Recbio Announces Promising Preliminary Results From First-in-Human Study of a COVID-19 Vaccine Candidate With Novel Adjuvant BFA03

Jiangsu Recbio Technology Co., Ltd. ("Recbio"), a biopharmaceutical company focusing on the research, development and commercialization of innovative vaccines that can address prevalent diseases with significant burden, today announced positive preliminary results from first-in-human(FIH) trial of ReCOV, a new-generation, recombinant two-component COVID-19 subunit vaccine. Overall, the preliminary data demonstrated that ReCOV were well tolerated and showed good safety profile. 20μg ReCOV induced high titer of anti-SARS-CoV-2 neutralizing antibodies, with at least comparable level than published data with mRNA vaccines, predicting a promising potential of ReCOV in preventing SARS-COV-2 induced diseases.

"We are encouraged by the preliminary safety and immunogenicity profile of ReCOV in this FIH trial," said Dr. Liu Yong, Chairman and General Manager. "Prophylactic vaccines are still the most effective means to prevent SARS-CoV-2 infection and control the global pandemic. We are looking forward to providing a next-generation of COVID-19 vaccine with the potential in safety, efficacy and accessibility, and will advance ReCOV into larger clinical studies soon to evaluate its efficacy and safety."

This ongoing FIH trial is a randomized, double-blinded, placebo-controlled study to evaluate the safety, reactogenicity, and immunogenicity of 2 ascending doses of ReCOV, when administered as 2 intramuscular injections (with 21 days apart) in healthy subjects. Today Recbio reported partial unblinded data of safety, reactogenicity and immunogenicity for Cohort 1 (younger adults/ReCOV 20μg).

This cohort enrolled 25 participants who were 18 to 55 years of age. In the trial, the SARS-Cov-2-neutralizing antibody geometric mean titers (GMTs) were converted to WHO/NIBSC unit of IU/mL for comparisons of neutralizing antibody titers with those of other widely used vaccines. Recbio obtained GMTs of 1643.2 IU/mL for neutralizing antibodies at 14 days after two doses of ReCOV, with both seropositive rate (SPR) and seroconversion rate (SCR) as 100%, suggesting a promising efficacy of ReCOV in preventing SARS-COV-2 induced diseases. SARS-CoV-2 neutralizing antibodies were performed by central laboratory of the study (360Biolabs). According to a recent pre-print study1, the GMT of SARSCoV-2 neutralizing antibodies were 1404.16 IU/mL and 928.75 IU/mL 14 days after two doses for Moderna and BioNTech/Pfizer mRNA vaccines, respectively.

Notably, based on pooled human plasma from convalescent patients, WHO international standard (including 20/136, provided by National Institute for Biological Standards and Control [NIBSC]) was widely used to calibrate different diagnostic techniques.

Meanwhile, the cellular immunogenicity data showed that ReCOV could induce antigen-specific CD4+ T cell responses in younger adults, reflecting in IFN-γ and IL-2 production, an obvious trend toward Th1 phenotype was observed with a peak level of Th1 cytokines detected at Day 36 (14 days after the 2nd vaccination).

ReCOV was generally well tolerated with a good safety and tolerability profile. The majority of adverse events were mild in severity. No SAE or TEAE leading to early discontinuation, no abnormal vital signs/laboratory testing results with clinical significance.

Recbio developed three cutting-edge technology platforms for novel adjuvant development, protein engineering and immunological evaluation. Supported by these platforms, Recbio continue to discover and develop a full suite of innovative vaccine candidates, such as next-generation HPV, shingles and Flu vaccines.

Source:1. Yu-An Kung, et al. Antibody titers measured by commercial assays are correlated with neutralizing antibody titers calibrated by international standards. Antibody titers measured by commercial assays are correlated with neutralizing antibody titers calibrated by international standards | medRxiv

About 360biolabs®

360biolabs® is the leading and most comprehensive specialty laboratory in the Australia and New Zealand region. Their expert pharmacokinetic (PK) and pharmacodynamic (PD) assay services support small molecule, biologic, vaccine and other innovative therapeutic solutions to human health. A world class and industry experienced technical team, known for their ability to successfully deliver technically challenging assays, 360biolabs® supports global pharmaceutical and biotech companies in a diverse and growing range of therapeutic areas.

360biolabs® delivers global regulatory compliant assays and reports following ISO/IEC 17025, ISO 15189, OECD GLP, GCLP and ICH GCP with a focus on quality. For more information, visit www.360biolabs.com.

About Recombinant Two-Component COVID-19 Vaccine (ReCOV)

In May 2020, RecoBio, together with Jiangsu Provincial Center for Disease Control and Prevention ("Jiangsu CDC") and Taizhou Medical New & High-tech Industrial Development Zone, jointly developed a recombinant two-component COVID-19 vaccine(ReCOV). Under the guidance of Professor Fengcai Zhu from the Jiangsu CDC, the R&D team thoroughly optimized the vaccine using protein engineering and new adjuvant technologies, so that ReCOV has promising safety and strong immunogenicity against SARS-CoV-2 and variants of concern such as Delta. A series of comprehensive advantages such as better cross-protection against emerging variants, easy scale-up of production, cost advantages, worldwide accessibility, good preparation stability, and storage and transportation at room temperature which become a very competitive second-generation new COVID-19 vaccine.

About Recbio

Recbio is an innovative vaccine company founded in 2012. With the vision of "Become the Leader of Innovative Vaccine in the Future," Recbio takes "Protect Human Health with Best-in-Class Vaccines" as its mission. It has established three major cutting-edge technology platforms including novel adjuvants platform, protein engineering platform, and immunological evaluation platform. Recbio has a high-value vaccine portfolio consisted of HPV vaccine candidates, COVID-19 vaccine candidates, shingles vaccine candidates, influenza vaccine candidates, adults TB vaccine candidates etc. The core scientific team has more than 20 years of experience in the development and commercialization of innovative vaccines. For more information, please visit https://www.recbio.cn/.

Forward-Looking Statements

This news release may contain certain forward-looking statements that are, by their nature, subject to significant risks and uncertainties. The words "anticipate", "believe", "estimate", "expect", "intend" and similar expressions, as they relate to Recbio, are intended to identify certain of such forward-looking statements. Recbio does not intend to update these forward-looking statements regularly.

These forward-looking statements are based on the existing beliefs, assumptions, expectations, estimates, projections and understandings of the management of Recbio with respect to future events at the time these statements are made. These statements are not a guarantee of future developments and are subject to risks, uncertainties and other factors, some of which are beyond Recbio's control and are difficult to predict. Consequently, actual results may differ materially from information contained in the forward-looking statements as a result of future changes or developments in our business, Recbio's competitive environment and political, economic, legal and social conditions.

Source: Jiangsu Recbio Technology Co., Ltd.