Artrofoon (oral ultra-low doses of antibodies to TNF-alpha is a novel drug approved by the Russian Ministry of Health for the treatment of rheumatoid arthritis (RA). The aim of this study was to assess clinical efficacy and safety of artrofoon in RA compared with diclofenac. In a 6-month, randomized, open-label, comparative trial, 60 patients with active RA (eight men and 52 women aged 23 to 62, mean disease duration 10 years) received artrofoon (8 tablets daily, n = 30) or diclofenac (100 mg daily, n = 30). RA signs and symptoms as well as serum levels of inflammatory markers were evaluated before treatment and at months 1, 3 and 6. Most patients in the artrofoon group showed a 20% improvement in major RA symptoms by the end of the study. The clinical effect rose gradually reaching maximum at month 6. In the artrofoon group, 57% of the patients achieved an American College of Rheumatology (ACR) 20% criteria (ACR20) by month 6 versus 20% of those receiving diclofenac. In some patients in the artrofoon arm, serum proinflammatory cytokine levels significantly decreased (> or = 25% reduction). Diclofenac produced a less pronounced clinical effect, and no changes in cytokine profile. Unlike conventional nonsteroidal anti-inflammatory drugs, artrofoon produced no adverse effects and the overall tolerability and safety were excellent. A half-dose treatment with artrofoon (4 tablets daily) was able to sustain clinical improvements over a 6-month follow-up period. To conclude, artrofoon is a safe and effective treatment for rheumatoid arthritis that acts by influencing the inflammatory process.