Sequential Immune Checkpoint Inhibition With Concurrent Bevacizumab For Relapsed Glioblastoma: A Single Centre Experience.

e13514Background: Median survival in relapsed glioblastoma is six months, and there are no established second-line therapies. There is increasing interest in the role of immunotherapy in glioblastoma but whilst immune checkpoint inhibitors are now routinely being used in other tumour types, the role of these drugs in glioblastoma is not yet formally evaluated. Methods: We retrospectively identified patients with glioblastoma treated with ipilimumab followed by pembrolizumab at progression, with concurrent bevacizumab and GM-CSF given throughout. Safety, tolerability and treatment responses were reviewed for all patients. Results: Four patients were identified: 3 male and 1 female aged between 23 and 55 years. All patients were treated for relapsed glioblastoma. All patients received 4 cycles of ipilimumab at first relapse, and subsequent pembrolizumab at second relapse (3 patients received 9 cycles, 1 patient received 10 cycles). One patient received concurrent lomustine chemotherapy and all patients rece...