Demand- Versus Supply-Side Policies in Market Penetration of Biosimilars: Which is More Effective?

Objective: To evaluate the impact of demand- and supply-side policies on the biosimilar market penetration and identify effective strategies for promoting biosimilar uptake in eight high-income countries.

Methods: We analyzed biosimilar market penetration for infliximab, rituximab, and trastuzumab in six European countries-France, Germany, Italy, Spain, Sweden, and the UK-and two Asian countries-Japan and South Korea. Biosimilar market penetration was measured using two indicators: biosimilar market share and the time required for biosimilars to reach the majority point (> 50% market share). Policies were categorized into demand- and supply-side measures, and weights were applied to reflect the extent and timing of policy implementation. Spearman correlation examined the relationship between policy implementation and biosimilar market penetration.

Results: Sweden, Italy, and the UK showed the highest biosimilar market shares, adopting various demand-side policies, while Japan and South Korea exhibited slower biosimilar adoption with fewer or no demand-side policies. Biosimilars in most European countries reached the majority point within 5-6 quarters, while projections for Japan and South Korea exceeded 30 quarters. Correlation analysis revealed that adoption of demand-side policies was significantly associated with higher market share (r_s = 0.69, p < 0.001) and shorter time to reach the majority point (r_s = - 0.62, p < 0.01). In contrast, supply-side policies showed a weaker and less consistent association.

Conclusions: Demand-side policies, such as financial incentives and prescribing guidelines, are significantly associated with rapid and widespread biosimilar adoption, while supply-side policies had limited impact. Policymakers should prioritize demand-side measures to improve biosimilar uptake and reduce healthcare expenditures effectively.