After being on the market for 10 years and withdrawn for 7 years, Pfizer’s Mylotarg is set to make its return. The targeted acute myeloid leukemia drug on Friday won the FDA’s backing, again, marking the latest twist in its decades-long saga.
The drug has been approved to treat adult patients with newly diagnosed AML whose tumors express the CD33 antigen. Mylotarg can also treat patients 2 and older with relapsed/refractory CD33-positive AML, according to the FDA.
Originally approved under the FDA’s accelerated pathway in 2000, the Pfizer med, previously a Wyeth product, was removed from the market in 2010 after confirmatory trials raised concerns on safety and efficacy. Data showed it not only didn't help patients, it may have harmed them.
The agency faced a host of questions at the time about why it took a decade for that follow-up data to arrive 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 Mylotarg was the first drug approved under the FDA's accelerated approval system to be withdrawn, the agency has said.
Years after pulling the drug, the New York drugmaker refiled for approval in the U.S. back in January. This time around, it submitted new supporting data from a phase 3 study in 280 patients with AML aged 50 to 70, plus a meta-analysis from more than 3,000 patients in five phase 3 trials, according to an earlier release.
Addressing previous concerns, the new approval is for a lower recommended dose and a different dosing schedule, according to the U.S. drug regulator. An FDA committee voted 6 to 1 in favor of Mylotarg’s approval back in July.