Efficacy, adherence and tolerability of once daily tenofovir DF-containing antiretroviral therapy in former injecting drug users with HIV-1 receiving opiate treatment: results of a 48-week open-label study.

OBJECTIVE: To assess efficacy, adherence and tolerability of once daily antiretroviral therapy containing tenofovir disoproxil fumarate (DF) 300 mg in HIV-1-infected former injecting drug users receiving opiate treatment (IVDU). METHODS: European, 48-week, open-label, single-arm, multicenter study. Patients were either antiretroviral therapy-naive, restarting therapy after treatment discontinuation without prior virological failure or switching from existing stable treatment. RESULTS: Sixty-seven patients were enrolled in the study and 41 patients completed treatment. In the primary analysis (intent-to-treat missing=failure) at week 48, 34% of patients (23/67; 95% CI: 23%-47%) had plasma HIV-1 RNA <50 copies/mL. Using an intent-to-treat missing=excluded approach, the week 48 proportion of patients with plasma HIV-1 RNA <50 copies/mL increased to 56% (23/41; 95% CI: 40%-72%). Mean (standard deviation) increase from baseline in CD4+ cell count at week 48 was 176 (242) cells/mm(3). Although self-reported adherence appeared high, there were high levels of missing data and adherence results should be treated with caution. No new safety issues were identified. CONCLUSIONS: Levels of missing data were high in this difficult-to-treat population, but potent antiretroviral suppression was achieved in a substantial proportion of HIV-infected IVDU-patients.

Human immunodeficiency virus type-1 group M quasispecies evolution: diversity and divergence in patients co-infected with active tuberculosis.

The evolution of intra-host human immunodeficiency virus type 1 (HIV-1) quasispecies prior and after treating active tuberculosis (TB) with chemotherapy in HIV-1/TB patients was assessed. Two time points HIV-1 quasispecies were evaluated by comparing HIV-1-infected patients with active tuberculosis (HIV-1/TB) and HIV-1-infected patients without tuberculosis (HIV-1/non-TB). Plasma samples were obtained from the Frankfurt HIV cohort, and HIV-1 RNA was isolated. C2V5 env was amplified by PCR and molecular cloning was performed. Eight to twenty-five clones were sequenced from each patient. Various phylogenetic analyses were performed. We found a significant increase in diversity and divergence in HIV-1/TB compared to the HIV-1/non-TB. For HIV-1/TB, the average rate of evolution of C2V5 env was higher than previous reports (2.4 × 10(-4) substitution/site/day). Two groups of HIV-1/TB were observed based on the rate of HIV-1 evolution and coreceptor usage: A fast evolving R5-tropic dominating group and a relatively slowly evolving X4 group. The results demonstrated that active TB has an impact on HIV-1 viral diversity and divergence over time. The influence of active TB on longitudinal evolution of HIV-1 may be predominant for R5 viruses.

Mutations in the C-terminal region of the HIV-1 reverse transcriptase and their correlation with drug resistance associated mutations and antiviral treatment.

OBJECTIVE: replication of HIV-1 after cell entry is essentially dependent on the reverse transcriptase (RT). Antiretroviral drugs impairing the function of the RT currently aim at the polymerase subunit. One reason for failure of antiretroviral treatment is the evolvement of resistance-associated mutations in the viral genome. For RT inhibitors, almost all identified mutations are located within the polymerase; therefore, general genotyping confines to investigate this subunit. Recently several studies have shown that substitutions within the RNase H and the connection domain increase antiviral drug-resistance in vitro, and some of them are present in patient isolates. AIM: the aim of the present study was to investigate the prevalence of these substitutions and their association with mutations in the polymerase domain arising during antiretroviral treatment. MATERIAL AND METHODS: we performed genotypic analyzes on seventy-four virus isolates derived from treated and untreated patients, followed at the HIV Centre of the Johann Wolfgang Goethe University Hospital (Frankfurt/Main, Germany). We subsequently ana?lysed the different substitutions in the c-terminal region to evaluate whether there were associations with each other, n-terminal substitutions or with antiretroviral treatment. RESULTS: We identified several primer grip substitutions, but almost all of them were located in the connection domain. This is consistent with other in-vivo studies, in which especially the primer grip residues located in the RNase H were unvaried. Furthermore, we identified other substitutions in the connection domain and in the RNase H. Especially E399D seemed to be associated with an antiretroviral treatment and N-terminal resistance-delivering mutations. CONCLUSION: some of the identified substitutions were associated with antiviral treatment and drug resistance-associated mutations. Due to the low prevalence of C-terminal mutations and as only a few of them could be associated with antiviral treatment and N-terminal resistance-delivering mutations, we would not recommend routinely testing of the C-terminal RT region.

The influence of HAART on the efficacy and safety of pegylated interferon and ribavirin therapy for the treatment of chronic HCV infection in HIV-positive Individuals.

OBJECTIVE: This study was performed to investigate the impact of HAART versus no HAART and nucleoside free versus nucleoside containing HAART on the efficacy and safety of pegylated interferon and ribavirin therapy for the treatment of chronic HCV infection in HIV/HCV co-infected patients. In addition a control group of HCV mono-infected patients undergoing anti-HCV therapy was evaluated. METHODS: Multicenter, partially randomized, controlled clinical trial. HIV-negative and -positive patients with chronic HCV infection were treated with pegylated interferon alfa-2a and ribavirin (800 - 1200 mg/day) for 24 - 48 weeks in one of four treatment arms: HIV-negative (A), HIV-positive without HAART (B) and HIV-positive on HAART (C). Patients within arm C were randomized to receive open label either a nucleoside containing (C1) or a nucleoside free HAART (C2). RESULTS: 168 patients were available for analysis. By intent-to-treat analysis similar sustained virological response rates (SVR, negative HCV-RNA 24 weeks after the end of therapy) were observed comparing HIV-negative and -positive patients (54% vs. 54%, p = 1.000). Among HIV-positive patients SVR rates were similar between patients off and on HAART (57% vs. 52%, p = 0.708). Higher SVR rates were observed in patients on a nucleoside free HAART compared to patients on a nucleoside containing HAART, though confounding could not be ruled out and in the intent-to-treat analysis the difference was not statistically significant (64% vs. 46%, p = 0.209). CONCLUSIONS: Similar response rates for HCV therapy can be achieved in HIV-positive and -negative patients. Patients on nucleoside free HAART reached at least equal rates of sustained virological response compared to patients on standard HAART.

Factors associated with viral rebound among highly treatment-experienced HIV-positive patients who have achieved viral suppression.

OBJECTIVE: More and more highly treatment-experienced patients are achieving viral suppression. However, the durability of suppression remains unclear. METHODS: Patients from Royal Free Hospital (London, UK) and JW Goethe University Hospital (Frankfurt, Germany) who had failed > or = 1 antiretroviral (ARV) regimen in all three main drug classes and > or = 3 previous ARV regimens and subsequently achieved viral load < 50 HIV-1 RNA copies/mL were included. They were followed until stopping pre-combination antiretroviral therapy, end of follow-up or viral rebound (two viral loads >400 copies/mL). RESULTS: Two hundred and forty-seven patients contributed 723 person-years and 114 viral rebounds [rate=15.8 per 100 person-years; 95% confidence interval (CI) 12.9-18.7]. More recent calendar years of viral suppression [relative risk (RR)=0.90 per year later; 95% CI 0.81-1.00; P=0.05] and greater number of ARVs in the regimen not previously failed (RR=0.78 per 1 ARV more; 95% CI 0.65-0.95; P=0.01) were associated with lower viral rebound rates. At 0-1, 1-2, 2-3 and > 3 years after achieving suppression, the rebound rates were 30.9, 9.2, 4.3 and 3.5 per 100 person-years, respectively. Compared to 0-1 years, the adjusted RRs (95% CIs) after 1-2, 2-3 and > 3 years were 0.33 (0.18-0.58), 0.21 (0.09-0.48) and 0.14 (0.06-0.33), respectively (P<0.0001). CONCLUSIONS: Although rebound rates are high, especially in the first year after viral suppression, this risk reduces substantially if highly treatment-experienced patients can maintain viral suppression.

Switch to efavirenz (EFV) after protease-inhibitor (PI)-failure: explorative analysis of outcome by baseline viral VS tolerability failure.

The aim of this database analysis was to investigate the efficacy and safety of efavirenz (EFV)-based highly active antiretroviral therapy (HAART) after switching from failed protease inhibitor (PI)- and boosted PI (PI/r)-based regimens. Data were analyzed from 17 adult patients previously treated with a PI-based HAART with substitution of PI with EFV because of virologic failure and from 14 patients previously treated with a PI-based HAART, with substitution of PI due to tolerability issues. Of 17 patients who switched therapy because of virologic failure, 5 patients maintained EFV-therapy for more than 1 year. In 11/17 patients, EFV-based HAART was discontinued during follow-up and one patient was lost to follow-up. Reasons for discontinuation were: virologic failure in 4, adverse events in 6 (5 CNS-adverse events and 1 rash) and non-compliance in 1 of 17 patients. Of 14 patients who stopped PI-therapy and switched to EFV due to tolerability issues, 6 patients maintained EFV-therapy for more than 1 year. In 8/14 patients EFV-based HAART was discontinued during follow-up. Reasons for discontinuation were: virologic failure in 3, adverse events in 3 (2 CNS-adverse events and 1 patient had rash) and non-compliance in 2 of 14 patients. Instable switch to an EFV-based regimen due to virologic failure or toxicity reasons with a boosted or unboosted PI does not show significant differences but outcome was worse than had been described previously for stable switch settings, likely due to multiple prior virologic failures in many patients.

Predicting the duration of antiviral treatment needed to suppress plasma HIV-1 RNA.

Effective therapeutic interventions and clinical care of adults infected with HIV-1 require an understanding of factors that influence time of response to antiretroviral therapy. We have studied a cohort of 118 HIV-1-infected subjects naive to antiretroviral therapy and have correlated the time of response to treatment with a series of virological and immunological measures, including levels of viral load in blood and lymph node, percent of CD4 T cells in lymph nodes, and CD4 T-cell count in blood at study entry. Suppression of viremia below the limit of detection, 50 HIV-1 RNA copies/mL of plasma, served as a benchmark for a successful virological response. We employed these correlations to predict the length of treatment required to attain a virological response in each patient. Baseline plasma viremia emerged as the factor most tightly correlated with the duration of treatment required, allowing us to estimate the required time as a function of this one measure.

First case of successful allogeneic stem cell transplantation in an HIV-patient who acquired severe aplastic anemia.

We report on the first successful allogeneic stem cell transplantation (SCT) in an HIV-infected patient with severe aplastic anemia (SAA) per- formed at a tertiary care institution. Highly active antiretroviral therapy (HAART) was administered until transplantation and restarted 34 days later with sustained virological response. The patient did however develop a rapid rise in HIV load during the interruption of HAART associated with an acute febrile illness. Due to the extended period between the onset of SAA until SCT, the posttransplant course was complicated by bacterial infections. Stage two skin GvHD, but no AIDS-defining opportunistic diseases were experienced. Neutrophils recovered to >0.5/nL on day +18 and the CD4 count reached 250/microL on day +71 and >500/microL on day +182. The patient is in good condition with an ECOG score of 0 twelve months after transplantation. This report demonstrates the feasibility of allogeneic stem cell transplantation in the HIV setting.

Dose reduction effective in alleviating symptoms of saquinavir toxicity.

Gastrointestinal intolerance is a limitation of boosted saquinavir antiretroviral treatment. We present three HIV-infected individuals whose severe toxicity symptoms started directly after initiation of a standard dose saquinavir hard-gel capsule-containing regimen (saquinavir/ritonavir 1000/100 mg). All patients underwent immediate 12 h pharmacokinetic (PK) assessment and showed extraordinarily high saquinavir plasma exposure. All three patients did not recover until the saquinavir exposure was decreased. This pilot case study anticipates a new concept of 'direct PK'-guided individual dose interventions under close viral load monitoring. Two major reasons for symptomatic saquinavir overexposure were defined: impaired liver function in a chronic hepatitis C virus co-infected individual at normal liver performance parameters and a delayed cytochrome p450 enzyme autoinduction. Overexposure seems to be an independent intolerance factor. Although delayed autoinduction is not well established as a reason for adverse events in saquinavir therapy, this observation may be confirmed in the near future by increased use.

Consensus recommendation from a group of German experts for the use of enfuvirtide in heavily pretreated HIV patients.

BACKGROUND: The EU approval of enfuvirtide (Fuzeon) was granted in May 2003 on the basis of the 48-week data from the TORO 1 and TORO 2 studies. Enfuvirtide is licensed for use in pretreated HIV patients experienced with three classes of drugs who exhibited treatment failure or who have shown intolerance to previous antiretroviral treatment regimens. Recent studies with the new protease inhibitors tipranavir and darunavir (RESIST and POWER studies) showed that a high proportion of heavily pretreated HIV patients achieve a viral load reduction to below the limit of detection when treated with enfuvirtide plus one of these new ritonavir-boosted protease inhibitors and an optimised background treatment regimen. The International AIDS Society (IAS-USA Panel) has recently updated its treatment guidelines in view of these new data and recommends the use of an antiretroviral treatment regimen containing at least two active drugs, one of which that has a new mechanism of action, for HIV patients who have been heavily pretreated. A new treatment goal has also emerged for heavily pretreated patients with advanced HIV disease: reduction of the viral load to below the detection limit of 50 copies/ml. The IAS concluded that the likelihood of achieving this treatment goal is higher when enfuvirtide is selected as one of the two active drugs. OBJECTIVE: A panel of German experts convened to discuss the currently available data and to incorporate them into the updated German consensus recommendations for the use of enfuvirtide when switching treatment in heavily pretreated HIV patients. METHODS: The consensus recommendations are based on published data from controlled, randomised clinical studies and on the expert opinions of the discussants. RESULTS AND CONCLUSIONS: The consensus recommendations were developed to provide practice-relevant standardised recommendations for selecting suitable candidates for enfuvirtide therapy and for their management. Aspects including predictive prognostic factors, disease stage, selection of the optimised background regimen, early indicators of a response to enfuvirtide, as well as accompanying educational measures treatment were considered. New protease inhibitors or other remaining active drugs should be used together with enfuvirtide in heavily pretreated patients in order to enable at least two active drugs to be included in such a salvage regimen.

Pharmacokinetics and tolerability of a combination of indinavir, lopinavir and ritonavir in multiply pretreated HIV-1 infected adults.

OBJECTIVES: The authors evaluated the pharmacokinetics and tolerability of indinavir/lopinavir/ritonavir in a protease inhibitor only combination. METHODS: Plasma drug levels of patients taking indinavir/lopinavir/ritonavir 800/400/100mg twice daily (n = 24, group 1) were compared to patients taking either lopinavir/ritonavir 400/100mg (n = 35, group2) or indinavir/ritonavir 800/100mg (n = 33, group3) twice daily plus nucleos(t)ide reverse transcriptase inhibitors (NRTI). Steady-state drug concentrations were measured by LC/MS/MS. Minimum and maximum concentrations (C subsetmin, C subsetmax), area under the concentration-time curve (AUC subset0-12h), total clearance (CL subsettot) and half-life (t1/2) were calculated. HIV viral load, CD4 cell count and adverse events causing early termination of therapy were correlated over a period of 48 weeks. RESULTS: Plasma levels of lopinavir/ritonavir were significantly enhanced when combined with indinavir compared to a regimen of lopinavir/ritonavir+NRTI: Mean lopinavir AUC subset(0-12h) 80,912 ng*h/mL vs. 60,548 ng*h/mL; C subsetmin 4,633 ng/mL vs. 3,258 ng/mL; C subsetmax 8,023 ng/mL vs. 6,710 ng/mL. Mean ritonavir AUC(0-12h) 6,907 ng*h/mL vs. 3,467 ng*h/mL; Cmin 220 ng/mL vs. 125 ng/mL; C subsetmax 1,059 ng/mL vs. 522 ng/mL. Indinavir levels were comparable for both indinavir containing regimen. A significantly smaller number of patients stopped indinavir/lopinavir/ritonavir therapy (group1: 16.7%) than indinavir/ritonavir + NRTI treatment (group3: 45.5%) due to adverse events. Virological failure was the main reason for early termination of treatment with indinavir/lopinavir/ ritonavir before week 48 (group1: 50%). CONCLUSIONS: indinavir/lopinavir/ritonavir 800/400/ 100mg twice daily represents a therapy option with an adequate safety but only short term efficacy for extensively pretreated patients.

Prognostic importance of initial response in HIV-1 infected patients starting potent antiretroviral therapy: analysis of prospective studies.

BACKGROUND: We examined whether the initial virological and immunological response to highly active antiretroviral treatment (HAART) is prognostic in patients with HIV-1 who start HAART. METHODS: We analysed 13 cohort studies from Europe and North America including 9323 adult treatment-naive patients who were starting HAART with a combination of at least three drugs. We modelled clinical progression from month 6 after starting HAART, taking into account CD4 count and HIV-1 RNA measured at baseline and 6 months. FINDINGS: During 13408 years of follow-up 152 patients died and 874 developed AIDS or died. Compared with patients who had a 6-month CD4 count of fewer than 25 cells/microL, adjusted hazard ratios for AIDS or death were 0.55 (95%CI 0.32-0.96) for 25-49 cells/microL, 0.62 (0.40-0.96) for 50-99 cells/microL, 0.42 (0.28-0.64) for 100-199 cells/microL, 0.25 (0.16-0.38) for 200-349 cells/microL, and 0.18 (0.11-0.29) for 350 or more cells/microL at 6 months. Compared with patients who had a 6-month HIV-1 RNA of 100000 copies/mL or greater, adjusted hazard ratios for AIDS or death were 0.59 (0.41-0.86) for 10000-99999 copies/mL, 0.42 (0.29-0.61) for 500-9999 copies/mL, and 0.29 (0.21-0.39) for 6-month HIV-1 RNA of 500 copies/mL or fewer. Baseline CD4 and HIV-1 RNA were not associated with progression after controlling for 6-month concentrations. The probability of progression at 3 years ranged from 2.4% in the patients in the lowest-risk stratum to 83% in patients in the highest-risk stratum. INTERPRETATION: At 6 months after starting HAART, the current CD4 cell count and viral load, but not values at baseline, are strongly associated with subsequent disease progression. Our findings should inform guidelines on when to modify HAART.

Inhibitory effect of azidothymidine, 2'-3'-dideoxyadenosine, and 2'-3'-dideoxycytidine on in vitro growth of hematopoietic progenitor cells from normal persons and from patients with AIDS.

Therapy of patients with the acquired immunodeficiency syndrome (AIDS) or AIDS-related complex (ARC) with azidothymidine (AZT) and 2'-3'-dideoxycytidine (ddC) is complicated by severe anemia, neutropenia, and thrombocytopenia, the cause of which is unknown. We therefore tested the effect of AZT, ddC, and an additional 2'-3'-dideoxynucleoside analogue, 2'-3'-dideoxyadenosine (ddA), on the hematopoietic progenitor cells derived from the bone marrow of normal persons and patients with AIDS/ARC. All three substances dose-dependently inhibited the in vitro colony formation of the pluripotent (CFU-GEMM), as well as the erythroid (BFU-E) and granulocyte-macrophage progenitor cells (CFU-GM). The 50% inhibition of normal progenitors by AZT occurred at 0.13 microM for CFU-GEMM, 0.32 microM for BFU-E, and 1.9 microM for CFU-GM, by ddA at 15 microM for CFU-GEMM, 40 microM for BFU-E, and 140 microM for CFU-GM. ddC was the most toxic agent and already inhibited 71% +/- 16% (mean +/- standard error of the mean [SEM]) of CFU-GEMM and 52% +/- 22% of BFU-E at 0.1 microM, whereas the 50% inhibition of CFU-GM was reached at 0.3 microM. Hematotoxicity occurred at concentrations lower than necessary to inhibit the human immunodeficiency virus (HIV), except for ddA, which is 100 times less toxic than AZT whereas its antiviral effect is only 10 times less. The inhibition of progenitor cells from AIDS patients by the 2'-3'-dideoxynucleosides was comparable to normal progenitors, except for a higher sensitivity of AIDS-derived CFU-GEMM and BFU-E to AZT.

HIV-1 RNA, CD4 cell count and the risk of progression to AIDS and death during treatment with HIV-1 reverse transcriptase inhibitors.

CONTEXT: There is little information available on the correlation between HIV-1 RNA level, CD4 cell count and the risk of progression to AIDS or death during treatment with reverse transcriptase inhibitors. OBJECTIVES: To define the correlation between HIV-1 RNA level, CD4 cell count and the 1 year risk of progression to AIDS or death. DESIGN: Pooled analysis of six randomized clinical trials of zidovudine/lamivudine versus control treatments. SETTING: Investigational sites in Europe, North America, Australia and South Africa. PATIENTS: The trials recruited 1488 adult HIV-1-infected male and female patients aged > or = 18 years, with inclusion CD4 cell count between 25 and 500 x 10(6) cells/l. Patients were either nucleoside analogue-naive or pre-treated, and at all stages of HIV-1 disease. MAIN OUTCOME MEASURES: : Progression (defined as all new and recurrent AIDS-defining events or death) was correlated with the HIV-1 RNA level and CD4 cell count during the first 8 to 52 weeks of treatment. RESULTS: During a median 1 year follow up, progression was largely restricted to patients with both low CD4 cell count (< or = 200 x 10(6) cells/l) and high HIV-1 RNA level (> 5000 copies/ml). There was an increase in the incidence of progression events with rises in HIV-1 RNA level > 5000 copies/ml and reductions in CD4 cell count under 200 x 10(6) cells/l. The events occurring with HIV-1 RNA < 5000 copies/ml were generally atypical. CONCLUSIONS: Progression to AIDS or death is rare for patients with HIV-1 RNA < or = 5000 copies/ml, particularly when CD4 cell count is more than 200 x 10(6) cells/l.

The virological response to highly active antiretroviral therapy over the first 24 weeks of therapy according to the pre-therapy viral load and the weeks 4-8 viral load.

OBJECTIVES: To describe the viral response to HAART by weeks 4 and 8 in previously antiretroviral-naive patients. To assess whether the weeks 4 or 8 viral loads are useful predictors of viral suppression by week 24. DESIGN: A large clinical database including 453 antiretroviral-naive patients whose plasma viral load was monitored every 4 weeks. METHODS: Observed probabilities of achieving a viral load < or = 500 copies/ml by week 24 (days 84-168) from starting highly active antiretroviral therapy (HAART) were calculated according to viral loads at weeks 4 and 8. RESULTS: A total of 42.4% of patients (153/361) reached < or = 500 copies/ml viral load by week 4 and 70.4% (245/348) by week 8. Viral suppression below 500 copies/ml by 4-8 weeks was similar irrespective of the pre-HAART viral load. In patients with viral loads above 10000 copies/ml at week 4, 60.6% (20/33) achieved < or = 500 copies/ml by week 24. In patients with viral loads still above 10000 copies/ml at week 8, only 42.3% (11/26) achieved < or = 500 copies/ml by week 24, and only 33.3% (3/9) maintained viral suppression below 500 copies/ml to week 48. CONCLUSION: Viral loads at weeks 4 and 8 should be monitored to detect early signs of low subsequent viral suppression. For previously antiretroviral-naive patients whose viral loads after 8 weeks of HAART are still above 10000, there is an urgent need to assess adherence to therapy, drug levels and resistance, so management can be modified accordingly to reduce the rate of week 24 virological failure.

Changing incidence of AIDS-defining illnesses in the era of antiretroviral combination therapy.

OBJECTIVE: To determine the incidence of AIDS-defining opportunistic infections and malignancies over a 5-year period from 1992 to 1996. STUDY POPULATION: Subcohort of 1003 homosexual men with HIV infection and CD4 count less than 200 x 10(6) cells/l from the Frankfurt AIDS Cohort Study. METHODS: Data including the earliest date that a CD4 T-lymphocyte count < 200 x 10(6)/l was reached and the dates of AIDS-defining events were compiled from medical records. Incidence analyses for AIDS-defining events and death during the subsequent 5 years (1992-1996) were performed using rates per 100 person-years of exposure. RESULTS: During the observation period, the number of patients per year with CD4 T-lymphocyte counts < 200 x 10(6)/l varied between 402 and 511. In 1992, 56.7% of patients experienced at least one AIDS-defining illness, and 20.7% in 1996. The annual number of AIDS-defining events per 100 patient-years of observation declined from 143.5 in 1992 to 38.3 in 1996, and the number of AIDS-related deaths fell from 25.7 to 12.9. Analysis of the number of events confirmed this trend for malignancies and single opportunistic infections, with the exception of mycobacterial diseases. CONCLUSIONS: The incidence of AIDS-defining events in patients with advanced HIV infection at Frankfurt University Hospital has declined by more than 70% from 1992 to 1996.

Durability of HIV-1 viral suppression over 3.3 years with multi-drug antiretroviral therapy in previously drug-naive individuals.

BACKGROUND: Relatively little is known about the long-term durability of viral suppression in individuals initially achieving a viral load of less than 50 copies/ml within 24 weeks of starting antiretroviral therapy, nor the extent to which therapy interruption accounts for the loss of suppression. METHODS: We intensely followed all 336 antiretroviral-naive patients attending the Goethe Universitat Clinic who began multi-drug combination regimens and in whom a viral load of less than 50 copies/ml was achieved within 24 weeks, in order to assess the risk of viral load rebound. Inspection of case notes allowed the distinction of viral rebound according to whether there was an associated complete interruption of therapy. RESULTS: A total of 61 patients experienced viral rebound during 543.1 person-years of follow-up, giving a 25.3% risk of rebound by 3.3 years from first achieving viral suppression. However, for 47 of the patients with viral rebound there was an associated documented complete interruption of antiretroviral therapy, mostly as a result of co-morbidities, leaving 14 who appear to represent a failure of the virological efficacy of therapy (viral breakthrough; 5.2% risk by 3.3 years). The risk of viral breakthrough declined with the increased duration of suppression (P = 0.01). CONCLUSION: The intrinsic virological effectiveness of multi-drug antiretroviral therapy in previously drug-naive individuals appears to be such that viral suppression, once achieved, can be maintained for several years in patients not interrupting therapy. The major challenge is to develop regimens that can be taken consistently and safely for such long periods of time.

The impact of protease inhibitor-containing highly active antiretroviral therapy on progression of HIV disease and its relationship to CD4 and viral load.

OBJECTIVE: To compare the rate of disease progression according to viral load and CD4 cell count in patients receiving or not receiving highly active antiretroviral therapy (HAART), defined as protease inhibitor-containing regimens. DESIGN: An observational study, with prospectively collected data. METHODS: All patients attending the HIV Outpatient clinic as of 1 January 1995 (n = 2083) were included. Follow-up was until the first AIDS-defining event or death. Associations between viral load or CD4 cell count and disease progression were assessed using a person-years approach. Event rates were compared using Poisson regression analysis; a multivariate model was used to assess the independent effects of CD4, viral load and treatment group on event rates and to consider interactions between these variables. RESULTS: The event rates increased with lower CD4 cell count and higher viral load for both treatment groups and were generally lower in the HAART group. In a multivariate analysis, lower CD4 cell counts and higher viral loads remained significantly associated with disease progression, irrespective of treatment group. However, the event rate was significantly lower for the HAART group compared with the control group (relative rate 0.53, P < 0.001). CONCLUSIONS: HAART-treated patients with high viral loads and CD4 cell counts experienced reduced disease progression compared with individuals with the same CD4 cell count and viral load not receiving HAART. Consequently, the short-term prognosis associated with viral load levels and CD4 cell counts may differ in patients on HAART. Whether this effect will be observed with non-protease-inhibitor-containing HAART is not known at this time.

Simplification with abacavir-based triple nucleoside therapy versus continued protease inhibitor-based highly active antiretroviral therapy in HIV-1-infected patients with undetectable plasma HIV-1 RNA.

OBJECTIVE: To assess the antiviral efficacy, safety and adherence in patients switched to an abacavir-containing nucleoside reverse transcriptase inhibitor (NRTI) regimen after long-term HIV-1 RNA suppression with a dual NRTI/protease inhibitor (PI) combination. METHODS: In an open-label, multicentre study, patients receiving 2NRTI plus PI for at least 6 months, with a history of undetectable plasma HIV-1 RNA since the initiation of therapy and plasma HIV-1 RNA < 50 copies/ml at screening, were randomly assigned to replace the PI with abacavir (n = 105) or continue the same treatment (n = 106). Clinical assessments included plasma HIV-1 RNA, chemistry, haematology, lymphocyte counts, and adverse event reports. Adherence to treatment was assessed by patient self-report. RESULTS: A significantly longer time to treatment failure was demonstrated in the abacavir arm compared with the PI arm (P = 0.03) while treatment failure was experienced by significantly more patients in the PI arm: 24 (23%) versus 12 (12%) (P = 0.03). Therapy-limiting toxicity led to treatment failure in eight versus 14 cases in the abacavir and PI arms, respectively, whereas virological rebound was the cause in four versus two cases. Significant reductions in cholesterol and non-fasting triglyceride plasma levels at 48 weeks were observed in the abacavir arm (P < 0.001 andP = 0.035, respectively). The number of patients reporting no difficulty in taking their therapy showed a marked increase from baseline in the abacavir arm. CONCLUSION: The replacement of PI by abacavir in a triple combination regimen following prolonged suppression of plasma HIV-1 RNA provides continued virological suppression, significant improvements in lipid abnormalities and enhanced ease of dosing.

Reductions in HIV-1 disease progression for zidovudine/lamivudine relative to control treatments: a meta-analysis of controlled trials.

OBJECTIVES: Four randomized double-blind trials have demonstrated that zidovudine/lamivudine (ZDV/3TC) reduces HIV RNA and raises CD4 counts relative to control treatments (ZDV or ZDV/zalcitabine (ddC)]. A meta-analysis of the clinical events in these trails was conducted to determine whether treatment with ZDV/3TC was also associated with a clinical benefit. DESIGN: The four trials, ZDV/3TC versus ZDV (NUCA3001, NUCB3001, NUCB3002) or versus ZDV/ddC (NUCA3002), were run concurrently, using the same doses of ZDV and 3TC. SETTING: Investigational sites in Europe and North America. PATIENTS: The trials recruited 972 HIV-1-positive, male and female patients aged > or = 18 years, with CD4 counts of 100-500 cells x 10(6)I. Two trials were for ZDV-naive patients and two were for ZDV pre-treated patients. MAIN OUTCOME MEASURES: Progression to first new Centers for Disease Control and Prevention (CDC) B or C event was compared between all ZDV/3TC arms and all control (ZDV, ZDV/ddC) arms. RESULTS: A total of 118 patients progressed to a first new CDC B/C event during the four trials, while 28 progressed to a new CDC event. Meta-analysis of the trials showed a 49% reduction in progression to new CDC B/C events (relative risk, 0.509; 95% confidence interval, 0.365-0.710; P < 0.0001) and a 66% reduction in progression to new CDC C events (relative risk, 0.344; 95% confidence interval, 0.169-0.700; P = 0.003) for the ZDV/3TC patients relative to the control patients. Reductions in progression to CDC B/C disease were seen in subgroups of naive and pre-treated patients, those with high and low CD4 counts and symptomatic and asymptomatic patients. CONCLUSIONS: ZDV/3TC combination treatment delays the progression of CDC B/C disease compared with control treatments. In view of the low incidence of CDC C events, the results for progression to CDC C disease should be interpreted with caution.