Article Text
Abstract
Objective Long-term extension (LTE) studies of belimumab in SLE do not include a comparator arm, preventing comparisons between belimumab plus standard therapy and standard therapy alone for organ damage accrual. Propensity score matching can be used to match belimumab-treated patients from LTE studies with standard therapy–treated patients from observational cohort studies. This analysis was designed to compare organ damage progression between treatment groups (belimumab plus standard therapy vs standard therapy alone) in patients with SLE with ≥5 years of follow-up, reproducing our previous study with more generalisable data.
Methods This exploratory post hoc analysis used a heterogeneous population of US and non-US patients receiving monthly intravenous belimumab from pooled BLISS LTE trials (BEL112234/NCT00712933) and standard therapy–treated patients from the Toronto Lupus Cohort. Sixteen clinical variables were selected to calculate the propensity score.
Results The 592 LTE and 381 Toronto Lupus Cohort patients were highly dissimilar across the 16 variables; an adequately balanced sample of 181 LTE and 181 matched Toronto Lupus Cohort patients (mean bias=3.7%) was created using propensity score matching. Belimumab treatment was associated with a smaller increase in Systemic Lupus International Collaborating Clinics/American College of Rheumatology Damage Index (SDI) over 5 years than standard therapy alone (mean treatment difference=–0.453 (95% CI –0.646 to –0.260); p<0.001). Patients treated with belimumab were 60% less likely to progress to a higher SDI score over any given year of follow-up, compared with standard therapy alone (HR (95% CI) 0.397 (0.275 to 0.572); p<0.001).
Conclusion Using propensity score matching, this highly heterogeneous sample was sufficiently matched to the Toronto Lupus Cohort, suggesting that patients treated with intravenous belimumab may have reduced organ damage progression versus standard therapy alone. This analysis of a large and diverse pooled SLE population was consistent with our previously published US-focused study.
- autoimmune diseases
- lupus erythematosus
- systemic
- therapeutics
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Footnotes
Contributors MBU, RLO, RCW, JJD, MZ, YA, SR and AVJ were involved in the concept or design of the study and the analysis of the data. MBU, YA, SR and AVJ were involved in the acquisition of data. MBU, RLO, RCW, JJD, MZ, YA, SR and AVJ approved the final manuscript.
Funding This study was funded by GlaxoSmithKline (GSK 206347).
Competing interests MBU has received research grants from GSK. YA, SR and AVJ are employees of GSK and hold stocks and shares in GSK; RCW, JJD and MZ are employees at Medical Decision Modeling Inc., contracted by GSK for this analysis. RLO is a non-employee consultant for Medical Decision Modeling Inc.
Patient and public involvement Patients and/or the public were not involved in the design, or conduct, or reporting, or dissemination plans of this research.
Patient consent for publication Not required.
Ethics approval The original parent studies (BEL110751 and BEL110752) and the BLISS LTE studies (BEL112233 and BEL112234) were conducted in accordance with the ethical principles of the Declaration of Helsinki, the International Council for Harmonisation on Good Clinical Practice, and the applicable country-specific regulatory requirements.
Provenance and peer review Not commissioned; externally peer reviewed.
Data availability statement GSK makes available anonymised individual participant data and associated documents from interventional clinical studies which evaluate medicines, upon approval of proposals submitted to www.clinicalstudydatarequest.com. To access data for other types of GSK sponsored research, for study documents without patient-level data and for clinical studies not listed, please submit an enquiry via the website.