Provenge Becomes First Cancer Immunotherapy Approved

Can you hear that? It’s the sound of champagne corks popping across Seattle today. Dendreon has at long last won FDA approval for its prostate cancer vaccine Provenge. Though not exactly a surprise, the regulatory nod it is still big news for Dendreon, which has struggled for years to bring the immunotherapy to market. In the broader scientific terms, Provenge will be the first therapeutic vaccine approved for cancer. On a conference call this afternoon, Dendreon’s president and CEO Mitchell Gold called it “the dawn of an entirely new era of medicine,” one in which a patient’s own immune system can be wrangled to combat cancer. Provenge works by prompting a patient’s immune system to wage its own battle against the disease. A blood sample is taken from a patient in order to isolate dendritic cells, which deliver antigens to T-cells and B-cells, the lymphocytes that control the immune response. Those dendritic cells are then cultured with the general component, prostatic acid phosphatase, a recombinant protein found in 95% of prostate cancers. The dendritic cells, now loaded with the antigen, are then injected back into the patient to trigger a reaction from the immune system. Patients receive three doses of the vaccine over the course of a month. The vaccine has had its ups and downs. When we wrote a lengthy piece on cancer vaccines back in 2006, the field seemed on the cusp of a breakthrough with Provenge. Then, just a year later, FDA said it would need more data on the therapy. Patients were outraged, some claiming foul play by members of the panel. It wasn’t uncommon to see small groups handing out pamphlets or picketing at annual meetings of the American Society of Clincial Oncology. Dendreon preserved, running another trial and finally reaching the finish line. So now that the drug is finally available, down to the practicalities. First, how much will it cost? Speculation on this point had been rampant. Xconomy recently broke down different analyst estimates for price-per-patient, which ranged from $40,000 all the way up to $100,000. Today it became clear the biotech was aiming for the higher end of that range: Dendreon will charge $31,000 per infusion, and a full course of treatment typically calls for three infusions. Or, in the awkward—some might say grim--assessment by the company’s COO Hans Bishop, that’s $23,000 per month of life extension for these patients. Second, how many people will be able to get it? Dendreon said current capacity can accommodate 2,000 patients its first 12 months on the market. The biotech is launching the drug out of its N.J.-based facility, which it started building back in 2006 and is currently operating at 25% capacity, and is meanwhile finishing up construction and licensing of two more sites. Within a year, all three plants are expected to be up and running at full steam. Physicians are now being trained in the production process (the drug is, after all, based on one’s own cells), and Bishop says he expects the first patient to begin treatment within the week. Last, what other companies might be getting in on the Provenge boom? For right now, no one. Dendreon, which has yet to license the drug in Europe,  is “putting partnership discussions aside for now,” Bishop said. He noted that the European market is one-to-two times the size of the U.S. market, and the future opportunity there could be great. The idea of curing cancer by mustering the immune power within is an exciting one (not to mention one that has been around for awhile). Gold’s exuberance at this first approval is well taken, but it’s also important to recognize the current limitations of the approach. A lot of science has happened since Dendreon started developing Provenge, and with this first approval I’d be keeping an eye on other technologies that might prove more potent (including that going on within Dendreon's own labs).

Author: Lisa Jarvis

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