Immune checkpoint inhibitor therapy for recurrent meningiomas: a retrospective chart review

Meningiomas that progress despite surgery and radiotherapy represent an unmet medical need. Expression of PD-1 and PDL-1 has been demonstrated in meningiomas and is proportional to tumor grade, suggesting a potential role for anti-PD-1/anti-PDL-1 inhibitor therapy. We explored the potential role of immunotherapy for recurrent meningiomas by describing progression-free survival (PFS) and overall survival (OS) in a single-center patient sample.This is a retrospective chart review of patients with meningioma who were treated with PD-1 inhibitors at UPMC Hillman Cancer Center. Any patient over age 18 who received immunotherapy was included in this study. Patients received treatment until development of disease progression, intolerable toxicities or adverse events, death, or oncologist decision. Serial radiographic assessments were made every 3-6 months.Between January 2015 and November 2021, eight patients received anti-PD-1 therapy. All patients underwent tumor resection and radiosurgery, and four patients received prior systemic therapy. Six out of eight patients experienced symptomatic perilesional edema and three patients experienced exacerbation of seizures. Median PFS was 7 months (95% CI 1-24) and median OS was 1.75 years (95% CI 1.5-4.0). In patients with positive PD-1/PD-L1 expression, median PFS was 2 years and median OS was 3 years.Anti-PD-1 therapy was associated with a manageable safety profile in patients with recurrent meningiomas. Patients with WHO Grade III tumors and positive PD-1/PD-L1 expression were noted to have increased PFS and OS, suggesting a potential role for immunotherapy in these patients, but further studies are needed to investigate this in a larger patient population.