Dive Brief:
- Paris-based biotech Abivax's shares have more than doubled on the news of a successful Phase 2a trial, climbing to $19.70 by market close on Tuesday.
- Treatment with ABX464 in addition to current anti-retroviral treatment reduced the reservoirs of the virus in the blood as measured by HIV DNA in peripheral blood mononuclear cells (PBMCs). The number of viral DNA copies per PBMC, a standard biomarker for viral load, dropped by between 27% and 67% in half of the ABX464-treated patients, who also received anti-retrovirals.
- The primary endpoint of the ABX464-004 trial was safety. There were no severe adverse events and the drug was well tolerated.
Dive Insight:
After decades of research and treatment experience, a diagnosis of HIV infection is no longer a death sentence for the 1.2 million people across the U.S. who carry the virus. However, while correct treatment can get viral load down to sometimes undetectable levels, they have no impact on the pools of infected immune cells lying dormant in the blood, brain, gut and lymph nodes. This is why the breakthrough from Abivax, a small French biotech with only two drugs in clinical development, is so significant, and why the company's share price has more than doubled.
"This is the first time we see a signal with any therapeutic candidate that it may be possible to reduce HIV reservoirs in patients. Now we are looking forward to learn how this drug can be optimized to be part of a multi-target approach to further reduce the viral reservoir," Linos Vandekerckhove, head of the HIV Cure Research Center at the University of Ghent, Belgium, and one of the lead investigators, explained.
More research is needed, and Abivax's parallel study looking at HIV load in gut reservoirs is ongoing. Based on the positive outcome of the blood study, the company plans to extend the treatment period to look at longer-term effects. Initial results from the gut study are expected in the third quarter of 2017.
Norwegian company Bionor is also aiming for a functional HIV cure with its therapeutic vaccine Vacc-4x. Rather than reducing or eradicating the virus using an antiviral — as in Abivax's approach — Vacc-4x uses the patient's immune system to keep the virus levels low. In the REDUC study, combining Vacc-4x with Celgene's romidepsin cut the latent HIV reservoir by 40%, with viral load below detection in 11 of 17 patients.