Long-term Data on Anakinra Support Its Efficacy Against RA

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Long-term Data on Anakinra Support Its Efficacy Against Rheumatoid Arthritis

Arthritis Rheum 2002;46:2838-2845.

http://www.medscape.com/

NEW YORK (Reuters Health) Dec 11 - The interleukin-1 receptor antagonist anakinra (Kineret) "has now been shown to maintain clinical benefits for up to 48 weeks and to have a good safety profile over 76 weeks" in patients with active rheumatoid arthritis, according to principal investigator Dr. Nuki.

Anakinra (Kineret; Amgen), which is injected subcutaneously by the patient daily, had previously been shown "to have modest clinical efficacy and to slow radiological progression of disease in a randomized controlled double-blind trial in patients with rheumatoid arthritis over 24 weeks," Dr. Nuki--now an emeritus professor at the University of Edinburgh--noted in comments to Reuters Health.

In a 52-week extension phase, his team studied 309 of the 345 patients who completed the original study. Patients who received placebo during the first 24 weeks of the trial were randomized to 30, 75 or 150 mg/day of anakinra, according to the team's report in the November issue of Arthritis and Rheumatism. The others continued on whatever dosage they had been using.

Improvements observed during the first 24 weeks were maintained during an additional 24 weeks of treatment, the investigators determined. At week 48, a total of 42% of the patients continuing on anakinra demonstrated a sustained 20% response according to American College of Rheumatology criteria (ACR20), similar to the 36% who had done so at week 24 (p = 0.118).

In the group that switched from placebo to anakinra, a sustained ACR20 response was noted in 40%, up from 15% after 24 weeks on placebo (p < 0.001).

The extension trial also evaluated the safety of anakinra through week 76. Mild, localized injection site reactions were the most common adverse events, and the withdrawal rate was similar for placebo and the three active dosages. Four patients withdrew because of infection and five because of leukopenia, but anakinra was not linked to serious infection, malignancy or bone marrow suppression.

Dr. Nuki noted that anakinra is the first biological agent available that is specifically directed against interleukin-1. As such, he said, it "can be tried for patients with active rheumatoid arthritis who have not responded to, or not tolerated, other disease-modifying antirheumatic drugs or anti-TNF agents."