HIV - Immunotherapy Program

Phase 1  Therapeutic Trial (Treatment Interruption in HIV infected patients). In early 2014, we completed a Phase 1 clinical trial (GV-TH-01) investigating the therapeutic use of GOVX-B11, a prime boost combination of a DNA priming vaccine followed by an MVA vaccine boost. GV-TH-01 was undertaken in patients on antiretroviral treatment (ART) to evaluate safety and vaccine-elicited T cell responses, and explore the ability of elicited CD8+ T cells to control viral rebound during analytical treatment interruption (TI). Nine men who began antiretroviral therapy (ART) within 18 months of seroconversion and had sustained plasma HIV-1 RNA <50 copies/mL for at least 6 months were enrolled. Median age was 38 years, median pre-ART HIV-1 RNA was 140,000 copies/ml and mean baseline CD4 count was 755/µl. Two DNA, followed by 2 MVA, inoculations were given 8 weeks apart. Eight subjects completed all vaccinations and TI. Clinical and laboratory adverse events were generally mild, with no serious or grade 4 events. The vaccinations did not reduce viral reservoirs and virus re-emerged in all participants during TI, with a median time to re-emergence of 4 weeks. During the vaccination phase of the trial, enhanced CD8+ T cells were elicited in 8 of 9 participants and enhanced CD4+ T cell in 5 of 9 participants. Antibody responses were boosted in 4 of 9 participants. Analyses during the treatment interruption phase of the trial suggested that individuals with the best immune responses had lower levels of re-emergent virus. These levels however were not sufficiently low to prevent immune escape. Excellent safety was observed throughout the trial, with none of the participants needing to reinstate antiretroviral drugs during the treatment interruption phase of the trial. The results of this trial are published in PLOSONE DOI:10:.1371/journal.pone.0163164 (2016).

GOVX-B11 is currently being made available to those who wish to test the immune responses elicited by this vaccine in conjunction with other modalities for achieving a cure.