Clover Biopharma of Chengdu has tested the first subjects in a Phase I first-in-human study testing the company's COVID-19 S-Trimer subunit vaccine candidate (SCB-2019). The vaccine is based on Clover’s proprietary Trimer-Tag© vaccine technology platform. The company expects to release preliminary safety and immunogenicity results for the Phase I study in August 2020, and it has already begun planning for a global Phase IIb/III efficacy trial projected to start by year-end 2020.

The Phase I study will evaluate SCB-2019 along with two adjuvants– GSK’s (NYSE: GSK) pandemic adjuvant system and Dynavax’s (NSDQ: DVAX) CpG 1018 adjuvant combined with alum. Because an adjuvant reduces the amount of antigen needed per dose, they are crucial in pandemic outbreaks.

Clover's Trimer-Tag© platform allows the production of novel, covalently-trimerized fusion proteins. Like other enveloped RNA viruses such as HIV, RSV and Influenza, SARS-CoV-2 is an RNA virus that has a trimeric spike (S) protein on its viral envelope. The trimeric S protein of SARS-CoV-2 is responsible for binding to host cell surface receptor ACE2 and subsequent viral entry, making it the primary target antigen for vaccine development.

Preclinical tests showed the ability of adjuvanted SCB-2019 to create neutralizing antibodies in multiple animal species. Because of this, Clover has expanded its collaborations with GSK and Dynavax to include clinical supply of the adjuvants.

The Phase I clinical trial is a randomized, double-blind, placebo-controlled study to assess the safety, reactogenicity and immunogenicity of SCB-2019 at multiple dose levels. Each SCB-2019 dose level will be evaluated with and without adjuvant. The study is being conducted in Perth, Australia and will enroll approximately 90 healthy adult participants and 60 healthy elderly participants.

The trial and Clover’s COVID-19 vaccine program is being supported by the funding and collaboration with the Coalition for Epidemic Preparedness Innovations (CEPI).

Joshua Liang, CEO of Clover and co-inventor of COVID-19 S-Trimer vaccine candidate said: “We are pleased to achieve this significant milestone for our COVID-19 vaccine candidate, as the entire Clover team and our collaborators around the world have been working nonstop since late-January on this important program for the world. More than ever, Clover remains focused on developing a safe, effective and accessible COVID-19 vaccine at a scale that could potentially impact the course of the pandemic globally.”

Dr. Peng Liang, Founder and Chairman of Clover and inventor of Trimer-Tag© technology added: “Dosing the first participants in this Phase I study brings us one step closer to developing a safe and effective vaccine for COVID-19 and our clear objective of producing and supplying our COVID-19 vaccine to the world. As a China headquartered company, Clover is proud to achieve this important milestone which is the result of global collaboration across several continents against a common enemy – COVID-19.”

In early 2020, after the genomic DNA sequence of the SARS-CoV-2 virus was disclosed, Clover scientists started designing the viral spike (S)-protein construct and completed its gene synthesis. Using its patented Trimer-Tag© technology, Clover produced a COVID-19 S-Trimer subunit vaccine candidate that resembles the native trimeric viral spike via a rapid mammalian cell-culture based expression system.

With one of the largest in-house, commercial-scale cGMP biomanufacturing capabilities in China, Clover believes it can rapidly scale-up and produce large-quantities of a new coronavirus vaccine.

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Disclosure: none.