Background: Rheumatoid arthritis (RA) tends to remit during pregnancy, with more patients achieving remission in the third trimester, coinciding with an increase in levels of alpha-fetoprotein (AFP). In vitro and animal studies have shown that AFP has immunomodulatory properties. MM-093 is a non-glycosylated, recombinant version of human AFP.
Objective: To assess the safety, tolerability and clinical effects of MM-093 during a 12-week, randomised, double-blind, placebo-controlled study.
Methods: 12 patients with RA, who had active disease and were on stable doses of methotrexate, received weekly subcutaneous injections of placebo or 21 mg of MM-093. Assessments were carried out at baseline and weekly thereafter.
Results: Baseline characteristics were similar in both groups. There was one dropout in the placebo group, due to flare of disease. Treatment with MM-093 was well tolerated. No serious adverse event was observed. By day 85, MM-093 produced a significant mean improvement from baseline in Disease Activity Score 28 (DAS28; 0.913 vs 0.008, p = 0.033) and patient's global assessment (28.9% vs -36.3%, p = 0.02) compared with placebo.
Conclusion: This is the first randomised, controlled trial of MM-093, a recombinant version of human AFP, in patients with RA. MM-093 was well tolerated. Evidence of efficacy was observed, suggesting that MM-093 may have therapeutic potential in RA.