Clover Biopharmaceuticals

Clover Biopharmaceuticals is a global, clinical-stage, research-based biotechnology company focused on discovering, developing and commercializing biologic therapies, with a focus on oncology and autoimmune diseases. Clover is utilizing its proprietary Trimer-Tag technology platform to develop novel biologics targeting trimerization-dependent pathways. Additionally, Clover is leveraging its in-house cGMP biomanufacturing capabilities to develop select biosimilars. Trimer-Tag allows the production of covalently trimerized fusion proteins to target trimerization-dependent pathways such as the tumor necrosis factor (TNF) superfamily and the enveloped RNA virus proteins that allow the virus to gain entry into host cells.

Clover Biopharmaceuticals generated a trimeric Spike-protein (S-Trimer) subunit vaccine candidate for the new coronavirus causing the COVID-19 outbreak. Like other coronaviruses, the COVID-19 coronavirus strain has a trimeric spike (S) protein on the viral envelope that enables the virus to attach to the host cells surface receptor ACE2 and gain entry into the cell. A mammalian cell expression system was used to produce the trimeric Spike-protein. It is an antigen recognized by antibodies in the sera of patients fully recovered from the new coronavirus, which suggests that as a vaccine the Spike-protein trimer could serve as a vaccine by triggering a protective immune response. The vaccine development included partnership with Chengdu Hi-Tech Park and Chengdu Center for Public Health teams. Clover has partnered with GlaxoSmithKline (GSK) in further development of their Covid-19 S-Trimer vaccine candidate. GSK will supply its pandemic adjuvant system for preclinical studies. An adjuvant can reduce the amount of vaccine protein required.