A Comparison of Psoriasis Severity in Pediatric Patients Treated With Methotrexate vs Biologic Agents

This cohort study compares the use of methotrexate vs biologic agents in children with moderate to severe psoriasis. Question What is the association between use of methotrexate vs biologics and psoriasis severity and drug survival (rate and duration of adherence to a specific drug regimen) in pediatric patients with moderate to severe psoriasis? Findings In this cohort study including 234 pediatric patients with moderate to severe psoriasis, those receiving biologics were more likely than those treated with methotrexate to achieve a Physician Global Assessment status of clear/almost clear and 75% or more improvement of the Psoriasis Area and Severity Index rating at 6 months. In addition, biologics were associated with better drug survival rates at 1, 3, and 5 years, with comparable discontinuation rates owing to lack of response. Meaning In pediatric patients with psoriasis, treatment with biologics may be associated with a significantly greater reduction in psoriasis severity than methotrexate; nevertheless, with 35.6% of the patients achieving clear/almost clear and 40.0% reaching 75% or more improvement on the Psoriasis Area and Severity Index, methotrexate remains an effective treatment for pediatric psoriasis. Importance Few studies have compared the use of methotrexate and biologics, the most commonly used systemic medications for treatment of moderate to severe psoriasis in children. Objective To assess the real-world, 6-month reduction in psoriasis severity and long-term drug survival (rate and duration of adherence to a specific drug) of methotrexate vs biologics in plaque psoriasis in children. Design, Setting, and Participants A retrospective medical records review was conducted at 20 European and North American centers. Treatment response was based on site-reported Psoriasis Area and Severity Index (PASI) and/or Physician Global Assessment (PGA) scores at baseline and within the first 6 months of treatment. Participants included all 234 consecutively seen children with moderate to severe psoriasis who received at least 3 months of methotrexate or biologics from December 1, 1990, to September 16, 2014, with sufficient data for analysis. Data analysis was performed from December 14, 2015, to September 1, 2016. Main Outcomes and Measures PASI, with a range from 0 to 72 (highest score indicating severe psoriasis), and/or PGA, with a scale of 0 (clear), 1 (minimal), 2 (mild), 3 (moderate), 4 (severe), and 5 (very severe). Results Of 234 pediatric patients (103 boys [44.0%]; 131 girls [56.0%]) treated with methotrexate and/or biologics, 163 patients (69.7%) exclusively received methotrexate, 47 patients (20.1%) exclusively received biologics, and 24 children (10.2%) received methotrexate and biologics sequentially. Of the latter cohort, 23 children were treated initially with methotrexate. Mean (SD) age at initiation was 11.6 (3.7) years for methotrexate and 13.3 (2.9) years for biologics (73.2% for etanercept) (P = .002). Among patients evaluated by a scoring method at 6-month follow-up, 75% or greater improvement in PASI (PASI75) was achieved in 12 of 30 patients (40.0%) receiving methotrexate and 20 of 28 patients (71.4%) receiving biologics, and PGA was clear/almost clear (PGA 0/1) in 41 of 115 patients (35.6%) receiving methotrexate and 18 of 37 patients (48.6%) receiving biologics. Achieving PASI75 and/or PGA 0/1 between baseline and 6 months was more likely with biologics than methotrexate (PASI75: odds ratio [OR], 4.56; 95% CI, 2.02-10.27; P < .001; and PGA 0/1: OR, 2.00; 95% CI, 0.98-4.00; P = .06). Decreased mean PASI and PGA scores were associated with biologics more than with methotrexate (PASI effect, -3.13; 95% CI, -4.33 to -1.94; P < .001; and PGA effect, -0.31; 95% CI, -0.56 to -0.06; P = .02). After 1, 3, and 5 years of use, overall drug survival rates for methotrexate were 77.5%, 50.3%, and 35.9%, and for biologics, the rates were 83.4%, 64.3%, and 57.1%, respectively. Biologics were associated with a better confounder-corrected drug survival than methotrexate (hazard ratio [HR], 2.23; 95% CI, 1.21-4.10; P = .01). Discontinuation owing to lack of response was comparable (HR, 1.64; 95% CI, 0.80-3.36; P = .18). Conclusions and Relevance Methotrexate and biologics appear to be associated with improvement in pediatric psoriasis, although biologics seem to be associated with greater reduction in psoriasis severity scores and higher drug survival rates than methotrexate in the real-world setting. Additional studies directly comparing these medications should be performed for confirmation.