Muscle invasive bladder cancer (MIBC) is difficult to manage for patients who progress during or after initial chemotherapy regimens. Current regimens offer low response rates with high toxicities. The advent of immune checkpoint inhibitors may represent a new opportunity for effective management of these patients. Areas covered: Atezolizumab is an engineered humanized monoclonal immunoglobulin G1 antibody that binds selectively to PD-L1 and prevents its interaction with PD-1 and B7-1. It is administered intravenously and is given every 3 weeks as long as there is no evidence of tumor progression. Phase I trials confirmed anti-tumor activity of atezolizumab in patients with advanced or metastatic urothelial carcinoma. Phase II trials show an improved response rate and a longer durable response than current conventional therapy. Phase III trials are currently underway with an estimated accrual end date of 2017. Expert Opinion: MIBC is a high-risk disease and after progression on current chemotherapy regimens, second-line treatments leave much to be desired. Emerging evidence of efficacy and safety, and a recent accelerated approval by the FDA presents atezolizumab as a promising treatment option. Current clinical challenges include the details of disease progression and determining where immune checkpoint inhibition will reside in the treatment algorithm.
Expert opinion on drug metabolism & toxicology. 2017 Jan 03 [Epub ahead of print]
Rutveej Patel, Megan Bock, Charles F Polotti, Sammy Elsamra
a Division of Urology , Rutgers Robert Wood Johnson Medical School , New Brunswick , New Jersey , USA.