OBJECTIVES : The C-OPTIMISE trial (NCT02505542) demonstrated that reduced certolizumab pegol (CZP) maintenance dose (RMD, 200mg every 4 weeks [Q4W]) is a possible regimen for adults with axial spondyloarthritis (axSpA) in sustained remission. This analysis explored the budget impact of introducing CZP RMD for axSpA in the UK.

METHODS : The eligible population of UK axSpA patients (prevalence 0.13%) treated with tumour necrosis factor (TNF) inhibitors (17.3%, Wilmington database 2019) was estimated and updated quarterly over five years (2020–2024). Drug acquisition (including branded and biosimilar products), administration and direct medical management costs (GBP, 2020) were applied to the estimated market share for each treatment. No discounting was applied. A reference scenario considering CZP full maintenance dose (FMD; 200mg Q2W) with 0.5% CZP annual market share growth was compared to a scenario where the RMD was applied to 44% of CZP patients assumed to have achieved sustained remission after one year. A marginally higher risk of disease flare on RMD (21%) compared to FMD (16%) was accounted for. An annual all-cause discontinuation rate of 10% was applied to all treatments.

RESULTS : Assuming a market share of 10% for CZP at baseline (1,177 patients), CZP RMD in eligible patients generated a £13.34 million saving in CZP drug costs between 2021 and 2024 (-19.95% vs. CZP FMD). Incremental flare costs were marginal (£6,074; +0.11% vs. FMD). Overall, net savings with RMD were £13.33 million, out of £627.17 million total spend in the FMD scenario. Scenario analysis of RMD suggested that cost savings were still realised within reasonable CZP market share uptake assumptions.

CONCLUSIONS : CZP RMD for axSpA patients in sustained remission led to net savings compared to continuing FMD regimen in the UK, due to lower overall cost of treatment despite a marginal direct cost increase associated with marginally higher risk of disease flare.