Bacillus Calmette-Guérin (BCG) treatment patterns and real-world outcomes in high-risk (HR) non-muscle-invasive bladder cancer (NMIBC): A systematic literature review (SLR).

Abstract

730 Background: Transurethral resection followed by induction and maintenance intravesical BCG is currently standard of care for patients with HR NMIBC. HR is generally defined as stage T1, high grade (HG), carcinoma in situ, tumors >3 cm, variant histology, BCG failure in HG tumor, or lymphovascular invasion. Considering the variability in HR definitions and BCG maintenance schedules, we analyzed the evidence on maintenance utilization and outcomes in patients with HR NMIBC. Methods: We conducted an SLR of English-language real-world evidence (RWE) studies published 01/01/2011–06/12/2024 reporting efficacy or safety outcomes with BCG in patients with HR NMIBC using MEDLINE, Embase, and Cochrane supplemented by manual searches of relevant conference proceedings 2021–2024. Studies reporting treatment patterns or progression-/recurrence-related outcomes were analyzed. Results: Among 244 RWE studies identified, 86 reported data on HR populations, which was defined by commonly accepted definitions such as T1 high grade (HG) or any HG, with 37.2% using AUA/EAU guidelines. Across studies reporting BCG maintenance patterns in the HR population, 40.7% of patients (6,795/16,712; 16 studies) received some form of maintenance. Details on maintenance duration were reported in 11 studies; among them, 27.9% of patients (1,154/4,142) completed ≥1 year of maintenance. Details on adequate BCG treatment were reported in 8 studies, defined as receipt of ≥5/6 induction instillations and ≥2/3 maintenance instillations. Across these eight studies, 59.5% of patients (10,122/17,007) did not receive adequate BCG treatment. While comparisons across studies should be interpreted with caution due to heterogeneity in study populations. Median 2-year recurrence-free survival (RFS), 5-year RFS, and 2-year progression-free survival (PFS) across studies was numerically longer with maintenance versus induction alone (table). However, median 5-year PFS across studies appeared similar with or without maintenance. Conclusions: Less than 50% of HR patients who started BCG treatment received some form of maintenance; however, studies were highly heterogenous in reporting patterns of BCG treatment and definitions of HR NMIBC. Although maintenance duration was underreported, ~30% of patients completed ≥1 year of maintenance. In patients with HR NMIBC, RWE suggests improved outcomes with maintenance versus induction alone. More studies are needed to confirm the benefit of different maintenance schedules and durations. Real-world efficacy outcomes: HR NMIBC population. Induction, median (range) [n studies], % Induction + maintenance, median (range) [n studies], % 2-year PFS 85.7 (81–95) [3] 92.0 (89–98) [8] 2-year RFS 66.7 (53–81) [2] 77.1 (62–85) [7] 5-year PFS 82.6 (72–89) [4] 84.0 (53–98) [13] 5-year RFS 53.0 (31–75) [6] 64.7 (27–78) [10]