Positive results have been reported from a phase 3 study investigating tofacitinib (Xeljanz, Pfizer) for the treatment of patients with psoriatic arthritis (PsA). The study evaluated the efficacy and safety of tofacitinib 5 mg and 10 mg twice daily (BID) in adults with active PsA who had shown an inadequate response to at least one conventional synthetic disease-modifying antirheumatic drug (csDMARD) and who were tumor necrosis factor inhibitor (TNFi)-naïve. The trial met its primary efficacy endpoints, demonstrating that both the 5-mg BID and 10-mg BID regimens were superior to placebo at three months, as measured by the American College of Rheumatology 20 (ACR20) response criteria and by the Health Assessment Questionnaire Disability Index (HAQ-DI) score.
Tofacitinib is a Janus kinase (JAK) inhibitor. It is the only once-daily oral JAK inhibitor approved for the treatment of patients with moderate-to-severe rheumatoid arthritis.
The OPAL Broaden trial investigated the efficacy and safety of tofacitinib 5 mg and 10 mg BID in treating the signs and symptoms of PsA, and the improvement in physical function in patients with active PsA who had shown an inadequate response to at least one csDMARD because of the lack of efficacy or an adverse event, and who were TNFi-naïve. Patients enrolled in the study were required to be receiving one csDMARD as background therapy and to continue that dose for the duration of the study. The study also included subcutaneous adalimumab (40 mg administered every two weeks) as an active control arm. However, the study was not powered for noninferiority or superiority comparisons between tofacitinib and adalimumab.
A total of 422 patients were randomly assigned to the following treatment arms: tofacitinib 5 mg BID; tofacitinib 10 mg BID; adalimumab 40 mg twice weekly; placebo to tofacitinib 5 mg BID treatment sequence; and placebo to tofacitinib 10 mg BID treatment sequence.
All of the treatment groups had similar rates of treatment-emergent adverse events, serious adverse events, and discontinuations due to adverse events during the 12-month study.
PsA is a chronic inflammatory multisystem disease. The symptoms of PsA often overlap with skin inflammation, as observed in psoriasis and other forms of inflammatory arthritis, including pain and swelling of the joints; inflammation of the sites where tendons or ligaments insert into the bone; inflammation of the spine; reduced range of motion; and inflammation of the fingers and toes. Up to 30% of people with psoriasis may develop PsA. An estimated 3 million people in the U.S. and Europe have the disease.
Source: Pfizer; April 5, 2016.