Shares of Inovio Pharma Rally Following News of Positive Response Rate from Next-Gen HIV Vaccine
Inovio Pharmaceuticals, Inc. (NYSE: INO) announced today the peer-reviewed publication of results from two phase I trials (HVTN 070 and HVTN 080) of its PENNVAX^®-B preventive HIV DNA vaccine delivered with a DNA adjuvant and with or without Inovio's proprietary CELLECTRA^® electroporation delivery device. The studies were conducted by the HIV Vaccine Trials Network (HVTN). Inovio's HIV DNA vaccine together with the CELLECTRA device significantly increased the number of responders producing robust and durable CD4 and CD8 T-cell responses in humans. The observation of robust T-cell responses against distinct targeted diseases generated by different Inovio SynCon® DNA vaccines delivered using CELLECTRA electroporation technology have now been published in two respected peer-reviewed journals. These results are compelling because T-cells are considered critical to fighting cancers and chronic infectious diseases.
While Inovio previously released preliminary data from these two trials, this comparison and durability data was published in the peer-reviewed Journal of Infectious Diseases in the article, "Safety and comparative immunogenicity of an HIV-1 DNA vaccine in combination with plasmid IL-12 and impact of intramuscular electroporation for delivery." The lead author was Dr. Spyros Kalams, who is Associate Professor of Medicine, Vanderbilt University Medical Center and principal investigator of Vanderbilt's HIV Vaccine Trials Unit for both clinical studies.
Robust T-cell responses were generated in 89% of the subjects that received three vaccinations of PENNVAX-B, which consists of 1 mg of each of three DNA plasmids (encoding for HIV gag, pol, and env proteins) along with 1 mg of IL-12 DNA plasmid, followed by intramuscular electroporation with Inovio's CELLECTRA device. Three or four vaccinations with a 2 mg dose of each PENNVAX-B plasmid plus 1.5 mg of IL-12 DNA generated fewer responses when delivered without electroporation.
Comparative T-Cell Response Rates: PENNVAX-B Plus DNA IL-12 With and Without CELLECTRA Electroporation (EP) Regimen CD4 CD8 Half dose, 3 vaccinations, with EP 80.8% (21/26) 51.9% (14/27) Full dose, 3 vaccinations, without EP 19.2% (5/26) 6.9% (2/29) Full dose, 4 vaccinations, without EP 40.7% (11/27) 3.6% (1/28)
Notably, using only half the vaccine dose, and only three doses as compared to four, CELLECTRA electroporation generated a 45% point increase (7% to 52%) in the generation of CD8 T-cells compared to the subjects that received a full dose without electroporation. In the three-vaccination regimen with electroporation, 88.9% (24/27) of subjects developed a robust CD4 or CD8 response. Six months after vaccination, T-cell response rates remained strong and persistent in the subjects that received only three doses delivered by CELLECTRA EP. Of 24 positive CD4 or CD8 T-cell responders following the third and last vaccination in month 3, 79% (19/24) showed persistent CD4 or CD8 T-cell responses at month 9. There were no safety issues observed when Inovio's DNA vaccine for HIV was co-administered with IL-12 DNA and delivered using electroporation with CELLECTRA.
CD4 and CD8 T-cells are both important in cellular immunity, however, CD8 T-cells are considered especially integral to fighting cancers and chronic infectious diseases. Achieving a robust CD8 T-cell response in a significant number of patients, i.e. a significant response rate, has been a particular challenge for HIV researchers. In this study, PENNVAX-B generated CD8 T-cell responses with significant magnitude (as measured by the validated HVTN assay).
In other study arms that did not achieve statistical significance, the use of IL-12 DNA appeared to positively impact T-cell response rates. The increased response rate only occurred when IL-12 DNA was delivered with electroporation. This effect may be further investigated in future studies of Inovio DNA vaccines delivered with electroporation.
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