On-Demand Preexposure Prophylaxis in Men at High Risk for HIV-1 Infection

BACKGROUND:

Antiretroviral preexposure prophylaxis has been shown to reduce the risk of human immunodeficiency virus type 1 (HIV-1) infection in some studies, but conflicting results have been reported among studies, probably due to challenges of adherence to a daily regimen.

METHODS:

We conducted a double-blind, randomized trial of antiretroviral therapy for preexposure HIV-1 prophylaxis among men who have unprotected anal sex with men. Participants were randomly assigned to take a combination of tenofovir disoproxil fumarate (TDF) and emtricitabine (FTC) or placebo before and after sexual activity. All participants received risk-reduction counseling and condoms and were regularly tested for HIV-1 and HIV-2 and other sexually transmitted infections.

RESULTS:

Of the 414 participants who underwent randomization, 400 who did not have HIV infection were enrolled (199 in the TDF-FTC group and 201 in the placebo group). All participants were followed for a median of 9.3 months (interquartile range, 4.9 to 20.6). A total of 16 HIV-1 infections occurred during follow-up, 2 in the TDF-FTC group (incidence, 0.91 per 100 person-years) and 14 in the placebo group (incidence, 6.60 per 100 person-years), a relative reduction in the TDF-FTC group of 86% (95% confidence interval, 40 to 98; P=0.002). Participants took a median of 15 pills of TDF-FTC or placebo per month (P=0.57). The rates of serious adverse events were similar in the two study groups. In the TDF-FTC group, as compared with the placebo group, there were higher rates of gastrointestinal adverse events (14% vs. 5%, P=0.002) and renal adverse events (18% vs. 10%, P=0.03).

CONCLUSIONS:

The use of TDF-FTC before and after sexual activity provided protection against HIV-1 infection in men who have sex with men. The treatment was associated with increased rates of gastrointestinal and renal adverse events. 

Below:  Kaplan–Meier Estimates of the Probability of HIV-1 Infection

Full article at:  http://goo.gl/YWXXBZ

By:  Molina JM, Capitant C, Spire B, Pialoux G, Cotte L, Charreau I, Tremblay C, Le Gall JM, Cua E, Pasquet A, Raffi F, Pintado C, Chidiac C, Chas J, Charbonneau P, Delaugerre C, Suzan-Monti M, Loze B, Fonsart J, Peytavin G, Cheret A, Timsit J, Girard G, Lorente N, Préau M, Rooney JF, Wainberg MA, Thompson D,Rozenbaum W, Doré V, Marchand L, Simon MC, Etien N, Aboulker JP, Meyer L, Delfraissy JF; ANRS IPERGAY Study Group.

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Estimating Incidence of HIV Infection among Men Who Have Sex with Men, San Francisco, 2004-2014

After 30 years of the HIV epidemic in San Francisco there is hope that the number of new infections among men who have sex with men (MSM) is decreasing and that current novel interventions such as treatment as prevention and pre-exposure prophylaxis will hasten the year that the city sees the last of new HIV infections. In addition, new HIV cases/incidence is the key indicator to measure the trajectory of the HIV epidemic. In this analysis we present an alternate age-cohort approach to estimating HIV incidence and compare our results to other indicators of incidence. 

Data for the present analysis were collected through National HIV Behavioral Surveillance conducted among MSM in San Francisco using time location sampling from 2004 to 2014. We estimated HIV incidence using a model where a closed population of 100 was divided into number infected and uninfected according to the HIV prevalence of the 21-25 year group and then estimated what incidence over 30 years would result in the HIV prevalence at age 50+. Incidence estimates were 7 per 1000 person years (PY) (338 cases), 7 per 1000 PY (312), 6 per 1000 PY (285) and 6 per 1000 PY (271) for 2004, 2008, 2011 and 2014, respectively.

Our data suggest that recent declines in new HIV diagnoses among MSM in San Francisco maybe due to a reduction in a "back log" of undiagnosed cases and not as large of a decline in new cases or HIV incidence. We hypothesize that the decline in new HIV infections among MSM in San Francisco is much slower than suggested by the decline in new HIV diagnoses.

Purchase full article at: http://goo.gl/Meh4O6

By: Raymond HF1,2, Chen YH3, McFarland W4,3.

• 1University of California, San Francisco, Epidemiology and Biostatistics, San Francisco, USA. Hfisher.raymond@sfdph.org.
• 2San Francisco Department of Public Health, 25 Van Ness, Suite 500, San Francisco, CA, 94102, USA. Hfisher.raymond@sfdph.org.
• 3San Francisco Department of Public Health, 25 Van Ness, Suite 500, San Francisco, CA, 94102, USA.
• 4University of California, San Francisco, Epidemiology and Biostatistics, San Francisco, USA.  

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Estimating HIV Protective Effects of Method Adherence with Combinations of Preexposure Prophylaxis & Condom Use among African American Men Who Have Sex with Men

Prevention of sexually acquired HIV infection now includes both consistent condom use and daily use of oral antiretroviral preexposure prophylaxis (PrEP). Persons at substantial HIV risk can now use one or both prevention methods, but a combined HIV protective effect has not been assessed.

We use deterministic models to examine the impact of method adherence and rates of PrEP and male condom use on number of anticipated HIV infections. Analyses were based on hypothetical cohorts of 10,000 African American men who have sex with men (AAMSM), a population with the highest HIV incidence in the United States. Parameters used in the model (condom effectiveness, PrEP effectiveness, HIV incidence) were based on published findings.

Among AAMSM who never use PrEP, an estimated 323 annual HIV infections would occur among those who always use condoms, 1007 among sometimes condom users, and 1094 among never condoms users. Among AAMSM who never (or inconsistently) use condoms, 295 (272) infections would occur among those who report at least 90% PrEP adherence and 744 (684) infection occur with less than 50% adherence. Among AAMSM who are consistently (or sometimes) taking PrEP, the highest protection is seen with consistent condom use, 87 (220) HIV infections and 92.0% (79.9%) prevention effectiveness.

Among AAMSM with inconsistent or never condom use, the addition of PrEP at either modest or high adherence can increase HIV protection. For consistent condom users, any PrEP use can increase HIV protection. These analyses provide an approach for rethinking HIV risk management by calculating combined HIV protective effects of using one or more effective prevention methods.

Purchase full article at: http://goo.gl/6M04A7

By: Smith DK1, Herbst JH, Rose CE.

• 1From the Division of HIV/AIDS Prevention (DHAP), National Center for HIV/AIDS, Viral Hepatitis, STD, and TB Prevention (NCHHSTP), Centers for Disease Control and Prevention (CDC), Atlanta, GA.  

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Sexual Behavior Patterns and PrEP Dosing Preferences in a large sample of North American Men who have Sex with Men

Pre-exposure prophylaxis (PrEP), taken as a single daily co-formulated pill containing tenofovir-emtricitabine, is a promising intervention to reduce the likelihood of HIV acquisition in at-risk individuals, including men who have sex with men (MSM). Little is known about the acceptability of less than daily, intermittent PrEP (iPrEP) regimens. 

We conducted an online survey of North American MSM to characterize their sexual frequency and planning behaviors and correlate these with PrEP dosing preferences. Of the 3,217 respondents who completed the survey, 46% reported engaging in unplanned condomless anal intercourse (CAI) at least once in the prior 3 months and 8% reported engaging in CAI more than once per week. 

In multivariable analysis, reporting unplanned CAI was associated with lower educational level, identifying as homosexual/gay as compared to bisexual, being in a monogamous relationship, having a higher self-perceived risk of HIV acquisition, higher income, engaging in CAI more than five times in the last 3 months, and not having visited a healthcare provider in the previous year. 

Frequent CAI (>1x/week) was associated with being younger, 

• identifying as homosexual/gay as compared to bisexual, 
• being in a monogamous relationship, 
• and having a higher self-perceived risk of HIV. 

Having had only planned sex over the last 3 months was associated with a preference for event-based PrEP, while having frequent or unplanned CAI was associated with a preference for daily or time-driven PrEP regimens, respectively. 

Our findings suggest that preferences for different PrEP regimens are associated with the sexual frequency and planning behaviors of potential users.

Via:  http://ht.ly/SqMKb  Purchase full article at: http://goo.gl/vUU7H2

By: Stack C1, Oldenburg C, Mimiaga M, Elsesser SA, Krakower D, Novak DS, Egan J, Stall R, Safren S, Mayer KH.

• 11Department of Medicine, Beth Israel Deaconess Medical Center/Harvard Medical School, Boston, MA 2Department of Epidemiology, Harvard School of Public Health, Boston, MA 3Institute for Community Health Promotion, Brown University School of Public Health, Providence, RI 4The Fenway Institute, Fenway Health, Boston, MA 5Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, PA 6On-Line Buddies, Cambridge, MA 7Department of Behavioral and Community Health Sciences, University of Pittsburgh, Pittsburgh, PA 8Department of Psychology, University of Miami, Coral Gables, FL.