BMI associated with pembrolizumab treatment toxicity

Baseline characteristics such as albumin, creatinine and BMI are useful biomarkers to aid in the management of patients with melanoma who are undergoing pembrolizumab treatment.

“Factors predicting the efficacy and toxicity of pembrolizumab in this patient population remain incompletely defined. Some studies have emerged suggesting ... higher BMI is associated with overall better survival in this patient population treated with immunotherapy,” Surya Ravichandran, BS, Duke University School of Medicine, said at the American Academy of Dermatology virtual meeting. “We sought to determine whether simple measures such as body mass index and sarcopenia ... can help us predict toxicity and efficacy of pembrolizumab and the treatment of melanoma.”

Baseline characteristics, treatment outcomes and survival data were reviewed in a retrospective study, which included 156 patients who underwent pembrolizumab treatment at Duke University Hospital from January 2014 to September 2018. CT imaging was used to determine psoas cross-sectional area and density, and patients were then divided in tertiles defined by weight. Patients in the lowest sex-specific tertile of psoas area were categorized as sarcopenic, and patients in the lowest sex-specific tertile of density were categorized as density-sarcopenic.

The study found BMI was statistically associated with toxicity (P = .0004), with patients with obesity showing higher rates of treatment-ending toxicity (35% in patients categorized vs. 7% and 12% for patients categorized as overweight and low to average BMI, respectively). Patients did not differ in rates of objective response, progression-free or overall survival based on BMI. Additionally, no differences in toxicity were found based on sarcopenic status.

“While sarcopenia was not predictive of efficacy or toxicity associated with pembrolizumab treatment in the patients with advanced melanoma, higher BMI, which is a routinely measured and readily available baseline patient characteristic, was associated with treatment toxicity,” Ravichandran said. “Therefore, we believe the knowledge that patients with higher BMI are at a higher risk of toxicity may help us inform clinical decision-making and provide incentives anticipatory guidance.”