Browsing by Author "Schechter, Mauro"

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    Cancer in HIV-Infected Persons From the Caribbean, Central and South America
    (2011) Fink, Valeria; Shepherd, Bryan E.; Cesar, Carina; Krolewiecki, Alejandro J.; Wehbe, Francisco; Cortes, Claudia; Crabtree-Ramirez, Brenda; Padgett, Denis; Shafaee, Mehdi; Schechter, Mauro; Gotuzzo, Eduardo; Bacon, Melanie; McGowan, Catherine C.; Cahn, Pedro; Masys, Daniel R.; Caribbean Central South America Network for HIV Research Collaboration of the International Epidemiologic Databases to Evaluate AIDS Program
    Background: HIV-infected individuals have heightened cancer risk. With the advent of highly active antiretroviral therapy (HAART), the frequency of some AIDS-defining cancers (ADC) has decreased although certain non-AIDS-defining cancers (NADC) are becoming more frequent. Cancers among HIV-infected individuals in Latin American and the Caribbean have not yet been carefully studied. Methods: Cancer cases among the Caribbean, Central and South American network for HIV Research (CCASAnet) cohort were identified reviewing clinical records and pre-existing databases. Results: There were 406 cancers reported: 331 ADC (224 Kaposi sarcomas and 98 non Hodgkin lymphomas). Most frequent NADC (n = 75) were Hodgkin lymphoma and skin cancers. Seventy-three percent of NADC and 45% of ADC were diagnosed >1 year after HIV diagnosis. Fifty-six percent of ADC occurred before HAART start. Median time from HAART start until cancer diagnosis was 2.5 years for NADC and 0.5 years for ADC (P = <0.001). Within 3372 HAART starters, 158 were diagnosed with 165 cancers (82.4% ADC); 85 cases were previous to or concomitant with HAART initiation. Incidence of cancer after HAART initiation in 8080 person-years of follow-up was 7.2 per 1000 person-years (95% confidence interval = 5.5 to 9.3) for ADC and 2.7 (95% confidence interval = 1.8 to 4.1) for NADC; incidence was higher in the first 2 months, particularly for ADC (47.6). A pre-HAART ADC was a predictor of mortality after adjusting for age, sex, and CD4 at HAART initiation. Conclusions: ADC were the most frequent cancers in this region and were often diagnosed close to HIV diagnosis and HAART start. Incidence of cancer was highest around HAART initiation.
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    Cohort Profile: Caribbean, Central and South America Network for HIV research (CCASAnet) collaboration within the International Epidemiologic Databases to Evaluate AIDS (IeDEA) programme
    (2007-09-10) McGowan, Catherine C; Cahn, Pedro; Gotuzzo, Eduardo; Padgett, Denis; Pape, Jean W; Wolff, Marcelo; Schechter, Mauro; Masys, Daniel R
    How did the study come about? The HIV/AIDS epidemic has evolved in its third decade to be an unprecedented human catastrophe of global scale and importance. Although an historic response for change and intervention has led to decreased rates of new infections and HIV-associated mortality in many communities, the enormity of the pandemic continues to overwhelm already constrained resources everywhere. Improved understanding of antiretroviral therapy (ART) responses and viral and host characteristics, both within and between diverse settings and populations, is needed to guide initiatives in HIV prevention and treatment worldwide.
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    Duration of anti-tuberculosis therapy and timing of antiretroviral therapy initiation: association with mortality in HIV-related tuberculosis
    (2013) Cortes, Claudia; Wehbe, Firas H.; McGowan, Catherine C.; Shepherd, Bryan E.; Duda, Stephany N.; Jenkins, Cathy A.; Gonzalez, Elsa; Carriquiry, Gabriela; Schechter, Mauro; Padgett, Denis; Cesar, Carina; Sierra Madero, Juan; Pape, Jean W.; Masys, Daniel R.; Sterling, Timothy R. ; South American Network for HIV Research (CCASA-net) of the International Epidemiologic Databases to Evaluate AIDS (IeDEA)
    Background Antiretroviral therapy (ART) decreases mortality risk in HIV-infected tuberculosis patients, but the effect of the duration of anti-tuberculosis therapy and timing of anti-tuberculosis therapy initiation in relation to ART initiation on mortality, is unclear. Methods We conducted a retrospective observational multi-center cohort study among HIV-infected persons concomitantly treated with Rifamycin-based anti-tuberculosis therapy and ART in Latin America. The study population included persons for whom 6 months of anti-tuberculosis therapy is recommended. Results Of 253 patients who met inclusion criteria, median CD4+ lymphocyte count at ART initiation was 64 cells/mm3, 171 (68%) received >180 days of anti-tuberculosis therapy, 168 (66%) initiated anti-tuberculosis therapy before ART, and 43 (17%) died. In a multivariate Cox proportional hazards model that adjusted for CD4+ lymphocytes and HIV-1 RNA, tuberculosis diagnosed after ART initiation was associated with an increased risk of death compared to tuberculosis diagnosis before ART initiation (HR 2.40; 95% CI 1.15, 5.02; P = 0.02). In a separate model among patients surviving >6 months after tuberculosis diagnosis, after adjusting for CD4+ lymphocytes, HIV-1 RNA, and timing of ART initiation relative to tuberculosis diagnosis, receipt of >6 months of anti-tuberculosis therapy was associated with a decreased risk of death (HR 0.23; 95% CI 0.08, 0.66; P=0.007). Conclusions The increased risk of death among persons diagnosed with tuberculosis after ART initiation highlights the importance of screening for tuberculosis before ART initiation. The decreased risk of death among persons receiving > 6 months of anti-tuberculosis therapy suggests that current anti-tuberculosis treatment duration guidelines should be re-evaluated.
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    Effectiveness of Protease Inhibitor Monotherapy versus Combination Antiretroviral Maintenance Therapy: A Meta-Analysis
    (2011) Mathis, Steven; Khanlari, Babak; Pulido, Francisco; Schechter, Mauro; Negredo, Eugenia; Nelson, Mark; Vernazza, Pietro; Cahn, Pedro; Meynard, Jean-Luc; Arribas, Jose; Bucher, Heiner C.
    Background: The unparalleled success of combination antiretroviral therapy (cART) is based on the combination of three drugs from two classes. There is insufficient evidence whether simplification to ritonavir boosted protease inhibitor (PI/r) monotherapy in virologically suppressed HIV-infected patients is effective and safe to reduce cART side effects and costs. Methods: We systematically searched Medline, Embase, the Cochrane Library, conference proceedings and trial registries to identify all randomised controlled trials comparing PI/r monotherapy to cART in suppressed patients. We calculated in an intention to treat (loss-of follow-up, discontinuation of assigned drugs equals failure) and per-protocol analysis (exclusion of protocol violators following randomisation) and based on three different definitions for virological failure pooled risk ratios for remaining virologically suppressed. Findings: We identified 10 trials comparing 3 different PIs with cART based on a PI/r plus 2 reverse transcriptase inhibitors in 1189 patients. With the most conservative approach (viral load <50 copies/ml on two consecutive measurements), the risk ratios for viral suppression at 48 weeks of PI/r monotherapy compared to cART were in the ITT analysis 0.94 8 (95% CI 0.89 to 1.00) p = 0.06; risk difference -0.06 (95%CI -0.11 to 0) p = 0.05, p for heterogeneity = 0.08, I(2) = 43.1%) and in the PP analysis 0.93 ((95%CI 0.90 to 0.97) p<0.001; risk difference -0.07 (95%CI -0.10 to -0.03) p<0.001, p for heterogeneity = 0.44, I(2) = 0%). Reintroduction of cART in 44 patients with virological failure led in 93% to de-novo viral suppression. Interpretation: Virologically well suppressed HIV-infected patients have a lower chance to maintain viral suppression when switching from cART to PI/r monotherapy. Failing patients achieve high rates of de-novo viral suppression following reintroduction of reverse transcriptase inhibitors.
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    Efficacy and safety of etravirine in treatment-experienced, HIV-1 patients: pooled 48 week analysis of two randomized, controlled trials
    (2009) Katlama, Christine; Haubrich, Richard; Lalezari, Jacob; Lazzarin, Adriano; Madruga, Jose V.; Molina, Jean-Michel; Schechter, Mauro; Peeters, Monika; Picchio, Gaston; Vingerhoets, Johan; Woodfall, Brian; De Smedt, Goedele; DUET-1; DUET-2 study groups
    Objective: To evaluate the efficacy, safety and virologic resistance profile of etravirine (TMC125), a next-generation nonnucleoside reverse transcriptase inhibitor, over 48 weeks in treatment-experienced adults infected with HIV-1 strains resistant to a nonnucleoside reverse transcriptase inhibitor and other antiretrovirals. Design: DUET-1 (NCT00254046) and DUET-2 (NCT00255099) are two identically designed, randomized, double-blind phase III trials. Methods: Patients received twice-daily etravirine 200 mg or placebo, each plus a background regimen of darunavir/ritonavir, investigator-selected nucleoside/nucleotide reverse transcriptase inhibitors and optional enfuvirtide. Eligible patients had documented nonnucleoside reverse transcriptase inhibitor resistance, at least three primary protease inhibitor mutations at screening and were on a stable but virologically failing regimen for at least 8 weeks, with plasma viral load more than 5000 copies/ml. Pooled 48-week data from the two trials are presented. Results: Patients (1203) were randomized and treated (n = 599, etravirine; n = 604, placebo). Significantly more patients in the etravirine than in the placebo group achieved viral load less than 50 copies/ml at week 48 (61 vs. 40%, respectively; P < 0.0001). Significantly fewer patients in the etravirine group experienced at least one confirmed or probable AIDS-defining illness/death (6 vs. 10%; P = 0.0408). Safety and tolerability in the etravirine group was comparable to the placebo group. Rash was the only adverse event to occur at a significantly higher incidence in the etravirine group (19 vs. 11%, respectively, P < 0.0001), occurring primarily in the second week of treatment. Conclusion: At 48 weeks, treatment-experienced patients receiving etravirine plus background regimen had statistically superior and durable virologic responses (viral load less than 50 copies/ml) than those receiving placebo plus background regimen, with comparable tolerability and no new safety signals reported since week 24.
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    Mortality During the First Year of Potent Antiretroviral Therapy in HIV-1-Infected Patients in 7 Sites Throughout Latin America and the Caribbean
    (2009) Tuboi, Suely H.; Schechter, Mauro; McGowan, Catherine C.; Cesar, Carina; Krolewiecki, Alejandro J.; Cahn, Pedro; Wolff, Marcelo; Pape, Jean W.; Padgett, Denis; Sierra Madero, Juan; Gotuzzo, Eduardo; Masys, Daniel R.; Shepherd, Bryan E.
    Background: Although nearly 2 million people live with HIV in Latin America and the Caribbean, mortality rates after initiation of highly active antiretroviral therapy (HAART) have not been well described. Methods: Five thousand one hundred fifty-two HIV-infected, antiretroviral-naive adults from clinics in Argentina, Brazil, Chile, Haiti, Honduras, Mexico, and Peru starting HAART during 1996-2007 were included. First-year mortality rates and their association with demographics, regimen, baseline CD4, and clinical stage were assessed. Results: Overall 1-year mortality rate was 8.3% [95% confidence interval (CI): 7.6% to 9.1%], although variable across sites: 2.6%, 3.7%, 6.0%, 13.0%, 10.8%, 3.5%, and 9.8% for clinics in Argentina, Brazil, Chile, Haiti, Honduras, Mexico, and Peru, respectively. Eighty percent of deaths occurred within the first 6 months. Median baseline CD4 was 107 cells per milliliter, ranging from 79 (Peru) to 163 (Argentina). Mortality estimates adjusting for CD4 were similar across sites (1.1%-2.8% for CD4 = 200), except for Haiti, 7.5%, and Honduras, 7.0%. Death was associated with lower CD4 [adjusted hazard ratio for CD4 = 200 vs. CD4 = 50 was 0.58; 95% CI: 0.40 to 0.85] and clinical AIDS (hazard ratio = 3.1; 95% CI: 2.1 to 4.5). Conclusions: Mortality rates were similar to those reported elsewhere for resource-limited settings. Disease stage at HAART initiation, treatment eligibility criteria, program age, and background mortality rates may explain some variability in prognosis between sites.
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    Nevirapine and Efavirenz Elicit Different Changes in Lipid Profiles in Antiretroviral- Therapy-Naive Patients Infected with HIV-1
    (2004-10-19) Van Leth, Frank; Phanuphak, Prahpan; Stroes, Erik; Gazzard, Brian; Cahn, Pedro; Raffi, François; Wood, Robin; Bloch, Mark; Katlama, Christine; Kastelein, John JP; Schechter, Mauro; Murphy, Robert L; Horban, Andrzej; Hall, David B; Lange, Joep MA
    Background Patients infected with HIV-1 initiating antiretroviral therapy (ART) containing a non-nucleoside reverse transcriptase inhibitor (NNRTI) show presumably fewer atherogenic lipid changes than those initiating most ARTs containing a protease inhibitor. We analysed whether lipid changes differed between the two most commonly used NNRTIs, nevirapine (NVP) and efavirenz (EFV). Methods and Findings Prospective analysis of lipids and lipoproteins was performed in patients enrolled in the NVP and EFV treatment groups of the 2NN study who remained on allocated treatment during 48 wk of follow-up. Patients were allocated to NVP (n = 417), or EFV (n = 289) in combination with stavudine and lamivudine. The primary endpoint was percentage change over 48 wk in high-density lipoprotein cholesterol (HDL-c), total cholesterol (TC), TC:HDL-c ratio, non-HDL-c, low-density lipoprotein cholesterol, and triglycerides. The increase of HDL-c was significantly larger for patients receiving NVP (42.5%) than for patients receiving EFV (33.7%; p = 0.036), while the increase in TC was lower (26.9% and 31.1%, respectively; p = 0.073), resulting in a decrease of the TC:HDL-c ratio for patients receiving NVP (−4.1%) and an increase for patients receiving EFV (+5.9%; p < 0.001). The increase of non-HDL-c was smaller for patients receiving NVP (24.7%) than for patients receiving EFV (33.6%; p = 0.007), as were the increases of triglycerides (20.1% and 49.0%, respectively; p < 0.001) and low-density lipoprotein cholesterol (35.0% and 40.0%, respectively; p = 0.378). These differences remained, or even increased, after adjusting for changes in HIV-1 RNA and CD4+ cell levels, indicating an effect of the drugs on lipids over and above that which may be explained by suppression of HIV-1 infection. The increases in HDL-c were of the same order of magnitude as those seen with the use of the investigational HDL-c-increasing drugs. Conclusion NVP-containing ART shows larger increases in HDL-c and decreases in TC:HDL-c ratio than an EFV-containing regimen. Based on these findings, protease-inhibitor-sparing regimens based on non-nucleoside reverse transcriptase inhibitor, particularly those containing NVP, may be expected to result in a reduced risk of coronary heart disease.
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    Predictors of adherence and virologic outcome in HIV-infected patients treated with abacavir- or indinavir-based triple combination HAART also containing lamivudine/zidovudine
    (2004) Cahn, Pedro; Vibhagool, Asda; Schechter, Mauro; Soto-Ramirez, Leopoldo; Carosi, Giampiero; Smaill, Fraser; Jordan, James C.; Pharo, Carol E.; Thomas, Nancy E.; Steel, Harry M.
    Objectives: To compare dosing convenience and adherence with abacavir (ABC) 300 mg plus a fixed-dose lamivudine 150 mg/zidovudine 300 mg combination tablet (COM) twice daily versus indinavir (IDV) plus COM twice daily in treatment-naïve, HIV-1-infected adults; and to evaluate the association among difficulty taking antiretroviral regimens, adherence, and virologic efficacy. Methods: An open-label, randomized, multicenter, international study compared the COM/ABC and IDV/COM regimens with respect to self-reported adherence and regimen convenience over 48 weeks. Logistic regression analysis (LRA) was done on a patient sub-sample from both groups to evaluate predictors of adherence and virologic response at last time-point on randomized therapy (LTORT). Results: The study population was diverse with respect to ethnicity (38% Asian, 27% Hispanic, 28% white, 3% black, 4% other) and gender (39% women, 61% men). Baseline median HIV-1 RNA was 4.80 log(10) copies/mL and CD4+ cell count was 315 cells/mm(3). Of 329 patients who were randomized and received treatment, 315 (96%) provided adherence data. Significantly more patients in the ABC/COM group than in the IDV/COM group reported > or = 95% adherence to therapy (76 vs 58%, p < 0.001) and no difficulty in taking their regimen (91 vs 61%, p < 0.001). In both groups, the highest probability of HIV-1 RNA < 400 copies/mL occurred when median adherence was > or = 95%. The probability of HIV-1 RNA < 400 copies/mL declined more rapidly in the IDV/COM group as adherence rates decreased. LRA showed that no difficulty taking any of the drugs in the regimen, ABC/COM treatment group, and male gender were independent significant predictors of > or = 95% adherence (p < 0.05). Median adherence and baseline HIV-1 RNA were significant predictors of HIV-1 RNA < 400 copies/mL (p < 0.05). Conclusions: Patients reported greater ease of use and superior adherence to ABC/COM than IDV/COM. Patient-reported difficulty taking drugs in a regimen was predictive of reduced adherence, and both of the latter factors were predictive of poorer virologic outcome. Adherence levels of > or = 95% in both treatment groups maximized the probability of patients achieving an HIV-1 RNA < 400 copies/mL.
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    Prioritising prevention strategies for patients in Antiretroviral Treatment Programmes in Resource-Limited Settings
    (2010) Spaar, Alexandra; Graber, Christian; Dabis, Francois; Coutsoudis, Anna; Bachmann, Lorenz; McIntyre, James; Schechter, Mauro; Prozesky, Hans W.; Tuboi, Suely H.; Dickinson, David; Kumarasamy, N.; Pujades-Rodriguez, Maria; Sprinz, Eduardo; Schilthuis, Hans J.; Cahn, Pedro; Low, Nicola; Egger, Matthias; ART-LINC of IeDEA
    Expanded access to antiretroviral therapy (ART) offers opportunities to strengthen HIV prevention in resource-limited settings. We invited 27 ART programmes from urban settings in Africa, Asia and South America to participate in a survey, with the aim to examine what preventive services had been integrated in ART programmes. Twenty-two programmes participated; eight (36%) from South Africa, two from Brazil, two from Zambia and one each from Argentina, India, Thailand, Botswana, Ivory Coast, Malawi, Morocco, Uganda and Zimbabwe and one occupational programme of a brewery company included five countries (Nigeria, Republic of Congo, Democratic Republic of Congo, Rwanda and Burundi). Twenty-one sites (96%) provided health education and social support, and 18 (82%) provided HIV testing and counselling. All sites encouraged disclosure of HIV infection to spouses and partners, but only 11 (50%) had a protocol for partner notification. Twenty-one sites (96%) supplied male condoms, seven (32%) female condoms and 20 (91%) provided prophylactic ART for the prevention of mother-to child transmission. Seven sites (33%) regularly screened for sexually transmitted infections (STI). Twelve sites (55%) were involved in activities aimed at women or adolescents, and 10 sites (46%) in activities aimed at serodiscordant couples. Stigma and discrimination, gender roles and funding constraints were perceived as the main obstacles to effective prevention in ART programmes. We conclude that preventive services in ART programmes in lower income countries focus on health education and the provision of social support and male condoms. Strategies that might be equally or more important in this setting, including partner notification, prompt diagnosis and treatment of STI and reduction of stigma in the community, have not been implemented widely.
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    Rates and Reasons for Early Change of First HAART in HIV-1-Infected Patients in 7 Sites throughout the Caribbean and Latin America
    (2010) Cesar, Carina; Shepherd, Bryan E.; Krolewiecki, Alejandro J.; Fink, Valeria; Schechter, Mauro; Tuboi, Suely H.; Wolff, Marcelo; Pape, Jean W.; Leger, Paul; Padgett, Denis; Sierra Madero, Juan; Gotuzzo, Eduardo; Sued, Omar; McGowan, Catherine C.; Masys, Daniel R.; Cahn, Pedro; Caribbean, Central and South America Network for HIV Research (CCASAnet) Collaboration; International Epidemiologic Databases to Evaluate AIDS (IeDEA) Program
    Background: HAART rollout in Latin America and the Caribbean has increased from approximately 210,000 in 2003 to 390,000 patients in 2007, covering 62% (51%-70%) of eligible patients, with considerable variation among countries. No multi-cohort study has examined rates of and reasons for change of initial HAART in this region. Methodology: Antiretroviral-naïve patients >or= 18 years who started HAART between 1996 and 2007 and had at least one follow-up visit from sites in Argentina, Brazil, Chile, Haiti, Honduras, Mexico and Peru were included. Time from HAART initiation to change (stopping or switching any antiretrovirals) was estimated using Kaplan-Meier techniques. Cox proportional hazards modeled the associations between change and demographics, initial regimen, baseline CD4 count, and clinical stage. Principal findings: Of 5026 HIV-infected patients, 35% were female, median age at HAART initiation was 37 years (interquartile range [IQR], 31-44), and median CD4 count was 105 cells/uL (IQR, 38-200). Estimated probabilities of changing within 3 months and one year of HAART initiation were 16% (95% confidence interval (CI) 15-17%) and 28% (95% CI 27-29%), respectively. Efavirenz-based regimens and no clinical AIDS at HAART initiation were associated with lower risk of change (hazard ratio (HR) = 1.7 (95% CI 1.1-2.6) and 2.1 (95% CI 1.7-2.5) comparing neverapine-based regimens and other regimens to efavirenz, respectively; HR = 1.3 (95% CI 1.1-1.5) for clinical AIDS at HAART initiation). The primary reason for change among HAART initiators were adverse events (14%), death (5.7%) and failure (1.3%) with specific toxicities varying among sites. After change, most patients remained in first line regimens. Conclusions: Adverse events were the leading cause for changing initial HAART. Predictors for change due to any reason were AIDS at baseline and the use of a non-efavirenz containing regimen. Differences between participant sites were observed and require further investigation.
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    Triple nucleoside treatment with abacavir plus the lamivudine/zidovudine combination tablet (COM) compared to indinavir/COM in antiretroviral therapy-naïve adults: Results of a 48-week open-label, equivalence trial (CNA3014)
    (2004) Vibhagool, Asda; Cahn, Pedro; Schechter, Mauro; Smaill, Fraser; Soto-Ramirez, Leopoldo; Carosi, Giampiero; Montroni, Marco; Pharo, Carol E.; Jordan, James C.; Thomas, Nancy E.; Pearce, Grant
    Objective: An equivalence (non-inferiority) trial comparing antiviral response, tolerability, and adherence with a triple nucleoside regimen containing abacavir 300 mg (ABC) plus a lamivudine 150-mg/zidovudine 300-mg combination tablet (COM) twice daily vs. a regimen containing the protease inhibitor indinavir (IDV) 800 mg three times daily plus COM twice daily (IDV/COM) in antiretroviral-naïve, HIV-infected patients. Methods: Adult patients with plasma HIV-1 RNA levels ≥ 5000 copies/mL and CD4+ cell counts ≥ 100 cells/mm3 were randomized to receive open-label ABC/COM (n = 169) or IDV/COM (n = 173) for 48 weeks. The intent-to-treat (ITT) population was the primary population evaluated. ITT: switch/missing equals failure (ITT: S/M = F) and as-treated (AT) analyses were used for assessing the proportion of patients achieving plasma HIV-1 RNA level < 400 and < 50 copies/mL at each clinic visit. In the ITT: S/M = F analysis, patients who switched treatment or had missing values were considered treatment failures; the AT analysis examined virologic data only while patients received study treatment. ABC/COM was considered equivalent (non-inferior) to IDV/COM if the lower limit of the 95% confidence intervals (CIs) about the difference in proportions of ABC/COM- vs. IDV/COM-treated patients attaining plasma HIV-1 RNA < 400 copies/mL exceeded –15% at week 48. Results: The study population was diverse with respect to ethnicity (38% Asian, 27% Hispanic, 28% white, 3% black, 4% other) and gender (39% women, 61% men). Baseline median HIV-1 RNA was 4.80 log10 copies/mL and CD4+ cell count was 315 cells/mm3. ABC/COM met the criterion of equivalence to IDV/COM. In the ITT: S/M = F analysis at Week 48, a greater proportion of ABC/COM-treated patients achieved HIV-1 RNA < 400 copies/mL (66% [109/164] vs. 50% [82/165]; treatment difference 16.6%, 95% CI (6.0, 27.2), p = 0.002) and HIV-1 RNA < 50 copies/mL (60% [99/164] vs. 50% [83/165]; treatment difference 9.6%, 95% CI [–1.1, 20.2]), whereas the AT analysis showed similar proportions achieving these endpoints (< 400 copies/mL: 85 vs. 83%; < 50 copies/mL: 79 vs 81%). Comparable proportions of patients with screening HIV-1 RNA values > 100 000 copies/mL achieved HIV-1 RNA < 400 copies/mL (ABC/COM: 60% [35/58]; IDV/COM: 51% [33/65]; treatment difference 9.6%, 95% CI [–7.9, 27.1]; ITT: S/M = F analysis). A significantly greater proportion taking ABC/COM were ≥ 95% adherent (72% [109/151] vs. 45% [70/154] with IDV/COM, p < 0.001). Median increases from baseline in CD4+ cell counts were similar in the two treatment groups (+148 vs. +152 cells/mm3). Significantly more patients on IDV/COM reported drug-related adverse events (87% [142/165] vs. 65% [108/164] with ABC/COM, p < 0.001), similar proportions discontinued treatment due to adverse events (13 vs. 10%), and a slightly greater proportion in the ABC/COM group reported serious adverse events (13 vs. 8%). About half of the latter comprised suspected ABC-related hypersensitivity reactions (overall rate, 6%). Most adverse events were gastrointestinal in nature in both treatment groups. Conclusion: ABC/COM was at least equivalent to IDV/COM over 48 weeks in the treatment of antiretroviral-naïve patients. ABC/COM was associated with a significantly higher adherence rate and lower incidence of drug-related adverse events than IDV/COM. The study was limited in that it was not powered to determine equivalence of treatments within high vs. low viral load strata, adherence was not monitored electronically, and bias could not be ruled out due to the open-label study design.