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how well Dendreon will be able to seize this new opportunity. It doesn’t have enough manufacturing capacity to meet all the anticipated demand from prostate cancer patients on Day 1, and it has to strike a delicate balancing act on pricing the product so as to maximize profits without alienating doctors and patients. Since the product involves incubating patient’s own white blood cells with a complex engineered protein, the manufacturing and shipping logistics are more complicated than they would be for a usual pill in a bottle. Any slip-ups could lead to shortages of a potential life-saving product, which is the kind of the PR nightmare all biotech companies fear (see: Cambridge, MA-based Genzyme).
But today’s FDA approval is a vindication for a company that has persevered through some fascinating twists and turns over the years, which I summarized in an in-depth feature story for Xconomy in April 2009. The dream of getting an FDA-approved cancer immunotherapy has eluded dozens of biotechs over the past two decades, including notables like Cell Genesys, Antigenics, Genitope, and Favrille. In Seattle, Xcyte Therapies failed to get its immune-booster through the FDA, and now Oncothyreon’s partner, Merck KGaA has been tripped up by an unexpected side effect seen in a clinical trial.
Here’s some of the Dendreon history that can be useful for people trying to understand the context around why today’s news is a big deal.
Dendreon’s treatment doesn’t work like a traditional chemotherapy or even a targeted antibody drug that’s supposed to seek out cancer cells and spare healthy ones. Instead, the Dendreon treatment is designed to trigger the body’s natural immune defenses to recognize cancer cells as foreign invaders, like a virus, and kill them.
Here’s how this works: Dendreon’s approach requires blood to be drawn from a patient, and some white blood cells vital to the immune system, called dendritic cells, to be separated in a lab. The cells are shipped to the company’s factory in New Jersey, and incubated with a genetically engineered protein found on prostate cancer cells, called PAP. This process is supposed to “teach” the immune system to recognize cells with this marker as foreign and fight them, and is sort of like waving a red flag to get the attention of a bull. The newly revved-up white blood cells are shipped back in cold storage from the Dendreon factory to the clinic, and re-infused into the patient, giving them new ability to fight off the cancer. The patient gets three of these infusions at the clinic over a one-month period, and then he’s done.
Much of the theory and practice of boosting patient’s own blood cells was worked out at Dendreon in the 1990s, and the company thought it had seen enough promising anti-tumor activity to take Provenge into the third and final stage of clinical trials, back in 1999. The gold standard measurement of effectiveness then, and now, for all cancer drugs would be a clinical trial that randomly assigns people to either the experimental drug or a placebo. Researchers would then follow patients for years to see if those on the drug live longer, with acceptable side effects in the eyes of the FDA.
Dendreon, like many biotech companies, couldn’t afford to wait around … Next Page »
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