Study objective: To assess the safety and efficacy of amiprilose hydrochloride (HCl), a novel synthetic carbohydrate with anti-inflammatory and immunomodulatory properties, in patients with rheumatoid arthritis.
Design: Prospective, multicenter, randomized, parallel group, double-blind placebo-controlled 12-week trial.
Patients: Two hundred and one functional class I and II patients with definite or classic rheumatoid arthritis, previously untreated with disease modifying antirheumatic drugs.
Interventions: Patients were withdrawn from nonsteroidal anti-inflammatory drug therapy. Those who flared were randomly assigned to amiprilose HCl, 6 g/d, or placebo for 12 weeks. No concomitant anti-inflammatory or antirheumatic drug therapy was permitted during the study. Combination acetaminophen and propoxyphene napsylate was the only supplemental analgesic medication allowed.
Measurements and main results: The number of painful joints and swollen joints, joint pain and joint swelling indices, left and right grip strength, investigator global assessment, and patient global assessment returned to baseline for the amiprilose group and showed statistically significant (P less than 0.05) differences from the placebo group within 4 to 6 weeks. The protocol criteria for overall therapeutic response were satisfied by 41% of the amiprilose patients, compared with 21% of the placebo group (P = 0.003). Approximately 0.5 tablet per day less analgesic medication was taken by the amiprilose group (P less than 0.05 at weeks 6 and 12). There were no statistically significant differences in morning stiffness, walking time, erythrocyte sedimentation rate, C-reactive protein, or rheumatoid factor between the groups. A similar number of adverse experiences were reported by the patients on amiprilose (67%) and on placebo (63%). One patient on amiprilose developed thrombocytopenia of unknown cause; no other reported adverse effects were serious.
Conclusions: Amiprilose HCl has significant anti-inflammatory activity and a favorable safety profile when used as the sole antirheumatic therapy in patients with active rheumatoid arthritis. Synthetic carbohydrates may represent an important new class of drugs for the treatment of inflammatory, autoimmune diseases.