Budget impact of introducing tofacitinib to the public hospital formulary in Hong Kong, 2017-2021

Abstract

As the first approved oral kinase inhibitor, tofacitinib is effective and well-tolerated, but more expensive than conventional treatments for uncontrolled rheumatoid arthritis. Public formulary listing typically exerts a positive impact on the uptake of new drugs. We aimed to assess the budgetary impact of introducing tofacitinib into the Hospital Authority Drug Formulary as a fully subsidised drug in Hong Kong. Methods: We applied a population-based budget impact model to trace the number of eligible patients receiving biologics or tofacitinib treatment, then estimated the 5-year healthcare expenditure on rheumatoid arthritis treatments, with or without tofacitinib (2017-2021). We used linear regression to estimate the number of target patients and compound annual growth rate to estimate market share. Competing treatments included abatacept, adalimumab, certolizumab pegol, etanercept, golimumab, infliximab, and tofacitinib. Retail price was used for drug costs, valued in Hong Kong dollars