Investigators report the vaccine demonstrated it was safe, well-tolerated, and immunogenic in all age groups.
Plymouth Meeting, PA-based Inovio announced its investigational COVID-19 vaccine, INO-4800, showed positive safety, tolerability and immunogenicity in its placebo-controlled and blinded phase 2 trial.
“Our Phase 2 results validate our initial COVID-19 phase 1 results in a larger population, which show that INO-4800 continues to be generally safe, well-tolerated and immunogenic in all studied age groups,” INOVIO Chief Scientific Officer Laurent Humeau, PhD, said. “The expanded data set enabled a clear dose selection to be made with 2.0 mg as the dose for the global phase 3 efficacy trial."
The primary endpoints for the trial were to evaluate the safety, tolerability and immunogenicity of INO-4800 in a two-dose regimen (1.0 mg or 2.0 mg) in a 3-to-1 randomization to receive either INO-4800 or placebo for each dose to identify optimal dosing for 2 age cohorts (18-50 years) and (51 years and older).
INO-4800 is composed of an optimized DNA plasmid, which is delivered directly into cells in the body via a proprietary smart device to produce a robust, safe and tolerable immune response. DNA medicines are composed of optimized DNA plasmids, which are small circles of double-stranded DNA that are synthesized or reorganized by a computer sequencing technology and designed to produce a specific immune response in the body. INO-4800 is the only nucleic-acid based vaccine that is stable at room temperature for more than a year, according to the company.
The trial enrolled approximately 400 participants at 16 US sites. Each dose was administered by intradermal injection followed by electroporation using INOVIO's Cellectra, its proprietary smart device.
Safety endpoints included systemic and local administration site reactions through 8 weeks post-dose one or 4 weeks post-dose 2. Immunology endpoints included antigen-specific binding antibody titers, neutralization titers, and antigen-specific interferon-gamma (IFN-γ) cellular immune responses after two doses of the vaccine. The geometric mean fold rise (GMFR) of binding and neutralizing antibody levels were statistically significantly greater in the 2.0 mg dose group versus the 1.0 mg dose group.
The vaccine was regarded as generally safe and well-tolerated. The majority of adverse events (AEs) were Grade 1 and Grade 2 in severity and did not appear to increase in frequency with the second dose. The number of participants experiencing each of the most common AEs did not differ between the two dosing groups.
The data for the phase 2 trial will be filed with the US Food and Drug Administration, and following concurrence to proceed from the government agency, the company plans to conduct a global phase 3 clinical trial for INO-4800.