Inovio Pharmaceuticals recently published the results of two HIV DNA vaccine studies. Both studies resulted in humoral immune responses, significant antigen-specific T-cell responses, and ultimately protection from the HIV virus.
The first study evaluated Inovio’s HIV DNA vaccine in non-human primates (monkeys). This novel genetic vaccine was designed to target clade C envelope protein using Inovio’s SynCon technology. Clade C is a sub-type of the HIV virus that is mostly prevalent in Africa, India, and China. Several more optimization steps were employed including codon/RNA optimization, addition of a Kozak sequence and implementation of an IgE leader sequence to enhance the expression of the vaccine in humans. The results of the first study were robust producing high levels of T-cell responses that were up to three times greater than T-cell responses from other comparable DNA vaccines that are currently targeting the HIV envelope, especially clade C. Inovio is planning two Phase I human studies to test the immunogenicity of this vaccine in humans in the U.S. and Africa.The second study was also conducted in non-human primates to asses the protective effects of Inovio’s PENNVAX HIV DNA Vaccines. Inovio used the monkey virus Simian Immunodeficiency Virus or SIV, which is comparable to the human HIV virus for their primate studies. The vaccine encoded three major proteins within the retroviral genome and was delivered using Inovio’s electroporation technology. Observations included several gene sequences that were differentially regulated in vaccine-protected groups compared to non-vaccinated animals. The results showed that Inovio’s PENNVAX vaccination increased production of several gene sequences, including those involved in interferon signaling as well as those involved in immune cell trafficking and cell cycle progression. This study also demonstrated that found that monkeys vaccinated with Inovio’s PENNVAX vaccine were protected from the SIV virus. The vaccinated animals demonstrated strong control of viral replication and had significantly lower viral load while also displaying significantly enhanced antigen-specific killer T-cell responses.