Mylotarg withdrawn: it causes death and doesn't work

Should the FDA have approved Mylotarg?

Pfizer has announced a voluntary withdrawal of Mylotarg, a drug that has been used to treat patients with acute myeloid leukemia (AML) for the last ten years, after studies revealed that Mylotarg does not actually work and in fact can be fatal for those taking it.

The news has raised questions about the safety and effectiveness of the FDA's accelerated approval program under which Mylotarg was given the green light in the first place.

Mylotarg was approved in May 2000, to treat patients over the age of 60 with recurrent AML who weren't considered eligible for other forms of chemotherapy, according to a Pfizer press release.

The FDA's accelerated approval process allows drugs to be approved based on preliminary data and the pharmaceutical company behind the drug is then required to conduct further trials in order to establish whether the drug does in fact do the very thing it is marketed for.  

The FDA explained the process when announcing the withdrawal of Mylotarg: "This program allows the agency to approve a drug to treat serious diseases with an unmet medical need based on a surrogate endpoint – a laboratory measurement or a physical sign used as a substitute for a clinically meaningful endpoint that directly measures how a patient feels, functions, or survives."

Clinical trials of Mylotarg

According to Bloomberg: "Wyeth, which sold Mylotarg before being purchased by Pfizer in October, didn’t start mandated follow-up research until 2004 and didn't provide results until this year."

Many in the industry are now wondering why in fact it took so long for these trials to begin and for the results to be made public.

During the trials, Mylotarg was revealed to be ineffective and was "linked to deaths from liver and lung complications" reported Bloomberg.

Robert Kane, acting deputy director for safety in the FDA's Division of Hematology Products, told Bloomberg that "accelerated approval still has a place in the approval process but it's also more important that we learn over the years that the whole development plan be set up well in advance."

"The trials should be planned and if possible under way when the sponsor submits the application" Mr. Kane continued.

Mace Rothenberg, Pfizer's head of oncology development, said that the pharmaceutical company is "disappointed that the study did not confirm the clinical benefit of Mylotarg".

What does this mean for the FDA?

Mylotarg is the first drug that was approved in the FDA's accelerated approval program to be taken off the market and, since the decision, Pfizer stocks have been falling.

However, according to Ira Loss, an analyst at Washington Analysis who has followed the FDA for more than three decades, the problem really lies with the FDA and said "That makes it a big deal" but that "I don't think it’s a big deal for Pfizer."

Perhaps it is now time for the FDA to really review the accelerated approval program and evaluate whether the agency should be continuing with this process.

If ineffective, fatal drugs can be on the market for a decade, something clearly needs to be altered.

The true problem, as Jonathan Rabinovitz from the Stanford School of Medicine pointed out: "The FDA can speed up the steps to get [drugs] onto the market, but can it speed up the steps to pull them off?"

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