Tofacitinib is Effective in the Treatment of Ankylosing spondylitis

Tofacitinib is an oral Janus kinase inhibitor for the treatment of rheumatoid arthritis, psoriatic arthritis, ulcerative colitis and polyarticular course juvenile idiopathic arthritis. As phase 2 study showed promising results with tofacitinib in the treatment of AS, Dr Atul Deodhar and his team conducted a phase 3 trial to assess the efficacy/safety of tofacitinib in adult patients with active ankylosing spondylitis.

It was a phase III, randomized, double-blind, placebo-controlled study of 269 patients with active AS. The patients were randomized to receive either tofacitinib 5 mg two times per day, n=133 or placebo, n=136for 16 weeks. After week 16, all patients received open-label tofacitinib until week 48. The major outcome assessed was Assessment of SpondyloArthritis international Society ≥20% improvement (ASAS20) and ≥40% improvement (ASAS40) responses, respectively, at week 16. The researchers also assessed the safety outcomes throughout the study.

Key findings of the study were:

• By week 16, the researchers noted that the patients who received tofacitinib had a significantly higher ASAS20 response rate than placebo (56.4% vs 29.4%).
• Similarly, they found that the ASAS40 response rate was significantly greater with tofacitinib (40.6%) than placebo (12.5%).
• The proportions of participants with adverse events up to week 16 were 54.9% and 51.5% for the tofacitinib and placebo groups, respectively. The rates for serious adverse events during this time were 1.5% and 0.7%, respectively.
• By week 48, they noted that 2.3% of patients who received tofacitinib demonstrated adjudicated hepatic events, while 2.3% developed non-serious herpes zoster and 0.8% experienced a serious infection.
• However, they reported no deaths, malignancies, major adverse cardiovascular events, thromboembolic events or opportunistic infections.

The authors concluded, "in this phase III study, patients with active AS --had a rapid, sustained and clinically meaningful response to tofacitinib 5 mg two times per day, with no new potential safety risks identified. This suggests a favourable benefit-risk balance in patients with active AS treated with tofacitinib."

For further information:

doi: 10.1136/annrheumdis-2020-219601