First JAK inhibitor approved for patients 2 years and older with active polyarticular disease course

The FDA approved two formulations of tofacitinib (Xeljanz) to treat kids 2 years and older with active polyarticular course juvenile idiopathic arthritis (pcJIA), making it the first Janus kinase (JAK) inhibitor approved for this indication.

Tofacitinib, which was previously approved to treat adults with rheumatoid arthritis, psoriatic arthritis, and ulcerative colitis, is now approved for pcJIA in two forms, a tablet and an oral solution, and dosage is based upon the weight of the patient.

This new indication for tofacitinib was based on results from a phase III trial that occurred in two phases — an 18-week open-label, run-in phase involving 225 patients and a 26-week double-blind, placebo-controlled, randomized, withdrawal phase involving 173 patients — for a total duration of 44 weeks.

“The study evaluated the efficacy and safety of tofacitinib taken as either a 5 mg tablet or as a 1 mg/mL oral solution twice daily based on the subject’s body weight (<40 kg for the oral solution) and/or patient preference,” wrote the drug’s manufacturer, Pfizer Inc., in a company press release. “The trial met its primary endpoint showing that in patients with pcJIA who achieved a juvenile idiopathic arthritis (JIA) American College of Rheumatology (ACR) 30 response at the end of the run-in phase, the occurrence of disease flare in patients treated with tofacitinib (31 percent; n/N=27/88) was statistically significantly (P=0.0007) lower than patients treated with placebo (55 percent; n/N=47/85) at week 44. In this study, disease flare was defined as a 30 percent or more worsening in at least three of the six variables of the JIA ACR core set, with no more than one of the remaining JIA core response variables improving by 30 percent or more (outcome measures used in JIA clinical trials) after randomization.”

Adverse drug reactions in patients with pcJIA were consistent with reactions seen in adult rheumatoid arthritis patients, the manufacturer noted.

Tofacitinib carries several Boxed Warnings stating that patients taking the drug are at increased risk for developing serious, potentially deadly infections, lymphoma and other malignancies—including an increased rate of Epstein Barr Virus-associated post-transplant lymphoproliferative disorder—and thrombosis, including pulmonary embolism, deep venous thrombosis, and arterial thrombosis. The most common side effects experienced in patients with rheumatoid arthritis included upper respiratory tract infection, nasopharyngitis, diarrhea, headache, and hypertension.

Tofacitinib oral solution is expected to be available by the end of Q1 in 2021, the drug’s manufacturer explained; the tablet formulation is available immediately.

John McKenna, Associate Editor, BreakingMED™

Cat ID: 138

Topic ID: 85,138,730,138,192,725,158,68,925