Delay in Approval of Cancer Drug Sparks Heated Debate

FDA's decision not to approve the experimental prostate cancer therapy Provenge has produced an "unusually bitter debate," the Washington Post reports (Stein, Washington Post, 7/6).

FDA in May withheld approval of Seattle-based Dendreon's Provenge and instead issued an "approvable" letter, a move that could delay approval of the drug for at least two years.

Provenge is a so-called cancer vaccine, part of an experimental class of treatments designed to use the body's white blood cells to attack tumors.

An FDA advisory panel in March recommended that the agency approve Provenge, voting 17-0 that the drug was "reasonably safe" and 13-4 in support of its efficacy. However, neither of the two late-stage studies that Dendreon submitted to FDA reached their stated endpoints. The studies' results failed to show that Provenge slowed tumor growth, which was Dendreon's original intention.

An unplanned analysis performed on a 127-patient study that failed to meet its primary goal suggested that patients taking the drug lived 4.5 months longer than those who were not on the drug.

FDA in its letter asked for additional clinical data to support Dendreon's claim that the drug is effective. FDA also is seeking additional information on the drug's chemistry, manufacturing and controls section of the approval application (California Healthline, 6/5).

After FDA decided against approval, patients and advocacy groups "mounted an orchestrated lobbying effort" to reverse the decision, the Post reports. Provenge advocates started a letter-writing campaign, created Web sites, led a Capitol Hill rally and demanded a meeting with FDA Commissioner Andrew von Eschenbach, which they received.

In addition, they "began lobbying to amend FDA legislation moving through Congress to allow easier access to experimental treatments," the Post reports.

Two members of the Provenge FDA advisory panel who specifically questioned the drug's effectiveness -- Howard Scher of Memorial Sloan-Kettering Cancer Center and Maha Hussain of the University of Michigan -- "fear[ed] for their safety" at a recent meeting of the American Society of Clinical Oncology after Provenge advocates indicated they would show up to protest the FDA decision, the Post reports.

Hussain said, "We have been harassed and trashed for giving our opinion in an area of our expertise. It's been a nightmare, to say the least."

According to the Post, the debate over Provenge "illustrates the highly charged atmosphere that often surrounds new treatments as the desperation of deathly ill patients increasingly converges with the high-stakes intensity of biotech investing in the anything-goes forum of the Internet."

Marie Hojnacki, who studies patient advocacy groups at Penn State University, said, "Something has changed. It's become an increasingly competitive atmosphere, and both patient advocacy groups and others, including pharmaceutical companies, are doing what they feel like they need to do, which means being very aggressive about getting what they want" (Stein, Washington Post, 7/6).