Phase II study of pembrolizumab plus SurVaxM for glioblastoma at first recurrence.

Abstract

TPS2581 Background: Glioblastoma is the most common primary malignant brain tumor with median survival of approximately 15-16 months. Following first recurrence, progression free survival at six months ~15%. There is no therapy in recurrent glioblastoma associated with any survival benefit and there is an urgent need for better therapeutic options. Immunotherapy is one promising option for patients with cancer. This is being explored in glioblastoma and a number of forms of active specific vaccination and immune checkpoint based approaches have been devised and are being investigated in glioblastoma. Methods: Pembrolizumab is a potent humanized immunoglobulin G4 (IgG4) monoclonal antibody (mAb) with high specificity of binding to the programmed cell death 1 (PD-1) receptor. Survivin is a 16.5 kDa intracellular protein that belongs to the inhibitor of apoptosis protein (IAP) family. SurVaxM is a 15 amino acid antigenic peptide that targets surviving capable of binding several human MHC class I molecules. Primary Objective is to assess clinical activity of Pembrolizumab and SurVaxM in patients with recurrent glioblastoma using progression free survival at 6 months (PFS-6) as determined using RANO criteria. Secondary Objective(s) includes safety and tolerability of combination, response rates, progression free survival and overall survival. Exploratory Objective include measuring cellular and humoral immune responses during concurrent administration of Pembrolizumab and SurVaxM. This is a phase II study of two arms in patients with recurrent glioblastoma. Arm A is patients with first recurrence of glioblastoma who have failed prior chemotherapy and radiation but have not received any immunotherapy. Arm B is an exploratory arm of glioblastoma patients who have failed prior anti-PD1 therapy. This clinical trial will enroll 41 patients with glioblastoma at first recurrence (bevacizumab naïve) in arm 1.This will include a 6-patient toxicity/safety run-in. There will an exploratory cohort of 10 patients who have failed prior PD1 blockade for a total of 51 patients in 2 arms. Key inclusion criteria include diagnosis of glioblastoma, Age ≥18 years old, Previous first line treatment with at least radiotherapy with or without temozolomide and Documented first recurrence of GBM and Karnofsky performance status of 70 and normal organ function. Key exclusion criteria include more than one recurrence of GBM, presence of extracranial metastatic or leptomeningeal disease, patients with > 1 cm midline shift on imaging. Patients must not require > 10 mg daily of prednisone equivalent. Clinical trial information: NCT04013672 .