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Antiretroviral Pre-Exposure Prophylaxis for HIV-1 Prevention among Heterosexual African Men and Women: The Partners PrEP Study. Jared Baeten, MD PhD & Connie Celum, MD MPH on behalf of The Partners PrEP Study Team IAS 2011. Study Funder: Bill & Melinda Gates Foundation. Background.
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Antiretroviral Pre-Exposure Prophylaxis for HIV-1 Prevention among Heterosexual African Men and Women: The Partners PrEP Study Jared Baeten, MD PhD & Connie Celum, MD MPH on behalf of The Partners PrEP Study Team IAS 2011 Study Funder: Bill & Melinda Gates Foundation
Background • The Partners PrEP Study is a phase III, randomized, double-blind, placebo-controlled, three-arm trial of daily oral tenofovir (TDF) and emtricitabine/tenofovir (FTC/TDF) PrEP for the prevention of HIV acquisition by HIV seronegative partners in heterosexual HIV serodiscordant partnerships
4758 HIV serodiscordant couples (HIV+ partner not yet medically eligible for ART) Randomize HIV- partners (normal liver, renal, hematologic function) TDF once daily FTC/TDF once daily Placebo once daily Follow couples for up to 36 months 1° endpoint: HIV infection in HIV- partner Co- 1° endpoint: Safety Partners PrEP Study All receiving comprehensiveHIV prevention services
Partners PrEP Study: Sites Eldoret, Kisumu, Nairobi, Thika, Kenya Jinja, Kabwohe, Kampala, Mbale, Tororo, Uganda
Study Procedures • HIV- participants • Monthly HIV & pregnancy testing • Monthly symptom & 3-monthly laboratory safety monitoring • Monthly provision of study medication and individualized adherence counseling, including not sharing study drug • HIV+ participants • 3-monthly visits • 6-monthly CD4 counts • ongoing HIV primary care • active referral for ART, following national guidelines
Study Procedures • HIV- participants • Monthly HIV & pregnancy testing • Monthly symptom & 3-monthly laboratory safety monitoring • Monthly provision of study medication and individualized adherence counseling, including not sharing study drug • HIV+ participants • 3-monthly visits • 6-monthly CD4 counts • ongoing HIV primary care • active referral for ART following national guidelines • All participants: comprehensive HIV prevention package • Risk reduction counseling (individual and couple) • Free condoms and condom counseling • Contraception counseling and provision • Screening and treatment for STIs • Counseling & referral for other HIV prevention interventions (e.g., male circumcision), per national policies
Interim monitoring • Independent Data and Safety Monitoring Board (DSMB) review every 6 months • Interim reviews of efficacy conducted August 2010 & March 2011 • Monitored with Lan-DeMets modification of O’Brien-Fleming interim monitoring • Pre-specified conservative stopping criteria, against H0=0.7 • During Closed Session in March 2011 meeting, DSMB observed strong trend for HIV protection on PrEP arms • Determined ad hoc meeting may be required before scheduled interim review • Meeting called for 10 July 2011; study team informed shortly before meeting • DSMB meeting on 10 July 2011 reviewed data through 31 May 2011 • DSMB recommended 1) study results be publicly reported & 2) the placebo arm be discontinued, because of clear demonstration of HIV protection from PrEP
Population characteristics * 11 couples found after randomization to be ineligible and exited from the study
Adherence • Primary measure of adherence = monthly pill count of unused study product
Pregnancy • Among HIV- women (n=1785): Hormonal contraceptive use at most recent study visit: 10% OCP, 26% injectable, 8% implant
HIV seroconversion endpoints 90 HIV acquisition events for ITT analysis (as of 31 May 2011) 12 HIV infected at enrollment 78 HIV acquisition events in primary study (mITT) analysis
Primary efficacy results • Primary analysis: modified intention-to-treat (mITT) • excluding infections present at randomization (3 TDF, 3 FTC/TDF, 6 placebo) ITT analysis results similar
Primary efficacy results • Primary analysis: modified intention-to-treat (mITT) • excluding infections present at randomization (3 TDF, 3 FTC/TDF, 6 placebo) Effect of TDF and FTC/TDF statistically similar (p=0.18) ITT analysis results similar
Primary efficacy results TDF FTC/TDF Placebo
Subgroup analysis - gender • Both TDF and FTC/TDF significantly reduced HIV risk in both men and women Women: 42 total infections: 8 TDF, 9 FTC/TDF, 25 placebo Men: 36 infections: 10 TDF, 4 FTC/TDF, 22 placebo
Safety • No statistically significant difference in deaths, SAEs, key laboratory AEs
Tolerability • Monthly 19-item symptom questionnaire
Sexual behavior • At enrollment, 27% of couples reported unprotected sex in the past month.
Sexual behavior • At enrollment, 27% of couples reported unprotected sex in the past month. This declined during follow-up and was similar across the study arms.
Sexual behavior • At enrollment, 27% of couples reported unprotected sex in the past month. This declined during follow-up and was similar across the study arms. One-third reported an outside partner during the study: 34% TDF, 33% FTC/TDF, 33% placebo
Ongoing testing • Testing ongoing for the following, not yet available: • HIV resistance in seroconverters • HIV plasma viral load in seroconverters • Plasma / intracellular drug levels in seroconverters and subset of non-seroconverters
Summary • TDF and FTC/TDF PrEP definitively reduced risk of HIV acquisition, by 62% & 73%, respectively, in African men and women • Similar efficacy between TDF & FTC/TDF • HIV protection effect was robust in both women and men • Study announcing findings 1.5 years earlier than expected • TDF and FTC/TDF PrEP were safe & well- tolerated • Mild gastrointestinal side effects, predominantly in Month 1 • No evidence of risk compensation
Next steps • Partners PrEP Study is continuing: • DSMB strongly recommended blinded continuation of the active PrEP arms, to continue to gather comparative information on the efficacy, safety, tolerability and resistance with TDF vs. FTC/TDF PrEP • Placebo arm participants currently stopping study medication. Thereafter, placebo arm will be offered active PrEP at the research clinics. • Demonstration projects for PrEP are needed, including as part of evaluations of evidence-based combination HIV prevention
Partners PrEP Study Team • University of Washington Coordinating Center • Connie Celum (PI), Jared Baeten (Co-Chair and Medical Director), Deborah Donnell (Statistician), Justin Brantley, Tami Cloutier, Robert Coombs, Amy Dao, Shauna Durbin, Mira Emmanuel-Ogier, Lisa Frenkel, Carlos Flores, Harald Haugen, Renee Heffron, Ting Hong, Jim Hughes, Erin Kahle, Johanna Karas, Becky Karschney, Lara Kidoguchi, Meighan Krows, Matt Leidholm, Jai Lingappa, Toni Maddox, Angela McKay, Julie McElrath, Allison Mobley, Susan Morrison, Nelly Mugo, Andrew Mujugira, Vikram Nayani, Patrick Ndase, Apollo Odika, Hilda O’Hara, Dana Panteleeff, Jennifer Revall, Marothodi Semenya, John Sparkman, Kathy Thomas, Ellen Wilcox • Sites • Eldoret, Kenya (Moi U, Indiana U): Edwin Were (PI), Ken Fife (PI), Cosmas Apaka • Jinja, Uganda (Makarere U, UW); Patrick Ndase (PI), Elly Katabira (PI), Fridah Gabona • Kabwohe, Uganda (KCRC): Elioda Tumwesigye (PI), Rogers Twesigye • Kampala, Uganda (Makarere U): Elly Katabira (PI), Allan Ronald (PI), Edith Nakku-Joloba • Kisumu, Kenya (KEMRI, UCSF): Elizabeth Bukusi (PI), Craig Cohen (PI), Josephine Odoyo • Mbale, Uganda (TASO, CDC): Jonathan Wangisi (PI), Jim Campbell (PI), Jordan Tappero (PI), Akasiima Mucunguzi • Nairobi, Kenya (KNH/U Nairobi, UW): James Kiarie (PI), Carey Farquhar (PI), Grace John-Stewart (PI), Harrison Tamooh, Freda Kinoti • Thika, Kenya (KNH/U Nairobi, UW): Nelly Mugo (PI), Kenneth Ngure • Tororo, Uganda (CDC, TASO): Jim Campbell (PI), Jonathan Wangisi (PI), Jordan Tappero (PI), Aloysious Kakia • DF/Net (data center): Lisa Ondrejcek, Darryl Pahl, Jae Chong • CLS (laboratory oversight):Wendy Stevens, Charlotte Ingram, Ute Jentsch, Mukthar Kader, Nombulelo Gqomane, Feroza Bulbulia, Jan van den Heuvel • ClinPhone/Perceptive Informatics (randomization) • Gilead (study drug): Jim Rooney, Raj Sangha, Abboud Habr, Farideh Said • Bill & Melinda Gates Foundation (study funder): Stephen Becker • HIV serodiscordant couples who test, screen, & participate