CHENGDU, China – 10 February 2020 – Clover Biopharmaceuticals, a global clinical-stage biotechnology company focused on developing novel and transformative biologic therapies, announced today that it has successfully produced its trimeric Spike-protein (“S-Trimer”) subunit vaccine candidate for 2019-nCoV via a mammalian cell expression system. In addition, Clover scientists have used the newly obtained S-Trimer and successfully detected antigen-specific antibody in sera from multiple fully recovered patients who were previously infected by the virus. Importantly, Clover is the first company in the world to disclose a 2019-nCoV vaccine candidate that can successfully be recognized by antibodies produced by previously-infected patients, supporting that S-Trimer has preserved the native structure of the viral spike (S) protein and thus may elicit a protective-immune response as a vaccine. This work was carried out with the support of leadership teams from Chengdu Hi-Tech Park and Chengdu Clinical Center for Public Health in China.

Similar to other enveloped RNA viruses such as HIV, RSV and Influenza, 2019-nCoV is also an RNA virus that has a trimeric spike (S) protein on its viral envelope. The trimeric S protein of 2019-nCoV is responsible for binding to host cell surface receptor ACE2 and subsequent viral entry. Symptoms in infected patients include fever, coughing and breathing difficulties, and it can be fatal.

Upon knowing the genomic DNA sequence of this newly identified 2019-nCoV last month, Clover scientists immediately started designing the viral S-protein construct and completed its gene synthesis. Utilizing our patented Trimer-Tag© technology, Clover has produced a S-Trimer subunit vaccine that resembles the native trimeric viral spike via a rapid mammalian cell-culture based expression system. Having one of the largest in-house, commercial-scale cGMP biomanufacturing capabilities in China, Clover could potentially be able to rapidly scale-up and produce large-quantities of a new coronavirus vaccine.

Clover has previously developed recombinant subunit-Trimer vaccines for RSV and Influenza viruses utilizing its Trimer-Tag© technology and has demonstrated that they are able to evoke protective neutralizing antibody responses in multiple animal models.

“I am very excited that Clover has achieved high-level expression of the native-like trimeric viral Spike protein (S-Trimer) in mammalian cells in record time, and importantly, we have used the newly-obtained vaccine candidate to successfully detect viral S protein-specific antibodies from the sera of multiple patients who recently recovered from 2019-nCoV infection in China. The implication of this discovery is that it not only has validated the correct conformation of our S-Trimer subunit vaccine candidate, but also further supports that the new 2019-nCov virus is indeed the culprit for the current epidemic, since all previous diagnosis for the viral infections have been based on nucleic acid detection. This important finding forms a solid foundation for the continued rapid development of S-Trimer vaccine through pilot production, preclinical efficacy and safety studies, followed by human clinical trials and subsequent large-scale production.” said Dr. Peng Liang, co-founder, Chairman and President of Clover. “We remain confident that Clover can be among one of the first companies to develop a successful vaccine to contain the 2019-nCoV epidemic, as well as any future outbreaks of similar coronaviruses”.

“We are encouraged by the rapid progress of our S-Trimer vaccine development for 2019-nCoV and hope to support global efforts in fighting this epidemic,” said Joshua Liang, Chief Strategy Officer and Board Director at Clover. “To this end, we recognize that collaborations will be critical to accelerating the development of a successful new vaccine in times of emergency, and we invite any interested regulatory, academic or industry parties to contact us for this noble common cause.”

About Clover Biopharmaceuticals
Clover Biopharmaceuticals is a global, clinical-stage, research-based biotechnology company focused on discovering, developing and commercializing transformative biologic therapies, with a focus on oncology and autoimmune diseases, as well as viral vaccines. Having raised more than US$ 100 million in total capital since 2016, 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. For more information, please visit our website:

About Trimer-Tag© Technology
Trimer-Tag© is an innovative drug development platform which allows the production of novel, covalently-trimerized fusion proteins. Many major disease targets are trimerization-dependent such as the tumor necrosis factor superfamily (involved in extrinsic apoptosis, immune co-stimulation and inflammation) as well as enveloped RNA virus antigens responsible for entry into host cells. Clover is using Trimer-Tag technology to create trimerized fusion proteins that are able to effectively target these previously undruggable pathways.

About GSK
GSK is a science-led global healthcare company with a special purpose: to help people do more, feel better, live longer. GSK is the leading manufacturer of vaccines globally. For further information please visit

Clover Biopharmaceuticals
Joshua Liang, +86 028-63925705