FDA approves Provenge prostate cancer vaccine

By Candy Lashkari

Cancer may now be fought with a vaccine. The FDA has finally approved an immune boosting vaccine which is said to extend survival of patients at an advanced stage of prostate cancer by four months. This is twice as long as what could be expected with regular chemotherapy. There is also an increase of three years survival after detection in initial stage by 38% thanks to the vaccine.

Immunologist Edgar G Engleman of the Stanford University School of Medicine first discovered the way to harness the body’s immune cells to fight against prostate cancer about two decades ago. In Engleman’s experiment he would expose the immune system to proteins made by the cancer cells to prime the body to fight the cancer more aggressively.

This was done by collecting specialized immune cells called dendritic cells from the patient’s blood and mixing them with proteins collected from the surface of prostate tumor cells. This cocktail mixture was then injected back in to the patient in three doses at regular two week intervals.

“A lot of people have been working in labs, biotechs and pharma companies looking for a proof of principle that immunotherapy works against cancer. This is the proof of principle” said Dr. David I. Quinn, medical director of the USC Norris Cancer Hospital.

The new vaccine has been called Provenge and is developed by the biotechnology company Dendreon. The biotechnology company’s share prices went up by more than 30% after the health officials at the FDA confirmed that the Provenge vaccine was approved.

The sales from the vaccine are expected to top $1 billion a year as per analysts. Jonathan Aschoff an analysts with Brean Murray Carret and Co has forecast annual sales figures of $1.45 billion in the year 2013 based on a higher than expected price. He expects the sales to top $2 billion.

"Provenge provides a new treatment option for men with advanced prostate cancer, who currently have limited effective therapies available," said Karen Midthun, acting head of the Food and Drug Administration's biologics center, in a statement released.

Before the release of the vaccine Provenge the only options were surgery, radiation, hormones and one chemotherapy drug called Taxotere. These would extend the life of advanced patients of prostate cancer by merely two months. However the study involving 512 patients with prostate cancer who used Provenge had far more encouraging results.

The overall survival rate increased by 4 months in advanced patients who were given the vaccine and median survival rates were boosted from 21.7 months to 25.8 months. Immune therapy is catching on with other companies like GlaxoSmithKline studying a lung cancer vaccine and Bristol-Myers Squibb is testing a melanoma vaccine.