Original Article
Preexposure Chemoprophylaxis for HIV Prevention in Men Who Have Sex with Men
N Engl J Med 2010; 363:2587-2599December 30, 2010
Comments
open through January 4, 2011
- Abstract
Background
Antiretroviral chemoprophylaxis before exposure is a promising approach for the prevention of human immunodeficiency virus (HIV) acquisition.
Methods
We randomly assigned 2499 HIV-seronegative men or transgender women who have sex with men to receive a combination of two oral antiretroviral drugs, emtricitabine and tenofovir disoproxil fumarate (FTC–TDF), or placebo once daily. All subjects received HIV testing, risk-reduction counseling, condoms, and management of sexually transmitted infections.
Results
The study subjects were followed for 3324 person-years (median, 1.2 years; maximum, 2.8 years). Of these subjects, 10 were found to have been infected with HIV at enrollment, and 100 became infected during follow-up (36 in the FTC–TDF group and 64 in the placebo group), indicating a 44% reduction in the incidence of HIV (95% confidence interval, 15 to 63; P=0.005). In the FTC–TDF group, the study drug was detected in 22 of 43 of seronegative subjects (51%) and in 3 of 34 HIV-infected subjects (9%) (P<0.001). Nausea was reported more frequently during the first 4 weeks in the FTC–TDF group than in the placebo group (P<0.001). The two groups had similar rates of serious adverse events (P=0.57).
Conclusions
Oral FTC–TDF provided protection against the acquisition of HIV infection among the subjects. Detectable blood levels strongly correlated with the prophylactic effect. (Funded by the National Institutes of Health and the Bill and Melinda Gates Foundation; ClinicalTrials.gov number, NCT00458393.)
Media in This Article
Figure 1
Enrollment and Outcomes.Figure 2
Kaplan–Meier Estimates of Time to HIV Infection (Modified Intention-to-Treat Population).Article Activity
- Article
A total of 2.7 million new infections with the human immunodeficiency virus (HIV) were diagnosed worldwide in 2008, according to the Joint United Nations Program on HIV/AIDS (UNAIDS). Combination antiretroviral therapy for patients with HIV infection restores health and may decrease the transmission of the virus to uninfected partners.1 Therapy also decreases mother-to-child transmission.2
Postexposure chemoprophylaxis is recommended after occupational or nonoccupational exposure to HIV-infected fluids.3 The use of such chemoprophylaxis requires that people recognize when they might have been exposed to HIV and that they start therapy within 72 hours. Both challenges are substantial limitations to the use of postexposure chemoprophylaxis.4,5
We selected emtricitabine (FTC) and tenofovir disoproxil fumarate (TDF) combination therapy in a single tablet (FTC–TDF) for evaluation of preexposure prophylaxis because of several favorable characteristics.6 (Details are provided in the introduction in the Supplementary Appendix, available with the full text of this article at NEJM.org.) The protective activity of FTC and TDF has been shown in mice transplanted with human immune cells7 and in nonhuman primates.8-10– In these studies, there were increased levels of efficacy when both agents were used together, as compared with the use of either agent alone. The administration of the drug both before and after exposure was important for maximizing the protective benefit. 11
Daily preexposure prophylaxis with oral TDF had an acceptable side-effect profile in a trial involving West African women.12 A tenofovir 1% vaginal gel reduced HIV infection rates by 39% among women.13 Men and transgender women who have sex with men are disproportionately affected by the global epidemic.14,15 Surveys of such persons in the United States indicate that the current use of preexposure prophylaxis is rare, although the majority would consider such use if evidence of safety and efficacy became available.16,17
In this multinational study, called the Preexposure Prophylaxis Initiative (iPrEx) trial, we aimed to evaluate the safety and efficacy of once-daily oral FTC–TDF as compared with placebo for the prevention of HIV acquisition among men and transgender women who have sex with men.
Methods
Protocol Development
We developed the concept and protocol for this study using methods that came to be approved as “good participatory practices” by UNAIDS.18 The development of the protocol was sponsored by the National Institute of Health's Division of Acquired Immunodeficiency Syndrome (DAIDS). The protocol was approved by national government public health authorities in Peru, Ecuador, South Africa, Brazil, Thailand, and the United States and by the ethics committee at each site. All subjects provided written informed consent. The study coordinator vouches for the fidelity of the report to the protocol. The study protocol is available at NEJM.org, and a detailed description of the methods is provided in the Supplementary Appendix.
Study Population and Randomization
Inclusion criteria were male sex at birth, an age of 18 years or older, HIV-seronegative status, and evidence of high risk for acquisition of HIV infection. Subject codes were randomly assigned in blocks of 10, stratified according to site. The subject codes were assigned consecutively at the study sites to eligible subjects at the time of the first dispensation of a study drug. Serologic testing for hepatitis B was performed at screening.
Study Visits
Study visits were scheduled every 4 weeks after enrollment. Each 4-week visit included drug dispensation, pill count, adherence counseling, rapid testing for HIV antibodies, and taking of a medical history. Chemical and hematologic analyses were performed at weeks 4, 8, 12, 16, and 24 and every 12 weeks thereafter. During screening, a computer-assisted structured interview collected information about education level, self-identified sex, and alcohol use, along with subjects' perceived study-group assignment at week 12. High-risk behavior was assessed by interview every 12 weeks, and physical examinations and evaluations for sexually transmitted infections were performed at least every 24 weeks. Visits through May 1, 2010, are included in this report of the primary analysis of safety and efficacy. The visit cutoff date was set by the study sponsor without any access to interim findings and was intended to ensure observation of the targeted number of seroconversion events (85). The use of study drugs was intensively monitored and promoted (for details, see Methods in the Supplementary Appendix).
Standard Prevention Interventions
At every scheduled visit, subjects received a comprehensive package of prevention services, including HIV testing, risk-reduction counseling, condoms, and diagnosis and treatment of symptomatic sexually transmitted infections, including gonorrhea and chlamydia urethritis, syphilis, and herpes simplex virus type 2 (HSV-2). In addition, at 24-week intervals, subjects were screened for asymptomatic urethritis, syphilis, antibodies to HSV-2, and genital warts and ulcers; treatment was provided when indicated. Sexual partners were offered treatment of sexually transmitted infections that were diagnosed in the subject. Subjects were linked to local prevention and treatment services when required to receive standard-of-care services. All subjects were instructed to protect themselves from HIV with conventional methods, since they were unaware of their study-group assignment. Subjects who reported a recent unprotected exposure to an HIV-infected partner were referred for postexposure prophylaxis (at sites where such therapy was available), and the administration of a study drug was temporarily suspended. Vaccination against hepatitis B virus (HBV) was offered to all susceptible subjects.
Laboratory Testing
Testing for HIV antibody was performed on whole blood with the use of two different rapid tests at every scheduled visit, and reactive rapid tests were tested with the use of Western blot analysis of serum (Figure S1 in the Supplementary Appendix). Subjects with failed rapid tests were retested during the visit. HIV plasma RNA testing with the use of an assay with a lower limit of quantitation of 40 copies per milliliter was performed if seroconversion was detected within 12 weeks after enrollment. RNA testing was also used to identify the first date of laboratory evidence of infection for the as-treated analysis. Testing for drug-resistance genotyping and phenotyping was performed with the use of clinically validated assays on the basis of the viral load at the seroconversion visit.
Subgroup Analysis of Drug Levels
A prespecified subgroup analysis was performed to investigate whether drug levels correlated with protective effect. Subjects with HIV infection were matched with two control subjects, one from each study group who were selected from among seronegative subjects, according to study site (Figure S5 in the Supplementary Appendix). Plasma was tested for the presence of FTC and tenofovir (TFV), and peripheral-blood mononuclear cells were tested for FTC triphosphate (FTC-TP) and TFV diphosphate (TFV-DP), which are the active intracellular metabolites of FTC and TFV, respectively, with the use of validated liquid chromatography and tandem mass spectrometry assays.
Study Oversight
The study was designed by four of the investigators in collaboration with all the site investigators and communities. DAIDS reviewers approved the protocol, which was developed by the study investigators, and monitored the conduct of the trial at study sites. The Bill and Melinda Gates Foundation also provided funding but did not have a role in protocol development or site monitoring. Gilead Sciences donated both FTC–TDF and placebo tablets and provided travel-related support for meetings conducted by non-Gilead investigators. The role of Gilead Sciences in the development of the protocol was limited to sections regarding the handling of the study drugs. Neither Gilead Sciences nor any of its employees had a role in the accrual or analysis of the data or in the preparation of the manuscript. DAIDS agreed to give Gilead 30 days to comment on the manuscript, but there was no agreement to accept suggestions. The first author wrote the first draft of the manuscript (except for the drug-level sections, which were drafted by another investigator) and decided to submit the manuscript for publication. The protocol statistician and data manager vouch for the accuracy of the data, and the protocol chair and site investigators vouch for the completeness of the reported data.
Statistical Analysis
Data were collected on case-report forms and faxed to a DataFax server at DF/Net Research. It was determined that the observation of 85 incident HIV infections would yield a power of at least 80% with a one-sided alpha level of 0.05 to reject a null hypothesis of efficacy of 30% or less if the true efficacy were 60% or more. The modified intention-to-treat analysis included available data for all subjects except those with HIV RNA detected in their enrollment sample. The as-treated analysis used a time-dependent covariate indication as to whether the subject was known to fall below the prespecified level of study-drug compliance (50%) on any of the following: records of study-drug dispensation alone, pill-use calculation on the basis of study-drug dispensation and returns, and subjects' self-report. For the as-treated analysis, pills from unreturned bottles were assumed to have been taken, and late visits were included in the analysis if the last dispensation allowed pill use on 50% or more of days. Safety analyses included all subjects.
Results
Study Subjects
Of 4905 subjects who were screened, 2499 were enrolled in the study from July 10, 2007, through December 17, 2009, at 11 sites in six countries (Figure 1Figure 1
Enrollment and Outcomes.). The baseline characteristics of the two study groups were similar (Table 1Table 1
Baseline Characteristics of the Subjects.). All subjects were born male, although 29 (1%) reported their current gender identity as female. The ages of the subjects ranged from 18 to 67 years; the FTC–TDF group was on average 9 months older than the placebo group (mean age, 27.5 vs. 26.8 years; P=0.04).Among HBV-susceptible subjects at screening, 94% accepted HBV vaccination. We enrolled 13 subjects with chronic HBV infection that was detected at screening, and acute HBV infection was reported as an adverse event in 3 additional subjects (2 in the FTC–TDF group and 1 in the placebo group) after enrollment when elevated liver aminotransferase levels were observed. All the HBV infections resolved with detectable levels of immunity.
Follow-up and Adherence
The cohort was followed for 3324 person-years with a variable duration of observation (median, 1.2 years; maximum, 2.8 years) (Figure 1). There were no significant trends in visit completion rates over time. Most subjects said they did not know their study-group assignment at week 12, and those who guessed their assignment were evenly distributed between the two groups (Table S3 in the Supplementary Appendix). No subjects were told their study-group assignment during the course of the trial. A study drug was temporarily discontinued in 21 subjects (8 in the FTC–TDF group and 13 in the placebo group) so that they could receive postexposure prophylaxis for HIV (P=0.28).
The rate of self-reported pill use was lower in the FTC–TDF group than in the placebo group at week 4 (mean, 89% vs. 92%; P<0.001) and at week 8 (mean, 93% vs. 94%; P=0.006) but was similar thereafter (mean, 95% in the two groups). At each visit, a portion of subjects (approximately 6%) did not report the number of pills missed. The percentage of pill bottles returned was 66% by 30 days and 86% by 60 days. The rate of pill use that was estimated according to pill count also increased during the first 8 weeks and then remained stable at a median ranging from 89 to 95%, depending on whether pills from unreturned bottles were counted as having been taken or not taken. On the basis of pill-dispensation dates and quantities, the rate of pill use decreased during the first year, from 99% to 91%, a trend that contrasted with pill counts and self-report, which indicated an increased rate of use.
Sexual Practices
Sexual practices were similar in the two groups at all time points (P=0.97) (Figure S2 in the Supplementary Appendix). The total numbers of sexual partners with whom the respondent had receptive anal intercourse decreased, and the percentage of those partners who used a condom increased after subjects enrolled in the study. There were no significant between-group differences in the numbers of subjects with syphilis (P=0.49), gonorrhea (P=0.74), chlamydia (P=0.43), genital warts (P=0.53), or genital ulcers (P=0.62) during follow-up (Table S4 in the Supplementary Appendix).
Safety
In testing for elevations in serum creatinine levels, there were 41 instances of elevations that were at least 1.1 times the upper limit of the normal range or more than 1.5 times the baseline level. Of these elevations, 26 (2%) were in the FTC–TDF group and 15 (1%) were in the placebo group (P=0.08). Two of these elevations increased in grade, accounting for a total of 43 creatinine adverse events (Table 2Table 2
Adverse Events., and Table S9 in the Supplementary Appendix). Overall, 18 creatinine elevations (44%) remained in the normal range, and 36 (88%) were not confirmed on the next test. A total of 10 elevations led to discontinuation of a study drug (7 in the FTC–TDF group and 3 in the placebo group); study drugs were restarted in 9 subjects. Serum creatinine levels were elevated at more than one consecutive test in 5 subjects in the FTC–TDF group (<1%) and in none of the subjects in the placebo group. All elevations in the serum creatinine level resolved after the discontinuation of a study drug, within 4 weeks in 3 subjects, within 12 weeks in 1 subject, and within 20 weeks in 1 subject. Four of the subjects resumed taking FTC–TDF without recurrence of the elevation.Moderate nausea (grade 2 and above) was reported more frequently in the FTC–TDF group than in the placebo group (22 vs. 10 events, P=0.04), as was unintentional weight loss of 5% or more (34 vs. 19 events, P=0.04) (for details, see Table S10 in the Supplementary Appendix).
Effect of FTC–TDF on HIV Acquisition
HIV rapid testing was performed at 39,613 visits, during which there were false reactive tests for 3 subjects at 7 visits; each subject had multiple negative tests afterward. HIV seroconversion was observed in 110 persons, of whom 10 had plasma HIV RNA subsequently detected in specimens obtained at the enrollment visit. A finding of fewer than 40 copies per milliliter of plasma HIV RNA was documented for the other 100 HIV-infected subjects before seroconversion. Among the 100 subjects with emergent HIV infection, 36 occurred in the FTC–TDF group, and 64 occurred in the placebo group, representing a relative reduction of 44% in incidence in the modified intention-to-treat population (95% confidence interval [CI], 15 to 63; P=0.005) (Figure 2Figure 2
Kaplan–Meier Estimates of Time to HIV Infection (Modified Intention-to-Treat Population).). After adjustment for the difference in age between the two groups, the efficacy was 43% (95% CI, 14 to 62). The rate of pill use on 50% or more of days was recorded on the basis of pill counts, self-report, and dispensation records at 81% of visits on which efficacy was 50% (95% CI, 18 to 70; P=0.006). This rate did not differ significantly (P=0.48) from the efficacy at visits with less than 50% pill use of 32% (95% CI, −41 to 67%) (Figure 3Figure 3
HIV Incidence among Subjects Receiving FTC–TDF, According to Subgroup.). Efficacy of less than 30% could not be ruled out in the modified intention-to-treat analysis (P=0.15) or in the prespecified as-treated analysis at 50% pill use (P=0.09). There was no evidence of a change in HIV efficacy with longer follow-up (P=0.44).In prespecified analyses of efficacy according to subgroup, efficacy was higher among subjects who reported at screening that they had previously had unprotected receptive anal intercourse than among those who did not (efficacy, 58%; 95% CI, 32 to 74) (Figure 3). There was no significant between-group difference in protection on the basis of region, race or ethnic group, male circumcision, level of education, alcohol use, or age. In post hoc analyses, pill use on 90% or more of days was recorded at 49% of visits on which efficacy was 73% (95% CI, 41 to 88; P<0.001). Among all subjects, without exclusion for HIV infection at enrollment or the degree of compliance to the drug regimen, the efficacy was 47% (95% CI, 22 to 64; P=0.001).
Among the 10 subjects in whom plasma HIV RNA was subsequently detected in specimens obtained at enrollment, 5 had symptoms of an acute viral syndrome at enrollment, 2 had symptoms 1 week later (prompting an interim study visit), 1 had an anal sore, and 2 had leukopenia at enrollment. In these subjects, the clinicians did not suspect acute HIV infection, because the symptoms were attributed to an upper respiratory tract infection, sinusitis, or other non-HIV cause.
Of the preexisting HIV infections at enrollment, two occurred in the FTC–TDF group and eight in the placebo group (P=0.06). Among subjects who were infected after enrollment, the numbers with detectable plasma HIV RNA before seroconversion were 5 of 36 (14%) in the FTC–TDF group and 7 of 64 (11%) in the placebo group (P=0.75). The time to seroconversion after RNA detection was similar in the two groups (P=0.55). After the discontinuation of a study drug, seroconversion rates were similar among 320 subjects (161 in the FTC–TDF group and 159 in the placebo group) (P=0.42). These subjects had a total of 1173 visits for HIV testing after the discontinuation of a study drug (642 in the FTC–TDF group and 531 in the placebo group). During these visits, 5 seroconversions were observed (2 in the FTC–TDF group and 3 in the placebo group).
Drug-Level Detection and Prophylactic Effect
Among subjects who became infected with HIV, the median time between the tested specimen date and the last uninfected visit was 35 days (interquartile range, 28 to 56). No drug was detected in any plasma or cell specimens from subjects in the placebo group. Among subjects in the FTC–TDF group, at least one of the study-drug components was detected in 3 of 34 subjects with HIV infection (9%) and in 22 of 43 seronegative control subjects (51%) (Figure 4Figure 4
Levels of Study-Drug Components in Blood of Subjects Receiving FTC–TDF, According to HIV Status.). Of the 3 HIV-infected subjects with a detectable level of a study drug, none had cell-associated drug levels higher than the median for the 22 seronegative control subjects in whom a study-drug component was detected. Only 8% of subjects with HIV infection and 54% of control subjects who were considered “on treatment” on more than 50% of days had a detectable level of a study drug in plasma or peripheral-blood mononuclear cells (Table S8 in the Supplementary Appendix). Detection of the different drug components was more than 95% concordant (Table S6 in the Supplementary Appendix).In the FTC–TDF group, among subjects with a detectable study-drug level, as compared with those without a detectable level, the odds of HIV infection were lower by a factor of 12.9 (95% CI, 1.7 to 99.3; P<0.001), corresponding to a relative reduction in HIV risk of 92% (95% CI, 40 to 99; P<0.001). After adjustment for reported unprotected receptive anal intercourse, the relative risk reduction was 95% (95% CI, 70 to 99; P<0.001).
Effect of FTC–TDF on HIV Infection
Plasma HIV RNA levels and CD4+ T-cell counts were similar among subjects with seroconversion in the two groups (Figure S4 in the Supplementary Appendix). Among the 10 subjects who were infected at enrollment, 3 had FTC-resistant infections (2 of 2 in the FTC–TDF group and 1 of 8 in the placebo group) (Table S5 in the Supplementary Appendix). No TDF-resistant infections were observed. Among 36 subjects in the FTC–TDF group and 64 subjects in the placebo group who became infected with HIV during the trial, no FTC or TDF resistance was detected.
Discussion
Once-daily oral FTC–TDF provided 44% additional protection from HIV among men or transgender women who have sex with men who also received a comprehensive package of prevention services. The protective effect of FTC–TDF was significant but not as high as originally hypothesized during the design of the study. Although reported pill use was high, drug exposure that was measured objectively was substantially lower. The intracellular assay that was used in this study is expected to detect TFV-DP for 14 days or more after the last dose of TDF is taken (see Methods in the Supplementary Appendix). Other evidence of low drug exposure included the lack of drug resistance observed among emergent infections and the absence of suppression of the HIV RNA level in plasma at the seroconversion visit. There was no evidence of delayed seroconversion among subjects who were infected in the FTC–TDF group. More information will be available after the entire cohort stops receiving the study drug.
The estimate of biologic activity of FTC–TDF persists after adjustment for high-risk sexual practice, suggesting that the correlation between drug detection and protection is primarily due to the drug and not to other characteristics of subjects that may link poor adherence with higher risk. The testing of a larger number of specimens, from more subjects at more times, is needed to better define the minimum protective drug concentration. Protective drug levels may differ according to the type of exposure (rectal vs. penile). Drug level may have a role in monitoring trials, programs, and individual users. Methods for inexpensively measuring long-term drug exposure, such as that afforded by analysis of hair,19 would be helpful once such a method is fully validated.
Side effects may have contributed to low pill use among some subjects. As with treatment of HIV infection and the use of FTC–TDF in postexposure prophylaxis,20 the initiation of FTC–TDF preexposure prophylaxis was associated with self-limited start-up symptoms in a few subjects. The trial design involving a placebo may also have contributed to lower-than-expected pill use. All subjects were counseled that the study pill might be a placebo or an active drug having no proven benefit. Open-label research and program development could provide users with clearer information about expected benefits and risks, which might increase the use and efficacy of preexposure prophylaxis. Engagement with communities and additional behavioral research are needed to develop methods of counseling that better support such use.
The initiation of chemoprophylaxis either before or after exposure should be deferred in patients with signs or symptoms of a viral syndrome, which are often present during acute HIV infection.21,22 The initiation of postexposure prophylaxis in patients who are RNA-positive but antibody-negative has been linked with acquisition of resistance to FTC and lamivudine (3TC),5 as occurred in subjects in the FTC–TDF group who were already infected at enrollment in our trial. Ways to increase recognition of acute HIV infection would include routine measurement of body temperature and testing for HIV antibodies to evaluate viral syndromes, regardless of whether the presentation suggests HIV infection or another cause. Testing for HIV RNA at the time of the initiation of preexposure prophylaxis should be considered where available.
TDF treatment is known to cause decreases in renal function,23 and there were trends toward more creatinine elevations in the FTC–TDF group than in the placebo group. Most creatinine elevations were self-limited and were not confirmed on repeat testing of a new specimen, as might occur due to dehydration, creatine use, or exercise. The ability to detect safety outcomes, including drug resistance, may have been decreased by lower-than-expected drug exposure. In light of evidence of the efficacy of FTC–TDF, more information is needed about possible subclinical effects that may affect bone mineral density, low-level drug resistance, and proximal renal tubular function. Flares of hepatitis caused by HBV after stopping preexposure prophylaxis with TDF were not seen in West African women,12 but more information is needed. These issues are being investigated in existing trials of preexposure prophylaxis.
Reported high-risk behavior decreased substantially after enrollment and remained lower than at baseline during the trial. Safer behavior was also observed in a trial of preexposure prophylaxis with TDF in West African women12 and may reflect the services (e.g., counseling, testing, and dispensing of condoms) that are provided as part of such interventions. In addition, taking a pill a day may have served as a daily reminder of imminent risk and may have promoted planning for sex, which has been associated with lower HIV risk.24 Behavioral changes during future open-label use of preexposure prophylaxis may differ because of an increased expectation of benefits, although such “risk compensation” was not observed during an open-label study of postexposure prophylaxis, during which benefits were expected.25
The optimal regimen for preexposure prophylaxis has not been established, and data from the subjects in our study cannot be applied to other populations. Alternative regimens in different populations are being studied. (Details are available in the Discussion in the Supplementary Appendix and at www.avac.org.)
In our study, preexposure prophylaxis with oral FTC–TDF among men and transgender women who have sex with men addressed an important unmet need in public health. HIV prevalence is higher in this population than in other groups in almost all countries.14 In the United States, rates of HIV infection among such men and transgender women have climbed since the early 1990s, affecting in particular black and Hispanic subpopulations.26 Intensive counseling in behavioral risk reduction for such subjects has not been shown to be better than standard counseling.27 Although male circumcision partially protects heterosexual men,28-30 penile circumcision is not expected to protect those who are exposed on the rectal mucosa.31 Heterosexual women were partially protected by tenofovir 1% vaginal gel,13 but the safety and utility of tenofovir topical gels for rectal use is not yet known. In the FTC–TDF group, there was increased efficacy among subjects who reported having unprotected receptive anal intercourse, which is the main mode of HIV transmission among the subjects in our study and increases the risk of heterosexual women who engage in the practice.32 We showed that such subjects with a high risk of exposure to HIV can be mobilized to participate in prevention initiatives and that preexposure prophylaxis is effective for slowing the spread of HIV in this population.
Supported by the Division of Acquired Immunodeficiency Syndrome (DAIDS), National Institute of Allergy and Infectious Diseases, National Institutes of Health, as a cooperative agreement (UO1 AI64002, to Dr. Grant) and by the Bill and Melinda Gates Foundation. Study drugs were donated by Gilead Sciences. The pharmacological studies were sponsored by a cooperative agreement with DAIDS (UO1 AI84735, to Dr. Anderson). Support for some specimen handling came from a grant from DAIDS (RO1 AI062333, to Dr. Grant) and by the J. David Gladstone Institutes. Some infrastructure support at the University of California at San Francisco was provided by a grant from the National Institutes of Health (UL1 RR024131).
Disclosure forms provided by the authors are available with the full text of this article at NEJM.org.
This article (10.1056/NEJMoa1011205) was published on November 23, 2010, and updated on December 1, 2010, at NEJM.org.
Dr. Grant reports receiving support as an advisor to Siemens (the manufacturer of TruGene HIV-1 Genotyping Kit); Dr. Mayer reports receiving grant support from Gilead, Merck, and Bristol-Myers Squibb; Dr. Kallás reports serving on a data and safety monitoring board for Merck; Dr. Schechter reports receiving consulting fees and grants from Gilead; Drs. Liu and Anderson report receiving donations of study drug from Gilead for various PrEP projects; and Drs. Jaffe and Rooney report being employees of Gilead Sciences and owning stock in the company. No other potential conflict of interest relevant to this article was reported.
We thank the study subjects for their dedication to finding new ways to protect communities and for their trust in us; the community advisory boards; the members of the DAIDS multinational independent data and safety monitoring board, Kathy Edwards (chair), Shrikant I. Bangdiwala, KyungMann Kim, W.D. Francois Venter, Alejandro Llanos-Cuentas, Olavo Henrique Munhoz Leite, V.I. Mathan, Carlos Seas, Panpit Suwangool, Wafaa El-Sadr, Gary Maartens, Gabriel Thimonthe, Michael Proschan, and Dennis Dixon; community advocates Mitchell Warren, Julie Davids, Susana Chavez, Jorge (Tito) Bracamonte, and Carlos Caceres; Caitlin Fernandez, Joseph Rower, and Brandon Klein for their analytical pharmacology assistance; Grace Chow and Stephen Becker for their guidance as project officers; John Carroll of the Gladstone Institutes for providing original versions of the figures; Miguel Bernal and Ximena Barra for their print and film work; Mark Aurigemma for developing communication materials; Malu Robles for her assistance in the preparation of the manuscript; and Mark Wainberg, Mike Youle, Sandra Lehrman, Jose Pilotto, Neptali Arias, Vivian Levy, Kimberly Page, and Renee Ridzon for inspiration and logistical work.
Source Information
The authors' affiliations are listed in the Appendix.
Address reprint requests to Dr. Grant at the J. David Gladstone Institutes, University of California at San Francisco, 1650 Owens St., San Francisco, CA, 94158, or at robert.grant@ucsf.edu.
Other members of the Preexposure Prophylaxis Initiative (iPrEx) study team are listed in the Supplementary Appendix, available at NEJM.org.
Appendix
The authors' affiliations are as follows: the Gladstone Institute of Virology and Immunology (R.M.G., V.M., P.G., R.J.H., J.J.M., P.D., J.L.), the University of California, San Francisco (R.M.G., A.Y.L., S.P.B., K.M., F.W., D.V.G.), and the HIV Research Section, San Francisco Department of Public Health (A.Y.L., S.P.B.) — all in San Francisco; Investigaciones Medicas en Salud, Lima (J.R.L., L.V.), Asociación Civil Impacta Salud y Educación, Lima (J.R.L., J.V.G.-C., M.E.R.-C., C.G.), and Asociación Civil Selva Amazónica, Iquitos (M.C.) — all in Peru; the University of Colorado, Denver (P.L.A., L.R.B., J.-H.Z.).; Fundación Ecuatoriana Equidad, Guayaquil, Ecuador (O.M.-H., T.F.); Instituto de Pesquisa Clinica Evandro Chagas–Fundação Oswaldo Cruz (V.G.V.), and Projeto Praça Onze, Hospital Escola São Francisco de Assis, Universidade Federal do Rio de Janeiro (M.S.) — both in Rio de Janeiro; Brown University, Providence, RI (K.H.M.); the Fenway Institute, Fenway Health, Boston (K.H.M.); the Division of Clinical Immunology and Allergy, School of Medicine, University of São Paulo, and Instituto de Investigação em Imunologia — both in São Paulo (E.G.K.); Research Institute for Health Sciences, Chiang Mai University, Chiang Mai, Thailand (S.C.); Desmond Tutu HIV Centre and Department of Medicine, University of Cape Town, Cape Town, South Africa (L.-G.B.); Division of AIDS, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD (A.I.M., D.N.B.); Gilead Sciences, Foster City, CA ( J.F.R., H.S.J.); DF/Net Research, Seattle (B.P.); Applied Health Research, Brighton, MI (K.R.A.); and the Center for Health, Intervention, and Prevention, University of Connecticut, Storrs (K.R.A.).
- References
References
1
Donnell D ,Baeten JM ,Kiarie J , et al. Heterosexual HIV-1 transmission after initiation of antiretroviral therapy: a prospective cohort analysis. Lancet 2010;375:2092-2098
CrossRef | Web of Science | Medline2
Connor EM ,Sperling RS ,Gelber R , et al. Reduction of maternal-infant transmission of human immunodeficiency virus type 1 with zidovudine treatment. N Engl J Med 1994;331:1173-1180
Full Text | Web of Science | Medline3
Smith DK ,Grohskopf LA ,Black RJ , et al. Antiretroviral postexposure prophylaxis after sexual, injection-drug use, or other nonoccupational exposure to HIV in the United States: recommendations from the U.S. Department of Health and Human Services. MMWR Recomm Rep 2005;54:1-20
Medline4
Schechter M ,do Lago RF ,Mendelsohn AB ,Moreira RI ,Moulton LH ,Harrison LH . Behavioral impact, acceptability, and HIV incidence among homosexual men with access to postexposure chemoprophylaxis for HIV. J Acquir Immune Defic Syndr 2004;35:519-525
CrossRef | Web of Science | Medline5
Roland ME ,Neilands TB ,Krone MR , et al. Seroconversion following nonoccupational postexposure prophylaxis against HIV. Clin Infect Dis 2005;41:1507-1513
CrossRef | Web of Science | Medline6
Grant RM ,Buchbinder S ,Cates W Jr , et al. AIDS: promote HIV chemoprophylaxis research, don't prevent it. Science 2005;309:2170-2171
CrossRef | Web of Science | Medline7
Denton PW ,Estes JD ,Sun Z , et al. Antiretroviral pre-exposure prophylaxis prevents vaginal transmission of HIV-1 in humanized BLT mice. PLoS Med 2008;5:e16-e16
CrossRef | Web of Science | Medline8
Tsai C-C ,Follis KE ,Sabo A , et al. Prevention of SIV infection in macaques by (R)-9-(2-phosphonylmethoxypropyl)adenine. Science 1995;270:1197-1199
CrossRef | Web of Science | Medline9
Van Rompay KKA ,McChesney MB ,Aguirre NL ,Schmidt KA ,Bischofberger N ,Marthas ML . Two low doses of tenofovir protect newborn macaques against oral simian immunodeficiency virus infection. J Infect Dis 2001;184:429-438
CrossRef | Web of Science | Medline10
Garcia-Lerma JG ,Otten RA ,Qari SH , et al. Prevention of rectal SHIV transmission in macaques by daily or intermittent prophylaxis with emtricitabine and tenofovir. PLoS Med 2008;5:e28-e28
CrossRef | Web of Science | Medline11
Garcia-Lerma JG ,Cong ME ,Mitchell J , et al. Intermittent prophylaxis with oral Truvada protects macaques from rectal SHIV infection. Sci Transl Med 2010;2:14ra4-14ra4
CrossRef | Web of Science12
Peterson L ,Taylor D ,Roddy R , et al. Tenofovir disoproxil fumarate for prevention of HIV infection in women: a phase 2, double-blind, randomized, placebo-controlled trial. PLoS Clin Trials 2007;2:e27-e27
CrossRef | Medline13
Abdool Karim Q ,Abdool Karim SS ,Frohlich JA , et al. Effectiveness and safety of tenofovir gel, an antiretroviral microbicide, for the prevention of HIV infection in women. Science 2010;329:1168-1174
CrossRef | Web of Science | Medline14
van Griensven F , de Lind van Wijngaarden JW,Baral S ,Grulich A . The global epidemic of HIV infection among men who have sex with men. Curr Opin HIV AIDS 2009;4:300-307
CrossRef | Web of Science15
Beyrer C ,Baral SD ,Walker D ,Wirtz AL ,Johns B ,Sifakis F . The expanding epidemics of HIV type 1 among men who have sex with men in low- and middle-income countries: diversity and consistency. Epidemiol Rev 2010;32:137-151
CrossRef | Web of Science | Medline16
Liu AY ,Kittredge PV ,Vittinghoff E , et al. Limited knowledge and use of HIV post- and pre-exposure prophylaxis among gay and bisexual men. J Acquir Immune Defic Syndr 2008;47:241-247
CrossRef | Web of Science | Medline17
Mimiaga MJ ,Case P ,Johnson CV ,Safren SA ,Mayer KH . Preexposure antiretroviral prophylaxis attitudes in high-risk Boston area men who report having sex with men: limited knowledge and experience but potential for increased utilization after education. J Acquir Immune Defic Syndr 2009;50:77-83
CrossRef | Web of Science | Medline18
Good participatory practice: guidelines for biomedical HIV prevention trials. Geneva: UNAIDS, 2007.
19
Liu A, Vittinghoff E, Gandhi M, et al. Validating measures of tenofovir drug exposure in a US pre-exposure prophylaxis trial. In: Program and abstracts of the 17th Conference on Retroviruses and Opportunistic Infections, San Francisco, February 27–March 2, 2010.
20
Mayer KH ,Mimiaga MJ ,Cohen D , et al. Tenofovir DF plus lamivudine or emtricitabine for nonoccupational postexposure prophylaxis (NPEP) in a Boston community health center. J Acquir Immune Defic Syndr 2008;47:494-499
CrossRef | Web of Science | Medline21
Schacker TW ,Hughes JP ,Shea T ,Coombs RW ,Corey L . Biological and virologic characteristics of primary HIV infection. Ann Intern Med 1998;128:613-620
Web of Science | Medline22
Hofer CB ,Harrison LH ,Struchiner CJ , et al. Acute retrovirus syndrome among prospectively identified homosexual men with incident HIV infection in Brazil. J Acquir Immune Defic Syndr 2000;25:188-191
CrossRef | Web of Science | Medline23
Gallant JE ,Winston JA ,DeJesus E , et al. The 3-year renal safety of a tenofovir disoproxil fumarate vs. a thymidine analogue-containing regimen in antiretroviral-naive patients. AIDS 2008;22:2155-2163
CrossRef | Web of Science | Medline24
van Griensven F ,Thienkrua W ,Sukwicha W , et al. Sex frequency and sex planning among men who have sex with men in Bangkok, Thailand: implications for pre- and post-exposure prophylaxis against HIV infection. J Int AIDS Soc 2010;13:13-13
CrossRef | Web of Science25
Martin JN ,Roland ME ,Neilands TB , et al. Use of postexposure prophylaxis against HIV infection following sexual exposure does not lead to increases in high-risk behavior. AIDS 2004;18:787-792
CrossRef | Web of Science | Medline26
Hall HI ,Song R ,Rhodes P , et al. Estimation of HIV incidence in the United States. JAMA 2008;300:520-529
CrossRef | Web of Science | Medline27
Koblin B ,Chesney M ,Coates T . Effects of a behavioural intervention to reduce acquisition of HIV infection among men who have sex with men: the EXPLORE randomised controlled study. Lancet 2004;364:41-50
CrossRef | Web of Science | Medline28
Auvert B ,Taljaard D ,Lagarde E ,Sobngwi-Tambekou J ,Sitta R ,Puren A . Randomized, controlled intervention trial of male circumcision for reduction of HIV infection risk: the ANRS 1265 Trial. PLoS Med 2005;2:e298-e298[Erratum, PLoS Med 2006;3(5):e226.]
CrossRef | Web of Science | Medline29
Bailey RC ,Moses S ,Parker CB , et al. Male circumcision for HIV prevention in young men in Kisumu, Kenya: a randomised controlled trial. Lancet 2007;369:643-656
CrossRef | Web of Science | Medline30
Gray RH ,Kigozi G ,Serwadda D , et al. Male circumcision for HIV prevention in men in Rakai, Uganda: a randomised trial. Lancet 2007;369:657-666
CrossRef | Web of Science | Medline31
Templeton DJ ,Millett GA ,Grulich AE . Male circumcision to reduce the risk of HIV and sexually transmitted infections among men who have sex with men. Curr Opin Infect Dis 2010;23:45-52
CrossRef | Web of Science | Medline32
Baggaley RF ,White RG ,Boily MC . HIV transmission risk through anal intercourse: systematic review, meta-analysis and implications for HIV prevention. Int J Epidemiol 2010;39:1048-1063
CrossRef | Web of Science | Medline
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1
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CrossRef2
S.M. Owen. (2012) Testing for acute HIV infection. Current Opinion in HIV and AIDS 7:2, 125-130
CrossRef3
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CrossRef4
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CrossRef5
, Douglas Bruce, Gary W. Harper, Katie Suleta. (2012) Sexual Risk Behavior and Risk Reduction Beliefs Among HIV-Positive Young Men Who have Sex with Men. AIDS and Behavior
CrossRef6
Ramesh S. Paranjape, Madhuri R. Thakar, Manisha V. Ghate, Sheela V. Godbole. (2012) Current Status of Research on HIV Epidemic, Pathogenesis, Management and Prevention in India. Proceedings of the National Academy of Sciences, India Section B: Biological Sciences
CrossRef7
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CrossRef8
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CrossRef9
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CrossRef10
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CrossRef11
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CrossRef12
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CrossRef13
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CrossRef14
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CrossRef15
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CrossRef16
Nelson L. Michael. (2012) Rare serotype adenoviral vectors for HIV vaccine development. Journal of Clinical Investigation 122:1, 25-27
CrossRef17
L. Mandelbrot. (2012) Désir d’enfant et VIH : le préservatif est-il dépassé ?. Gynécologie Obstétrique & Fertilité 40:1, 58-61
CrossRef18
Deborah Cohan, Shannon Weber, Ronald Goldschmidt. (2012) Safer conception options for HIV-serodiscordant couples. American Journal of Obstetrics and Gynecology 206:1, e21
CrossRef19
Justin J. O’Hagan, Miguel A. Hernán, Rochelle P. Walensky, Marc Lipsitch. (2012) Apparent declining efficacy in randomized trials. AIDS 26:2, 123-126
CrossRef20
Koen K.A. Van Rompay. (2012) The Use of Nonhuman Primate Models of HIV Infection for the Evaluation of Antiviral Strategies. AIDS Research and Human Retroviruses 28:1, 16-35
CrossRef21
Thomas J. Ketas, Sophie Holuigue, Katie Matthews, John P. Moore, Per Johan Klasse. (2012) Env-glycoprotein heterogeneity as a source of apparent synergy and enhanced cooperativity in inhibition of HIV-1 infection by neutralizing antibodies and entry inhibitors. Virology 422:1, 22-36
CrossRef22
Mark W Hull, Julio SG Montaner. (2012) Oral antiretroviral therapy for the prevention of HIV-1 infection: ready for prime time?. Clinical Investigation 2:1, 1-4
CrossRef23
D Dolling, AN Phillips, V Delpech, D Pillay, PA Cane, AM Crook, J Shepherd, E Fearnhill, T Hill, D Dunn, . (2012) Evaluating the extent of potential resistance to pre-exposure prophylaxis within the UK HIV-1-infectious population of men who have sex with men. HIV Medicinen/a-n/a
CrossRef24
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CrossRef25
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CrossRef26
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CrossRef27
J. D. Shelton. (2011) ARVs as HIV Prevention: A Tough Road to Wide Impact. Science 334:6063, 1645-1646
CrossRef28
C. B. Hurt, J. J. Eron, M. S. Cohen. (2011) Pre-Exposure Prophylaxis and Antiretroviral Resistance: HIV Prevention at a Cost?. Clinical Infectious Diseases 53:12, 1265-1270
CrossRef29
J. M. Marrazzo, W. Cates. (2011) Interventions to Prevent Sexually Transmitted Infections, Including HIV Infection. Clinical Infectious Diseases 53:suppl 3, S64-S78
CrossRef30
K. B. Patterson, H. A. Prince, E. Kraft, A. J. Jenkins, N. J. Shaheen, J. F. Rooney, M. S. Cohen, A. D. M. Kashuba. (2011) Penetration of Tenofovir and Emtricitabine in Mucosal Tissues: Implications for Prevention of HIV-1 Transmission. Science Translational Medicine 3:112, 112re4-112re4
CrossRef31
Ronald A. Brooks, Raphael J. Landovitz, Rachel L. Kaplan, Eli Lieber, Sung-Jae Lee, Thomas W. Barkley. (2011) Sexual Risk Behaviors and Acceptability of HIV Pre-exposure Prophylaxis Among HIV-Negative Gay and Bisexual Men in Serodiscordant Relationships: A Mixed Methods Study. AIDS Patient Care and STDs111207094037003
CrossRef32
Iryna B. Zablotska, Garrett Prestage, Martin Holt, Mary Poynten, John de Wit, Rebecca Guy, Limin Mao, John McAllister, Andrew E. Grulich. (2011) Australian Gay Men Who Have Taken Nonoccupational Postexposure Prophylaxis for HIV Are in Need of Effective HIV Prevention Methods. JAIDS Journal of Acquired Immune Deficiency Syndromes 58:4, 424-428
CrossRef33
B. E. Nichols, C. A. B. Boucher, D. A. M. C. van de Vijver. (2011) HIV testing and antiretroviral treatment strategies for prevention of HIV infection: impact on antiretroviral drug resistance. Journal of Internal Medicine 270:6, 532-549
CrossRef34
Yelina Alvarez, Michael Tuen, Arthur Nàdas, Catarina E. Hioe. (2011) In Vitro Restoration of Th17 Response During HIV Infection with an Antiretroviral Drug and Th17 Differentiation Cytokines. AIDS Research and Human Retroviruses111201130717009
CrossRef35
Stefano Rusconi. (2011) Investigators Involvement in the Care of HIV-Infected Individuals. JAIDS Journal of Acquired Immune Deficiency Syndromes 58:4, e118-e119
CrossRef36
Lindsay M Ferguson, Lisa Cencia Rohan. (2011) The importance of the vaginal delivery route for antiretrovirals in HIV prevention. Therapeutic Delivery 2:12, 1535-1550
CrossRef37
Nirupama Deshmane Sista, Quarraisha Abdool Karim, Kathy Hinson, Deborah Donnell, Susan H Eshleman, Sten H Vermund. (2011) Experience in international clinical research: the HIV Prevention Trials Network. Clinical Investigation 1:12, 1609-1618
CrossRef38
Salim S Abdool Karim, Quarraisha Abdool Karim. (2011) Antiretroviral prophylaxis: a defining moment in HIV control. The Lancet 378:9809, e23-e25
CrossRef39
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CrossRef40
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CrossRef41
Thomas C. Quinn. (2011) The 30-Year War on AIDS: Have We Reached the Tipping Point?. Sexually Transmitted Diseases 38:12, 1089-1093
CrossRef42
Angela DM Kashuba, Kristine B Patterson, Julie B Dumond, Myron S Cohen. (2011) Pre-exposure prophylaxis for HIV prevention: how to predict success. The Lancet
CrossRef43
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CrossRef44
Douglas Krakower, Kenneth H. Mayer. (2011) Promising Prevention Approaches: Tenofovir Gel and Prophylactic Use of Antiretroviral Medications. Current HIV/AIDS Reports 8:4, 241-248
CrossRef45
James A. McIntyre. (2011) Can Devices for Adult Male Circumcision Help Bridge the Implementation Gap for HIV Prevention Services?. JAIDS Journal of Acquired Immune Deficiency Syndromes 58:5, 506-508
CrossRef46
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CrossRef47
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CrossRef48
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CrossRef49
Roger Detels, Dean L. Winslow. (2011) Treatment as Prevention. AIDS1
CrossRef50
Lisa M. McDaid, Graham J. Hart. (2011) Willingness to Participate in Future HIV Prevention Studies Among Gay and Bisexual Men in Scotland, UK: A Challenge for Intervention Trials. AIDS and Behavior
CrossRef51
Stefan Baral, Frangiscos Sifakis, Alena Peryskina, Vladimir Mogilnii, Nicole F. Masenior, Boris Sergeyev, Irina Deobald, Andrea L. Wirtz, Chris Beyrer. (2011) Risks for HIV Infection Among Gay, Bisexual, and Other Men Who Have Sex with Men in Moscow and St. Petersburg, Russia. AIDS Research and Human Retroviruses111116070158006
CrossRef52
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CrossRef53
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CrossRef54
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CrossRef55
Beryl A. Koblin, Gordon Mansergh, Victoria Frye, Hong Van. Tieu, Donald R. Hoover, Sebastian Bonner, Stephen A. Flores, Sharon M. Hudson, Grant N. Colfax. (2011) Condom-Use Decision Making in the Context of Hypothetical Pre-Exposure Prophylaxis Efficacy Among Substance-Using Men Who Have Sex With Men. JAIDS Journal of Acquired Immune Deficiency Syndromes 58:3, 319-327
CrossRef56
Samuel B. Keller, Davey M. Smith. (2011) The price of tenofovir-emtricitabine undermines the cost-effectiveness and advancement of pre-exposure prophylaxis. AIDS 25:18, 2308-2310
CrossRef57
S. Daou, A. Calmy. (2011) Le traitement prophylactique de l’infection par le virus de l’immunodéficience humaine (VIH). La Revue de Médecine Interne 32:11, 658-662
CrossRef58
Lauren L. Katzen, José A. Fernández-Romero, Avina Sarna, Kailapuri G. Murugavel, Daniel Gawarecki, Thomas M. Zydowsky, Barbara S. Mensch. (2011) Validation of a Dye Stain Assay for Vaginally Inserted Hydroxyethylcellulose-Filled Microbicide Applicators. Sexually Transmitted Diseases 38:11, 1050-1055
CrossRef59
John Stover. (2011) 30 years after HIV identification: where to from here?. Expert Review of Anti-infective Therapy 9:11, 947-949
CrossRef60
P. Volberding. (2011) The impact of HIV research on health outcome and healthcare policy. Annals of Oncology 22:Suppl 7, vii50-vii53
CrossRef61
A. J. Leigh Brown, S. J. Lycett, L. Weinert, G. J. Hughes, E. Fearnhill, D. T. Dunn, . (2011) Transmission Network Parameters Estimated From HIV Sequences for a Nationwide Epidemic. Journal of Infectious Diseases 204:9, 1463-1469
CrossRef62
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CrossRef63
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CrossRef64
Pietro L. Vernazza, Irma Graf, Ulrike Sonnenberg-Schwan, Maria Geit, Anja Meurer. (2011) Preexposure prophylaxis and timed intercourse for HIV-discordant couples willing to conceive a child. AIDS 25:16, 2005-2008
CrossRef65
Harkaitz Azkune, Maialen Ibarguren, Xabier Camino, José Antonio Iribarren. (2011) Prevención de la transmisión del VIH (vertical, ocupacional y no ocupacional). Enfermedades Infecciosas y Microbiología Clínica 29:8, 615-625
CrossRef66
José Vicente Fernández-Montero, Vicente Soriano. (2011) Profilaxis preexposición en la prevención de la infección por virus de la inmunodeficiencia humana. Medicina Clínica 137:10, 446-448
CrossRef67
Robert T Koppenhaver, Stephen W Sorensen, Paul G Farnham, Stephanie L Sansom. (2011) The Cost-Effectiveness of Pre-Exposure Prophylaxis in Men Who Have Sex With Men in the United States: An Epidemic Model. JAIDS Journal of Acquired Immune Deficiency Syndromes 58:2, e51-e52
CrossRef68
Felipe García, Juan Carlos López Bernaldo de Quirós, Carmen E. Gómez, Beatriz Perdiguero, Jose L. Nájera, Victoria Jiménez, Juan García-Arriaza, Alberto C. Guardo, Iñaki Pérez, Vicens Díaz-Brito, Matilde Sánchez Conde, Nuria González, Amparo Alvarez, José Alcamí, José Luis Jiménez, Judit Pich, Joan Albert Arnaiz, María J. Maleno, Agathe León, María Angeles Muñoz-Fernández, Peter Liljeström, Jonathan Weber, Giuseppe Pantaleo, José M. Gatell, Montserrat Plana, Mariano Esteban. (2011) Safety and immunogenicity of a modified pox vector-based HIV/AIDS vaccine candidate expressing Env, Gag, Pol and Nef proteins of HIV-1 subtype B (MVA-B) in healthy HIV-1-uninfected volunteers: A phase I clinical trial (RISVAC02). Vaccine 29:46, 8309-8316
CrossRef69
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CrossRef70
Rewa Kohli, Sharon Tsui, Sanjay Mehendale, Elizabeth Tolley. (2011) Indian married men's interest in microbicide use. AIDS Care 23:10, 1344-1349
CrossRef71
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CrossRef72
Janni J. Kinsler, William E. Cunningham, César R. Nureña, Carsten Nadjat-Haiem, Beatriz Grinsztejn, Martin Casapia, Orlando Montoya-Herrera, Jorge Sánchez, Jerome T. Galea. (2011) Using Conjoint Analysis to Measure the Acceptability of Rectal Microbicides Among Men Who Have Sex with Men in Four South American Cities. AIDS and Behavior
CrossRef73
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CrossRef74
Vitaly A. Kushnir, William Lewis. (2011) Human immunodeficiency virus/acquired immunodeficiency syndrome and infertility: emerging problems in the era of highly active antiretrovirals. Fertility and Sterility 96:3, 546-553
CrossRef75
Leolin Katsidzira, James G. Hakim. (2011) HIV prevention in southern Africa: why we must reassess our strategies?. Tropical Medicine & International Health 16:9, 1120-1130
CrossRef76
Lane R. Bushman, Jennifer J. Kiser, Joseph E. Rower, Brandon Klein, Jia-Hua Zheng, Michelle L. Ray, Peter L. Anderson. (2011) Determination of nucleoside analog mono-, di-, and tri-phosphates in cellular matrix by solid phase extraction and ultra-sensitive LC–MS/MS detection. Journal of Pharmaceutical and Biomedical Analysis 56:2, 390-401
CrossRef77
Nicole Stolte-Leeb, Roberta Loddo, Sophia Antimisiaris, Tina Schultheiss, Ulrike Sauermann, Monika Franz, Spyridon Mourtas, Christophe Parsy, Richard Storer, Paolo La Colla, Christiane Stahl-Hennig. (2011) Topical Nonnucleoside Reverse Transcriptase Inhibitor MC 1220 Partially Prevents Vaginal RT-SHIV Infection of Macaques. AIDS Research and Human Retroviruses 27:9, 933-943
CrossRef78
S. A. Springer, A. C. Spaulding, J. P. Meyer, F. L. Altice. (2011) Public Health Implications for Adequate Transitional Care for HIV-Infected Prisoners: Five Essential Components. Clinical Infectious Diseases 53:5, 469-479
CrossRef79
Hammer, Scott M., . (2011) Antiretroviral Treatment as Prevention. New England Journal of Medicine 365:6, 561-562
Full Text80
Andrew Anglemyer, George W Rutherford, Rachel C Baggaley, Matthias Egger, Nandi Siegfried, George W Rutherford. 2011. Antiretroviral therapy for prevention of HIV transmission in HIV-discordant couples. .
CrossRef81
Richard T. Gray, Mohammad H. Ghaus, Alexander Hoare, David P. Wilson. (2011) Expected epidemiological impact of the introduction of a partially effective HIV vaccine among men who have sex with men in Australia. Vaccine 29:36, 6125-6129
CrossRef82
Kelly A Curtis, M Susan Kennedy, Amara Luckay, Mian-er Cong, Ae S Youngpairoj, Qi Zheng, James Smith, Debra Hanson, Walid Heneine, S Michele Owen, J Gerardo García-Lerma. (2011) Delayed Maturation of Antibody Avidity but Not Seroconversion in Rhesus Macaques Infected With Simian HIV During Oral Pre-Exposure Prophylaxis. JAIDS Journal of Acquired Immune Deficiency Syndromes 57:5, 355-362
CrossRef83
Gita Ramjee. (2011) Antiretroviral-based microbicides and oral pre-exposure prophylaxis for HIV prevention. Future Virology 6:8, 997-1014
CrossRef84
Marc P. Girard, Saladin Osmanov, Olga M. Assossou, Marie-Paule Kieny. (2011) Human immunodeficiency virus (HIV) immunopathogenesis and vaccine development: A review. Vaccine 29:37, 6191-6218
CrossRef85
Kevin M De Cock, Wafaa M El-Sadr, Tedros A Ghebreyesus. (2011) Game Changers: Why Did the Scale-Up of HIV Treatment Work Despite Weak Health Systems?. JAIDS Journal of Acquired Immune Deficiency Syndromes 57, S61-S63
CrossRef86
Sten H Vermund. (2011) Modeling interventions to assess HIV epidemic impact in Africa. JAIDS Journal of Acquired Immune Deficiency Syndromes1
CrossRef87
Paula M. Frew, Matthew Archibald, Brooke Hixson, Carlos del Rio. (2011) Socioecological influences on community involvement in HIV vaccine research. Vaccine 29:36, 6136-6143
CrossRef88
Kyeen M. Andersson, John Stover. (2011) The potential impact of a moderately effective HIV vaccine with rapidly waning protection in South Africa and Thailand. Vaccine 29:36, 6092-6099
CrossRef89
Nico J.D. Nagelkerke, Jan A.C. Hontelez, Sake J. de Vlas. (2011) The potential impact of an HIV vaccine with limited protection on HIV incidence in Thailand: A modeling study. Vaccine 29:36, 6079-6085
CrossRef90
AR Giuliano, MF Schim van der Loeff, AG Nyitray. (2011) Circumcised HIV-infected men and HPV transmission. The Lancet Infectious Diseases 11:8, 581-582
CrossRef91
Reinhard H. Dennin, Michael Lafrenz, Arndt Sinn, Lan-juan Li. (2011) Dilemma of concepts and strategies for the prevention of spread of HIV in relation to human behavior, law and human rights. Journal of Zhejiang University SCIENCE B 12:7, 591-610
CrossRef92
Louise Kuhn, Ida Susser, Zena Stein. (2011) Can further placebo-controlled trials of antiretroviral drugs to prevent sexual transmission of HIV be justified?. The Lancet 378:9787, 285-287
CrossRef93
John Imrie, Frank Tanser. (2011) Targeting strategies and behavior change to combat the HIV epidemic in southern Africa. Future Virology 6:7, 793-800
CrossRef94
Kenneth H Mayer. (2011) Antiretrovirals for HIV prevention: translating promise into praxis. The Lancet 378:9787, 206-208
CrossRef95
Laurent Bélec, Mohammad-Ali Jenabian, Charlotte Charpentier, Hela Saïdi. (2011) Combinatorial prevention of HIV transmission in women: the case for a vaginal microbicide. Future Microbiology 6:7, 731-737
CrossRef96
Nancy S Padian, Sandra I McCoy, Salim S Abdool Karim, Nina Hasen, Julia Kim, Michael Bartos, Elly Katabira, Stefano M Bertozzi, Bernhard Schwartländer, Myron S Cohen. (2011) HIV prevention transformed: the new prevention research agenda. The Lancet 378:9787, 269-278
CrossRef97
Erik De Clercq. (2011) The clinical potential of the acyclic (and cyclic) nucleoside phosphonates. The magic of the phosphonate bond. Biochemical Pharmacology 82:2, 99-109
CrossRef98
Merlin Robb. (2011) HIV vaccine development: a new beginning. Expert Review of Vaccines 10:7, 925-927
CrossRef99
Sheldon R Morris, Susan J Little. (2011) MSM: resurgent epidemics. Current Opinion in HIV and AIDS 6:4, 326-332
CrossRef100
Salim S Abdool Karim, Angela DM Kashuba, Lise Werner, Quarraisha Abdool Karim. (2011) Drug concentrations after topical and oral antiretroviral pre-exposure prophylaxis: implications for HIV prevention in women. The Lancet 378:9787, 279-281
CrossRef101
R. J. Shattock, M. Warren, S. McCormack, C. A. Hankins. (2011) Turning the Tide Against HIV. Science 333:6038, 42-43
CrossRef102
(2011) A big disease with a little name. Nature 474:7349, 5-5
CrossRef103
Salim S. Abdool Karim. (2011) Stigma impedes AIDS prevention. Nature 474:7349, 29-31
CrossRef104
Meredith R. Clark, Patrick F. Kiser, Andrew Loxley, Christopher McConville, R. Karl Malcolm, David R. Friend. (2011) Pharmacokinetics of UC781-loaded intravaginal ring segments in rabbits: a comparison of polymer matrices. Drug Delivery and Translational Research 1:3, 238-246
CrossRef105
Kumi Smith, Kimberly A Powers, Angela DM Kashuba, Myron S Cohen. (2011) HIV-1 treatment as prevention: the good, the bad, and the challenges. Current Opinion in HIV and AIDS1
CrossRef106
Theodoros Kelesidis, Raphael J. Landovitz. (2011) Preexposure Prophylaxis for HIV Prevention. Current HIV/AIDS Reports 8:2, 94-103
CrossRef107
Natasha A. Verma, Anna C. Lee, Betsy C. Herold, Marla J. Keller. (2011) Topical Prophylaxis for HIV Prevention in Women: Becoming a Reality. Current HIV/AIDS Reports 8:2, 104-113
CrossRef108
Arleen A. Leibowitz, Karen Byrnes Parker, Mary Jane Rotheram-Borus. (2011) A US Policy Perspective on Oral Preexposure Prophylaxis for HIV. American Journal of Public Health 101:6, 982-985
CrossRef109
Y. Omar Whiteside, Tammy Harris, Christopher Scanlon, Stephen Clarkson, Wayne Duffus. (2011) Self-Perceived Risk of HIV Infection and Attitudes About Preexposure Prophylaxis Among Sexually Transmitted Disease Clinic Attendees in South Carolina. AIDS Patient Care and STDs 25:6, 365-370
CrossRef110
J. B. F. de Wit, P. Aggleton, T. Myers, M. Crewe. (2011) The rapidly changing paradigm of HIV prevention: time to strengthen social and behavioural approaches. Health Education Research 26:3, 381-392
CrossRef111
Margaret A. Lampe, Dawn K. Smith, Gillian J.E. Anderson, Ashley E. Edwards, Steven R. Nesheim. (2011) Achieving safe conception in HIV-discordant couples: the potential role of oral preexposure prophylaxis (PrEP) in the United States. American Journal of Obstetrics and Gynecology 204:6, 488.e1-488.e8
CrossRef112
Cohen, Myron S., Shaw, George M., McMichael, Andrew J., Haynes, Barton F., . (2011) Acute HIV-1 Infection. New England Journal of Medicine 364:20, 1943-1954
Full Text113
Andrew Anglemyer, George W Rutherford, Matthias Egger, Nandi Siegfried, George W Rutherford. 2011. Antiretroviral therapy for prevention of HIV transmission in HIV-discordant couples. .
CrossRef114
Barry R O’Keefe. (2011) Anti-HIV microbicide development: targeting the virus is the key. Future Virology 6:5, 553-556
CrossRef115
Mark A Wainberg, Hugh J Field. (2011) Proof of principle: antiretroviral drugs can prevent sexual transmission of HIV-1. Future Virology 6:5, 549-551
CrossRef116
HimaBindu Chunduri, Clyde Crumpacker, Prem L. Sharma. (2011) Reverse transcriptase mutation K65N confers a decreased replication capacity to HIV-1 in comparison to K65R due to a decreased RT processivity. Virology 414:1, 34-41
CrossRef117
Jessica E. Price, Willard Cates. (2011) Sex Worker Studies: The Science, Semantics, and Politics of Targeting Our HIV Prevention Response. Sexually Transmitted Diseases 38:5, 395-397
CrossRef118
(2011) Preexposure Chemoprophylaxis for HIV Prevention. New England Journal of Medicine 364:14, 1372-1375
Full Text119
P. Anton, B. C. Herold. (2011) HIV Transmission: Time for Translational Studies to Bridge the Gap. Science Translational Medicine 3:77, 77ps11-77ps11
CrossRef120
Elie Dolgin. (2011) Trial success spurs planning for rollout of HIV prevention pills. Nature Medicine 17:4, 392-392
CrossRef121
Amanda Clarke, Reshmie Ramautarsing, Pirapon June Ohata, Denise Hsu, Nadia Kancheva Landolt, Stephen J Kerr, Anchalee Avihingsanon, Wirach Maek-a-nantawat, Thanyawee Puthanakit, Torsak Bunupuradah, Wasana Prasitsuebsai, Jintanat Ananworanich, Kiat Ruxrungtham. (2011) The 14th Bangkok International Symposium on HIV Medicine. Future Virology 6:4, 409-412
CrossRef122
David Rey. (2011) Post-exposure prophylaxis for HIV infection. Expert Review of Anti-infective Therapy 9:4, 431-442
CrossRef123
Mian-er Cong, Ae S. Youngpairoj, Wutyi Aung, Sunita Sharma, James Mitchell, Charles Dobard, Walid Heneine, J. Gerardo Garcia-Lerma. (2011) Generation and mucosal transmissibility of emtricitabine- and tenofovir-resistant SHIV162P3 mutants in macaques. Virology 412:2, 435-440
CrossRef124
Kevin K. Ariën, Vicky Jespers, Guido Vanham. (2011) HIV sexual transmission and microbicides. Reviews in Medical Virology 21:2, 110-133
CrossRef125
Rebecca F Baggaley, Kimberly A Powers, Marie-Claude Boily. (2011) What do mathematical models tell us about the emergence and spread of drug-resistant HIV?. Current Opinion in HIV and AIDS 6:2, 131-140
CrossRef126
Brian S. Mustanski, Michael E. Newcomb, Steve N. Du Bois, Steve C. Garcia, Christian Grov. (2011) HIV in Young Men Who Have Sex with Men: A Review of Epidemiology, Risk and Protective Factors, and Interventions. Journal of Sex Research 48:2-3, 218-253
CrossRef127
Gavin M. Myers, Kenneth H. Mayer. (2011) Oral Preexposure Anti-HIV Prophylaxis for High-Risk U.S. Populations: Current Considerations in Light of New Findings. AIDS Patient Care and STDs 25:2, 63-71
CrossRef128
S. H. Vermund, L. Van Damme. (2011) HIV Prevention in Women: Next Steps. Science 331:6015, 284-284
CrossRef129
Mark A. Wainberg. (2011) AIDS: Drugs that prevent HIV infection. Nature 469:7330, 306-307
CrossRef130
Barry D Adam. (2011) Epistemic fault lines in biomedical and social approaches to HIV prevention. Journal of the International AIDS Society 14:Suppl 2, S2
CrossRef131
Richard G Wamai, Brian J Morris, Stefan A Bailis, David Sokal, Jeffrey D Klausner, Ross Appleton, Nelson Sewankambo, David A Cooper, John Bongaarts, Guy de Bruyn, Alex D Wodak, Joya Banerjee. (2011) Male circumcision for HIV prevention: current evidence and implementation in sub-Saharan Africa. Journal of the International AIDS Society 14:1, 49
CrossRef132
Kathleen M MacQueen. (2011) Framing the social in biomedical HIV prevention trials: a 20-year retrospective. Journal of the International AIDS Society 14:Suppl 2, S3
CrossRef133
Rony Zachariah, Wim Van Damme, Vic Arendt, Jean Schmit, Anthony D Harries. (2011) The HIV/AIDS epidemic in sub-Saharan Africa: thinking ahead on programmatic tasks and related operational research. Journal of the International AIDS Society 14:Suppl 1, S7
CrossRef134
Erik De Clercq. (2011) Acyclic nucleoside phosphonates: An unfinished story. Collection of Czechoslovak Chemical Communications 76:7, 829-842
CrossRef135
Robert Kalyesubula, Mark A. Perazella. (2011) Nephrotoxicity of HAART. AIDS Research and Treatment 2011, 1-11
CrossRef136
Brian Williams, Robin Wood, Victor Dukay, Wim Delva, David Ginsburg, John Hargrove, Martinus Stander, Robert Sheneberger, Julio Montaner, Alex Welte. (2011) Treatment as prevention: preparing the way. Journal of the International AIDS Society 14:Suppl 1, S6
CrossRef137
Michael, Nelson L., . (2010) Oral Preexposure Prophylaxis for HIV — Another Arrow in the Quiver?. New England Journal of Medicine 363:27, 2663-2665
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- Comments (8)
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8 Reader's Comments
MR CHARLES KWOBAH, MD | Student | Disclosure: NoneNAIROBI KenyaNovember 26, 2010SITUATION IN SUBSAHARAN AFRICA
The results of this study, if implemented in sub saharan africa could lead to a difficult situation since emtricitabine and tenofovir are considered 2nd line treatment and using these drugs for PRexProphylaxis could lead to widespread resistance, especially when poor adherence issues are factored in.
Jim Pickett | Other | Disclosure: NoneNovember 24, 2010Need for a rectal gel option
So, the study team found that about half of the men in the active arm of the trial were in fact not taking their pills regularly, if at all. It is not clear why this happened, but it certainly suggests that alternate means of using ARVs to prevent HIV infection may be more acceptable for these men.
The primary means of transmission among gay men and other MSM is through unprotected anal intercourse. If we develop an ARV as a gel or lubricant applied rectally – a rectal microbicide – it could be more acceptable for some individuals who don’t like taking pills. Many gay men and other MSM already use lubricants for anal intercourse, so they wouldn’t have to modify their behavior to achieve higher levels of protection with a rectal microbicide formulated as a lubricant. Adopting a new behavior—such as taking a pill every day—can be a considerable challenge for some. Please visit the homepage of IRMA - International Rectal Microbicide Advocates http://www.rectalmicrobicides.org for more info on the research and development of this strategy - including advocacy activities underway.EUGENE SEMON | Other | Disclosure: NoneRIDGEFIELD PARK NJNovember 24, 2010Risk Equation
With all due respect to the hard work this study represents: its results appear to offer nothing new for the practicing clinician - which I'm not. (But I can question.) Are old problems for clinicians dealing with NIH recommendations re HIV still unsolved, e.g. the "hit hard and early" debate?
Shouldn't differential diagnosis at least identify potential "elite controllers" when considering "pre-exposure prophylaxis"? Do the calculated risks of acquiring a LETHAL infection, say a number like 5% per year per individual MSM, consider the number of "elite controllers" expected from such a set of cohorts? After all, "long term non-progressors", as reported in this journal and many others, have ZERO RISK of an active, presumably immuno-destructive and lethal infection.James Sullivan | Physician | Disclosure: NoneNovember 23, 2010Wish less medicine could achieve same result
The cost of this intervention, and the possibility of doing harm to a healthy person, will limit the use of this intervention. The incidence of infections in the treated (and fairly adherent) group probably precludes trying a less expensive regimen, like "every Thursday, and then a dose after/at every sexual encounter," which would have cut the average use of drug in those treated by 50 to 80% (and therefore maybe cut the risks down, in addition to the expense). Someone will need to do a cost-benefit analysis showing if there is a savings to be had by delaying infection in persons with a 5% per year risk of infection. An algorithm of questions that identified which MSM might be valid candidates for the intervention is needed. In real life, the follow up won't be this intense, more likely q 3 or 4 months at best...which will increase the chance of engendering resistance in those with "breakthrough" infection, and which might result in less curbing of risky behavior than was seen during the study. I understand the fears that behavior will worsen because this option "permits" it, but this is the only thing that has worked convincingly so far in MSM. I do think true adherence would be better in an open label arm, with participant expectation of a benefit if they adhered. Perhaps a result better than 75% might actually be achievable under those conditions.
ilaboo lener | Other | Disclosure: NoneNovember 23, 2010A fantastic begining of the end of the begining
This title says it all for me.
Nick Williams | Other | Disclosure: NoneNovember 23, 2010Are you sure this worked? Doesn’t sound like it...
But there is a reduction in condom use in the research cohorts! When asked if they used pills faithfully study, participants said yes when the bio medical readings show the answer was actually no. Strikingly this lapse did not warrant a disqualification or a corruption of the study data? Similarly when asked if they used condoms, study participants said yes but they still got HIV. This is already a clinical research ethics issue which resulted in HIV infections because of bad study design wherein ethical questions were asked and ethical responses were given from respondents who had a preconceived knowledge of what it means, ethically, to tell an HIV researcher that you were using condoms less because you finally have access to PrEP. Additionally the threat of losing PrEP access, real or perceived is an ethical determinant and a possible driver of responses from enrollments. I would like to see incidence rates by study location for enrolled MSM population groups situated as a baseline to compare against sero-converts in the study. We can see if being in the study made you more likely to contract HIV than being in the MSM population by locality over time, as opposed to a cohort-based analysis that can't rule out study enrollment effects. The public health and ethical problems created by offering highly impacted populations a magic bullet for their ills is troubling and seductive, with obvious supplicant consequences. PrEP, on its best day is a complicated biomedical tool that should not stand in for a solution. This is what HIV prevention has come to: a Pharma advertisement for people who are not even infected yet and may be more likely to become so if you prescribe this to socially complicated, highly impacted patients and research subjects who have been waiting 30 years for a reprieve from a death sentence and celibacy.
DAVID COMPTON, MD | Physician | Disclosure: NoneWINGATE NCNovember 23, 2010Additional Protection
I understand the issue of additional protection, or any protection, in populations with a high incidence of HIV, but I worry that this will create a feeling of "I can't get it now" among those who take this chemoprophylaxis. Any subsequent reduction in the use of condoms by these individuals would be tragic.
- Letters
Can this study be generalized to all MSM?
This potentially life-or-death study retained about 68% of its subjects after 48 weeks, about 21% after 108 weeks, and about 5% after 132 weeks (Fig. 2). With such a high drop-out rate, it seems unlikely that the study-compliant are a representative sub-sample of the initial sample. With so many subjects 'missing-in-action,' the odds that this study has generated an approach that will work with most MSM are minimal.