Arthritis News – 1999

Furst et al (J Rheum 26:8, 1999) recently published the results of a pilot study which suggest that extracorporeal staph protein A therapy (Prosorba) may play a role in the management of moderate to severe rheumatoid arthritis (RA). Fifteen patients with RA were enrolled in the study. These patients fulfilled the ACR criteria for RA, failed to respond to at least 2 disease modifying antirheumatic drugs (DMARDs), and had active disease after DMARD washout. Patients received apheresis across the Staph A protein column weekly for 12 weeks. Plasma was separated from cellular elements and perfused through the Prosorba column, then the cellular elements were recombined with the plasma and returned to the patient. Evaluations were performed at weeks 2, 4, 8, and 12 after the final treatment using the > 20% and > 50% Paulus criteria.

67% of the patients (7/15) showed measurable improvement based on > 50% Paulus criteria in painful joint count, swollen joint count, erythrocyte sedimentation rate (ESR) and patient and physician global assessments 4 weeks post final treatment and 67% met the > 20% Paulus criteria for this same timepoint. Ten weeks following start of treatments was the average timepoint for an initial, sustained response. The most common side effect resulting from the treatments were joint pain and swelling and fatigue of short duration.

Editorial comment: This was an unblinded open label protocol primarily to assess safety of the column in RA. While the efficacy data are encouraging, the results of a double-blinded protocol with larger numbers of patients will be more definitive.