14th Annual Conference of the British HIV Association 23-25 April 2008, Belfast

ONCE-DAILY AND TWICE-DAILY LOPINAVIR/RITONAVIR-BASED REGIMENS PROVIDE SIMILAR VIROLOGIC RESPONSE THROUGH 48 WEEKS: RESULTS OF A META-ANALYSIS

HIV Med 2008 Apr 23-25 (Suppl 1);14:14 (abstract no. P17)

M King, L Fredrick, B da Silva, T Podsadecki and B Bernstein
Abbott, Abbott Park, IL, USA

BACKGROUND: Several studies of once-daily (QD) versus twice-daily (BID) lopinavir/ritonavir (LPV/r)-based regimens in antiretroviral (ARV)-naïve subjects have been completed, with apparently inconsistent results. We sought to synthesize results across studies via meta-analysis.

METHODS: We identified 5 studies (total n=1531) assessing efficacy of LPV/r QD versus BID for at least 48 weeks in ARV-naïve subjects: studies 056 (n=38), 418 (n=190), A5073 (n=320), ARTEMIS (n=319), and 730 (n=664). Four of 5 studies (all but A5073) had data available for a meta-analysis of the intent-to-treat (ITT) proportion with HIV-1 viral load (VL) <50 c/mL at 48 weeks. Four of 5 studies (all but ARTEMIS) had data allowing assessment of time to virologic rebound >200 c/mL.

RESULTS:The differences in week 48 ITT response (<50 c/mL) rates (QD minus BID) and 95% CIs for each study were: 056:-5% (-32% to 21%); 418:6% (-7% to 20%); 730:1% (-5% to 8%); ARTEMIS: -9% (-23% to 4%). The combined estimate (95% CI) from the meta- analysis (n=1211 subjects in 4 studies) was 0.1% (-5% to 5%). In the subset with baseline VL >100,000 copies/mL (n=547), the corresponding meta-analysis estimate (95% CI) was similar: 0.3% (-8% to 8%). In the meta-analysis of time to confirmed virologic rebound >200 c/mL (n=1212 subjects in 4 studies), the combined estimate of the hazard ratio and 95% CI (values >1 favor QD) was 0.94 (0.65, 1.36) (P=0.75). In the subset with baseline VL >100,000 c/mL (n = 601), the corresponding estimate was 1.10 (0.4, 3.07) (P=0.85).

CONCLUSIONS: A meta-analysis of over 1500 ARV-naïve subjects indicated that virologic response through 48 weeks, as measured by 2 different endpoints, is similar between QD and BID LPV/r-based regimens and is independent of baseline viral load.

2008-04-23
P17

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