OBJECTIVES

: As the first approved oral kinase inhibitors for the treatment of rheumatoid arthritis (RA), tofacitinib is an effective, well-tolerated and cost-effective alternative to conventional RA treatments. This research aims to assess the budget impact of introducing tofacitinib to the public hospital formulary as a fully subsidised drug in Hong Kong (HK).

METHODS

: We applied a previously developed population-based budget impact model to track the number of patients eligible to be treated with biologics or tofacitinib. Five-year (2017-2021) healthcare expenditure with or without the introduction of tofacitinib was assessed. Biologic treatment mixes considered abatacept, adalimumab, certolizumab pegol, etanercept, golimumab, infliximab and tocilizumab. Based on the number of patients in all public hospitals in HK, from 2009-2015, we used linear regression to project the number of target patients, and exponential regression to project the market shares of the treatment mixes over five years. Retail price was used for drug costing. Costs were presented in the value of HK Dollars in 2017 and discounted at 4% per year. Scenario analyses were conducted to assess the impact of uncertainties in uptake and dropout.

RESULTS

: The annual per patient treatment cost of tofacitinib is HK$74,214 and the costs for biologics range from HK$64,350-115,700. Without the introduction of tofacitinib, annual governmental health expenditure on the treatment of RA was HK$147.9-190.6 million during 2017-2021. Introducing tofacitinib to the formulary would reduce healthcare expenditure by 17.3-20.3% each year. Cumulative budget savings in five years would be HK$192.8 million. The introduction consistently saved the public healthcare expenditure in all the analytical scenarios (uptake 33.3-100% and yearly dropout 0-20% of tofacitinib) with budget savings ranging from HK$66.4-196.8 million.

CONCLUSIONS

: Introducing tofacitinib to the formulary, for the treatment of patients with RA in HK, is budget saving in five years given the current drug price.