Years after accelerated approval debacle, FDA panel backs Pfizer's Mylotarg

An FDA panel voted on Tuesday that a new study supports the risk-benefit profile for Pfizer's Mylotarg.

Seven years after the FDA pushed Pfizer's Mylotarg off the market for flunking a confirmatory trial, it's in line for a return. An agency panel backed a new approval for the acute myeloid leukemia (AML) drug after Pfizer put up new data supporting its use.

By a 6-1 vote, an FDA advisory committee concluded on Tuesday that the data now show Mylotarg's benefits are worth its risks as part of a combo with chemo meds daunorubicin and cytarabine in adults with previously untreated de novo AML.

Back in 2010, Pfizer pulled the drug from the market at the FDA’s request after a postmarketing trial showed that it not only didn't help patients but may have even harmed them. Officials faced a host of questions at the time; for instance, why it took a decade for that follow-up data to arrive—Mylotarg was approved in 2000—and why the agency allowed Wyeth to wait four years to launch the postmarketing study. Pfizer acquired Wyeth in 2009.

Mylotarg was the first drug approved under the FDA's accelerated approval system to be withdrawn, the agency said at the time.

RELATED: Did the FDA drop the ball on Mylotarg?

All these years later, Pfizer returned to the agency with phase 3 data from a study in 280 adult patients aged 50 to 70, plus a meta-analysis from more than 3,000 patients in five phase 3 trials, according to a release from the drugmaker.

The FDA accepted Pfizer’s biologics license application in January. Pfizer has changed dosing since pulling the med from the market, a move one panel expert argued on Tuesday makes it more “tolerable.” In a briefing document, FDA reviewers said Mylotarg “demonstrated a treatment effect” on the study’s primary endpoint of event-free survival, but not on overall survival.

“FDA generally requires for approval that a new drug for first-line treatment of AML with curative intent demonstrates a survival benefit,” the reviewers wrote. Despite that analysis, multiple panelists said they backed the event-free survival endpoint.

The FDA doesn’t have to follow its expert committee’s recommendations, but it typically does. The agency’s decision date for the med is in September, according to Pfizer.

Mylotarg was originally approved as a single agent in first relapse patients aged 60 and older with CD33-positive AML.