As recently as 2016, when a patient with advanced bladder cancer was too medically frail to take the standard-of-care chemotherapy agent cisplatin, oncologists had no effective alternatives to offer. By harnessing the immune system to target bladder cancer, researchers have yielded two discrete new treatment agents.
Based primarily on clinical trials led by Arjun V. Balar, MD, assistant professor of medicine and director of the Genitourinary Medical Oncology Program at Perlmutter Cancer Center, the FDA in early 2017 approved atezolizumab (Tecentriq®) and pembrolizumab (Keytruda®) as first-line treatments for these particularly frail patients with advanced bladder cancer. These immune system–boosting agents are the first-ever FDA-approved treatments for cisplatin-ineligible bladder cancer.
In the clinical evaluation of atezolizumab, published in The Lancet in January 2017, bladder tumors shrank by at least 30 percent and new tumor growth stalled in 28 (24 percent) of 119 patients. All study participants received the medication as their initial therapy for the disease. Similarly, pembrolizumab shrank tumors by at least a third in 24 percent of patients. Of those, 6 percent saw their tumor lesions disappear. The pembrolizumab study was published in The Lancet Oncology in November 2017. All patients enrolled in the study were ineligible for cisplatin because of medical frailty.
“Responses with non-cisplatin chemotherapy, the previous standard, are short-lived, and patients die within 10 months, on average,” says Dr. Balar.
“Immunotherapy harnesses the immune system to generate durable responses and is better tolerated than chemotherapy. Immunotherapy is the most important advance in bladder cancer therapy in more than 30 years, and it has charted a new path in how we will approach understanding and treating this cancer moving forward.”