Inovio Pharmaceutical’s DNA Vaccine for Zika Virus Induces Robust Immune Responses


Inovio Pharmaceuticals, Inc. recently announced that preclinical testing of its synthetic vaccine for the Zika virus induced robust and durable immune responses, demonstrating the potential for a SynCon vaccine to prevent and treat infections from this harmful pathogen. Health authorities have observed neurological and autoimmune complications potentially associated with Zika virus, including microcephaly in newborns and Guillain-Barre syndrome. Inovio is developing its Zika vaccine with GeneOne Life Sciences (KSE:011000) and academic collaborators.

“Using our SynCon technology, we rapidly generated a synthetic vaccine candidate that shows promise as a preventive and treatment. With robust antibody and killer T cell responses generated by our vaccine in mice, we will next test the vaccine in non-human primates and initiate clinical product manufacturing. We plan to initiate phase I human testing of our Zika vaccine before the end of 2016,” said Dr. J. Joseph Kim, Inovio’s President and CEO.

In this preclinical study, DNA vaccine constructs targeting multiple Zika virus antigens were synthetically generated using Inovio’s SynCon vaccine technology. These SynCon constructs were administered using Inovio’s CELLECTRA electroporation delivery technology. Inovio’s Zika DNA vaccine resulted in seroconversion, or the development of detectable specific antibodies in the blood, in all vaccinated mice. Researchers also observed that vaccination generated robust and broad T cell responses as analyzed by the standardized T cell ELISPOT assay. These findings are vital given the potential importance of neutralizing antibodies in preventing infection and the role T cells play in clearing infection by killing cells that harbor the virus.

Zika virus belongs to the flavivirus family, which includes dengue and West Nile virus (WNV). Inovio previously published robust immunogenicity and challenge protection data for its SynCon dengue and WNV vaccine candidates. Inovio’s Zika program builds on its extensive previous preclinical development experience with flavivirus-related vaccines.

First identified in Uganda, Zika virus subsequently spread to equatorial Asia and over the past 2 years has rapidly spread through the South Pacific, including Hawaii, and to South America, Central America, and the Caribbean. Zika virus is a flavivirus, a family of viruses including yellow fever, dengue, and West Nile virus, which are introduced to people through mosquito bites. Because the Aedes species of mosquitoes that spread Zika virus is found throughout the world there is concern that outbreaks will spread to new countries. There is also concern that Zika can spread sexually, as has been reported for some returning travelers. In February 2016, WHO stated that 39 countries had reported locally acquired circulation of the Zika virus since January 2007. Geographical distribution of the virus has steadily expanded.

The most common symptoms of Zika virus are fever, rash, joint pain, and conjunctivitis. More seriously, a possible link to a severe birth defect called microcephaly has recently been observed resulting from infected mothers. Microcephaly is a rare condition marked by an abnormally small head and incomplete brain development. There may also be a link with Guillain-Barré syndrome, a disease in which the body’s immune system mistakenly attacks peripheral nerves. Symptoms start with muscle weakness. In severe cases the person is almost totally paralyzed and the disorder can be life threatening.
No vaccine or therapy currently exists for the Zika virus.

GeneOne Life Science Inc. is an international DNA vaccine developer and leading contract manufacturer of DNA plasmid-based agents for preclinical and clinical trials for global companies and institutions. It researches and develops DNA vaccines to prevent and treat incurable diseases in South Korea and internationally. The company is headquartered in Seoul, South Korea. VGXI, Inc., GeneOne’s wholly owned manufacturing subsidiary located in Texas, is the largest pure-play cGMP DNA plasmid manufacturing facility in the world.

Inovio is taking immunotherapy to the next level in the fight against cancer and infectious diseases. It is the only immunotherapy company that has reported generating T cells in vivo in high quantity that are fully functional and whose killing capacity correlates with relevant clinical outcomes with a favorable safety profile. The company is advancing a growing clinical- and preclinical-stage product pipeline. Partners and collaborators include MedImmune, Roche, University of Pennsylvania, DARPA, GeneOne Life Science, Drexel University, NIH, HIV Vaccines Trial Network, National Cancer Institute, US Military HIV Research Program, and University of Manitoba. For more information, visit www.inovio.com.