Pfizer Inc. has agreed to stop selling its leukemia drug Mylotarg because post-market research has shown it does not slow the disease it is supposed to treat.
The drug was first given the U.S. Food and Drug Administration's blessing in 2000 under the agency's accelerated approval program. It was to be used in people with acute myeloid leukemia (AML), a bone marrow cancer, who were over 60.
But the FDA said in a statement Monday that a follow-up study that began in 2004 showed no difference in survival time when gemtuzumab (Mylotarg) was paired with chemotherapy; more patients actually died on the combination treatment than on chemotherapy alone.
"Mylotarg was granted an accelerated approval to allow patient access to what was believed to be a promising new treatment for a devastating form of cancer," Dr. Richard Pazdur, director of the Office of Oncology Drug Products at the FDA's Center for Drug Evaluation and Research, said in a statement. "However, a confirmatory clinical trial and years of postmarketing experience with the product have not shown evidence of clinical benefit in patients with AML."
The FDA also said that Mylotarg was associated with a serious, and sometimes fatal, liver condition called veno-occlusive disease when it was first approved, and rates of this side effect have increased since 2000.
Mylotarg will not be available to new patients, but those who are currently getting the drug may complete their therapy following consultation with their health care professional, according to the FDA.