A phase I/II randomized, controlled, clinical trial for assessment of the efficacy and safety of β-D-mannuronic acid in rheumatoid arthritis patients.

Background: Following the potent efficacy of β-D-mannuronic acid (M2000) in phase I/II trial in ankylosing spondylitis patients, the present clinical trial was conducted to evaluate the efficacy, safety, and tolerability of this novel drug in rheumatoid arthritis (RA) patients who had inadequate response to conventional therapy.

Method: The study was a 12-week randomized, controlled, phase I/II clinical trial with two treatment arms: M2000 and conventional treatment. Patients who had RA according to the modified American College of Rheumatology (ACR) criteria, with active disease at baseline also inadequate response to conventional therapy, were enrolled in this study. M2000 was administrated at a dose of two capsules (500 mg) per day orally during a period of 12 weeks. The primary endpoint was the proportion of patients fulfilling the ACR 20% improvement criteria after 12 weeks of M2000 therapy. Moreover, the patients were also followed up for safety.

Results: There were no statistically significant differences between treatment and conventional groups at baseline characteristics. The ACR20 response rate was significantly higher among M2000-treated patients than conventional-treated control, so that 74% of patients in treatment group showed an ACR20 response after 12 weeks of M2000 therapy (74 versus 16%; P = 0.011). 10% of M2000-treated patients and 57.1% of conventional-treated patient's adverse events occurred during this study.

Conclusion: Treatment with M2000 in combination with conventional therapy showed a significantly superior efficacy along with a high safety profile compared to conventional-treated patients. Thereby, M2000 might be suggested as a suitable option in the treatment of RA.