Celldex Therapeutics, Inc. (NASDAQ: CLDX) announced today that its immunotherapeutic vaccine called Rindopepimut showed positive results in prolonging survival in patients with newly diagnosed EGFRvIII-positive glioblastoma (GB), one of the most aggressive forms of brain cancer. 65 patients in 31 locations were choosen for the study known as ACT III
The overall historic survival rate for patients with GB selected to match those on the trial was 15.2 months. Rindopepimut targets the tumor-specific molecule, epidermal growth factor receptor variant III (EGFRvIII). EGFRvIII is a mutated form of the epidermal growth factor receptor (EGFR) that is only expressed in cancer cells and not in normal tissue, and is a transforming oncogene that can directly contribute to cancer cell growth.
Expression of EGFRvIII is linked to poor long term survival, regardless of other factors, such as extent of resection and age. EGFRvIII has been expressed in 31% of GB tumors when assessed using the Celldex PCR assay.
31 locations participated in the study and results are very consistent with two previous smaller studies with Rindopepimut in GB conducted at M.D. Anderson and Duke University, which showed 24.6 and 24.4 month median OS, respectively, nearly doubling the life expectancy.
The data were described in an oral presentation at the 16th Annual Meeting of The Society for Neuro-Oncology (SNO) in Orange County, CA by the lead investigator on the study, Dr. Rose Lai M.D., Assistant Professor of Neurology in the Division of Neuro-Oncology, Department of Neurology, Columbia University Medical Center, and lead investigator on the ACT III study.
She said
“These data continue to suggest that Rindopepimut is extending survival well beyond what we have seen historically in this EGFRvIII patient population.”
Thomas Davis, M.D., Chief Medical Officer of Celldex Therapeutics confirmed
“The consistency of data from three separate studies, including a large multicenter trial, is very encouraging and clearly supports our plan to advance clinical development of Rindopepimut with ACT IV, a pivotal, randomized, blinded international Phase 3 study.”
The high level of immunity seen in vaccinated patients is again associated with loss of EGFRvIII at recurrence. Rindopepimut was generally well-tolerated with treatment duration up to more than 7 years; toxicities consisted chiefly of injection site reactions, while fatigue, rash, nausea and pruritus also occurred in >10% of patients. Activity and safety data are very consistent with previous smaller studies of Rindopepimut in GB conducted at M.D. Anderson and Duke University (ACTIVATE and ACT II).
Celldex Therapeutics is the first antibody-based combination immunotherapy company. Celldex has a pipeline of drug candidates in development for the treatment of cancer and other difficult-to-treat diseases based on its antibody focused Precision Targeted Immunotherapy (PTI) Platform.
Written by Rupert Shepherd