A Phase 1b/2 Study of Atezolizumab with or Without Bacille Calmette-Guérin in Patients with High-risk Non-muscle-invasive Bladder Cancer

Brant A. Inman, Noah M. Hahn, Kelly Stratton, Ryan Kopp, Alex Sankin, Eila Skinner, Kamal Pohar, Benjamin A. Gartrell, Song Pham, Deepali Rishipathak, Sanjeev Mariathasan, Nicole Davarpanah, Corey Carter, Gary D. Steinberg

Research output: Contribution to journalArticlepeer-review

Abstract

BACKGROUND: Bacille Calmette-Guérin (BCG) is the standard therapy after transurethral resection of bladder tumour for high-risk non-muscle-invasive bladder cancer (NMIBC). However, post-BCG recurrence/progression occurs frequently, and noncystectomy options are limited. OBJECTIVE: To evaluate the safety and clinical activity of atezolizumab ± BCG in high-risk BCG-unresponsive NMIBC. DESIGN, SETTING, AND PARTICIPANTS: This phase 1b/2 GU-123 study (NCT02792192) treated patients with BCG-unresponsive NMIBC who had carcinoma in situ with atezolizumab ± BCG. INTERVENTION: Patients in cohorts 1A and 1B received atezolizumab 1200 mg IV q3w for ≤96 wk. Those in cohort 1B also received standard BCG induction (six weekly doses) and maintenance courses (three doses weekly starting at month 3) with optional maintenance at 6, 12, 18, 24, and 30 mo. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: Coprimary endpoints were safety and 6-mo complete response (CR) rate. Secondary endpoints included 3-mo CR rate and duration of CR; 95% confidence intervals were calculated using the Clopper-Pearson method. RESULTS AND LIMITATIONS: At data cut-off (September 29, 2020), 24 patients were enrolled (cohort 1A, n = 12; cohort 1B, n = 12), and the recommended BCG dose was 50 mg in cohort 1B. Four patients (33%) had adverse events (AEs) leading to BCG dose modification/interruption. Three patients (25%) in cohort 1A reported atezolizumab-related grade 3 AEs; cohort 1B had no atezolizumab- or BCG-related grade ≥3 AEs. No grade 4/5 AEs were reported. The 6-mo CR rate was 33% in cohort 1A (median duration of CR, 6.8 mo) and 42% in cohort 1B (median duration of CR, not reached [≥12 mo]). These results are limited by the small sample size of GU-123. CONCLUSIONS: In this first report of the atezolizumab-BCG combination in NMIBC, atezolizumab ± BCG was well tolerated, with no new safety signals or treatment-related deaths. Preliminary results suggested clinically meaningful activity; the combination favoured a longer duration of response. PATIENT SUMMARY: We studied atezolizumab with and without bacille Calmette-Guérin (BCG) to determine whether this combination was safe and had clinical activity in patients with high-risk noninvasive bladder cancer (high-grade bladder tumours that affect the outermost lining of the bladder wall) that has previously been treated with BCG and is still present or occurred again. Our results suggest that atezolizumab with or without BCG was generally safe and could be used to treat patients unresponsive to BCG.

Original languageEnglish (US)
Pages (from-to)313-320
Number of pages8
JournalEuropean Urology Oncology
Volume6
Issue number3
DOIs
StatePublished - Jun 1 2023

Keywords

  • Atezolizumab
  • BCG unresponsive
  • Bacille Calmette-Guérin
  • Carcinoma in situ
  • Non–muscle-invasive bladder cancer

ASJC Scopus subject areas

  • General Medicine

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