HIV Vaccine Elicits Nearly 100% Immune Response Rate in Clinical Trial

Pennvax-GP scores big for Inovio Pharma

The human immunodeficiency virus (HIV) vaccine Pennvax-GP has produced among the highest immune response rates (humoral and cellular) ever demonstrated in a human study by an HIV vaccine, according to a report from its developer, Inovio Pharmaceuticals. Pennvax-GP consists of a combination of four HIV antigens designed to cover several global HIV strains and to generate both a humoral (antibody) and a cellular (T-cell) immune response to potentially prevent and treat HIV infection.

The preliminary results were from a study supported by the HIV Vaccine Trials Network and by the National Institute of Allergy and Infectious Diseases, part of the National Institutes of Health, in collaboration with Inovio. The study evaluated a four-dose regimen of Pennvax-GP DNA vaccine administered by intradermal (ID) or intramuscular (IM) injection in combination with a DNA-encoded immune activator, interleukin (IL)-12 (INO-9012) among 94 subjects (85 vaccine, nine placebo).

Of 76 evaluable vaccinated subjects, 71 (93%) showed a CD4+ or CD8+ cellular immune response to at least one of the four vaccine antigens (env A, env C, gag, or pol). Similarly, 62 of 66 (94%) evaluated subjects demonstrated an env-specific antibody response. None of the nine placebo recipients showed either an antibody or a cellular response during the study.

Among the subjects receiving the Pennvax-GP vaccine and IL-12 via ID immunization, 27 of 28 (96%) demonstrated a cellular response, and 27 of 28 (96%) demonstrated an HIV env-specific antibody response. Similarly, among evaluated subjects receiving Pennvax-GP and IL-12 via IM vaccination, 27 of 27 (100%) demonstrated a cellular response, and 19 of 21 (90%) demonstrated an env-specific antibody response.

Similar immune responses and response rates were achieved via both ID and IM administration of the vaccine, although subjects in the ID group received one-fifth of the dose given to those in the IM group.

Source: Inovio Pharmaceuticals; May 24, 2017.