Phase 3 Results Boost Rheumatoid Arthritis Drug

(National Institutes of Health)

Results from a Phase 3 clinical trial show the drug tasocitinib made by Pfizer Inc. in New York, New York met two out of three end-points for treating rheumatoid arthritis (RA). Tasocitinib is an oral Janus kinase inhibitor for treating RA that targets the intracellular signaling pathways operating as hubs in the inflammatory cytokine network.

Tasocitinib, administered as a monotherapy in the trial, met two primary end-points, demonstrating a statistically significant reduction in signs and symptoms of moderately to severely active RA and improvement in physical function, versus placebo at three months. For the third end-point, a measure of disease remission, treatment with tasocitinib resulted in a numerically greater, but not statistically significant difference from a placebo.

The trial, according to Pfizer, revealed similar frequencies of adverse events (AEs) across all treatment groups. For all patients, the most frequent AEs were bronchitis, upper respiratory infection, and urinary tract infection. No new safety signals were detected.

The trial was a six-month, double-blind, placebo-controlled study of 611 randomized patients. Patients with moderately to severely active RA who had an inadequate response to at least one disease-modifying antirheumatic drug received tasocitinib in doses of 5 mg or 10 mg, or placebo, twice a day. After three months of treatment, patients randomized to the placebo group began receiving tasocitinib 5 mg or 10 mg in a blinded manner.

Rheumatoid arthritis is a chronic inflammatory disorder that most typically affects the small joints in hands and feet. Unlike the wear-and-tear damage of osteoarthritis, rheumatoid arthritis affects the lining of joints, causing a painful swelling that can eventually result in bone erosion and joint deformity.

Related: Clinical Trial Shows Results for Rheumatoid Arthritis Drug

*     *     *