Efficacy of Adalimumab Compared With Methotrexate or Placebo Stratified by Baseline BMI in a Randomized Placebo-Controlled Trial in Patients With Psoriasis

Abstract

Introduction: In the Comparative Study of Humira vs Methotrexate vs Placebo In Psoriasis Patients (CHAMPION) study, significantly more patients achieved ≥75% improvement in the Psoriasis Area and Severity Index (PASI75) and ≥90% improvement (PASI90) after 16 weeks of treatment with adalimumab (80 mg at week 0, then 40 mg every other week starting at week 1) compared with methotrexate (up to 25 mg/week orally) or placebo. In this exploratory analysis, the efficacy of adalimumab was evaluated in a subset of the CHAMPION patient population stratified by baseline body mass index (BMI).

Methods: PASI responses and Dermatology Life Quality Index (DLQI) scores through 16 weeks of treatment were examined by baseline BMI category (<25 kg/m2 [normal], 25 to <30 kg/m2 [overweight], and ≥30 kg/m2 [obese]) in patients with psoriasis with a baseline PASI total score ≥12. Treatment differences between the adalimumab and the methotrexate or placebo groups were compared using Fisher's exact test for PASI responses and 1-way analysis of variance for DLQI scores.

Results: In all BMI categories, adalimumab treatment led to significantly greater rates of PASI75/90 responses at weeks 12 and 16 compared with methotrexate or placebo (P<0.05 for all). In normal weight, overweight, and obese patients at week 16, the respective PASI75 response rates were 85.0%, 85.7%, and 61.3% with adalimumab; 43.3%, 29.3%, and 26.1% with methotrexate; and 28.6%, 16.7%, and 0% with placebo. PASI90 response rates were 70.0%, 53.6%, and 35.5% with adalimumab; 26.7%, 7.3%, and 8.7% with methotrexate; and 9.5%, 16.7%, and 0% with placebo. Across all BMI subgroups, the greatest decreases in DLQI scores from baseline occurred in the adalimumab group.

Conclusion: Significantly higher PASI75/90 response rates and more pronounced improvements in DLQI scores at week 16 were identified in patients treated with adalimumab, compared with methotrexate or placebo, regardless of baseline BMI category.