A Prospective, Cohort Study of SITOIGANAP to Treat Glioblastoma When Given in Combination With Granulocyte-Macrophage Colony-Stimulating Factor/Cyclophosphamide/Bevacizumab/Nivolumab or Granulocyte-Macrophage Colony-Stimulating Factor/Cyclophosphamide/Bevacizumab/Pembrolizumab in Patients Who Failed Prior Treatment With Surgical Resection, Radiation, and Temozolomide

BackgroundGlioblastoma (GBM) is the most common primary, malignant brain tumor in adults and has a poor prognosis. The median progression-free survival (mPFS) of newly diagnosed GBM is approximately 6 months. The recurrence rate approaches 100%, and the case-fatality ratio approaches one. Half the patients die within 8 months of recurrence, and 5-year survival is less than 10%. Advances in treatment options are urgently needed. We report on the efficacy and safety of a therapeutic vaccine (SITOIGANAP: Epitopoietic Research Corporation) administered to 21 patients with recurrent GBM (rGBM) under a Right-to-Try/Expanded Access program. SITOIGANAP is composed of both autologous and allogeneic tumor cells and lysates. MethodsTwenty-one patients with rGBM received SITOIGANAP on 28-day cycles in combination with granulocyte-macrophage colony-stimulating factor (GM-CSF), cyclophosphamide, bevacizumab, and an anti-programmed cell death protein-1 (anti-PD-1) monoclonal antibody (either nivolumab or pembrolizumab). ResultsThe mPFS was 9.14 months, and the median overall survival (mOS) was 19.63 months from protocol entry. Currently, 14 patients (67%) are at least 6 months past their first SITOIGANAP cycle; 10 patients (48%) have received at least six cycles and have a mOS of 30.64 months and 1-year survival of 90%. The enrollment and end-of-study CD3(+)/CD4(+) T-lymphocyte counts strongly correlate with OS. ConclusionsThe addition of SITOIGANAP/GM-CSF/cyclophosphamide to bevacizumab and an anti-PD-1 monoclonal antibody resulted in a significant survival benefit compared to historic control values in rGBM with minimal toxicity compared to current therapy.

Automated summary

This study reports the efficacy and safety of the therapeutic vaccine SITOIGANAP in patients with recurrent glioblastoma (GBM). The results demonstrate that the addition of SITOIGANAP to existing therapy significantly extended patients' survival compared to historic control values, with minimal toxicity.