Lack of efficacy of oral bovine type II collagen added to existing therapy in rheumatoid arthritis

McKown KM, Carbone LD, Kaplan SB, Kang AH, Postlethwaite AE · Arthritis and Rheumatism

Null, and slightly worse than null. ACR20 response was 16.84% on collagen against 20.0% on placebo, and the paper notes significant differences in several clinical variables after treatment 'all favoring the placebo group'. The title states the conclusion.

Population

Patients with active rheumatoid arthritis continuing their existing medications

Intervention

Oral bovine type II collagen, 0.1 mg/day for 1 month then 0.5 mg/day for 5 months

Comparator

Placebo

Limitations

Add-on design against existing therapy, which can mask a modest independent effect. Doses were at the low end tested by Barnett.