Iclusig, a drug manufactured by Ariad Pharmaceuticals to treat resistant chronic myeloid leukemia, gained FDA approval last December—almost three months ahead of the anticipated timeline.  Iclusig gained orphan product designation as it is intended to treat a rare disease or condition. The special FDA program provides for an expedited approval for drugs which may provide safe and effective therapy for patients with diseases which have no satisfactory alternative therapy. Iclusig works by blocking specific proteins which appear to encourage the growth of cancerous cells and is generally used when other similar tyrosine kinase inhibitors have failed to work or the cells have become resistant.

Sales of Iclusig, a drug used primarily in the treatment of chronic myeloid leukemia, were recently suspended in a joint decision between the FDA and Ariad Pharmaceuticals, the manufacturer of Iclusig. Iclusig gained FDA approval less than a year ago, in December, 2012. At the time the drug was approved—under an accelerated process –clinical trials had demonstrated a higher-than-normal risk of cardiovascular events among those taking Iclusig. This risk required Ariad to include a boxed warning alerting patients and physicians to the risks of blood clots and liver toxicity in patients taking Iclusig.

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. 

A recent suspension of sales of the drug Iclusig, used in the treatment of chronic myeloid leukemia and Philadelphia chromosome positive acute lymphoblastic leukemia, may have a ripple effect in the future. A paper slated to be published in the New England Journal of Medicine on November 7^th regarding the Phase II Iclusig Pace trial reportedly now requires modification in order to add toxicity and adverse event data following the FDA’s investigation. Even worse, those patients currently enrolled in an Iclusig clinical trial, or those taking the medication outside the trial may be faced with an agonizing decision: continue the drug which could potentially make the difference between a fatal disease and a chronic, but treatable disease, or stop taking the drug due to the high risk of negative health effects.