Immunization With HIV-1 Peptides in Adjuvant for Treatment of Patients With Chronic HIV-infection

Overview

Treatment: Immunization with a peptide-mix of 17 Clusters of Differentiation number 8 (CD8) T cell minimal epitopes and 3 Clusters of Differentiation number 4 (CD4) T cell epitopes and a new adjuvant (CAF01). The vaccine should induce cellular immunity against human immuno-deficiency virus type-1 (HIV-1). Target group: Untreated healthy individuals with chronic HIV-1 infection who are not in antiretroviral treatment. Purpose: The primary purpose is to evaluate tolerability and safety of the vaccine. The secondary purpose is to evaluate the clinical effect of the vaccination treatment as measured by induction of new T cell immunity, lowering of HIV-1 ribonucleic acid (RNA) viral load in plasma, and improvement in the patient CD4 lymphocyte blood counts. Design: The experiment is designed as a single-blinded, placebo-controlled phase 1 clinical trial in HIV-1 infected individuals in Denmark. Numbers of individuals: 20 fully evaluable HIV-1-infected patients should enter the study (15 vaccine treated and 5 placebo(saline) treated controls). The hypothesis is that a redirection of cytotoxic T lymphocyte (CTL) immunity to selected relatively immune silent (subdominant) but conserved CTL targets on multiple sites in HIV-1 could provide a better immune control of the virus replication. This could result in lowering of viral load thereby prolonging the time to antiretroviral therapy.

The HIV-1 vaccine in this trial is designed to prevent disease in healthy already HIV-1 infected individuals not in anti-retroviral treatment by inducing a strong cellular immune response against several immune subdominant selected target points in the patient's HIV-1 virus. The vaccine treatment is not harmful but could potentially lower viral load and thus delay the time to acquired immuno deficiency syndrome (AIDS) disease or to the need of antiviral medicine and thereby limit the spread of HIV-1 in the population. The patient's cellular immune response can only partly control the HIV-1 infection and eventually leads to a destruction of the immune system, opportunistic infections, and ultimately death. Normally the natural HIV-1 infection does not provide adequate immunity and vaccines must therefore induce a more potent and broader and more rationally directed immunity. Individuals that have this kind of strong immunity have lower viral-load and live longer. The vaccine in this study is designed to develop this kind of potent cellular immunity against HIV-1, so the virus is controlled better by the individual and spread in the population is limited. This vaccine is designed to match most individual's cellular immune system (HLA tissue types) and several conserved target points in the individual's own HIV-1 virus. On the basis of our previous vaccine trial of HIV vaccination of HIV-infected individuals in Denmark and years of research, we have been able to develop this HIV-1 vaccine. Our vaccine contains 18 peptides (15 major histocompatibility complex class 1 (MHC-I) restricted CD8-t-cell epitopes and 3 MHC class-II restricted CD4 T-cell epitopes) in a mix and should induce cellular immune responses to several conserved target points identified in HIV-1. Our vaccine is composed of 18 peptides in a lipid based adjuvant Cationic Adjuvant Formulation number 1 (CAF01) composed of dimethyl-deoctadecylammonium (DDA) and trehalose-dibehenate (TDB) and is deemed safe and the technique is simple and also called 'peptide vaccination'. This and similar techniques have been tried in several studies against virus diseases around the world. We want to know to which degree it is possible to immunize already HIV¬ 1 infected individuals to prolong the healthy period and prevent disease before initiation of antiviral medicine or other treatments of AIDS. In the present immunization study, healthy HIV-1 infected individuals not in treatment in Denmark will be invited to participate. This vaccine study will examine the immune responses and effects of the vaccine on these healthy HIV-1-infected individuals. The first purpose is first to determine if there are any side-effects of the vaccine. From several trials on animals and humans and in our own recent HIV vaccination trial on HIV-1 infected individuals in Denmark, with very similar vaccine techniques (peptides in autologous Dendritic Cells (DC) no serious side-effects has been observed. The second purpose is to examine if the vaccine induces the expected immune responses in HIV-1 infected individuals and how it enforces and supplements the already existing 'own' immune response of the infected individual. Finally, a clinical beneficial effect (on viral load and CD4 counts) of our vaccine will be evaluated.