Arthritis News – 1999
The U.S. Food and Drug Administration (FDA) has approved the Prosorba column for use in patients with long-term, moderate to severe rheumatoid arthritis who have failed or are intolerant to DMARDs.
Utilizing a two-hour outpatient apheresis treatment, the Prosorba column is administered once a week for twelve weeks. The column is a staphylococcus protein A immunoadsorption column which has been approved for the use in Idiopathic Thrombocytopenic Purpura (ITP) since 1987.
In a randomized, multi-center, double-blind Phase III clinical trial, 109 patients given either 12 weekly Prosorba treatments or sham treatments. Patients were assessed using the American College of Rheumatology 20% criteria at week 20. (Definition of Improvement in RA trials) 41.7% of those patients receiving Prosorba vs. 15.6% receiving placebo showed improvement following the 12 treatments. In this same group, Prosorba responders showed a decrease in tender joint count of 65.5% and a decrease in swollen joint counts of 60.7% at week 20.
Editorial Comment: These results are interesting and encouraging. Clinical efficacy of Prosorba in RA needs to be validated in larger controlled studies. The mechanism of action of Prosorba in RA is not known.