Clover Presents Updated Durability and Booster Data for COVID-19 Vaccine Candidate at World Vaccine Congress Washington 2022

SHANGHAI, China, April 19, 2022 (GLOBE NEWSWIRE) — Clover Biopharmaceuticals, Ltd. (Clover; HKEX: 02197), a global clinical-stage biotechnology company developing novel vaccines and biologic therapeutic candidates, today announced additional positive data from two ongoing studies evaluating SCB-2019 (CpG 1018/Alum), which demonstrated durable protection through approximately six months following primary vaccination and robust immune responses in neutralizing Omicron and other variants of concern after a booster dose in an expanded data set involving over 100 participants. These data were announced as part of a larger presentation, Clover’s adjuvanted protein-based vaccine: efficacy against SARS-CoV-2 variants and duration of protection, delivered on April 18^th at the World Vaccine Congress Washington 2022.

“Data presented at the World Vaccine Congress continue to reinforce that SCB-2019 (CpG 1018/Alum) delivered high and durable protection against COVID-19 and strong immune responses against variants of concern in the booster setting, which in combination with a potentially best-in-field safety profile and standard refrigeration storage and transportation conditions, gives us confidence SCB-2019 (CpG 1018/Alum) is a potentially premium COVID-19 vaccine candidate that can be used for primary vaccination and potentially as a universal booster candidate,” said Dr. Nicholas Jackson, President of Global Research and Development of Clover. “COVID-19 remains a concern globally with continued variant-induced outbreaks. We continue to diligently focus on expediting our regulatory submissions and prepare for commercialization of SCB-2019 (CpG 1018/Alum) in China and around the world.”

Durability of Protection at Approximately Six Months Following Primary Vaccination Series 

New datasets from an extended follow-up analysis confirm earlier findings and show that SCB-2019 (CpG 1018/Alum) elicited high and durable protection in individuals at approximately six months after the primary vaccination series. The follow-up analysis involved more than 14,700 individuals without evidence of SARS-CoV-2 exposure, and more than 14,700 subjects with evidence of prior SARS-CoV-2 exposure.

In adults (18-59 years of age) with no history of SARS-CoV-2 infection, efficacy against any SARS-CoV-2 strain was maintained at 100% for severe COVID-19 and 95% against hospitalizations due to COVID-19, at approximately 6 months after the primary vaccination series. In the elderly population (>60 years of age), efficacy against any SARS-CoV-2 strain was maintained at 100% for severe COVID-19 and 100% against hospitalizations, at approximately six months after the primary vaccination series.

In individuals with prior SARS-CoV-2 infection, efficacy against any SARS-CoV-2 strain was 71% for any severity of COVID-19 after primary vaccination with SCB-2019 (CpG 1018/Alum) and no decline in clinical efficacy against COVID-19 was observed over the approximate six-month period. In this population, a rapid increase of neutralizing antibodies following the first dose of SCB-2019 (CpG 1018/Alum) was associated with clinical protection against COVID-19, which was maintained for approximately six months after the primary vaccination.

No safety concerns were observed in individuals dosed with SCB-2019 (CpG 1018/Alum) within the follow-up period. Clover will continue to analyze the data and report results as they become available.

Updated Heterologous Booster Data in an Expanded Data Set

• Boosting data against the prototype strain: A heterologous booster dose of SCB-2019 (CpG 1018/Alum) in individuals previously receiving two doses of AstraZeneca’s COVID-19 vaccine elicited approximately 4-fold higher levels of neutralizing antibodies against the prototype strain when compared to individuals receiving three doses of AstraZeneca’s vaccine. In this expanded population of 103 individuals, as compared to the initial data in 76 individuals announced in February 2022, SCB-2019 (CpG 1018/Alum) as a heterologous booster dose provided a strong recall response, demonstrating clear evidence of immune maturation.
• Booster data against Omicron and other variants of concern: A heterologous booster dose of SCB-2019 (CpG 1018/Alum) in individuals previously receiving two doses of AstraZeneca’s COVID-19 vaccine elicited approximately 3-fold higher levels of neutralizing antibodies against the Omicron variant when compared to individuals receiving three doses of AstraZeneca’s vaccine. In this expanded population of 120 individuals, as compared to the initial data in 79 individuals announced in March 2022, SCB-2019 (CpG 1018/Alum) showed a higher neutralizing antibody response against variants of concern, including Beta, Gamma, Delta and Omicron, in comparison to individuals receiving three doses of AstraZeneca’s vaccine.

 Clover expects to submit full findings from the studies to a peer-review publication in the near future.

About SCB-2019 (CpG 1018/Alum)
Employing the Trimer-Tag™ technology platform, Clover developed the SCB-2019 antigen, a stabilized trimeric form of the S-protein (referred to as S-Trimer™) based on the original strain of the SARS-CoV-2 virus. Clover created its COVID-19 vaccine candidate by combining SCB-2019 with Dynavax’s (Nasdaq: DVAX) CpG 1018 advanced adjuvant and aluminum hydroxide (alum).

About Clover Biopharmaceuticals
Clover Biopharmaceuticals is a global clinical-stage biotechnology company committed to developing novel vaccines and biologic therapeutic candidates. The Trimer-Tag™ technology platform is a product development platform for the creation of novel vaccines and biologic therapies. Clover leveraged the Trimer-Tag™ technology platform to become a COVID-19 vaccine developer and created SCB-2019 (CpG 1018/Alum) to address the COVID-19 pandemic caused by SARS-CoV-2.

For more information, please visit Clover’s website: www.cloverbiopharma.com and follow the company on LinkedIn.

Clover Forward-looking Statements
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Clover Biopharmaceuticals:

Cindy Min
SVP, Public Affairs
media@cloverbiopharma.com

Naomi Eichenbaum
VP, Investor Relations
investors@cloverbiopharma.com