The safety profile of Humira (adalimumab) in children with polyarticular juvenile idiopathic arthritis (pJIA), enthesitis-related arthritis, and Crohn’s disease is similar to that in adults, a large analysis of multiple clinical trials shows.

The study, “Safety of Adalimumab in Pediatric Patients with Polyarticular Juvenile Idiopathic Arthritis, Enthesitis-Related Arthritis, Psoriasis, and Crohn’s Disease,” was published in The Journal of Pediatrics.

Humira, manufactured by AbbVie, is a biological therapy approved in the U.S. and Europe for the treatment of moderately to severely active pJIA, in patients ages 2 or older. The therapy is also approved for patients ages 6 or older with moderate to severe active Crohn’s disease, one of the two most common forms of inflammatory bowel disease (IBD), characterized by chronic inflammation of the gastrointestinal tract.

Humira is an antibody that works by blocking the action of a cytokine called the tumor necrosis factor, or TNF. Immune cells produce TNF, a protein that promotes inflammatory response, as part of the normal immune response process.

In juvenile idiopathic arthritis, the levels of TNF in affected joints are increased, leading to joint inflammation.

The overall safety profile of Humira has already been established in adults. Its safety is consistent with that of other anti-TNF agents, even when the treatment lasts for almost 12 years.

However, “pediatric safety data for adalimumab remain limited relative to adult safety data,” the researchers wrote.

Since Humira is under evaluation for different pediatric diseases — pJIA, Crohn’s disease, and psoriasis (an inflammatory skin disease) — researchers decided to assess the therapy’s safety in these young patients.

The team analyzed the safety findings from seven trials testing Humira, administered under the skin (subcutaneously), in pediatric patients with pJIA (NCT00048542, NCT00775437, NCT00690573); enthesitis-related arthritis (NCT01166282); psoriasis (NCT01251614); and Crohn’s disease (NCT00409682 and the trial’s open-label extension, NCT00686374). All trials were sponsored by AbbVie.

Researchers analyzed the occurrence of adverse events following the first dose of adalimumab, and up to 70 days after the last dose.

The analysis included 577 pediatric patients — 274 with JIA, 111 with psoriasis, and 192 with Crohn’s disease.

Across the three different diseases, the most commonly reported adverse events included upper respiratory tract infections (27%), nasopharyngitis (24%), and headaches (24%).

In JIA patients, the most commonly reported side effect was injection-site pain (22% of patients). Headaches were most frequent in psoriasis patients (30%), and Crohn’s patients most commonly reported a worsening of their disease (55%).

Site reactions to Humira injections were reported in 37% of patients with JIA, 22% of Crohn’s disease patients, and 10% of those with psoriasis.

Serious adverse events were detected in almost one-third (29%) of all patients, the most common being serious infections, such as pneumonia, which was the most frequently reported, affecting 1% of all patients. Those who received accompanying therapy with corticosteroids had more adverse events and higher rates of infections than those without it, the only exception being psoriasis patients.

“The current analysis adds to a more complete understanding of the established safety profile of adalimumab and demonstrated that in pediatric patients with pJIA, ERA [enthesitis-related arthritis], psoriasis, and CD [Crohn’s disease], the overall safety profile was comparable and consistent with that in adults,” the team concluded.