News: Majority of patients with post-BCG bladder cancer achieve CR with nonviral gene therapy
More than half of patients with previously treated non-muscle invasive bladder cancer (NMIBC) had complete responses (CR) with an intravesical gene therapy, according to preliminary results from an ongoing study.
The interim data from the study showed that 54% of 125 patients had a CR with detalimogene voraplasmid, and the 12-month CR rate was a 25%. Among patients attaining CRs, 84% remained in CR at the nine-month evaluation and 59% remained in CR at the 12-months evaluation.
Fewer than 5% of patients had ≥3 treatment-related adverse events (TRAE), indicating the therapy has been well-tolerated by participants in the study.
The study involves patients whose disease had proven unresponsive to traditional first-line treatment with intravesical bacillus Calmette-Guérin (BCG). Multiple therapies are being developed to help meet that need.
The phase I/II LEGEND study involves patients with high-risk BCG-unresponsive NMIBC, defined as carcinoma in situ with or without high-grade Ta/T1 that is persistent or recurrent within 12 months of BCG treatment. Patients receive intravesical doses of the gene therapy at weeks 1, 2, 5, and 6 of a 12-week cycle, each dose requiring a 16-minute dwell time. Patients not in CR after 12 weeks have the option for a second induction. Maintenance consists of doses on weeks one and two every 12 weeks for a maximum of three years.
The primary endpoint is CR at any timepoint. Secondary endpoints include duration of response (DOR), CR at landmarks, and progression-defined survival.
The 54% of patients who attained CR had a median follow-up of 5.5 months, and 91% of the CRs occurred at the three-month assessment. Median time to CR was 2.4 months. Twenty-two patients have completed the 12-month evaluation, and 21 others have pending evaluations at six to 12 months and potential to achieve CR.
Editor’s note: To read initial findings from the study, click here. To read additional coverage by MedPage Today, click here.