Phase II Study of Atezolizumab with Platinum and Etoposide Chemotherapy Followed by Cystectomy for Adults with Localized Small Cell Neuroendocrine Bladder Cancer

What this Trial Is About

Researchers are evaluating a combination treatment for patients with locally advanced small cell or neuroendocrine carcinoma of the bladder, with or without urothelial cancer. This Phase II trial aims to assess the pathologic complete response rate at the time of cystectomy, which is surgical removal of the bladder, after treatment with atezolizumab combined with platinum and etoposide chemotherapy. The study includes adults who are medically fit for chemotherapy, immunotherapy, and surgery. Participants will receive four cycles of combination therapy every 21 days, consisting of atezolizumab 1200 mg by intravenous infusion on Day 1, etoposide 100 mgm2 on Days 1 to 3, plus either carboplatin or cisplatin on Day 1. The choice between carboplatin and cisplatin can be adjusted by the investigator during treatment. After completing chemotherapy, patients will undergo cystectomy within 42 days. Following surgery, maintenance treatment with atezolizumab will continue every 21 days for up to one year or until unacceptable toxicity or loss of clinical benefit. During the study, participants will be closely monitored through regular clinical assessments, imaging, biochemical tests, and biopsy results when available. Researchers will measure the pathologic complete response at cystectomy and evaluate secondary outcomes such as safety and tolerability, disease progression, survival rates, and incidence of brain metastases up to five years. The total study duration extends until 2029, allowing for long-term follow-up and evaluation of treatment feasibility.

Atezolizumab Plus Etoposide and Platinum in Small Cell Bladder Cancer