WEDNESDAY, Aug. 8 (HealthDay News) -- For patients with rheumatoid arthritis, a novel oral Janus kinase inhibitor, tofacitinib, is associated with reduced symptoms when used as monotherapy or in addition to background methotrexate, according to two phase 3 studies published in the Aug. 9 issue of the New England Journal of Medicine.

Roy Fleischmann, M.D., from the Metroplex Clinical Research Center in Dallas, and colleagues conducted a study involving 611 patients to examine the role of tofacitinib monotherapy in rheumatoid arthritis. Participants were assigned in a 4:4:1:1 ratio to receive 5 mg tofacitinib twice daily, 10 mg tofacitinib twice daily, or to one of two placebo groups with placebo for three months followed by 5 mg or 10 mg of tofacitinib twice daily. The researchers found that, at month three, a higher percentage of patients in the tofacitinib groups met the criteria for a 20 percent improvement in the American College of Rheumatology scale (ACR 20) compared with placebo (59.8 percent in the 5-mg tofacitinib group and 65.7 in the 10-mg tofacitinib group versus 26.7 in the combined placebo groups).

Ronald F. van Vollenhoven, M.D., from the Karolinska Institute in Stockholm, and colleagues conducted a randomized trial in which 717 patients with rheumatoid arthritis who were receiving stable doses of methotrexate were randomly assigned to tofacitinib (5 or 10 mg twice daily), adalimumab, or placebo. At month six the researchers found that the ACR 20 response rates were 51.5 and 52.6 percent for those receiving 5 and 10 mg tofacitinib, respectively, compared with 47.2 and 28.3 percent for those receiving adalimumab and placebo, respectively.

"In patients with rheumatoid arthritis receiving background methotrexate, tofacitinib was significantly superior to placebo and was numerically similar to adalimumab in efficacy," van Vollenhoven and colleagues write.

Several authors of the first study disclosed financial ties to pharmaceutical companies, including Pfizer; several authors of the second study are employees of Pfizer, which funded both studies and manufactures tofacitinib.

Full Text - Fleishmann (subscription or payment may be required)
Full Text - van Vollenhoven (subscription or payment may be required)
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