- A Phase 1 study of an experimental coronavirus vaccine, begun Friday by Chinese biotech Clover Biopharmaceuticals, will also be a proving ground for two immune boosters developed by GlaxoSmithKline and Berkeley, California-based Dynavax.
- Clover, which is testing a protein subunit vaccine for SARS-CoV-2 infection, has partnered with both GSK and Dynavax to test whether adding the companies' vaccine adjuvants could improve the effectiveness of its shot.
- Both of the adjuvants from GSK and Dynavax are used in existing vaccines for influenza and hepatitis B, respectively, to enhance the immune response triggered by inoculation. Adjuvants could be particularly important in stemming SARS-CoV-2's spread as they may help companies develop a vaccine that's effective at lower doses, enabling wider distribution with the same drug supply.
Clover's vaccine joins a dozen others already in human testing across the world. But it's only the second protein subunit candidate to begin clinical trials, following one from Maryland-based Novavax, according to a database maintained by the World Health Organization.
Like most vaccines being developed for coronavirus infection, Clover's mimics the spike protein that's thought to be essential for SARS-CoV-2 to enter and infect human cells. Tests in animals have shown the vaccine, combined with adjuvants from GSK and Dynavax, spurred high levels of neutralizing antibodies, according to Clover.
The Chengdu, China-based biotech will now study its vaccine in 150 health volunteers in Perth, Australia, comparing GSK's adjuvant with Dynavax's.
Preliminary safety results, as well as immune response data, could be available by August, Clover said, putting the company several months behind front-running companies like Moderna and CanSino Biologics.
If early data encourages, Clover said it would begin a Phase 2/3 study before the end of the year. But, as the company's choice of location for its Phase 1 trial shows, Clover will likely have to venture further afield to test its vaccine in wider groups of people. Despite a recent outbreak in Beijing, China has reported relatively few new cases of coronavirus infection in recent weeks, making study of experimental vaccines difficult.
Clover's trial could give early signs, though, of how well adjuvants aid vaccination against SARS-CoV-2. GSK, for example, is contributing its adjuvant to a higher-profile vaccine partnership with Sanofi, as well as to several other groups working with the Coalition of Epidemic Preparedness Innovations.
The British drugmaker, which is not developing its own vaccine, aims to produce 1 billion doses of its pandemic vaccine adjuvant in 2021.
Clover's vaccine is the sixth developed by Chinese groups to enter Phase 1 testing.