Ariad crushed (again) after PhIII Iclusig trial is shuttered on blood clot fears

Faced with some serious safety issues, Ariad Pharmaceuticals ($ARIA) today said it will shut down its pivotal EPIC 3 clinical study of Iclusig (ponatinib), putting the company under a dark cloud.

A little more than a week ago, Ariad's stock tanked on the news that the FDA had put a partial hold on its clinical study of its drug for chronic myeloid leukemia after it became apparent that patients in the drug arm were experiencing an elevated rate of blood clots. Enrollment was stopped, dosing was cut and the company discussed a likely label change. The news wiped out the lion's share of the biotech's market cap.

Today, the news just got worse for investors, who watched Ariad's shares plunge yet again, dropping more than 30%. Over the past month the stock has dropped close to 80%, wiping billions of dollars out of its market cap.

Iclusig was given an accelerated approval for resistant or intolerant chronic myeloid leukemia and Philadelphia-chromosome positive acute lymphoblastic leukemia patients last December on Phase II data, which arrived just 5 years after clinical trials began for the drug. And the biotech had ambitiously pursued a slate of studies aimed at broadening its use among leukemia patients as it began marketing the drug at a cost of $115,000 a year.

The sudden end of the study and the likely damage to its commercial operations leaves Ariad in a perilous position. The company was heavily focused on rolling this treatment out in the U.S. and Europe while devoting a considerable amount of attention to R&D projects aimed at expanding its use. The question now is how the biotech will handle the investor backlash and questions from physicians and patients as CEO Harvey Berger--who had bullishly pushed ahead on his own with the drug--regroups and reorganizes. 

Analysts quickly began to question whether the drug can continue to be sold if it's too dangerous to use in a clinical study. The company says it is working with regulators on a label change.

"Our decision to stop the EPIC trial at this time is based on our current evaluation of the safety data in the trial since it was placed on partial clinical hold last week," stated Timothy Clackson, president of research and development and chief scientific officer at Ariad. "We believe that this is in the best interests of patient safety and the overall development of Iclusig."

Investigators tracked serious arterial thrombosis--blood clots--in 11.8% of Iclusig-treated patients after 24 months of therapy, up from the 8% rate seen after a year, prompting the company to lower the dose for currently enrolled patients from 45 mg to 30 mg daily. Investigators planned to exclude patients who had "experienced prior arterial thrombosis resulting in heart attack or stroke."

- here's the press release