LEXINGTON, Mass., Aug. 8, 2012 (GLOBE NEWSWIRE) -- Agenus Inc. (Nasdaq:AGEN), a biotechnology company working to develop novel immunology-based treatments for cancers and infectious diseases, today announced the publication of key clinical data from a Phase 1 trial of a Prophage Series vaccine (HSPPC-96; vitespen) to treat patients with recurrent glioblastoma multiforme (GBM). The data from the Phase 1 trial were published online by Clinical Cancer Research in an article titled, "Individual patient-specific immunity against high-grade glioma after vaccination with autologous tumor derived peptides bound to the 96 KD chaperone protein," by Andrew T. Parsa, MD, Ph.D., Professor in the Department of Neurological Surgery at the University of California, San Francisco (UCSF), and principal investigator for the trial. This data will appear in the printed version this fall. "Our data show that a tumor specific immune response to peptides bound to gp96 can be generated with autologous HSPPC-96 derived from GBM patients undergoing surgical resection," said Dr. Parsa. "In addition, our observations provide evidence for a general mechanism to elicit individual patient-specific immune responses that appear to correlate with clinical outcome. The results affirm the safety and biological activity of an autologous HSPPC-96 approach for recurrent glioma patients." A total of 12 patients with a mean age of 52 years were treated in the Phase 1 trial receiving HSPPC-96 as a single-agent therapy. Testing of peripheral blood leukocytes (PBLs) before and after vaccination revealed a significant peripheral immune response specific for the peptides bound to HSP-96, in 11 of the 12 patients treated. Brain biopsies of immune responders after vaccination revealed focal CD4, CD8 and CD56 IFN-gamma positive cell infiltrates, consistent with tumor site-specific immune responses. Immune responders had a median survival of 47 weeks after surgery and vaccination, compared to 16 weeks for the single non-responder. There were no serious adverse events associated with vaccine administration.