Recently, Ariad Pharmaceuticals and the FDA have jointly decided to suspend sales of Iclusig, a drug used in the treatment of chronic myeloid leukemia and Philadelphia chromosome positive acute lymphoblastic leukemia. Iclusig gained FDA approval only last December under an accelerated process which required Ariad to conduct additional drug trials following approval. At the time of Iclusig’s approval, both Ariad and the FDA were well aware of the potential for blood clots and liver toxicity among those taking the drug. Because of those risks, the drug required a black box warning from the beginning. Unfortunately, it appears those risks are considerably higher than originally believed, and that as many as 20% of all patients taking Iclusig experienced dangerous blood clots. 24% of patients in one clinical trial suffered some sort of serious cardiovascular event while 48% in another trial suffered a heart attack, stroke or blood clot.

Iclusig is among only a handful of drugs used in the treatment of leukemia and is part of the class of Kinase inhibitors. Kinase inhibitors are also used to treat cancers such as melanoma, lung cancer, renal cancer and breast cancer and are used in certain instances to treat rheumatoid arthritis or prevent organ transplant rejection. Kinase inhibitors work by stopping the growth of cancer cells and preventing the spread of those cells. More specifically, Iclusig is a tyrosine-kinase inhibitor, meaning it disrupts enzymes within cancer cells. Iclusig is prescribed for those patients whose particular cancers are hard-to-treat or impervious to other forms of treatment including other tyrosine-kinase inhibitor drugs.