START

What was this study about?

The aim of START was to determine if it is better for people with HIV to start anti-HIV drugs earlier than is current practice.

CD4+ cells form an important part of the immune system- they help coordinate the immune response by stimulating other immune cells to fight infection. HIV weakens the immune system by destroying CD4+ cells. So, the stronger the immune system, the higher number of CD4+ cells in the blood (CD4+ count). During the study the recommended guidance was for people with HIV start anti-HIV drugs when their CD4+ count drops to 350 (per microlitre).

Participants in START were people with HIV but with CD4+ count more than 500. The study compared the effects of starting anti-HIV drugs (antiretroviral therapy - ART) straight away when CD4+ count is more than 500 (immediate group) with delaying treatment until CD4+ count is less than 350 (deferred group) on disease progression and death in people with HIV. 

What difference did this study make?

START Results

Starting HIV treatment straight away, rather than waiting until the disease has damaged the person's immune system, reduces the risk of developing serious illnesses. The results from the START trial were presented on the 20th July 2015 at the International AIDS Society conference in Vancouver and published in the New England Journal of Medicine.

Antiretroviral therapy is very effective at treating HIV, but it does have side effects. Until now it has not been clear whether it is better for a person with HIV whose immune system is still intact to wait until their immune system had been weakened by the disease before starting treatment for life, or to start is as soon as possible. START is the first large-scale randomised controlled trial to establish that starting antiretroviral treatment straight away benefits HIV-infected individuals regardless of the state of their immune system.

Follow up phase 

Following the results of START all participants were offered treatment if they were not already on antiretroviral therapy, and initially were all to be followed as planned until 2016. Following additional funding the follow up was extended to address another important question:

'Are there long-term consequences from having delayed ART treatment?'

The START trial was uniquely placed to address this question reliably by comparing the immediate and deferred ART groups for rates of the START primary composite outcome for the calendar period 2016 to 2021.

The follow up data showed that among adults with CD4 counts >500 cells/mm³ , excess risk of HIV disease progression and serious non AIDS-defining complications associated with delaying treatment initiation was diminished after ART initiation, but persistent excess risk remained.

START infographic

Transparency Statement

START long-term benefits

 

Type of study

Randomised trial

Contact details

mrcctu.ctuenquiries@ucl.ac.uk

Who funded the study?

This trial is funded by the National Institute of Allergy and Infectious Diseases, USA.