Consistent data from three studies support plans for rindopepimut with ACT IV Phase 3 study

Celldex Therapeutics, Inc. (NASDAQ: CLDX) today announced the presentation of mature overall survival (OS) data for ACT III, a multi-center, single arm, Phase 2 clinical trial of rindopepimut (CDX-110) in patients with newly diagnosed EGFRvIII-positive glioblastoma (GB). 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 median OS data obtained from the 31 centers participating in the ACT III study are very consistent with two previous smaller studies with rindopepimut in GB (ACTIVATE and ACT II) conducted at M.D. Anderson and Duke University which showed 24.6 and 24.4 month median OS, respectively. These data were described in an oral presentation at the 16^th Annual Meeting of The Society for Neuro-Oncology (SNO) in Orange County, CA by the lead investigator on the study, Dr. Rose Lai.

“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”

Previously published retrospective analysis has documented that expression of the EGFRvIII oncogene correlates with poor long term survival. In ACT III, the two-year survival rate was 52% and compares very favorably with 6% for the matched EGFRvIII-positive historical cohort. The two-year survival data in ACT III is also consistent with the two prior studies, which each showed 50% survival at two years. In addition, data from ACTIVATE and ACT II have shown that approximately 20% of patients from each study continue treatment with durations of 6-8 years on study.

"These data continue to suggest that rindopepimut is extending survival well beyond what we have seen historically in this EGFRvIII patient population," said 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.

"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," said Thomas Davis, M.D., Chief Medical Officer of Celldex Therapeutics.