Newer Biologic Psoriasis Drugs Don't Boost Infection Risk in Kids

By Lisa Rapaport

March 16, 2020

(Reuters Health) - In children with moderate to severe psoriasis, treatment with systemic immunomodulating drugs, including newer biologics, doesn't appear to increase the risk for infection, a new study suggests.

Researchers examined insurance claims data for 57,323 pediatric patients with psoriasis that had not responded to topical medications, to examine the infection risk within six months of initiating systemic treatment or phototherapy.

After 1:1 propensity score matching, they looked at infection risk among four cohorts of kids: 669 pairs who took either biologic or non-biologic immune-modulators; 681 pairs who took biologics or phototherapy; 909 pairs who got non-biologic immune-modulators or phototherapy; and 49,809 pairs in which a child with psoriasis was matched with a control subject without psoriasis.

Children with psoriasis had an 84% higher six-month risk of serious infections than kids without psoriasis, the study found.

However, there wasn't a significant difference in the risk of infections among children treated with biologics, non-biologics, or phototherapy.

The six-month infection risk was 4.2 per 1,000 patient years for biologics; 5.1 per 1,000 patient-years for non-biologics; and 1.1 per 1,000 patient years with phototherapy.

The relative risk of infection with biologics versus non-biologics was 0.67, compared with 1.5 for biologics versus phototherapy and 5.0 for non-biologics versus phototherapy, researchers report in the Journal of the American Academy of Dermatology.

"Our study demonstrates that at baseline, children with psoriasis seem to carry a nearly two-fold increase in the risk of infection based on the presence of psoriasis alone," said senior study author Dr. Joseph Merola of Brigham and Women's Hospital and Harvard Medical School in Boston.

"The key question for us was to better understand if some of the newer, targeted, biologic medications changed the risk of serious infections among children," Merola said by email. "Demonstrating their relative safety is crucially important to our understanding of how these fit into the treatment algorithm of younger patients suffering with psoriatic disease."

While systemic immune-modulatory agents have significantly improved outcomes in the treatment of moderate to severe psoriasis in children, the infection risks with different treatment options has been less clear, the study team notes. Some studies in adults have found an increased infection risk with certain biologic immune-modulatory agents, but results have been mixed.

Only a handful of children got infections in the study, making it possible that a larger study might be required to detect small but meaningful difference between treatment options.

The comparison of both non-biologics and biologics against phototherapy, for example, showed a higher number of infections but the results weren't statistically significant.

The study was also too short to determine long-term outcomes for kids, said Dr. Joel M. Gelfand, director of the Psoriasis and Phototherapy Treatment Center at the University of Pennsylvania Perelman School of Medicine in Philadelphia.

"The study only followed patients on their treatment for just 6 months, when in reality, children may need to be on these treatments for many years," Gelfand, who wasn't involved in the study, said by email.

"The study also likely did not have adequate information regarding confounding factors," Gelfand added. "For example, the frequency of obesity was very low, suggesting an inability to fully capture important confounding variables."

Still, the study reinforces that systemic medications, which can markedly improve moderate and severe pediatric and adolescent psoriasis, have low associated rates of serious infections, said Dr. Lawrence Eichenfield, a professor of dermatology and pediatrics at the University of California, San Diego, who wasn't involved in the study.

The results should help clinicians and families feel more comfortable using systemic medications, Eichenfield said by email.

Prior to this study, much of clinicians' understanding of infection risk with these drugs was based on what happened with adults, not kids, said Dr. Steve Xu an assistant professor of pediatrics and dermatology at the Northwestern University Feinberg School of Medicine in Chicago who wasn't involved in the study.

"As dermatologists, we really want to offer these systemic treatments that make a profound difference in psoriasis for kids," Xu said by email.

"But, infection risk is always a major concern," Xu added. "In our counseling with parents, we can now use this study to explain the real risk to them."

SOURCE: Journal of the American Academy of Dermatology, online March 3, 2020.