By Mary Welch

Dendreon Corp. received as part of its fifth round of financing a $10 million investment from Vulcan Ventures Inc. that will take the company's prostate cancer therapy into pivotal trials.

"Obviously we are very pleased but the round is still open and I am in discussions with other investors who are doing due diligence," said Martin Simonetti, chief financial officer for the privately held Seattle-based company. "We already have other investors, so we've raised more than $10 million. We certainly think that Vulcan's investment was a vote of confidence in our technology, our data and intellectual property position. They are very proactive in the biotechnology field and did a very thorough due diligence. They must have felt strongly about the data and the progress we are making as we go to Phase III trials."

Simonetti refused to say how much has been raised to date, what the intended financial target is or at what price the shares are being offered.

Besides Bellevue, Wash.-based Vulcan, other participants in this round so far include HealthCare Investment Corp., of Princeton, N.J.; New York Life Insurance Co., of New York; Sanderling Ventures Inc., of Menlo Park, Calif.; and Kummel Investments LLC, of Marietta, Ohio.

"I will say that after this round is finished, we will have a market cap of about $70 million," Simonetti said. "I will also say that Vulcan and HealthCare Investment are our two biggest investors and together they have about 50 percent of the company's equity."

When this financing round it finished, the company will have about 16 million shares outstanding.

The current financing round should allow Dendreon to complete Phase III trials of its dendritic cell therapy without needing to seek a partner, Simonetti said.

Founded in 1992, the company is focused on the development of cell-based therapies for the treatment of cancer and infectious disease. It has developed a platform for the isolation and activation of peripheral blood dendritic cells that allows the production of therapeutic agents.

Central to Dendreon's research approach is the use of dendritic cells, which are the only cells shown to initiate the production of "killer" T cells - a process essential for the elimination of tumors and virally infected cells, the company said.

In the prostate cancer study, the patient's dendritic cells are isolated from a unit of his blood. The dendritic cells are then activated using a proprietary prostate-specific antigen. These activated cells are returned to the patient to stimulate an immune response specifically against prostate cancer.

The company will start Phase III trials next month on APC8015, its antigen-loaded dendritic cell therapy, with 240 men with refractory prostate cancer. The trial will last 18 months, with any regulatory filing not occurring until 2002. The primary endpoint will be delay of disease progression. Patients will receive dendritic cells every two weeks for a total of three treatments. Patients who benefit from treatment may receive another boost six months after entering the study.

In Phase II trials, men who took APC8015 showed a median delay in disease progression of more than 300 days. In men who didn't take APC8015, the average disease progression time was 90 to 120 days. In addition, some patients experienced tumor regression or stabilization detected by changes in serum PSA level over time or by tumor shrinkage as measured by X-rays taken during treatment. Less than 10 percent of those receiving infusions had a mild fever or pain. No other side effects were noted.

The company is also planning to test APC8015 in patients with earlier-stage prostate cancer. In June, a new trial was started in men with hormone-sensitive prostate cancer.

The company expects to close this round of financing by year's end.