Tianjin, January 6, 2023 – CanSino Biologics Inc. (“CanSinoBIO” or “the Company”) (SSE: 688185, HKEX: 06185) recently announced encouraging clinical progress of its COVID-19 mRNA vaccine CS-2034 (the “CS-2034”), less than one year after its clinical trial approval in China, marking the Company’s latest achievement in vaccine research and development (“R&D”), as well as providing portfolio diversification.

This phase IIb clinical study on safety and immunogenicity showed that booster vaccination with CS-2034 can provide broader protection against COVID-19 infections by inducing high-titer neutralizing antibodies against multiple SARS-CoV-2 variants of concern identified by the World Health Organization, including Omicron, compared to homologous inactivated booster vaccination.

The study was randomized, blinded and parallel-controlled, with a total of 433 adult participants aged 18 and above, out of whom over 50% were aged 60 years and above. All participants had received 3 doses of inactivated COVID-19 vaccine with a 6-month interval prior to the trial. The participants were randomly assigned to 2 groups – with Group A further divided into 2 subgroups of 160 participants each: one with adults aged 18-59 years and the other over 60 years, randomized at a 3:1 ratio to receive a dose of CS-2034 (0.3 ml volume per dose) or a dose of COVID-19 inactivated vaccine (0.5 ml volume per dose). Group B was comprised of elderly participants aged 60 years and above who had received one dose of CS-2034.

Favorable Safety Profile for Elderly People

The safety analysis showed that 28 days post booster vaccination, the overall incidence of adverse events was mainly mild in severity. Notably, the safety profile of elderly participants is better than that of participants aged 18-59.   

Strong Neutralizing Antibody Response against Multiple SARS-CoV-2 variants

The study showed that 28 days following the booster vaccination, the neutralizing antibody levels against the original SARS-CoV-2 strain was 27-fold of those who had received a homologous inactivated vaccine booster. The neutralizing antibodies against the Omicron BA.1 and the BA.5 variants were also significantly higher than those induced by a homologous inactivated vaccine booster – 23 times and 29 times, respectively. In particular, the geometric mean titer (“GMT”) of neutralizing antibody titer in elderly participants on Day 7 post CS-2034 booster vaccination was 296 against the BA.5 variant, 23-fold of those who had been given homologous inactivated vaccine boosters.

In April 2022, CanSinoBIO received clinical trial approval for its COVID-19 mRNA vaccine in China. mRNA has significant advantages in the R&D process and production cycles, including fast, scalable and uniform production and can be applied to areas not limited to COVID-19 vaccine development.