The U.S. Food and Drug Administration (FDA) has granted Breakthrough Therapy Designation to TAR-200, an investigational intravesical delivery system developed by Johnson & Johnson, for the treatment of patients with Bacillus Calmette-Guérin (BCG)-unresponsive, high-risk non-muscle-invasive bladder cancer (NMIBC) who are ineligible for or have elected not to undergo radical cystectomy. This designation aims to expedite the development and regulatory review of TAR-200, acknowledging its potential to offer a substantial improvement over existing therapies. The decision is supported by preliminary clinical evidence from the Phase 2b SunRISe-1 trial.
Promising Results from SunRISe-1 Trial
The Breakthrough Therapy Designation was informed by data from the Phase 2b SUNRISE-1 trial (NCT04640623), an open-label study evaluating the safety and efficacy of TAR-200. The trial's cohort 2, focusing on TAR-200 monotherapy, demonstrated a complete response (CR) rate of 76.7% (95% CI, 57.7-90.1) per central review, with 23 out of 30 evaluable patients achieving CR. Investigator-assessed CR rate was 80.0% (95% CI, 61.4-92.3; 24 of 30 patients).
At a median follow-up of 48 weeks (range, 12-121), 21 (91%) of the 23 CRs remained ongoing, and the median duration of response (DOR) was not reached. Eleven complete responders had a DOR of at least 6 months (10 of 11 ongoing), and 6 had a DOR of at least 12 months (all ongoing). None of the complete responders required radical cystectomy at the time of analysis.
TAR-200: A Novel Approach to Bladder Cancer Treatment
TAR-200 is an investigational targeted releasing system designed for the controlled release of gemcitabine directly into the bladder, sustaining local drug exposure for several weeks. This intravesical delivery system offers a novel interventional approach for localized bladder cancer, addressing the limitations of current options such as BCG therapy and radical cystectomy.
Ongoing Clinical Trials
Beyond the SunRISe-1 trial, TAR-200 is currently being evaluated in several other clinical trials, including:
- SUNRISE-2 (NCT04658862): Evaluating TAR-200 in patients with muscle-invasive bladder cancer (MIBC) who are ineligible for or refuse radical cystectomy.
- SUNRISE-3 (NCT05714202): Assessing TAR-200 in patients with BCG-naive high-risk NMIBC.
- SUNRISE-4 (NCT04919512): Investigating TAR-200 in the neoadjuvant MIBC setting.
Safety Profile
The safety analysis from the SunRISe-1 trial included 54 patients. Most adverse events (AEs) were grade ≤2. Over half (53.7%) of patients experienced at least one treatment-related AE (TRAE), and 7.4% had at least one grade ≥3 TRAE. Discontinuations due to TRAEs occurred in 2 patients, and no patient deaths were reported during the trial.
Cetrelimab
Cetrelimab is an investigational programmed cell death receptor-1 (PD-1) monoclonal antibody being studied for the treatment of bladder cancer, prostate cancer, melanoma, and multiple myeloma as part of a combination regimen.
High-Risk Non-Muscle-Invasive Bladder Cancer
High-risk non-muscle-invasive bladder cancer (HR-NMIBC) makes up 15–44 percent of patients with NMIBC and is characterized by a high-grade, large tumor size, presence of multiple tumors and CIS. Radical cystectomy is currently recommended for NMIBC patients who are unresponsive to BCG therapy, with over 90 percent cancer-specific survival if performed before muscle-invasive progression. Given that NMIBC typically affects older patients, many may be unwilling or unable to undergo radical cystectomy. The high rates of recurrence and progression can pose significant morbidity and distress for patients with NMIBC.
