Low Body Weight as a Risk Factor for Apalutamide-related Cutaneous Adverse Events

Therapeutic strategies for prostate cancer are currently undergoing a paradigm shift due to the advent of next-generation androgen receptor inhibitors. Among these inhibitors, apalutamide is regarded as a key drug because of its effectiveness. However, risk factors for and the timing of the onset of apalutamide-related cutaneous adverse events remain unclear. Therefore, the present study investigated key risk factors for and timing of the onset of apalutamide-related cutaneous adverse events.Sixty-two Japanese patients with non-metastatic castration-resistant prostate cancer treated with 240 mg/day of apalutamide were enrolled in the present study.Twenty-four patients (38.7%) developed cutaneous adverse events. Multivariable logistic regression analysis of age, height, and body weight identified body weight as a significant predictive factor for the incidence of cutaneous adverse events (p=0.019). When the mean body weight of patients (63.80 kg) was set as the cut-off value, the Kaplan-Meier analysis revealed that the risk of cutaneous adverse events was significantly increased in those with a body weight63.8 kg (p=0.003, the log-rank test). The analysis also showed that cutaneous adverse events developed within the first 6 months regardless of body weight.A lower body weight is a significant risk factor for apalutamide-related cutaneous adverse events and their onset is within 6 months of initiation of therapy.