CAMBRIDGE, Mass (TheStreet) -- Blood clots and heart-related side effects have now forced Ariad Pharmaceuticals ((ARIA - Get Report)) to shut down a vital clinical trial involving its leukemia drug Iclusig, the company said Friday.
Ariad shares are down 33% to $3 in early Friday trading.
The so-called EPIC study was designed to compare Iclusig to Novartis' ((NVS - Get Report)) Gleevec in patients with newly diagnosed chronic myeloid leukemia (CML). Right now, Iclusig is used primarily in CML patients who no longer respond to first- and second-line therapies. If positive, the EPIC trial could have helped Ariad convince doctors to use Iclusig in earlier-stage CML patients, thereby greatly increasing sales.
Ariad's plan is now shot because of Iclusig's toxicity. The EPIC study is being discontinued because too many patients treated with the drug were reporting blood clots, the company said.
The decision to shutter the EPIC trial comes 10 days after Ariad stopped enrolling new patients into the study for the same heart-related safety concerns. The FDA has issued a warning to doctors about Iclusig's cardiac-related toxicity, although the drug has not been pulled from the market.
Ariad's stock price is down more than 80% since the company first admitted Iclusig's significant toxicity.
If Iclusig remains on the market, the drug will likely be used only in CML patients who have failed other treatments, or in a small subset of patients with a genetic mutation known as T35i.
-- Reported by Adam Feuerstein in Boston.