To many people’s surprise on Friday the FDA approved Avastan in combination with the chemotherapy drug Paclitaxel for the treatment of breast cancer. Why was this a surprise?
The FDA’s advisory committee voted 5 to 4 against approving the drug. In the clinical trial Avastan did not demonstrate a statistically improved survival rate. However, it did show that the drug combination significantly slowed down the progression of the disease. (median survival for the Avasten group was 26.5 months vs 24.8 months for the control group just receiving Paclitaxel and disease progression was 11.3 months for the Avasten group vs 5.8 months for the control group).
So, what is he big deal? The FDA has stated in the past that it relies on survival advantage to approve a drug, not disease progression. In 2005 the FDA pulled from the market the drug Iressa which had been used to treat lung cancer. Iressa had not demonstrated an ability to extend survival time even though it did delay disease progression.
Then we come to the prostate cancer vaccine know as Provenge (see my many prior posts). Provenge demonstrated a statistically significant, 4.5 month survival advantage over placebo and the advisory committee reviewing Provenge overwhelmingly voted to approve the vaccine. Yet the politics at the FDA determined the vaccine was not ready to be approved. The FDA sent it back for additional data despite the fact that over 50,000 more men will die from prostate cancer without having the option to take advantage of the vaccine and its clearly demonstrated life extension ability.
What is more confusing is that Dr. Richard Pazdur, who oversees cancer drugs at the FDA, has stated that the agency favors over all survival as the standard for drug approval. He insisted that the decision about Avastin is not reflective of a change in FDA policies.
I don’t know why Genentech’s Avastin has rated such special handling. I am very pleased that the approval was given, as I do believe that we need drugs that will delay disease progression. I just don’t understand why we have to tolerate such inconsistent decision making from the FDA.
Joel T Nowak MA, MSW