Role of perioperative immune checkpoint inhibitors in muscle invasive bladder cancer

Abstract

Objective To describe and highlight the current use of immune checkpoint inhibitors (ICIs) in the muscle-invasive bladder cancer (MIBC) treatment landscape, particularly focusing on the perioperative setting. We provide a comprehensive review of key trials of the use of ICI in the perioperative setting, discussing trial outcomes and limitations and reviewing the role of biomarkers. Background ICIs have recently been integrated into the treatment algorithm for metastatic urothelial carcinoma. Over 30 published studies have investigated the role of these agents in the radical treatment of MIBC. Some studies have demonstrated conflicting results, affecting widespread adoption in clinical practice. Methods We performed a narrative overview of the literature from databases including; PubMed, MEDLINE, Embase, European society of Medical Oncology/American Society of Clinical Oncology Annual Proceedings and clinicaltrials.gov databases up until December 2021. Discussion We described the results of key trials in the neoadjuvant and adjuvant setting and some of the reasons for conflicting study results, and the implications for clinical practice. Relevant biomarkers in the field are discussed, alongside a brief overview of the immune microenvironment in bladder cancer. Conclusion Perioperative ICIs have shown promising efficacy with low toxicity in the neoadjuvant setting. The two large trials in the adjuvant setting have been contradictory. The efficacy of perioperative ICIs combined with favorable tolerability and better toxicity profile compared to chemotherapy, with the potential for biomarker driven patient selection, may lead to a change in future practice. There is, however, a lack of long-term survival and toxicity data for those treated with ICIs , and this needs to be developed further to demonstrate an added survival benefit by using ICIs .