NEW YORK (AP) -- Ariad Pharmaceuticals is suspending sales of its leukemia drug Iclusig because of heightened concerns that patients could suffer from life-threatening blood clots. Shares of the drug developer slid in afternoon trading.
The Cambridge, Mass., company said Thursday that the Food and Drug Administration asked it to stop marketing the drug Wednesday afternoon. The FDA says 48 percent of patients treated with the drug in an early-stage trial and 24 percent who took the drug in a mid-stage trial have suffered serious side effects, including heart attacks and strokes, and some patients died as a result.
"At this time, FDA cannot identify a dose level or exposure duration that is safe," the agency said in a press release. The FDA some patients' serious side effects occurred as little as two weeks after patients started taking Iclusig.
Shares of Ariad Pharmaceuticals Inc. have lost three-quarters of their value, trading at their lowest level in three years, since concerns about an increased rate of side effects were disclosed earlier this month. The stock lost another $1.55, or 39 percent, to $2.41 Thursday.
Araid said it wants to resume selling the drug, and it's negotiating with the FDA about changes to prescribing information and new ways to manage risks. But Citi Investment Research analyst Jonathan Eckard said he thinks Iclusig will be off the market for several months, if not longer. He said Iclusig's market will be very limited if Ariad is able to resume sales.
The FDA said it can't say how many of the side effects are related to treatment with Iclusig because those trials did not compare the drug to an alternative treatment. But the rising rate of side effects and their pattern suggests that many of them are connected to Iclusig, the FDA said.
In December the FDA approved Iclusig as a treatment for two rare types of leukemia. It's a daily pill and Ariad's only approved product and brought in $13.9 million in sales in the second quarter.
On Oct. 9 the company disclosed a higher rate of side effects from Iclusig related to blood clots. Ariad said that after two years of research in a study, 11.8 percent of patients treated with the drug suffered a serious blood clot in an artery, worsening from the 8 percent rate after 11 months. The FDA halted enrollment of patients in new studies, and on Oct. 18 Ariad said it is ending a late-stage trial of the drug because of those side effects.
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