The company found that Pennvax-GP plasmids delivered intradermally with Inovio’s Cellectra device triggered equivalent or superior immune responses in healthy volunteers compared to intramuscular delivery of the plasmids using the same device.
The data are part of a study supported by the HIV Vaccine Trials Network and the NIH’s National Institute of Allergy and Infectious Diseases.
The 94-person trial was designed to assess and optimize a four-dose regimen of the Pennvax-GP DNA vaccine in combination with a DNA encoded immune activator, IL-12.
Inovio reported that 96% of people receiving Pennvax-GP and IL-12 via intramuscular delivery experienced a CD4 + T cell response. The same percentage of participants receiving the vaccine via intradermal administration experienced a CD4 + T cell response, despite receiving a smaller dose than those who received the vaccine intramuscularly.
The company added that samples from participants followed for a full year showed that the immune responses lasted six months after the last vaccine dose.
“These are exciting results for an early-phase HIV vaccine; the immunogenicity of the Pennvax-GP vaccine is robust when given via the intradermal or intramuscular delivery methods but the intradermal was superior with respect to antibody responses. Intradermal vaccination may prove to be an important method of DNA vaccine delivery in the future,” Dr. Srilatha Edupuganti, who reported the study’s findings this week at the Research for Prevention Conference, said in prepared remarks.
“We are truly pleased to see these robust and durable immune response data, which are among the highest ever responses we’ve seen with an HIV vaccine, and they are remarkably consistent with our other vaccine data reported from our Ebola, Zika and MERS clinical trials in terms of demonstrating nearly 100% vaccine response rates with a very favorable safety profile. Furthermore, our newer and more tolerable intradermal vaccine delivery device showed that we can elicit very high immune responses at a much lower dose,” Inovio president & CEO J. Joseph Kim added.