enGene’s stock plunged after updated Phase II results for its nonviral gene therapy candidate detalimogene voraplasmid in high-risk, BCG-unresponsive non-muscle invasive bladder cancer. The update reportedly lowered complete response metrics versus prior company expectations, increasing scrutiny around durability and benchmark performance. The report cited an April 21 data cutoff showing 54% complete response (CR) at any time and 43% CR at six months, down from earlier readouts. It also described lower longer-term CR rates after treatment, underscoring concerns about durability. enGene said durability outcomes are preliminary, that longer-term data are planned, and it intends to continue discussions with the FDA regarding potential filing strategies.