“Inovio’s clinical results to date show universal responses against unmatched virus strains and best-ever T-cell immune responses induced by a non-replicating vaccine. These desirable characteristics could have significant implications for various diseases and we now have multiple human studies progressing.”
Inovio's technology will eventually succeed. But you have to prove that the "antibody response is therapeutic" either before exposure to the disease, or during the course of the disease. The antibodies have to be "neutralizing towards the disease entity" in vivo. In the host that you intend to protect or treat. That proof of the technology can only be achieved in patients suffering from or highly exposed to the disease intended for treatment. Examples, any Hepatitis C vaccine must lower the circulating Hep C virus in the blood by a significant level, or (best case) make it disappear from the circulation. Know this one by heart because of my nephew.
For the latter (prevention) potential patients get vaccinated and then follow reasonable precautions not to become exposed to the disease and the vaccinated group gets statistically significantly less disease than non-vaccinated controls or (preferably) historic controls of what is the incidence (number who get the disease per 100,000 people) of the disease in the area where the clinical trial is being performed. With malaria, for instance, virtually every major city in sub-Sahara Africa knows how many new cases to expect per month. The disease has been around for the last 100 years and they know the rate of exposure and contraction of disease.
Those are the tests that Inovio, or any other vaccine company, must meet to get a BLA for a vaccine.