enGene’s shares plunged after updated Phase II LEGEND trial data for its nonviral gene therapy candidate, detalimogene (formerly EG-70), in high-risk BCG-unresponsive nonmuscle invasive bladder cancer with carcinoma in situ (CIS±papillary). The updated readout showed complete response durability falling from earlier results, including a six-month CR drop versus the company’s prior cohort.