Phase 2 Study of Gemcitabine and Cisplatin With Cemiplimab, With or Without Fianlimab, for Treating Localized Muscle-Invasive Bladder Cancer

What this Trial Is About

Researchers are evaluating whether combining gemcitabine, cisplatin, and cemiplimab with or without fianlimab can treat adults with localized muscle-invasive bladder cancer. This phase 2, open-label, randomized trial aims to determine if these drug combinations can improve organ preservation in this condition while monitoring safety using Bayesian toxicity methods. Participants will be randomly assigned to receive either gemcitabine, cisplatin, and cemiplimab or the same combination with added fianlimab. Treatment includes 4 cycles of chemotherapy and immunotherapy over 12 weeks, followed by a repeat bladder tumor resection and imaging. Those showing a complete response continue maintenance immunotherapy for 13 additional cycles, totaling 52 weeks of systemic treatment including neoadjuvant and adjuvant phases, with recovery periods between treatments. Throughout the study, participants will have regular visits for safety and response assessments including lab tests, vital signs, physical exams, cystoscopy, urine cytology, and imaging scans every three months to check for disease spread or recurrence. The main outcome measured is clinical complete response at 16 weeks, with additional monitoring of adverse events, bladder-intact survival, recurrence-free survival, and overall survival for up to five years.

Gemcitabine/Cisplatin Plus Cemiplimab With or Without Fianlimab in Localized Muscle-invasive Bladder Cancer (NeoSTOP-IT)