Inovio Pharmaceuticals suggested that preliminary safety data from an ongoing phase 1 trial indicates that its experimental COVID-19 DNA vaccine candidate INO-4800 appears to be safe in humans.
“We are already seeing safety data and it has been benign,” commented R&D head Katherine Broderick, noting that some participants developed “slight redness of the arm.” The company also reported that INO-4800 induced neutralizing antibodies and T-cell responses against SARS-CoV-2 in a preclinical study, sending shares up as much as nearly 23% on the news.
The phase 1 clinical trial, which began in April, enrolled 40 healthy adult volunteers in the US who will receive two doses of INO-4800, given 4 weeks apart. Once preliminary results are in, likely next month, Broderick said Inovio expects to approach the FDA for authorization to move into a phase 2/3 trial, which could happen in July or August.
Meanwhile, in the preclinical trial, researchers immunized mice and guinea pigs with INO-4800, and then measured antigen-specific T-cell responses, functional antibodies that neutralize the SARS-CoV-2 infection and block Spike protein binding to ACE-2 receptors, and biodistribution of SARS-CoV-2 targeting antibodies to the lungs. Aside from observing virus neutralizing activity, investigators also detected antibodies in the lungs of the vaccinated animals. “Lower respiratory disease (LRD) is associated with severe cases of COVID-19. The presence of antibodies at the lung mucosa targeting SARS-CoV-2 could potentially mediate protection against LRD,” they noted.
Broderick said the preclinical findings, which were published Wednesday in Nature Communications, “build on our previously reported positive Phase 1/2a data from our vaccine against the coronavirus that causes MERS, which demonstrated near-100% seroconversion and neutralisation from a similarly designed vaccine, INO-4700.” She said Inovio plans to test the vaccine in larger animals, including rabbits and monkeys, while also undertaking challenge studies in mice, ferrets and monkeys.
The news follows preliminary data released this week showing that Moderna’s COVID-19 vaccine candidate mRNA-1273 generated neutralising antibodies in eight initial participants in an ongoing Phase 1 trial. Moderna’s announcement drove up shares as much as 24%, but a report highlighting the early nature of the data pulled down the stock value a day later.