The Food & Drug Administration has released a “Question and Answer” document to supplement the public health alert it released last month regarding TNF blockers, such as Humira, Enbrel, and Remicade, and cancer in children and teens.

In children, TNF blockers are used to treat rheumatoid arthritis, inflammatory bowel disorder and Crohn’s disease. They are also approved to treat a variety of chronic, inflammatory and autoimmune system diseases including juvenile idiopathic arthritis, rheumatoid arthritis, psoriatic arthritis, plaque psoriasis and ankylosing spondylitis. TNF blockers work by neutralizing a protein that, when overproduced, causes inflammation and damage to bones, cartilage and other tissue.

The FDA had been studying the link between the pediatric uses of TNF blockers and cancer since 2008. In early August, the FDA had said that there were 11 deaths among the 48 cases of cancer in children treated with the drugs.   The causes of death included hepatosplenic T-cell lymphoma (9 cases) and T-cell lymphoma (1 case). In the remaining case, the patient died from sepsis after achieving remission of the lymphoma. The agency said it had mandated that the Black Box  Warnings on these drugs – known as TNF blockers -   highlight their possible  association with lymphoma and other cancers in children and teens.

According to the  “Question and Answer” document released yesterday,  the following types of pediatric malignancies were reported in children treated with TNF blockers between 2001 and 2008:

Hepatosplenic T-cell lymphoma, 10 cases
Non-Hodgkin’s lymphoma, 7 cases
Hodgkin’s lymphoma, 6 cases
Leukemia, 6 cases
Malignant Melanoma, 3 cases
Thyroid cancer, 3 cases
Basal cell carcinoma, 1 case
Lymphoma and AML, 1 case
Leiomyosarcoma, 1 case
Nephroblastoma, 1 case
Renal cell carcinoma, 1 case
Metastatic hepatocellular cancer, 1 case
Malignant mastocytosis, 1 case
Neuroblastoma, 1 case
Colorectal cancer, 1 case
Yolk sac tumor, 1 case
Myelodysplasia, 1 case
Bladder cancer, 1 case

These 48 cases of pediatric cancers included both U.S. (32) and non-U.S. (16) cases.   According to the document, 31 cases of malignancy were reported in children taking Remicade, including 10 cases of hepatosplenic T-cell lymphoma in patients with inflammatory bowel disorder; 15 cases of malignancy in children receiving Enbrel were reported; and  two cases of malignancy in children receiving Humira were reported.  The FDA also said that the 48 cases of pediatric cancers did not confirm a dose association with malignancy.