Higher BMI, But Not Sarcopenia, Is Associated With Pembrolizumab-related Toxicity in Patients With Advanced Melanoma.

Background/aim To determine whether BMI and sarcopenia were related to treatment-limiting toxicity or efficacy of pembrolizumab treatment in melanoma patients. Patients and methods Medical records for melanoma patients undergoing pembrolizumab treatment at Duke University from January 2014 to September 2018 were reviewed. Pre-treatment measurements such as BMI were collected. Pre-treatment CT imaging was used to determine psoas muscle index (PMI). Patients in the lowest sex-specific tertile of PMI were sarcopenic. Logistic regression measured associations with treatment toxicity and response. Kaplan-Meier analysis assessed progression-free survival (PFS) and overall survival (OS). Results Among 156 patients, the overall objective response rate was 46.2% and 29 patients (18.6%) experienced treatment-limiting toxicity. Sarcopenia was not significantly associated with toxicity, response, or survival. However, obese patients (BMI >30) experienced higher rates of toxicity (p=0.0007). Conclusion Sarcopenia did not appear to predict clinically relevant outcomes. Obesity, however, represents a readily available predictor of pembrolizumab toxicity.