [1.0%]) were similarly effective (adjusted difference: 0.8%, 95% confidence interval [CI]: -0.6, 2.2). The study also found that rates of virologic suppression (HIV-1 RNA less than 50 c/mL), a key secondary endpoint for ATLAS-2M, were similar, whether the regimen of cabotegravir and rilpivirine was administered every two months (492/522 [94.3%]) or once monthly (489/523 [93.5%]) (adjusted difference: 0.8%, 95% CI: -2.1, 3.7). Confirmed virologic failure (CVF) was defined as consecutive viral loads above 200 copies per ml; eight participants in the every-two-month arm (8/522 [1.5%]) and two participants in the monthly arm (2/523 [0.4%]) developed CVF, respectively. On-treatment resistance-associated mutations to rilpivirine, cabotegravir, or both agents were found in five of eight instances of CVF in the two-month arm and both CVF instances in the one-month arm. Treatment with cabotegravir and rilpivirine was generally well-tolerated across both study arms.Comment: ATLAS-2M is being conducted in adults living with HIV-1 infection whose viral load is suppressed and whose virus is not resistant to cabotegravir or rilpivirine. These data were presented at the 2020 Conference on Retroviruses and Opportunistic Infections.