Using anti-hiv drugs for prevention

Transcription

1 Using anti-hiv drugs for prevention Highlights from AIDS 2012 (and 2 nd International Workshops on Treatment as Prevention) Tim Rogers, trogers@catie.ca

2 Using anti-hiv Drugs for Prevention Outline Treatment as Prevention Pre-exposure prophylaxis (PrEP)

3 Treatment as Prevention Treatment as prevention is based on two streams of emerging research Earlier HIV treatment for people living with HIV may improve their long-term health Reducing viral load to undetectable through HIV treatment may reduce onward transmission of HIV

4 HPTN052 Trial : Proof of Concept ~1,800 heterosexual serodiscordant couples HIV-positive partner CD4 count between cells; not started treatment Willing to start treatment earlier than recommended by guidelines HIV-positive partner randomized to either 1. Immediate group Start treatment immediately (CD4 count higher than 350) 2. Delayed group Delay treatment until CD4 count drops below 250 cells Risk of HIV transmission 96% lower among couples in the immediate group versus the delayed group

5 HPTN052 Trial: More results There were 2 (partner-related) transmissions among people on treatment and in both cases viral load was not yet undetectable Upto 30% of new infections were not from primary partners Earlier treatment benefitted people with HIV: delayed progression to AIDS and reduced TB events For those who delayed ART (21%) it is hard to recover CD4 counts 93% of people with HIV enrolled in trial are now on ART

6 Ongoing Research on Treatment as Prevention Systematic review of transmission among heterosexual couples (7 observational studies) 66% reduction in HIV transmission for couples on treatment [MOPDC0105] Research underway Over 51 studies planned/underway, including 25 RCTs Canada, US, Swaziland, Botswana, China, South Africa, Nigeria... Mathematical modelling studies Show that TasP can have a big impact on the epidemic. The more complex (and potentially more real) the less predicted impact of TasP

7 What does a treatment as prevention program look like? Overall goal is to increase the number of people living with HIV who have an undetectable viral load Involves improving engagement and linkage across all steps of the HIV continuum of care HIV testing Linkage to care Retention in care Antiretroviral treatment Adherence support

8 Centers for Disease Control and Prevention (CDC). MMWR Morb Mortal Wkly Rep Dec 2;60(47):

9 Concerns with treatment as prevention Decisions to test and treat HIV must be made with appropriate information, counselling and informed consent We don t know yet the best time to start HIV treatment for the benefit of people living with HIV (research evidence is increasingly supportive of earlier treatment). Concerns about increased toxicity and/or difficulty maintaining long-term adherence People living with HIV should not be pressured into starting treatment for the sake of public health. Reducing HIV transmission is a shared responsibility

10 Concerns with treatment as prevention Treatment as prevention is not a silver bullet. We need to continue traditional prevention work, including addressing social drivers of HIV Poor adherence or increases in sexually transmitted infections could undermine prevention efforts and/or lead to increased HIV drug resistance We don t know how effective treatment as prevention will be for other groups, such as MSM and people who inject drugs ultimately treatment as prevention is the argument for universal access [to treatment] in the developing world regardless of the guidelines for starting -- Montaner

11 Towards the integration of Treatment and Prevention WHO guidance on HIV testing and counselling, including antiretroviral therapy for treatment and prevention in serodiscordant couples, 2012 IAPAC guidelines for improving entry into and retention in care and antiretroviral adherence for persons with HIV, 2012 CATIE in partnership with national and regional organizations will be undertaking a series of initiatives to look at how HIV treatment and HIV prevention can be synergistic and mutually reinforcing aspects of an integrated response

12 What is pre-exposure prophylaxis or PrEP? The ongoing use of one or two antiretrovirals by HIV-negative individuals starting before an exposure and continuing afterwards A potential option to prevent infection from ongoing exposures to HIV during periods of risk A recently proven strategy still being studied PrEP is currently unapproved by Health Canada

13 What PrEP research is happening? Large studies Oral pill taken daily (tenofovir, tenofovir/ftc) Tenofovir vaginal gel used before/after sex or daily Small Studies Gels used rectally Pills used intermittently or before/after sex Slow-release intravaginal rings Long-lasting injections Antiretrovirals other than tenofovir and emtricitabine

14 What is involved in a PrEP program? Comprehensive PrEP assessment, counselling and provision of medications Recruitment, assessment of HIV risk, HIV testing, counselling and informed consent, provision of medications Comprehensive package of prevention services Free condoms Adherence counseling STI testing and treatment Risk-reduction counseling HIV testing and counseling Comprehensive monitoring HIV status and number of HIV transmissions Adherence, side-effects, drug resistance, risk behavior

15 Does PrEP work? Several trials have shown PrEP can be partially effective [Caprisa, iprex, TDF2, Partners PrEP] 39%-75% reduction in HIV transmission Women, MSM and heterosexual couples Some trials have not demonstrated effectiveness [FEM PrEP, some arms of VOICE] In FEM PrEP, 70% of women did not think they were at risk for HIV infection (despite 5% incidence rate) Excellent adherence and accurate perception of risk are very important for PrEP to work

16 How might PrEP fit within existing treatment and prevention programs PrEP is not lifelong, but only for a season of vulnerability During conception Young MSM For cases of partner violence Newly diagnosed couples before treatment reduces viral load

17 Concerns with PrEP PrEP is very resource intensive and may compete with other prevention and treatment priorities We don t know how effective PrEP will be in the real world -- side effects, risk compensation, difficulty with adherence There is a risk that PrEP use may result in an increase in drug resistant HIV which could undermine treatment programs

18 Moving forward with PrEP US regulators (FDA) have approved Truvada for the prevention of HIV for HIV-uninfected MSM, HIV-uninfected partners in serodiscordant relationships and other uninfected people at risk for sexual transmission of HIV US CDC is developing guidelines for the use of PrEP (interim guidelines for MSM and heterosexual people) WHO has released guidelines for PrEP demonstration projects Ongoing research: clinical trials, open label studies, demonstration projects

19 Community readiness for PrEP MSM in New York city (survey of 329 men) 38% reported knowledge of PrEP Approximately 1% used PrEP (2 men) [Poster, WEPE274] Frontline workers in Canada (survey of 160 people) 84% have some knowledge of PrEP 26% asked about PrEP in last year 11% know at least one person using PrEP [Unpublished]

20 Thank You! Tim Rogers For more information visit