Real-world treatment patterns, healthcare resource utilisation and costs in patients with systemic lupus erythematosus treated with belimumab: a retrospective analysis of claims data in the USA.

Objective: To examine the effects of belimumab initiation on healthcare resource utilisation (HCRU) and costs in SLE. Methods: This retrospective observational cohort study used healthcare administrative claims data from the IBM MarketScan Commercial Claims and Encounters Database to identify patients with SLE billing codes who received ≥1 intravenous belimumab infusion between March 2011 and December 2015. The first belimumab administration was the 'index date'. During the 6-month postindex period, nine belimumab infusions were recommended: three during the initiation period and six during the maintenance period. HCRU and cost data for inpatient admissions, emergency department visits, physician office visits, hospital-based outpatient visits, laboratory services, other outpatient services and outpatient pharmacy prescriptions were compared in the 6-month pre/postindex periods. Results: Of the 1879 patients with SLE included, 43% received ≥3 intravenous initiation administrations. An average of 5.3 (SD: 2.4) of the nine recommended belimumab administrations were received within 6 months. In the 6-month preindex versus postindex periods, significant reductions were noted for inpatient hospitalisations (18% vs 9%, p<0.001; mean visits: 0.3 vs 0.14, p<0.001) and emergency department visits (40% vs 24%, p<0.001; mean visits; 3.53 vs 1.96, p<0.001). Mean total costs were higher in the 6-month postindex versus preindex period ($41 426 vs $29 270; p<0.001). Conclusions: In this study of real-world intravenous belimumab for SLE, adherence to recommended infusion schedules was low. Outpatient healthcare and associated costs were higher in the 6 months after belimumab was initiated, although inpatient costs were lower. Reasons for non-adherence with belimumab and implications should be investigated.