[Show abstract][Hide abstract] ABSTRACT: 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.
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.
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).
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.
HIV Clinical Trials 11/2006; 7(6):324-33. DOI:10.1310/hct0706-324 · 2.14 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: A one-tablet, once-daily abacavir/lamivudine fixed-dose combination (FDC) has been recently approved to treat HIV-1 infection.
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.
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.
The FDC group had noninferior efficacy over 48 weeks to the SE group in treatment-experienced subjects with VF.
[Show abstract][Hide abstract] ABSTRACT: The long intracellular half-life of abacavir (ABC) supports its once-daily use, and this would be expected to simplify treatment if ABC could be given as part of a complete once-daily regimen. A randomized double-blind clinical trial compared the efficacy and safety of 600 mg of ABC administered once daily (n = 384) versus 300 mg of ABC administered twice daily (n = 386) in combination with 300 mg of lamivudine (3TC) and 600 mg of efavirenz (EFV) administered once daily in antiretroviral-naive patients over 48 weeks. The baseline median plasma HIV-1 RNA level was 4.89 log10 copies/mL (44% with viral load >100,000 copies/mL), and the median CD4 cell count was 262 cells/mm. ABC administered once daily was non-inferior to the twice-daily regimen, with 66% and 68% of patients in these respective treatment arms achieving a confirmed plasma HIV-1 RNA level <50 copies/mL (95% confidence interval: -8.4%, 4.9%). The ABC once-daily and twice-daily regimens were similar with respect to infrequency of virologic failure (10% vs. 8%), emergence of resistance mutations, CD4 cell increases from baseline (median, 188 vs. 200 cells/mm), safety profile, and incidence of ABC-related hypersensitivity reactions (9% vs. 7%). ABC administered once daily in combination with 3TC and EFV administered once daily was non-inferior to the ABC twice-daily dosing schedule when combined with 3TC and EFV over 48 weeks.
[Show abstract][Hide abstract] ABSTRACT: Zidovudine, lamivudine, and efavirenz comprise a highly effective and well-tolerated triple regimen for antiretroviral-naive patients. Evaluating other unique nucleoside reverse-transcriptase inhibitor (NRTI) combinations for long-term viral suppression is desirable.
This multicenter, randomized, double-blind noninferiority clinical trial compared the efficacy and safety of abacavir with that of zidovudine plus lamivudine and efavirenz in 649 antiretroviral-naive HIV-infected patients. The primary objective was a comparison of proportions of patients achieving plasma HIV-1 RNA levels <or=50 copies/mL through week 48 of the study.
At study week 48, 70% of patients in the abacavir group, compared with 69% in the zidovudine group, maintained confirmed plasma HIV-1 RNA levels of <or=50 copies/mL (in the intent-to-treat exposed population). Virologic failure was infrequent (6% in the abacavir group and 4% in the zidovudine group). There was a significant CD4(+) cell response (209 cells/mm(3) in the abacavir group and 155 cells/mm(3) in the zidovudine group). Safety profiles were as expected.
Abacavir provided an effective and durable antiretroviral response that was noninferior to zidovudine, when combined with lamivudine and efavirenz.