Cases of a rare, aggressive, and usually fatal lymphoma continue to be reported in people being treated with tumor necrosis factor blockers, azathioprine, and/or mercaptopurine, the Food and Drug Administration announced in an April 14 statement.
The reports of the lymphoma, hepatosplenic T-cell lymphoma (HSTCL), have primarily involved adolescents and young adults being treated with these agents for Crohn’s disease or ulcerative colitis. One patient, however, was being treated for psoriasis, and two others for rheumatoid arthritis.
Most patients were on a combination of treatments that are known to suppress the immune system, but there have been cases in patients taking azathioprine or mercaptopurine alone, the statement 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 Crohn’s disease and ulcerative colitis," according to the FDA.
The statement recommends that health care professionals monitor patients on these treatments for malignancies and educate patients and their caregivers about the signs and symptoms of HSTCL, which can include splenomegaly, hepatomegaly, abdominal pain, persistent fever, night sweats, and weight loss.
The statement also notes that people with rheumatoid arthritis, Crohn’s, ankylosing spondylitis, psoriatic arthritis, and plaque psoriasis "may be more likely to develop lymphoma," compared with the general U.S. population, making it difficult to estimate the increased risk of malignancies associated with TNF blockers, azathioprine and/or mercaptopurine.
As of Dec. 31, 2010, the FDA’s Adverse Event Reporting System (AERS), the medical literature, and the Cancer Survivors Network had received the following unduplicated reports of HSTCL:
20 cases in patients taking infliximab (Remicade), including 18 patients also taking mercaptopurine or azathioprine.
• 1 case in a patient taking etanercept (Enbrel).
• 2 cases in patients taking adalimumab (Humira).
• 5 cases in patients taking a combination of infliximab and adalimumab (including 4 patients also taking mercaptopurine or azathioprine).
• 12 cases in patients taking azathioprine.
• 3 cases in patients taking mercaptopurine.
No cases have been reported in the TNF blockers certolizumab pegol (Cimzia) and golimumab (Simponi).
Reports of serious adverse events associated with these and other drugs should be reported online to the FDA’s MedWatch program or by phone to 800-332-1088.