CTNI-39. REGOMA-OS: A LARGE ITALIAN MULTICENTER, PROSPECTIVE, OBSERVATIONAL STUDY ANALYZING REGORAFENIB EFFICACY AND SAFETY IN RECURRENT GLIOBLASTOMA PATIENTS

Abstract BACKGROUND in the randomized phase 2 REGOMA trial, regorafenib (REG) showed promising activity in recurrent glioblastoma (GBM) patients (PTS); subsequently, in Italy the National Health System has permitted the reimbursement of the REG as second-line therapy. We performed a large multicenter, prospective and observational study to confirm REGOMA data in a real-world setting. Materials and METHODS major inclusion criteria were: histologically confirmed diagnosis of GBM according to WHO 2016 and relapse after Stupp treatment, good performance status (ECOG PS 0-1), good liver function. REG was administered at standard dose of 160mg/die for 3 weeks on/1 week off. Brain MRI was performed within 14 days before starting REG and every 8-12 weeks, subsequently. Primary endpoint was overall survival. RANO criteria were used for response evaluation, CTACAE v. 5 for adverse events. RESULTS from Sept 2020 to Oct 2022, 192 recurrent GBM PTS were enrolled from 29 Cancer Centres in Italy: median age was 58ys (IQR 52.8-67.0), 68% male, ECOG PS was 0 in 85 (44%), 115 PTS (60%) undertook steroids at baseline. MGMT was methylated in 43%, IDHwt in 92%. Median follow-up was 16.6 months (IQR 12.6-19.6). Median OS was 8.2ms (95% CI 6.5-9.6), 12ms-OS 34.7% (95%CI 27.2-42.4); median PFS was 2.6ms (95%CI 2.3-2.9), 6ms-PFS 14.3%. Radiological response was PR and SD in 12 (8%) and 25 (16%) PTS. 77 (44%) PTS received third-line therapy. The median of REG cycles per patient was 3 (IQR 2.0-4.0). Grade 3-4 adverse events (AE) were reported in 53 (28%) PTS; reduction/delay and permanent discontinuation due to AE in 36% and 8% of PTS. No death was considered as treatment-related AE. CONCLUSIONS compared to the REGOMA trial, this large Italian multicenter, prospective and observational trial confirmed the results in terms of overall survival with a good toxicity profile of REG in recurrent GBM PTS.