Pfizer and Celldex Therapeutics Present Update on CDX-110 (PF-04948568) Phase 2 Brain Cancer Studies at 45th Annual ASCO Meeting
ORLANDO, Fla. - (Business Wire) Pfizer (NYSE: PFE) and Celldex Therapeutics (NASDAQ: CLDX) today announced the presentation of updated data from two clinical trials of CDX-110 in newly-diagnosed glioblastoma multiforme (GBM) at the 45th Annual Meeting of the American Society of Clinical Oncology (ASCO). CDX-110, an investigational immunotherapeutic vaccine that targets the tumor-specific molecule, epidermal growth factor receptor variant III (EGFRvIII), was developed by Celldex Therapeutics and is now partnered with Pfizer.
“Data from the 40 evaluable patients in ACTIVATE and ACT II continue to suggest that vaccination with CDX-110 may be able to improve time to tumor recurrence and overall survival when used in patients with newly-diagnosed GBM. These data also continue to suggest that tolerability and side effects associated with CDX-110 are minimal. These results are very encouraging and we look forward to the results from the ongoing multi-center ACT III Phase 2 study,” said John H. Sampson, MD, PhD, Associate Deputy Director of The Preston Robert Tisch Brain Tumor Center at Duke University Medical Center.
ACTIVATE Results:
In this single arm Phase 2 study, 18 patients with newly diagnosed and optimally resected EGFRvIII-positive GBM received CDX-110 as a monotherapy following completion of chemoradiation with concurrent temozolomide. Median overall survival (OS) was 26 months and median time to progression (TTP) was 14.2 months. Additionally, three patients remain without relapse more than 4 years from surgery and continue to receive the vaccine within the clinical trial.
ACT II Results:
In this single arm Phase 2 study, 22 patients with newly diagnosed and optimally resected EGFRvIII-positive GBM received CDX-110 in combination with maintenance temozolomide after having completed chemoradiation with concurrent temozolomide. Median time to progression (TTP) is 15.2 months and three patients continue without relapse after more than two years. Results to date from this ongoing study estimate median overall survival to be 23.6 months (data are not yet final). In addition, and in line with preclinical data that suggested the combination with temozolomide could augment immune responses, patients show robust serological evidence of an immune response against EGFRvIII.
Efficacy data from both ACTIVATE and ACT II compare favorably to data for a historical control group of 17 patients, matched for EGFRvIII expression, extent of resection and performance status (Median TTP: 6.3 months; Median OS: 15.0 months). In both studies, CDX-110 was generally well tolerated with local injection site reactions being the most commonly reported toxicity.
Additional Results:
In addition, preliminary data from a pilot study in a small number of patients with newly diagnosed GBM will be presented. In this study, CDX-110 was given in combination with daclizumab, an antibody that blocks suppressive T cells, to determine whether this combination could further augment immune responses. This data will be presented in a poster session on Sunday, May 31 from 8:00am – 12:00pm EDT.
ACT III, a multicenter, single-arm Phase 2 clinical trial in GBM in which all patients will receive CDX-110 in combination with maintenance temozolomide, is ongoing. Total enrollment is expected to be approximately 60 patients. In addition, Pfizer and Celldex are working on the design of a randomized Phase 2 study in GBM to compare CDX-110 plus standard of care to standard of care alone.
About CDX-110 (PF-04948568)
CDX-110 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. It is reported to be present in 25-40 percent of GBM tumors. |
