The drugmaker has been viewed as a near-term takeover target for Big Pharma.

A handful of cancer cases reported among treatment recipients overshadowed efficacy results analysts described as “best-in-disease” and sent shares down more than 30%.

Shares of French biotech Abivax tumbled 32% after it reported fresh data on its lead asset.

"The cancer signal complicates matters."

Jefferies downgraded the French biotech to Hold and cut its price target nearly in half, warning the cancer overhang won't resolve quickly

The drugmaker has been viewed as a near-term takeover target for Big Pharma.