After years of speculation about the promise of cancer vaccines as a way to use the immune system against tumors, the United States will soon see its first cancer vaccine hit the market. Earlier today, the U.S. Food and Drug Administration announced that it was giving the green light to Provenge, a treatment for advanced prostate cancer that has spread to other parts of the body. The vaccine is designed to work by extracting a patient's own immune cells from blood and exposing them to a protein called prostatic acid phosphatase in the lab. When the cells are reinfused, they stimulate T cells to attack the patient's tumors.
Provenge, made by the biotech company Dendreon, is one of a wave of extraordinarily expensive new cancer therapies that, in clinical trials, extended survival only modestly. Patients who got it lived about 4 months longer, nearly 26 months total, than those who didn't—but that, say company executives, is still more than any other therapy has managed for this disease in a randomized trial. The vaccine is given in three infusions; each costs $31,000, for a total treatment tab of $93,000, the company said today.
A number of other cancer drugs, such as Avastin and Tarceva, cost tens of thousands of dollars a year and help patients live a few extra weeks or months. The modest benefit in part reflects the enormous challenge of treating metastatic disease, which is poorly understood and difficult to combat. New treatments are also more expensive to manufacture. Provenge executives say that they already took a big gamble, breaking ground on two manufacturing facilities even before the therapy was approved. In the first year of production, they still expect demand to exceed vaccine supply.