Therapeutic efficacy and safety of chaperonin 10 in patients with rheumatoid arthritis: a double-blind randomised trial

Background Chaperonin 10 (heat shock protein 10, XToll(TM)) has anti-inflammatory properties related to the inhibition of Toll-like receptor signalling pathways. Our aim was to establish whether chaperonin 10 is safe and effective in the treatment of rheumatoid arthritis. Methods in this randomised, double-blind, multicentre study, 23 patients with moderate to severe active rheumatoid arthritis receiving disease-modifying antirheumatic drugs were randomly allocated to three treatment groups receiving intravenous chaperonin 10 twice weekly for 12 weeks at doses of 5 mg (n=8), 7.5 mg (8), or 10 mg (7). The primary outcomes were change in disease activity score (DAS28) and improvement of core disease measures (American College of Rheumatology response score) from baseline to week 12. All analyses were done by intention to treat. This study is registered with the Australian Clinical Trials Registry, number ACTRNO12606000041550. Findings Primary endpoint measures improved from day 14 in all groups and continued to improve to day 84. By end of study, a 20% improvement of core disease measures was seen in six (86%, 95% Cl 43-100), a 50% improvement in four (57%, 14-86), and a 70% improvement in two (29%, 0-57) patients given the highest dose of chaperonin 10. Clinical remission (as defined by a DAS28 <2.6) was achieved in three (13%) of 23 patients. Three individuals dropped out during the study: one in the 5 mg group (rheumatoid arthritis not controlled), one in the 7.5 mg group (adverse event), and one in the 10 mg group (lost to follow-up). The most common adverse events were exacerbation of rheumatoid arthritis (both during and after the study) and upper respiratory tract infection. Only one adverse event was judged to be of severe intensity. Interpretation Chaperonin 10 seems to be well tolerated and efficacious in treatment of the symptoms of rheumatoid arthritis, at least in the short term.