Samsung Bioepis' Epysqli, a biosimilar to eculizumab targeting complement C5, has been approved by the U.S. Food and Drug Administration (FDA). This approval is significant not only as a biosimilar but also because it has achieved interchangeable status, allowing for substitution at the pharmacy level for the original drug, Soliris. This has a substantial impact on the market. Samsung Bioepis, a leading global biosimilar company, has partnered with Teva, a global pharmaceutical company with a strong local distribution network, to commercialize Epysqli in the U.S., marking a significant shift in the U.S. complement inhibitor market.

The key basis for this FDA approval is the results of a large, global Phase 3 clinical trial conducted on patients with paroxysmal nocturnal hemoglobinuria (PNH). The clinical team measured lactate dehydrogenase (LDH) levels, a key indicator of intravascular hemolysis, at week 26, demonstrating clear therapeutic equivalence to the original drug. Furthermore, the Epysqli group showed a transfusion avoidance rate of 68.1%, compared to 72.9% for the Soliris group, with no statistically significant difference (p=0.4492), confirming the drug's safety and complete immunogenicity equivalence.

A commercial partnership between Samsung Bioepis, responsible for development and supply, and Teva, responsible for sales with its global distribution network, was established in January 2025. The companies plan to launch Epysqli at a wholesale acquisition cost (WAC) that is approximately 30% lower than the original product, aiming to alleviate the burden on patients and insurance finances. This price competitiveness is expected to be a significant advantage in the complex U.S. private and public insurance pricing negotiations and, combined with Teva's strong marketing capabilities in the U.S., is expected to accelerate the rate of prescription switching.

The original drug, Soliris, had global sales of approximately $3.145 billion in 2023 and has dominated the complement C5 inhibitor market. However, with the expiration of its patent and the entry of Epysqli with interchangeable status, the market share of Soliris is expected to decline rapidly as Epysqli can be substituted at the pharmacy level without a separate prescription change. Although the original developer, Alexion, is trying to switch patients to its next-generation drug, Ultomiris, the launch of Epysqli, with its attractive price, will undoubtedly be a decisive factor in diversifying the overall C5 complement inhibitor market.