Subcutaneous administration of polymerized-type I collagen for the treatment of patients with rheumatoid arthritis. An open-label pilot trial.

OBJECTIVE: To determine the efficacy, tolerance and safety of subcutaneous injections of porcine type I collagen-polyvinylpyrrolidone (PVP) in patients with rheumatoid arthritis (RA).

METHODS: Eleven patients with active RA on stable therapy with methotrexate (MTX) were enrolled in a 3 month prospective and longitudinal study. Patients were treated weekly with subcutaneous injections of 0.2 ml of collagen-PVP (1.7 mg of collagen) in the 8 most painful joints. The primary endpoints included the Ritchie index (RI), swollen joint count, disease activity score (DAS), erythrocyte sedimentation rate (ESR), and C-reactive protein (CRP). The secondary endpoints included morning stiffness, pain intensity on a visual analog scale (VAS), and the Spanish-Health Assessment Questionnaire Disability Index (HAQ-DI). Improvement was determined using American College of Rheumatology (ACR) response criteria.

RESULTS: Collagen-PVP was safe and well-tolerated and there were no adverse events. Patients had a statistically significant improvement (p < 0.05) in basal versus 3 month's treatment in morning stiffness (Delta -32.3, -68.6%), RI (Delta -10.2, -46.4%), swollen joint count (Delta -10.7, -71.8%), VAS (Delta -39.9, -63.8%), HAQ-DI (Delta -0.5, -48.5%), DAS (Delta -1.35, -70.5%) and ACR20, 50, and 70 (80.0%; 60.0% and 20.0% respectively). We found no differences in serologic or hematologic variables.

CONCLUSION: Collagen-PVP was a safe and well-tolerated drug for the short term treatment of RA. The combination of collagen-PVP plus MTX was more efficacious than MTX alone. However, double-blind placebo-controlled phase II and III clinical trials are necessary to determine whether this drug could be useful in the longterm treatment of RA.