Advaccine Biopharma Suzhou and Sinovac Biotech will conduct two China trials of Sinovac's approved COVID-19 vaccine combined with US-based Innovio's (NSDQ: INO) DNA vaccine candidate for COVID-19. Earlier this year, Advaccine announced a $108 million agreement to acquire China rights to the Innovio vaccine. In animal testing, the combination of INO-4800 and Sinovac's CoronaVac, an attenuated vaccine, produced a higher response against the virus. Advaccine is sponsoring the trial.

Constructed of a precisely designed DNA plasmid, Innovio's INO-4800 is injected intradermally followed by electroporation via a proprietary smart device to deliver the DNA plasmid directly into cells in the body. The Advaccine-Innovio deal also out-licensed Advaccine's plasmid manufacturing process to Innovio.

Innovio believes INO-4800 can be used as a primary and a booster vaccine due to its tolerability, balanced cross-reactive immune responses and strong stability profile, which does not require cold or ultra-cold-chain transport. It is the only nucleic-acid based vaccine that is stable at room temperature for more than a year, according to the company.

INO-4800 has been shown to stimulate high-level of antigen specific binding antibodies, neutralizing antibodies by both live-virus neutralization assay and hACE2 receptor blocking assay, and antigen-specific T cell immune responses.

The studies will evaluate the safety, tolerability and immunogenicity of heterologous prime-boost sequential immunizations using INO-4800 and CoronaVac®, Sinovac's inactivated COVID-19 vaccine that has been validated by the World Health Organization (WHO) for emergency use. Both China studies are expected to begin this fall and will involve healthy adult subjects 18 years of age or older.

Dr. J. Joseph Kim, President and CEO of Inovio, said, "With the increased challenge of the highly contagious delta variant and other variants of concern around the world, our work with Advaccine and Sinovac is more important than ever. We are especially proud to expand on our partnership with Advaccine to explore heterologous prime-boosting using INO-4800 to protect more people in the continued fight against COVID-19.

Dr. Bin Wang, Founder and Chairman of Advaccine, said, "If approved, the development of heterologous prime-boost strategies for COVID-19 vaccines with different mechanisms of action is an important research direction in the field of vaccine applications. It provides an efficient solution to synergistically enhance the immunogenicity of vaccines, a key factor to fight against the current increase in global COVID-19 cases and variants of concern."

Previously, Inovio expanded its partnership with Advaccine to jointly conduct the global Phase III segment of the ongoing Phase II/III trial in multiple countries with an initial focus on Latin America, Asia and Africa. The primary endpoint will be virologically confirmed COVID-19 cases.

With the rise of the Delta variant of COVID-19, Innovio said a recent analysis showed that INO-4800 maintained a robust T cell level against the new strain, when compared to T-cell responses from the original wildtype strain. This data complements the Phase I and II trial data for INO-4800, which showed the ability to induce a balanced immune response that includes engagement of both T cells and B cells.

Innovio has also dosed the first participant in a Phase II trial for INO-4700, its DNA vaccine candidate for the prevention of Middle East Respiratory Syndrome (MERS), a coronavirus that is 100 times deadlier than COVID-19.

See our other articles on Advaccine and Sinovac.

Disclosure: none.