The cancer drug Mylotarg is being pulled from the U.S. market after the FDA determined that it was ineffective and endangered patients’ health.
Pfizer issued a Mylotarg recall from the market at the behest of the FDA following clinical trials where the drug performed poorly. Not only did the drug not appear to work, but the subjects taking Mylotarg had a higher death rate than those treated with traditional chemotherapy.
Mylotarg (gemtuzumab ozogamicin) was originally created by Wyeth, which was bought by Pfizer. The drug was approved in 2000 by FDA for the treatment of patients ages 60 and older with recurrent acute myeloid leukemia (AML). The drug was designed to treat patients who did not respond to chemotherapy well.
AML is a form of bone cancer that affects about 13,000 new patients each year in the U.S. Pfizer estimates that less than 2,500 patients a year were using Mylotarg.
According to the FDA, regulators knew that the side effects of Mylotarg included a link to veno-occlusive disease, a life-threatening liver condition, when it was first approved. However, a post approval clinical trial started in 2004 has revealed that the rate of patients who develop Mylotarg liver problems is higher than they initially believed.
The study included a total of 627 patients. Those given Mylotarg as part of their treatment suffered a 5.7% death rate, as opposed to a death rate of 1.4% among those just given traditional chemotherapy. In addition, the study’s results did not show any indication of a clinical benefit for those taking Mylotarg.
The drug was approved under an accelerated process for drugs that fill a serious medical need for which there is no other drug. The accelerated approval process requires that the drug company do follow-up clinical trials after approval. If the drug does not perform, or has serious health risks, the FDA can have the drug pulled from the market more quickly than it could a drug approved through normal means.
Under the terms of the Mylotarg recall, patients currently taking the drug and those patients who have had it prescribed may continue to take it, if they decide to do so after consultation with their physicians. However, Pfizer and FDA recommend that no new patients be prescribed the drug, and its new drug application will be officially withdrawn on October 15, 2010, according to a Pfizer press release (pdf). It is unclear how long the drug will be available for those currently taking it.
It is also unclear whether Pfizer will withdraw the drug from foreign markets as well. Pfizer’s press release only said that the company was in consultation with foreign health agencies over the issue.