Findings from the first group of six patients in the study, being conducted at the UCSF Brain Tumor Research Center, showed that vitespen (trademarked as Oncophage), a vaccine made from the patient's own tumor, was associated with tumor-specific immune response in patients with recurrent, high-grade glioma.
Glioma is a type of primary tumor that arises from the glial cells, the connective tissue cells that surround and support nerve cells. The most common site of involvement of a glioma is the brain. Malignant glioma is currently a fatal disease.
The trial results are being presented at the Immunotherapy Task Force Meeting, sponsored by the Society of Neuro-Oncology and the Joint Section of Tumors, during the Society's 11th annual scientific meeting in Orlando, Fla., on November 16, 2006.
"This is the first documentation of a glioma-specific immune response after vaccination with vitespen," said Andrew T. Parsa, MD, PhD, assistant professor in the UCSF Department of Neurological Surgery and principal investigator of the trial.
"Based on preliminary observation of patients in the first cohort, the tumor-specific immune response evoked by vitespen vaccination may be associated with clinical benefit in these patients with recurrent glioma, including improved progression-free survival and overall survival compared with historical controls. Further studies are certainly warranted to definitively determine the benefit of vitespen in this patient population," he said.
Derived from each individual's tumor, vitespen contains the "fingerprint" of the patient's particular cancer and is designed to reprogram the body's immune system to target only cancer cells bearing this fingerprint. The vaccine is intended to leave healthy tissue unaffected and limit the debilitating side effects typically associated with traditional cancer treatments such as chemotherapy and radiation therapy. Vitespen has been granted fast track and orphan drug designations from the Food and Drug Administration in both metastatic melanoma (skin cancer) and renal cell carcinoma (kidney cancer).
The UCSF clinical trial is a phase1/2 study designed to establish the feasibility, safety and preliminary efficacy of vaccination in patients with recurrent, high-grade glioma. The trial involves two groups of six patients, both of which receive a minimum of four injections: the first group receives biweekly vaccinations and the second receives weekly vaccinations. Patients are monitored for immune response before, during and after treatment.
In the first group, study results showed tumor-specific immune response was detected after vaccination in all six patients. Researchers observed that patients whose disease was stable after surgical resection and before vaccination were more likely to respond clinically. Of the first six patients treated, five have exceeded the historical median benchmark of 6.5 months survival from time of recurrence. All six have exceeded the overall survival historical benchmark of 14.6 months from time of diagnosis.
The UCSF investigators will continue to follow patients for progression-free survival and overall survival. According to investigators, no adverse events or toxicity identified were considered attributable to the vaccine. Based on these preliminary findings, a larger phase 2 study is planned for 2007.
Rosalind Hekkala, a 66-year-old woman from Reno, Nev., who was enrolled in the first study group, was originally diagnosed with a brain tumor in July 2005. She had surgery to remove it, but the tumor returned in November. Her daughter learned of the trial at UCSF and Hekkala enrolled. In January 2006 she had another surger y, and this time, the removed tissue was sent to Antigenics, the Massachusetts biotech company that produces the vaccine from the patient's tumor tissue. Because of the size of the tumor, Hekkala will receive injections every other week until mid-February. So far, results are promising with no sign of tumor regrowth, according to the Parsa.
"Every day I feel better," Hekkala said on a recent visit to UCSF to receive her injection. "I set small goals for myself and I keep meeting them. I am very hopeful that this vaccine is the answer."