Obesity reduces the drug survival of second line biological drugs following a first TNF-α inhibitor in rheumatoid arthritis patients

Objectives: The aim of this study was to assess whether body mass index (BMI) affects clinical outcomesin rheumatoid arthritis (RA) patients starting a second line biological drug after failure of a first TNF-blocker.Methods: From a longitudinal cohort, we analyzed 292 RA patients (66 obese, 109 overweight, and117 normal-weight) treated with a first ever anti-TNF- drug. Patients discontinuing the therapy werefollowed-up if began a second biological drug. Drug survival, by Kaplan-Meier life analysis, and 12 monthsdisease remission based on the 28-joint Disease Activity Score (DAS28) were assessed for either courseof biologics. The baseline predictors of clinical outcomes were assessed by Cox regression analysis.Results: Survival of the first anti-TNF- drug was lower in obese (39.4%) than in normal-weight (49.1%)patients, but the difference was not statistically significant. Obese patients had the highest hazard todiscontinue the first anti-TNF- drug (HR 1.64, 1.02–2.62 95% IC, P = 0.04), and the lowest percent-age of DAS28-based disease remission at 12 months (P = 0.04). In 97 (37 normal-weight, 36 overweight,24 obese) patients who started a second non-anti-TNF- biological drug, persistence on therapy wassignificantly lower in obese (43.5%) than in normal-weight (80%, P = 0.04) group, and again obesity sig-nificantly predicted drug discontinuation (HR 2.9, 1.08–8.45 95% IC, P = 0.04). Significantly, less obesepatients attained a disease remission (12%, P = 0.004) at 12 months.Conclusion: Our study provides evidence that obese RA patients poorly respond to second line non-anti-TNF- drugs after failure of a first TNF- inhibitor.