The FDA issued a safety communication over the leukemia chemotherapy drug ponatinib (Iclusig) after receiving reports of adverse cardiovascular events in patients taking the drug.

The FDA said it is investigating an increase in clinical trial and postmarket adverse event reports that showed patients treated with ponatinib experienced fatal heart attacks, worsening coronary artery disease, stroke, narrowing of large arteries of the brain, severe narrowing of blood vessels in the extremities, and the need for urgent surgical procedures to restore blood flow.

Ponatinib is a kinase inhibitor indicated for adults diagnosed with chronic phase, accelerated phase, or blast phase chronic myeloid leukemia or Philadelphia chromosome-positive acute lymphoblastic leukemia who no longer respond to previous treatment or who did not tolerate other treatment. The drug, which is manufactured by Cambridge, Mass.-based Ariad Pharmaceuticals, was approved in 2012 with a Boxed Warning and Warnings and Precautions sections detailing the risk of blood clots.

Recent clinical trial data showed that at least 20 percent of all participants treated with ponatinib developed blood clots or narrowing of blood vessels.

The FDA advised physicians to weigh the benefits and risks when prescribing ponatinib. The agency will provide information as it continues its investigation.