Impact of the Sociodemographic Index on Efficacy/Safety of Tofacitinib in Patients with Rheumatoid Arthritis: Post Hoc Analysis of Phase 2/3/3b/4 Studies

INTRODUCTION: We explored the impact of the Sociodemographic Index (SDI) on the efficacy/safety of tofacitinib and adalimumab in patients with rheumatoid arthritis (RA). METHODS: This post hoc analysis used data from phase 2/3/3b/4 studies of patients with RA receiving tofacitinib 5 or 10 mg twice daily (BID), adalimumab 40 mg every 2 weeks, or placebo. Patients were stratified into country-level SDI tertiles (low/medium/high; defined as Global Burden of Disease 2010 scores of ≤ 0.708/> 0.708-≤ 0.803/> 0.803). Efficacy/patient-reported outcomes were evaluated to month (M)3. We calculated incidence rates (IRs) for safety outcomes through M24. Pooled data are reported for tofacitinib 5 and 10 mg BID. RESULTS: Patients: low SDI, N = 1969; medium SDI, N = 1538; high SDI, N = 3071. There was a higher percentage of patients aged ≥ 50 years, ever smokers, and prior biologic disease-modifying antirheumatic drug users, and RA duration was longer, in the high vs low/medium SDI tertiles. Across SDI tertiles, efficacy at M3 was generally greater with tofacitinib or adalimumab vs placebo. Odds ratios vs placebo showed that American College of Rheumatology 20/70 responses at M3 for tofacitinib or adalimumab were numerically greatest (i.e., 95% confidence intervals [CIs] overlapped) in the high SDI tertile. Placebo-adjusted least squares mean change from baseline in Disease Activity Score in 28 joints with C-reactive protein/erythrocyte sedimentation rate and Clinical Disease Activity Index at M3 was greater in the high vs low/medium SDI tertile (95% CIs overlapped) with tofacitinib or adalimumab. For tofacitinib or adalimumab, IRs for adverse events/serious adverse events were numerically greatest in the high SDI tertile. CONCLUSIONS: Efficacy at M3 was at least numerically greater with tofacitinib or adalimumab vs placebo, regardless of SDI. Placebo-adjusted efficacy responses were at least numerically greater in patients from high SDI countries. Safety IRs were also generally numerically greatest in the high SDI tertile with tofacitinib or adalimumab. Results were confounded by differences in demographics/baseline characteristics and associated lifestyle factors between SDI tertiles. TRIAL REGISTRATION: ClinicalTrials.gov: NCT00147498, NCT00413660, NCT00960440, NCT00550446, NCT00603512, NCT00687193, NCT00847613, NCT00814307, NCT00856544, NCT00853385, NCT01164579, NCT01039688, NCT00976599, NCT01359150, and NCT02187055.