FDA Releases 1st Therapeutic Cancer Vaccine

The field of cancer immunotherapy received an important boost last week with the FDA’s approval of the first therapeutic cancer vaccine, sipuleucel-T (Provenge). The vaccine was approved for some men with metastatic prostate cancer based on the results of a phase III randomized trial. However, because of the way in which the vaccine is produced, its availability will be very limited for at least the next 12 months.
Approval of the vaccine by the FDA is important on several levels, said Dr. Philip Kantoff, director of the Lank Center for Genitourinary Oncology at the Dana-Farber Cancer Institute and the IMPACT trial’s principal investigator. “This represents the first proof of principle that immunotherapy works and can work in cancer in general,” he said. “I’m hopeful that investigators will look at this as an opportunity to build upon these findings and improve upon them with other treatment strategies.”
From a clinical perspective, Dr. Kantoff continued, many men with advanced prostate cancer whose tumors are no longer responding to hormonal therapy—often called hormone-resistant or castration-resistant cancer—now have a new, relatively nontoxic treatment option. The only other approved treatment for such patients is the chemotherapy drug docetaxel (Taxotere), which, on average, improves overall survival by 2.4 months. The vaccine offers “meaningful benefits for patients,” Dr. Kantoff said. “It’s not a cure for cancer, of course, but it does provide a significant clinical benefit.”
A Different Paradigm
The FDA’s decision marks the end of a somewhat tumultuous 15-year journey for sipuleucel-T and the company that developed it, Seattle-based Dendreon.
The available data on immunotherapy, he said, “suggest that it establishes a new balance” in patients. With the vaccine’s assistance, “the immune system restricts the growth of the tumor. Some tumor cells might be dying, but generally the tumor has to fight harder to grow, and the immune system is more able to fight back to keep it in check,” he explained.
Early Challenges
Initially, the vaccine’s manufacturing requirements will limit its impact on patients, Dendreon officials acknowledged. Currently, the company has only one licensed manufacturing facility in New Jersey, which is operating at 25 percent capacity. Two other manufacturing facilities, one in Georgia and the other in California, are expected to be completed and receive approval from the FDA to manufacture the vaccine by mid-2011, meaning that for the next 12 months “the demand will exceed the supply,” said Dendreon CEO Dr. Mitch Gold during a telephone briefing.
For the next year, the treatment will be available to approximately 2,000 patients at 50 oncology and urology clinics that were approved sites for the sipuleucel-T clinical trials, company officials explained. The three-course treatment will cost $93,000, which the company expects will be covered by private insurers and Medicare.
“Having something approved allows us to start those trials,” Dr. Drake stressed. “It allows us to use vaccines in combination with other therapies. Because we know from animal models that immunotherapy can be at least additive and sometimes synergistic with other therapies, this [approval] gives us legs to go earlier and with combinations.”