Abatacept Gets Board's Recommendation

A Food and Drug Administration advisory committee recommended the approval of a new drug to treat rheumatoid arthritis. The recommendation for the drug, Abatacept, was officially given on Tuesday. The decision was made based on the results of past studies on abatacept's efficacy and potential risk factors.

Abatacept is a drug administered intravenously and serves primarily as a suppressor of certain areas of the immune system. Specifically, abatacept (its intended trade name being Orencia) modulates activity in immune systems by interfering with the activation of T-cell, a type of lymphocyte that play a large role in immune responses. The manufacturer, Bristol-Myers Squibb, pitches it as an alternative for patients who do not respond to existing treatments.

During the hearing, the FDA's Arthritis Advisory Committee voted 7-0 that the benefits of the drug outweigh the possible risks. In the end, the agency isn't required to follow the recommendations of its advisory committees, but generally does as such. The board reached its conclusion after examining the results of several clinical conducted on abatacept. According to one such study, 64% of a 424-patient sample size achieved significant primary physical function improvement compared to 39% of a sample size consisting of placebo patients after one year of treatment. The improvement was measured according to the Health Assessment Questionnaire.

Another study, one conducted with rats, found that the drug significantly inhibited the onset and progression of disease in a rat collagen-induced arthritis model. Paw swelling, collagen-specific antibodies and bone destruction were all inhibited by the treatment.

As with other drugs that affect the body's immune system, concerns were raised about abatacept. Concerns included increased risk for infections or cancer. Some studies of the drug showed a higher rate of occurrence of certain infections compared with a group taking a placebo. In the ASSURE (Abatacept Study of Safety in Use with other RA therapies) trial, the six patients who received both abatacept and a biologic RA therapy suffered from severe infections compared with one subject receiving placebo and a biologic. Of note, a biologic is a substance that is synthesized from living organisms or their products and used as a diagnostic agent. The board was concerned with the potential for increased risk of malignancy, i.e. the formation of malignant tumor. As the FDA has noted, immunosuppressant drugs are known to be associated with increased risk of malignancy.

Article References
FDA Panel Wants Arthritis Drug Approved, site accessed on 09/13/05

Bristol Abatacept Infection, Malignancy Risk To Be Considered By Advisory Committee, site accessed on 09/13/05