Immunoadsorption for the treatment of rheumatoid arthritis: final results of a randomized trial. Prosorba Trial Investigators.

A double-blind, randomized, placebo controlled study was conducted to determine the efficacy of a promising immunoadsorption treatment device containing staphylococcal protein A (Prosorba Immunoadsorption Column, Cypress Bioscience, Inc., San Diego, CA, U.S.A.) in patients with refractory rheumatoid arthritis (RA). Eligibility criteria required adult RA patients who had failed either methotrexate or 2 other disease modifying antirheumatic drugs (DMARD) and who had predefined active disease. All disease-modifying agents were discontinued at least 30 days prior to entry. Patients received 12 weekly procedures after being randomized to the active treatment arm or to the sham treatment arm (apheresis only). Evaluations were double-blinded and occurred at baseline and periodically for 24 weeks thereafter. Primary efficacy was assessed at 7 and 8 weeks after the completion of 12 treatments (at trial Weeks 19 and 20) using the American College of Rheumatology (ACR) definition of improvement (1,2), and results from the assessments at Weeks 19 and 20 were averaged. Ninety-nine randomized patients had a mean disease duration of 15.4 years and received an average of greater than 5 DMARD regimens prior to entry. Analysis of patients who completed all treatments and follow-up indicated that 15 of 36 (41.7%) column-treated patients responded compared to 5 of 32 (15.6%) sham-treated patients (p < or = 0.003). Intent to treat analysis of all patients who were randomized in the study indicated 15 of 52 (28.9%) column-treated patients responded compared to only 5 of 47 (10.6%) patients who received sham treatments (p = .005). Common adverse events (AEs) included joint pain, fatigue, joint swelling, and hypotension. Central line usage was clearly associated with significant AEs during this trial and is not recommended. Hemoglobin, hematocrit, and mean corpuscular volume values decreased similarly in both treatment arms, attributed to phlebotomy for laboratory and scientific studies and to small, repetitive (normal) apheresis losses. Other AEs such as nausea, rash, pruritus, flushing, and fever occurred in 1 to 6% of treatments in each arm (NS). There was no significant increase in AEs in column-treated patients compared to sham-treated patients. Protein A immunoadsorption was proven to be a new therapeutic alternative in patients with severe, refractory disease.