This article is a summary, click here for the comprehensive version and HIV Background

UPDATED 18.11.2010:

After further analyses of the international, randomized, double-blind, placebo-controlled multi-center phase IIb study of Bionor Pharma's therapeutic HIV-vaccine candidate, Vacc-4x, the Company reports an unexpected statistically significant reduction in viral load (amount of HIV virus) at the end of the study period for patients on the vaccine compared to the placebo group.

The study was designed to test HIV-patients' ability to stay off anti-retroviral therapy (ART) after having been immunized with Vacc-4x. Although the study did not meet its primary endpoints, as announced October 1, the findings from the additional analysis discovered that treatment difference with regard to viral load was statistically significant both within the study period and when compared to the viral load prior to ever starting ART. In patients who received immunization, viral load never returned to its pre-ART level, which normally happens when being taken off ART.

Due to the new findings, the Company has reversed its decision to stop development of Vacc-4x. Along with upcoming immunological data, these findings are expected to become the basis for the future positioning of Vacc-4x as a viable therapeutic HIV-vaccine.

 

Vacc-4x Therapeutic Vaccine

Human immunodeficiency virus (HIV) is a lentivirus that causes acquired immunodeficiency syndrome (AIDS), a condition in humans in which the immune system begins to fail, leading to life-threatening opportunistic infections. HIV is transmitted through a body fluids containing HIV, such as blood and semen.

Today’s HIV treatment option consists of combination Antiretroviral Therapy (ART). These have severe side effects, lead to drug resistance which leads to the need for   new drug combinations. About 20% of HIV infected individuals experience poor immune reconstitution (low CD4+ counts) despite initiating ART.

Vacc-4x consists of four modified peptides derived from the protein that encases the genetic material of the virus. These are intradermally injected in combination with an adjuvant (Granulocyte-macrophage colony stimulating factor-GM-CSF). Vacc-4x targets dendritic cells and stimulate the proliferation of both CD4+ (helper) and CD8+ (killer) cells. The CD8+ cells acquire the ability to recognise infected cells expressing the same characteristics that are represented in the modified peptides. The Vacc-4x therapeutic vaccine therefore aims to stimulate cell-mediated immunity. This will help eliminate infected cells and maintain CD4+ T-cell counts. Vacc-4x treatment is associated with only minor side effects such as swelling at the injection site and short-term flu-like symptoms following injection.

Vacc-4x Primary Objective:

• For patients on ART, the goal of Vacc-4x is to sustain CD4 T-cell counts and functionality to allow for safe prolonged ART-free periods.

Other potential objectives for Vacc-4x may include

• Delaying the initiation of life-long antiretroviral therapy for newly infected individuals.
• Fulfilling an unmet medical need for the 20% patients that do not respond adequately to ART.