SunRISe-1: TAR-200 in BCG-Unresponsive High-Risk NMIBC

Results of the phase 2b SunRISe-1 trial showed TAR-200, an intravesical drug delivery system, yields complete responses (CRs) in Bacillus Calmette-Guérin (BCG)-unresponsive high-risk non-muscle invasive bladder cancer (HR NMIBC).

Andrea Necchi, MD, of the San Raffaele Hospital and Scientific Institute (Italy), presented the results as a late-breaking abstract at the European Society for Medical Oncology Congress 2023.

Patients with BCG-unresponsive HR NMIBC have limited treatment options. TAR-200 provides sustained release of gemcitabine in the bladder over the course of a few days.

The ongoing, randomized SunRISe-1 trial is assessing the safety and efficacy of TAR-200 plus cetrelimab (cohort 1) versus TAR-200 alone (cohort 2) or cetrelimab alone (cohort 3) in patients with BCG-unresponsive HR NMIBC who are ineligible for or refuse radical cystectomy.

Dr. Necchi reported the results from cohort 2. TAR-200 was dosed once every 3 weeks through week 24, then once every 12 weeks until week 96. Response assessments included cystoscopy and centrally assessed urine cytology, computed tomography/magnetic resonance imaging, and bladder biopsy (at weeks 24, 48, and as clinically indicated).

The primary end point was overall CR rate. Secondary end points included duration of response (DOR), overall survival, safety, and tolerability.

At data cutoff, 54 patients had received TAR-200 monotherapy, 30 of whom were evaluable for efficacy. Centrally confirmed CR by urine cytology or biopsy was achieved in 77% of patients (n=23; 95% CI, 58%-90%). Additionally, Dr. Necchi mentioned that median DOR has not been reached, and 21 of those responders remain in CR.

Twenty-nine patients (54%) had treatment-related adverse events, the most common of which were pollakiuria, dysuria, and micturition urgency.

“TAR-200 monotherapy is associated with an unprecedented CR rate, durable responses, and a favorable tolerability profile in patients with BCG-unresponsive carcinoma in situ, supporting its continued investigation in HR NMIBC,” Dr. Necchi concluded.