2019 GU Symposium: Nivolumab Plus Ipilimumab in Metastatic Castration-Resistant Prostate Cancer
Posted: Friday, February 22, 2019
According to the CheckMate 650 trial, some men with “immunologically cold” prostate cancer may respond to combination therapy with immune checkpoint inhibitors. In reportedly the first trial two immunotherapies in prostate cancer, led by Padmanee Sharma, MD, PhD, of The University of Texas MD Anderson Center, and colleagues, treatment with nivolumab and ipilimumab demonstrated activity in patients with advanced metastatic castration-resistant prostate cancer. Findings from this study were presented at the 2019 Genitourinary Cancers Symposium in San Francisco (Abstract 142).
“These results support the idea that immune checkpoint blockade can play an important role in the treatment of these patients and provide the foundation to test this strategy in a larger clinical trial,” stated Dr. Sharma in an institutional press release.
In this phase II, multicenter, open-label study, men with metastatic castration-resistant prostate cancer were treated with nivolumab and ipilimumab, stratified according to disease progression after hormone therapy alone (cohort 1) or hormone therapy and chemotherapy (cohort 2). Of the 78 patients with adequate follow-up (at least 6 months), 62 patients had measurable tumors. Of these 62 men, decreased tumor size was seen in 25% in cohort 1 and 10% of patients in cohort 2. In both cohorts, PD-L1 expression of at least 1%, DNA damage repair, and a high tumor mutational burden were associated with higher response rates.
The rate of treatment-related adverse effects in this trial was comparable to that reported in other combination trials. Grade 3 to 5 adverse events were reported in 42% of patients in cohort 1 and 53% of patients in cohort 2. Four deaths (2 in each cohort) were reported.