The Arthritis Foundation recently came out with its list of the top 10 arthritis events for the year 2007. This series will focus on those events.

#10: Evidence of benefit and safety of biologic therapy in children

Biologic agents have been widely prescribed for children to treat inflammatory forms of arthritis, however only one biologic – etanercept (Enbrel) - has been approved by the U.S Food and Drug Administration (FDA) for use in children.

Physicians have been prescribing these medications for children “off-label”. This is the practice of prescribing drugs for a purpose outside the scope of the drug’s approved label. Once a drug has been approved for sale for one purpose, physicians are free to prescribe it for any other purpose that in their professional judgment is both safe and effective. They are not limited to its official, FDA-approved indications.

Whether they are prescribed off-label, or the FDA approves additional biologics, the results of several clinical studies were released in 2007 that contributed to determining proper dosing levels, efficacy rates and safety.

One study of infliximab (Remicade) plus methotrexate therapy was conducted on children with polyarticular juvenile rheumatoid arthritis (JRA). The study examined two dosage levels of infliximab, 3 mg/kg and 6 mg/kg. According to the authors of the study, the results showed that the treatment produced an important, rapid and durable clinical effect in children with JDR at one year.
The researchers found that both dosage levels were well tolerated but found the safety level of the 6 mg/kg dosage more favorable than the 3 mg/kg dosage.

Another study was conducted on the long term effects of etanercept on JRA. A controlled clinical trial was completed and many of the original trial participants continued in an open extension of the study. This included 42 participants that continued for 4 years and 26 that continued taking etanercept for eight years beyond the conclusion of the original study. The report concluded that “the drug had a sustainable efficacy profile with a very beneficial safety profile”.

A study of adalimumab (Humira) demonstrated that it was also effective in treating juvenile rheumatoid arthritis. 58% of the participants had at least a 70% improvement in their symptoms after 16 weeks of therapy. This study also had participants continue in an open extension. Those participants continued to experience substantial improvements during an additional 2 years of treatment.

There were two different studies that showed that etanercept and infliximab were both well tolerated and effective in use for children with juvenile spondyloarthropathy.

Etanercept, infliximab, adalimumab and daclizumab (Zenapax), all biologic agents, were studied for use in treating uveitis, a common eye complication associated with JRA. The researchers concluded that all four agents were safe to use in children and that they were effective for treating juvenile uveitis that does not respond to other therapy.