First Evidence of Treatment-Induced Reduction in HIV Reservoirs

Small molecule inhibits biogenesis of viral RNA

Abivax, a biotechnology company based in Paris, France, has announced that its lead therapeutic candidate, ABX464, is the first treatment to reduce human immunodeficiency virus (HIV) reservoirs in chronically infected patients, as measured by total HIV DNA detected in peripheral blood mononuclear cells (PBMCs). ABX464 is a first-in-class small molecule that inhibits the biogenesis of the viral RNA required for replication of HIV viruses.

In a phase 2a study, 30 patients with HIV infections in Spain, Belgium, and France received either ABX464 or matching placebo in addition to their current antiretroviral treatments for 28 days. The viral load at the start of the study was controlled with boosted darunavir. After the 28-day treatment period, both ABX464 and placebo were interrupted until the viral load rebounded. Baseline and day-28 blood samples were obtained to assess the potential effect of ABX464 on HIV reservoirs in PBMCs.

Among evaluable patients, a reduction in viral DNA copies in mPBMCs was observed in seven of 14 treated patients, for a mean change of –40% (range, –27% to –67%), while no responses were observed in four placebo-treated patients. Responders were defined as patients who had reductions of greater than 25% in total HIV DNA in PBMCs and reductions of at least 50 copies.

Abivax has initiated another phase 2a trial to investigate the effects of ABX464 on HIV reservoirs in gut tissues.

Source: Abivax; May 2, 2017.