Authors: Thomas Otten, Rob Riemsma, Ben Wijnen, Nigel Armstrong, Lisa Stirk, Caroline Gordon, Bram Ramaekers, Jos Kleijnen, Manuela Joore & Sabine Grimm
As part of its Single Technology Appraisal (STA) process, the National Institute for Health and Care Excellence (NICE) invited the manufacturer (GlaxoSmithKline [GSK]) of Benlysta (belimumab) to submit evidence regarding its clinical and cost effectiveness, for the review and possible extension of a previously conditionally approved intravenous formulation of belimumab for the treatment of active autoantibody-positive systemic lupus erythematosus (SLE). Kleijnen Systematic Reviews Ltd, in collaboration with Maastricht University Medical Centre+, was commissioned to act as the independent Evidence Review Group (ERG). This paper summarises the company submission (CS), presents the ERG’s critical review of the clinical and cost-effectiveness evidence in the CS, highlights the key methodological considerations, and describes the development of the NICE guidance by the NICE Appraisal Committee.
This appraisal is different to the previous appraisal in three ways: (1). This appraisal expands its definition of ‘high disease activity’. (2). In TA397, belimumab was approved, with a managed access arrangement (MAA), for adults only. This appraisal includes subjects aged 5 years or older. (3). The original appraisal included an intravenous formulation only, but the current appraisal also includes a new subcutaneous formulation in the form of a prefilled pen.
The company was required to collect real-world data from the British Isles Lupus Assessment Group Biologics Register (BILAG-BR), including data on the efficacy, safety, and effect on health-related quality of life of belimumab versus rituximab. This appraisal considers these data as well as additional clinical trial evidence presented in the company’s updated submission to address uncertainties identified during the original appraisal. The ERG identified three major concerns with the evidence presented on the clinical effectiveness in the current submission; namely, short follow-up in the main comparative trials (BLISS-SC, BLISS-52 and BLISS-76); using the propensity score-matching (PSM) analysis in calibrating the cost-effectiveness model can severely bias the results in favour of belimumab; and BILAG-BR data are not suitable for a comparison of belimumab with rituximab.
The main issue in the economic analysis was the uncertainty about long-term disease activity progression and resulting organ damage. The company’s approach of calibrating modelled organ damage to longer-term data analysed using the PSM analysis was methodologically inappropriate. The final analysis comparing belimumab with standard treatment for the intravenous formulation resulted in an incremental cost-effectiveness ratio of £12,335 per quality-adjusted life-year (QALY) gained and £30,278 per QALY gained in the company’s and ERG’s base-case analyses, respectively. For the subcutaneous formulation, the final analysis resulted in £8480 per QALY gained and £29,313 per QALY gained in the company’s and ERG’s base-case analyses, respectively. NICE recommended belimumab in both intravenous and subcutaneous formulations as an add-on treatment option for active autoantibody-positive SLE in the HDA-2 subgroup.
Key Points for Decision Makers
The comparison with rituximab was made difficult because data collected to make a comparison between belimumab and rituximab were unsuitable for this comparison. Furthermore, the National Health Service (NHS) England recommended that patients be prescribed belimumab prior to rituximab, which made it an inappropriate comparator.
The incremental cost-effectiveness ratio (ICER) of belimumab compared with standard treatment ranged between £8480 and £68,909 with different model assumptions.
The largest uncertainty in this population was in the long-term comparative effectiveness and, indeed, disease activity progression and resulting accumulation of organ damage. Further data on this should be collected.