Neoadjuvant Pembrolizumab Shows Promise for Cisplatin-Ineligible MIBC

Neoadjuvant pembrolizumab may improve pathologic response and survival in patients with cisplatin-ineligible muscle-invasive bladder cancer (MIBC) undergoing radical cystectomy, according to investigators presenting at American Society of Clinical Oncology’s 2023 Genitourinary Cancers Symposium in San Francisco, California.

Kyle M. Rose, MD, of H. Lee Moffitt Cancer Center in Tampa, Florida, and colleagues compared outcomes from 39 patients treated with neoadjuvant pembrolizumab from the PURE-01 trial and 313 patients who underwent immediate radical cystectomy. According to the PURE-01 trial protocol, the systemic therapy group received 3 cycles of pembrolizumab at a dose of 200 mg every 3 weeks prior to radical cystectomy.

Median overall survival was not reached in the neoadjuvant pembrolizumab compared with 19 months in the immediate surgery group, Dr Rose reported. In a propensity score matched analysis of 39 patients in each group, median overall survival again was not reach in the neoadjuvant pembrolizumab group compared with 21 months in the immediate surgery group. Overall survival rates significantly favored neoadjuvant pembrolizumab at 12 months (89% vs 57%), 24 months (64% vs 28%), and 36 months (33% vs 13%) after surgery. The immediate surgery group had a 2.0-fold increased risk of death compared with the neoadjuvant pembrolizumab group.

The neoadjuvant pembrolizumab group also had a significantly higher complete response rate on final pathology (pT0: 33% vs 13%). The baseline glomerular filtration rate was 51.0 mL/min/1.73 m² for both groups.

“Our results show promise in the neoadjuvant administration of immune-checkpoint inhibitors such as pembrolizumab in patients with muscle-invasive bladder cancer who are ineligible for cisplatin chemotherapy. Cisplatin-ineligible patients currently have no FDA-approved options,” Dr Rose said in an interview. “In our study, cisplatin-ineligible patients receiving neoadjuvant pembrolizumab had a higher rate of downstaging and a survival advantage over patients who underwent immediate radical cystectomy.”

He also stated, “Although this study suggests promising systemic options for cisplatin-ineligible patients in the neoadjuvant setting, results of ongoing prospective randomized trials will help validate these findings and provide therapeutic options to cisplatin-ineligible patients. A much-anticipated randomized control trial in this disease space includes the SWOG GAP trial (S2011), which compares combination gemcitabine, carboplatin, and avelumab vs no neoadjuvant therapy prior to upfront surgical therapy.”

Disclosure: Some study authors declared affiliations with biotech, pharmaceutical, and/or device companies. Please see the original reference for a full list of authors’ disclosures.

Reference

Rose KM, Bandini M, Huelster HL, et al. Neoadjuvant pembrolizumab for cisplatin-ineligible muscle-invasive bladder cancer prior to radical cystectomy. ASCO GU 2023, San Francisco, California, February 16-18. Abstract 513.

This article originally appeared on Renal and Urology News