P2-01 TAR-200 IN PATIENTS WITH BACILLUS CALMETTE–GUÉRIN-UNRESPONSIVE HIGH-RISK NON–MUSCLE-INVASIVE BLADDER CANCER: RESULTS FROM SUNRISE-1 STUDY

Abstract

INTRODUCTION AND OBJECTIVE: Patients (pts) with Bacillus Calmettee Guérin (BCG)‐unresponsive high‐risk nonemuscle‐invasive bladder cancer (HR NMIBC) are at high risk of disease progression and have limited bladder‐sparing treatment (tx) options. TAR‐200, an intravesical drug delivery system, is designed to provide sustained release of gemcitabine in the bladder over 3 wks. SunRISe‐1 (NCT04640623) is an ongoing, randomized, phase 2b study assessing efficacy and safety of TAR‐200+cetrelimab (anti‐PD1) (Cohort 1 [C1]), TAR‐200 alone (C2), or cetrelimab alone (C3) in pts with BCGunresponsive HR NMIBC with carcinoma in situ (CIS), with or without papillary disease, who are ineligible for or refusing radical cystectomy. As of Amendment 4, TAR‐200 alone is also being assessed in pts with papillary disease only (C4). We report results from C2. METHODS: Eligible pts aged ≥18 yr had histologically confirmed carcinoma in situ (CIS)±papillary disease (high‐grade Ta, any T1) after adequate BCG, with last dose of BCG ≤12 mo prior to CIS diagnosis, and ECOG performance status 0‐2. TAR‐200 was dosed every 3 wks through Wk 24, then every 12 wks until Wk 96. Response was assessed by cystoscopy and centrally assessed urine cytology, CT/MRI, and bladder biopsy (at Wks 24, 48, and as clinically indicated). The primary end point was overall complete response (CR) rate. Secondary end points included duration of response (DOR), overall survival, safety, and tolerability. RESULTS: At data cutoff (Jan 2, 2024), 85 pts (median age, 71 yr; range, 40‐88; 33% with concurrent papillary disease) received TAR‐ 200 monotherapy. 58 pts were efficacy evaluable. Centrally confirmed CR rate was 83% (95% CI, 71‐91) by urine cytology and/or biopsy. The estimated 1 yr DOR rate is 75% (95% CI 50‐88), with median follow‐up in responders of 30 wks (range, 14‐140); 41 of 48 responders (85%) remain in CR at data cutoff. 47 of 48 (98%) of CRs were achieved at first disease assessment at wk 12. CR rate by investigator assessment (86%; 95% CI, 75‐94) correlated strongly with central results. 61 pts (72%) had tx‐related adverse events (TRAEs); most common (≥10%) were pollakiuria (35%), dysuria (29%), micturition urgency (15%), and urinary tract infection (15%). 7 pts (8%) had grade ≥3 TRAEs; 4 (5%) had serious TRAEs; 4 (5%) had TRAEs leading to discontinuation. No tx‐related deaths were reported. CONCLUSIONS: In SunRISe‐1, TAR‐200 monotherapy is associated with a clinically meaningful, high, centrally confirmed CR rate, durable responses, and a favorable benefit‐risk profile in pts with BCG‐unresponsive CIS.