Infectious disease

Abivax: Evidence of treatment-induced reduction in HIV reservoirs

Abivax just released topline data generated by a Phase IIa study of its small molecule ABX464 in HIV treatment. In a 30 patients placebo controlled trial, Abivax was able to significantly reduce HIV reservoirs:

In the ABX464-004 trial, 30 HIV patients were enrolled in Spain, Belgium and France. Patients were enrolled in a 3:1 randomization, receiving either ABX464 or matching placebo in addition to their current antiretroviral treatment during 28 days. The viral load at the start of the study was well controlled with boosted darunavir. After the 28-day treatment period, all treatments were interrupted until viral load rebound. Baseline and day 28 blood samples were taken in order to assess the potential effect of ABX464 on the HIV reservoir in PBMCs. The clinical trial has been completed with respect to patient treatment and follow-up.

Safety was the primary endpoint in the trial and ABX464 was well tolerated and there were no severe adverse events in the treatment group. Amongst evaluable patients (4 placebo and 14 ABX464-treated patients), a reduction in viral DNA copies/mPBMCs was observed in 7/14 treated patients (mean change of -40%, ranging from -27% to -67%) and no responders were observed in the placebo group. Responders were defined as patients who had a decrease greater than 25% in total HIV DNA in PBMCs and a reduction of at least 50 copies.

ABX464 has a new and innovative mode of action. It inhibits REV activity and thereby modulates viral RNA splicing and blocks export of Unspliced RNA. Abivax also hopes that its treatment does not lead to HIV mutants that are resistant to treatment, which would be a real breakthrough.