The preliminary phase II results for Rabeximod demonstrate a positive therapeutic effect on patients with rheumatoid arthritis. Rabeximod is an orally administered disease-modifying anti-rheumatic drug (DMARD) for the treatment of moderate or severe active rheumatoid arthritis that is first in class. The primary endpoint of the study was to show the effect of Rabeximod at 12 weeks. 224 patients participated and treatment was given during the 12 weeks with clinical follow-up visits through week 16. Patients, all on methotrexate, were randomized to either Rabeximod 6.25mg, 15mg, 37.5 mg, or placebo. Professor Lars Klareskog of the University Hospital in Stockholm, Sweden is the Principal Investigator.

The efficacy data are positive for Rabeximod; however, the results show that the treatment duration of 12 weeks is not long enough to reach an optimal clinical effect in combination with methotrexate. The therapeutic effect of the regimen was seen at 16 weeks; whereby, the 15mg dose group showed statistically significant effects for seven of the key secondary endpoints of treatment, i.e., ACR20, DAS28, patient global assessment, physician global assessment, swollen joint count, and tender joint count. The study also found that Rabeximod has a good safety profile and showed similar incidences of adverse effects as that of the placebo group.

Rabeximod is currently under development by OxyPharma, a Swedish drug company that is developing new drugs primarily in the areas of rheumatoid arthritis and multiple sclerosis.