Multicenter Evaluation of the Xpert MRSA NxG Assay for Detection of Methicillin-Resistant Staphylococcus aureus in Nasal Swabs.

Health care-associated methicillin-resistant Staphylococcus aureus (MRSA) infections are a burden on the health care system. Clinical laboratories play a key role in reducing this burden, as the timely identification of MRSA colonization or infection facilitates infection control practices that are effective at limiting invasive MRSA infections. The Xpert MRSA NxG assay recently received FDA clearance for the direct detection of MRSA from nasal swabs. This multicenter study evaluated the clinical performance characteristics of the Xpert MRSA NxG assay with prospectively collected rayon nasal swabs (n = 1,103) and flocked swab (ESwab) nasal specimens (n = 846). Culture-based identification methods and antimicrobial susceptibility testing were used as the reference standards for comparison. According to the reference method, the positivity rates for MRSA in the population evaluated were 11.1% (122/1,103) for rayon swabs and 11.6% (98/846) for flocked swabs. The overall sensitivity and specificity of the rayon swabs were 91.0% (95% confidence interval [CI], 84.6 to 94.9%) and 96.9% (95% CI, 95.7 to 97.8%), respectively, across eight testing sites. The flocked swab specimens were 92.9% sensitive (95% CI, 86.0 to 96.5%) and 97.6% specific (95% CI, 96.2 to 98.5%) for MRSA detection across six testing sites. The sensitivity and specificity of the combined flocked and rayon swab data were 91.8% (95% CI, 87.4 to 94.8%) and 97.2% (95% CI, 96.3 to 97.9%), respectively. The positive predictive value (PPV) for rayon swabs was 78.7%, versus 83.5% for ESwabs. The negative predictive values (NPVs) for rayon swabs and ESwab specimens were 98.9% and 99.1%, respectively. In conclusion, the Xpert MRSA NxG assay is a sensitive and specific assay for the direct detection of MRSA from nasal swab specimens.

Efficacy and safety of crofelemer for noninfectious diarrhea in HIV-seropositive individuals (ADVENT trial): a randomized, double-blind, placebo-controlled, two-stage study.

BACKGROUND: HIV-associated diarrhea remains a significant concern with limited treatment options. OBJECTIVE: To determine the optimal dose, efficacy, and safety of crofelemer for noninfectious diarrhea. METHODS: This randomized, double-blind, phase 3 trial used a 2-stage design. Both stages included 2-week screening, 4-week placebo-controlled treatment, and 20-week placebo-free (open-label) extension phases. In stage I, 196 HIV-seropositive patients with chronic diarrhea were randomized to crofelemer 125 mg, 250 mg, or 500 mg or placebo twice daily. Using a prospective analysis, the 125-mg twice-daily dose was selected for stage II. In stage II, 180 new patients were randomized to crofelemer 125 mg twice daily or placebo for 4 weeks. Primary efficacy analysis was the percentage of patients (stages I/II combined) who achieved clinical response (defined as ≤2 watery stools/week during ≥2 of 4 weeks). During the placebo-free extension phase, response (≤2 watery stools) was assessed weekly. RESULTS: Significantly more patients receiving crofelemer 125 mg achieved clinical response versus placebo (17.6% vs 8.0%; one-sided, P = .01). Crofelemer 125 mg resulted in a greater change from baseline in number of daily watery bowel movements (P = .04) and daily stool consistency score (P = .02) versus placebo. During the placebo-free extension phase, percentages of weekly responders ranged from 40% to 56% at weeks 11 to 24. Crofelemer was minimally absorbed, well tolerated, did not negatively impact clinical immune parameters, and had a safety profile comparable to placebo. CONCLUSIONS: In HIV-seropositive patients taking stable antiretroviral therapy, crofelemer provided significant improvement in diarrhea with a favorable safety profile.

Injectable poly-L-lactic acid for human immunodeficiency virus-associated facial lipoatrophy: cumulative year 2 interim analysis of an open-label study (FACES).

BACKGROUND: Studies of injectable poly-L-lactic acid (PLLA) in human immunodeficiency virus (HIV)-associated facial lipoatrophy have predominantly included male Caucasians. OBJECTIVE: To report cumulative year 2 interim study results examining the safety and efficacy of injectable PLLA in subjects with HIV categorized according to Fitzpatrick skin type and sex. MATERIALS AND METHODS: This is an ongoing open-label, multicenter, 5-year study of 290 treated subjects. After correction with injectable PLLA, subjects are being followed annually. Primary end points include incidence and severity of treatment-emergent adverse events (TEAEs). Secondary end points include mean change from baseline of James scale severity grade and treatment satisfaction. RESULTS: At 2 years, TEAE incidences were: potentially related to study product (n = 53,18.3%) or injection procedure (n = 71, 24.5%), injection-site nodules (n = 24, 8.3%) and papules (n = 25, 8.6%). No hypertrophic scars, keloids, or product-related serious TEAEs were reported. Mean improvement in James scale grade for all groups was 1.4 (p < .001), and 89.4% of subjects and 95.5% of physicians rated treatment satisfaction as very good or excellent. CONCLUSION: At 2 years, injectable PLLA is a safe and effective long-term treatment for HIV-associated facial lipoatrophy regardless of Fitzpatrick skin type; confirmation of these results will be needed at the completion of this 5-year study.

Similar virologic and immunologic efficacy with fosamprenavir boosted with 100 mg or 200 mg of ritonavir in HIV-infected patients: results of the LESS trial.

PURPOSE: ritonavir (RTV) effectively boosts most protease inhibitors but is associated with significant dose-dependent adverse events (AEs). In an effort to better manage toxicities through a reduced dose of RTV, this study compared fosamprenavir (FPV) boosted with RTV 100 mg (FPV/r100) or with RTV 200 mg (FPV/r200) daily. METHODS: this 24-week, open-label study enrolled patients taking a FPV/r 200-containing regimen who had HIV RNA <400 copies/mL and randomized them 1:2 to continue that regimen or simplify to FPV/r100 once daily. Other medications were not altered. The primary endpoint was the percentage of patients without suspected or confirmed virologic failure (HIV RNA ≥ 400 copies/mL) through week 24 by a missing/discontinuation equals failure (M/D=F) analysis. Noninferiority criteria were demonstrated if the lower bound of the 95% confidence interval (CI) for the difference in the primary endpoint rates between groups was greater than -12. RESULTS: the 2 regimens met prespecified noninferiority criteria (FPV/r100, 92%; FPV/r 200, 94%; 95% CI, -9.36 to 5.12). At week 24, the percentage of patients with HIV RNA <50 copies/mL by M/ D=F was 83% in the FPV/r100 group and 85% in the FPV/r 200 group. Drug-related grade 2-4 AEs were uncommon (FPV/r100, 4%; FPV/r 200, 7%). Median changes in lipids were similar in both groups, with the exception of triglycerides (FPV/r100, -21 mg/dL; FPV/r 200, -2 mg/dL). CONCLUSIONS: this 24-week study demonstrated that among previously suppressed patients, once-daily FPV/r100 was similar to FPV/r 200 in virologic and immunologic effects but was associated with greater decreases from baseline in triglyceride levels.

A randomized, controlled trial of initial anti-retroviral therapy with abacavir/lamivudine/zidovudine twice-daily compared to atazanavir once-daily with lamivudine/zidovudine twice-daily in HIV-infected patients over 48 weeks (ESS100327, the ACTION Study).

BACKGROUND: Traditional first line regimens containing a non-nucleoside reverse transcriptase inhibitor or protease inhibitor may not be suitable for a subset of antiretroviral-naïve patients such as those with certain co-morbidities, women of child-bearing potential, and intolerability to components of standard first line therapy. This study was conducted to determine if alternate treatment options may meet the needs of both general and special patient populations. The ACTION study was a randomized, open-label, multicenter, 48-week trial that compared the safety and efficacy of a triple nucleoside regimen versus a protease inhibitor plus a dual nucleoside regimen in HIV-1 treatment-naïve subjects. RESULTS: 279 HIV-infected subjects with HIV-1 RNA (VL) >5000 but < 200,000 copies/mL (c/mL) and CD4+ count >/= 100 cells/mm3 were randomized (1:1) to receive abacavir sulfate/lamivudine/zidovudine (ABC/3TC/ZDV) twice-daily or atazanavir (ATV) once-daily plus lamivudine/zidovudine (3TC/ZDV) twice-daily. Protocol-defined virologic failure was based on multiple failure criteria.Non-inferiority of ABC/3TC/ZDV to ATV+3TC/ZDV was established with 62% vs. 59% of subjects achieving a VL < 50 c/mL at week 48, [ITT(E), M/S = F, 95% CI: -5.9, 10.4]. Similar results were observed in the 230 (82%) subjects with baseline VL<100,000 c/mL (ABC/3TC/ZDV vs. ATV+3TC/ZDV), 66% vs. 59%; 95% CI: -5.6, 19.5. However, ABC/3TC/ZDV did not meet the non-inferiority criterion compared to ATV+3TC/ZDV in the 48 subjects with baseline VL >/= 100,000 c/mL, 39% vs. 60%; 95% CI: -49.2, 7.4, respectively. Protocol-defined virologic failure was similar between groups. CONCLUSION: ABC/3TC/ZDV demonstrated comparable virologic efficacy to ATV+3TC/ZDV in this population over 48 weeks. In those with a baseline VL >/= 100,000 c/mL, subjects in the ATV+3TC/ZDV showed better virologic efficacy. Both regimens offer benefits in select therapy-naïve subjects. TRIAL REGISTRATION: [Clinical Trials Identifier, NCT00082394].

Natural history of anemia associated with interferon/ribavirin therapy for patients with HIV/HCV coinfection.

The natural history of anemia related to interferon/ribavirin (IFN/RBV) treatment in patients with human immunodeficiency virus/hepatitis C virus (HIV/HCV) coinfection is not completely understood. The current 8-week, multicenter, observational study characterized anemia over the course of HCV treatment in patients with HIV/HCV coinfection. Eligible HIV/HCV coinfected patients were receiving care in community-based and academic institutions and were on stable antiretroviral therapy and initiating IFN/RBV therapy. Hb, sEPO, reticulocytes, transfusions, laboratory values (e.g., total bilirubin), and IFN and RBV dosages were monitored weekly. Ninety-one patients were analyzed (mean age, 46 years; 71% on HAART) and 53 patients completed the study. Mean Hb decreased significantly (5.0 g/dl) within 1 week of initiating IFN/RBV therapy (p = 0.0002); Hb nadir occurred at a median of 37 days. Maximum Hb decreases of > or =2.0 g/dl occurred in 56 (62%) patients and > or =3.0 g/dl occurred in 45 (49%) patients. Reticulocyte count increased within the first 2 weeks and sEPO peaked at week 3. Mean increase from baseline to week 2 in reticulocyte count and sEPO, respectively, was 1.3% (n = 74) and 45.0 mIU/ml (n = 80) (p < 0.0001 for each parameter), and from baseline to week 8 was 0.9% (n = 48) and 41.0 mIU/ml (n = 52) (p < or = 0.0001 for each parameter). Adverse events (AEs) were the most common reason for study discontinuation (66% of discontinuing patients). Among the 25 patients who discontinued due to AEs, 84% discontinued due to anemia (n = 21). Significant decreases in Hb were observed in HIV/HCV-coinfected patients within 1 week of initiating IFN/RBV therapy. sEPO and reticulocyte increases were blunted in response to anemia; Hb levels did not return to baseline values and anemia was a frequent reason for discontinuing the study.

Evaluation of oral serum-derived bovine immunoglobulins in HIV-infected patients with chronic idiopathic diarrhea.

Objectives To evaluate serum-derived bovine immunoglobulin/protein isolate (SBI) for safety and impact on gastrointestinal (GI) symptoms in HIV patients with chronic idiopathic diarrhea. Methods A multi-center trial comprised of a double-blind, placebo (PBO)-controlled lead-in phase, (participants received PBO or SBI at 2.5 or 5.0 g BID for 4 weeks) followed by a 20-week, PBO-free phase (SBI at either 2.5 or 5.0 g BID). Participants included HIV-infected patients who were virologically suppressed with a history of chronic idiopathic diarrhea, defined as > 3 loose stools per day for ≥ 3 months without an identifiable cause. Safety was evaluated by monitoring adverse events (AEs) and clinical laboratory testing. Health status and changes in GI symptoms were assessed using validated questionnaires. Results SBI was well tolerated by the 103 participants with only 2 withdrawals due to AEs potentially associated with SBI. Mean number of daily unformed stools decreased from about 4 at baseline to less than 2 by week 4 for all study groups. Improvements in several other GI symptoms were also reported. Comparison of the PBO group to SBI groups showed no significant differences, although both SBI cohorts reported significantly improved health status scores. GI symptom improvements were maintained throughout the 20-week PBO-free phase. Conclusions Oral SBI is safe and well tolerated at the doses studied in HIV patients with chronic diarrhea. No conclusions could be drawn regarding impact on GI symptoms. Additional studies are ongoing to examine the biological and immunologic effects of SBI in virologically suppressed HIV-infected patients.

Switching from efavirenz, emtricitabine, and tenofovir disoproxil fumarate to tenofovir alafenamide coformulated with rilpivirine and emtricitabine in virally suppressed adults with HIV-1 infection: a randomised, double-blind, multicentre, phase 3b, non-inferiority study.

BACKGROUND: Tenofovir alafenamide is a prodrug that reduces tenofovir plasma concentrations by 90% compared with tenofovir disoproxil fumarate, thereby decreasing bone and renal risks. The coformulation of rilpivirine, emtricitabine, and tenofovir alafenamide has recently been approved, and we aimed to investigate the efficacy, safety, and tolerability of switching to this regimen compared with remaining on coformulated efavirenz, emtricitabine, and tenofovir disoproxil fumarate. METHODS: In this randomised, double-blind, placebo-controlled, non-inferiority trial, HIV-1-infected adults were enrolled at 120 hospitals and outpatient clinics in eight countries in North America and Europe. Participants were virally suppressed (HIV-1 RNA <50 copies per mL) on efavirenz, emtricitabine, and tenofovir disoproxil fumarate for at least 6 months before enrolment and had creatinine clearance of at least 50 mL/min. Participants were randomly assigned (1:1) to receive a single-tablet regimen of rilpivirine (25 mg), emtricitabine (200 mg), and tenofovir alafenamide (25 mg) or to continue a single-tablet regimen of efavirenz (600 mg), emtricitabine (200 mg), and tenofovir disoproxil fumarate (300 mg), with matching placebo. Investigators, participants, study staff, and those assessing outcomes were masked to treatment group. The primary endpoint was the proportion of participants with plasma HIV-1 RNA of less than 50 copies per mL at week 48 (assessed by the US Food and Drug Administration snapshot algorithm), with a prespecified non-inferiority margin of 8%. This study was registered with ClinicalTrials.gov, number NCT02345226. FINDINGS: Between Jan 26, 2015, and Aug 27, 2015, 875 participants were randomly assigned and treated (438 with rilpivirine, emtricitabine, and tenofovir alafenamide and 437 with efavirenz, emtricitabine, tenofovir disoproxil fumarate). Viral suppression at week 48 was maintained in 394 (90%) of 438 participants assigned to the tenofovir alafenamide regimen and 402 (92%) of 437 assigned to the tenofovir disoproxil fumarate regimen (difference -2·0%, 95·001% CI -5·9 to 1·8), demonstrating non-inferiority. 56 (13%) of 438 in participants in the rilpivirine, emtricitabine, and tenofovir alafenamide group experienced treatment-related adverse events compared with 45 (10%) of 437 in the efavirenz, emtricitabine, and tenofovir disoproxil fumarate group. INTERPRETATION: Switching to rilpivirine, emtricitabine, and tenofovir alafenamide from efavirenz, emtricitabine, and tenofovir disoproxil fumarate was non-inferior in maintaining viral suppression and was well tolerated at 48 weeks. These findings support guidelines recommending tenofovir alafenamide-based regimens, including coformulation with rilpivirine and emtricitabine, as initial and ongoing treatment for HIV-1 infection. FUNDING: Gilead Sciences.

Switching from tenofovir disoproxil fumarate to tenofovir alafenamide coformulated with rilpivirine and emtricitabine in virally suppressed adults with HIV-1 infection: a randomised, double-blind, multicentre, phase 3b, non-inferiority study.

BACKGROUND: Tenofovir alafenamide, a tenofovir prodrug, results in 90% lower tenofovir plasma concentrations than does tenofovir disproxil fumarate, thereby minimising bone and renal risks. We investigated the efficacy, safety, and tolerability of switching to a single-tablet regimen containing rilpivirine, emtricitabine, and tenofovir alafenamide compared with remaining on rilpivirine, emtricitabine, and tenofovir disoproxil fumarate. METHODS: In this randomised, double-blind, multicentre, placebo-controlled, non-inferiority trial, HIV-1-infected adults were screened and enrolled at 119 hospitals in 11 countries in North America and Europe. Participants were virally suppressed (HIV-1 RNA <50 copies per mL) on rilpivirine, emtricitabine, and tenofovir disoproxil fumarate for at least 6 months before enrolment and had creatinine clearance of at least 50 mL/min. Participants were randomly assigned (1:1) to receive a single-tablet regimen of either rilpivirine (25 mg), emtricitabine (200 mg), and tenofovir alafenamide (25 mg) or to remain on a single-tablet regimen of rilpivirine (25 mg), emtricitabine (200 mg), and tenofovir disoproxil fumarate (300 mg), with matching placebo, once daily for 96 weeks. Investigators, participants, study staff, and those assessing outcomes were masked to treatment group. All participants who received one dose of study drug and were on the tenofovir disoproxil fumarate regimen before screening were included in primary efficacy analyses. The primary endpoint was the proportion of participants with less than 50 copies per mL of plasma HIV-1 RNA at week 48 (by the US Food and Drug Administration snapshot algorithm), with a prespecified non-inferiority margin of 8%. This study was registered with ClinicalTrials.gov, number NCT01815736. FINDINGS: Between Jan 26, 2015, and Aug 25, 2015, 630 participants were randomised (316 to the tenofovir alafenamide group and 314 to the tenofovir disoproxil fumarate group). At week 48, 296 (94%) of 316 participants on tenofovir alafenamide and 294 (94%) of 313 on tenofovir disoproxil fumarate had maintained less than 50 copies per mL HIV-1 RNA (difference -0·3%, 95·001% CI -4·2 to 3·7), showing non-inferiority of tenofovir alafenamide to tenofovir disoproxil fumarate. Numbers of adverse events were similar between groups. 20 (6%) of 316 participants had study-drug related adverse events in the tenofovir alafenamide group compared with 37 (12%) of 314 in the tenofovir disoproxil fumarate group; none of these were serious. INTERPRETATION: Switching to rilpivirine, emtricitabine, and tenofovir alafenamide was non-inferior to continuing rilpivirine, emtricitabine, tenofovir disoproxil fumarate in maintaining viral suppression and was well tolerated at 48 weeks. These findings support guidelines recommending tenofovir alafenamide-based regimens, including coformulation with rilpivirine and emtricitabine, as initial and ongoing treatment for HIV-1 infection. FUNDING: Gilead Sciences.

A randomized study of emtricitabine and lamivudine in stably suppressed patients with HIV.

BACKGROUND: Once daily (QD) dosing facilitates regimen simplification and adherence to antiretroviral therapy. Emtricitabine (FTC) QD is a newly approved nucleoside reverse transcriptase inhibitor compared in this study to twice daily lamivudine (3TC BID). METHODS: Controlled, open label equivalence trial of 440 HIV-1-infected patients with plasma HIV-1 RNA stably suppressed on a regimen of 3TC 150 mg BID, stavudine or zidovudine, and a protease inhibitor or non-nucleoside reverse transcriptase inhibitor. Patients were randomized to continue their current regimen or replace 3TC with FTC 200 mg QD. If HIV-1 RNA levels were

HIV-1 transmission patterns in antiretroviral therapy-naïve, HIV-infected North Americans based on phylogenetic analysis by population level and ultra-deep DNA sequencing.

Factors that contribute to the transmission of human immunodeficiency virus type 1 (HIV-1), especially drug-resistant HIV-1 variants remain a significant public health concern. In-depth phylogenetic analyses of viral sequences obtained in the screening phase from antiretroviral-naïve HIV-infected patients seeking enrollment in EPZ108859, a large open-label study in the USA, Canada and Puerto Rico (ClinicalTrials.gov NCT00440947) were examined for insights into the roles of drug resistance and epidemiological factors that could impact disease dissemination. Viral transmission clusters (VTCs) were initially predicted from a phylogenetic analysis of population level HIV-1 pol sequences obtained from 690 antiretroviral-naïve subjects in 2007. Subsequently, the predicted VTCs were tested for robustness by ultra deep sequencing (UDS) using pyrosequencing technology and further phylogenetic analyses. The demographic characteristics of clustered and non-clustered subjects were then compared. From 690 subjects, 69 were assigned to 1 of 30 VTCs, each containing 2 to 5 subjects. Race composition of VTCs were significantly more likely to be white (72% vs. 60%; p = 0.04). VTCs had fewer reverse transcriptase and major PI resistance mutations (9% vs. 24%; p = 0.002) than non-clustered sequences. Both men-who-have-sex-with-men (MSM) (68% vs. 48%; p = 0.001) and Canadians (29% vs. 14%; p = 0.03) were significantly more frequent in VTCs than non-clustered sequences. Of the 515 subjects who initiated antiretroviral therapy, 33 experienced confirmed virologic failure through 144 weeks while only 3/33 were from VTCs. Fewer VTCs subjects (as compared to those with non-clustering virus) had HIV-1 with resistance-associated mutations or experienced virologic failure during the course of the study. Our analysis shows specific geographical and drug resistance trends that correlate well with transmission clusters defined by HIV sequences of similarity. Furthermore, our study demonstrates the utility of molecular and epidemiological analysis of VTCs for identifying population-specific risks associated with HIV-1 transmission and developing effective local healthcare strategies.

Efficacy and safety of once daily elvitegravir versus twice daily raltegravir in treatment-experienced patients with HIV-1 receiving a ritonavir-boosted protease inhibitor: randomised, double-blind, phase 3, non-inferiority study.

BACKGROUND: Elvitegravir is a once daily inhibitor of HIV-1 integrase boosted by ritonavir. We aimed to compare the efficacy and safety of elvitegravir with raltegravir, another HIV-1 integrase inhibitor, in patients in whom previous antiretroviral treatment failed. METHODS: We conducted a randomised, double-blind, double-dummy, phase 3 study at 234 sites in 13 countries. Eligible patients had plasma HIV RNA of 1000 copies per mL or greater, any CD4 cell count, and resistance to or 6 months' experience with at least two classes of antiretroviral drugs. They received an open-label background regimen of a fully active, ritonavir-boosted protease inhibitor and a second agent. We randomly allocated patients (1:1) by computer with a block size of four to receive either elvitegravir 150 mg once daily (n=361; 85 mg dose if given with atazanavir, or lopinavir with ritonavir) or raltegravir 400 mg twice daily (n=363). Placebo tablets were given to mask the difference in daily dosing. The primary endpoint was achievement and maintenance of virological response (HIV RNA <50 copies per mL) through week 48. Non-inferiority was prespecified with a margin of 10%. We did a modified intention-to-treat analysis. This study is registered with ClinicalTrials.gov, number NCT00708162. FINDINGS: Ten patients allocated elvitegravir and 12 assigned raltegravir were excluded from the analysis (either for protocol violations or because they did not receive treatment). 207 (59%) of 351 patients allocated elvitegravir achieved virological response compared with 203 (58%) of 351 assigned raltegravir (treatment difference 1·1%, 95% CI -6·0 to 8·2), meeting the criterion for non-inferiority (p=0·001). Three patients allocated elvitegravir had serious adverse events related to study drugs compared with seven assigned raltegravir; two and eight patients died, respectively. More individuals assigned elvitegravir reported diarrhoea up to week 48 (p=0·023), and more patients assigned raltegravir had grade 3 or 4 rises in alanine aminotransferase (p=0·020) or aspartate aminotransferase (p=0·009). INTERPRETATION: Elvitegravir used in combination with a ritonavir-boosted protease inhibitor in treatment-experienced patients has similar efficacy and safety to raltegravir. Since elvitegravir can be given once a day compared with twice a day for raltegravir, elvitegravir might improve patients' adherence. FUNDING: Gilead Sciences.

Efficacy and safety of a once-daily fixed-dose combination of abacavir/lamivudine compared with abacavir twice daily and lamivudine once daily as separate entities in antiretroviral-experienced HIV-1-infected patients (CAL30001 Study).

BACKGROUND: A one-tablet, once-daily abacavir/lamivudine fixed-dose combination (FDC) has been recently approved to treat HIV-1 infection. METHODS: A randomized, open-label, parallel-group, multicenter study to compare the efficacy and safety of the FDC group to the separate entities (SE) group, in combination with tenofovir and a new protease inhibitor or nonnucleoside reverse transcription inhibitor in antiretroviral-experienced adults experiencing virologic failure (VF). Eligible subjects had viral loads >1000 copies/mL with < or =3 nucleoside reverse transcription inhibitor-associated mutations. The primary efficacy end point was time-average changed from baseline (average area under the curve minus baseline) in plasma HIV-1 RNA over 48 weeks. RESULTS: A total of 186 subjects were enrolled. The average area under the curve minus baseline was -1.65 and -1.83 log10 copies/mL in the FDC and SE groups, respectively (intention to treat; 95% confidence interval: -0.13, 0.38). Patients in the FDC (50%) and SE groups (47%) achieved viral loads <50 copies/mL based on the time to loss of virologic response algorithm. VF was low and similar in both groups (FDC, 16%; SE, 18%). Tolerability was similar between the 2 groups. CONCLUSIONS: The FDC group had noninferior efficacy over 48 weeks to the SE group in treatment-experienced subjects with VF.