Outcomes of maintenance BCG versus gemcitabine/docetaxel following BCG induction in NMIBC.

OBJECTIVES

To compare the oncologic outcomes and safety profiles of Bacillus Calmette-Guérin (BCG) versus gemcitabine/docetaxel (Gem/Doce) maintenance following BCG induction in treatment-naïve non-muscle-invasive bladder cancer (NMIBC).

METHODS

We identified patients with treatment-naive NMIBC who received induction BCG followed by maintenance BCG per the Southwest Oncology Group Cancer Research Network protocol or Gem/Doce monthly for 1 year (2016-2026). Oncological outcomes included recurrence-free survival (RFS), high-grade RFS, progression-free survival, and metastasis-free survival. Adverse events were systematically assessed to evaluate treatment tolerability.

RESULTS

Overall, 128 patients received BCG induction followed by either BCG maintenance (n = 98; 76.6%) or Gem/Doce maintenance (n = 30; 23.4%). After a median follow-up of 75.0 months (interquartile range [IQR] 66.7-86.5) in the BCG group and 22.5 months (IQR 14.8-42.9) in the Gem/Doce group (P < 0.001), 3-year RFS (80.0% vs. 83.8%; P = 0.8), 3-year high-grade RFS (83.4% vs. 92.2%; P = 0.7), 3-year progression-free survival (90.0% vs. 96.6%; P = 0.4), and 3-year metastasis-free survival (96.8% vs. 100.0%; P = 0.3) were comparable between the BCG and Gem/Doce maintenance groups, respectively. Multivariable Cox regression analysis confirmed that Gem/Doce versus BCG maintenance was not associated with disease recurrence (hazard ratio 1.04; 95% confidence interval 0.39-2.83; P > 0.9). Overall, Gem/Doce maintenance was better tolerated, with fewer patients reporting adverse events (6.7% vs. 28%, P = 0.02) and no severe events observed during the maintenance phase. Limitations of the study include its retrospective design and the relatively small sample size of the Gem/Doce cohort.

CONCLUSION

Sequential Gem/Doce maintenance following BCG induction achieved oncologic outcomes comparable to those with BCG maintenance, with improved tolerability, highlighting its feasibility as an alternative in cases of BCG intolerance or shortage.