Efficacy, safety and pharmacokinetics of atazanavir (200mg twice daily) plus raltegravir (400mg twice daily) dual regimen in the clinical setting.

BACKGROUND: Unboosted atazanavir with raltegravir has been investigated at 300mg twice daily showing frequent hyperbilirubinemia and selection of resistance-associated mutations. OBJECTIVES: Atazanavir 200mg twice daily could increase tolerability and plasma exposure. STUDY DESIGN: Patients on atazanavir/raltegravir (200/400 twice daily), with self-reported adherence >95% and no concomitant interacting drugs were retrospectively evaluated. RESULTS: 102 patients [72.5% male, age 46.4 years (42-54), BMI 24kg/m2 (22-26)] were included. CD4+ T lymphocytes were 417 cell/µL (302-704) and 76 patients (74.5%) had HIV-RNA <50 copies/ml. After 123 weeks 18.6% patients showed virological failure and 3.9% discontinued for intolerance. Available genotypes showed selection of major integrase (7/10 patients) and protease resistance-associated mutations (5/13 patients). In patients switching with dyslipidemia (n=67) total, LDL cholesterol and triglycerides significantly decreased. Patients switching with eCRCL<60ml/min (n=27) had no significant changes while patients with eCRCL >60ml/min showed significant decrease (-9.8ml/min, p=0.003) at 96-weeks. Atazanavir and raltegravir trough concentrations were 321ng/mL (147-720) and 412ng/mL (225-695). Self-reported non-adherence (n=4) was significantly associated with virological failure (p=0.02); patients with virological success had borderline longer previous virological control (33 vs. 18 months, p=0.07). DISCUSSION: Switch to atazanavir/raltegravir was safe and well tolerated allowing optimal drugs' plasma exposure. However, a concerning rate (18.6%) failed with newly selected mutations and stopped ATV/RAL because of DDI and intolerance issues or were lost to follow-up. This regimen might be considered in selected patients, without history of protease inhibitors failure or HBV infection, showing optimal adherence and prolonged suppression.

HIV-1 Very Low Level Viremia Is Associated with Virological Failure in Highly Active Antiretroviral Treatment-Treated Patients.

The aim of this study was to evaluate the impact of HIV-1 very low-level viremia (<50 copies/ml) on the 2-year risk of virological failure. A retrospective analysis including HIV-positive patients presenting two consecutive HIV RNA below 50 copies/ml (outpatient clinic in Italy, first semester of 2010) was performed. HIV RNA was measured through real time polymerase chain reaction (PCR) assay CAP/CTM HIV-1 version 2.0 (detection limit: 20 copies/ml) and stratified as undetectable RNA ("Target Not Detected", TND), <20 copies/ml, 20-50 copies/ml. After 96 weeks virological failure was defined as two consecutive viral loads above 50 copies/ml. Log-rank tests and a multivariate Cox proportional hazard model were used for univariate and multivariate analysis. A total of 1,055 patients (71.4% male, 87.4% white, aged 46.7 years) were included: nadir and current CD4 cell counts were 203 cells/mm(3) (106-292) and 554 cells/mm(3) (413-713.5). HIV RNA was undetectable in 781 patients (74%), <20 copies/ml in 190 patients (18%) and 20-50 copies/ml in 84 patients (8%). Virological failure was observed in 81 patients (7.7%); at multivariate analysis detectable RNA at baseline (p=0.017), HCV infection (p=0.020), more than three pills in the regimen (p=0.003), and duration of HIV RNA <50 copies/ml below 2 years (p<0.001) were independently associated with virological failure. In 14 patients newly selected resistance-associated mutations were observed. Undetectable HIV RNA by real-time PCR is significantly associated with a lower 2-year risk of virological failure along with Ab HCV negativity, longer viral control, and lower pill burden. Studies investigating the management of residual viremia under antiretroviral treatment are warranted.

[Survival, progression to AIDS and immunosuppression in HIV-positive individuals before and after the introduction of the highly active antiretroviral therapy (HAART)]. / Sopravvivenza, progressione in AIDS e livello di immunosoppresione in persone HIV-positive prima e dopo l'introduzione della terapia antiretrovirale di combinazione con tre o più farmaci (HAART).

We evaluated the changes in the progression to death and AIDS and in the mean level of CD4 lymphocytes by calendar period in HIV-positive individuals before and after the introduction of HAART. Through data collected in a prospective cohort study (Italian Seroconversion Study) of 1899 HIV-infected persons with well estimated date of seroconversion, considered as time-zero of analysis, we calculated Kaplan-Meier curves and Cox models, allowing for staggered entries, to estimate the cumulative probability of survival and hazard-ratios (HR) for death and for AIDS by calendar period (1980-1996: pre-HAART era, 1997-1998: first HAART era, and 1999-2001: second HAART era), age at seroconversion, gender, and exposure category. During 17251 person-years, 660 HIV-positive patients developed AIDS and 510 died. Before 1997, the cumulative probability of survival, at twelve years from seroconversion, was 51.0%. In the period 1997-1998 the probability was 77.3% and in the period 1999-2001 it further increased at 91.2%. In the period 1980-1996 only older age at seroconversion was associated with more rapid progression to death. In the period 1987-2001 individuals infected through injecting drug use had a reduced increase of survival compared to those infected through sexual contact. Similar results were obtained for progression to AIDS. Finally we estimated an improved level of immunesuppression in the period 1987-2001. In fact, while in the period 1980-1996 we estimated a decrease of the CD4 lymphocites of -54.8 cells/mm3 (95% CI: -52.0; -57.6) per year; after 1996, we estimated an increase of CD4 of +39.6 (95% CI +34.1; +45.1)per year. This study provides strong evidence that the efficacy of the HAART estimated in the controlled clinical trials has resulted in a real reduction at the population level of morbidity and mortality.