InnaVirVax, a biopharmaceutical company, has commenced a Phase II clinical trial evaluating the therapeutic properties of the VAC-3S vaccine when combined with standard antiretroviral therapy (ART) in the course of HIV-1 infection.
The primary objective of the trial is to evaluate antibody response to the VAC-3S vaccine, which has been built to induce a humoral immune response against a highly conserved region of the gp41envelope protein of the HIV-1 known as 3S.
VAC-3S that complements ART acts on the immune system via CD4+ T-cells, a major factor responsible for progression of the disease during HIV-1 infection.
The data available from human group studies and/or non-human primate models indicate that anti-3S antibodies are related to an increase in CD4+ T cells and a decrease of HIV viral reservoirs as well as HIV inflammatory biomarkers.
VAC-3S includes three distinct but covalently linked parts so as to optimize production of an immune response.
Secondary objectives of the trial include overall general and local tolerance as well as clinical safety, comprehensive assessment of the immunological endpoints, inflammatory biomarkers, HIV reservoir and also identify the vaccine's immunogenic characteristics.
A Phase I dose escalation trial of VAC-3S carried out previously in 33 patients living with HIV whose CD4 T-lymphocyte levels were higher than 200 mm3 and who were on ART, showed safety and offered data for dose selection.
Three VAC-3S doses will be compared in the randomised, double-blind, placebo-controlled Phase II trial, under which about 90 patients will be studied in France, Germany and Spain.
The trial is conducted among HIV-1 infected adults with viral load less than or equal to 50 copies/mm3 treated with ART, whose CD4+ T-cell count at screening is between 200 and 500 cells/mm3.
Initially a three-month base vaccination will be carried out following which 3-maintenance injections in two of three dosage groups and a six-month follow-up period.
