Abivax, buoyed by HIV milestone, leads surge in value of biotech stocks in Paris

Abivax's share price has surged more than 160% in a little more than one trading session. Investors drove up the stock on the back of news regarding its HIV collaboration, sparking a chain of events that saw the share prices of a clutch of biotech stocks surge on the Paris exchange.

Paris-based Abivax (EPA:ABVX) experienced the most dramatic rise, gaining 87% one day and continuing the rapid upswing the next morning. The surge followed an update on the Abivax-led Project CaReNa, a Bpifrance-backed scheme that pairs the French biotech with Theradiag and the French National Center for Scientific Research to develop HIV drugs and diagnostics targeting protein-RNA interactions.

As a result of progress with ABX464, an HIV antiviral, Project CaReNa has now completed its second key milestone, news that was disclosed in a statement this week. The drug is yet to advance beyond Phase II--a Phase IIa trial to assess the long-term effect of ABX464 on viral load is due to report early data later this year--but, with Abivax’s share price depressed by a setback to its hepatitis B vaccine, the news was enough to send its stock on a two-day tear.

The jump, which moved Abivax’s share price up to levels last seen before the hepatitis B blow, was the most meteoric rise on a busy period for traders in Paris. Biophytis (EPA:ALBPS) rose 35% in early trading on Thursday, despite its most recent statement--a trial start update that failed to move the stock--being published 48 hours earlier. Shares in TxCell (EPA:TXCL) spiked more than 10% before falling back toward earth. Sensorion (EPA:ALSEN) and Genticel (EPA:GTCL) both rose, too.

Each of the biotechs has a small market cap--Abivax leads the pack at €97 million ($109 million)--and on a typical day is traded in relatively small volumes. For a short window on Thursday, those volumes increased sharply, as did the share prices and market caps of the companies caught up in the trading frenzy.