Inovio says HIV vaccine sustained durable memory responses at month 12
Inovio Pharmaceuticals announced that its HIV vaccine, PENNVAX-GP, maintained durable and robust immune responses at month 12, a full six months after the last dose in a Phase 1 clinical study. Inovio previously reported that PENNVAX-GP elicited the highest overall levels of immune response rates ever demonstrated in a human study by an HIV vaccine. To potentially prevent and treat HIV, PENNVAX-GP consists of a combination of four HIV antigens designed to generate both antibody and T-cell responses and cover multiple global HIV strains. This breakthrough data was presented at a plenary session at the 2018 HVTN Full Group Meeting on May 14 in Washington, D.C. by the Protocol Co-Chair of the HVTN 098 study, Dr. Stephen De Rosa, Research Associate Professor, Laboratory Medicine at the University of Washington and Fred Hutchinson Cancer Research Center. The HVTN 098 trial is the first clinical study of PENNVAX-GP. The randomized, placebo-controlled multi-center study enrolled 94 subjects to characterize and optimize a four-dose regimen of PENNVAX-GP DNA vaccine administered by intradermal or intramuscular administration in combination with a DNA encoded immune activator, IL-12. More comprehensive immune analyses demonstrated that PENNVAX-GP generated HIV-specific CD4+ T cell and binding antibody response rates close to 100% when delivered with either CELLECTRA intramuscular or intradermal devices. For instance, 96% of participants receiving PENNVAX-GP and IL-12 via the IM route demonstrated a CD4+ T cell response while the same percentage of participants receiving the vaccine formulation via ID administration also displayed anti-HIV CD4+ T cell responses -- even though those vaccinated via intradermal administration received 1/5th the total dose compared to those vaccinated via the intramuscular device. The new data from subjects followed for a full one year of the study showed that the immune responses were maintained in most subjects at month 12 as evidenced by the durability of activated T cells as well as the magnitude of responder rates. Notably, the percentage of patients who had CD8+ T cell responses immediately after the last dose stayed the same or even increased slightly over the 6 month follow up period, clearly demonstrating durable vaccine-generated memory responses. These results are from a study supported by the HIV Vaccine Trials Network and the National Institute of Allergy and Infectious Diseases, part of the National Institutes of Health in collaboration with Inovio.