ABSTRACT
BACKGROUND: AZD2816 is a variant-adapted COVID-19 vaccine that expresses the full-length SARS-CoV-2 beta variant spike protein but is otherwise similar to AZD1222 (ChAdOx1 nCoV-19). This study aimed to evaluate the safety and immunogenicity of AZD1222 or AZD2816 (or both) primary-series vaccination in a cohort of adult participants who were previously unvaccinated. METHODS: In this phase 2/3, randomised, multinational, active-controlled, non-inferiority, immunobridging study, adult participants previously unvaccinated for COVID-19 were enrolled at 16 study sites in Brazil, South Africa, Poland, and the UK. Participants were stratified by age, sex, and comorbidity and randomly assigned 5:5:5:2 to receive a primary series of AZD1222 (AZD1222 group), AZD2816 (AZD2816 [4-week] group), or AZD1222-AZD2816 (AZD1222-AZD2816 group) at 4-week dosing intervals, or AZD2816 at a 12-week interval (AZD2816 [12-week] group) and evaluated for safety and immunogenicity through 180 days after dose 2. Primary outcomes were safety (rates of solicited adverse events occurring during 7 days and unsolicited adverse events occurring during 28 days after each dose) and immunogenicity (non-inferiority of pseudovirus neutralising antibody geometric mean titre [GMT], GMT ratio margin of 0·67, and seroresponse rate, rate difference margin of -10%, recorded 28 days after dose 2 with AZD2816 [4-week interval] against beta vs AZD1222 against ancestral SARS-CoV-2) in participants who were seronegative at baseline. This trial is registered with ClinicalTrials.gov, NCT04973449, and is completed. FINDINGS: Between July 7 and Nov 12, 2021, 1449 participants were assigned to the AZD1222 group (n=413), the AZD2816 (4-week) group (n=415), the AZD1222-AZD2816 group (n=412), and the AZD2816 (12-week) group (n=209). Ten (2·6%) of 378 participants who were seronegative at baseline in the AZD1222 group, nine (2·4%) of 379 in the AZD2816 (4-week) group, eight (2·1%) of 380 in the AZD1222-AZD2816 group, and 11 (5·8%) of 191 in the AZD2816 (12-week) group had vaccine-related unsolicited adverse events. Serious adverse events were recorded in one (0·3%) participant in the AZD1222 group, one (0·3%) in the AZD2816 (4-week) group, two (0·5%) in the AZD1222-AZD2816 group, and none in the AZD2816 (12-week) group. Co-primary immunogenicity endpoints were met: neutralising antibody GMT (ratio 1·19 [95% CI 1·08-1·32]; lower bound greater than 0·67) and seroresponse rate (difference 1·7% [-3·1 to 6·5]; lower bound greater than -10%) at 28 days after dose 2 were non-inferior in the AZD2816 (4-week) group against beta versus in the AZD1222 group against ancestral SARS-CoV-2. Seroresponse rates were highest with AZD2816 against beta (12-week interval 94·3% [95% CI 89·4-97·3]; 4-week interval 85·7% [81·5-89·2]) and with AZD1222 (84·6% [80·3-88·2]) against ancestral SARS-CoV-2. INTERPRETATION: Primary series of AZD1222 and AZD2816 were well tolerated, with no emergent safety concerns. Both vaccines elicited robust immunogenicity against beta and ancestral SARS-CoV-2 with greater responses demonstrated when testing against SARS-CoV-2 strains that matched those targeted by the respective vaccine. These findings demonstrate the continued importance of ancestral COVID-19 vaccines in protecting against severe COVID-19 and highlight the feasibility of using the ChAdOx1 platform to develop COVID-19 vaccines against future SARS-CoV-2 variants. FUNDING: AstraZeneca.
Subject(s)
COVID-19 Vaccines , COVID-19 , ChAdOx1 nCoV-19 , Immunogenicity, Vaccine , SARS-CoV-2 , Humans , Male , Female , Adult , Middle Aged , Double-Blind Method , COVID-19/prevention & control , COVID-19/immunology , United Kingdom , SARS-CoV-2/immunology , Brazil , COVID-19 Vaccines/immunology , COVID-19 Vaccines/adverse effects , COVID-19 Vaccines/administration & dosage , South Africa , Poland , Antibodies, Viral/blood , Antibodies, Neutralizing/blood , Aged , Vaccination/methods , Young AdultABSTRACT
BACKGROUND: There is a paucity of data on COVID-19 vaccines in people living with HIV-1, who could be at increased risk of severe illness and death from COVID-19. We evaluated the safety and immunogenicity of a Matrix-M adjuvanted recombinant spike protein nanoparticle COVID-19 vaccine (NVX-CoV2373; Novavax) in HIV-negative people and people living with HIV-1. METHODS: In this randomised, observer-blinded, multicentre, placebo-controlled phase 2A/B trial in South Africa, participants aged 18-84 years, with and without underlying HIV-1, were enrolled from 16 sites and randomly assigned (1:1) to receive two intramuscular injections of NVX-CoV2373 or placebo, 21 days apart. People living with HIV-1 were on stable antiretroviral therapy and had an HIV-1 viral load of less than 1000 copies per mL. Vaccine dosage was 5 µg SARS-CoV-2 recombinant spike protein with 50 µg Matrix-M adjuvant, whereas 0·9% saline was used as placebo injection (volume 0·5 mL each). All study staff and participants remained masked to study group assignment. We previously reported an interim analysis on the efficacy and safety of the NVX-CoV2373 vaccine (coprimary endpoints). In this Article, we present an expanded safety analysis for the full cohort of participants and report on the secondary objective of vaccine immunogenicity in the full cohort of people living with HIV-1 and in HIV-negative individuals overall and stratified by baseline SARS-CoV-2 serostatus. This trial is registered with ClinicalTrials.gov, NCT04533399, and the Pan-African Clinical Trials Registry, PACTR202009726132275. FINDINGS: Participants were enrolled between Aug 17 and Nov 25, 2020. The safety analysis set included 4164 HIV-negative participants (2089 in the intervention group and 2075 in the placebo group) and 244 people living with HIV-1 (122 in the intervention group and 122 in the placebo group). 1422 (34·1%) of 4164 HIV-negative people and 83 (34·0%) of 244 people living with HIV-1 were categorised as baseline SARS-CoV-2-positive (ie, anti-spike IgG reactive at enrolment or had a reactive SARS-CoV-2 nucleic acid amplification test by 14 days after the second study vaccination). In the NVX-CoV2373 group, solicited local and systemic adverse events were more common in HIV-negative participants (427 [30·6%] local and 401 [28·7%] systemic) than in people living with HIV-1 (20 [25·3%] local and 20 [25·3%] systemic) among those who were baseline SARS-CoV-2-seronegative (naive). Of the serious adverse events that occurred among HIV-negative people (of whom, two [0·1%] were baseline SARS-CoV-2-negative and four [0·6%] were baseline SARS-CoV-2-positive) and people living with HIV-1 (for whom there were no serious adverse events) in the NVX-CoV2373 group, none were assessed as related to the vaccine. Among participants who were baseline SARS-CoV-2-negative in the NVX-CoV2373 group, the anti-spike IgG geometric mean titres (GMTs) and seroconversion rates (SCRs) were lower in people living with HIV-1 (n=62) than in HIV-negative people (n=1234) following the first vaccination (GMT: 508·6 vs 1195·3 ELISA units [EU]/mL; SCR: 51·6% vs 81·3%); and similarly so 14 days after the second vaccination for GMTs (14â420·5 vs 31â631·8 EU/mL), whereas the SCR was similar at this point (100·0% vs 99·3%). In the NVX-CoV2373 group, anti-spike IgG GMTs 14 days after the second vaccination were substantially higher in those who were baseline SARS-CoV-2-positive than in those who were baseline SARS-CoV-2-seronegative for HIV-negative participants (100â666·1 vs 31â631·8 EU/mL) and for people living with HIV-1 (98â399·5 vs 14â420·5 EU/mL). This was also the case for angiotensin-converting enzyme 2 receptor-binding antibody and neutralising antibody titres. INTERPRETATION: The safety of the NVX-CoV2373 vaccine in people living with HIV-1 was similar to that in HIV-negative participants. However, people living with HIV-1 not previously exposed to SARS-CoV-2 had attenuated humoral immune responses to NVX-CoV2373 compared with their HIV-negative vaccine counterparts, but not so if they were baseline SARS-CoV-2-positive. FUNDING: Novavax and the Bill & Melinda Gates Foundation; investigational vaccine manufacturing support was provided by the Coalition for Epidemic Preparedness Innovations.
Subject(s)
COVID-19 , HIV Infections , HIV Seropositivity , HIV-1 , Nanoparticles , Viral Vaccines , Adjuvants, Immunologic , Antibodies, Viral , COVID-19/prevention & control , COVID-19 Vaccines/adverse effects , Humans , Immunoglobulin G , SARS-CoV-2 , Spike Glycoprotein, CoronavirusABSTRACT
This phase 2 study investigated long-term safety and efficacy of rilpivirine (RPV) plus two investigator-selected nucleos(t)ide reverse transcriptase inhibitors (NRTIs) in HIV-1-infected antiviral therapy-naive adolescents. Participants (≥12 to <18 years of age) were treated with RPV at 25 mg once daily (q.d.) plus 2 NRTIs and entered the treatment extension period for up to 240 weeks, with visits every 3 months. Long-term safety (analysis of adverse events [AEs] and laboratory results), efficacy (virologic response and outcome for patients with viral loads of <50 and <400 by time to loss of virologic response [TLOVR] and FDA Snapshot methods, as well as CD4+ cell count), and adherence (by pill count) for up to 240 weeks are presented. Twenty-four of 36 participants entered the treatment extension period, and 21 completed week 240. At week 240, a viral load of <50 copies/mL was achieved by 14/32 (43.8%) participants; virologic response by TLOVR was higher in participants with a baseline viral load of ≤100,000 copies/mL (48.0%) versus a viral load of >100,000 copies/mL (28.6%). By FDA Snapshot, a viral load of <50 copies/mL at week 240 was found in 53.1% (17/32) of participants with a baseline viral load of ≤100,000 copies/mL. Higher response was observed in participants with adherence of >95% and a baseline viral load of ≤100,000 copies/mL. Through week 240, 16/32 participants (50.0%) experienced virologic failure, including seven who developed treatment-emergent RPV resistance-associated mutations (RAMs [frequently E138K]): all 7 had ≥1 treatment-emergent NRTI RAM. No serious AEs after week 48, no discontinuations due to AEs between week 48 and week 240, and no new safety signals were observed. RPV did not affect pubertal development or adolescent growth. At the 5-year follow-up, efficacy was low in adolescents, particularly those with poor adherence and/or a high baseline viral load of >100,000 copies/mL. To limit the risk of virologic failure, RPV is restricted to patients with a baseline VL of ≤100,000 copies/mL in most countries. In addition, adequate treatment adherence to RPV treatment is imperative for long-term viral suppression and should be emphasized in the management of adolescents living with HIV. RPV exhibited a favorable long-term safety profile for adolescents living with HIV-1 with adequate adherence. (This study has been registered at ClinicalTrials.gov under identifier NCT00799864.).
Subject(s)
Anti-HIV Agents , HIV Infections , HIV-1 , Adolescent , Anti-HIV Agents/adverse effects , Anti-Retroviral Agents/therapeutic use , HIV Infections/drug therapy , HIV-1/genetics , Humans , Rilpivirine/adverse effects , Treatment Outcome , Viral LoadABSTRACT
BACKGROUND: The emergence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants threatens progress toward control of the coronavirus disease 2019 (Covid-19) pandemic. In a phase 1-2 trial involving healthy adults, the NVX-CoV2373 nanoparticle vaccine had an acceptable safety profile and was associated with strong neutralizing-antibody and antigen-specific polyfunctional CD4+ T-cell responses. Evaluation of vaccine efficacy was needed in a setting of ongoing SARS-CoV-2 transmission. METHODS: In this phase 2a-b trial in South Africa, we randomly assigned human immunodeficiency virus (HIV)-negative adults between the ages of 18 and 84 years or medically stable HIV-positive participants between the ages of 18 and 64 years in a 1:1 ratio to receive two doses of either the NVX-CoV2373 vaccine (5 µg of recombinant spike protein with 50 µg of Matrix-M1 adjuvant) or placebo. The primary end points were safety and vaccine efficacy against laboratory-confirmed symptomatic Covid-19 at 7 days or more after the second dose among participants without previous SARS-CoV-2 infection. RESULTS: Of 6324 participants who underwent screening, 4387 received at least one injection of vaccine or placebo. Approximately 30% of the participants were seropositive for SARS-CoV-2 at baseline. Among 2684 baseline seronegative participants (94% HIV-negative and 6% HIV-positive), predominantly mild-to-moderate Covid-19 developed in 15 participants in the vaccine group and in 29 in the placebo group (vaccine efficacy, 49.4%; 95% confidence interval [CI], 6.1 to 72.8). Vaccine efficacy among HIV-negative participants was 60.1% (95% CI, 19.9 to 80.1). Of 41 sequenced isolates, 38 (92.7%) were the B.1.351 variant. Post hoc vaccine efficacy against B.1.351 was 51.0% (95% CI, -0.6 to 76.2) among the HIV-negative participants. Preliminary local and systemic reactogenicity events were more common in the vaccine group; serious adverse events were rare in both groups. CONCLUSIONS: The NVX-CoV2373 vaccine was efficacious in preventing Covid-19, with higher vaccine efficacy observed among HIV-negative participants. Most infections were caused by the B.1.351 variant. (Funded by Novavax and the Bill and Melinda Gates Foundation; ClinicalTrials.gov number, NCT04533399.).
Subject(s)
COVID-19 Vaccines/immunology , COVID-19/prevention & control , Immunogenicity, Vaccine , SARS-CoV-2 , Adolescent , Adult , Aged , Aged, 80 and over , Antibodies, Neutralizing/blood , COVID-19/epidemiology , COVID-19/immunology , COVID-19/virology , COVID-19 Serological Testing , COVID-19 Vaccines/adverse effects , Double-Blind Method , HIV Seronegativity , HIV Seropositivity , Humans , Middle Aged , SARS-CoV-2/isolation & purification , South Africa , Young AdultABSTRACT
BACKGROUND: To evaluate the long-term safety and efficacy of rilpivirine (RPV), a non-nucleoside reverse transcriptase inhibitor (NNRTI), in combination with nucleoside/nucleotide reverse transcriptase inhibitors (NRTIs) in human immunodeficiency virus (HIV)-infected patients. METHODS: RPV-treated HIV-infected patients from phase 2b or 3 studies rolled-over into this phase 3, open-label study and received RPV 25 mg once daily (QD) with choice of two NRTIs. Adverse events (AEs), plasma viral load, CD4+ cell count, and antiviral resistance were evaluated. RESULTS: Of the 482 patients treated, 437 (>90%) patients discontinued study treatment; 371 (77%) had switched to commercially available RPV, 14 (2.9%) discontinued due to AEs, and 6 (1.2%) had virologic failure. In this rollover study, patients were followed up to week 336, although data was limited beyond 288 weeks. Forty-five (9.3%) patients were still undergoing treatment at the time of data cut-off for the current analysis (8 February 2018). The most frequently reported AEs were pregnancy in 7 (1.5%) patients and syphilis in 5 (1.0%) patients. Grade 3-4 AEs were reported in 17 (3.5%) patients, and AEs possibly related to RPV in 23 (4.8%) patients. Over 288 weeks of treatment, 80.1% (95% CI: 74.9%; 84.3%) of patients maintained virologic suppression (HIV-1 RNA <50 copies/mL). The absolute CD4+ cell count increased over time until week 192 and remained constant thereafter. CONCLUSIONS: RPV 25 mg QD in combination with an investigator-selected background regimen of two NRTIs demonstrated sustained long-term virologic suppression. The treatment was well-tolerated with no new safety findings.
Subject(s)
Anti-HIV Agents , HIV Infections , HIV-1 , Anti-HIV Agents/adverse effects , HIV Infections/drug therapy , Humans , Nucleosides/therapeutic use , Nucleotides/therapeutic use , Reverse Transcriptase Inhibitors/adverse effects , Rilpivirine/adverse effectsABSTRACT
The phase 3 ATLAS and FLAIR studies demonstrated that maintenance with Long-Acting (LA) intramuscular cabotegravir and rilpivirine is non-inferior in efficacy to current antiretroviral (CAR) oral therapy. Both studies utilized Patient-Reported Outcome instruments to measure treatment satisfaction (HIVTSQ) and acceptance (ACCEPT general domain), health status (SF-12), injection tolerability/acceptance (PIN), and treatment preference. In pooled analyses, LA-treated patients (n = 591) demonstrated greater mean improvements from baseline than the CAR group (n = 591) in treatment satisfaction (Week 44, + 3.9 vs. +0.5 HIVTSQs-points; p < 0.001) and acceptance (Week 48, +8.8 vs. +2.0 ACCEPT-points; p < 0.001). The acceptability of injection site reactions (PIN) significantly improved from week 5 (2.10 points) to week 48 (1.62 points; p < 0.001). In both studies, ≥ 97% of LA group participants with recorded data preferred LA treatment compared with prior oral therapy. These results further support the potential of a monthly injectable option for people living with HIV seeking an alternative to daily oral treatment.
Subject(s)
Anti-HIV Agents/therapeutic use , HIV Infections , HIV-1 , Pyridones/therapeutic use , Rilpivirine/therapeutic use , HIV Infections/drug therapy , Humans , Injections, Intramuscular , Patient Reported Outcome MeasuresABSTRACT
BACKGROUND: Long-acting injectable regimens may simplify therapy for patients with human immunodeficiency virus type 1 (HIV-1) infection. METHODS: We conducted a phase 3, randomized, open-label trial in which adults with HIV-1 infection who had not previously received antiretroviral therapy were given 20 weeks of daily oral induction therapy with dolutegravir-abacavir-lamivudine. Participants who had an HIV-1 RNA level of less than 50 copies per milliliter after 16 weeks were randomly assigned (1:1) to continue the current oral therapy or switch to oral cabotegravir plus rilpivirine for 1 month followed by monthly injections of long-acting cabotegravir plus rilpivirine. The primary end point was the percentage of participants who had an HIV-1 RNA level of 50 copies per milliliter or higher at week 48 (Food and Drug Administration snapshot algorithm). RESULTS: At week 48, an HIV-1 RNA level of 50 copies per milliliter or higher was found in 6 of 283 participants (2.1%) who received long-acting therapy and in 7 of 283 (2.5%) who received oral therapy (adjusted difference, -0.4 percentage points; 95% confidence interval [CI], -2.8 to 2.1), a result that met the criterion for noninferiority for the primary end point (margin, 6 percentage points). An HIV-1 RNA level of less than 50 copies per milliliter at week 48 was found in 93.6% who received long-acting therapy and in 93.3% who received oral therapy (adjusted difference, 0.4 percentage points; 95% CI, -3.7 to 4.5), a result that met the criterion for noninferiority for this end point (margin, -10 percentage points). Of the participants who received long-acting therapy, 86% reported injection-site reactions (median duration, 3 days; mild or moderate severity, 99% of cases); 4 participants withdrew from the trial for injection-related reasons. Grade 3 or higher adverse events and events that met liver-related stopping criteria occurred in 11% and 2%, respectively, who received long-acting therapy and in 4% and 1% who received oral therapy. Treatment satisfaction increased after participants switched to long-acting therapy; 91% preferred long-acting therapy at week 48. CONCLUSIONS: Therapy with long-acting cabotegravir plus rilpivirine was noninferior to oral therapy with dolutegravir-abacavir-lamivudine with regard to maintaining HIV-1 suppression. Injection-site reactions were common. (Funded by ViiV Healthcare and Janssen; FLAIR ClinicalTrials.gov number, NCT02938520.).
Subject(s)
Anti-HIV Agents/administration & dosage , HIV Infections/drug therapy , HIV-1/isolation & purification , Pyridones/administration & dosage , Rilpivirine/administration & dosage , Administration, Oral , Adult , Anti-HIV Agents/adverse effects , Anti-HIV Agents/blood , Anti-Retroviral Agents/therapeutic use , CD4 Lymphocyte Count , Drug Resistance, Viral/genetics , Drug Therapy, Combination , Female , HIV-1/genetics , Humans , Induction Chemotherapy , Injections, Intramuscular , Maintenance Chemotherapy , Male , Middle Aged , Mutation , Patient Reported Outcome Measures , Pyridones/adverse effects , Pyridones/blood , RNA, Viral/blood , Rilpivirine/adverse effects , Rilpivirine/blood , Viral LoadABSTRACT
BACKGROUND: Doravirine (DOR) demonstrated noninferior efficacy to darunavir plus ritonavir (DRV+r) and efavirenz (EFV) in 2 ongoing phase 3 trials: DRIVE-FORWARD (NCT02275780) and DRIVE-AHEAD (NCT02403674). METHODS: This prespecified analysis pooled efficacy data through the first 48 weeks of DRIVE-FORWARD and DRIVE-AHEAD from the DOR groups (DOR/lamivudine [3TC]/tenofovir disoproxil fumarate [TDF] or DOR [100 mg daily] with emtricitabine [FTC]/TDF or abacavir [ABC]/3TC [n = 747]) compared with DRV+r (800/100 mg daily) with FTC/TDF or ABC/3TC (n = 383) or EFV/FTC/TDF (600/200/300 mg daily; n = 364). Efficacy assessments included the proportion of participants with human immunodeficiency virus type 1 (HIV-1) RNA <50 copies/mL and change in CD4+ T-cell count. RESULTS: At week 48, DOR demonstrated noninferior efficacy to DRV+r and EFV, with 84.1% of DOR-treated participants achieving HIV-1 RNA <50 copies/mL compared with 79.9% of the DRV+r and 80.8% of the EFV groups. Results were similar across demographic/prognostic subpopulations, including baseline plasma HIV-1 RNA, gender, race, and HIV-1 subtype. Mean increases from baseline in CD4+ T-cell count through 48 weeks were 195.5 cells/mm3 for DOR, 185.6 cells/mm3 for DRV+r, and 188.4 cells/mm3 for EFV/FTC/TDF. CONCLUSIONS: DOR, as a single entity (in combination with other antiretroviral agents) and as a fixed-dose combination (DOR/3TC/TDF), demonstrated noninferior efficacy to DRV+r and EFV as assessed by the proportion of HIV-1-infected, treatment-naive adults with HIV-1 RNA <50 copies/mL. CLINICAL TRIALS REGISTRATION: NCT02275780 and NCT02403674.
Subject(s)
Anti-HIV Agents , HIV Infections , HIV-1 , Adult , Anti-HIV Agents/therapeutic use , Anti-Retroviral Agents/therapeutic use , Antiretroviral Therapy, Highly Active , Emtricitabine/therapeutic use , HIV Infections/drug therapy , Humans , Lamivudine/therapeutic use , Pyridones , Treatment Outcome , TriazolesABSTRACT
BACKGROUND: Doravirine is a novel, non-nucleoside reverse transcriptase inhibitor that has shown non-inferior efficacy to ritonavir-boosted darunavir, with a superior lipid profile, in adults with HIV who were treatment naive at week 48 in the phase 3 DRIVE-FORWARD trial. Here we present the 96-week data for the study. METHODS: This randomised, controlled, double-blind, multicentre, non-inferiority, phase 3 study was undertaken at 125 clinical centres in 15 countries. Eligible participants were adults (aged ≥18 years) infected with HIV-1 who were naive to antiretroviral therapy, with a plasma HIV-1 RNA concentration of 1000 copies per mL or higher at screening, and no known resistance to any of the study drugs. Participants were randomly assigned (1:1) using an interactive voice and web response system, stratified by baseline HIV-1 RNA concentration and background nucleoside reverse transcriptase inhibitor therapy, to doravirine (100 mg per day) or ritonavir-boosted darunavir (100 mg ritonavir and 800 mg darunavir per day), both with investigator-selected nucleoside reverse transcriptase inhibitors: emtricitabine and tenofovir disoproxil fumarate or abacavir and lamivudine. Participants and investigators were masked to treatment assignment until week 96. The primary efficacy endpoint was the proportion of participants who had a plasma HIV-1 RNA concentration of less than 50 copies per mL at week 48, which has been reported previously. Here we report the key secondary efficacy endpoint of the proportion of participants who achieved this concentration by week 96, assessed in all participants who received at least one dose of any study drug, regardless of whether it was their randomly assigned treatment. We used a US Food and Drug Administration snapshot approach and a margin of 10 percentage points to define the non-inferiority of doravirine to ritonavir-boosted darunavir at 96 weeks. Key safety endpoints were change in fasting serum lipid concentrations, the incidence of adverse events, and time to discontinuation due to an adverse event, assessed in all participants who received at least one dose of any study medication. This study is registered with ClinicalTrials.gov, NCT02275780, and is closed to accrual. FINDINGS: Between Dec 1, 2014, and Oct 20, 2015, 1027 individuals were screened, of whom 769 participants were randomly assigned to doravirine (n=385) or ritonavir-boosted darunavir (n=384), and 383 in both groups were given at least one dose of their allocated treatment. Most participants were male (645 [84%] of 766) and white (560 [73%]), with a mean age of 35·2 years (SD 10·6). 292 participants in the doravirine group and 273 in the darunavir group completed 96 weeks of treatment. At week 96, a higher proportion of the doravirine group (277 [73%] of 383) achieved an HIV-1 RNA concentration of less than 50 copies per mL than did of the darunavir group (248 [66%] of 383; difference 7·1%, 95% CI 0·5-13·7). Responses were similar regardless of baseline characteristics. Treatment-emergent resistance to any study drug occurred in two (1%) of 383 participants in the doravirine group and one (<1%) of 383 in the ritonavir-boosted darunavir group. Significant differences were seen between treatment groups in mean changes from baseline in LDL cholesterol (-14·6 mg/dL, 95% CI -18·2 to -11·0) and non-HDL cholesterol (-18·4 mg/dL, -22·5 to -14·3). Frequencies of adverse events were similar between groups. No significant treatment difference (log-rank nominal p=0·063) through week 96 was observed in time to discontinuation due to an adverse event. The most common adverse events (week 0-96) were diarrhoea (65 [17%] in the doravirine group vs 91 [24%] in the ritonavir-boosted darunavir group), nausea (45 [12%] vs 52 [14%]), headache (57 [15%] vs 46 [12%]), and upper respiratory tract infection (51 [13%] vs 30 [8%]). Two participants, one in each group, died during treatment; neither death was considered to be related to study medication. INTERPRETATION: These results through 96 weeks support the efficacy and safety results reported previously for doravirine at 48 weeks, supporting the use of doravirine for the long-term treatment of adults with previously untreated HIV-1 infection. FUNDING: Merck.
Subject(s)
Anti-HIV Agents/administration & dosage , Darunavir/administration & dosage , HIV Infections/drug therapy , Pyridones/administration & dosage , Ritonavir/administration & dosage , Triazoles/administration & dosage , Adult , Anti-HIV Agents/adverse effects , Darunavir/adverse effects , Double-Blind Method , Female , HIV-1/drug effects , HIV-1/physiology , Humans , Male , Middle Aged , Pyridones/adverse effects , Ritonavir/adverse effects , Triazoles/adverse effects , Young AdultABSTRACT
GSK3532795 (formerly known as BMS-955176) is a second-generation maturation inhibitor targeting a specific Gag cleavage site between capsid p24 and spacer peptide 1 of HIV-1. Study 205891 (previously AI468038) investigated the efficacy, safety, and dose response of GSK3532795 in treatment-naive, HIV-1-infected participants. Study 205891 (NCT02415595) was a Phase IIb, randomized, active-controlled, double-blind, international trial. Participants were randomized 1:1:1:1 to one of three GSK3532795 arms at doses 60 mg, 120 mg or 180 mg once daily (QD), or to efavirenz (EFV) at 600 mg QD, each in combination with tenofovir disoproxil fumarate and emtricitabine (TDF/FTC) (300/200 mg QD). Primary endpoint was proportion of participants with plasma HIV-1 RNA <40 copies/mL at Week 24. Between May 2015 and May 2016, 206 participants received treatment. At Week 24, 76-83% participants receiving GSK3532795 and 77% receiving EFV achieved HIV-1 RNA <40 copies/mL. Fifteen participants receiving GSK3532795 and one receiving EFV met resistance testing criteria; 10/15 receiving GSK3532795 had emergent substitutions at reverse transcriptase positions M184, and one at position K65, while the participant receiving EFV did not have any nucleoside reverse transcriptase inhibitor (NRTI)/non-NRTI mutations. EFV, relative to GSK3532795, had more serious adverse events (9% versus 5%) and adverse events leading to discontinuation (17% versus 5%). However, 3-4-fold higher rates of gastrointestinal adverse events were observed with GSK3532795 relative to EFV. GSK3532795 combined with TDF/FTC is efficacious with 24 weeks of therapy. However, GSK3532795 showed a higher rate of gastrointestinal intolerability and treatment-emergent resistance to the NRTI backbone relative to EFV. Trial registration: ClinicalTrials.gov NCT02415595.
Subject(s)
Anti-HIV Agents/therapeutic use , Emtricitabine/therapeutic use , HIV Infections/drug therapy , Tenofovir/therapeutic use , Triterpenes/therapeutic use , Adult , Alkynes , Anti-HIV Agents/pharmacokinetics , Benzoxazines/pharmacokinetics , Benzoxazines/therapeutic use , Cyclopropanes , Double-Blind Method , Drug Administration Schedule , Drug Resistance, Viral , Drug Therapy, Combination , Emtricitabine/pharmacokinetics , Female , HIV-1/genetics , HIV-1/isolation & purification , Half-Life , Humans , Male , Middle Aged , RNA, Viral/blood , Tenofovir/pharmacokinetics , Treatment Outcome , Triterpenes/pharmacokineticsABSTRACT
BACKGROUND: Doravirine is a novel non-nucleoside reverse transcriptase inhibitor (NNRTI) with a pharmacokinetic profile supporting once-daily dosing, and potent in-vitro activity against the most common NNRTI-resistant HIV-1 variants. We compared doravirine with ritonavir-boosted darunavir, when both were given with two nucleoside reverse transcriptase inhibitors (NRTIs), in adults with previously untreated HIV-1 infection. METHODS: In this randomised, controlled, double-blind, multicentre, non-inferiority trial, adults with HIV-1 infection were screened and enrolled at 125 clinical centres in 15 countries. Eligible participants (aged ≥18 years) were naive to antiretroviral therapy with plasma HIV-1 RNA of at least 1000 copies per mL at screening. Participants who had previously been treated for a viral infection other than HIV-1, those taking immunosuppressive drugs, and individuals with active acute hepatitis were excluded. Participants were randomly assigned (1:1) via an interactive voice and web response system to receive oral doravirine 100 mg or darunavir 800 mg plus ritonavir 100 mg once daily, with two investigator-selected NRTIs (tenofovir and emtricitabine or abacavir and lamivudine) for up to 96 weeks. Randomisation was stratified by HIV-1 RNA measurements at screening (≤100â000 vs >100â000 copies per mL) and the NRTI pair. Study participants, funding institution staff, investigators, and study site personnel were masked to treatment group assignment. The primary efficacy endpoint was the proportion of participants achieving HIV-1 RNA of less than 50 copies per mL at week 48 defined by the US Food and Drug Administration snapshot algorithm, with non-inferiority established if the lower bound of the two-sided 95% CI for the treatment difference (doravirine minus darunavir) was greater than -10 percentage points. All participants who received at least one dose of study drug were included in the primary efficacy and safety analyses. This trial is active, but not recruiting, and is registered with ClinicalTrials.gov, number NCT02275780. FINDINGS: Between Dec 1, 2014, and Oct 20, 2015, 1027 participants were screened for eligibility, of whom 769 participants were randomly assigned to treatment (385 with doravirine and 384 with ritonavir-boosted darunavir). 56 participants discontinued treatment in the doravirine group compared with 71 in the darunavir group, mostly due to loss to follow-up. 383 participants who received doravirine and 383 who received darunavir were included in the primary efficacy analyses. At week 48, 321 (84%) participants in the doravirine group and 306 (80%) in the darunavir group achieved plasma HIV-1 RNA of less than 50 copies per mL (difference 3·9%, 95% CI -1·6 to 9·4), indicating non-inferiority of the doravirine regimen. The most common study drug-related adverse events were diarrhoea (21 [5%] of 383 participants in the doravirine group and 49 [13%] of 383 participants in the darunavir group), nausea (25 [7%] vs 29 [8%]), and headache (23 [6%] vs ten [3%]). 18 participants (six [2%] of 383 participants in the doravirine group vs 12 [3%] of 383 participants in the darunavir group) discontinued treatment due to adverse events, which were considered drug-related in four (1%) participants in the doravirine group and 8 (2%) participants in the darunavir group. Serious adverse events occurred in 19 (5%) of 383 participants in the doravirine group and 23 (6%) of 383 in the darunavir roup, and were considered study-drug related in one (<1%) participant of each group. INTERPRETATION: In treatment-naive adults with HIV-1 infection, doravirine combined with two NRTIs might offer a valuable treatment option for adults with previously untreated HIV-1 infection. FUNDING: Merck & Co.
Subject(s)
Anti-HIV Agents/administration & dosage , Antiretroviral Therapy, Highly Active/methods , Darunavir/administration & dosage , HIV Infections/drug therapy , Pyridones/administration & dosage , Ritonavir/administration & dosage , Triazoles/administration & dosage , Adult , Double-Blind Method , Drug-Related Side Effects and Adverse Reactions/epidemiology , Drug-Related Side Effects and Adverse Reactions/pathology , Female , HIV Infections/virology , HIV-1/isolation & purification , Humans , Male , Middle Aged , RNA, Viral/blood , Treatment Outcome , Viral LoadABSTRACT
BACKGROUND: Lipoatrophy is one of the most feared complications associated with the use of nucleoside or nucleotide reverse transcriptase inhibitors (N[t]RTIs). We aimed to assess soft-tissue changes in participants with HIV who had virological failure of a first-line antiretroviral (ART) regimen containing a non-nucleoside reverse transcriptase inhibitor plus two N(t)RTIs and were randomly assigned to receive a second-line regimen containing a boosted protease inhibitor given with either N(t)RTIs or raltegravir. METHODS: Of the 37 sites that participated in the randomised, open-label, non-inferiority SECOND-LINE study, eight sites from five countries (Argentina, India, Malaysia, South Africa, and Thailand) participated in the body composition substudy. All sites had a dual energy x-ray absorptiometry (DXA) scanner and all participants enrolled in SECOND-LINE were eligible for inclusion in the substudy. Participants were randomly assigned (1:1), via a computer-generated allocation schedule, to receive either ritonavir-boosted lopinavir plus raltegravir (raltegravir group) or ritonavir-boosted lopinavir plus two or three N(t)RTIs (N[t]RTI group). Randomisation was stratified by site and screening HIV-1 RNA. Participants and investigators were not masked to group assignment, but allocation was concealed until after interventions were assigned. DXA scans were done at weeks 0, 48, and 96. The primary endpoint was mean percentage and absolute change in peripheral limb fat from baseline to week 96. We did intention-to-treat analyses of available data. This substudy is registered with ClinicalTrials.gov, number NCT01513122. FINDINGS: Between Aug 1, 2010, and July 10, 2011, we recruited 211 participants into the substudy. The intention-to-treat population comprised 102 participants in the N(t)RTI group and 108 participants in the raltegravir group, of whom 91 and 105 participants, respectively, reached 96 weeks. Mean percentage change in limb fat from baseline to week 96 was 16·8% (SD 32·6) in the N(t)RTI group and 28·0% (37·6) in the raltegravir group (mean difference 10·2%, 95% CI 0·1-20·4; p=0·048). Mean absolute change was 1·04 kg (SD 2·29) in the N(t)RTI group and 1·81 kg (2·50) in the raltegravir group (mean difference 0·6, 95% CI -0·1 to 1·3; p=0·10). INTERPRETATION: Our findings suggest that for people with virological failure of a first-line regimen containing efavirenz plus tenofovir and lamivudine or emtricitabine, the WHO-recommended switch to a ritonavir-boosted protease inhibitor plus zidovudine (a thymidine analogue nucleoside reverse transcriptase inhibitor) and lamivudine might come at the cost of peripheral lipoatrophy. Further study could help to define specific groups of people who might benefit from a switch to an N(t)RTI-sparing second-line ART regimen. FUNDING: The Kirby Institute and the Australian National Health and Medical Research Council.
Subject(s)
Anti-HIV Agents/therapeutic use , Body Composition , HIV Infections/drug therapy , HIV-Associated Lipodystrophy Syndrome/epidemiology , Lopinavir/therapeutic use , Raltegravir Potassium/therapeutic use , Reverse Transcriptase Inhibitors/therapeutic use , Ritonavir/therapeutic use , Absorptiometry, Photon , Adult , Anti-HIV Agents/administration & dosage , Anti-HIV Agents/adverse effects , Antiretroviral Therapy, Highly Active , CD4 Lymphocyte Count , Drug Therapy, Combination , Emtricitabine/administration & dosage , Emtricitabine/adverse effects , Female , HIV Infections/metabolism , HIV Infections/virology , HIV Protease Inhibitors/administration & dosage , HIV Protease Inhibitors/adverse effects , HIV-1/drug effects , Humans , International Cooperation , Lamivudine/administration & dosage , Lamivudine/adverse effects , Lopinavir/administration & dosage , Lopinavir/adverse effects , Male , Raltegravir Potassium/administration & dosage , Raltegravir Potassium/adverse effects , Reverse Transcriptase Inhibitors/administration & dosage , Reverse Transcriptase Inhibitors/adverse effects , Ritonavir/administration & dosage , Ritonavir/adverse effects , Tenofovir/administration & dosage , Tenofovir/adverse effects , Viral LoadABSTRACT
BACKGROUND: Rilpivirine 25 mg qd yields similar exposure in adolescents and adults (Pediatric study in Adolescents Investigating a New NNRTI TMC278 [PAINT] Cohort 1, Part 1). We report rilpivirine safety, efficacy, virology and pharmacokinetics in adolescents during 48 weeks of treatment (Cohort 1, Part 2). METHODS: PAINT (NCT00799864) is a phase II, ongoing, open-label, single-arm trial of rilpivirine plus 2 investigator-selected nucleoside/nucleotide reverse-transcriptase inhibitors. Cohort 1 of PAINT includes treatment-naïve HIV-1-infected adolescents (≥12 to <18 years). Following approval in adults and after Part 1a in Cohort 1, enrollment was restricted to screening viral load (VL) ≤100,000 copies/mL. RESULTS: Overall, 20 (56%) of 36 patients were women, 18 (50%) were aged ≥12 to <15 years, 32 (89%) were Black or African American, mostly from South Africa or Uganda, and 28 (78%) had baseline VL ≤100,000 copies/mL. At week 48, adverse events considered possibly related to treatment occurred in 13 (36%) patients, mostly (excluding investigations) somnolence (n = 5, 14%) and nausea (n = 2, 6%). Most adverse events were grade 1 or 2, and 7 (19%) patients had grade 3 or 4 adverse events. Week 48 virologic response (VL <50 copies/mL, time-to-loss-of-virologic-response) was achieved in 26 of the 36 (72%) patients: 22 of the 28 (79%) with baseline VL ≤100,000 copies/mL and 4 of the 8 (50%) with baseline VL >100,000 copies/mL. Median (range) CD4 count increased by 184 (-135 to 740) cells/mm at week 48. Eight patients experienced virologic failure, including 5 who developed rilpivirine resistance-associated mutations, mostly E138K, K101E and M230L. Mean (standard deviation) rilpivirine area-under-the-concentration-time curve from 0 to 24 hours (AUC24h and C0h) were 2391 (991) ng·h/mL and 83.5 (38.7) ng/mL, respectively. CONCLUSIONS: Rilpivirine safety, virologic and pharmacokinetic profiles were similar in treatment-naïve HIV-1-infected adolescents and adults, supporting use of rilpivirine 25 mg qd, plus other antiretrovirals, in treatment-naïve adolescents with VL ≤100,000 copies/mL at treatment initiation.
Subject(s)
Anti-Retroviral Agents/therapeutic use , HIV Infections/drug therapy , Rilpivirine/therapeutic use , Adolescent , Anti-Retroviral Agents/adverse effects , Anti-Retroviral Agents/pharmacokinetics , Child , Female , HIV Infections/virology , Humans , Male , Medication Adherence , Rilpivirine/adverse effects , Rilpivirine/pharmacokinetics , Treatment OutcomeABSTRACT
Oral emtricitabine/tenofovir disoproxil fumarate (FTC/TDF) has been evaluated as pre-exposure prophylaxis (PrEP). We describe the accuracy of self-reported adherence to FTC/TDF and pill counts when compared to drug concentrations in the FEM-PrEP trial. Using drug concentrations of plasma tenofovir (TFV) and intracellular tenofovir diphosphate (TFVdp) among a random sub-sample of 150 participants assigned to FTC/TDF, we estimated the positive predictive value (PPV) of four adherence measures. We also assessed factors associated with misreporting of adherence using multiple drug-concentration thresholds and explored pill use and misreporting using semi-structured interviews (SSIs). Reporting use of ≥1 pill in the previous 7 days had the highest PPV, while pill-count data consistent with missing ≤1 day had the lowest PPV. However, all four measures demonstrated poor PPV. Reported use of oral contraceptives (OR 2.26; p = 0.014) and weeks of time in the study (OR 1.02; p < 0.001) were significantly associated with misreporting adherence. Although most SSI participants said they did not misreport adherence, participant-dependent adherence measures were clearly unreliable in the FEM-PrEP trial. Pharmacokinetic monitoring remains the measure of choice until more reliable participant-dependent measures are developed.
Subject(s)
Adenine/therapeutic use , Anti-HIV Agents/therapeutic use , HIV Infections/prevention & control , Medication Adherence/statistics & numerical data , Organophosphonates/therapeutic use , Pre-Exposure Prophylaxis , Tenofovir/blood , Adenine/blood , Adult , Anti-HIV Agents/blood , Drug Therapy, Combination , Female , Humans , Interviews as Topic , Kenya , Male , Middle Aged , Predictive Value of Tests , Qualitative Research , Self Report , Tenofovir/therapeutic use , Treatment OutcomeABSTRACT
BACKGROUND: Safety of tenofovir disoproxil fumarate/emtricitabine (TDF-FTC) has been studied more extensively among HIV-infected patients than among HIV-uninfected people. Using data from a pre-exposure trial - FEM-PrEP -, we determined the cumulative probabilities of grade 1+ ALT, AST and creatinine and grade 2+ phosphorus toxicities; ALT/AST toxicities by baseline hepatitis B status; and change in mean creatinine, phosphorus, ALT and AST levels controlling for TDF-FTC adherence. METHODS AND FINDINGS: FEM-PrEP was a randomized, blinded, placebo-controlled trial of daily TDF-FTC among women in Africa. Enrolled women were in general good health, HIV antibody negative, 18 to 35 years old, hepatitis B surface antigen negative, and had normal hepatic and renal function at baseline. AST, ALT, phosphorus and serum creatinine were measured regularly throughout the trial. TDF-FTC concentrations were measured to assess adherence to TDF-FTC. The cumulative probabilities of grade 1+ creatininemia and grade 2+ phosphatemia toxicities were not statistically different between TDF-FTC and placebo arms. The cumulative probabilities of grade 1+ ALT and AST toxicities were higher among participants in the TDF-FTC arm than in the placebo arm (p = 0.03 for both). The proportions of grade 1+ and grade 2+ ALT or AST toxicities were significantly higher in participants who were hepatitis B virus surface antibody (HBsAb) positive than in those who were HBsAb-negative. Women with good adherence had higher mean change from baseline to week 4 in their AST levels (2.90 (0.37, 5.42); p = 0.025) than women with less than good adherence. CONCLUSIONS: We did not observe a significant relationship between randomization to TDF-FTC and creatinine or phosphorus toxicities. Women randomized to TDF-FTC had higher rates of mild to moderate ALT/AST toxicities, especially women with prior hepatitis B virus exposure. We also observed a significant increase in AST from baseline to week 4 among women who had higher adherence to TDF-FTC during that interval. TRIAL REGISTER: #NCT00625404, February 19, 2008.
Subject(s)
Adenine/analogs & derivatives , Anti-HIV Agents/adverse effects , Chemical and Drug Induced Liver Injury/etiology , Deoxycytidine/analogs & derivatives , Kidney Diseases/chemically induced , Organophosphonates/adverse effects , Reverse Transcriptase Inhibitors/adverse effects , Adenine/adverse effects , Adolescent , Adult , Alanine Transaminase/blood , Aspartate Aminotransferases/blood , Black People , Chemical and Drug Induced Liver Injury/blood , Creatinine/blood , Deoxycytidine/adverse effects , Double-Blind Method , Drug Therapy, Combination , Emtricitabine , Female , HIV Infections/prevention & control , Humans , Kidney Diseases/blood , Phosphorus/blood , Pre-Exposure Prophylaxis , Tenofovir , Young AdultABSTRACT
BACKGROUND: FEM-PrEP was unable to demonstrate the effectiveness of oral emtricitabine/tenofovir disoproxil fumarate (FTC/TDF) as pre-exposure prophylaxis for HIV prevention because of low adherence. We hypothesized that one reason for the poor adherence was low perceived HIV risk. METHODS: At enrollment and at quarterly follow-up visits, we assessed participants' perceived HIV risk for the subsequent 4 weeks. We used logistic regression to assess factors associated with some (small, moderate, or high) perceived HIV risk. We also used logistic regression with robust variance estimation to assess the association between risk perceptions (none versus some) reported at enrollment and at weeks 12, 24, and 36 and good adherence based on drug concentrations of plasma tenofovir and intracellular tenofovir diphosphate in specimens collected 4 weeks later (at weeks 4, 16, 28, and 40) among 150 randomly selected participants assigned FTC/TDF. RESULTS: Multiple factors were statistically associated with having some perceived risk, including having sex without a condom, having multiple partners, and not knowing if a partner has HIV. We observed a significant association between having some risk perception and good adherence (odds ratio: 2.0; 95% confidence interval: 1.1 to 3.5; P = 0.016). CONCLUSIONS: Data suggest that participants are likely knowledgeable about factors that increase their HIV risk. Perceived risk seemed to have influenced some participants' decisions to adhere to the study pill within the context of a placebo-controlled clinical trial. Future research can explore the role of risk perception in the uptake of and adherence to pre-exposure prophylaxis, now that FTC/TDF has been shown efficacious.
Subject(s)
Anti-Retroviral Agents/therapeutic use , Chemoprevention/methods , Disease Transmission, Infectious/prevention & control , HIV Infections/prevention & control , Health Knowledge, Attitudes, Practice , Medication Adherence , Adenine/analogs & derivatives , Adenine/therapeutic use , Adolescent , Adult , Blood Chemical Analysis , Deoxycytidine/analogs & derivatives , Deoxycytidine/therapeutic use , Emtricitabine , Female , HIV Infections/transmission , Humans , Organophosphonates/therapeutic use , Risk-Taking , Tenofovir , Young AdultABSTRACT
BACKGROUND: Several clinical trials have demonstrated the safety and effectiveness of oral tenofovir disoproxil fumarate (TDF), with or without emtricitabine (FTC), as pre-exposure prophylaxis (PrEP) for reducing the risk of HIV acquisition. Adherence to the study product was insufficient to demonstrate the effectiveness of FTC/TDF in 2 PrEP clinical trials conducted among women (FEM-PrEP and the Vaginal and Oral Interventions to Control the Epidemic study), but further analyses of adherence in these studies may inform PrEP demonstration projects and future HIV prevention clinical trials. METHODS: We randomly selected a subcohort of 150 participants randomized to FTC/TDF in 3 FEM-PrEP sites (Bondo, Kenya; Bloemfontein, South Africa; and Pretoria, South Africa) to examine adherence levels over time and to assess factors associated with adherence, based on plasma tenofovir and intracellular tenofovir diphosphate drug concentrations in specimens collected at 4-week visit intervals. RESULTS: We observed drug concentrations consistent with good adherence in 28.5% of all visit intervals when drug was available to use, but only 12% of participants achieved good adherence throughout their study participation. In multivariate analysis, the Bloemfontein site [odds ratio (OR): 2.43; 95% confidence interval (CI): 1.32 to 4.48] and liking the pill color (OR: 2.93; 95% CI: 1.18 to 7.27) were positively associated with good adherence, whereas using oral contraceptive pills at enrollment was negatively associated with good adherence (OR: 0.37; 95% CI: 0.18 to 0.74). CONCLUSIONS: Most participants did not regularly adhere to the study product throughout their trial participation, although a small minority did. Few factors associated with good adherence to the study product were identified in FEM-PrEP.
Subject(s)
Adenine/analogs & derivatives , Anti-HIV Agents/therapeutic use , Deoxycytidine/analogs & derivatives , HIV Infections/prevention & control , Medication Adherence/statistics & numerical data , Organophosphonates/therapeutic use , Adenine/administration & dosage , Adenine/blood , Adenine/therapeutic use , Administration, Oral , Adolescent , Adult , Anti-HIV Agents/administration & dosage , Deoxycytidine/administration & dosage , Deoxycytidine/therapeutic use , Emtricitabine , Female , Humans , Logistic Models , Male , Multivariate Analysis , Organophosphonates/administration & dosage , Organophosphonates/blood , Risk Factors , Tenofovir , Young AdultABSTRACT
BACKGROUND: Preexposure prophylaxis with antiretroviral drugs has been effective in the prevention of human immunodeficiency virus (HIV) infection in some trials but not in others. METHODS: In this randomized, double-blind, placebo-controlled trial, we assigned 2120 HIV-negative women in Kenya, South Africa, and Tanzania to receive either a combination of tenofovir disoproxil fumarate and emtricitabine (TDF-FTC) or placebo once daily. The primary objective was to assess the effectiveness of TDF-FTC in preventing HIV acquisition and to evaluate safety. RESULTS: HIV infections occurred in 33 women in the TDF-FTC group (incidence rate, 4.7 per 100 person-years) and in 35 in the placebo group (incidence rate, 5.0 per 100 person-years), for an estimated hazard ratio in the TDF-FTC group of 0.94 (95% confidence interval, 0.59 to 1.52; P=0.81). The proportions of women with nausea, vomiting, or elevated alanine aminotransferase levels were significantly higher in the TDF-FTC group (P=0.04, P<0.001, and P=0.03, respectively). Rates of drug discontinuation because of hepatic or renal abnormalities were higher in the TDF-FTC group (4.7%) than in the placebo group (3.0%, P=0.051). Less than 40% of the HIV-uninfected women in the TDF-FTC group had evidence of recent pill use at visits that were matched to the HIV-infection window for women with seroconversion. The study was stopped early, on April 18, 2011, because of lack of efficacy. CONCLUSIONS: Prophylaxis with TDF-FTC did not significantly reduce the rate of HIV infection and was associated with increased rates of side effects, as compared with placebo. Despite substantial counseling efforts, drug adherence appeared to be low. (Supported by the U.S. Agency for International Development and others; FEM-PrEP ClinicalTrials.gov number, NCT00625404.).