Perioperative immune-based treatment for cisplatin-eligible muscle-invasive bladder cancer: a meta-analysis of...

Perioperative immune-based strategies are redefining the treatment landscape of muscle-invasive bladder cancer, but their overall benefit and subgroup effects remain incompletely characterized. The aim of this meta-analysis is to evaluate the efficacy and safety of perioperative immunotherapy-based strategies in cisplatin-eligible muscle-invasive bladder cancer and explore treatment effects across clinically relevant subgroups.

This is a systematic review and meta-analysis of randomized phase III trials assessing perioperative immune-based treatments in muscle-invasive bladder cancer. Hazard ratios for event-free survival and overall survival were pooled using random-effects models. Exploratory subgroup analyses were conducted by age, sex, race, and tumor stage. Safety outcomes were analyzed using risk ratios.

Two phase III trials were included. NIAGARA evaluated durvalumab added to cisplatin-based chemotherapy, whereas KEYNOTE-B15 evaluated enfortumab vedotin plus pembrolizumab as a chemotherapy-replacing strategy. The limited quantitative synthesis favored the experimental regimens for event-free survival (HR 0.61, 95% CI 0.48-0.78) and overall survival (HR 0.71, 95% CI 0.59-0.86). Benefit was observed across most subgroups. Numerically larger effects were observed in patients with higher-risk disease (>T2N0), whereas confidence intervals crossed unity in T2N0 disease; this finding is hypothesis-generating and does not establish a stage-treatment interaction. Overall toxicity incidence was similar between groups, although serious adverse events were more frequent in the experimental arms (RR 1.32, 95% CI 1.18-1.49). Differences in treatment exposure and regimen-specific toxicity limit interpretation of a uniform class effect. Limitations include the small number of trials and exploratory subgroup analyses.

Available randomized evidence supports the clinical integration of the specific perioperative immune-based regimens evaluated in NIAGARA and KEYNOTE-B15 for cisplatin-eligible muscle-invasive bladder cancer. However, the two regimens should not be considered interchangeable, and the optimal regimen and patients deriving the greatest benefit remain uncertain.