Treatment as Prevention ( TasP )
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Transcript of Treatment as Prevention ( TasP )
Treatment as Prevention (TasP)
Dr Michael BradyMedical Director, Terrence Higgins Trust
Consultant, HIV & Sexual Health
Reducing onward transmission: Viral suppression among key population groups living with HIV in the United Kingdom. 19th Annual Conference of the British HIV Association (BHIVA) April 2013, Valerie Delpech, Alison Brown, Stephano Conti, Venkata Polavarapu, Zing Yin
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Efficacy0% 10 20 30 40 50 60 70 80 90 100%
Effect size (95% CI)
Tenofovir/Truvada for discordant couples 73% (49; 85)
Study
Medical male circumcision 54% (38; 66)
Prime boost Vaccine 31% (1; 51)39% (6; 60)Tenofovir vaginal
(coital)
Truvada for MSMs 44% (15; 63)
96% (73; 99)Treatment for prevention
Truvada for heterosexuals 63% (22; 83)
Truvada for women 0% (-69; 41)
Tenofovir gel (daily)for women
15% (-20; 40)Truvada for women 0% (-50; 30)
Stable, healthy, serodiscordant couples, sexually activeCD4 count: 350 to 550 cells/mm3
Primary Transmission EndpointVirologically-linked transmission events
Primary Clinical EndpointWHO stage 4 clinical events, pulmonary tuberculosis, severe
bacterial infection and/or death
HPTN 052 Study Design
Immediate ART CD4 350-550
Delayed ART CD4 <250
Randomization
Total HIV-1 Transmission Events: 39
HPTN 052: HIV-1 Transmission
Linked Transmissions: 28
Unlinked or TBD Transmissions: 11
p < 0.001
Immediate Arm: 1
Delayed Arm: 27
• 18/28 (64%) transmissions from infected participants with CD4 >350 cells/mm3
• 23/28 (82%) transmissions in sub-Saharan Africa
• 18/28 (64%) transmissions from female to male partners
96% reduction in HIV Transmission
HIV Treatment GuidelinesGuideline Recommended CD4 at start of therapy
WHO (2013) < 500
BHIVA (2013) < 350Respect decision if patient wants to
start to reduce transmission
DHHS - USA (2012) All irrespective of CD4 count
IAS (2012) All irrespective of CD4 count
EACS (2013) <350Consider 350 – 500 and >500
Reducing onward transmission: Viral suppression among key population groups living with HIV in the United Kingdom. 19th Annual Conference of the British HIV Association (BHIVA) April 2013, Valerie Delpech, Alison Brown, Stephano Conti, Venkata Polavarapu, Zing Yin
Distribution of viral load among gay men living with HIV in the UK in 2010
HIV treatment as prevention among men who have sex with men in the UK: is transmission controlled by universal access to HIV treatment and care?AE Brown*,ON Gill, VC Delpech, Article first published online: 28 July 2013, HIV Medicine, Volume 14, Issue 9, pages 563–570, October 2013
What is the potential impact of starting treatment early?
• ART started at CD4 <500 could have reduced the proportion of PLWHIV with detectable viraemia from 42% to 38%
• Halving the undiagnosed population could have led to to a decrease to 28%
“Unlikely early treatment will reduce HIV transmission unless undiagnosed population is
substantially reduced”Brown et al AIDS 2014 Jan 14;28(2):281-3
What is the potential impact of starting treatment early?
• Extending ART to all diagnosed HIV infected MSM with CD4 <500 in 2010 would reduce proportion of infectious men from 35% – 29%.
• Halving the proportion who are undiagnosed would further reduce this to 21%
“The effectiveness of treatment as prevention will be limited unless the undiagnosed population is reduced through frequent HIV testing and consistent condom
use”
Brown et al AIDS 2014 Jan 14;28(2):281-3
Can we afford it?
• Estimated annual population treatment and care costs:– £104 million in 1997– £483 million in 2006– £721 million in 2013
Mandalia et al PLoS One 2010; 5:e15677
Summary: TasP
• The best evidence for effectiveness of an intervention to reduce transmission
• Effectiveness depends on knowing HIV status and therefore interlinked with testing strategies
• Cost may prohibitive
With limited resources do we
focus on:
ART for HIV positive people?
ART for HIV negative people?
Reduced transmission?cost
?adherence?sexual behaviour
?other STIs
Reduced transmissionReduced morbidityReduced mortality
Better quality of lifeLow pill burden
Low toxicity