Impact of baseline body mass index on the efficacy and safety of tofacitinib in patients with psoriatic arthritis

OBJECTIVES: This post-hoc analysis explored the impact of body mass index (BMI) on tofacitinib efficacy/safety in patients with active psoriatic arthritis (PsA). METHODS: Data were pooled from two phase 3 studies (NCT01877668; NCT01882439). Analyses included patients randomised to tofacitinib 5/10 mg two times a day or placebo, stratified by baseline BMI: <25 kg/m(2), ≥25–<30 kg/m(2), ≥30–<35 kg/m(2) or ≥35 kg/m(2). Endpoints (month 3): American College of Rheumatology (ACR20/50/70), Health Assessment Questionnaire-Disability Index (HAQ-DI) and Psoriasis Area and Severity Index (PASI) 75 response rates; dactylitis/enthesitis resolution rates; changes from baseline Short Form-36 Health Survey version 2 (SF-36v2) Physical/Mental Component Summary (PCS/MCS) scores and Functional Assessment of Chronic Illness Therapy-Fatigue (FACIT-F) total score. Safety was also reported. RESULTS: Analysis included 710 patients; 43.8% were obese (BMI ≥30 kg/m(2)). Tofacitinib demonstrated higher efficacy response rates at month 3, compared with placebo, regardless of baseline BMI. Generally, ACR20/50/70 and HAQ-DI response rates, enthesitis resolution rates and changes from baseline in SF-36v2 PCS score and FACIT-F total score (month 3) were reduced in patients with baseline BMI ≥35 kg/m(2) versus patients with lower BMIs. Elevated alanine aminotransferase/aspartate aminotransferase levels were reported in patients with baseline BMI ≥35 kg/m(2) receiving tofacitinib 5 mg but not 10 mg two times a day. CONCLUSION: Tofacitinib demonstrated greater efficacy than placebo in patients with PsA, regardless of baseline BMI. For all treatment arms, reduced efficacy was observed in patients with baseline BMI ≥35 kg/m(2). Safety was generally comparable across BMI categories, although the effect of tofacitinib on liver enzymes in patients with baseline BMI ≥35 kg/m(2) was inconclusive.