GU Symposium 2021: Neoadjuvant Gemcitabine, Cisplatin, and Pembrolizumab in Bladder Cancer
Posted: Monday, March 8, 2021
Among patients with muscle-invasive bladder cancer, neoadjuvant therapy with gemcitabine, spit-dose cisplatin, and pembrolizumab appears to be generally safe and improved pathologic downstaging. Tracy L. Rose, MD, of the University of North Carolina at Chapel Hill School of Medicine, and colleagues shared these findings during the virtual 2021 Genitourinary (GU) Cancers Symposium (Abstract 396).
This phase II study enrolled 39 patients with clinical stage T2–4a N0 M0 muscle-invasive urothelial carcinoma of the bladder who were eligible for radical cystectomy. Patients were treated with 200 mg of pembrolizumab, 35 mg/m2 of cisplatin, and 100 mg/m2 of gemcitabine on day 1, followed by 35 mg/m2 of cisplatin and 100 mg/m2 of gemcitabine on day 8, every 3 weeks for a median of 4 cycles. Approximately 4 to 8 weeks after completion of neoadjuvant therapy, patients underwent radical cystectomy.
Patients within the study population had the following tumor stages prior to therapy: 72% had T2 disease, 23% had T3 disease, and 5% had T4 disease. The population was 82% male, with an average age of 66. The rate of tumor downstaging, defined as stage T2 N0 at the time of cystectomy, was 56%, and the T0 N0 rate was 36%. Survival data are not yet mature.
The most common adverse event of any grade was thrombocytopenia (74%), followed by anemia (69%), neutropenia (67%), and hypomagnesemia (67%). Common grade 3 or 4 adverse events included neutropenia (41%), thrombocytopenia (33%), febrile neutropenia (13%), and anemia (10%). One study participant developed new-onset type 1 diabetes mellitus with ketoacidosis, apparently due to pembrolizumab therapy; however, no patients required steroids for immune-related adverse events. Nine patients (23%) discontinued gemcitabine, cisplatin, and pembrolizumab therapy because of adverse events.
Disclosure: For a full list of authors’ disclosures, visit coi.asco.org.