Pembrolizumab Utilization and Clinical Outcomes Among Patients With Advanced Melanoma in the US Community Oncology Setting: An Updated Analysis

Favorable outcomes have been observed with pembrolizumab among patients with advanced melanoma in clinical trials; however, limited evidence exists on the long-term efficacy in the real-world setting. This was an updated, retrospective observational study of adult patients with advanced (unresectable or metastatic) melanoma who initiated pembrolizumab (in any line of therapy) between January 1, 2014, and December 31, 2016, in The US Oncology Network and were followed through December 31, 2019 [median follow-up: 18.2 mo (range: 0.1-63.1 mo)]. Study data were sourced from electronic health records. Patient demographic, clinical, and treatment characteristics were assessed descriptively. Kaplan-Meier methods were used to evaluate overall survival (OS), time to treatment discontinuation, time to next treatment, physician-assessed time to tumor progression, and physician-assessed progression-free survival (rwPFS). Independent risk factors for OS and rwPFS were identified with multivariable Cox regression models. Of the 303 study-eligible patients, 119, 131, and 53 received pembrolizumab in the first-line, second-line, and third-line or beyond setting, respectively. Median OS across the study population was 29.3 months [95% confidence interval (CI): 20.3-49.7] and was the longest among those who received first-line pembrolizumab [42.8 mo (95% CI: 24.8-not reached)]. Median rwPFS across the study population was 5.1 months (95% CI: 4.0-7.6) and 8.1 months (95% CI: 4.6-14.4) among those who received first-line pembrolizumab. In the multivariable analyses for OS, increased age, worsening performance status, elevated lactate dehydrogenase, brain metastases, and pembrolizumab use in later lines were significantly associated a worse prognosis.