Non-viral genetic medicines company enGene Therapeutics announced on November 11, 2026, that it plans to initiate a biologics license application (BLA) submission for detalimogene voraplasmid (detalimogene) by year-end 2026. The company also reported updated results from pivotal cohort 1 of the phase 2 LEGEND trial in high-risk, Bacillus Calmette-Guérin (BCG)-unresponsive non-muscle invasive bladder cancer (NMIBC).¹ The complete response (CR) rate at any time reached 56%, up from 54% in an April 2026 analysis.¹,²
Key facts
- Drug: detalimogene voraplasmid (enGene Therapeutics)
- Class: Non-viral, intravesical plasmid gene therapy (DDX platform)
- Indication studied: High-risk BCG-unresponsive NMIBC with CIS, with or without papillary disease
- Trial: LEGEND (NCT04752722), pivotal cohort 1; phase 2, n=125
- Primary end point: CR at any time, 56%
- 12-month landmark CR: 24%
- Durability: Estimated 43% DoR ≥12 months; median DoR 10.1 months
- Safety: Serious TRAEs in 2%; no grade 4 or 5 TRAEs
- Regulatory status: BLA submission to begin by year-end 2026 (FDA)
- Designations: RMAT, fast track; CMC Development and Readiness Pilot program
“The updated LEGEND data are encouraging, demonstrating clinically meaningful antitumor activity with a favorable tolerability profile,” said Ashish M. Kamat, MD, professor of urologic oncology at The University of Texas MD Anderson Cancer Center and primary investigator of the LEGEND trial, in a company press release.¹
How did efficacy change as the data matured?
Cohort 1 enrolled 125 patients with BCG-unresponsive NMIBC with carcinoma in situ (CIS), with or without papillary disease. Efficacy was assessed in 120 evaluable patients as of an October 29, 2026, data cutoff.¹ The CR rate at any time was 56% (CI: 47%, 65%), and the landmark 12-month CR rate was 24% (CI: 16%, 33%; n=110), up from 13%.¹
The preliminary Kaplan-Meier estimate of duration of response (DoR) of at least 12 months rose to 43% (CI: 30%, 55%) from 25%. Median DoR rose to 10.1 months (CI: 7.5, not estimable) from 8.6 months.¹,² Median follow-up for responders increased to 12.0 months from 9.2 months.¹
Overall, 97% of evaluable patients were free from progression to T2 or greater disease. Also, 86% remained free from cystectomy, including 96% of responders.¹
What was the safety profile?
Of 125 patients assessed for safety, 59% experienced at least 1 treatment-related adverse event (TRAE), mainly grade 1 or 2.¹ The most common were fatigue (21%), dysuria (16%), pollakiuria (16%), bladder spasm (13%), micturition urgency (13%), and urinary tract infection (10%).¹ Grade 3 TRAEs occurred in 4% of patients and serious TRAEs in 2%, with no grade 4 or 5 events. TRAEs led 1% of patients to discontinue and 4% to interrupt dosing.¹
What are the regulatory next steps?
After a pre-BLA meeting, enGene said it reached alignment with FDA on key components of the application, including the efficacy-evaluable population.¹ The company plans to complete the submission in the first half of 2027, with potential approval in 2027.¹ Detalimogene holds RMAT and fast track designations. It was also selected for FDA's Chemistry, Manufacturing, and Controls Development and Readiness Pilot program.¹
