A recent study presented at the 2024 International Bladder Cancer Network (IBCN) Annual Meeting has shed light on the response rates to additional Bacillus Calmette-Guérin (BCG) treatment in patients with non-muscle invasive bladder cancer (NMIBC). The research, led by Dr. Amanda Myers from MD Anderson Cancer Center, highlights the potential benefits of additional BCG in both BCG-exposed and BCG-unresponsive NMIBC cases, offering valuable insights for clinical trial design and patient management.
The study retrospectively analyzed 88 patients with high-grade NMIBC recurrences who received additional BCG as primary therapy. Among these, 52 were classified as BCG-exposed, and 36 as BCG-unresponsive according to FDA criteria. The primary outcome assessed was high-grade disease-free survival.
High Response Rates Observed
The results indicated that in BCG-exposed patients, treatment with additional BCG led to a complete response in 79% of cases, with a median duration of response of 169 months (95% CI 52 months - NR). In the BCG-unresponsive group, 75% of patients remained disease-free after additional BCG, with a median duration of response of 83 months (95% CI 35 - NR).
Two-year landmark analysis showed a disease-free survival rate of 63% (95% CI 51-78) for BCG-exposed patients and 63% (95% CI 48-81) for BCG-unresponsive patients.
Progression and Cystectomy-Free Survival
Furthermore, the study reported that at the 2-year landmark analysis, progression-free survival was 90% (95% CI 82-99) for BCG-exposed patients and 86% (95% CI 75-98) for BCG-unresponsive patients. The 2-year cystectomy-free rate was 82% (95% CI 72-93) in the BCG-exposed group. The 2-year overall survival rates were also high, at 96% (95% CI 91-100) for BCG-exposed and 91% (95% CI 83-100) for BCG-unresponsive patients.
Implications for Clinical Trials
Dr. Myers emphasized the importance of these findings for designing future clinical trials. Given the high response rates observed with additional BCG in BCG-exposed patients, she suggested that clinical trials in this population should compare new interventions against BCG as a control arm. This approach would provide a more accurate assessment of the added benefit of novel therapies.
The study's conclusion underscores the value of additional BCG in managing NMIBC, particularly in patients who have previously been exposed to BCG but have not met the strict criteria for BCG-unresponsiveness. The data serves as a benchmark for nonrandomized studies and can inform power calculations for randomized trials, potentially leading to more robust and meaningful clinical research in the field.
