Cost-Effectiveness of Biosimilars vs Leflunomide in Patients With Rheumatoid Arthritis

Area of Science:

• Rheumatology
• Health Economics
• Pharmacoeconomics

Background:

• Methotrexate is a common initial treatment for rheumatoid arthritis (RA).
• Patients with inadequate response to methotrexate require alternative therapies.
• Current guidelines recommend conventional synthetic DMARDs, but biosimilar efficacy and cost-effectiveness are key considerations.

Purpose of the Study:

• To evaluate the cost-effectiveness of initiating treatment with biosimilar DMARDs versus leflunomide after methotrexate failure in RA patients.
• To provide evidence for formulary listing decisions regarding RA treatment sequences.

Main Methods:

• Economic evaluation using a Markov disease transition model simulating lifetime RA progression.
• Comparison of three treatment sequences: biosimilar infliximab, biosimilar adalimumab, and leflunomide, all combined with methotrexate.
• Analysis of lifetime healthcare costs and quality-adjusted life-years (QALYs) based on retrospective data from 25,099 RA patients.

Main Results:

• Biosimilar sequences (infliximab and adalimumab) demonstrated lower lifetime costs and higher QALYs compared to leflunomide.
• Probabilistic sensitivity analysis showed biosimilar adalimumab had a 91% probability of being cost-effective, while biosimilar infliximab had a 9% probability.
• Incremental cost-effectiveness ratios were below the willingness-to-pay threshold, indicating favorable cost-effectiveness for biosimilar sequences.

Conclusions:

• Treatment sequences initiated with biosimilar DMARDs are cost-effective compared to leflunomide for RA patients who failed methotrexate.
• The findings suggest a need to update clinical guidelines to recommend initiating biosimilars sooner after methotrexate failure.
• This economic evidence supports the inclusion of biosimilars in RA treatment protocols to improve both clinical outcomes and cost-effectiveness.