enGene Therapeutics Inc. (NASDAQ: ENGN) reported interim results from its Phase 2 LEGEND trial of detalimogene voraplasmid in patients with high-risk, BCG-unresponsive non-muscle invasive bladder cancer.

The trial enrolled 125 patients with carcinoma in situ with or without concomitant papillary disease. Results as of April 21, 2026, showed a 54% complete response rate at any time and a 43% complete response rate at six months. The progression rate to muscle-invasive or advanced disease was 3.2%.

The Kaplan-Meier estimate of the 12-month complete response rate was 25%. The median duration of response was 37.3 weeks.

Among 32 patients who had their first disease assessment after the previous data analysis in October 2025, response rates were lower, with a 39% complete response rate at any time and 32% at six months.

Treatment-related adverse events occurred in 55% of patients, with 91% of those being Grade 1-2 severity. Grade 3 or higher treatment-related adverse events were reported in 4.8% of patients. Treatment interruptions due to adverse events occurred in 2.4% of patients, and discontinuations occurred in 2.4%.

"While durability outcomes to date are not what we hoped, these data are preliminary," said Ron Cooper, President and Chief Executive Officer of enGene. "We are focused on evaluating the totality of the data as it evolves and plan to continue to engage with the FDA and the medical community."

The company has completed FDA manufacturing validation batches and submitted a Statistical Analysis Plan to the agency. enGene plans to provide an update on potential Biologics License Application filing in the second half of 2026.

Detalimogene has received Regenerative Medicine Advanced Therapy and Fast Track designations from the FDA. The company plans to present data at the American Urological Association meeting on May 15, 2026.