Gerd Fätkenheuer

Initiation of Antiretroviral Therapy in Early Asymptomatic HIV Infection

BACKGROUND Data from randomized trials are lacking on the benefits and risks of initiating antiretroviral therapy in patients with asymptomatic human immunodeficiency virus (HIV) infection who have a CD4+ count of more than 350 cells per cubic millimeter. METHODS We randomly assigned HIV-positive adults who had a CD4+ count of more than 500 cells per cubic millimeter to start antiretroviral therapy immediately (immediate-initiation group) or to defer it until the CD4+ count decreased to 350 cells per cubic millimeter or until the development of the acquired immunodeficiency syndrome (AIDS) or another condition that dictated the use of antiretroviral therapy (deferred-initiation group). The primary composite end point was any serious AIDS-related event, serious non-AIDS-related event, or death from any cause. RESULTS A total of 4685 patients were followed for a mean of 3.0 years. At study entry, the median HIV viral load was 12,759 copies per milliliter, and the median CD4+ count was 651 cells per cubic millimeter. On May 15, 2015, on the basis of an interim analysis, the data and safety monitoring board determined that the study question had been answered and recommended that patients in the deferred-initiation group be offered antiretroviral therapy. The primary end point occurred in 42 patients in the immediate-initiation group (1.8%; 0.60 events per 100 person-years), as compared with 96 patients in the deferred-initiation group (4.1%; 1.38 events per 100 person-years), for a hazard ratio of 0.43 (95% confidence interval [CI], 0.30 to 0.62; P<0.001). Hazard ratios for serious AIDS-related and serious non-AIDS-related events were 0.28 (95% CI, 0.15 to 0.50; P<0.001) and 0.61 (95% CI, 0.38 to 0.97; P=0.04), respectively. More than two thirds of the primary end points (68%) occurred in patients with a CD4+ count of more than 500 cells per cubic millimeter. The risks of a grade 4 event were similar in the two groups, as were the risks of unscheduled hospital admissions. CONCLUSIONS The initiation of antiretroviral therapy in HIV-positive adults with a CD4+ count of more than 500 cells per cubic millimeter provided net benefits over starting such therapy in patients after the CD4+ count had declined to 350 cells per cubic millimeter. (Funded by the National Institute of Allergy and Infectious Diseases and others; START ClinicalTrials.gov number, NCT00867048.).

Timing of initiation of antiretroviral therapy in AIDS-free HIV-1-infected patients: a collaborative analysis of 18 HIV cohort studies

Summary Background The CD4 cell count at which combination antiretroviral therapy should be started is a central, unresolved issue in the care of HIV-1-infected patients. In the absence of randomised trials, we examined this question in prospective cohort studies. Methods We analysed data from 18 cohort studies of patients with HIV. Antiretroviral-naive patients from 15 of these studies were eligible for inclusion if they had started combination antiretroviral therapy (while AIDS-free, with a CD4 cell count less than 550 cells per μL, and with no history of injecting drug use) on or after Jan 1, 1998. We used data from patients followed up in seven of the cohorts in the era before the introduction of combination therapy (1989–95) to estimate distributions of lead times (from the first CD4 cell count measurement in an upper range to the upper threshold of a lower range) and unseen AIDS and death events (occurring before the upper threshold of a lower CD4 cell count range is reached) in the absence of treatment. These estimations were used to impute completed datasets in which lead times and unseen AIDS and death events were added to data for treated patients in deferred therapy groups. We compared the effect of deferred initiation of combination therapy with immediate initiation on rates of AIDS and death, and on death alone, in adjacent CD4 cell count ranges of width 100 cells per μL. Findings Data were obtained for 21 247 patients who were followed up during the era before the introduction of combination therapy and 24 444 patients who were followed up from the start of treatment. Deferring combination therapy until a CD4 cell count of 251–350 cells per μL was associated with higher rates of AIDS and death than starting therapy in the range 351–450 cells per μL (hazard ratio [HR] 1·28, 95% CI 1·04–1·57). The adverse effect of deferring treatment increased with decreasing CD4 cell count threshold. Deferred initiation of combination therapy was also associated with higher mortality rates, although effects on mortality were less marked than effects on AIDS and death (HR 1·13, 0·80–1·60, for deferred initiation of treatment at CD4 cell count 251–350 cells per μL compared with initiation at 351–450 cells per μL). Interpretation Our results suggest that 350 cells per μL should be the minimum threshold for initiation of antiretroviral therapy, and should help to guide physicians and patients in deciding when to start treatment. Funding UK Medical Research Council.

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.

Subgroup analyses of maraviroc in previously treated R5 HIV-1 infection.

BACKGROUND We conducted subanalyses of the combined results of the Maraviroc versus Optimized Therapy in Viremic Antiretroviral Treatment-Experienced Patients (MOTIVATE) 1 and MOTIVATE 2 studies to better characterize the efficacy and safety of maraviroc in key subgroups of patients. METHODS We analyzed pooled data from week 48 from the two studies according to sex, race or ethnic group, clade, CC chemokine receptor 5 (CCR5) delta32 genotype, viral load at the time of screening, the use or nonuse of enfuvirtide in optimized background therapy (OBT), the baseline CD4 cell count, the number of active antiretroviral drugs coadministered, the first use of selected background agents, and tropism at baseline. Changes in viral tropism and the CD4 count at treatment failure were evaluated. Data on aminotransferase levels in patients coinfected with hepatitis B virus (HBV) or hepatitis C virus (HCV) were also analyzed. RESULTS A treatment benefit of maraviroc plus OBT over placebo plus OBT was shown in all subgroups, including patients with a low CD4 cell count at baseline, those with a high viral load at screening, and those who had not received active agents in OBT. Analyses of the virologic response according to the first use of selected background drugs showed the additional benefit of adding a potent new drug to maraviroc at the initiation of maraviroc therapy. More patients in whom maraviroc failed had a virus binding to the CXC chemokine receptor 4 (CXCR4) at failure, but there was no evidence of a decrease in the CD4 cell count at failure in such patients as compared with those in whom placebo failed. Subanalyses involving patients coinfected with HBV or HCV revealed no evidence of excess hepatotoxic effects as compared with baseline. CONCLUSIONS Subanalyses of pooled data from week 48 indicate that maraviroc provides a valuable treatment option for a wide spectrum of patients with R5 HIV-1 infection who have been treated previously. (ClinicalTrials.gov numbers, NCT00098306 and NCT00098722.)

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.

Switch to a raltegravir-based regimen versus continuation of a lopinavir-ritonavir-based regimen in stable HIV-infected patients with suppressed viraemia (SWITCHMRK 1 and 2): two multicentre, double-blind, randomised controlled trials

BACKGROUND To reduce lipid abnormalities and other side-effects associated with antiretroviral regimens containing lopinavir-ritonavir, patients might want to switch one or more components of their regimen. We compared substitution of raltegravir for lopinavir-ritonavir with continuation of lopinavir-ritonavir in HIV-infected patients with stable viral suppression on lopinavir-ritonavir-based combination therapy. METHODS The SWITCHMRK 1 and 2 studies were multicentre, double-blind, double-dummy, phase 3, randomised controlled trials. HIV-infected patients aged 18 years or older were eligible if they had documented viral RNA (vRNA) concentration below the limit of assay quantification for at least 3 months while on a lopinavir-ritonavir-based regimen. 707 eligible patients were randomly allocated by interactive voice response system in a 1:1 ratio to switch from lopinavir-ritonavir to raltegravir (400 mg twice daily; n=353) or to remain on lopinavir-ritonavir (two 200 mg/50 mg tablets twice daily; n=354), while continuing background therapy consisting of at least two nucleoside or nucleotide reverse transcriptase inhibitors. Primary endpoints were the mean percentage change in serum lipid concentrations from baseline to week 12; the proportion of patients with vRNA concentration less than 50 copies per mL at week 24 (with all treated patients who did not complete the study counted as failures) with a prespecified non-inferiority margin of -12% for each study; and the frequency of adverse events up to 24 weeks. Analyses were done according to protocol. These trials are registered with ClinicalTrials.gov, numbers NCT00443703 and NCT00443729. FINDINGS 702 patients received at least one dose of study drug and were included in the efficacy and safety analyses for the combined trials (raltegravir, n=350; lopinavir-ritonavir, n=352). Percentage changes in lipid concentrations from baseline to week 12 were significantly greater (p<0.0001) in the raltegravir group than in the lopinavir-ritonavir group in each study, yielding combined results for total cholesterol -12.6%vs 1.0%, non-HDL cholesterol -15.0%vs 2.6%, and triglycerides -42.2%vs 6.2%. At week 24, 293 (84.4%, 95% CI 80.2-88.1) of 347 patients in the raltegravir group had vRNA concentration less than 50 copies per mL compared with 319 (90.6%, 87.1-93.5) of 352 patients in the lopinavir-ritonavir group (treatment difference -6.2%, -11.2 to -1.3). Clinical and laboratory adverse events occurred at similar frequencies in the treatment groups. There were no serious drug-related adverse events or deaths. The only drug-related clinical adverse event of moderate to severe intensity reported in 1% or more of either treatment group was diarrhoea, which occurred in ten patients in the lopinavir-ritonavir group (3%) and no patients in the raltegravir group. The studies were terminated at week 24 because of lower than expected virological efficacy in the raltegravir group compared with the lopinavir-ritonavir group. INTERPRETATION Although switching to raltegravir was associated with greater reductions in serum lipid concentrations than was continuation of lopinavir-ritonavir, efficacy results did not establish non-inferiority of raltegravir to lopinavir-ritonavir. FUNDING Merck.

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.

HIV treatment response and prognosis in Europe and North America in the first decade of highly active antiretroviral therapy: a collaborative analysis.

BACKGROUND Highly active antiretroviral therapy (HAART) for the treatment of HIV infection was introduced a decade ago. We aimed to examine trends in the characteristics of patients starting HAART in Europe and North America, and their treatment response and short-term prognosis. METHODS We analysed data from 22,217 treatment-naive HIV-1-infected adults who had started HAART and were followed up in one of 12 cohort studies. The probability of reaching 500 or less HIV-1 RNA copies per mL by 6 months, and the change in CD4 cell counts, were analysed for patients starting HAART in 1995-96, 1997, 1998, 1999, 2000, 2001, and 2002-03. The primary endpoints were the hazard ratios for AIDS and for death from all causes in the first year of HAART, which were estimated using Cox regression. RESULTS The proportion of heterosexually infected patients increased from 20% in 1995-96 to 47% in 2002-03, and the proportion of women from 16% to 32%. The median CD4 cell count when starting HAART increased from 170 cells per muL in 1995-96 to 269 cells per muL in 1998 but then decreased to around 200 cells per muL. In 1995-96, 58% achieved HIV-1 RNA of 500 copies per mL or less by 6 months compared with 83% in 2002-03. Compared with 1998, adjusted hazard ratios for AIDS were 1.07 (95% CI 0.84-1.36) in 1995-96 and 1.35 (1.06-1.71) in 2002-03. Corresponding figures for death were 0.87 (0.56-1.36) and 0.96 (0.61-1.51). INTERPRETATION Virological response after starting HAART improved over calendar years, but such improvement has not translated into a decrease in mortality.

Normalisation of CD4 counts in patients with HIV-1 infection and maximum virological suppression who are taking combination antiretroviral therapy: an observational cohort study

BACKGROUND Combination antiretroviral therapy (cART) has been shown to reduce mortality and morbidity in patients with HIV. As viral replication falls, the CD4 count increases, but whether the CD4 count returns to the level seen in HIV-negative people is unknown. We aimed to assess whether the CD4 count for patients with maximum virological suppression (viral load <50 copies per mL) continues to increase with long-term cART to reach levels seen in HIV-negative populations. METHODS We compared increases in CD4 counts in 1835 antiretroviral-naive patients who started cART from EuroSIDA, a pan-European observational cohort study. Rate of increase in CD4 count (per year) occurring between pairs of consecutive viral loads below 50 copies per mL was estimated using generalised linear models, accounting for multiple measurements for individual patients. FINDINGS The median CD4 count at starting cART was 204 cells per microL (IQR 85-330). The greatest mean yearly increase in CD4 count of 100 cells per microL was seen in the year after starting cART. Significant, but lower, yearly increases in CD4 count, around 50 cells per microL, were seen even at 5 years after starting cART in patients whose current CD4 count was less than 500 cells per microL. The only groups without significant increases in CD4 count were those where cART had been taken for more than 5 years with a current CD4 count of more than 500 cells per microL, (current mean CD4 count 774 cells per microL; 95% CI 764-783). Patients starting cART with low CD4 counts (<200 cells per microL) had significant rises in CD4 counts even after 5 years of cART. INTERPRETATION Normalisation of CD4 counts in HIV-infected patients for all infected individuals might be achievable if viral suppression with cART can be maintained for a sufficiently long period of time.

Incidence of tuberculosis among HIV-Infected patients receiving highly active antiretroviral therapy in Europe and North America

BACKGROUND We obtained estimates of the incidence of tuberculosis (TB) among patients receiving HAART and identified determinants of the incidence. METHODS We analyzed the incidence of TB during the first 3 years after initiation of HAART among 17,142 treatment-naive, AIDS-free persons starting HAART who were enrolled in 12 cohorts from Europe and North America. We used univariable and multivariable Poisson regression models to identify factors associated with the incidence. RESULTS During the first 3 years (36,906 person-years), 173 patients developed TB (incidence, 4.69 cases per 1000 person-years). In multivariable analysis, the incidence rate was lower for men who have sex with men, compared with injection drug users (relative rate, 2.46; 95% confidence interval [CI], 1.51-4.01), heterosexuals (relative rate, 2.42; 95% CI, 1.64-3.59), those with other suspected modes of transmission (relative rate, 1.66; 95% CI, 0.91-3.06), and those with a higher CD4+ count at the time of HAART initiation (relative rate per log2 cells/microL, 0.87; 95% CI, 0.84-0.91). During 28,846 person-years of follow-up after the first 6 months of HAART, 88 patients developed TB (incidence, 3.1 cases per 1000 person-years of follow-up). In multivariable analyses, a low baseline CD4+ count (relative rate per log2 cells/microL, 0.89; 95% CI, 0.83-0.96), 6-month CD4+ count (relative rate per log2 cells/microL, 0.90; 95% CI, 0.81-0.99), and a 6-month HIV RNA level >400 copies/mL (relative rate, 2.21; 95% CI, 1.33-3.67) were significantly associated with the risk of acquiring TB after 6 months of HAART. CONCLUSION The level of immunodeficiency at which HAART is initiated and the response to HAART are important determinants of the risk of TB. However, this risk remains appreciable even among those with a good response to HAART, suggesting that other interventions may be needed to control the TB epidemic in the HIV-infected population.