INTRODUCTION

Crohn's disease (CD) yields a considerable burden to the Spanish National Health System (NHS). Thanks to the advent of adalimumab and infliximab biosimilars (bADA, bINF), costs burden decreased substantially. However, a further assessment on additional efficiencies is warranted. The NHS’s Willingness to Pay (WTP) per additional Quality Adjusted Life Year (QALY) could be considered an important metric to assess.

OBJECTIVES:

To quantify, with current drug acquisition costs (October 2021):

• QALYs per patient when comparing different sequences in CD treatment, starting with bADA or bINF or other biologics -vedolizumab (VED), ustekinumab (UST), following loss of response to initial conventional therapy (CT) –immunomodulators and/or corticosteroids.
• Net Monetary Benefit per patient (NMB = WTP* ΔQALY - ΔCosts) provided by each of above treatment sequences.

MATERIAL AND

METHODS:

We used a hybrid model, according to the CD clinical practice; made of two subsets: first, a decision tree to accommodate short induction phase; and second, Markov-state transition model to simulate patients within long-term maintenance phase. All including both direct and indirect costs, as well as clinical outcomes.

Model spanned 5 and 10 years’ time horizons. Costs and benefits discounted at annual rate of 3%, whilst 20,000 €/QALY as WTP; deterministic and probabilistic sensitivity analyses were performed.

RESULTS:

Over a 10-year time horizon, sequences commencing with two biosimilars –cycling- remain the most cost-effective choice for the NHS. In particular, bADA followed by bINF provides with additional 0.06 QALYs, and €2,045 NMB versus UST followed by bADA, becoming dominant (less expensive more efficacious) too. Shortening the time horizon to 5 years, results were 0.07 and €6,532 respectively, while maintaining the dominancy.

CONCLUSIONS:

According to the analysis performed, within moderate-to-severe CD treatment, biosimilar cycling (bADA, bINF) provides higher cost-effectiveness and QALYs for both NHS and patients. This merits further research on real world setting