Inovio’s PENNVAX-GP elicits an immune response in nearly 100% of trial participants.

An HIV vaccine could be within reach. Inovio’s PENNVAX-GP has proven highly effective in early-stage clinical trials, with data showing an immune response in almost every subject tested. Using their SynCon^® immunotherapy technology, the company’s PENNVAX-B immunization provides coverage against all major HIV-1 clades by specifically targeting the env, gag and pol antigens.

The DNA vaccine was tested in combination with an immune activator, IL-12. The trial consisted of four shots, which produced a T-cell immune response (CD4+ or CD8+) in 93% of those who had been vaccinated, or 71 out of 76 subjects in the Phase I trial.

Out of the evaluated participants, 94% demonstrated an antibody response (or 62 out of 66). Out of the group who were administered the PENNVAX-GP vaccine and IL-12 with intradermal immunization, a total of 96% (27 of 28) of the participants demonstrated an HIV env specific antibody response. A full 100% (27 out of 27) achieved a cellular response and 19 out of 21 (90%) demonstrated an env specific antibody response.

This was in stark contrast to those who received a placebo; none of the nine placebo candidates triggered an immune response. The trial was sponsored by the HIV Vaccine Trials Network (HVTN) and NIH’s National Institute of Allergy and Infectious Diseases. This is the first clinical study (dubbed the HVTN 098 trial) for the PENNVAX-GP immunotherapy.

The findings were released at the 2017 HVTN Spring Full Group Meeting, held in Washington D.C. on May 23^rd. Protocol Co-Chair of the HVTN 098 study, Dr. Stephen De Rosa, the Research Associate Professor of Laboratory Medicine at the University of Washington and Fred Hutchinson Cancer Research Center, presented the findings. Addressing the impressive outcome of the response to the vaccine in the study, Dr. De Rosa commented on the near perfect results of PENNVAX-GP in trials.

“The preliminary results of HVTN 098 are remarkable for a number of reasons. In HVTN 098, nearly all individuals vaccinated with the regimens including IL-12 had detectable CD4 responses and over half had CD8 T cell responses,” he stated. “Similarly, the antibody response rate was 100% or close to 100% for several of the env antigens tested in the assay. Thus, these high response rates are exceptional. Further studies will be needed to determine if this vaccine candidate can safely and effectively prevent HIV infection.”

A total of 94 subjects were enrolled in the HVTN 098 trial, with 85 receiving the vaccine either through intramuscular or intradermal delivery and with nine being given the placebo. One of the goals of the trial was to optimize routes of administration.

Inovio’s President & CEO, Dr. J. Joseph Kim, echoed the enthusiasm brought about by the trial results, noting that, “These results are among the highest ever responses we’ve seen with an HIV vaccine, and they are remarkably consistent with our recent data reported from our Ebola, Zika and MERS clinical trials in terms of demonstrating nearly 100% vaccine response rates with very favorable safety profile,” he described. “Furthermore, our newer and more tolerable intradermal vaccine delivery device showed that we can elicit very high immune responses at a much lower dose. We look forward to advancing PENNVAX-GP into later-stage clinical development with our partners and collaborators,” added Kim.     

The PENNVAX-GP has been the subject of interest for almost a decade now, having received financial backing from NIAID in 2009 with a $25 million award, as well as an additional $16 million grant in 2015, along with a five-year contract. Based off the release of the findings, Inovio’s stock shot up thirty percentage points.