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Sandy Srinivas, MD


ESMO 2023: Pembrolizumab Plus Enzalutamide Therapy Metastatic Prostate Cancer

By: Joshua D. Madera, MD
Posted: Tuesday, November 14, 2023

Efforts to identify novel adjunct therapies for patients with metastatic castration-resistant prostate carcinoma revealed that combination therapy with pembrolizumab and enzalutamide did not significantly improve clinical efficacy outcomes, according to the results of the KEYNOTE-641 study presented at the European Society for Medical Oncology (ESMO) Congress 2023 (Abstract 1771MO). This combination treatment strategy led to increased treatment-related adverse events for patients, explained Julie N. Graff, MD, of the VA Portland Healthcare System, Oregon, and colleagues.

From 2019 to 2022, a total of 1,244 patients with metastatic castration-resistant prostate carcinoma were recruited for the study. All participants had no history of chemotherapy except for the use of paclitaxel in the hormone-sensitive setting. Patients were stratified based on a history of treatment with abiraterone. In addition, they were randomly assigned to receive combination treatment with pembrolizumab and enzalutamide or a placebo with enzalutamide.

The study authors reported that the median radiographic progression–free survival was 10.4 months with pembrolizumab plus enzalutamide and 9.0 months with enzalutamide plus a placebo (hazard ratio [HR] = 0.98). In addition, the median overall survival was 24.7 months and 27.3 months, respectively, with and without pembrolizumab (HR = 1.04.). However, both dual primary endpoints were not met. Furthermore, grade 3 treatment-related adverse events were documented in 61.6% of patients treated with pembrolizumab plus enzalutamide and in 10.8% of patients treated with enzalutamide plus a placebo.

Disclosure: For full disclosures of the study authors, visit

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