Jürgen K. Rockstroh

Raltegravir with optimized background therapy for resistant HIV-1 infection.

BACKGROUND Raltegravir (MK-0518) is an inhibitor of human immunodeficiency virus type 1 (HIV-1) integrase active against HIV-1 susceptible or resistant to older antiretroviral drugs. METHODS We conducted two identical trials in different geographic regions to evaluate the safety and efficacy of raltegravir, as compared with placebo, in combination with optimized background therapy, in patients infected with HIV-1 that has triple-class drug resistance in whom antiretroviral therapy had failed. Patients were randomly assigned to raltegravir or placebo in a 2:1 ratio. RESULTS In the combined studies, 699 of 703 randomized patients (462 and 237 in the raltegravir and placebo groups, respectively) received the study drug. Seventeen of the 699 patients (2.4%) discontinued the study before week 16. Discontinuation was related to the study treatment in 13 of these 17 patients: 7 of the 462 raltegravir recipients (1.5%) and 6 of the 237 placebo recipients (2.5%). The results of the two studies were consistent. At week 16, counting noncompletion as treatment failure, 355 of 458 raltegravir recipients (77.5%) had HIV-1 RNA levels below 400 copies per milliliter, as compared with 99 of 236 placebo recipients (41.9%, P<0.001). Suppression of HIV-1 RNA to a level below 50 copies per milliliter was achieved at week 16 in 61.8% of the raltegravir recipients, as compared with 34.7% of placebo recipients, and at week 48 in 62.1% as compared with 32.9% (P<0.001 for both comparisons). Without adjustment for the length of follow-up, cancers were detected in 3.5% of raltegravir recipients and in 1.7% of placebo recipients. The overall frequencies of drug-related adverse events were similar in the raltegravir and placebo groups. CONCLUSIONS In HIV-infected patients with limited treatment options, raltegravir plus optimized background therapy provided better viral suppression than optimized background therapy alone for at least 48 weeks. (ClinicalTrials.gov numbers, NCT00293267 and NCT00293254.)

Effect of antiretroviral therapy on liver-related mortality in patients with HIV and hepatitis C virus coinfection

BACKGROUND Highly active antiretroviral therapy (HAART) has improved the prognosis of HIV infection. However, replication of hepatitis C virus (HCV) is not inhibited by HAART, and treatment-related hepatotoxicity is common. To clarify the effect of HAART in HIV/HCV-coinfected patients, we studied liver-related mortality and overall mortality in 285 patients who were regularly treated during the period 1990-2002 at our department. METHODS Survival was analysed retrospectively by Kaplan-Meier and Coxs regression analyses after patients (81% haemophiliacs) had been stratified into three groups according to their antiretroviral therapy (HAART n=93, available after 1995; treatment exclusively with nucleoside analogues n=55, available after 1992; or no treatment, n=137). FINDINGS Liver-related mortality rates were 0.45, 0.69, and 1.70 per 100 person-years in the HAART, antiretroviral-treatment, and untreated groups. Kaplan-Meier analysis of liver-related mortality confirmed the significant survival benefit in patients with antiretroviral therapy (p=0.018), and regression analysis identified HAART (odds ratio 0.106 [95% CI 0.020-0.564]), antiretroviral treatment (0.283 [0.103-0.780]), CD4-positive T-cell count (0.746 [0.641-0.868] per 0.05x10(9) cells/L), serum cholinesterase (0.962 [0.938-0.986] per 100 U/L), and age (1.065 [1.027-1.105] per year) as independent predictors of liver-related survival. Severe drug-related hepatotoxicity was seen in five patients treated with nucleoside analogues alone and 13 treated with HAART. No patient died from drug-related hepatotoxicity. INTERPRETATION In addition to improved overall survival, antiretroviral therapy significantly reduced long-term liver-related mortality in our patients. This survival benefit seems to outweigh by far the associated risks of severe hepatotoxicity.

Subgroup and Resistance Analyses of Raltegravir for Resistant HIV-1 Infection

BACKGROUND We evaluated the efficacy of raltegravir and the development of viral resistance in two identical trials involving patients who were infected with human immunodeficiency virus type 1 (HIV-1) with triple-class drug resistance and in whom antiretroviral therapy had failed. METHODS We conducted subgroup analyses of the data from week 48 in both studies according to baseline prognostic factors. Genotyping of the integrase gene was performed in raltegravir recipients who had virologic failure. RESULTS Virologic responses to raltegravir were consistently superior to responses to placebo, regardless of the baseline values of HIV-1 RNA level; CD4 cell count; genotypic or phenotypic sensitivity score; use or nonuse of darunavir, enfuvirtide, or both in optimized background therapy; or demographic characteristics. Among patients in the two studies combined who were using both enfuvirtide and darunavir for the first time, HIV-1 RNA levels of less than 50 copies per milliliter were achieved in 89% of raltegravir recipients and 68% of placebo recipients. HIV-1 RNA levels of less than 50 copies per milliliter were achieved in 69% and 80% of the raltegravir recipients and in 47% and 57% of the placebo recipients using either darunavir or enfuvirtide for the first time, respectively. At 48 weeks, 105 of the 462 raltegravir recipients (23%) had virologic failure. Genotyping was performed in 94 raltegravir recipients with virologic failure. Integrase mutations known to be associated with phenotypic resistance to raltegravir arose during treatment in 64 patients (68%). Forty-eight of these 64 patients (75%) had two or more resistance-associated mutations. CONCLUSIONS When combined with an optimized background regimen in both studies, a consistently favorable treatment effect of raltegravir over placebo was shown in clinically relevant subgroups of patients, including those with baseline characteristics that typically predict a poor response to antiretroviral therapy: a high HIV-1 RNA level, low CD4 cell count, and low genotypic or phenotypic sensitivity score. (ClinicalTrials.gov numbers, NCT00293267 and NCT00293254.)

Efficacy of short-term monotherapy with maraviroc, a new CCR5 antagonist, in patients infected with HIV-1

We assessed the efficacy and safety of 10-d monotherapy with the orally administered CCR5 antagonist maraviroc in 63 HIV-1-positive individuals prescreened for the absence of CXCR4-using virus. Maximum reduction in viral load occurred at a median of 10–15 d, with a mean reduction of ≥1.6 log10 copies/ml at all twice daily doses ≥100 mg. These results provide proof of concept that CCR5 antagonism is a viable antiretroviral therapeutic approach.

Selective escape from CD8+ T-Cell responses represents a major driving force of Human Immunodeficiency Virus Type 1 (HIV-1) sequence diversity and reveals constraints on HIV-1 evolution

ABSTRACT The sequence diversity of human immunodeficiency virus type 1 (HIV-1) represents a major obstacle to the development of an effective vaccine, yet the forces impacting the evolution of this pathogen remain unclear. To address this issue we assessed the relationship between genome-wide viral evolution and adaptive CD8+ T-cell responses in four clade B virus-infected patients studied longitudinally for as long as 5 years after acute infection. Of the 98 amino acid mutations identified in nonenvelope antigens, 53% were associated with detectable CD8+ T-cell responses, indicative of positive selective immune pressures. An additional 18% of amino acid mutations represented substitutions toward common clade B consensus sequence residues, nine of which were strongly associated with HLA class I alleles not expressed by the subjects and thus indicative of reversions of transmitted CD8 escape mutations. Thus, nearly two-thirds of all mutations were attributable to CD8+ T-cell selective pressures. A closer examination of CD8 escape mutations in additional persons with chronic disease indicated that not only did immune pressures frequently result in selection of identical amino acid substitutions in mutating epitopes, but mutating residues also correlated with highly polymorphic sites in both clade B and C viruses. These data indicate a dominant role for cellular immune selective pressures in driving both individual and global HIV-1 evolution. The stereotypic nature of acquired mutations provides support for biochemical constraints limiting HIV-1 evolution and for the impact of CD8 escape mutations on viral fitness.

The way forward in HCV treatment--finding the right path.

Infection with the hepatitis C virus (HCV) represents an important health-care problem worldwide. The prevalence of HCV-related disease is increasing, and no vaccine is yet available. Since the identification of HCV as the causative agent of non-A, non-B hepatitis, treatment has progressed rapidly, but morbidity and mortality rates are still predicted to rise. Novel, more efficacious and tolerable therapies are urgently needed, and a greater understanding of the viral life cycle has led to an increase in the number of possible targets for antiviral intervention. Here we review the specific challenges posed by HCV, and recent developments in the design of vaccines and novel antiviral agents.

Reply: Virological treatment failure of protease inhibitor therapy in an unselected cohort of HIV-infected patients.

Objective: To determine the rate of virological treatment failure with protease inhibitor therapy in unselected patients and to assess underlying risk factors. Design and setting: Retrospective study in two German tertiary care treatment centres. Patients: A total of 198 HIV-infected patients treated with protease inhibitors in 1996. Main outcome measures: Levels of HIV RNA 1-6 months after start of treatment; definition of treatment failure of < 1 log 10 reduction in plasma HIV RNA within 6 months after starting protease inhibitor therapy; multivariate analysis of risk factors for treatment failures. Results: A total of 226 treatment episodes with protease inhibitors were evaluable (saquinavir, 83; ritonavir, 47; indinavir, 96). The rate of virological treatment failure was 44% (saquinavir, 64%; ritonavir, 38%; indinavir, 30%). In a multivariate analysis, the following independent risk factors for virological failure were found: CD4 cell count, pretreatment with antiretroviral drugs (number), and protease inhibitor (compound). The relative risk reduction for each CD4 cell count increase was 0.997 (P = 0.012), 2.64 for pretreatment with one or two drugs versus no drug (P = 0.05), 2.97 for pretreatment with more than two drugs versus no drug (P = 0.05), and 4.62 for treatment with saquinavir versus indinavir (P = 0.001). Conclusion: An unexpectedly high rate of virological treatment failure of protease inhibitor therapy was found in an unselected cohort of HIV-infected patients. Response to antiretroviral combination therapy in normal clinical practice may considerably differ from results of randomized clinical trials. Further studies are warranted to find optimal treatment strategies for both initial and salvage therapy.

Co-formulated elvitegravir, cobicistat, emtricitabine, and tenofovir disoproxil fumarate versus ritonavir-boosted atazanavir plus co-formulated emtricitabine and tenofovir disoproxil fumarate for initial treatment of HIV-1 infection: a randomised, double-blind, phase 3, non-inferiority trial.

BACKGROUND The HIV integrase strand transfer inhibitor elvitegravir (EVG) has been co-formulated with the CYP3A4 inhibitor cobicistat (COBI), emtricitabine (FTC), and tenofovir disoproxil fumarate (TDF) into a once-daily, single tablet. We compared EVG/COBI/FTC/TDF with a ritonavir-boosted (RTV) protease inhibitor regimen of atazanavir (ATV)/RTV+FTC/TDF as initial therapy for HIV-1 infection. METHODS This phase 3, non-inferiority study enrolled treatment-naive patients with an HIV-1 RNA concentration of 5000 copies per mL or more and susceptibility to atazanavir, emtricitabine, and tenofovir. Patients were randomly assigned (1:1) to receive EVG/COBI/FTC/TDF or ATV/RTV+FTC/TDF plus matching placebos, administered once daily. Randomisation was by a computer-generated random sequence, accessed via an interactive telephone and web response system. Patients, and investigators and study staff who gave treatments, assessed outcomes, or analysed data were masked to the assignment. The primary endpoint was HIV RNA concentration of 50 copies per mL or less after 48 weeks (according to the US FDA snapshot algorithm), with a 12% non-inferiority margin. This trial is registered with ClinicalTrials.gov, number NCT01106586. FINDINGS 1017 patients were screened, 715 were enrolled, and 708 were treated (353 with EVG/COBI/FTC/TDF and 355 with ATV/RTV+FTC/TDF). EVG/COBI/FTC/TDF was non-inferior to ATV/RTV+FTC/TDF for the primary outcome (316 patients [89·5%] vs 308 patients [86·8%], adjusted difference 3·0%, 95% CI -1·9% to 7·8%). Both regimens had favourable safety and tolerability; 13 (3·7%) versus 18 (5·1%) patients discontinued treatment because of adverse events. Fewer patients receiving EVG/COBI/FTC/TDF had abnormal results in liver function tests than did those receiving ATV/RTV+FTC/TDF and had smaller median increases in fasting triglyceride concentration (90 μmol/L vs 260 μmol/L, p=0·006). Small median increases in serum creatinine concentration with accompanying decreases in estimated glomerular filtration rate occurred in both study groups by week 2; they generally stabilised by week 8 and did not change up to week 48 (median change 11 μmol/L vs 7 μmol/L). INTERPRETATION If regulatory approval is given, EVG/COBI/FTC/TDF would be the first integrase-inhibitor-based regimen given once daily and the only one formulated as a single tablet for initial HIV treatment. FUNDING Gilead Sciences.

Care of patients with hepatitis C and HIV co-infection.

Liver disease caused by chronic hepatitis C virus (HCV) infection is now a leading cause of morbidity and mortality among HIV-infected patients in the developed world, where classic opportunistic complications of severe immunodeficiency have declined dramatically as a result of the widespread use of potent antiretroviral therapies [1]. Over the past few years, several consensus reports have addressed the issue of viral hepatitis and HIV infection [2,3]. In 2000, a group of experts in the field were invited to join the HCV– HIV International Panel. The first consensus conference took place in Paris [4]. Two years later, the large amount of new information on HCV and HIV, as well as important changes made in the guidelines for using antiretroviral drugs [5], prompted us to organize another consensus conference, which was held in Barcelona in the summer of 2002. Following international recommendations for the development of clinical guidelines [6], the meeting was planned as a full oneday workshop in which nine experts in the field of HIV and viral hepatitis discussed a total of nine questions, which were selected in advance as the most relevant and currently conflicting topics in the management of chronic viral hepatitis in the setting of HIV infection. A draft was written and circulated among panel members during the following months. Finally, in a second meeting that took place in February 2003, a final consensus was reached, and is presented here. The statements are graded according to the Infectious Diseases Society of America scoring system [6], with minor changes (see Table 1).

Once daily dolutegravir (S/GSK1349572) in combination therapy in antiretroviral-naive adults with HIV: planned interim 48 week results from SPRING-1, a dose-ranging, randomised, phase 2b trial

BACKGROUND Dolutegravir (S/GSK1349572) is a new HIV-1 integrase inhibitor that has antiviral activity with once daily, unboosted dosing. SPRING-1 is an ongoing study designed to select a dose for phase 3 assessment. We present data from preplanned primary and interim analyses. METHODS In a phase 2b, multicentre, dose-ranging study, treatment-naive adults were randomly assigned (1:1:1:1) to receive 10 mg, 25 mg, or 50 mg dolutegravir or 600 mg efavirenz. Dose but not drug allocation was masked. Randomisation was by a central integrated voice-response system according to a computer-generated code. Study drugs were given with either tenofovir plus emtricitabine or abacavir plus lamivudine. Our study was done at 34 sites in France, Germany, Italy, Russia, Spain, and the USA beginning on July 9, 2009. Eligible participants were seropositive for HIV-1, aged 18 years or older, and had plasma HIV RNA viral loads of at least 1000 copies per mL and CD4 counts of at least 200 cells per μL. Our primary endpoint was the proportion of participants with viral load of less than 50 copies per mL at week 16 and we present data to week 48. Analyses were done on the basis of allocation group and included all participants who received at least one dose of study drug. This study is registered with ClinicalTrials.gov, number NCT00951015. FINDINGS 205 patients were randomly allocated and received at least one dose of study drug: 53, 51, and 51 to receive 10 mg, 25 mg, and 50 mg dolutegravir, respectively, and 50 to receive efavirenz. Week 16 response rates to viral loads of at most 50 copies per mL were 93% (144 of 155 participants) for all doses of dolutegravir (with little difference between dose groups) and 60% (30 of 50) for efavirenz; week 48 response rates were 87% (139 of 155) for all doses of dolutegravir and 82% (41 of 50) for efavirenz. Response rates between nucleoside reverse transcriptase inhibitor subgroups were similar. We identified three virological failures in the dolutegravir groups and one in the efavirenz group-we did not identify any integrase inhibitor mutations. We did not identify any dose-related clinical or laboratory toxic effects, with more drug-related adverse events of moderate-or-higher intensity in the efavirenz group (20%) than the dolutegravir group (8%). We did not judge that any serious adverse events were related to dolutegravir. INTERPRETATION Dolutegravir was effective when given once daily without a pharmacokinetic booster and was well tolerated at all assessed doses. Our findings support the assessment of once daily 50 mg dolutegravir in phase 3 trials.