Incidence and risk factors for dermatologic adverse events following apalutamide use: a real-world data analysis in the Korean population.

Purpose: This study aimed to assess the incidence, severity, and onset of dermatologic adverse events (dAEs) in Korean patients treated with apalutamide for metastatic hormone-sensitive prostate cancer (mHSPC) and to identify clinical and laboratory predisposing factors. Materials and methods: We retrospectively analyzed data of patients treated with apalutamide for mHSPC at a tertiary referral center in Korea between April 2023 and March 2024. Patients with a radical prostatectomy history or insufficient data were excluded. The onset, severity, and management of dAEs were evaluated and compared between patients with and without dAEs. Clinical and laboratory data from 1 month prior to apalutamide administration were collected. Logistic regression was performed to identify predictors of dAEs, and the predictive value of serum albumin levels was analyzed using the receiver operating characteristic (ROC) curve. Results: Twenty-six (40.0%) of the 65 patients developed dAEs, including nine (13.8%) with Grade ≥3 events. The median onset of dAEs was 66.5 (45-78) days. Patients with dAEs had significantly lower initial prostate-specific antigen levels (70.4 vs. 301.6 ng/mL), higher Eastern Cooperative Oncology Group Performance Status (ECOG-PS; 30.8% vs. 5.1%), and lower serum albumin levels (3.8 vs. 4.1 g/dL). Logistic regression identified elevated Eastern Cooperative Oncology Group-Performance Status (ECOG-PS) and hypoalbuminemia as significant predictors of dAEs. ROC analysis for serum albumin levels produced an area under the curve of 0.739, with a cutoff value of 3.85 g/dL, yielding a sensitivity and specificity of 65.4% and 74.4%, respectively. Conclusion: dAEs are prevalent in Korean patients treated with apalutamide for mHSPC, with ECOG-PS and serum albumin levels identified as significant risk factors.