Impact of Body Mass Index on the Efficacy of Biological Therapies in Patients with Psoriasis: A Real-World Study

Background The efficacy of biological therapies used for the treatment of chronic plaque psoriasis can be influenced by numerous variables including body mass index (BMI). Objective This study aimed to evaluate the impact of BMI on the short-term and long-term efficacy of biological therapies in clinical practice and to identify the best therapeutic options in obese patients (BMI >= 30 kg/m(2)). Methods A multicentric retrospective study was conducted in patients who initiated a biological therapy during the period January 2006-December 2019. The proportion of patients achieving a 90% improvement of baseline Psoriasis Area and Severity Index at weeks 12 and 24 was calculated also recording the 12- and 24-month drug survival as a measure of long-term efficacy, performing multivariate analyses to assess the impact of different variables. Results Five hundred and four patients with psoriasis were included. After 12 and 24 weeks, the proportion of patients achieving a 90% improvement of baseline Psoriasis Area and Severity Index response was higher in patients with a BMI < 30 kg/m(2) compared with those with a BMI >= 30 kg/m(2) [54.90% vs 43.45% (p = 0.014) at week 12 and 66.84% vs 56.55% (p = 0.021) at week 24]. The Kaplan-Meier survival curves showed how obese patients had a higher probability of discontinuation due to a lack or loss of efficacy (p = 0.0192) compared with non-obese patients. The drug survival analysis also showed that BMI negatively affected the drug survival of secukinumab (odds ratio 1.27, p < 0.001) and ustekinumab (odds ratio 1.06, p = 0.050), while the long-term efficacy of adalimumab, etanercept, and ixekizumab was not influenced by BMI. Conclusions Obesity (BMI >= 30 kg/m(2)) negatively affects the clinical response of biological drugs in psoriatic patients, with anti-interleukin drugs being more affected by BMI than anti-tumor necrosis factor drugs.