First-line Highly Active Antiretroviral Regimens in 2001–2002 in the French Hospital Database on HIV: Combination Prescribed and Biological Outcomes

Introduction

We compared biological outcomes in anti-retroviral-naive patients with viral load (VL) >5,000 copies/ml starting combivir-based, three-drug highly active antiretroviral therapy regimens in 2001–2002 according to the third component, namely abacavir (ABC), nelfinavir (NFV), indinavir/ritonavir (IDV/r), lopinavir/ritonavir (LPV/r), nevirapine (NVP) or efavirenz (EFV).

Methods

We evaluated virological response (HIV RNA <500 copies/ml) and immunological response (increase of ≥50 CD4+ T-cells/u, l) separately in patients with baseline VL <100,000 copies/ml ( n=992) and ≥100,000 copies/ml ( n=1,048). Hazard ratios (HR) were calculated with Cox models stratified for quintiles of propensity scores, estimated by multinomial regression from baseline characteristics.

Results

Median follow up was 19 months. EFV had better virological efficacy than NFV and IDV/r among patients with baseline VL <100,000 copies/ml, with respective HRs of 0.71 and 0.72, compared with 0.81 for NVP, 0.89 for ABC and 0.99 for LPV/r. The immunological efficacy of EFV was lower than that of LPV/r (1.37) and similar to that of NFV (0.96), IDV/r (0.81), NVP (1.08) and ABC (1.04). Among patients with baseline VL ≥100,000 copies/ml, the virological efficacy of EFV was similar to that of NVP (0.90) and LPV/r (0.97) and better than that of NFV (0.62), ABC (0.75) and IDV/r (0.78). The immunological results found in these patients were similar to those observed in patients with baseline VL <100,000 copies/ml.

Conclusions

For first-line therapy, in this observational setting, EFV, LPV/r and NVP, when added to the combivir backbone, were more likely to drive viral load <500 copies/ml. LPV/r showed the best immunological effectiveness.

Boosted versus Unboosted Indinavir with Zidovudine and Lamivudine in Nucleoside Pre-Treated Patients: A Randomized, Open-Label Trial with 112 Weeks of Follow-Up (HIV-Nat 005)

Introduction

The use of HIV protease inhibitors (PIs) in a ritonavir (RTV)-boosted form is now common. However, randomized data comparing boosted with unboosted PI strategies are scarce.

Methods

This randomized, open-label trial compared indinavir (IDV) 800 mg three times daily with IDV/RTV 800/100 mg twice daily, both given with zidovudine (AZT)/lamivudine (3TC) twice daily in individuals with at least 3 months previous AZT experience. The primary endpoint was the time-weighted average change in HIV RNA from baseline. Designed as a 48-week study, follow-up continued until week 112. Primary analysis is by intention to treat.

Results

One hundred and three patients commenced therapy and are included in the analysis. Patients had a median of 29 months past nucleoside reverse transcriptase inhibitor (NRTI) exposure. Baseline median (interquartile range) log10 HIV RNA was 4.0 (3.3–4.5) and CD4+T-cell count 166 (40–323) cells/μl. After 112-weeks of study there was no significant difference observed between arms in the mean (sd) change in time-weighted average HIV RNA from baseline (-1.6 [1.1] HIV RNA copies/week/ml three times daily arm; -1.4 [1.1] HIV RNA copies/week/ml twice daily arm; P=0.3). Both arms were associated with substantial toxicity expressed as serious adverse events and study drug interruptions. The twice daily arm experienced greater dyslipidaemia. Mean (sd) changes in time-weighted CD4+ T-cell count from baseline were similar [88 (84) cells/week/μl three times daily arm; 70 [109] cells/week/μl twice daily arm; P=0.3).

Conclusions

RTV-boosted IDV 800/100 mg twice daily demonstrated comparable efficacy to unboosted IDV 800mg three times daily dosing. Both regimens were associated with substantial toxicity. Use of lower doses of RTV-boosted IDV may result in better tolerability without loss of efficacy and warrant further research.

Pharmacokinetics of Reduced-Dose Indinavir/Ritonavir 400/100 Mg Twice Daily in HIV-1-Infected Thai Patients

Objective

To study the pharmacokinetics of indinavir/ ritonavir 400/100 mg twice daily in antiretroviral-naive patients at Srinagarind Hospital in Khon Kaen, Thailand.

Methods

This was a steady-state, open-label pharmacokinetic study of 19 patients. A 12 h pharmacokinetic curve was recorded after an overnight fast. Plasma levels of indinavir and ritonavir were determined by a validated HPLC method. Virological failure was defined according to the most recent US Department of Health and Human Services guidelines as a viral load above 400 copies/ml at week 24.

Results

Median baseline values for CD4 and viral load were 13 cells/mm3 and 167000 copies/ml, respectively. The median (interquartile ranges) for indinavir AUC, Cmax and Cmin were 18.1 (15.3–23.8) mg/l•h, 4.1 (3.6–4.8) mg/l and 0.17 (0.12–0.30) mg/l, respectively. These values represent 37%, 39% and 24% of the AUC, Cmax and Cmin values found, respectively, for the indinavir/ritonavir 800/100 mg dose in HIV-1-infected Thai patients. Short-term virological response was satisfactory. There were three subjects with an indinavir Cmin below the target value of 0.10 mg/l, of whom one had virological failure (33%). Among the other 16 subjects with an indinavir Cmin above 0.10 mg/l, there was also one virological failure (6%) ( P=0.30).

Conclusions

Indinavir exposure in this reduced-dose regimen of 400 mg with 100 mg ritonavir twice daily was more than dose-proportionally lower than previously observed with the indinavir/ritonavir 800/100 mg twice daily regimen. Therapeutic Cmin levels of indinavir were achieved in >80% of the subjects and short-term virological response was satisfactory in this cohort of patients starting highly active antiretroviral therapy at an advanced disease stage with high baseline viral loads.