Potential biomarker may predict HIV vaccine efficacy

Scientists have identified a biomarker that may be able to predict which patients will benefit most from a therapeutic HIV vaccine candidate being developed by a Norwegian company.
Further analysis of a Phase II study of therapeutic HIV vaccine candidate Vacc-4x revealed a potential biomarker associated with participants who experienced a more profound viral load reduction after receiving the vaccine.
St George's, University of London is collaborating with Bionor Pharma to study HIV-associated immune activation that drives disease progression.
Based on St George's work within this field, Bionor Pharma has developed a peptide (C5/gp41732-744) that can be used to detect antibodies against a part of the HIV envelope glycoprotein.

The presence of antibodies to this part of HIV has been associated with slowed disease progression in the absence of combination antiretroviral therapy (ART).
Researchers found that median HIV viral load reduction more than doubled among participants with high anti-C5/gp41732-744 antibody levels who received the HIV vaccine candidate.

Further study will be needed to confirm anti-C5/gp41732-744 antibody levels as a biomarker for improved response to Vacc-4x, researchers said.
"In spite of very effective drugs against HIV these need to be taken daily and have significant side-effects," said Professor Angus Dalgleish, of St George's, University of London.
"The ability to replace this daily medication with a vaccine that allows several months of being off medication, not to mention the enormous financial gains that would be delivered to health services, is a step closer with these preliminary results," Dalgleish said.

The results of the study were presented at the AIDS 2014 Conference in Melbourne, Australia.