Inovio Pharmaceuticals announced positive interim results from a phase 2 study in patients with newly diagnosed glioblastoma multiforme (GBM) evaluating a combination of Inovio’s INO-5401, a T cell-activating immunotherapy encoding for three tumor-associated antigens, and INO-9012, an immune activator encoding IL-12, in combination with Libtayo (cemiplimab), a PD-1 blocking antibody developed by Regeneron Pharmaceuticals in collaboration with Sanofi. The data will be featured in a late-breaking poster presentation at the Society for Immunotherapy of Cancer (SITC) 2019 Annual Meeting in National Harbor, Maryland, November 6-10.
The phase 1/2 study was an open-label, multi-center design in 52 evaluable patients with GBM. There were 2 cohorts in this trial. Cohort A were patients with a tumor with an unmethylated O6-methylguanine-deoxyribonucleic acid (DNA) methyltransferase (MGMT) promoter. Cohort B included patients with a tumor with an MGMT methylated promoter or who have indeterminate MGMT status. Both cohorts received INO-5401 and INO-9012 and Libtayo at the same doses and on the same dosing schedule, and both cohorts received radiation and temozolomide (TMZ) if clinically indicated. Interim data are as of October 2019 and final study data is expected in Q4 2020.
Key interim data showed that 80% (16 of 20) of MGMT gene promoter methylated patients and 75% (24 of 32) of unmethylated patients were progression-free at six months (PFS6) measured from the time of their first dose, substantially exceeding historical standard-of-care data. This immunotherapy combination also exhibited supportive safety, tolerability, and immunogenicity data and suggested an acceptable safety profile consistent with that of Libtayo and Inovio’s platform technology. The majority of patients tested had a T cell immune response to one or more tumor-associated antigens encoded by INO-5401. Immune responses to all three tumor-associated antigens were demonstrated in this study.