The study met its primary and key secondary endpoint of Assessment in SpondyloArthritis International Society (ASAS) 20 and 40 response, respectively, versus placebo at week 16.
AS is a chronic, inflammatory disease with symptoms including pain and stiffness in the back and hips. In some patients, it can result in fusion of the vertebrae in the spinal column.
The study enrolled 270 adult patients with AS, who met modified New York Criteria, and had inadequate response or intolerance to two or more nonsteroidal anti-inflammatory drug (NSAID) therapies.
The multi-centre, double-blind, placebo-controlled trial analysed the safety and efficacy of twice-daily tofacitinib 5mg over placebo.
A total of 270 patients were randomly given twice daily tofacitinib 5mg or placebo for 16 weeks.
Eligible participants who completed the 16-week treatment were then given open-label tofacitinib 5mg twice daily for 32 weeks and were followed up for four weeks.
At week 16, 56.4% of patients who received tofacitinib achieved an ASAS20 response, which was significantly greater as compared to 29.4% in the placebo group, meeting the primary endpoint.
Furthermore, the study met its key secondary endpoint, with 40.6% of patients who were given tofacitinib achieved significantly greater ASAS40 response as compared to 12.5% in placebo.
Pfizer Global Product Development Inflammation & Immunology chief development officer Michael Corbo said: “Ankylosing spondylitis is a debilitating condition, and its often progressive nature affects patients for most of their adult lives, limiting physical function and perceived health-related quality of life.
“We are proud to share these positive results from our Phase III investigational study for tofacitinib in adults with ankylosing spondylitis, and we believe they demonstrate Pfizer’s commitment to addressing unmet needs for those living with inflammatory conditions.”
Last month, Pfizer reported positive data from its Phase III trials of its 20vPnC candidate in adults with pneumococcal disease.