As per a press release on September 28, 2020 tofacitinib (a Janus kinase inhibitor) has received acceptance from the Food and Drug Administration (FDA) for the treatment of active polyarticular course juvenile idiopathic arthritis (pcJIA) in patients aged 2 years and older. This approval was granted on the basis of data from a phase III clinical trial that investigated the safety and efficacy of tofacitinib.

This assessment was performed in participants aged two to 17 years having active rheumatoid factor positive and negative polyarthritis, extended oligoarthritis, and systemic juvenile idiopathic arthritis without systemic manifestations who had an inadequate response or intolerance to at least one disease-modifying antirheumatic therapeutic which could have included methotrexate or biologic therapeutic agents.

Participants having active juvenile psoriatic and enthesitis-related arthritis who had a poor and inadequate response to nonsteroidal anti-inflammatory therapeutics were also included in this analysis. The 44-week, two-part trial comprised of an 18-week, open-label, run-in phase. This was immediately followed by a 26-week, placebo-controlled, double-blind, withdrawal phase.

During the run-in phase, the recruited participants were administered 5 mg tofacitinib (or body weight-based equivalent) twice daily. Of the 225 subjects, approximately 76.9% (N=173) subjects attained juvenile idiopathic arthritis American College of Rheumatology (ACR) 30 response at 18th week. They were randomly allocated into the double-blind phase where they were administered either placebo or tofacitinib therapy.

The disease flare incidence was the major study outcome. It was defined as the deterioration of at least 30% in three or more of the six juvenile idiopathic arthritis core response variables with no more than one of the remaining juvenile idiopathic arthritis core response variables improving by at least 30%, at week 44 relative to the double-blind phase baseline at 18th week.

Compared with placebo, patients treated with tofacitinib therapy witnessed considerably fewer disease flares at week 44, as depicted in the following table: 

The safety profile of tofacitinib displayed consistency with that noted in adult rheumatoid arthritis patients.

Although numerous advanced treatments exist, tofacitinib will be an attractive novel choice given it does not need infusions or injections. Currently, Tofacitinib is supplied as 5 mg and 10 mg tablets. In the first quarter of 2021, an oral solution formulation (tofacitinib 1mg/mL) is anticipated to be available.