Poster Session 7: Oncology – Bladder, Renal, Testes (Part 2)

Introduction: Patients (pts) with bacillus Calmette-Gurin (BCG)-unresponsive high-risk non-muscle-invasive bladder cancer (HR NMIBC) have a high risk of disease progression and limited treatment (tx) options.TAR-200 is an intravesical drug-releasing system designed to provide sustained delivery of gemcitabinein the bladder.SunRISe-1 (NCT04640623) is an ongoing phase 2b study assessing TAR-200 in pts with BCG-unresponsive HR NMIBC, ineligible for/refused radical cystectomy.Cohorts 1-3 enrolled pts with carcinoma in situ (CIS) papillary disease.We report one-year duration of response (DOR) and patient-reported outcomes (PRO) in pts receiving TAR-200 monotherapy (cohort 2).Methods: Pts (18 y; ECOG PS 0-2) had histologically confirmed CIS papillary disease (high-grade Ta, any T1) with last dose of adequate BCG 12 months of CIS diagnosis.TAR-200 was dosed Q3W to W24 then Q12W to W96.No re-induction for non-responders was allowed.Primary Endpoint was overall complete response (CR) rate.Secondary endpoints were DOR, overall survival, PROs, and safety.Response assessments included cystoscopy, centrally assessed urine cytology (Q12W), centrally assessed biopsy (W24/48), and local imaging (Q24W).Change from baseline in global health status (GHS) and physical functioning (PF) scores (0 [worse]-100 [better]) on EORTC-QLQ-C30, completed at W0, 6, 12, Q12W on tx, and at safety follow-up, was assessed.Results: On the September 4, 2024 data cutoff, 85 pts (median age, 71 y [range 40-88]; 80% male; 33% with concurrent papillary disease) received tx, wth a median followup 14 mo (range 2-41).Centrally confirmed and investigator-assessed CR rates were both 84% (95% CI 74-91).Estimated 12-month CR rate was 50% (95% CI 36-62).Estimated median DOR and one-year DOR rate were 26 months (95% CI 9-NE) and 55% (95% CI 40-68), respectively.Nine pts completed two years of tx; seven remain in response.Mean GHS (75 [SD 16.7]) and PF (86 [SD 17.3]) scores were high at baseline and stable on tx (did not exceed clinically meaningful change threshold of 10 points); 71 pts (84%) had tx-related adverse events (TRAEs); most were low-grade lower urinary tract AEs.Ten pts (12%) had grade 3 TRAEs; five (6%) had serious TRAEs; three (4%) had TRAEs leading to tx discontinuation.No tx-related deaths occurred.Conclusions: TAR-200 monotherapy was well-tolerated, with the highest CR rate reported in BCG-unresponsive HR NMIBC.Responses were highly durable, and most responders were disease-free at one year.Clinical benefit of TAR-200 was achieved with sustained overall health status and high PF.Data will be updated after final results in April.