ENCORE: an international study funded by the Gates Foundation

News | Published on 24 May 2013

ENCORE: an international study funded by the Bill and Melinda Gates Foundation and co-ordinated by The Kirby Institute

The Bill and Melinda Gates Foundation’s links with the Kirby Institute at the University of New South Wales date back to 2009, when Kirby researchers received an award of US$12.5 million. Four years after the original grant, preliminary results from the first 48 weeks of the ENCORE1 study will be presented at the 7th International AIDS Society Conference on Pathogenesis, Treatment and Prevention in Kuala Lumpur, Malaysia in July 2013. This substantial international study, led and co-ordinated by The Kirby Institute, will undergo analysis of data from the first 48 weeks in 2013, followed by final analysis in 2014.

ENCORE (for Evaluation of Novel Concepts in Optimization of antiRetroviral Efficacy) was a program originally designed to examine the safety and efficacy of lower doses of important antiretroviral drugs (ART). This was intended to allow donors, governments and non-government organisations to purchase more drugs, and also to ease the pressure on manufacturing capacity to meet the growing global demand for ART. The process of revising dose guidelines is called dose optimisation and is expected to lead to greater effectiveness and efficiencies in funding for treatment, care and prevention work. The program comprised three individual studies: ENCORE1, ENCORE2 and ENCORE3.

ENCORE1, which began in 2010 and will conclude in 2014, is being conducted in 38 clinical sites in 13 countries in Africa, Asia, Australia, Europe and Latin America. This large international, multicentre, randomised double-blind placebo-controlled trial has recruited 630 trial participants to compare the safety and effectiveness of a reduced dose of HIV therapy efavirenz, or EFV (400mg compared to 600mg)in combination with two other standard ART drugs in HIV-positive people who have not previously taken HIV therapy.The primary analyses will determine if lower doses are just as effective as standard doses. Further analyses will address a range of other issues including safety, tolerability and quality of life.

The program’s additional studies, ENCORE2 and ENCORE3, examined the pharmacokinetic characteristics of important ART in a small number of HIV-negative volunteers. These studies were designed to determine if the ART had characteristics when administered at lower doses that could be used in larger clinical trials. Results from these trials were published in medical journals in 2011 and 2012.

Drug therapy for HIV not only extends and improves the quality of life of people with HIV, it also may reduce the likelihood of that person infecting others. Consequently the roll-out of HIV drug therapy supports the work of HIV/AIDS prevention. The focus of care for HIV-infected people is the continued scale-up of access to ART, but the success of the roll-out of ART is putting enormous pressure on both the ability to pay for the drugs and the capacity to manufacture them. Alternative means of reducing the costs, such as changes to the manufacturing process, have been exhausted.

“We are very honoured and excited to receive this support from the Bill and Melinda Gates Foundation to lead this important work,” said Professor David Cooper, Director of the Kirby Institute.