410 likes | 425 Views
Pre-Exposure Prophylaxis: How to PrEP with Models of Men and Women. Robert M Grant, MD, MPH Sept 24, 2010. Maurice Cook ( EM Designs Group, Inc.). HIV Prevention. 3 new infections for every person starting ART Few Concepts Known
E N D
Pre-ExposureProphylaxis:How to PrEP with Models of Men and Women Robert M Grant, MD, MPH Sept 24, 2010 Maurice Cook (EM Designs Group, Inc.)
HIV Prevention • 3 new infections for every person starting ART • Few Concepts Known • Condoms, Education, Clean Needles, VCT, MTCTp, Circumcision for Heterosexual Men, Treatment • All underutilized, most controversial • Multiple Concepts Failed • Acyclovir, Diaphragms, Mass STI Treatment, Intensive Counseling, Polyanion Microbicides • No Surrogate Markers Known • Adherence can run ½ reported levels • Potential Beneficiaries • Would often rather stay in bed then “advocate” for prevention
"We are really groping in the dark" Salim S. Abdool Karim Quoted in the Washington Post, November 1, 2007
What I Heard(I may have been mistaken) • Pills are for sick people • We are not sick • HIV is one of many problems • Certainly NOT the most urgent • Violence, Poverty, Isolation are More Urgent • If you want to study us • Use our names • Studying sex workers in an era when “sex work” was a forbidden term was a non-starter
Treatment and PreventionSimilar Technology • Treatment may prevent transmission • Prevention enables treatment • Both may use pills • Indeed, the same pills • Evaluated with Randomized Clinical Trials • Intention to treat is primary
Prevention And Treatment Are Different in RespectsThat Bear Directly on Adherence
Prevention is Not Treatment:1) No Patients • Healthy people, notwithstanding… • Language That Pathologizes People • “risk groups” and “vulnerable groups” vs • gay men, transexuals, sex workers, etc • Language that Pathologizes Acts • “risk behavior” vs • Sex or work or community or procreation
Prevention is Not Treatment:2) No regimens • Treatment regimens can be optimized • In vitro activity suggest target level • Pharmacokinetics suggest dosing interval • Phase II studies narrow to few options • Phase IIb/III select the best option • Phase IV explore alternatives • Optimization Made possible by • Surrogate markers, small sample size
Prevention is Not Treatment:2) No Regimens • No surrogate markers for HIV prevention • Immune correlates not known • Minimum protective level not known • Target cells for activity not known • Safety parameters not always clear • Prevention Trials Are Large • few options evaluated
Counseling When There is No Regimen • “Adherence” to an optimized regimen • Does not apply to PrEP • In Prevention, we do not say • “Don’t use condoms unless you can use them everytime” • Also Applies to… • Communication with Partners • Use of HIV Tests • May Apply to Pill use as well.
Prevention is not Treatment3) Drug Resistance? • In treatment, the virus population has many billions of opportunities to generate resistance • partial adherence to nnRTIs/3TC allows replication to generate drug resistant mutants • Partial adherence to PIs may not be sufficient to select the drug resistant mutants. • In Prevention, the virus population clings to a few mls of genital secretions • it is unknown whether new mutations can be generated. • Starting PrEP in the window period of infection will select resistance
Daily PrEP Selected M184I/V Resistance in 2/6 Animals Wild type Resistent Not tested Garcia-Lerma et al, 2008
Absence of drug resistance in macaques failing iPrEP with oral Truvada (2 weekly doses) DM92X 1800 DM91 8 8 8 6 6 6 wt wt 4 wt Log10 RNA copies/ml 4 4 2 2 2 0 0 0 0 4 8 12 16 20 0 4 8 12 16 20 0 4 8 12 16 20 Weeks Weeks Weeks DK40 DL6V 35032 8 8 8 6 6 wt wt 6 wt Log10 RNA copies/ml 4 4 4 2 2 2 0 0 0 0 4 8 12 16 20 0 4 8 12 16 20 0 4 8 12 16 20 Weeks Weeks Weeks Wild type Not tested Garcia-Lerma et al, 2009
Adherence and Resistance Bangsberg et al 2004
Resistance and AdherenceConcerns For PrEP • Starting or Restarting PrEP • during the RNA+/Ab- window” • Expected to select resistance • Non-adherence to the daily regimen • Unclear effect on resistance • Depends on efficacy, drug levels, selection • Fear of resistance drives a high bar • People who miss doses may give up • People who miss doses when highly exposed may be told to give both up (sex and PrEP)
Prevention is Not Treatment:4) We undermine adherence in prevention These messages have been quoted back to us during qualitative research, as reasons for deferring pill use until efficacy is proven.
Prevention is Not Treatment:5) Synergies expected • Treatment Choices Are Often Exclusionary • TDF/FTC vs AZT/3TC • EFZ vs NVP • Selecting A means not selecting B • Prevention Choices Are Typically Complementary • Condom is useful for HIV/ contraception/ STIs • PrEP may protect weak vaccine responses • PrEP may attract people into STI Care
Reported Risk Behavior Declined WithOpen-LabelPost-ExposureProphylaxisand Counseling • Martin et al., AIDS 2004
Conclusion from SF: PEP and Risk Compensation • Martin et al., AIDS 2004
Air Bags and Seat Belts • Antagonisms assumed initially, but • Airbags and seat belt innovations are now motivators for purchase of new cars • Safety conscious people demand both. • Synergies Prevail
I B IMB • Specific IMB for Each Action State • People populated by multiple IMB processes • Condom use, Test Use, PrEP Use, Reporting Motivation Information Skills Behavior IMBot
I B A situated IMBot socializing with friends
I B IMBot navigating in stormy waters:poverty, violence,racism,homophobia,addiction,sexuality.
I B Oceanic View of Sex and Society • Dynamic • Complex • Unpredictable • Mysterious • Details matter little • IMBots can learn to navigate over rough seas • Rough seas are better avoided than studied
Models of Man • Herbert Simon (1916-2001) • Published 1956 • “Bounded Rationality” • Not Pathological Within Social Context • Nobel Prize 1978 • APA award 1993
Bounded Rationality and Organizational Decision-makingOrganizations. March and Simon, 1958 • Decisions Come From Where People Sit • The Social Situation Governs • Information availability • Perceptions • Motivation and goals • Learned Skills and Heuristics
I B Social view of Sexadapted from Gagnon Sexual Conduct 1973 • Sex, both desire and control, are social constructs • Some safer than others • Plans may be lost • Behavior constrained, but not determined. • Can be studied and understood
US Traditions in Sex Research • Kinsey • Biology, Narratives, Outlets • Sociological (Gagnon & Simon) • Social scripts • Shape both desire and control • National surveys • Women’s studies/LGBT studies • Development of ED Drugs • AIDS Research
On AIDS Research • John Gagnon • “None of these studies has been undertaken to understand sexual phenomena, but rather to measure risk of seroconversion and the effectiveness of prevention efforts… Such purely AIDS-driven work forces researchers to follow outbreaks of the epidemic rather than anticipate them. • Disease and Desire. 1989
In Their Communities “Let’s Communicate”
Community Based Prevention • Ecuador • Constitutional Protections for LGBT Communities • Boston • Specialized Health Care For LGBT Communities Both Highly Successful iPrEx Sites
Successful Prevention Initiatives • Condom Use in US Cities Early 1980s • “Love Carefully” Uganda 1990s • SeroPos Seroadaptive Behaviors Late 1990s • Common Characteristics • Grass Roots Initiatives • The Scripts Changed • Love Carefully • Be a rubber man • Acknowledge Sexual Goals
People Learn What They Need to Know:Will Intermittent PrEP Create a Need to Recognize Exposure and Plan for Sex? (HPTN 067)
Toward More Effective Prevention • Advocacy for Study Populations • Gay, Lesbian, Transgender • Sex workers • Drug Users • Discordant couples • Abused • Focus on Use, not Intention • Turn the Oceans into Roadmaps • Sex, society, violence, poverty • NIH NIS and CDC NCS? • Focus on Synergies, not Antagonisms
iPrEx Presentations on PrEP Pill Use • Lorena Vargas, INMENSA, Lima, Peru • Qualitative Research in Andes • Albert Liu, SF DPH • Qualitative Research in SF • Rivet Amico, U. Conn • Next Step Counseling
Many Thanks To • HPTN 067 Behavioral Working Group • Frits Von Griensven • Rivet Amico • Kata Chillag • Daniela Marks • Michael Stirrat • Andrew Forsyth • Scott Rose • Sponsors/Funders • Division of AIDS, NIMH, Gates, CDC • IPREX Pill Use Working Group • Rivet Amico • Albert Liu • Ed Wolf • Pedro Goicochea • Lorena Vargas • Vanessa McMahan • Social Approaches • Jeff McConnell • John Gagnon • David Halperin
HIV, Risk, Behavior, and Agency1st Meeting, San FranciscoJanuary 16th and 17th, 2008