medwireNews: The Janus kinase (JAK) inhibitor baricitinib has the potential to be “an important part of the treatment landscape” for juvenile arthritis, reported Athimalaipet Ramanan at ACR Convergence 2022 in Philadelphia, Pennsylvania, USA.
These findings are based on the phase 3 JUVE-BASIS trial, which included 220 patients aged 2–17 years with polyarticular course juvenile idiopathic arthritis (JIA), enthesitis-related arthritis, or juvenile psoriatic arthritis and an inadequate response to at least one conventional or biologic DMARD. Participants were all given once-daily baricitinib (4 mg equivalent dose based on age) for a lead-in period of 12 weeks.
The presenter, from Bristol Royal Hospital for Children in the UK, said that around three-quarters of participants achieved a JIA-ACR30 response during weeks 1–12, and these 163 children entered the double-blind withdrawal period, in which they were randomly assigned to continue with baricitinib or switch to placebo until flare or for a maximum of 32 weeks. Additionally, JIA-ACR50, 70, and 90 responses at week 12 were achieved by 63.5%, 46.1%, and 20.1% of patients, respectively.
The investigators found that the trial’s primary endpoint of time to disease flare from randomization was significantly longer among participants who continued with baricitinib than among those given placebo, at a median of unreached versus 27.1 weeks (hazard ratio=0.24).
Children in the baricitinib arm were also significantly less likely to experience flare during the 32-week withdrawal period than those in the placebo group, with rates of 17.1% and 50.6%, respectively.
Ramanan told delegates that the safety profile of baricitinib in the JUVE-BASIS trial was consistent with that seen in adults. Treatment-emergent adverse events (TEAEs) during the double-blind withdrawal period occurred in 65.9% of patients in the baricitinib arm and 46.9% of those given placebo, most commonly upper respiratory tract infections (11.0 vs 1.2%) and headache (11.0 vs 3.7%).
“We know from data of [JAK inhibitors] in adults that herpes zoster infections are a real cause for concern,” said the presenter. In the JUVE-BASIS trial, there was one case of herpes virus infection and one case of herpes zoster during baricitinib treatment in the 12-week lead-in period, and one case of herpes virus infection in the placebo arm during the double-blind withdrawal period.
He also pointed out that thromboembolic events and major adverse cardiovascular events “are a source of huge concern” with JAK inhibitors in adult populations with cardiovascular risk factors, as demonstrated in the ORAL Surveillance trial.
“Generally those are not risk factors which are really applicable to our patient population, nor is thromboembolism,” said Ramanan, but he pointed out that there was one case of pulmonary embolism during baricitinib treatment in JUVE-BASIS.
“We have to bear in mind as pediatricians [that] these trials only demonstrate short-term safety,” and long-term safety data are needed, he cautioned.
Overall, the JUVE-BASIS results “support baricitinib as a treatment for signs and symptoms of JIA,” said Ramanan, noting that its oral route of administration is “more palatable to the children and families of children with juvenile arthritis” than other treatment options.
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