Celldex Therapeutics announced mature overall survival (OS) data from ACT III, a Phase 2 study of rindopepimut (CDX-110) in patients with newly diagnosed EGFRvIII-positive glioblastoma. ACT III was a multicenter, single arm trial that enrolled 65 patients with newly-diagnosed and optimally resected EGFRvIII-expressing glioblastoma. About 3 months post-diagnosis and following treatment with standard chemoradiation, patients started vaccination with rindopepimut in combination with standard of care temozolomide therapy.

The data showed a final median OS of 24.6 months from diagnosis, which is significantly better than 15.2 months for a historical cohort of patients selected to match ACT III eligibility criteria. The results for the predefined primary endpoint (66% Progression Free Rate or “PFR” at approximately 8.5 months post-diagnosis) show a statistically significant improvement (P=0.0168, 95% CI) over a predetermined estimate of 53%, which was a high estimate derived from published results for standard chemoradiation with temozolomide (45%) and a cohort of patients with tumors expressing the EGFRvIII oncogene selected to match major ACT III eligibility criteria (29%).

Rindopepimut is an investigational immunotherapeutic vaccine that 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.

For more information call (781) 433-0771 or visit www.celldextherapeutics.com.