By Mary Welch

Antigenics Inc. is taking its lead cancer product, Oncophage, into Phase III trials for the treatment of renal cell carcinoma.

"This is our first drug to enter Phase III trials, so we're very excited," said Gary Foster, the company's spokesman. "It is very significant for us."

The trial, which will start within a month, will take place at 80 centers worldwide and will include at least 500 patients. The trial should last about two years, with an expected new drug application filing in 2003. It will be the largest clinical trial of any patient-specific treatment tested to date, the company said.

The two-arm randomized study will compare surgical removal of the primary tumor followed by outpatient treatment with Oncophage to standard treatment, which is surgery. Study endpoints will include overall survival as well as progression-free survival.

In Phase II trials with patients with stage IV disease, 35 percent of the patients treated with Oncophage showed an improvement in the course of the disease. This includes responses seen in 10 percent of the patients, which is similar to what is observed with current treatments, plus stabilization of disease in 25 percent of the patients. Patients in the Phase II study had a life expectancy of several months to a year.

In addition to renal cell carcinoma, New York-based Antigenics has conducted clinical trials using Oncophage in other indications, including pancreatic, colorectal, gastric and kidney cancers, as well as melanoma and non-Hodgkin's lymphoma.

Oncophage is comprised of a specific class of proteins known as heat shock proteins. These proteins are manufactured from each patient's tumor tissue and contain a profile of signals, or the "antigenic fingerprint," of the patient's cancer. These signals have the capacity to activate the immune system to elicit an antitumor response.

Patient's tumors are shipped to Antigenics' facility in Woburn, Mass., where the individualized vaccines are manufactured in under 10 hours.

Oncophage is unpartnered and Antigenics intends to commercialize it in the U.S. and partner it elsewhere, Foster said.

Antigenic's stock (NASDAQ:AGEN) closed Wednesday at $16.75, up 62.5 cents.