Early Virologic Response to Abacavir/Lamivudine and Tenofovir/Emtricitabine During ACTG A5202

Abstract

Background: ACTG A5202 randomized treatment-naïve individuals to tenofovir-emtricitabine (TDF/FTC) or abacavir-lamivudine (ABC/3TC) combined with efavirenz (EFV) or atazanavir/ritonavir (ATV/r). Individuals in the high screening viral load (VL) stratum (≥100,000 copies/mL) had increased rates of virologic failure with ABC/3TC. Objective: To compare regimen-specific early virologic response. Methods: Using Wilcoxon rank-sum tests, we compared regimen-specific VL changes from entry to week 4 in A5202 subjects (N = 1,813) and from entry to week 1, 2, and 4 in substudy subjects (n = 179). We evaluated associations between week 4 VL change and time to virologic failure with Cox proportional hazards models. Results: TDF/FTC and ABC/3TC produced similar week 4 VL declines in the entire study population and in the high VL stratum. EFV produced greater VL declines from baseline at week 4 than ATV/r (median -2.1 vs -1.9 log₁₀ copies/mL; P < .001). In the substudy of subjects with week 1, 2, and 4 VL data, there was no difference in VL decline in individuals randomized to TDF/FTC versus ABC/3TC, but EFV resulted in greater VL decline from entry at each of these timepoints than ATV/r. Smaller week 4 VL decline was associated with increased risk of virologic failure. Conclusions: Within all treatment arms, a less robust week 4 virologic response was associated with higher risk for subsequent virologic failure. However, between-regimen differences in week 4 VL declines did not parallel the previously reported differences in longer term virologic efficacy in A5202, suggesting that between-regimen differences in responses were not due to intrinsic differences in antiviral activity.     

The Safety and Efficacy of Switching Stavudine to Tenofovir DF in Combination with Lamivudine and Efavirenz in HIV-1—Infected Patients: Three-Year Follow–up After Switching Therapy

Abstract

Background: Study 903 is a phase 3 trial with a completed 144-week, double-blind phase comparing tenofovir DF (TDF) with stavudine (d4T), in combination with lamivudine (3TC) and efavirenz (EFV), and an ongoing 336-week open-label extension phase. Method: Patients in 3 countries completing the d4T treatment phase were allowed to switch d4T to TDF and receive once-daily TDF+3TC+EFV in the extension phase. Results: At the time of switch, 100% and 99% of patients (n = 85; 60% male, 64% White; mean age 37 years; mean CD4 = 650 cells/mm3) had HIV RNA <400 and <50 copies/mL. At 144 weeks after the switch, 89% (missing = failure) had HIV RNA <400 copies/mL and 87% had HIV RNA <50 copies/mL. Mean CD4 cell count increased 155 cells/mm3. No patient had virologic failure. Significant decreases from switch to week 144 in mean fasting total cholesterol (?22 mg/dL, p < .0001) and triglycerides (?78 mg/dL, p < .0001) were observed. Mean limb fat increased significantly from 4.5 kg to 5.8 kg, 144 weeks after switch (p < .0001). Conclusion: In virologically suppressed patients, switching d4T to TDF as part of a once-daily regimen with 3TC and EFV resulted in maintenance of virologic suppression and continued CD4 cell increases through 144 weeks, with significant improvements in metabolic parameters.     

Once-Daily Abacavir/Lamivudine and Ritonavir-Boosted Atazanavir for the Treatment of HIV-1 Infection in Antiretroviral-Naïve Patients: A 48-Week Pilot Study

Abstract

Purpose: To assess the efficacy and safety of a once-daily (QD) regimen consisting of the co-formulation of abacavir/lamivudine (ABC/3TC) and atazanavir plus ritonavir (ATV-RTV) in antiretroviral (ART)-naïve patients with plasma HIV-1 RNA >5,000 copies/mL. Method: This open-label, multicenter study conducted between September 2004 and June 2006 included 112 patients who received ABC 600 mg/3TC 300 mg and ATV 300 mg-RTV 100 mg QD. Drug switches were permitted for ABC hypersensitivity and ATV-related hyperbilirubinemia. Primary endpoints were proportion of patients achieving HIV-1 RNA <50 copies/mL at Week 48 and treatment discontinuation due to study drugs. Results: A total of 111 patients were treated. At Week 48, the proportion of patients achieving HIV-1 RNA <50 copies/mL was 77% (85/111) by intent-to-treat (ITT) missing=failure, switch included response rate. Drug substitutions occurred in 8 (7%) patients for suspected ABC hypersensitivity reaction (HSR) and in 6 (5%) patients for ATV-related toxicities; only 1 patient discontinued study due to ABC HSR. Four patients met confirmed virologic nonresponse (HIV RNA ?400 copies/mL). Treatment-emergent drug resistance was rare, and no patient had virus that developed reduced susceptibility to ATV. Median change from baseline (95% confidence interval) in fasting lipids at Week 48 was 39 (26–66) mg/dL for triglycerides, 28 (22–38) mg/dL for total cholesterol (C), 14 (10.5–16) mg/dL for HDL-C, and 8 (2–16.5) mg/dL for LDL-C. Conclusion: ABC/3TC and ATV-RTV QD is an effective and well-tolerated regimen in ART-naïve patients through 48 weeks, with a modest impact on fasting lipids.     

Efficacy and safety of atazanavir, with or without ritonavir, as part of once-daily highly active antiretroviral therapy regimens in antiretroviral-naive patients

BACKGROUND: Atazanavir (ATV), the first once-daily protease inhibitor approved for the treatment of HIV-1 infection, is recommended for use in antiretroviral (ARV) treatment-naive and -experienced patients. Study AI424-089 was a prospective, randomized, open-label, 96-week study comparing 2 ATV-based treatment regimens in ARV-naive HIV-infected patients. METHODS: Adults with HIV RNA levels > or =2000 copies/mL were randomized (1:1) to once-daily ATV at a dose of 300 mg with ritonavir at a dose of 100 mg (ATV300/RTV) or ATV at a dose of 400 mg (ATV400); both regimens included lamivudine and an investigational extended-release formulation of stavudine. The primary endpoint for this noninferiority study was the proportion of patients (response rate) with an HIV RNA load <400 copies/mL at week 48. RESULTS: Response rates at week 48 were 86% and 85% on the ATV300/RTV and ATV400 regimens, respectively (difference estimate [95% confidence interval] = 1.5 [-8.2 to 11.1]). There were 3 and 10 patients with virologic failure in the ATV300/RTV and ATV400 groups, respectively. One patient (ATV400) developed phenotypic resistance to ATV associated with an I50L substitution. Adverse event-related discontinuations were 8% among ATV300/RTV-treated patients and <1% among ATV400-treated patients. Plasma lipid elevations were low with both regimens. Both regimens were well tolerated. CONCLUSIONS: These findings demonstrate the safety and efficacy of the ATV300/RTV regimen and confirm the safety and efficacy of ATV400 in an ARV-naive patient population.     

Efficacy and safety of “unboosting” atazanavir in a randomized controlled trial among HIV-infected patients receiving tenofovir DF

Objectives: To assess safety and efficacy of a switch to unboosted atazanavir (ATV) among HIV-infected adults receiving ATV/ritonavir (r) and tenofovir disoproxil fumarate (TDF).

Methods: HIV-infected adults with viral load (VL) <40 copies/mL at screening and <150 copies/mL consistently for ≥3 months while receiving a regimen including ATV/r and TDF were randomized to continue ATV/r 300/100 mg daily (control) or change to ATV 400 mg daily (switch), while maintaining their TDF backbone. The primary outcome was proportion of subjects without treatment failure (regimen switch or VL > 200 copies/mL twice consecutively) at 48 weeks.

Results: Fifty participants (46 male, median age 47 years) were randomized, 25 to each arm. At week 48, treatment success occurred in 76% in the control arm and 92% in the switch arm (ITT, p = 0.25). ATV trough levels at week 9 were higher in controls (median 438 ng/mL) than in the switch arm (median 124 ng/mL) (p = 0.003), as was total bilirubin at week 48 (median 38 μmol/L and 28 μmol/L, respectively; p = 0.02). Estimated glomerular filtration rate (eGFR) decreased in the control arm (p = 0.007), but did not change in the switch arm. At week 48, eGFR was higher in the switch arm (median 96 mL/min) than in the control arm (median 85 mL/min) (p = 0.035), but the arms were similar with respect to fasting glucose, C-reactive protein, and lipid parameters.

Conclusions: Switching from ATV/r to unboosted ATV appears to be safe and effective in selected virologically suppressed patients receiving TDF-containing regimens, and may have favorable effects on bilirubin and renal function.     

HIV-infected patients receiving lopinavir/ritonavir-based antiretroviral therapy achieve high rates of virologic suppression despite adherence rates less than 95%

BACKGROUND: The observation that extremely high levels of medication adherence are required to achieve complete virologic suppression is based largely on studies of treatment-experienced patients receiving HIV protease inhibitor (PI)-based therapy without ritonavir boosting. This study aims to define the level of adherence needed to achieve virologic suppression in patients receiving boosted PI-based highly active antiretroviral therapy (HAART) with lopinavir/ritonavir. METHODS: HIV-infected adults receiving a regimen containing lopinavir/ritonavir were recruited into a prospective, observational study of the relation between adherence to lopinavir/ritonavir and virologic outcomes. Adherence was measured using the Medication Event Monitoring System (MEMS; Aardex, Union City, CA). HIV-1 viral load (VL) was measured at week 24. RESULTS: The final study population contained 64 subjects. Eighty percent had AIDS, 97% received lopinavir/ritonavir before enrollment, and most had more than 7 years of HAART experience. Mean adherence overall was 73%. Eighty percent and 59% achieved a VL <400 copies/mL and a VL <75 copies/mL, respectively. Mean adherence was 75% in those achieving a VL <75 copies/mL. High rates of virologic suppression were observed in all adherence quartiles, including the lowest quartile (range of adherence: 23.5%-53.3%). CONCLUSIONS: Moderate levels of adherence can lead to virologic suppression in most patients taking lopinavir/ritonavir-based HAART.     

A once-daily lopinavir/ritonavir-based regimen provides noninferior antiviral activity compared with a twice-daily regimen

OBJECTIVE: To evaluate the safety and noninferiority and to explore the efficacy of administration of once-daily versus twice-daily lopinavir/ritonavir (LPV/r) in antiretroviral-naive HIV-1-infected subjects. DESIGN: Randomized, open-label, multicenter, comparative study. METHODS: One hundred ninety antiretroviral-naive subjects with plasma HIV-1 RNA level >1000 copies/mL and any CD4 cell count were randomized to lopinavir/ritonavir at a dose of 800/200 mg administered once daily (n = 115) or lopinavir/ritonavir at a dose of 400/100 mg administered twice daily (n = 75). Subjects also received tenofovir disoproxil fumarate (TDF) at a dose of 300 mg and emtricitabine (FTC) at a dose of 200 mg administered once daily. RESULTS: The median baseline plasma HIV-1 RNA level and CD4 count were 4.8 log10 copies/mL and 216 cells/mm, respectively. Before week 48, 20% (once daily) and 29% (twice daily) subjects discontinued. Virologic responses of the subjects through 48 weeks were comparable; 70% (once daily) and 64% (twice daily) achieved an HIV-1 RNA level <50 copies/mL by intent-to-treat, noncompleter = failure analysis. No subject demonstrated LPV or TDF resistance, but 3 subjects (2 in the once-daily group, 1 in the twice-daily group) demonstrated FTC resistance. Mean increases in CD4 count were similar. Diarrhea (16% in the once-daily group, 5% in the twice-daily group; P = 0.036) was the most common moderate or severe study drug-related adverse event. CONCLUSIONS: Through 48 weeks, a once-daily regimen of lopinavir/ritonavir + TDF + FTC appears to have similar virologic and immunologic responses in antiretroviral-naive subjects as the same regimen with lopinavir/ritonavir administered twice daily. Both regimens were relatively well tolerated, and no LPV or TDF resistance was observed.     

Three-year durability of dual-nucleoside versus triple-nucleoside therapy in a Thai population with HIV infection

We compared the long-term immunologic and virologic efficacy of the dual- and triple-nucleoside therapy for HIV infection. This was a retrospective analysis of 2 randomized clinical trials in antiretroviral-naive patients. In the dual-nucleoside group, 15 started with didanosine (ddI) monotherapy and then added stavudine (d4T) after 24 weeks, 63 started with various doses of d4T and ddI, and 53 started with zidovudine (ZDV) and lamivudine (3TC). In the triple-nucleoside group, 53 started with ZDV, 3TC, and ddI. After 48 weeks, patients who were not failing were randomized to immediate (before treatment failure) versus delayed (at the time of virologic failure) switching from ddI and d4T to ZDV and 3TC or vice versa and from ZDV, 3TC, and ddI to d4T, 3TC, and abacavir (ABC). Failure was defined as a plasma HIV-1 RNA level>or=1 log10 above nadir or >or=10,000 copies/mL when nadir was <500 copies/mL. Patients failing therapy before week 48 received the new treatment as in the immediate switching group. Hydroxyurea was added to the last treatment regimen if patients failed after week 96. CD4 count and plasma HIV-1 RNA level (branched DNA assay with a cutoff point of 50 copies/mL) at week 144 were analyzed by intention to treat. Compared with the dual-nucleoside group, the triple-nucleoside group had a higher proportion of patients with <50 copies/mL at 144 weeks (60% vs. 18%; P<0.001), higher median CD4 count (388 cells/microL vs. 346 cells/microL; P=0.018), and longer duration of response, defined as the time from onset of viral suppression (<500 copies/mL) to the time of treatment failure (the first of 2 consecutive HIV-1 RNA measurements >500 copies/mL never followed by 2 consecutive visits showing suppressible viremia to <500 copies/mL) or discontinuation from the study (144 weeks vs. 104 weeks; P=0.002). Multivariate regression analyses showed that significant predictors for treatment success, defined as a plasma viral load <50 copies/mL at week 144, were asymptomatic clinical status at enrollment, a baseline plasma viral load 相似文献   

Impact of Switching Virologically Suppressed,HIV-1-Infected Patients from Twice-Daily Fixed-Dose Zidovudine/Lamivudine to Once-Daily Fixed-Dose Tenofovir Disoproxil Fumarate/Emtricitabine

Abstract

Objective: Evaluate the impact of switching from twice-daily zidovudine/lamivudine (AZT/3TC) to once-daily tenofovir DF plus emtricitabine (TDF/FTC) with efavirenz (EFV). Design: Prospective, multicenter, single-arm 24-week trial. Methods: Patients on EFV + AZT/3TC for =8 weeks with HIV-1 RNA <400 copies/mL were switched to EFV + TDF/FTC and assessed for safety/tolerability, virologic and immunologic responses, adherence, and quality of life at 4, 12, and 24 weeks. Results: Of 402 patients, 2% discontinued for an adverse event (AE) and 1 patient for virologic failure. At 24 weeks, 87% had HIV RNA <400 copies/mL, and 74% versus 71% at baseline had undetectable (HIV RNA <50 copies/mL) viral load (ITT; M=F). Treatment-emergent AEs were infrequent (≤5%) with gastrointestinal complaints being the most common. At 24 weeks compared to baseline, hemoglobin (Hb) increased by a median of 0.6 g/dL (p < .001), and a decrease in creatinine clearance of 7.6 mL/min (p < .001) was observed. Fasting lipids decreased slightly (p < .02) in a subset of patients studied (n = 160). A higher percentage of patients reported being “very satisfied” with treatment and the absence of regimen side effects at 24 weeks versus baseline (p < .001). At 24 weeks, 86% of patients took ≥95% of doses versus 78% at baseline (p = .002). Conclusion: Patients switched to EFV + TDF/FTC maintained virologic suppression and the regimen was well tolerated. Patients reported increased satisfaction with treatment and fewer were bothered by side effects.     

Once-Daily Abacavir/Lamivudine/Zidovudine plus Tenofovir for the Treatment of HIV-1 Infection in Antiretroviral-NaïveSubjects: A 48-Week Pilot Study

Abstract

Purpose: To assess the safety and efficacy of a 4-drug, 3-tablet, once-daily (qd) regimen consisting of abacavir/lamivudine/zidovudine (ABC/3TC/ZDV; 2 tablets) and tenofovir (TDF) in antiretroviral-naïve patients with plasma HIV-1 RNA ?30,000 copies/mL at 48 weeks. Method: All participants received ABC/3TC/ZDV (300/150/300 mg) and TDF (300 mg) qd in this pilot, open-label, multicenter study. Intent-to-treat (ITT) analyses were conducted to evaluate virologic and immunologic efficacy. Results: Of the 123 participants enrolled, 52 (42%) prematurely discontinued study for adverse events (14), were lost to follow-up (13), had virologic nonresponse (12), and withdrew for other reasons (13). At week 48, by ITT missing=failure analysis, 41% (51/123) and 51% (63/123) of participants had plasma HIV-1 RNA <50 copies/mL and <400 copies/mL, respectively; by ITT-observed analysis, 75% (51/68) and 93% (63/68) had plasma HIV-1 RNA <50 copies/mL and <400 copies/mL, respectively; 11% (14/123) met virologic nonresponse criteria. Median week 48 change in CD4+ cell count from baseline was +127 cells/mm³. Median week 48 changes from baseline for fasting lipids were as follows: cholesterol (–9 mg/dL), HDL (+1 mg/dL), LDL (–9 mg/dL), and triglycerides (–4 mg/dL). Conclusion: A high rate of premature discontinuations contributed to the overall suboptimal virologic response to ABC/3TC/ZDV+TDF qd; however, the regimen was not associated with high rates of virologic failure previously observed with TDF+ABC/3TC.     

A Pilot,Prospective, Open-Label Simplification Study to Evaluate the Safety,Efficacy, and Pharmacokinetics of Once-Daily Lopinavir-Ritonavir Monotherapy in HIV-HCV Coinfected Patients: The MONOCO Study

Abstract

Background: A safe, effective, easy-to-dose antiretroviral therapy that minimizes hepatic complication risk is essential in optimizing HIV-HCV treatment. Nucleoside-sparing boosted protease inhibitor monotherapy may achieve this goal. Methods: A prospective, open-label pilot simplification study of once-daily lopina-vir/ritonavir (LPV/r) monotherapy in HIV-HCV coinfected patients was conducted in patients on HAART with undetectable HIV RNA for ≥6 months. The primary outcome was maintenance of HIV RNA <50 copies/mL through week 48. HIV RNA, immune measures, metabolic markers, and pharmacokinetics were assessed. Results: Twenty participants received once-daily LPV/r monotherapy. Mean baseline age was 46.9 years and CD4 467 cells/L. By per protocol analysis, 71.4% (95% CI, 45.4-88.3) remained on once-daily LPV/r monotherapy with virologic suppression at week 48. Virologic breakthrough (HIV RNA >50 copies/mL on 2 consecutive measures) occurred in 7 patients (mean standard error [SE] time to breakthrough, 38.3 [4.8] weeks). Resuppression occurred with improved adherence in 2 partici-pants and improved adherence plus addition of nucleosides in 2 others. LPV C ^min was <1 mg/L in 8 patients and was associated with virologic breakthrough in 2 cases but with no development of resistance. No clinically significant changes in CD4, lipids, or glucose were noted. Three participants developed transient ≥5-fold liver enzyme elevations. None of 9 severe adverse events were LPV/r- or liver-related. Six discontinued participation for withdrawal of consent (n=1), poor adherence (n=3), or drug intolerance (n=2). Conclusions: Once-daily LPV/r monotherapy in HIV-HCV coinfected individuals offers a safe and effective approach to the management of the HIV infection, with a predictable pharmacokinetic profile.