Once-daily abacavir/lamivudine and ritonavir-boosted atazanavir for the treatment of HIV-1 infection in antiretroviral-naïve patients: a 48-week pilot study.
OBJECTIVE
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.


METHODS
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 >or= 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.


CONCLUSIONS
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.
Elion
Richard
R
George Washington University, Washington, DC, USA. relion@wwc.org
Dejesus
Edwin
E
Sension
Michael
M
Berger
Daniel
D
Towner
William
W
Richmond
Gary
G
St Clair
Marty
M
Yau
Linda
L
Ha
Belinda
B
D000328:Adult; D000368:Aged; D019380:Anti-HIV Agents / Q000008:administration & dosage / Q000627:therapeutic use; D000069446:Atazanavir Sulfate; D015224:Dideoxynucleosides / Q000008:administration & dosage / Q000627:therapeutic use*; D004334:Drug Administration Schedule; D004359:Drug Therapy, Combination; D005260:Female; D015658:HIV Infections / Q000188:drug therapy*; D006801:Humans; D019259:Lamivudine / Q000008:administration & dosage / Q000627:therapeutic use*; D008297:Male; D008875:Middle Aged; D009842:Oligopeptides / Q000008:administration & dosage / Q000627:therapeutic use*; D010865:Pilot Projects; D011725:Pyridines / Q000008:administration & dosage / Q000627:therapeutic use*; D019438:Ritonavir / Q000008:administration & dosage / Q000627:therapeutic use*; D000099227:Abacavir
D019380:Anti-HIV Agents; D000069446:Atazanavir Sulfate; D015224:Dideoxynucleosides; D019259:Lamivudine; D009842:Oligopeptides; D011725:Pyridines; D019438:Ritonavir; D000099227:Abacavir