Antigenics Cancer Vaccine, In Small Study, Helps Brain Tumor Patients Live Longer

11/24/08Follow @xconomy

(Update: Antigenics stock surged 13 percent today after this news appeared.)

Antigenics is offering a glimmer of hope for patients with terminal brain tumors. The Lexington, MA-based biotech company said its experimental treatment, designed to stimulate the immune system to fight cancer, helped a small group of patients live about four months longer than their doctors expected.

The trial looked at 12 patients who took vitespen (Oncophage) in a study at the University of California San Francisco, Antigenics (NASDAQ: AGEN) said in a statement. It found that patients with relapsed glioma lived a median time of 10.5 months, meaning half lived longer, and half died sooner. There was no control group in the study to give researchers a definitive sense of how much better this treatment was than standard treatment, but patients with this prognosis historically have a life expectancy of 6.5 months after surgery to remove the malignancy, according to research presented at the Society for Neuro-Oncology meeting in Las Vegas.

Patients may be living longer because the Antigenics therapy appears to have done what it was supposed to do—ignite T cells and Natural Killer cells of the immune system to fight cancer cells like they would normally attack a virus. Researchers saw that kind of immune reaction to tumors in all 12 patients, and didn’t see any serious side effects attributed to the drug. Gliomas are the most common type of brain tumor, affecting an estimated 19,000 people each year in the U.S., according to the National Cancer Institute. The disease has taken on a higher profile this year than ever before, as Sen. Ted Kennedy and the golfer Seve Ballesteros were diagnosed with brain tumors.

“These are the most challenging patients to treat because their survival is typically three to six months,” Andrew Parsa, a neurosurgeon at UCSF and the study’s lead investigator, said in a statement. “These preliminary results suggest a possible impact on survival as well as a very favorable safety profile.”

The findings show a wide range of variability in how patients responded to the treatment. Four patients lived more than a year, and one lived for 2.5 years after getting the therapy, Antigenics said.

Antigenics has struggled to get traction with vitespen ever since March 2006, when the treatment failed to reach its main goal in a study of 604 patients with kidney cancer. On further analysis, however, the treatment did appear to extend lives for two-thirds of patients with low to moderate risk of recurrence. That was good enough for the company to win clearance to market the treatment in Russia earlier this year, and compelling enough to at least try to win approval in Europe. The company hasn’t tried to get approval from the FDA, because the agency usually considers such retrospective data-slicing to be a fishing expedition for something positive, and not statistically valid.

The Antigenics treatment is thought to be useful against multiple forms of cancer because it is designed to be personalized, made by slicing out a portion of a patient’s tumor. The tumor tissue is frozen and shipped to the Antigenics plant in Lexington, where it is chopped up, and key proteins filtered out. The treatment is shipped back to the doctor, then injected back into the patient to “teach” the immune system to spot the hallmarks of cancer cells and mount a defense against them. Patients usually get their personalized vaccine four to six weeks after tumors are removed, the company has said.

Antigenics has another trial enrolling 30 patients with relapsed gliomas, which began in October 2007. The results are expected next year. Between its treatment for kidney cancer and its latest brain cancer study, the company has to hope that it can eke out enough positive sentiment—and revenue—to keep operating so it can get a chance to look at those results. The company had an $11.1 million net loss in the third quarter, and $40.9 million in cash and investments left at the end of September. Its options to raise new capital are limited, with a stock price beaten down to 54 cents as of Friday’s close.

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