FDA: Pfizer will pull ineffective leukemia drug

Posted on Jun 24, 2010 in Health Optimization

AP Business Writer

updated 5:39 p.m. ET June 21, 2010

WASHINGTON – Federal health regulators said Monday that the drugmaker Pfizer has agreed to pull a leukemia drug off the market after a follow-up study showed it failed to slow the disease.

The Food and Drug Administration cleared the drug Mylotarg in 2000 under its accelerated approval program, which grants speedy access to drugs that show early promise. The drug was cleared for patients older than 60 with relapsed acute myeloid leukemia, a bone marrow cancer.

But the FDA said a follow-up study was halted last August after researchers reported more deaths among patients taking Mylotarg plus chemotherapy, compared with chemotherapy alone.

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The study was intended to show that adding Mylotarg to chemotherapy increased lifespan, which it failed to do.

Mylotarg carries a warning label about a sometimes fatal liver condition called veno-occlusive disease. The FDA said the rate of reports of the disease associated with the drug increased during its time on the market.

The drug will not be available to new patients, according to the FDA statement.

Pfizer said in a statement that patients currently taking the drug can continue taking it if their doctors approve. The drug will be officially withdrawn Oct. 15.

“We are disappointed that the study did not confirm the clinical benefit of Mylotarg,” said Dr. Mace Rothenberg, senior vice president for Pfizer’s cancer unit.

Dr. Mikkael Sekeres of the Cleveland Clinic said the drug caused disease remission in about 25 to 30 percent of his patients. However, he noted that the drug’s benefits came with increased toxicity, which can be fatal.

“What is concerning is that it took this long to come up with a confirmatory study for a drug that was approved,” based on preliminary data, said Sekeres, director of Cleveland Clinic’s leukemia program.

The confirmatory study was begun in 2004, four years after the drug was approved.

Last year the Government Accountability Office reported more than one-third of the studies FDA has required under its accelerated approval program are still pending. The GAO’s investigators said the FDA does not rigorously track whether companies are making progress on their required studies.

Pfizer, based in New York, acquired the drug with its 2009 buyout of competitor Wyeth.

Pfizer estimates less than 2,500 U.S. patients receive Mylotarg each year. Acute myeloid leukemia affects only about 13,000 patients in the U.S.

Pfizer shares fell 11 cents to $15.10 in trading Monday.

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