P11.20.b association of hand-foot skin reactions with survival in recurrent glioblastoma patients treated with regorafenib

Abstract BACKGROUND The phase 2 REGOMA trial suggested a survival benefit of the multikinase inhibitor regorafenib for the treatment of patients with glioblastoma at first recurrence. Hand-foot skin reactions (HFSR) following multikinase inhibitor therapy have been reported as a predictor for prolonged survival in patients with solid tumors. Data on the predictive value of HFSR in patients with recurrent glioblastoma undergoing regorafenib therapy remain scarce. MATERIAL AND METHODS Fifty-seven patients (age range, 35-77 years) with recurrent IDH-wildtype glioblastomas were retrospectively identified from five centers in Germany and Switzerland. Regorafenib was administered at 160 mg/d for the first three weeks of each 4-week cycle, with individual dose adjustments according to toxicity. Patients were stratified into two groups based on the occurrence of HFSR following regorafenib. Group differences were investigated using the Mann-Whitney rank-sum test and Fisher's exact test. Kaplan-Meier analysis was used for univariate analyses, and the Cox proportional hazards regression model for multivariate analyses. RESULTS Patients received a median of two regorafenib cycles (range, 1-14 cycles). Median follow-up after recurrence was 7.0 months (range, 0.6-35.9 months). The median number of previous treatment lines was 2 (range, 1-6 lines). At the time of data analysis, 47 patients (82%) had died. HFSR were observed in 14 of 57 patients (25%) and was associated with a significantly longer OS (10.6 vs. 6.0 months; P=0.040). No significant group differences (HFSR compared to no HFSR) were observed regarding age, the extent of resection, MGMT promoter methylation, Karnofsky performance status, or number of completed regorafenib cycles (all P>0.05). Cox proportional hazards regression analysis confirmed that HFSR were associated with longer OS (P=0.039; HR, 0.438), independent of age, Karnofsky performance status, and the number of previous treatment lines (all P>0.05). CONCLUSION Our results suggest that the occurrence of HFSR following regorafenib is associated with longer OS in recurrent glioblastoma patients.