Massimiliano Domenico Rizzaro, Claudia Fanizzi, Giorgio Fiore, Luigi Gianmaria Remore, Guido Del Vecchio, Elena Scagliotti, Giovanni Pratelli, Stefano Borsa, Stefania Elena Navone, Ilaria Bertorelli, Luca Enrico Sironi, Gabriella Roda, Giovanni Marfia, Manuela Caroli, Marco Locatelli
In this retrospective single-center cohort, reduced-dose regorafenib was feasible and well tolerated in selected patients. These descriptive, hypothesis-generating findings warrant prospective studies to define the role of individualized regorafenib dosing in recurrent glioblastoma.
BACKGROUND/OBJECTIVES: Recurrent glioblastoma has a poor prognosis and no universally accepted standard of care. Regorafenib has been investigated in this setting, but its use may be limited by treatment-related toxicity. This study evaluated the feasibility, safety, and clinical outcomes of reduced-dose regorafenib in patients with recurrent IDH-wildtype glioblastoma.
METHODS: We retrospectively analyzed 21 patients with recurrent IDH-wildtype glioblastoma (WHO 2021) treated at a single center after progression according to the Stupp protocol. Regorafenib was started at 80 mg/day on the standard 3-weeks-on/1-week-off schedule. We assessed overall survival from diagnosis (OS1) and from first progression (OS2), progression-free survival from diagnosis (PFS1) and from first progression (PFS2), treatment exposure, dose modifications, and treatment-related adverse events (CTCAE v5.0).
RESULTS: Median PFS2 was 5 months (95% CI, 3-8), median OS2 was 6 months (95% CI, 5-10), and median OS1 was 21 months (95% CI, 15-27). No grade ≥ 3 adverse events occurred, and no patient discontinued treatment permanently because of toxicity.
CONCLUSIONS: In this retrospective single-center cohort, reduced-dose regorafenib was feasible and well tolerated in selected patients. These descriptive, hypothesis-generating findings warrant prospective studies to define the role of individualized regorafenib dosing in recurrent glioblastoma.