Clinical activity of regorafenib in elderly patients with recurrent glioblastoma

Abstract

Glioblastoma multiforme is one of the most frequent and aggressive primary tumors in the central nervous system, representing >60% of all brain tumors in adults. Despite treatment, prognosis remains poor with most if not all patients experiencing disease recurrence and a 2-year survival rate of 27%. At present, no confirmed standard treatment exists for recurrent glioblastoma. Regorafenib is one of the few options available, based on results from the REGOMA trial. In the present study, a real-life retrospective investigation on the role of regorafenib in patients with recurrent glioblastoma (>60 years old) from two main Oncological Units in South Italy (Azienda Ospedaliera Universitaria Luigi Vanvitelli, Naples, Italy and Ospedale Civile San Giovanni di Dio, Frattamaggiore, Naples, Italy), was performed. The primary endpoint was overall survival (OS), whereas progression-free survival (PFS), objective response rate and disease control were secondary endpoints. Survival was then analyzed according to age, isocitrate dehydrogenase (IDH) and methylated methylguanine-DNA-methyltransferase (MGMT) status. A total of 56 patients met the eligibility criteria. The intention to treat population median PFS (mPFS) was 4.1 months and median OS (mOS) was 6.8 months. Age did not appear to have a significant influence on mPFS. mOS in MGMT-methylated patients was improved compared with that of the unmethylated group (7.7 months vs. 5.6 months). Both mOS and mPFS were longer in IDH-mutant patients. The present study was one of the first real life analyses of regorafenib in recurrent glioblastoma. The results were in line with the REGOMA trial. Age did not appear to be a prognostic factor, thus suggesting that treatment choice should not be different in elderly. MGMT methylation appeared to influence OS. To the best of our knowledge, this was the first report of regorafenib activity in older patients and, while the results were statistically significant, these should be confirmed in further studies.