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.
To assess the safety, tolerability and clinical effects of MM-093 during a 12-week, randomised, double-blind, placebo-controlled study.
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.
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.
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.