Final analysis of the Trilège induction-maintenance trial: results at 18 months

BACKGROUND

First results of Trilège demonstrated that the strategy of less intensive antiviral therapy is less effective than continuation of triple-drug therapy.

OBJECTIVE

To compare the final number of failures at month 18 and to study viral dynamics in patients experiencing a virological failure.

DESIGN

Longitudinal follow-up from a randomized controlled trial.

SETTING

Forty-three AIDS clinical-trial units.

PATIENTS

A total of 279 HIV-1 infected adults randomized in Trilège.

MEASUREMENTS

Analysis of recurrent values of HIV RNA > 500 copies/ml beyond time to virologic failure.

RESULTS

A total of 83 patients experienced virological failure by month 18; 10 in the zidovudine (ZDV) + lamivudine (3TC) + indinavir (IDV) arm, 46 in the ZDV + 3TC arm, and 27 in the ZDV + IDV arm, confirming previous results. Whatever the treatment ultimately received, 87% of patients had an HIV RNA < 500 copies/ml at month 18 with no statistical difference between randomized arms. Patients experiencing a failure in the triple-drug regimen had a greater tendency to maintain HIV RNA > 500 copies/ml beyond the time of virological failure than patients in both less intensive treatment groups who experienced failure. Lower levels of HIV RNA at failure and reinitiating of either the original triple-drug regimen or a new combination of nucleoside analogue reverse transcriptase inhibitors and protease inhibitors were associated with lower hazard ratios for developing recurrent HIV RNA > 500 copies/ml.

CONCLUSION

Results confirmed the failure of a less intensive regimen to maintain patients with a viral suppression (HIV RNA < 500 copies/ml). Although there is a lower incidence of failure in the triple-drug regimen, randomization to a less intensive regimen of ZDV + 3TC or ZDV + IDV was not detrimental, as treatment modification, either to the original triple regimen, or a different regimen was successful.

Concentration-controlled compared with conventional antiretroviral therapy for HIV infection

OBJECTIVES

To demonstrate the feasibility of a concentration-controlled approach to combination antiretroviral therapy, and to compare the virological responses and safety of this strategy versus conventional fixed-dose therapy.

DESIGN

A prospective, randomized, 52 week, open-label trial of concentration-controlled compared with conventional dose zidovudine, lamivudine, and indinavir therapy conduced in a university-based general clinical research center in the United States.

PATIENTS

Forty antiretroviral-naive individuals with plasma HIV-RNA levels > 5000 copies/ml.

INTERVENTIONS

Zidovudine, lamivudine, and indinavir plasma concentrations were measured in all participants. Doses were adjusted in those assigned to concentration-controlled therapy to achieve levels equal to or greater than target values.

MAIN OUTCOME MEASURES

The proportion of patients who achieved the desired drug concentrations, the proportion of patients with HIV-RNA levels < 50 copies/ml at week 52, and safety and tolerance in the concentration-controlled versus conventional therapy arms.

RESULTS

Significantly more concentration-controlled recipients achieved the desired concentration targets for all three drugs: 15 of 16 concentration-controlled recipients compared with nine of 17 conventional recipients (P = 0.017) had HIV-RNA levels < 50 copies/ml at week 52. No difference was observed in the occurrence of drug-related clinical events or laboratory abnormalities between the two treatment arms.

CONCLUSION

Concentration-controlled therapy implemented simultaneously for three antiretroviral agents was feasible, as well tolerated as conventional therapy, and resulted in a greater proportion of recipients with HIV-RNA levels < 50 copies/ml after 52 weeks. These findings provide a scientific basis to challenge the accepted practice of administering the same dose of antiretroviral agents to all adults, ignoring the concentrations actually achieved.

[Acute coronary syndromes in patients treated with HIV protease inhibitors]

INTRODUCTION

Cardiovascular complications occurring in patients infected by the human immunodeficient virus (HIV) have considerably changed since the appearance, in April 1996, of highly active antiretroviral tri-therapy (HAART), associating reverse transcriptase and protease HIV-1 inhibitors. The spectacular efficacy of anti-proteases has led to the almost complete disappearance of these opportunistic complications. However, in May 1998, acute coronary accidents were reported in the literature, thus questioning the possible responsibility of antiprotease treatment in the occurrence of accelerated atheroma.

METHOD

We report a series of 8 seropositive patients in whom an acute coronary event had occurred between February 1997 and February 1999.

RESULTS

The patients were young and all exhibited cardiovascular risk factors (smoking, dyslipidemia) and were treated with HIV-1 protease inhibitors. Six patients presented myocardial infarction, one patient unstable angina and one patient effort angina.

COMMENTS

A rise in triglycerides was observed principally on ingestion of ritonavir and a rise in cholesterol and LDL-cholesterol with all the antiprotease agents. Glucose intolerance was observed with indinavir. The occurrence of acute coronary events appeared to be related to antiprotease treatment (at the origin of metabolic disorders, endothelial dysfunction...), although it was impossible to say whether the antiprotease agents were responsible for the early atheroma or whether they simply contributed to the event. The coronary lesions were characterized by their number (single artery) and their topography (proximal or median). Nelfinavir may carry less cardiovascular risks than the other antiproteases. Mean term prognosis was relatively good, after therapeutic adjustment (change in antiprotease, strategic measures against cardiovascular risk factors, introduction of anti-anginal treatment...).

CONCLUSION

Larger and longer studies would help to specify the role of antiproteases in the occurrence of early coronary events. Rigorous monitoring (lipid and glucose measurements, tests to search for myocardial infarction,..) together with the development of new antiretroviral molecules would reduce the number of coronary events in this type of patient.

HIV protease inhibitors are potent anti-angiogenic molecules and promote regression of Kaposi sarcoma

Treatment with HIV-1 protease inhibitors (PI) is associated with a reduced incidence or regression of Kaposi sarcoma (KS). Here we show that systemic administration of the PIs indinavir or saquinavir to nude mice blocks the development and induces regression of angioproliferative KS-like lesions promoted by primary human KS cells, basic fibroblast growth factor (bFGF), or bFGF and vascular endothelial growth factor (VEGF) combined. These PIs also block bFGF or VEGF-induced angiogenesis in the chorioallantoic membrane assay with a potency similar to paclitaxel (Taxol). These effects are mediated by the inhibition of endothelial- and KS-cell invasion and of matrix metalloproteinase-2 proteolytic activation by PIs at concentrations present in plasma of treated individuals. As PIs also inhibit the in vivo growth and invasion of an angiogenic tumor-cell line, these data indicate that PIs are potent anti-angiogenic and anti-tumor molecules that might be used in treating non-HIV KS and in other HIV-associated tumors.

Targeted delivery of indinavir to HIV-1 primary reservoirs with immunoliposomes

The tissue distribution of indinavir, free or incorporated into sterically stabilized anti-HLA-DR immunoliposomes, has been evaluated after a single subcutaneous injection to C3H mice. Administration of free indinavir resulted in low drug levels in lymphoid organs. In contrast, sterically stabilized anti-HLA-DR immunoliposomes were very efficient in delivering high concentrations of indinavir to lymphoid tissues for at least 15 days post-injection increasing by up to 126 times the drug accumulation in lymph nodes. The efficacy of free and immunoliposomal indinavir has been evaluated in vitro. Results showed that immunoliposomal indinavir was as efficient as the free agent to inhibit HIV-1 replication in cultured cells. The toxicity and immunogenicity of repeated administrations of liposomal formulations have also been investigated in rodents. No significant differences in the levels of hepatic enzymes of mice treated with free or liposomal indinavir were observed when compared to baseline and control untreated mice. Furthermore, histopathological studies revealed no significant damage to liver and spleen when compared to the control group. Liposomes bearing Fab' fragments were 2.3-fold less immunogenic than liposomes bearing the entire IgG. Incorporation of antiviral agents into sterically stabilized immunoliposomes could represent a novel therapeutic strategy to target specifically HIV reservoirs and treat more efficiently this retroviral infection.

Differences in the detection of three HIV-1 protease inhibitors in non-blood compartments: clinical correlations

PURPOSE

To study the presence of three HIV-1 protease inhibitors (PIs) in the cerebrospinal fluid (CSF), semen, and lymph nodes and to assess the correlations with residual viral replication in these compartments.

METHOD

We performed a cross-sectional analysis of sanctuary samples from 41 HIV-infected patients on stable highly active antiretroviral therapy (HAART) regimens containing indinavir, nelfinavir, or lopinavir combined with ritonavir (lopinavir/r) and a longitudinal analysis of PI levels and HIV-1 RNA in plasma and CSF of 6 additional patients on nelfinavir or lopinavir/r monotherapy (3 cases each). Plasma, CSF, semen, and a lymph node (LN) biopsy were taken on the same day. Samples were assayed for PI concentrations, HIV-1 RNA levels, and, when detectable, sequencing of the reverse transcriptase and protease genes on seminal viral RNA.

RESULTS

In the cross-sectional analysis, the CSF/plasma ratio was 0.14 for indinavir. Nelfinavir and lopinavir/r were consistently undetectable in CSF. The semen/plasma ratio was 1.9 for indinavir, 0.07 for nelfinavir, and 0.07 for lopinavir. The LN/plasma ratio was 2.07 for indinavir, 0.58 for nelfinavir, 0.21 for lopinavir, and 0.64 for ritonavir. Plasma HIV-1 RNA was <50 copies/mL in 28 patients and was detectable in 13 patients. HIV-1 RNA was <50 copies/mL in CSF samples when plasma RNA was undetectable. Three semen samples taken from patients with viremia <50 copies/mL showed detectable HIV-1 RNA with resistance mutations. HIV-1 RNA was detectable in all LNs, with no differences in patients on indinavir compared with those on nelfinavir or lopinavir/r. In the longitudinal analysis, HIV-1 RNA decreased in the plasma of the 6 patients on nelfinavir or lopinavir/r monotherapy, although CSF HIV-1 RNA decreased only in patients on lopinavir/r.

CONCLUSION

Major differences exist between PIs in terms of detection in non-blood compartments. An undetectable PI level in CSF does not rule out drug activity in the brain for lopinavir/r, although this is not the case for nelfinavir. Poor penetration of PIs in semen in some patients can lead to double nucleoside therapy in this compartment. The persistence of HIV-1 RNA in LNs does not seem to be related to PI levels in this tissue.

Successful simplification of HAART in patients with acute primary HIV infection

Aggressive treatment has been advocated for the management of primary HIV infection (PHI), but the composition and the optimal duration of therapy are still to be determined. In addition, time to undetectable viral load (VL), rate and duration of VL suppression as well as subsequent therapeutic choices remain issues widely debated. We evaluated the rate and duration of VL suppression in 12 consecutive patients with PHI given triple-drug treatment with zidovudine, lamivudine and indinavir (highly active antiretroviral therapy, HAART) at onset of the acute illness and subsequently switched to a simplified 2-NRTI-based regimen once VL suppression was maintained for at least 6 months. Throughout the study, no patient discontinued treatment because of symptoms attributed to the study medications. In the study population, undetectable VL was achieved after a median of 84 days (range: 67-135) on HAART and was maintained for a median of 194 days (range: 179-205) before simplification. After switching to simplified maintenace, undetectable VL was maintained in all patients for at least 6 months. Only one patient experienced virological failure, plasma HIV-RNA remaining suppressed for a median foliow-up of 33 months (15-54) and T-CD4+ being steadily higher than 500/mL in the remaining patients. Our results suggest that simplification of HAART in patients promptly treated during PHI and maintaining undetectable VL for at least 6 months before simplification may be a valid option capable of controlling viral replication and maintaining an optimal immunological profile for a prolonged time.

Therapeutic drug monitoring of indinavir in HIV-infected patients undergoing HAART

BACKGROUND

Therapeutic drug monitoring (TDM) of protease inhibitors (PI) is gaining increasing importance for the management of HIV-infected patients undergoing highly active antiretroviral therapy (HAART). The PI indinavir (IDV) is widely used in HAART regimens. Combinations of IDV with ritonavir (RTV) have been used to increase the plasma concentration of IDV. However, the desirable IDV concentration range in clinical practice remains to be elucidated.

PATIENTS AND METHODS

To study the value of TDM for IDV in clinical practice, a retrospective analysis of 501 plasma samples of patients treated with IDV in various dosages was performed. IDV levels were determined during routine outpatient visits. Analysis was performed by high pressure liquid chromatography (HPlC) with UV detection.

RESULTS

A widespread range of IDV plasma concentrations was seen both within and between patients. The mean IDV level during therapy with IDV 2.4 g/d was 3,260 ng/ml (95% CI: 2,903 ng/ml; 3,618 ng/ml). IDV levels at a dose of IDV 1.6 g/d in combination with RTV resulted in a mean IDV plasma concentration of 4,191 ng/ml (95% CI: 3,356 ng/ml; 5,026 ng/ml). There was no significant difference between plasma levels at the doses of 2.4 g/d and 1.6 g/d. 35 of all 130 patients treated with IDV reached only suboptimal IDV plasma concentrations below the limit of 150 ng/ml. There was no statistically significant difference between the number of patients below an IDV plasma concentration of 150 ng/ml in the various dosage regimens.

CONCLUSION

During therapy with IDV in a b.i.d. scheme, similar IDV plasma concentrations and a comparable number of patients with subinhibitory plasma concentrations were observed when compared to a therapeutic regimen with t.i.d. dosing. In this study, even at various times of plasma sampling after oral ingestion, TCM facilitated the surveillance of patients compliance.

Hepatic and intestinal contributions to pharmacokinetic interaction of indinavir with amprenavir, nelfinavir and saquinavir in rats

To elucidate the aspects of pharmacokinetic interactions among HIV protease inhibitors (PIs), we investigated the effects of indinavir (IDV) on the hepatic and intestinal first-pass metabolism of other HIV PIs, amprenavir (APV), saquinavir (SQV) and nelfinavir (NFV), in rats. After oral co-administration with IDV, the area under the concentration versus time curves (AUC) of APV, SQV and NFV increased significantly by 1.6-, 9.5- and 2.3-fold, respectively, compared with mono-administration. After intravenous administration, the AUC of APV, SQV and NFV also increased in the presence of IDV by 1.4-, 1.2- and 1.5-fold, respectively. Mean concentrations of APV, SQV and NFV in the liver extracellular fluid, measured using a liver microdialysis method, were very low compared with their Michaelis constants regardless of co-administration of IDV, suggesting that APV, SQV and NFV metabolism follows linear kinetics in the liver. This finding also indicates that metabolism of PIs depended on the metabolic clearance rate in the liver microsomes. The oral bioavailability of SQV in the presence of IDV increased markedly by 8.5-fold, and that of APV and NFV also increased by 1.2- and 1.5-fold, respectively. On the basis of the well-stirred model, the hepatic availabilities of APV, SQV and NFV in the presence of IDV increased by 1.1-, 1.4- and 1.5-fold, and the intestinal availabilities increased by 1.1-, 6.2- and 1.1-fold, respectively. These results suggest that both hepatic and intestinal metabolism were essentially involved in the interactions between IDV and other HIV PIs, and the degree of those contributions varied with each combination of HIV PIs.

Long-term efficacy and safety of ritonavir/indinavir at 400/400 mg twice a day in combination with two nucleoside reverse transcriptase inhibitors as first line antiretroviral therapy

OBJECTIVE

To determine the long-term antiretroviral efficacy and tolerability of dual protease inhibitor (PI) therapy with indinavir (IDV)/ritonavir (RTV) at 400/400 mg twice a day (BID) in combination with two nucleoside reverse trancriptase inhibitors (NRTIs).

DESIGN AND METHODS

In an open-label, uncontrolled multicentre clinical trial, antiretroviral therapy naive patients (n = 93) with a high median baseline HIV-1 RNA level of 210 000 copies/mL (range 17 000-2 943 000) and a median CD4 cell count of 195 copies/microL (range 4-656 copies/microL) were started on a regimen of either zidovudine (ZDV)/lamivudine (3TC) (49%), stavudine (d4T)/3TC (38%) or d4T/didanosine (ddI) (14%) plus RTV and IDV, each at 400 mg BID. CD4 cell counts and HIV RNA were determined at 4-week intervals for a duration of 72 weeks. Statistical analysis was performed on treatment as well as by intent to treat, where missing values were counted as failures.

RESULTS

HIV RNA levels below the limit of detection were achieved in 59.5% (< 80 copies/mL) and 63% (< 500 copies/mL) of patients according to the intent to treat analysis at week 72. In the on treatment analysis, the proportion of patients reaching an undetectable viral load was 94.5% (< 80 copies/mL) and 100% (< 500 copies/mL), respectively. Apart from diarrhoea and nausea, serum lipid abnormalities were identified as the most prominent adverse reaction. No cases of nephrotoxicity occurred during the entire observation period of 72 weeks.

CONCLUSIONS

Our results demonstrate that quadruple therapy with RTV/IDV and two NRTIs induces potent, durable and safe HIV suppression and might be particularly beneficial as a first line therapy for patients with a high baseline viral load.

Pharmacokinetic study of human immunodeficiency virus protease inhibitors used in combination with amprenavir

In an open-label, randomized, multicenter, multiple-dose pharmacokinetic study, we determined the steady-state pharmacokinetics of amprenavir with and without coadministration of indinavir, nelfinavir, or saquinavir soft gel formulation in 31 human immunodeficiency virus type 1-infected subjects. The results indicated that amprenavir plasma concentrations were decreased by saquinavir soft gel capsule (by 32% for area under the concentration-time curve at steady state [AUC(ss)] and 37% for peak plasma concentration at steady state [C(max,ss)]) and increased by indinavir (33% for AUC(ss)). Nelfinavir significantly increased amprenavir minimum drug concentration at steady state (by 189%) but did not affect amprenavir AUC(ss) or C(max,ss). Nelfinavir and saquinavir steady-state pharmacokinetics were unchanged by coadministration with amprenavir compared with the historical monotherapy data. Concentrations of indinavir, coadministered with amprenavir, in plasma decreased in both single-dose and steady-state evaluations. The changes in amprenavir steady-state pharmacokinetic parameters, relative to those for amprenavir alone, were not consistent among protease inhibitors, nor were the changes consistent with potential interactions in CYP3A4 metabolism or P-glycoprotein transport. No dose adjustment of either protease inhibitor in any of the combinations studied is needed.

Ritonavir/saquinavir plus one nucleoside reverse transcriptase inhibitor (NRTI) versus indinavir plus two NRTIs in protease inhibitor-naive HIV-1-infected adults (IRIS study)

OBJECTIVES

To compare the efficacy, tolerability and safety of a ritonavir 400 mg/saquinavir hard gel fomulation 400 mg twice daily versus an indinavir 800 mg once every 8 h containing first-line protease inhibitor (PI) treatment regimen.

METHODS

Open, randomized, multicentre clinical trial. PI-naive patients received either ritonavir/saquinavir and one nucleoside reverse transcriptase inhibitor (NRTI) or indinavir and two NRTIs. Intention-to-treat (ITT) and on-treatment (OT) analyses were performed.

RESULTS

The baseline characteristics of the study participants were similar in both arms, 67 patients (37%) were naive to antiretroviral treatment. The proportion of patients who achieved a plasma viral load below the level of detection of 400 copies/ml at week 48 was 43% (39/90) in the ritonavir/saquinavir arm and 63% (57/90) in the indinavir arm (P=0.005, I

Anti-human immunodeficiency virus drugs are ineffective against Pneumocystis carinii in vitro and in vivo

Human immunodeficiency virus (HIV) protease inhibitors (PIs) recently have been reported to be active against Pneumocystis carinii in cell culture. Twelve anti-HIV drugs were analyzed for their effects against rat P. carinii by an ATP cytotoxicity assay. Indinavir and saquinavir exhibited slight anti-P. carinii activity at concentrations above those that can be clinically achieved in serum; other PIs and nucleoside and nonnucleoside reverse-transcriptase inhibitors were inactive against the organism. Anti-HIV drugs, alone or in combination, did not materially reduce the organism count in the treatment of P. carinii pneumonia in immunosuppressed mice. Thus, anti-HIV drugs have little or no activity against P. carinii in these in vitro and in vivo systems. Caution should be used when interpreting reports of the susceptibility of P. carinii to anti-HIV drugs on the basis of in vitro testing only.

Limited patient adherence to highly active antiretroviral therapy for HIV-1 infection in an observational cohort study

BACKGROUND

Adherence to highly active antiretroviral therapy (HAART) for human immunodeficiency syndrome type 1 (HIV-1) infection is essential to sustain viral suppression and prevent drug resistance. We investigated adherence to HAART among patients in a clinical cohort study.

METHODS

Patients receiving HAART had their plasma concentrations of protease inhibitors or nevirapine measured and completed a questionnaire on adherence. We determined the percentage of patients who reported taking all antiretroviral medication on time and according to dietary instructions in the past week. Drug exposure was compared between patients reporting deviation from their regimen and fully adherent patients. Among patients who received HAART for at least 24 weeks, we assessed the association between adherence and virologic outcome.

RESULTS

A total of 224 of 261 eligible patients completed a questionnaire. Forty-seven percent reported taking all antiretroviral medication on time and according to dietary instructions. Patients who reported deviation from their regimen showed lower drug exposure compared with fully adherent patients (median concentration ratio, 0.81 vs 1.07; P =.001). Among those receiving HAART for at least 24 weeks, patients reporting deviation from their regimen were less likely to have plasma HIV-1 RNA levels below 500 copies/mL (adjusted odds ratio, 4.0; 95% confidence interval, 1.4-11.6) compared with fully adherent patients.

CONCLUSIONS

Only half of the patients took all antiretroviral medication in accordance with time and dietary instructions in the preceding week. Deviation from the antiretroviral regimen was associated with decreased drug exposure and a decreased likelihood of having suppressed plasma HIV-1 RNA loads. Patient adherence should remain a prime concern in the management of HIV-1 infection.

A case of flare syndrome

The authors describe a case of severe CMV retinitis in a young adult AIDS patient who recovered following first a course of ganciclovir and then HAART. Six months after the initial episode while still under successful HAART, the patient developed an acute episode of retinitis despite a persistent significant improvement in the immunological picture and a very low level of CMV reactivation. The acute episode can be related to an enhanced individual reactivity to minor CMV replication.