INTRODUCTION

Rheumatoid arthritis (RA) is a highly debilitating chronic disease posing significant financial burden to the National Healthcare System (NHS).

Whilst options to treat RA patients like conventional synthetic, biologic, or targeted synthetic disease-modifying anti-rheumatic drugs (csDMARDs, bDMARDs, tsDMARDs) exist; anti-tumour necrosis factor’s biosimilars -(anti-TNFb)_ adalimumab (bADA), etanercept (bETN), infliximab (bINF)- have arguably changed the landscape by bringing significant cost reductions and probably early access to biological therapy.

OBJECTIVES:

To assess incremental cost-effectiveness ratio (ICER) of moderate-to-severe RA patients from Spanish NHS perspective considering different treatment sequences made of anti-TNFb, other bDMARDs, and tsDMARDs -compared to csDMARDs-, following an initial loss of response to the latter.

Additionally, to calculate Net Monetary Benefit per patient (NMB = ∆QALY * WTP - ∆Costs) assuming an NHS Willingness to Pay (WTP) threshold of €20,000 per QALY (Quality Adjusted Life Year) gained.

MATERIAL AND

METHODS:

A cost-effectiveness model considering a cohort-based Markov model simulating RA patients in Spain over 5- and 10-year time horizon was built. We sourced relevant treatment comparisons following a Systematic Literature Review. Actual drug acquisition costs were synthetized from a specialized database on public tenders and discounted, along with QALYs at 3% yearly rate.

We performed Deterministic and Probabilistic Sensitivity Analyses, including 95% confidence intervals (95%CI).

RESULTS:

Compared to csDMARDs, treatment sequences made of initial bADA were dominant;, with bADA followed by bETN turning out the most cost-effective alternative: ranging from 5 years NMB= €6,022 (95%CI: €5,888 - €6,781) to 10 years’ €10,256 (95%CI: €9,438 - €11,001).

Sequencing in any order biosimilars and tsDMARDs, led to more costly but more effective outcomes; 5 years NMB from bADA followed by upadacitinib yielded €2,255 (95%CI: €1,987 - €2,604); whilst UPA then bADA €1,460 (95%CI: €1,187 - €1,781).

CONCLUSIONS:

In moderate-to-severe RA, early biosimilar treatment is the most cost-effective choice for the NHS in Spain.