enGene Therapeutics said on November 11 that updated results from the pivotal first cohort of its Phase 2 LEGEND trial support starting a Biologics License Application for detalimogene voraplasmid by the end of 2026. The cohort enrolled 125 patients with high-risk, BCG-unresponsive non-muscle invasive bladder cancer with carcinoma in situ, with or without papillary disease, and 120 patients were efficacy evaluable at the October 29, 2026 data cutoff.
The headline response rate moved only slightly. Complete response at any time reached 56 percent (95 percent confidence interval 47 to 65 percent), up from 54 percent in the April 2026 analysis. The improvement was in durability: the preliminary Kaplan-Meier estimate of responses lasting at least 12 months rose to 43 percent from 25 percent, median duration of response lengthened to 10.1 months from 8.6 months, and the landmark 12 month complete response rate doubled to 24 percent from 13 percent. Tolerability held, with 2 percent of patients experiencing a serious treatment related adverse event.
The company said a pre-BLA meeting with the FDA produced alignment on the efficacy evaluable population. It expects to complete the submission in the first half of 2027, with potential approval in 2027. Detalimogene, a non-viral plasmid gene therapy instilled directly into the bladder, holds Regenerative Medicine Advanced Therapy and Fast Track designations, and enGene says it would be the first and only non-viral plasmid gene therapy suited to any urology practice setting if approved.
The update is a partial rehabilitation of a dataset the market punished in May, when an earlier LEGEND readout sent the stock down sharply over durability doubts. The shares recovered about 20 percent on November 12 in market coverage of the new data. The caveats have not changed: LEGEND is single arm and open label, the duration estimates are preliminary, and cross trial comparisons in this indication remain contested. What has changed is that the weakest part of the May story, how long responses last, is now the strongest part of the filing case.