The U.S. Food & Drug Administration (FDA) announced today that it had received more reports about the occurrence of a rare blood cancer – Hepatosplenic T-Cell Lymphoma (HSTCL) – in people treated with TNF blockers, a class of drugs that includes Remicade (infliximab), Enbrel (etancercept), Humira (adalimumab), Cimzia (certolizumab pegol) and Simponi (golimumab), as well as azathioprine and/or mercaptopurin.
HSTCL is a rare, aggressive cancer that is usually fatal. In a Drug Safety Communication issued today, the FDA said the majority of HSTCL cases reported were in patients being treated for Crohnâ€™s disease or ulcerative colitis, but also included a patient being treated for psoriasis and two patients being treated for rheumatoid arthritis.
As December 31, 2010, more than 40 HSTCL cases have been identified in the Adverse Event Reporting System (AERS) database, the medical literature, and the HSTCL Cancer Survivors’ Network in association. These included 20 associated with Remicade, one with Enbrel, two with Humira, five with Remicade / Humira, 12 with azathioprine, and three with mercaptopurine. The FDA noted that in the 20 HTCL cases associated with Remicade, 18 of the patients also were known to be using concomitant mercaptopurine or azathioprine. Of the five cases identified with Remicade / Humira use, 4 patients were known to be using concomitant mercaptopurine or azathioprine.
In its Drug Safety Communication, the FDA said the product labels for Remicade and Humira have been updated to include warnings about HSTCL. The product labels for azathioprine and mercaptopurine would also be updated to include HSTCL warnings. The FDA said the risks and benefits of using TNF blockers, azathioprine, and/or mercaptopurine should be carefully weighed when prescribing these drugs to children and young adults, especially for the treatment of Crohnâ€™s disease and ulcerative colitis.
The FDA previously communicated about the increased risk of lymphomas and other cancers associated with the use of TNF blockers in children and adolescents in June 2008. It did so again in August 2009 when new warnings were added to the TNF blocker labels.
Crohn’s disease and ulcerative colitis cause inflammation of the digestive system that may cause pain in the abdomen, cramps, and diarrhea. Bleeding from the rectum, weight loss, joint pain, skin problems and fever also may occur. Children with the disease may have growth problems, develop intestinal blockage, and experience malnutrition.
Remicade, Enbrel, Humira, Cimzia and Simponi suppress the immune system by blocking the activity of TNF, a substance in the body that can cause inflammation and lead to immune-system diseases, such as Crohnâ€™s disease, ulcerative colitis, rheumatoid arthritis, ankylosing spondylitis, psoriatic arthritis and plaque psoriasis.
Azathioprine and mercaptopurin also suppress the immune system. They are commonly used as part of a combination regimen or used alone to treat Crohnâ€™s disease and ulcerative colitis, although they are not approved for those uses, according to the FDA.