Ariad (ARIA) Shares Nosedive 75 Percent as FDA Partially Halts Leukemia Drug Trials

Shares of Ariad Pharmaceuticals, Inc. (ARIA) are getting hammered in early Wednesday trading after discussions with the Food and Drug Administration have resulted in a hold on trial enrollment for its kinase inhibiting leukemia drug Iclusig (ponatinib) because of safety concerns.

Iclusig was approved last December as a treatment for resistant or intolerant chronic myeloid leukemia and Philadelphia-chromosome positive acute lymphoblastic leukemia. The drug received accelerated approval for the indications based on phase 2 clinical data on only five years of clinical studies.

Follow up after 24 months of Iclusig therapy showed blood clots – called “serious arterial thrombosis” – occurred in 11.8 percent of patients. That’s up from the 8 percent of patients at 11-month follow-up evaluations. The increase in clots has spurred the FDA to allow current patients to continue with trials of Iclusig, but no new patients can be enrolled at this time until changes in dosing levels and modifications are enacted. Upon agreements with the FDA on these items, it is expected that enrollments will resume.

Researchers also observed that 6.2 percent of treated patients had cardiovascular events, 4.0 percent had cerebrovascular events and 3.6 percent had peripheral vascular events.  It was also noted that some patients had more than one type of event.

Reductions in dosing for current patients will be lowered from 45 mg daily to 30 mg daily unless a patient has achieved a major molecular response or reaches one in the future, in which case dosing will be dropped to daily level of 15 mg. Data from clinical trials has shown efficacy even after dose reduction.  Future consideration for enrollment will exclude patients who have experienced prior arterial thrombosis that has resulted in a heart attack or a stroke.

The FDA will be issuing a safety warning on Iclusig and Ariad will be changing its warnings on the box.

Ariad is currently running eight trials to evaluate Iclusig for a variety of tumors, including chronic myeloid leukemia, lung cancer, gastrointestinal stromal tumors, thyroid cancer, and Acute myeloid leukemia. The much-watched EPIC trial is comparing Iclusig to Novartis’ (NVS) Gleevec in chronic myeloid leukemia patients, which many analysts consider key to Iclusig reaching a greater patient population as an alternative for those who have grown resistant to current drugs.

Ariad entered Wednesday with a market capitalization over $3 billion, but the news has stripped the majority of the company’s value as toxicity concerns have investors questioning future sales. Shares closed on Tuesday at $17.14 and plunged as low as $4.00 (-76.7%) in today’s trading, before bouncing back up near $5.00 each to pare losses to around 70 percent as the lunch hour approaches.