Primary Outcomes

Description: The efficacy of once daily PrEP in preventing HIV-1 acquisition among uninfected heterosexuals in HIV-1 discordant partnerships, measured by calculating the HIV incidence per 100 person-years in each of three arms.

Measure: Incidence of HIV-1 Seroconversion Among HIV-1 Uninfected Participants

Time: Up to 36 months

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Description: Safety of daily TDF or FTC/TDF among HIV-1 uninfected individuals randomized to TDF or FTC/TDF compared to those randomized to placebo measured as the number of participants with Serious Adverse Events (SAEs) during follow-up.

Measure: Number of Participants With Serious Adverse Events (SAEs)

Time: Up to 36 months

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Secondary Outcomes

Description: Adherence to study medication as assessed by pill count at follow-up visits. We assessed the total number of doses taken of the total dispensed doses.

Measure: Study Drug Adherence: Total Number of Study Drug Doses Taken of the Total Dispensed Doses.

Time: Up to 36 months

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Description: Adherence to study drug measured as the percentage of visits when participants reported missing 1) any dose of study drug in the prior month and 2) 2 or more consecutive doses of study drug.

Measure: Study Drug Adherence: Self-reported Missed Doses of Study Drug

Time: Up to 36 months

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Description: HIV-1 resistance as measured by the number of seroconverters who had an HIV-1 reverse transcriptase mutation (K65R, K70E, M184I, or M184V) conferring resistance to TDF or FTC. These mutation types were pre-defined. Plasma samples for resistance testing were collected at the visit seroconversion was first detected and again at a visit within 1 month of seroconversion. Mutations detected at either of those visits are reported. Both seroconverters found to have a resistance mutation had been HIV infected at enrollment (TDF arm: n=1; FTC-TDF arm: n=1).

Measure: Number of Seroconverters With an HIV-1 Mutation Conferring Resistance to TDF or FTC

Time: Up to 36 months

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Description: Prevalence of STIs measured as the number of participants with a positive test result for N. gonorrhoeae, C. trachomatis, or T. vaginalis during follow-up. Participants were tested for STIs at annual follow-up visits and at intervening visits at which the participant presented with symptoms of an STI. Assessment for symptomatic sexually transmitted infections was conducted quarterly. N. gonorrhoeae and C. trachomatis testing were by APTIMA Combo 2 (Gen-Probe) or COBAS Amplicor (Roche Diagnostics). T. vaginalis testing was by APTIMA TV TMA (Gen-Probe) or In Pouch TV (Biomed Diagnostics).

Measure: Number of Participants With a Sexually Transmitted Infection (STI) During Follow-up

Time: Up to 36 months

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Description: Sexual risk behavior of participants, measured as the percentage of visits when participants reported having unprotected sex during follow-up.

Measure: Prevalence of Unprotected Sex During Follow-up

Time: Up to 36 months

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Description: Infant outcomes measured as the number of live-born infants born to female participants taking study drug that had any congenital anomalies.

Measure: Congenital Abnormalities Among Infants Born to Female Participants Taking Study Drug.

Time: Up to 36 months

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Description: The slope of the linear model of the growth of infants (length) during the entirety of follow-up. The length of the infant was measured as a z-score, in terms of standard deviations from the age and gender specific median using the World Health Organization growth curve, accounting for skewness. The slope, representing the change over time of the z-score, was calculated using all available z-scores over 12 months and regressing against study month.

Measure: Length Among Infants Born to Female Participants Taking Study Drug

Time: up to 12 months

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Description: The slope of the linear model of the growth of infants (weight) during the entirety of follow-up. The weight of the infant was measured as a z-score, in terms of standard deviations from the age and gender specific median using the World Health Organization growth curve, accounting for skewness. The slope, representing the change over time of the z-score, was calculated using all available z-scores over 12 months and regressing against study month.

Measure: Weight Among Infants Born to Female Participants Taking Study Drug

Time: up to 12 months

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Description: The slope of the linear model of the growth of infants (head circumference) during the entirety of follow-up. The head circumference of the infant was measured as a z-score, in terms of standard deviations from the age and gender specific median using the World Health Organization growth curve, accounting for skewness. The slope, representing the change over time of the z-score, was calculated using all available z-scores over 12 months and regressing against study month.

Measure: Head Circumference Among Infants Born to Female Participants Taking Study Drug

Time: up to 12 months

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Primary Outcomes

Description: Percentage of participants with a HIV-1 RNA < 50 copies per mL were assessed using FDA snapshot approach which defines a participant's virologic response status using only the viral load at the predefined time point within a window of time, along with study drug discontinuation status. If HIV RNA level is < 50 copies per mL at Week 48, it is considered as virologic success as per the snapshot approach.

Measure: Percentage of Participants With Human Immunodeficiency Virus (HIV)-1 Ribonucleic Acid (RNA) Less Than (<) 50 Copies Per Milliliter (Copies/mL) (Virologic Response) at Week 48 Defined by Food and Drug Administration (FDA) Snapshot Approach

Time: Week 48

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Secondary Outcomes

Description: Change from baseline in log10 HIV-1 RNA viral load (<50/200 copies/mL) at Weeks 2, 4, 8, 12, 24, 36, and 48 were reported.

Measure: Change From Baseline in log10 HIV-1 RNA Viral Load (<50/200 Copies/mL) at Weeks 2, 4, 8, 12, 24, 36, and 48

Time: Baseline, Weeks 2, 4, 8, 12, 24, 36, and 48

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Description: Percentage of participants with HIV-1 RNA < 50 copies/mL were reported.

Measure: Percentage of Participants With HIV-1 RNA < 50 Copies/mL at Week 24

Time: Week 24

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Description: The immunologic change was determined by changes in Cluster of CD4+ cell count. Change from baseline in CD4+ cell count at Weeks 12, 24 and 48 were assessed.

Measure: Change From Baseline in Cluster of Differentiation 4 (CD4+) Cell Count at Weeks 12, 24 and 48

Time: Baseline, Weeks 12, 24 and 48

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Description: Number of participants that required discontinuation after enrollment based on safety stopping rules were reported. Stopping rules include the following reasons: a). Estimated glomerular filtration rate (eGFR) according to the Modification of Diet in Renal Disease (MDRD) formula < 50 milliliter per minute (mL/min) b). Aspartate aminotransferase (AST) or alanine aminotransferase (ALT) greater than or equal to (>=) 2.5*upper limit of normal (ULN); c). Serum lipase >=1.5*ULN; d). Positive serum human chorionic gonadotropin pregnancy test (beta-hCG) for women of childbearing potential; e). Laboratory results that the investigator believes should result in discontinuation of study medication; f). Participants identified with active hepatitis C virus (HCV) infection that in the opinion of the investigator requires HCV treatment immediately or expected to be needed during the course of the study with agents not compatible with D/C/F/TAF FDC.

Measure: Number of Participants That Required Discontinuation After Enrollment Based on Safety Stopping Rules

Time: Up to Week 48

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Description: Percentage of participants discontinuing therapy due to AEs were reported. An AE was any untoward medical occurrence in a participant who received study drug without regard to possibility of causal relationship.

Measure: Percentage of Participants Discontinuing Therapy Due to Adverse Events (AEs)

Time: Up to Week 48

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Description: AE is any untoward medical occurrence in participant who received study drug without regard to possibility of causal relationship. Events with Grade 3 or higher (3=Severe; 4=life-threatening; 5=fatal) are events that significantly interrupt usual daily activity, require systemic drug therapy/other treatment and are, in many situations, considered unacceptable or intolerable events.

Measure: Percentage of Participants Experiencing Grade 3 and 4 Adverse Events

Time: Up to Week 48

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Description: Percentage of participants experiencing grade 3 and 4 laboratory abnormalities was assessed by Division of Acquired Immunodeficiency Syndrome (DAIDS) Adverse Event (AE) Grading Table. Abnormal laboratory values with Grade 3 or higher (3=Severe; 4=potentially life-threatening) signifies an interruption of usual daily activity, requiring systemic drug therapy/other treatment and are, in many situations, considered unacceptable or intolerable.

Measure: Percentage of Participants Experiencing Grade 3 and 4 Laboratory Abnormalities

Time: Up to Week 48

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Description: Percentage of participants meeting resistance stopping rules, requiring discontinuation of study treatment due to baseline resistance findings were reported. Investigator reviewed antiretroviral screening/baseline resistance data at Week 4, depending on availability of screening/baseline HIV genotypic drug resistance testing results from central laboratory. Participants who do not show full sensitivity to all drugs in the fixed-dose combination (FDC) study regimen according to the susceptibility assessment in the Genosure Prime report will be contacted to return to study site for early study treatment discontinuation (ESTD). Participants with identified resistance to lamivudine/Emtricitabine, attributed to the presence of the M184I/V mutation alone will be permitted to remain in the study.

Measure: Percentage of Participants Meeting Resistance Stopping Rules, Requiring Discontinuation of Study Treatment Due to Baseline Resistance Findings

Time: Up to Day 35

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Description: Percentage of Participants with resistance-associated mutations present at baseline were reported and included mutations in the domain of PR, RT (including nucleoside reverse transcriptase inhibitor [NRTIs] and non-nucleoside/nucleotide reverse transcriptase inhibitor [NNRTIs]), INI, RAMs as determined by the GenoSure Prime assay. Genotypes were not available for 7 participants due to failed amplification of viral deoxyribo nucleic acid (DNA) (that is, low viral load (VL) [<500 copies/mL], reduced viral fitness, compromised sample collection/handling, primer incompatibility).

Measure: Percentage of Participants With Baseline Protease (PI), Reverse Transcriptase (RT) and Integrase (INI)-Resistance-associated Mutation (RAMs)

Time: Baseline (Day 1)

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Description: Virologic failure is defined as: a) Virologic Nonresponse: HIV-1 RNA <1 log10 reduction from baseline, and HIV-1 RNA >= 400 copies/mL at the Week 12 visit, subsequently confirmed at an unscheduled visit conducted within 2 to 4 weeks after Week 12. b) Virologic Rebound: At any visit, after achieving confirmed consecutive HIV-1 RNA <50 copies/mL, a rebound in HIV 1 RNA to >= 50 copies/mL, which is subsequently confirmed at a scheduled or unscheduled visit conducted within 2 to 4 weeks of the HIV-1 RNA result; or At any visit, a >1 log10 increase in HIV-1 RNA from the nadir, which is subsequently confirmed at the following scheduled or unscheduled visit conducted within 2 to 4 weeks of the HIV-1 RNA result.

Measure: Percentage of Participants With Protocol-defined Virologic Failure (PDVF) at Week 24 and 48

Time: Week 24 and 48

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Description: Percentage of participants developing RAMs and loss of phenotypic susceptibility, upon meeting PDVF were reported. Virologic failure is defined as: a) Virologic Nonresponse: HIV-1 RNA <1 log10 reduction from baseline, and HIV-1 RNA greater than or equal to (>=) 400 copies/mL at the Week 12 visit, subsequently confirmed at an unscheduled visit conducted within 2 to 4 weeks after Week 12. b) Virologic Rebound: At any visit, after achieving confirmed consecutive HIV-1 RNA <50 copies/mL, a rebound in HIV 1 RNA to >= 50 copies/mL, which is subsequently confirmed at a scheduled or unscheduled visit conducted within 2 to 4 weeks of the HIV-1 RNA result; or At any visit, a >1 log10 increase in HIV-1 RNA from the nadir, which is subsequently confirmed at the following scheduled or unscheduled visit conducted within 2 to 4 weeks of the HIV-1 RNA result.

Measure: Percentage of Participants Developing Resistance-associated Mutation (RAMs) and Loss of Phenotypic Susceptibility, Upon Meeting Protocol-defined Virologic Failure (PDVF)

Time: Up to Week 48

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Description: Percentage of participants lost-to-follow-up throughout the 48 Weeks of treatment were reported.

Measure: Percentage of Participants Lost-to-Follow-up Throughout the 48 Weeks of Treatment

Time: Up to Week 48

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Description: Percentage of participants with retention in care completed and with documented clinical visit (within 90 days of discontinuation) were reported.

Measure: Percentage of Participants With Retention in Care Completed and With Documented Clinical Visit

Time: Up to Week 48

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Description: Percentage of participants with treatment adherence >95% based on pill count at Weeks 4, 8, 12, 24, 36, and 48 were reported. Treatment adherence was defined as having a treatment adherence of greater than (>) 95 percent (%) by pill count.

Measure: Percentage of Participants With Treatment Adherence >95% Based on Pill Count at Weeks 4, 8, 12, 24, 36, and 48

Time: Weeks 4, 8, 12, 24, 36, and 48

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Description: Percentage of participants with 100 % adherence based on participants self-report, using a 4-Day recall at Weeks 4, 8, 12, 24, 36, and 48 was reported.

Measure: Percentage of Participants With 100% Treatment Adherence Based on Participants Self-Report, Using a 4-Day Recall at Weeks 4, 8, 12, 24, 36, and 48

Time: Weeks 4, 8, 12, 24, 36, and 48

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Description: The HIV treatment satisfaction questionnaire (HIVTSQ) is based on a 10-item self-reported scale that measures overall satisfaction with treatment. The HIVTSQ items are summed up to produce a treatment satisfaction score (0 to 60) and an individual satisfaction rating for each item (0 to 6). The higher the score, the greater the treatment satisfaction.

Measure: Mean Total Scores for the HIV-Treatment Satisfaction Questionnaire (HIVTSQs) at Weeks 4, 24, and 48

Time: Weeks 4, 24, and 48

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Description: Number of participants with hospitalizations (overnight) was reported.

Measure: Number of Participants With Hospitalizations

Time: Up to Week 48

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Description: Duration of hospitalizations in days was reported for those participants hospitalized during the course of the study. Here, 'N' (number of participants analyzed) signifies those participants who were evaluable for this OM.

Measure: Duration of Hospitalizations

Time: Up to Week 48

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Description: Number of participants with outpatient visits (in addition to study visits, including General practitioner visit, Specialist visit, Nurse practitioner visit, Physician assistant visit, Home healthcare nurse visit and Other visit) was reported.

Measure: Number of Participants With Outpatient Visits

Time: Up to Week 48

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Description: Number of participants with emergency room visits was reported.

Measure: Number of Participants With Emergency Room Visits

Time: Up to Week 48

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Description: Median medical costs of care (United States of America [USA] dollars) based on healthcare resource utilization [HRU]) were reported. The cost of care specified for overnight hospitalization, hospital day care ward (without overnight), emergency room visit, general practitioner visit, specialist visit, nurse practitioner visit, physician assistant visit and Other visit.

Measure: Median Medical Costs of Care ((United States of America [USA] Dollars) Based on Healthcare Resource Utilization [HRU])

Time: Up to Week 48

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Description: Percentage of participants discontinuing therapy due to AEs were reported. An AE was any untoward medical occurrence in a participant who received study drug without regard to possibility of causal relationship.

Measure: Percentage of Participants Discontinuing Therapy Due to Adverse Events (AEs) Through Week 96

Time: Up to Week 96

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Description: AE is any untoward medical occurrence in participant who received study drug without regard to possibility of causal relationship. Events with Grade 3 or higher (3=Severe; 4=life-threatening; 5=fatal) are events that significantly interrupt usual daily activity, require systemic drug therapy/other treatment and are, in many situations, considered unacceptable or intolerable events.

Measure: Percentage of Participants Experiencing Grade 3 and 4 Adverse Events Through Week 96

Time: Up to Week 96

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Description: Percentage of participants experiencing grade 3 and 4 laboratory abnormalities were assessed by Division of Acquired Immunodeficiency Syndrome (DAIDS) Adverse Event (AE) Grading Table. Abnormal laboratory values with Grade 3 or higher (3=Severe; 4=potentially life-threatening) signifies an interruption of usual daily activity, requiring systemic drug therapy/other treatment and are, in many situations, considered unacceptable or intolerable.

Measure: Percentage of Participants Experiencing Grade 3 and 4 Laboratory Abnormalities Through Week 96

Time: Up to Week 96

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Description: Virologic failure is defined as: a) Virologic Nonresponse: HIV-1 RNA <1 log10 reduction from baseline, and HIV-1 RNA >= 400 copies/mL at the Week 12 visit, subsequently confirmed at an unscheduled visit conducted within 2 to 4 weeks after Week 12. b) Virologic Rebound: At any visit, after achieving confirmed consecutive HIV-1 RNA <50 copies/mL, a rebound in HIV 1 RNA to >= 50 copies/mL, which is subsequently confirmed at a scheduled or unscheduled visit conducted within 2 to 4 weeks of the HIV-1 RNA result; or At any visit, a >1 log10 increase in HIV-1 RNA from the nadir, which is subsequently confirmed at the following scheduled or unscheduled visit conducted within 2 to 4 weeks of the HIV-1 RNA result.

Measure: Percentage of Participants With Protocol-defined Virologic Failure (PDVF) at Week 72 and 96

Time: Weeks 72 and 96

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Primary Outcomes

Description: Proportion of subjects having achieved a virologic response for elvucitabine 10 mg/day in combination with efavirenz and tenofovir in HIV-1-infected subjects over 12 weeks compared with the proportion of subjects having achieved a virologic response for lamivudine 300 mg/day in combination with efavirenz and tenofovir. Virologic response was defined as having achieved undetectable (<50 copies/mL) HIV-1 RNA levels from baseline assessment.

Measure: The Proportion of Subjects With Virologic Response for 10 mg/Day Elvucitabine in HIV-1-infected Subjects by 12 Weeks Compared With the Proportion of Subjects With Lamivudine 300 mg/Day.

Time: 12 Weeks

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Description: Determination of the safety profile of elvucitabine as defined by the frequency, type and severity of treatment-emergent adverse events and the frequency of Grade 3 and Grade 4 laboratory abnormalities.

Measure: The Safety Profile of Elvucitabine.

Time: 12 Weeks

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Primary Outcomes

Measure: HIV-1 viral load

Time: up to 48 Weeks

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Secondary Outcomes

Measure: Incidence of adverse events

Time: up to 48 Weeks

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Measure: Changes in Immunologic Function (CD4 cell counts)

Time: from baseline to Weeks 18, 24, 30, 36, 42, 48

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Primary Outcomes

Measure: HIV-1 viral load

Time: change from baseline to Week 2

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Measure: Safety and Tolerability- Incidence of adverse events and laboratory abnormalities

Time: number and frequency from baseline through Week 12

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Secondary Outcomes

Measure: HIV-1 viral load

Time: change from baseline to Weeks 4, 8 and 12

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Measure: Changes in Immunologic Function (CD4 cell counts)

Time: changes from baseline to Weeks 4, 8 and 12

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Primary Outcomes

Description: Change in total energy expenditure (kcal/day)

Measure: Change in energy balance

Time: 24 weeks

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Primary Outcomes

Description: Participants were followed for up to 30 months. Person-years measures the amount of time for each participant, in years, from the date of enrollment to the date of the first HIV-positive test result if HIV-infected during follow-up or to the date of the last HIV-negative test result on follow-up if not HIV-infected during follow-up.

Measure: Person-years of Follow-up of Tenofovir 1% Gel and Vaginal Placebo Gel Arms

Time: For up to 30 months of follow-up

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Description: Participants were followed for up to 30 months. Participants were tested monthly for HIV-1 and positive rapid test results were confirmed by means of an enzyme-linked immunosorbent assay (EIA) and subsequent Western blotting (WB).

Measure: Number of HIV-1 Infections of Tenofovir 1% Gel and Vaginal Placebo Gel Arms

Time: For up to 30 months of follow-up

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Description: This is the number of HIV-1 infections divided by the amount of person-years of follow-up time to HIV-1 infection status, multiplied by 100 (per 100 person-years).

Measure: Incidence Rate of HIV-1 Infections of Tenofovir 1% Gel and Vaginal Placebo Gel Arms

Time: For up to 30 months of follow-up

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Description: Participants were followed for up to 30 months. Person-years measures the amount of time for each participant, in years, from the date of enrollment to the date of the first HIV-positive test result if HIV-infected during follow-up or to the date of the last HIV-negative test result on follow-up if not HIV-infected during follow-up. Note that the data for both of these arms were censored on the date when sites were asked to discontinue treatment in the oral TDF group.

Measure: Person-years of Follow-up of Oral TDF and Oral Placebo Arms

Time: For up to 30 months of follow-up

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Description: Participants were followed for up to 30 months. Participants were tested monthly for HIV-1 and positive rapid test results were confirmed by means of an enzyme-linked immunosorbent assay (EIA) and subsequent Western blotting (WB).

Measure: Number of HIV-1 Infections of Oral TDF and Oral Placebo Arms

Time: For up to 30 months of follow-up

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Description: This is the number of HIV-1 infections divided by the amount of person-years of follow-up time to HIV-1 infection status, multiplied by 100 (per 100 person-years).

Measure: Incidence Rate of HIV-1 Infections of Oral TDF and Oral Placebo Arms

Time: For up to 30 months of follow-up

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Description: Participants were followed for up to 30 months. Person-years measures the amount of time for each participant, in years, from the date of enrollment to the date of the first HIV-positive test result if HIV-infected during follow-up or to the date of the last HIV-negative test result on follow-up if not HIV-infected during follow-up.

Measure: Person-years of Follow-up of Oral TDF-FTC and Oral Placebo Arms

Time: For up to 30 months of follow-up

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Description: Participants were followed for up to 30 months. Participants were tested monthly for HIV-1 and positive rapid test results were confirmed by means of an enzyme-linked immunosorbent assay (EIA) and subsequent Western blotting (WB).

Measure: Number of HIV-1 Infections of Oral TDF-FTC and Oral Placebo Arms

Time: For up to 30 months of follow-up

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Description: This is the number of HIV-1 infections divided by the amount of person-years of follow-up time to HIV-1 infection status, multiplied by 100 (per 100 person-years).

Measure: Incidence Rate of HIV-1 Infections of Oral TDF-FTC and Oral Placebo Arms

Time: For up to 30 months of follow-up

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Description: This measure describes the number of participants with elevated serum creatinine levels, the only safety outcome of concern where a significant difference was detected between an active arm and the corresponding placebo arm.

Measure: Extended Safety of Daily Tenofovir 1% Gel, Oral TDF, and Oral FTC/TDF in Women at Risk for Sexually Transmitted HIV Infection Based on Occurrence of Grade 2, 3, and 4 Adverse Events

Time: Throughout study, up to 2.5 years

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Secondary Outcomes

Description: The primary resistance mutations for the study were pre-defined as K65R and K70E (which confer resistance to TDF), and M184I and M184V (which confer resistance to FTC), for their potential to cause a decrease in susceptibility to the study drug. K65R, K70E, and M184I were not detected in HIV-1 from any HIV-1 seroconverters while on study product. The number of HIV-1 seroconverters while on study with the M184V resistance mutation are reported for this outcome measure.

Measure: Frequency of HIV-1 Drug Resistance in Women Who Acquire HIV-1 Infection While Using Study Product

Time: Throughout study, up to 2.5 years

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Primary Outcomes

Description: The percentage of PAR with HIV-1 RNA virus <50 c/mL determined from blood samples drawn at Week 24 was tabulated by treatment arm with stratification by initial antiretroviral treatment. Per TLOVR algorithm, responders were PAR with confirmed viral load <50 c/mL who had not met any non-responder criterion. Non-responders were PAR who never achieved confirmed HIV RNA <50 c/mL, prematurely discontinued study or study medication for any reason, had confirmed rebound to at least 50 c/mL, or had an unconfirmed HIV RNA of at least 50 c/mL at the last visit.

Measure: Percentage of Participants (PAR) Who Achieved Plasma HIV-1 RNA <50 Copies (c)/Milliliter (mL) at the Week 24 Visit: TLOVR Analysis

Time: Week 24

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Secondary Outcomes

Description: The percentage of PAR with HIV-1 RNA virus <50 c/mL determined from blood samples drawn through Week 24 was tabulated by treatment arm with stratification by initial antiretroviral treatment using specific analysis methods.

Measure: Percentage of Participants (PAR) Who Achieved Plasma HIV-1 RNA <50 c/mL at the Week 24 Visit: Observed, M/D=F, and SNAPSHOT Analyses

Time: Week 24

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Description: The percentage of PAR with HIV-1 RNA virus <50 c/mL determined from blood samples drawn at Week 48 was tabulated by treatment arm with stratification by initial antiretroviral treatment using specific analysis methods.

Measure: Percentage of Participants (PAR) Who Achieved Plasma HIV-1 RNA <50 c/mL at the Week 48 Visit: TLOVR, Observed, M/D=F, and SNAPSHOT Analyses

Time: Week 48

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Description: The percentage of PAR with HIV-1 RNA virus <400 c/mL determined from blood samples drawn at Week 24 was tabulated by treatment arm with stratification by initial antiretroviral treatment. Per TLOVR algorithm, responders were PAR with confirmed viral load <400 c/mL who had not met any non-responder criterion. Non-responders were PAR who never achieved confirmed HIV RNA <400 c/mL, prematurely discontinued study or study medication for any reason, had confirmed rebound to at least 400 c/mL, or had an unconfirmed HIV RNA of at least 400 c/mL at the last visit.

Measure: Percentage of Participants (PAR) Who Achieved Plasma HIV-1 RNA <400 c/mL at the Week 24 Visit: TLOVR Analysis

Time: Week 24

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Description: The percentage of PAR with HIV-1 RNA virus <400 c/mL determined from blood samples drawn at Week 48 was tabulated by treatment arm with stratification by initial antiretroviral treatment. Per TLOVR algorithm, responders were PAR with confirmed viral load <400 c/mL who had not met any non-responder criterion. Non-responders were PAR who never achieved confirmed HIV RNA <400 c/mL, prematurely discontinued study or study medication for any reason, had confirmed rebound to at least 400 c/mL, or had an unconfirmed HIV RNA of at least 400 c/mL at the last visit.

Measure: Percentage of Participants (PAR) Who Achieved Plasma HIV-1 RNA <400 c/mL at the Week 48 Visit: TLOVR Analysis

Time: Week 48

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Description: The percentage of PAR with HIV-1 RNA virus <400 c/mL determined from blood samples drawn at Week 24 was tabulated by treatment arm with stratification by initial antiretroviral treatment using specific analysis methods.

Measure: Percentage of Participants (PAR) Who Achieved Plasma HIV-1 RNA <400 c/mL at the Week 24 Visit: Observed, MD=F, and SNAPSHOT Analyses

Time: Week 24

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Description: The percentage of PAR with HIV-1 RNA virus <400 c/mL determined from blood samples drawn at Week 48 was tabulated by treatment arm with stratification by initial antiretroviral treatment using specific analysis methods.

Measure: Percentage of Participants (PAR) Who Achieved Plasma HIV-1 RNA <400 c/mL at the Week 48 Visit: Observed, MD=F, and SNAPSHOT Analyses

Time: Week 48

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Description: Change from Baseline was calculated as the Week 24 value minus the Baseline value. Blood was drawn to analyze for plasma HIV viral load.

Measure: Change From Baseline in HIV-1 RNA at Week 24

Time: Baseline and Week 24

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Description: Change from Baseline was calculated as the Week 48 value minus the Baseline value. Blood was drawn to analyze for plasma HIV viral load.

Measure: Change From Baseline in HIV-1 RNA at Week 48

Time: Baseline and Week 48

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Description: Blood was drawn to analyze for CD4+ cell count. A CD4+ cell is a T lymphocyte that carries the CD4 antigen. Immunologic response was assessed by CD4+ counts. Change from Baseline was calculated as the Week 24 value minus the Baseline value.

Measure: Change From Baseline in CD4+ Cell Count at Week 24

Time: Baseline and Week 24

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Description: Blood was drawn to analyze for CD4+ cell count. A CD4+ cell is a T lymphocyte that carries the CD4 antigen. Immunologic response was assessed by CD4+ counts. Change from Baseline was calculated as the Week 48 value minus the Baseline value.

Measure: Change From Baseline in CD4+ Cell Count at Week 48

Time: Baseline and Week 48

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Description: Triglycerides, total cholesterol, HDL cholesterol, and LDL cholesterol levels were measured at Week 24. A Fasting blood sample was drawn to analyze for lipids. Change from Baseline was calculated as the Week 24 value minus the Baseline value for each parameter.

Measure: Change From Baseline in Fasting Triglycerides, Total Cholesterol, High-density Lipoprotein (HDL) Cholesterol, and Low-density Lipoprotein (LDL) Cholesterol at Week 24

Time: Baseline and Week 24

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Description: A Fasting blood sample was drawn to analyze for lipids. Change from Baseline was calculated as the Week 24 value minus the Baseline value.

Measure: Change From Baseline in Cholesterol/HDL Ratio at Week 24

Time: Baseline and Week 24

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Description: Triglycerides, total cholesterol, HDL cholesterol, and LDL cholesterol levels were measured or calculated at Week 48. A fasting blood sample was drawn to analyze for lipids. Change from Baseline was calculated as the Week 48 value minus the Baseline value for each parameter.

Measure: Change From Baseline in Fasting Triglycerides, Total Cholesterol, High-density Lipoprotein (HDL) Cholesterol, and Low-density Lipoprotein (LDL) Cholesterol at Week 48

Time: Baseline and Week 48

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Description: A fasting blood sample was drawn to analyze for lipids. Change from Baseline was calculated as the Week 48 value minus the Baseline value for each parameter.

Measure: Change From Baseline in Cholesterol/HDL Ratio at Week 48

Time: Baseline and Week 48

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Description: The number of participants that failed to remain virologically suppressed through 24 weeks on treatment was assessed. Viral failure is defined per protocol as confirmed HIV-1 RNA >=400 c/mL.

Measure: Number of Participants Who Met the Protocol-defined Confirmed Viral Failure Criteria Through Week 24

Time: From Baseline to Week 24

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Description: The number of participants that failed to remain virologically suppressed from baseline through 48 weeks on treatment was assessed. Viral failure is defined per protocol as confirmed HIV-1 RNA >=400 c/mL.

Measure: Number of Participants Who Met the Protocol-defined Confirmed Viral Failure Criteria Through Week 48

Time: From Baseline to Week 48

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Description: Death and clinical disease progression (as per CDC classification) were assessed from Baseline through Week 48. Disease progression is defined as progression from CDC Class A to B, Class A to C, or from Class B to C. AIDS CDC classifications are: Class A, Asymptomatic/lymphadenopathy/acute HIV; Class B, Symptomatic, not AIDS; Class C, AIDS indicator conditions. The CDC categorization of HIV/AIDS is based on the lowest documented CD4 cell count (Class A, >=500 cells per microliter [µl]; Class B, 200-499 cells/µl; Class C, <200 cells/µl) and on previously diagnosed HIV-related conditions.

Measure: Number of Participants Who Experienced Death and/or Disease Progression

Time: From Baseline to Week 48

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Description: A blood sample was drawn for particiapants with confirmed VF >=400 c/mL. For each participant, the mutations found at the time of failure were compared with any mutations found in the blood sample at Baseline. New resistance-associated viral mutations defined by the International Acquired Immunodeficiency Syndrome Society-United States of America guidelines present at the time of failure were tabulated by drug class. NRTI, nucleoside reverse transcriptase inhibitor; NNRTI, non-nucleoside reverse transcriptase inhibitor; PI, protease inhibitor.

Measure: Number of Confirmed Virologic Failure (VF) Participants (PAR) With Treatment-emergent HIV Genotypic Resistance in Reverse Transcriptase and Protease From Baseline Through Week 24

Time: From Baseline to Week 24

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Description: A blood sample was drawn for particiapants with confirmed VF >=400 c/mL. For each participant, the mutations found at the time of failure were compared with any mutations found in the blood sample at Baseline. New resistance-associated viral mutations defined by the International Acquired Immunodeficiency Syndrome Society-United States of America guidelines present at the time of failure were tabulated by drug class. NRTI, nucleoside reverse transcriptase inhibitor; NNRTI, non-nucleoside reverse transcriptase inhibitor; PI, protease inhibitor.

Measure: Number of Confirmed Virologic Failure (VF) Participants (PAR) With Treatment-emergent HIV Genotypic Resistance in Reverse Transcriptase and Protease From Baseline Through Week 48

Time: From Baseline to Week 48

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Description: A blood sample was drawn for participants failing to respond to therapy, and changes in drug susceptibility for HIV isolated from the participants for each drug used in the study were assessed. For each participant, the changes in drug susceptibility detected by phenotypic assay in virus from the sample collected at the time of failure was compared with drug susceptibility in the virus from the blood sample at Baseline.

Measure: Number of Confirmed Virologic Failure Participants (PAR) From Baseline Through Week 24 With the Indicated Treatment-emergent Reductions in Susceptibility to Abacavir, Lamivudine, Tenofovir, Emtricitabine, Atazanavir, or Ritonavir

Time: From Baseline to Week 24

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Description: A blood sample was drawn for participants failing to respond to therapy, and changes in drug susceptibility for HIV isolated from the participants for each drug used in the study were assessed. For each participant, the changes in drug susceptibility detected by phenotypic assay in virus from the sample collected at the time of failure was compared with drug susceptibility in the virus from the blood sample at Baseline.

Measure: Number of Confirmed Virologic Failure Participants (PAR) From Baseline Through Week 48 With the Indicated Treatment-emergent Reductions in Susceptibility to Abacavir, Lamivudine, Tenofovir, Emtricitabine, Atazanavir, or Ritonavir

Time: From Baseline to Week 48

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Description: The National Cancer Institute Common Terminology Criteria for Adverse Events (CTCAE) Version 3.0 is a descriptive terminology that can be utilized for AE reporting. A grading (severity) scale is provided for each AE. Grade refers to the severity of the adverse event (AE). The CTCAE v3.0 displays Grades 1 through 5 with unique clinical descriptions of severity for each AE based on this general guideline: Grade 1, mild AE; Grade 2, moderate AE; Grade 3, severe AE; Grade 4, life-threatening or disabling AE; Grade 5, death related to the AE.

Measure: Number of Participants With the Indicated Grade 2 to Grade 4 Adverse Events (AEs) Occurring at a Frequency of >=3% in Either Treatment Group

Time: From Baseline to Week 24

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Description: The National Cancer Institute Common Terminology Criteria for Adverse Events (CTCAE) Version 3.0 is a descriptive terminology that can be utilized for AE reporting. A grading (severity) scale is provided for each AE. Grade refers to the severity of the adverse event (AE). The CTCAE v3.0 displays Grades 1 through 5 with unique clinical descriptions of severity for each AE based on this general guideline: Grade 1, mild AE; Grade 2, moderate AE; Grade 3, severe AE; Grade 4, life-threatening or disabling AE; Grade 5, death related to the AE.

Measure: Number of Participants With the Indicated Grade 2 to Grade 4 Adverse Events (AEs) Occurring at a Frequency of >=3% in Either Treatment Group

Time: From Baseline to Week 48

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Primary Outcomes

Description: The percentage of participants with PVR for HIV-1 RNA cutoff at 50 copies/mL at Week 12 was summarized. PVR was the percentage of participants who did not have a confirmed virologic rebound. Virologic rebound was defined as 2 consecutive HIV-1 RNA values ≥ 50 copies/mL or the last available HIV-1 RNA value ≥ 50 copies/mL during the study followed by premature discontinuation from the study.

Measure: Percentage of Participants With Human Immunodeficiency Virus-1 Ribonucleic Acid (HIV-1 RNA) < 50 Copies/mL at Week 12 as Defined by Pure Virologic Response (PVR)

Time: Week 12

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Secondary Outcomes

Description: Development of new resistance mutations was assessed in participants who developed virologic failure, defined as 2 consecutive HIV-1 RNA result ≥ 50 copies/mL at any point in the study or with HIV-1 RNA ≥ 50 copies/mL at last visit.

Measure: Percentage of Participants With Emergence of New Mutations in HIV-1 Reverse Transcriptase and Integrase

Time: Day 1 up to 48 weeks

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Description: The percentage of participants with PVR for HIV-1 RNA cutoff at 50 copies/mL at Week 24 was summarized. PVR was the percentage of participants who did not have a confirmed virologic rebound. Virologic rebound was defined as 2 consecutive HIV-1 RNA values ≥ 50 copies/mL or the last available HIV-1 RNA value ≥ 50 copies/mL during the study followed by premature discontinuation from the study.

Measure: Percentage of Participants With HIV-1 RNA < 50 Copies/mL at Week 24 Using PVR

Time: Week 24

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Description: The percentage of participants with PVR for HIV-1 RNA cutoff at 50 copies/mL at Week 48 was summarized. PVR was the percentage of participants who did not have a confirmed virologic rebound. Virologic rebound was defined as 2 consecutive HIV-1 RNA values ≥ 50 copies/mL or the last available HIV-1 RNA value ≥ 50 copies/mL during the study followed by premature discontinuation from the study.

Measure: Percentage of Participants With HIV-1 RNA < 50 Copies/mL at Week 48 Using PVR

Time: Week 48

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Description: The percentage of participants with HIV-1 RNA < 50 copies/mL at Week 12 was also analyzed using the snapshot algorithm, which defines a participant's virologic response status using only the viral load at the predefined time point within an allowed window of time, along with study drug discontinuation status. Week 12 window was between Day 71 and 98 (inclusive).

Measure: Percentage of Participants With HIV-1 RNA < 50 Copies/mL at Week 12 Using the FDA Snapshot Analysis

Time: Week 12

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Description: The percentage of participants with HIV-1 RNA < 50 copies/mL at Week 24 was also analyzed using the snapshot algorithm, which defines a participant's virologic response status using only the viral load at the predefined time point within an allowed window of time, along with study drug discontinuation status. Week 24 window was between Day 141 and 210 (inclusive).

Measure: Percentage of Participants With HIV-1 RNA < 50 Copies/mL at Week 24 Using the FDA Snapshot Analysis

Time: Week 24

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Description: The percentage of participants with HIV-1 RNA < 50 copies/mL at Week 48 was also analyzed using the snapshot algorithm, which defines a participant's virologic response status using only the viral load at the predefined time point within an allowed window of time, along with study drug discontinuation status. Week 12 window was between Day 295 and 378 (inclusive).

Measure: Percentage of Participants With HIV-1 RNA < 50 Copies/mL at Week 48 Using the FDA Snapshot Analysis

Time: Week 48

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Description: The percentage of participants with HIV-1 RNA < 20 copies/mL at Week 12 was also analyzed using the snapshot algorithm, which defines a participant's virologic response status using only the viral load at the predefined time point within an allowed window of time, along with study drug discontinuation status. Week 12 window was between Day 71 and 98 (inclusive).

Measure: Percentage of Participants With HIV-1 RNA < 20 Copies/mL at Week 12 Using the FDA Snapshot Analysis

Time: Week 12

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Description: The percentage of participants with HIV-1 RNA < 20 copies/mL at Week 24 was also analyzed using the snapshot algorithm, which defines a participant's virologic response status using only the viral load at the predefined time point within an allowed window of time, along with study drug discontinuation status. Week 24 window was between Day 141 and 210 (inclusive).

Measure: Percentage of Participants With HIV-1 RNA < 20 Copies/mL at Week 24 Using the FDA Snapshot Analysis

Time: Week 24

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Description: The percentage of participants with HIV-1 RNA < 20 copies/mL at Week 48 was also analyzed using the snapshot algorithm, which defines a participant's virologic response status using only the viral load at the predefined time point within an allowed window of time, along with study drug discontinuation status. Week 12 window was between Day 295 and 378 (inclusive).

Measure: Percentage of Participants With HIV-1 RNA < 20 Copies/mL at Week 48 Using the FDA Snapshot Analysis

Time: Week 48

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Description: The percentage of participants with HIV-1 RNA < 50 copies/mL at Week 12 was analyzed using the M = F approach. In this approach, all missing data was treated as HIV-1 RNA ≥ 50 copies/mL.

Measure: Percentage of Participants With HIV-1 RNA < 50 Copies/mL at Week 12 Using the Missing = Failure (M = F) Approach

Time: Week 12

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Description: The percentage of participants with HIV-1 RNA < 50 copies/mL at Week 24 was analyzed using the M = F approach. In this approach, all missing data was treated as HIV-1 RNA ≥ 50 copies/mL.

Measure: Percentage of Participants With HIV-1 RNA < 50 Copies/mL at Week 24 Using the M = F Approach

Time: Week 24

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Description: The percentage of participants with HIV-1 RNA < 50 copies/mL at Week 48 was analyzed using the M = F approach. In this approach, all missing data was treated as HIV-1 RNA ≥ 50 copies/mL.

Measure: Percentage of Participants With HIV-1 RNA < 50 Copies/mL at Week 48 Using the M = F Approach

Time: Week 48

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Description: The percentage of participants with HIV-1 RNA < 50 copies/mL at Week 12 was also analyzed using the M = E approach. In this approach, all missing data was excluded in the computation of the proportions.

Measure: Percentage of Participants With HIV-1 RNA < 50 Copies/mL at Week 12 Using the Missing = Excluded (M = E) Approach

Time: Week 12

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Description: The percentage of participants with HIV-1 RNA < 50 copies/mL at Week 24 was also analyzed using the M = E approach. In this approach, all missing data was excluded in the computation of the proportions.

Measure: Percentage of Participants With HIV-1 RNA < 50 Copies/mL at Week 24 Using the M = E Approach

Time: Week 24

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Description: The percentage of participants with HIV-1 RNA < 50 copies/mL at Week 48 was also analyzed using the M = E approach. In this approach, all missing data was excluded in the computation of the proportions.

Measure: Percentage of Participants With HIV-1 RNA < 50 Copies/mL at Week 48 Using the M = E Approach

Time: Week 48

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Measure: Change From Baseline in Cluster Determinant 4+ (CD4+) Cell Count at Week 12

Time: Baseline (Day 1); Week 12

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Measure: Change From Baseline in CD4+ Cell Count at Week 24

Time: Baseline (Day 1); Week 24

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Measure: Change From Baseline in CD4+ Cell Count at Week 48

Time: Baseline (Day 1); Week 48

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Measure: Change From Baseline in CD4 Percentage (%) at Week 12

Time: Baseline (Day 1); Week 12

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Measure: Change From Baseline in CD4 % at Week 24

Time: Baseline (Day 1); Week 24

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Measure: Change From Baseline in CD4 % at Week 48

Time: Baseline (Day 1); Week 48

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