Preparing for pre-exposure prophylaxis (PrEP) to prevent HIV infection

1. Preparing for pre-exposure prophylaxis (PrEP) to prevent HIV infection Dr. Carol Odula (Obs./Gyn.) May 7th 2013

2. Turning to antiretrovirals for prevention The use of antiretrovirals for prevention by… • HIV-positive individuals to reduce their risk of transmitting HIV • Treatment as prevention • HIV-negative individuals to reduce their risk of infection • Post-exposure prophylaxis (PEP) • Pre-exposure prophylaxis (PrEP)

3. What is pre-exposure prophylaxis (PrEP)? • Pre  Before (and after) • Exposure  When a fluid containing HIV comes into contact with mucous membranes or non-intact skin • Prophylaxis  An action taken to prevent infection or disease

4. What is PrEP to prevent HIV infection? • 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

5. How does PrEP work? • Infection does not occur instantly after an exposure to HIV • The virus needs to spread throughout the body • This may take up to 3 days after the exposure • The “window of opportunity” for PrEP • The brief period of time - after an exposure - where HIV has not yet spread throughout the body • During this time, PrEP may be able to stop HIV from causing an infection

6. Potential types of PrEP How are the antiretrovirals used? • Oral pill • Topical gel (microbicide) • Rectal • Vaginal • Injection • Intravaginal ring How often are the antiretroviralsused? • Daily • Intermittently • Coitally (before/sex) How many antiretrovirals are used? • Single • Combination What antiretrovirals are used? • Over 25 available

7. What concerns does the use of PrEP raise? • Side-effects and toxicity • Drug resistance • Adherence • Risk compensation • Access • Cost

8. What’s being researched? Large studies • Viread or Truvada pill taken daily • Viread Tenofovir • Truvada  Tenofovir+ Emtricitabine • 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 Tenofovirand Emtricitabine

9. How is the research conducted? Biomedical prevention trials • Enrollment criteria • Randomized • Placebo-controlled • Blinded Comprehensive package of prevention services • Risk-reduction counseling • Access to male and female condoms • Adherence counseling • HIV testing • STI diagnosis and treatment • Several outcomes measured • HIV infections • Adherence • Side-effects and toxicity • Risk behavior

10. What does the research say about PrEP? 10

11. Impact outside of a clinical trial • Uptake • How many people are using it? • Awareness – Do people know its available? • Acceptability – Do people want to use it? • Access – Can people access it if they want to? • Who is using it? • Adherence • Are people using it consistently and correctly? • Risk behavior • Are people increasing their risk behavior?

12. What we do know about PrEP? • In combination with a comprehensive package of prevention services… • Daily Truvada reduced the risk of infection when used by • MSM and trans women • Heterosexual men and women • Daily Viread reduced the risk of infection when used by heterosexual men and women • A vaginal tenofovir gel used before and after sex reduced the risk of infection when used by women. • It needs to be used consistently for it to work. • The risk of side effects, toxicity, and drug resistance are low.

13. What don’t we know about PrEP? • Safety/effectiveness of… • A pill taken occasionally • A gel used in the rectum • Long-lasting options (intravaginal ring or injection) • Other antiretrovirals • Safety/effectiveness of Viread, Truvada and tenofovir gel… • In populations not included in trials • Over a longer period of time • In the “real world”

15. There is no magic pill