enGene’s Phase II LEGEND update for its nonviral gene therapy detalimogene in high-risk BCG-unresponsive NMIBC showed lower complete response and durability than prior readouts, triggering a sharp market reaction. In the April 21 data cutoff, 54% of evaluable patients achieved complete response at any time, dropping to 43% at six months, down from earlier figures reported for the initial patients. The company plans to present at the AUA Annual Meeting. The update raises near-term commercial and regulatory scrutiny around durability, even as enGene reiterated plans to continue discussions with the FDA and await longer-term data for Cohort 1.