ViiV Healthcare and Janssen Pharmaceutical announced positive 48-week data from the phase 3 ATLAS (N=616) and FLAIR (N=566) studies evaluating a long-acting injectable formulation of cabotegravir (ViiV) + rilpivirine (Janssen) in patients with HIV-1 infection. The full data were presented at the 2019 Conference on Retroviruses and Opportunistic Infections (CROI) in Seattle.
The 2 multicenter, open-label, parallel-group studies demonstrated that cabotegravir + rilpivirine administered by intramuscular injection every 4 weeks was non-inferior to a standard of care 3-drug oral regimen in maintaining viral suppression in adults with HIV-1 infection (primary endpoint), as measured by the proportion of patients with HIV-1 RNA ≥50 copies/mL at week 48.
In both studies, virologic suppression rates (HIV-1 RNA <50 copies/mL) were found to be similar between the 2 treatment arms at week 48:
- ATLAS: cabotegravir + rilpivirine: 92.5% vs standard of care (2 nucleoside reverse transcriptase inhibitors + third agent) 95.5%; adjusted difference: -3%, (95% CI, -6.7, 0.7)
- FLAIR: cabotegravir + rilpivirine: 93.6% vs Triumeq (abacavir/dolutegravir/lamivudine): 93.3%; adjusted difference: 0.4% (95% CI, -3.7, 4.5)
The cabotegravir + rilpivirine combination was well-tolerated in both studies; rates of serious adverse events were low (4.2% in ATLAS and 6.4% in FLAIR). During the study period, injection site reactions were reported in 83% of patients in ATLAS and 86% of patients in FLAIR.
In both studies, patients who switched to cabotegravir + rilpivirine from their previous oral therapy demonstrated a significant improvement in treatment satisfaction compared to those who remained on the oral regimen at week 44 (measured by the HIV Treatment Satisfaction Questionnaire). In ATLAS, the data revealed that 86.4% of patients preferred the long-acting injectable regimen vs 2.3% of patients who preferred their previous oral therapy. Similarly in FLAIR, 90.8% of patients preferred the long-acting injectable regimen vs 0.7% of patients who preferred their previous oral therapy.
“If approved, this 2-drug regimen would give people living with HIV 1 month between each dose of antiretroviral therapy, changing HIV treatment from 365 dosing days per year, to just 12,” said John C. Pottage, Jr., MD, Chief Scientific and Medical Officer of ViiV Healthcare.
Rilpivirine, a non-nucleoside reverse transcriptase inhibitor (NNRTI), is currently approved to treat HIV in combination with other antiretrovirals, while cabotegravir is an investigational integrase inhibitor.