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.

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.