Intravesical sequential gemcitabine and docetaxel versus bacillus calmette-guerin (BCG) plus interferon in patients with recurrent non-muscle invasive bladder cancer following a single induction course of BCG.

Introduction: Repeat BCG induction remains an option for select non-muscle invasive bladder cancer (NMIBC) patients who fail initial therapy. Alternative salvage intravesical regimens such as Gemcitabine and Docetaxel (Gem/Doce) have been investigated. We aimed to compare the efficacy BCG plus interferon a-2b (BCG/IFN) and Gem/Doce in patients with recurrent NMIBC after a single prior BCG course.

Methods: The National Phase II BCG/IFN trial database and multi-institutional Gem/Doce database were queried for patients with recurrent NMIBC after one prior BCG induction course, excluding those with BCG unresponsive disease. Stabilized inverse probability treatment weighted survival curves were estimated using the Kaplan-Meier method and compared. Propensity scores were derived from a logistic regression model. The primary outcome was recurrence free survival (RFS); secondary outcomes were high-grade (HG) RFS and risk factors for treatment failure.

Results: We identified 197 BCG/IFN and 93 Gem/Doce patients who met study criteria. Patients receiving Gem/Doce were older and more likely to have HG disease, CIS, and persistent disease following induction BCG (all P < 0.01). After propensity score-based weighting, the adjusted 1- and 2-year RFS was 61% and 53% after BCG/IFN versus 68% and 46% after Gem/Doce (P = 0.95). Adjusted 1- and 2-year HG-RFS was 60% and 51% after BCG/IFN versus 63% and 42% after Gem/Doce (P = 0.68). Multivariable Cox regression revealed that Gem/Doce treatment was not associated with an increased risk of failure (HR = 0.97, P = 0.89) as compared to BCG/IFN.

Conclusion: Patients with recurrent NMIBC after a single induction BCG failure and not deemed BCG unresponsive had similar oncologic outcomes with Gem/Doce and BCG/IFN in a post-hoc analysis. Additional prospective studies are needed.