Background and Objective
Regulatory approval of biosimilars often depends on extrapolating evidence from one clinical indication to all of those of the originator biologic. We aimed to develop a quantitative benefit-risk analysis to assess whether the resulting increase in the uncertainty in the clinical performance of biosimilars (i.e. risk) may be countered by their lower pricing (benefit).
A 1-year decision-analytic model was developed for the biosimilar infliximab (Inflectra®) for Crohn’s disease. The perspective was that of the National Health Service in the UK and costs were valued to 2015/16. A hypothetical cohort of biologic-naïve patients with moderate-to-severe Crohn’s disease was simulated through the model. Immunogenicity to infliximab was a key modifier, influencing rates of non-response and infusion reactions. Net health benefit was estimated based on quality-adjusted life-years. A range of sensitivity analyses tested the robustness of the results and explored how the biosimilar price must respond to varying immunogenicity to remain the preferred option.
The base-case analysis predicted a positive incremental net health benefit of 0.04 (95% central range 0.00–0.09) favouring the biosimilar, based on 0.803 quality-adjusted life-years, and costs of £18,087 and £19,176 for the biosimilar and originator, respectively. Two-way sensitivity analyses suggested that if 50% of patients developed antibodies, the value-based price of £410 per vial must be lower than that of the originator (£420), but remain higher than the actual market price (£378).
The model supports the use of Inflecta® for Crohn’s disease in the UK, and provides a framework for the quantitative evaluation of biosimilars in the context of a health technology assessment. Value-based pricing using this methodology could protect health systems from the potential risks of biosimilars where they are untested in the approved populations.