Drug Survival Rates in Pediatric Patients With HS Compared

The drug survival for adalimumab is significantly higher than that of infliximab in pediatric patients with hidradenitis suppurativa (HS), results from a small single-center study showed.

A previous study found that overall drug survival of adalimumab and infliximab in adults with HS at 12 and 24 months was 56.3% and 30.5%, and 58.3% and 48.6%, respectively. “They also found that older age, longer disease duration, higher body mass index (BMI), and surgery during treatment are associated with increased drug survival,” Robyn Guo, a third-year medical student at Duke University, Durham, North Carolina, told this news organization following the annual Symposium on Hidradenitis Suppurativa Advances, where the study was presented during an oral abstract session. “To our knowledge, the drug survival of biologic therapies in pediatric HS patients has not been previously investigated.”

Adalimumab and infliximab are tumor necrosis factor blockers approved for multiple indications; adalimumab is approved for treating moderate to severe HS in patients aged 12 years or older. Infliximab is not approved for HS but is used to treat the disease.

To determine the drug survival of adalimumab and infliximab in pediatric patients with HS and whether patient comorbidities and HS lesion location are associated with length of biologic survival in pediatric patients with HS, Guo and colleagues used Kaplan-Meier survival curves to calculate biologic survival at 12 and 24 months following biologic initiation and Cox proportional hazards regression to analyze potential factors associated with biologic survival. The study population included 49 pediatric patients in the adalimumab cohort and 11 in the infliximab cohort.

The researchers found that drug survival for adalimumab was 90.6% at 12 months (95% CI, 83.0%-98.8%) and 78.3% at 24 months (95% CI, 67.7%-90.6%), while drug survival for infliximab was 54.5% at 12 months (95% CI, 31.8%-93.6%) and 36.4% at 24 months, an overall difference that reached statistical significance (P = .0009). “Our data suggests that adalimumab survival is significantly higher than infliximab survival in pediatric HS patients,” Guo said.

On univariate Cox regression analysis, gluteal HS lesions were associated with shorter adalimumab survival, and obesity was associated with longer infliximab survival.

The researchers acknowledged certain limitations of their study, including the small sample size and that unadjusted Cox regression analysis did not account for baseline HS severity, biologic therapy dosing, and concomitant medication use. Also, there were patients in both cohorts who were not biologic-naive: Two in the adalimumab cohort were previously treated with infliximab, and five patients in the infliximab cohort were previously treated with adalimumab.

“We plan on conducting further analysis using adjusted Cox regression analysis to account for baseline disease severity measured by Hurley stage, BMI, medication dosing, and concomitant medication use,” Guo said.

The researchers reported having no financial disclosures.