Clover Biopharmaceuticals’ current goal is to file approval submissions by the end of 2022. (Diy13/iStock/Getty Images Plus)
Clover Biopharmaceuticals is fighting to establish a toehold in the COVID-19 vaccine space. Having missed a string of regulatory filing targets, the Chinese biotech is pitching its first-generation adjuvanted protein vaccine as a “universal booster”—and touting antibody levels against the omicron BA.5 subvariant to make its case.
The latest data come from a phase 3 clinical trial that administered SCB-2019, a vaccine based on the original strain of the SARS-CoV-2 virus, as a booster shot to participants who had previously received two doses of an inactivated vaccine. Clover linked its shot to fivefold higher neutralizing antibodies against the BA.5 subvariant of omicron compared to a third dose of the inactivated vaccine.
Geometric mean titers against BA.5 increased from 37 to 240 by 14 days after the administration of SCB-2019 as a booster. That 6.5-fold increase compared favorably to the 1.6-fold increase in recipients of an inactivated booster, who on average saw their antibody titers rise from 30 to 48. Performance against BA.5 is very important, as it is now the dominant subvariant, accounting for 86% of U.S. cases.
“It is very encouraging to observe the consistently robust immune response against BA.5 elicited by SCB-2019 across populations, building foundational evidence for SCB-2019’s potentially critical role in addressing the continuing burden of COVID-19—including in countries and regions where inactivated vaccines have been widely used to date,” Nicholas Jackson, Ph.D., Clover’s president of global research and development, said in a release.
However, Clover is promoting the effect of SCB-2019 on protection against BA.5 at a time when vaccines specifically designed to protect against the subvariant are available in some regions. The biotech is aiming to occupy a different niche in the global vaccine market than Moderna and Pfizer but even so may struggle to make an impact. Clover’s stock is down 80% so far this year.
Shanghai-based Clover fell behind the front-runners in the COVID-19 vaccine race in the first year of the pandemic but still looked positioned to make an impact in parts of the world when it reported its phase 2/3 data one year ago. Gavi, the Vaccine Alliance struck a deal for 414 million doses of vaccine in the summer of 2021, and the stability of the shot suggested it could help the global immunization push.
Having outlined plans to seek conditional approval in China and the EU and start shipping the vaccine by the end of 2021, Clover suffered setbacks that caused its target to slip, including a manufacturing inspection by the World Health Organization that led the biotech to call in contractors. The current goal is to file approval submissions by the end of 2022.