Phase 3 Study Underway for Proposed Etanercept Biosimilar, SCB-808

China-based Clover Biopharmaceuticals announced this week that it has dosed the first patient in a phase 3 clinical study of SCB-808, a proposed etanercept biosimilar referencing Enbrel.

The study, taking place at multiple centers in China, is being conducted in patients with ankylosing spondylitis, and it uses a prefilled syringe formulation of the biosimilar.

“The treatment of ankylosing spondylitis and other rheumatic diseases remains a high unmet medical need in China, as the majority of patients remain severely undertreated. Currently, the lack of affordable, convenient and high-quality biologics therapies presents a major hurdle to wide patient adoption and compliance,” said Dr Feng Huang, leading principal investigator, in a statement. “My team and I look forward to evaluating SCB-808 as a potential new and convenient therapeutic option for the treatment of patients with rheumatic diseases in China.”

The development of SCB-808 is notable because currently available follow-on etanercept products in China were approved prior to the establishment of a biosimilar approval pathway. As such, they were not routinely compared to the reference product in clinical trials as a means to demonstrate bioequivalence.

Additionally, the available follow-ons are also only available in powder formulations, all of which must be reconstituted by medical professionals before injection. Clover says that its product could help address the unmet need for a ready-for-injection biosimilar that patients can use at home.

China’s biosimilar market is relatively nascent, with the first biosimilar—a rituximab biosimilar referencing Rituxan and developed by Henlius—having been approved in early 2019. China’s regulatory agency forged its national guidelines for developing and evaluating biosimilars in 2015, and used principles and requirements consistent with those used by the FDA and the European Medicines Agency.

Since that time, development of new biosimilars has in China, with companies such as Bio-Thera Solutions and Eli Lilly and Company working on biosimilar products for the market. Additionally, established biosimilar players from around the globe have sought entry into China, with companies including Republic of Korea-based Celltrion having formed local agreements that will allow market entry for eventually approved products.