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To characterize how community mobility patterns across the United States correlate with local changes in retina visits during the pandemic.Outpatient retina clinic visits were linked to population mobility by combining multiple public data sets, including the Google Community Mobility Reports and data from the Centers for Disease Control and Infection. Percentage change from baseline in daily-average number of retina visits by county and mobility were measured by county.A total of 2,159,689 patient visits were examined across 332 counties. Daily-average retina visits decreased by 7.0%, 19.0%, 5.0%, and 4.0% from Quarter 1 to 4 of 2020. This decrease was negatively correlated with increased incident of COVID-19 deaths for Quarters 1 to 3 (r = -0.13, r = -0.16, and r = -0.15, respectively, P0.001) and increased incident cases for Quarters 1 and 2 (r = -0.18, r = -0.13, respectively, P0.001). Daily-average retina visits relative to baseline were significantly lower for metropolitan counties in Quarters 1 and 2, compared with urban and rural (P0.001). The decline in retina visits had greatest association with decline in workplace visits in Quarters 1 to 3 (r = 0.27, r = 0.09, r = 0.12, respectively, P0.001 for all).This study provides insight into how regional mobility patterns may help to explain and predict patient behaviors and retina outpatient visit responses during the COVID-19 pandemic.

To evaluate seasonal and environmental variations on the incidence and outcomes of postinjection endophthalmitis.A single-center, retrospective cohort study was conducted including all patients diagnosed with post-injection endophthalmitis between 2013-2018. Associations between climate variables and endophthalmitis incidence were evaluated.Of 423,297 injections administered, seasonal distribution in spring, summer, autumn, and winter was 26%, 27%, 25%, and 22%, respectively. Of 171 cases of endophthalmitis identified, seasonal distribution over the spring, summer, autumn, and fall was 25%, 23%, 26%, and 26%, respectively. Endophthalmitis incidence was not correlated with monthly precipitation (In contrast to previous work on postcataract endophthalmitis, seasonal and weather factors were not associated with post-injection endophthalmitis risk or bacterial species isolated. Visual outcomes at initial endophthalmitis presentation were correlated with precipitation, and worse visual outcomes were seen in patients who developed endophthalmitis in the spring.

The US federal government uses health provider shortage areas (HPSAs) to define patient accessibility to primary care physicians. It is unclear whether HPSAs can be applied to eye care providers (ECP). Our study determined the applicability of federal HPSA designations to ECP availability in the U.S.Cross-sectional study SUBJECTS: United States (US) general population and ophthalmologists/optometrists in the Medicare database.The primary care HPSA score, visual impairment prevalence, and ECP location were determined for each census tract or county using data from the US Department of Health and Human Services (DHHS), the Centers for Disease Control and Prevention (CDC), and Centers for MedicareMedicaid Services (CMS).Association of HPSA with vision loss and ECP density was examined. The two-step floating catchment area (2SFCA) approach was used to newly define eye care shortage areas [patient accessibility score (PAS), higher being worse accessibility)] for every county in the US, by weighting the 2SFCA scores by prevalence of vision loss and ECP density. Multivariable logistic regression was used to identify sociodemographic variables associated with areas of ECP shortage.Among 72,735 census tracts included, there were statistically significant but weak correlations of HPSA score with visual impairment (VI) (r=0.38, p0.0001) and ECP density per county population (r=-0.18, p0.0001). Only 54.0% of census tracts with25Current HPSAs only weakly correlate with ECP supply. We propose a new approach to identify counties with high need but limited access to eye care.

7509 Background: ADI-001 is a first-in-class allogeneic gamma delta (γδ) CAR T-cell therapy targeting the B-cell antigen CD20. ADI-001 also has both adaptive and innate cytotoxic effector functions to complement CAR targeting, potentially enhancing efficacy and reducing the possibility of tumor escape due to antigen loss. ADI-001 expresses MHC independent γδ T cell receptors, thus lowering the risk of graft versus host disease (GvHD) without the need for gene-editing. Methods: This phase 1 trial evaluates ADI-001 in adults with relapsed/refractory advanced B-cell lymphoma. Eligibility criteria included presence of measurable lesions, expression of CD20 and ≥ 2 prior systemic therapies. All patients received conditioning therapy with fludarabine and cyclophosphamide. ADI-001 is administered at 3 flat dose levels (DL; DL1:3E7, DL2:1E8, or DL3:3E8 cells) in a 3 + 3 dose-escalation scheme. Dose-limiting toxicities (DLT) were monitored during the initial 28-days post-treatment. Patients who completed the 28-day DLT period were considered evaluable. Treatment-emergent adverse events were graded by CTCAE v5.0, and immune effector cell toxicity assessment and grading were performed per ASTCT criteria. Objective response rates (ORR) were evaluated by independent radiographic review per Lugano 2014 criteria. Results: As of 14 February 2022, eight patients were enrolled and six were evaluable. Of these six patients, 2/6 were female (33%) and the median age was 62 years (range 45-75). The median number of prior therapies was 3.5 (range 2-5) and median IPI score was 3.5 (range 2-4). One patient received prior anti-CD19 CAR T cells therapy with lisocabtagene maraleucel. There were five patients with large B-cell lymphoma and one with mantle cell lymphoma. Among the six evaluable patients, three were treated on DL1 and three on DL2. Most related AEs (78%) were of grade 1/2. There were three AESI: two CRS (one grade 1 and one grade 2) and one grade 1 ICANS, and the only related SAEs were the grade 2 CRS and grade 1 ICANS. There was no reported GvHD and no protocol defined DLT events. At day 28, the ORR based upon PET/CT was 67% (4/6 patients) and the CR rate was 67% (4/6 patients). Both patients with ≥ 3 months post-treatment follow-up remained in CR. Additional data will be presented at the meeting. Conclusions: ADI-001 γδ CAR T cells were well tolerated, with a favorable safety profile and encouraging preliminary efficacy. Patients who achieved CR at day 28 appeared to be disease free during further follow-up at month-3. Clinical trial information: NCT04735471.

Audrey L Shaw,1 David W Mathews,1 John E Hinkle,2 Bryon W Petschow,1 Eric M Weaver,3 Christopher J Detzel,1 Gerald L Klein,4 Timothy P Bradshaw1 1Clinical Development, Entera Health, Inc., 2Life Sciences Consulting and Analytics, EarlyPhase Sciences, Inc., Cary, 3Executive Management, Prairie Pharms, LLC, Nora Springs, 4Executive Management, MedSurgPI, LLC, Raleigh, NC, USA Purpose: Previous studies have shown that oral administration of bovine immunoglobulin protein preparations is safe and provides nutritional and intestinal health benefits. The purpose of this study was to evaluate the plasma amino acid response following a single dose of serum-derived bovine immunoglobulin/protein isolate (SBI) and whether bovine immunoglobulin G (IgG) is present in stool or in blood following multiple doses of SBI in healthy volunteers.Methods: A total of 42 healthy adults were administered a single dose of placebo or SBI at one of three doses (5 g, 10 g, or 20 g) in blinded fashion and then continued on SBI (2.5 g, 5 g, or 10 g) twice daily (BID) for an additional 2weeks. Serial blood samples were collected for amino acid analysis following a single dose of placebo or SBI. Stool and blood samples were collected to assess bovine IgG levels.Results: The area under the curve from time 0minute to 180 minutes for essential and total amino acids as well as tryptophan increased following ingestion of 5g, 10g, or 20g of SBI, with a significant difference between placebo and all doses of SBI (p

© 2017 Informa UK Limited, trading as Taylor & Francis Group. 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.

Background: Systemic inflammation persists in chronic HIV infection and is associated with increased rates of non-AIDS events such as cardiovascular and liver disease. Increased gut permeability and systemic exposure to microbial products are key drivers of this inflammation. Serum-derived bovine immunoglobulin/protein isolate (SBI) supports gut healing in other conditions such as inflammatory bowel disease. Methods: In this randomized, double-blind study, participants receiving suppressive antiretroviral therapy (ART) with chronic diarrhea received placebo or SBI at 2.5 g BID or 5 g BID for 4 weeks, followed by a 20-week placebo-free extension phase with SBI at either 2.5 or 5 g BID. Intestinal fatty acid binding protein (I-FABP), zonulin, flagellin, lipopolysaccharide (LPS) and LPS-binding protein, and inflammatory markers were measured by ELISA or multiplex assays. Non-parametric tests were used for analysis. Results: One hundred three participants completed the study. By week 24 SBI significantly decreased circulating levels of I-FABP (-0.35 ng/mL, P = 0.002) and zonulin (-4.90 ng/mL, P = 0.003), suggesting improvement in gut damage, and interleukin-6 (IL-6) (-0.40 pg/mL, P = 0.002), reflecting improvement in systemic inflammation. In participants with the lowest quartile of CD4+ T-cell counts at baseline (189-418 cells/mL), CD4+ T-cell counts increased significantly (26 cells/mL; P = 0.002). Conclusions: Oral SBI may decrease inflammation and warrants further exploration as a potential strategy to improve gut integrity and decrease systemic inflammation among persons receiving prolonged suppressive ART. Keywords: HIV infection; CD4 T cell; Serum bovine immunoglobulin protein; Interleukin; Inflammation; Intestine; I-FABP

Objective: Elvitegravir (EVG) is in phase 3 development in combination with ritonavir (RTV)-boosted protease inhibitors in treatment-experienced, HIV-infected patients. Two studies evaluated pharmacokinetic (PK) interactions among EVG and RTV-boosted tipranavir (TPV/r) or darunavir (DRV/r). Methods: Healthy volunteers received EVG/r alone (study 1: 200/100 mg once daily; study 2: 125/100 mg once daily), TPV/r (500/200 mg twice daily) or DRV/r (600/100 mg twice daily) alone, and EVG (200 or 125 mg as applicable) added to TPV/r (500/200 mg twice daily) or DRV/r (600/100 mg twice daily) in a randomized crossover design, with assessment of steady-state PK for EVG, TPV, DRV, and RTV. Safety was assessed by clinical monitoring. Studies were powered to conclude lack of an interaction if the 90% confidence interval for the geometric mean ratios of the AUCtau and Cmax for EVG, TPV, and DRV were within predefined no-effect boundaries. Trough concentrations were also assessed. Results: No subjects discontinued for adverse events during treatment with EVG/r alone. On coadministration, AUCtau and Cmax of EVG and TPV and EVG and DRV were within prespecified no-effect boundaries versus treatment alone; trough concentrations were also not substantially altered. Conclusions: The PK of EVG and TPV or DRV were not altered after coadministration of EVG with TPV/r or DRV/r. EVG PK was similar with varied RTV doses of 100 mg once daily, 100 mg twice daily, or 200 mg twice daily. EVG can be added to TPV/r or DRV/r regimens without dose adjustment.

OBJECTIVES. The purpose of this work was to obtain long-term safety and efficacy data for antiretroviral regimens containing emtricitabine in HIV-infected pediatric subjects and confirm that a pediatric dose of 6 mg/kg once daily would provide steady-state emtricitabine concentrations comparable to those observed in adults given 200 mg of emtricitabine once daily.PATIENTS AND METHODS. HIV-infected subjects between 3 months and 16 years of age were enrolled, including 71 antiretroviral-naïve subjects and 45 antiretroviral-experienced subjects. Naive subjects received emtricitabine plus stavudine plus lopinavir or ritonavir. Experienced subjects replaced the lamivudine in their existing regimens with emtricitabine. Tolerance, safety, disease progression, and virologic and immunologic responses were evaluated.RESULTS. The Kaplan-Meier probability of persistent virologic response in the intent-to-treat population through week 164 at ≤400 copies per mL and ≤50 copies per mL was 74% and 62%, respectively. Three subjects (3%) discontinued the study for adverse events, 8 (7%) for virologic failure, and 1 died through a median follow-up of 164 weeks. The annualized incidence rate of grade 3 to 4 adverse events and grade 3 to 4 laboratory abnormalities was 6% and 3%, respectively. The annualized incidence rate of serious adverse events was 9%, with 1% attributed as related to emtricitabine. Genotypic analysis showed the emergence of the M184V mutation in 4 of the 15 subjects who experienced virologic failure through week 164. Pharmacokinetic evaluation demonstrated plasma drug exposures in these children comparable to adults receiving the approved dose of 200 mg once daily.CONCLUSIONS. These results demonstrate the safety and efficacy of emtricitabine in pediatric patients. They also support that the safety and efficacy profile of emtricitabine in children is similar to that demonstrated in adults.

Partial least squares (PLS) is a modeling technique that has met with considerable success, particularly in the fields of chemometrics and psychometrics. In this paper, we extend linear PLS to a nonlinear version called ''reciprocal curves.'' Reciprocal curves are smooth one-dimensional curves that pass through the center of the data, are co-consistent and share several optimality properties originally identified with PLS.

Human immunodeficiency virus (HIV)-infected South African patients (n=468) received blinded lamivudine or emtricitabine, stavudine, and either nevirapine or efavirenz (based on screening viral load). Baseline characteristics were analyzed in univariate and multivariate regression, to identify risk factors for hepatotoxicity (grade 3 or greater increase in serum aminotransferase levels). The occurrence of early hepatotoxicity was 17% in the nevirapine group and 0% in the efavirenz group and was balanced between the lamivudine and emtricitabine arms. Two subjects died of hepatic failure. Independent risk factors were body-mass index (BMI)18.5, female sex, serum albumin level35 g/L, mean corpuscular volume85 fL, plasma HIV-1 RNA load20,000 copies/mL, aspartate aminotransferase level75 IU/L, and lactate dehydrogenase level164 IU/L. The use of nevirapine in female patients with a low BMI should be discouraged.

This study examined factors related to tobacco use among youth from tobacco-raising (TRH) and nonraising households (NRH). The subjects were 3,851 seventh-grade students from 19 middle schools located in a tobacco-raising region. Valid self-reports of tobacco use were encouraged by the use of a test for carbon monoxide in expired air. Cigarette use was higher when 1. (a) at least one parent smoked, and/or 2. (b) the student personally raised tobacco. A boy who personally raised tobacco and had at least one parent who smoked was 10.2 times more likely to have smoked in the last 7 days than a boy from a nonraising household in which neither parent smoked. For girls, the odds ratio was 5.6:1. Tobacco use among students in this high-risk group was higher than rates reported in national or regional studies. Other results were: 1. (1) use began very early — 16% of the students had tried cigarettes and 13% of the boys had tried smokeless tobacco (SLT) in Grade 3 or earlier: and 2. (2) users reported more lenient rules at home regarding tobacco use than did nonusers. Years from now, these high-risk students are likely to be major contributors to increased morbidity and mortality due to tobacco use. Implications for tobacco prevention in tobacco-raising areas are discussed.

Many statistical techniques require that computations be done on all subsets of size r in a data set of size n. Typically, this is done lexographically, i.e., with nested for-loops. If an exchange one point update formula is available, then it is used on the inner loop. In this paper we discuss a method of counting through all subsets of size r in a data set of size n by changing only one element between successive subsets. Such methods have been studied in the applied mathematics literature but are mostly unknown to statisticians. The advantage of such methods is that an update formula can be used at every step, thus potentially saving computation time. The method used to compute the next subset in the list requires some computation time, and thus the new method will only be faster if the update formula is sufficiently faster than doing the computation from scratch.

It is still widely unknown in chemometrics that the statistical analysis of compositional data requires fundamentally different tools than a similar analysis of unconstrained data. This article examines the problems that potentially occur when one performs a partial least squares (PLS) analysis on compositional data and suggests logcontrast partial least squares (LCPLS) as an alternative.

The presence of drug-associated mutations among ART-naive, HIV-1(+) patients may compromise the response to antiviral therapy. We evaluated the effect of preexisting drug-associated resistance mutations to the response in treatment-naive patients to therapy with emtricitabine (FTC) or stavudine (d4T) in combination with didanosine (ddI) and efavirenz (EFV). Study FTC-301A compared emtricitabine once daily (QD) with stavudine twice daily in combination with didanosine and efavirenz in ART-naive patients. Genotypic analysis was performed on baseline plasma HIV-1 RNA for all available samples and at time of virologic failure (VF). Drug resistance mutations present at baseline were evaluated as predictors of VF using logistic regression. VF rates were compared between subgroups using a two-sided exact test. Baseline drug resistance mutations were observed in 90/546 (16.5%) patients: 56/90 (62.2%) with nonnucleoside analogue (NNRTI) mutations and 42/90 (46.6%) with nucleoside analogue mutations. In a stepwise, multiple regression analysis, the presence of the K103N mutation at initiation of therapy was associated with VF in both arms (p = 0.001), however, there was a higher incidence of VF in the stavudine arm compared to the emtricitabine arm regardless of the presence or absence of mutations at baseline (p = 0.001). In this study, the presence of drug-associated resistance mutations in ART-naive patients was significantly correlated with subsequent development of virologic failure underscoring the utility of testing for resistance in addition to the use of potent and well-tolerated first line regimens in treatment-naive patients.

Objective To evaluate the potential for clinically relevant drug interactions between ritonavir-boosted elvitegravir (EVG/r) and the nucleoside reverse transcriptase inhibitors (NRTIs) zidovudine (ZDV), didanosine (ddI), stavudine (d4T), or abacavir (ABC) upon coadministration. Methods In 3 studies, healthy subjects were administered a single dose of ddI, d4T, or ABC, or multiple doses of ZDV, followed by multiple doses of EVG/r alone and together with an NRTI; pharmacokinetics (PK) of EVG and NRTIs were evaluated after individual administration and coadministration. Lack of PK alteration bounds (90% confidence intervals [CI]) for the NRTIs were based on the lack of PK-based dose adjustments per prescribing information. Results Twenty-four of 28, 32/32, and 24/26 subjects completed the ZDV-EVG/r, ddI/d4T-EVG/r, and ABC-EVG/r studies, respectively. All study drugs were well tolerated and no serious adverse events were noted. The PK of ZDV, its glucuronide (G-ZDV), d4T, ABC, and EVG were within the lack of PK alteration 90% CI bounds upon coadministration. Exposures of ddI were modestly (approximately 15%) lower, but these changes are unlikely to be clinically meaningful. Conclusions There are no clinically relevant drug interactions between EVG/r and the NRTIs zidovudine, didanosine, stavudine, or abacavir. These agents can be coadministered without dose adjustment.

Objective Efavirenz (EFV; 600 mg), emtricitabine (FTC; 200 mg) and tenofovir disoproxil fumarate (TDF; 300 mg) are preferred agents for treatment of HIV-1 infection in adults. This study evaluated the pharmacokinetics (PK) and bioequivalence of an investigational coformulation of EFV/FTC/TDF (test) single-tablet regimen compared with the commercially available individual dosage forms (EFV+FTC+TDF; reference treatment) in healthy subjects. Methods Subjects were randomized to 1 of 2 treatment sequences (test-->reference or reference-->test) in an open-label crossover study design. Study drug was administered under fasted conditions, and serial blood samples were obtained over 504 hours after oral administration of each treatment. Formulation bioequivalence was assessed in accordance with the US Food and Drug Administration bioequivalence criteria. Results Forty-eight subjects were enrolled, and 45 completed the study, with all study treatments being generally well tolerated. For EFV (n = 44), the geometric mean ratios (90% confidence interval [CI]) for maximum concentration (C(max)), area under the plasma concentration-time curve from time 0 to the last quantifiable concentration (AUC(0-last)), and area under the plasma concentration-time curve from time 0 extrapolated to infinity (AUC(inf)) were 99.9 (93.4 to 107), 95.7 (90.5 to 101), and 95.2 (88.9 to 102), respectively. For FTC (n = 45), the geometric mean ratios (90% CI) for C(max), AUC(0-last), and AUC(inf) were 88.8 (84.0 to 93.9), 98.0 (94.9 to 101), and 98.0 (94.9 to 101), respectively. For tenofovir (n = 45), the geometric mean ratios (90% CI) for C(max), AUC(0-last), and AUC(inf) were 91.5 (84.6 to 98.8), 99.3 (91.0 to 108), and 100 (93.2 to 108), respectively. Conclusions The coformulation of EFV/FTC/TDF is bioequivalent to administration of its individual components.

Associations have been reported between an MDR1 variant and responses to nonnucleoside reverse-transcriptase inhibitors. We explored associations between MDR1, CYP2B6, and CYP3A polymorphisms and nevirapine hepatotoxicity. Among participants in a randomized study in South Africa (FTC-302), MDR1 3435C-->T was significantly associated with decreased risk of hepatotoxicity (risk ratio, 0.30; P=.016).

Emtricitabine is a new, once-daily nucleoside reverse transcriptase inhibitor (NRTI) with potent activity against human immunodeficiency virus (HIV).To assess the efficacy and safety of emtricitabine as compared with stavudine when used with a background regimen of didanosine and efavirenz.Randomized, double-blind, double-dummy study conducted at 101 research clinics in North America, Latin America, and Europe. The first patient was enrolled on August 21, 2000; no investigator or patient was unblinded until the last patient randomized completed the week 48 visit on October 24, 2002. Analyses were based on data collected in a double-blind setting with a median follow-up of 60 weeks. Patients were 571 antiretroviral-naive, HIV-1-infected adults aged 18 years or older with viral load levels greater than or equal to 5000 copies/mL.Receipt of either 200 mg of emtricitabine once daily (plus stavudine placebo twice daily) (n = 286) or stavudine at standard doses twice daily (plus emtricitabine placebo once daily) (n = 285) plus open-label didanosine and efavirenz, once daily.Persistent virological response, defined as achieving and maintaining viral load at or below the limit of assay quantification (or =400 or 50 copies/mL).At the interim analysis on June 14, 2002, when the last patient randomized completed 24 weeks of double-blind treatment (median follow-up time of 42 weeks), patients in the emtricitabine group had a higher probability of a persistent virological responseor =50 copies/mL vs the stavudine group (85% vs 76%, P =.005). This was associated with a higher mean CD4 cell count change from baseline for the emtricitabine group (156 cells/ microL vs 119 cells/microL, P =.01 [of note, there was no statistical difference at 48 weeks [P =.15], although a sensitivity analysis, using an intent-to-treat population with the last CD4 cell count observation carried forward to week 48 showed a difference [P =.02]]). The independent data and safety monitoring board recommended offering open-label emtricitabine based on the interim analysis. The probability of persistent virological responseor =50 copies/mL through week 60 was 76% for the emtricitabine group vs 54% for the stavudine group (P.001). The probability of virological failure through week 60 was 4% in the emtricitabine group and 12% in the stavudine group (P.001). Patients in the stavudine group had a greater probability of an adverse event that led to study drug discontinuation through week 60 than did those in the emtricitabine group (15% vs 7%, P =.005).Once-daily emtricitabine appeared to demonstrate greater virological efficacy, durability of response, and tolerability compared with twice-daily stavudine when used with once-daily didanosine and efavirenz.

ContextEmtricitabine is a new, once-daily nucleoside reverse transcriptase inhibitor (NRTI) with potent activity against human immunodeficiency virus (HIV).ObjectiveTo assess the efficacy and safety of emtricitabine as compared with stavudine when used with a background regimen of didanosine and efavirenz.Design, Setting, and PatientsRandomized, double-blind, double-dummy study conducted at 101 research clinics in North America, Latin America, and Europe. The first patient was enrolled on August 21, 2000; no investigator or patient was unblinded until the last patient randomized completed the week 48 visit on October 24, 2002. Analyses were based on data collected in a double-blind setting with a median follow-up of 60 weeks. Patients were 571 antiretroviral-naive, HIV-1–infected adults aged 18 years or older with viral load levels greater than or equal to 5000 copies/mL.InterventionsReceipt of either 200 mg of emtricitabine once daily (plus stavudine placebo twice daily) (n = 286) or stavudine at standard doses twice daily (plus emtricitabine placebo once daily) (n = 285) plus open-label didanosine and efavirenz, once daily.Main Outcome MeasurePersistent virological response, defined as achieving and maintaining viral load at or below the limit of assay quantification (≤400 or 50 copies/mL).ResultsAt the interim analysis on June 14, 2002, when the last patient randomized completed 24 weeks of double-blind treatment (median follow-up time of 42 weeks), patients in the emtricitabine group had a higher probability of a persistent virological response ≤50 copies/mL vs the stavudine group (85% vs 76%, P = .005). This was associated with a higher mean CD4 cell count change from baseline for the emtricitabine group (156 cells/µL vs 119 cells/µL, P = .01 [of note, there was no statistical difference at 48 weeks {P = .15}, although a sensitivity analysis, using an intent-to-treat population with the last CD4 cell count observation carried forward to week 48 showed a difference {P = .02}]). The independent data and safety monitoring board recommended offering open-label emtricitabine based on the interim analysis. The probability of persistent virological response ≤50 copies/mL through week 60 was 76% for the emtricitabine group vs 54% for the stavudine group (P