Efficacy, tolerability and risk factors for virological failure of darunavir-based therapy for treatment-experienced HIV-infected patients: the Swiss HIV Cohort Study

Do contemporary antiretrovirals increase the risk of end-stage liver disease? Signals from patients starting therapy in the North American AIDS Cohort Collaboration on Research and Design

PURPOSE

Despite effective antiretroviral therapy, rates of end-stage liver disease (ESLD) remain high. It is not clear whether contemporary antiretrovirals contribute to the risk of ESLD.

METHODS

We included patients from cohorts with validated ESLD data in the North American AIDS Cohort Collaboration on Research and Design. Patients had to initiate antiretroviral therapy after 1 January 2004 with a nucleos(t)ide backbone of either abacavir/lamivudine or tenofovir/emtricitabine and a contemporary third (anchor) drug. Patients were followed until a first ESLD event, death, end of a cohort's ESLD validation period, loss to follow-up or 31 December 2015. We estimated associations between cumulative exposure to each drug and ESLD using a hierarchical Bayesian survival model with weakly informative prior distributions.

RESULTS

Among 10 564 patients included from 12 cohorts, 62 had an ESLD event. Of the nine anchor drugs, boosted protease inhibitors atazanavir and darunavir had the strongest signals for ESLD, with increasing hazard ratios (HR) and narrowing credible intervals (CrI), from a prior HR of 1.5 (95% CrI 0.32-7.1) per 5 year's exposure to posterior HRs respectively of 1.8 (95% CrI 0.82-3.9) and 2.0 (95% CrI 0.86-4.7). Both backbones and efavirenz showed no signal. Hepatitis C coinfection was the most important covariate risk factor (HR 4.4, 95% CrI 2.6-7.0).

CONCLUSIONS

While contemporary antiretrovirals pose less risk for ESLD than hepatitis coinfection, atazanavir and darunavir had a toxicity signal. We show how hierarchical Bayesian modelling can be used to detect toxicity signals in cohort event monitoring data even with complex treatments and few events.

Long-term virological effectiveness with darunavir/ritonavir-based salvage therapy in people living with HIV/AIDS from São Paulo, Brazil

Even though darunavir/ritonavir (DRV/r) has high potency and a greater genetic barrier, there are few studies on the long-term effectiveness of DRV/r-based salvage therapy in people living with HIV (PLWH) in low and middle-income countries. This retrospective cohort study, from São Paulo, Brazil, included ART-experienced PLWH aged ≥18 years with virological failure (VF) who had started DRV/r plus an optimized background regimen (OBR) between 2008 and 2012. The proportion of patients with viral load (VL) <50 copies/mL, the improved mean CD4+ T cell count and the factors associated with VF during the 144-week follow-up were assessed. The study included 173 patients with the following characteristics [median (interquartile range)]: age 48 (42 -53) years; CD4+ T cell count, 229 (89 -376) cells/mm3; VL, 4.26 (3.70 -4.74) log10; 6 (4 -7) previous regimens; and 100 (38 -156) months of VF. After 144 weeks, 129 (75%) patients had VL< 50 copies/mL and a mean increase in the CD4+ T cell count of 190 cells/mm3. VL>100,000 copies/mL and poor adherence were associated with VF. DRV/r plus an OBR showed high long-term virological suppression and immunological recovery. VL>100,000 copies/mL and poor adherence were associated with VF at 144 weeks.

Risk Factors for Hepatitis C Virus Reinfection After Sustained Virologic Response in Patients Coinfected With HIV

Background.

Highly effective hepatitis C virus (HCV) therapies have spurred a scale-up of treatment to populations at greater risk of reinfection after sustained virologic response (SVR). Reinfection may be higher in HIV–HCV coinfection, but prior studies have considered small selected populations. We assessed risk factors for reinfection after SVR in a representative cohort of Canadian coinfected patients in clinical care.

Methods.

All patients achieving SVR after HCV treatment were followed with HCV RNA measurements every 6 months in a prospective cohort study. We used Bayesian Cox regression to estimate reinfection rates according to patient reported injection drug use (IDU) and sexual activity among men who have sex with men (MSM).

Results.

Of 497 patients treated for HCV, 257 achieved SVR and had at least 1 subsequent RNA measurement. During 589 person-years of follow-up (PYFU) after SVR, 18 (7%) became HCV RNA positive. The adjusted reinfection rate (per 1000 PYFU) in the first year after SVR was highest in those who reported high-frequency IDU (58; 95% credible interval [CrI], 18–134) followed by MSM reporting high-risk sexual activity (26; 95% CrI, 6–66) and low-frequency IDU (22; 95% CrI, 4–68). The rate in low-risk MSM (16; 95% CrI, 4–38) was similar to that in reference patients (10; 95% CrI, 4–20). Reinfection rates did not diminish with time.

Conclusions.

HCV reinfection rates varied according to risk. Measures are needed to reduce risk behaviors and increase monitoring in high-risk IDU and MSM if HCV elimination targets are to be realized.

The effectiveness of daclatasvir based therapy in European patients with chronic hepatitis C and advanced liver disease

Background

There is limited evidence for the effectiveness of daclatasvir in patients whose hepatitis C threatens their life expectancy. The Named Patient Program in Europe included patients with advanced chronic hepatitis C, a life expectancy of less than 12 months and no other treatment options.

Methods

A retrospective multi-country cohort of patients with chronic hepatitis C who received daclatasvir as part of the Named Patient Program in Austria, Denmark, Spain, Sweden, Switzerland and the United Kingdom. Treatment response was defined as a sustained virologic response (unquantifiable hepatitis C RNA) at 12 weeks post treatment. We summarised the characteristics of the patients in this cohort and estimated the rate of sustained virologic response for patients receiving daclatasvir and sofosbuvir with or without ribavirin using hierarchical Bayesian modelling.

Results

The 249 patients included had a median age of 56 years; most were male (78%), hepatitis C genotype 1 (75%), treatment experienced (65%) and with decompensated cirrhosis (59%). Many had had a liver transplant before receiving daclatasvir (40%). Of the 249 patients, 242 patients received daclatasvir and sofosbuvir and either reached 12 weeks post treatment or died during (n = 9) or after treatment (n = 4) or were lost to follow up during treatment (n = 1). The estimated rate of sustained virologic response at 12 weeks post treatment was 87% (95% credible interval 75 to 94%) for previously treated genotype 1 patients with decompensated cirrhosis.

Conclusions

Daclatasvir with sofosbuvir is an effective treatment in clinical practice for hepatitis C genotype 1 patients with decompensated cirrhosis.

Electronic supplementary material

The online version of this article (doi:10.1186/s12879-016-2106-x) contains supplementary material, which is available to authorized users.

Virological failure at one year in triple-class experienced patients switching to raltegravir-based regimens is not predicted by baseline factors

We evaluated rates and determinants of virological failure in triple-class experienced patients receiving raltegravir-based regimens from a national observational study over 48 weeks, defined by any one of the following: (1) no HIV-RNA suppression to undetectable levels (<50 copies/mL) during follow-up; (2) detectable viral load after obtaining undetectable levels; and (3) leaving the study before 48 weeks. Among 101 eligible patients, 26 (25.7%; 95% CI 17.2–34.2) had virological failure. No significant differences between patients with and without virological failure were observed for gender, age, route of transmission, baseline CD4/HIV-RNA, CDC group, hepatitis B or C co-infections, resistance (based on the last genotype available), type and number of concomitant drug classes, concomitant use of darunavir, atazanavir, etravirine, enfuvirtide or maraviroc, and health-related quality-of-life measures. A high rate of treatment response was observed. The analyses did not identify any baseline factor associated with failure, including resistance status. Even if we cannot exclude the presence of pre-existing minority resistant variants not captured by genotypic tests, the lack of baseline predictors of failure suggests the need to monitor patients closely during follow up for other factors, such as potential drug interactions and reduced levels of adherence, which may favour virological failure.

Long-term clinical experience with darunavir (2007-2015) in a large cohort of HIV-infected patients in Spain

The clinical experience with the protease inhibitor darunavir/ritonavir (DRV/r) was retrospectively evaluated in a cohort of 173 HIV+ patients who initiated antiretroviral treatment including DRV/r (period 2007-2015). The 43.2% had a CD4 nadir ≤100 cells/mm³ , 64.1% were treatment-experienced, and 36.5% had failed to >3 lines of antiretroviral therapy. Nonetheless, the rate of virological suppression (HIV-RNA <50 copies/ml) in naïve patients was 63%, 66.7%, and 63.6% at 48, 96, and 144 weeks, respectively. The rate of virological suppression in treatment-experienced patients was 62.7%, 78.7%, and 79.1% at 48, 96, and 144 weeks, respectively. No differences were observed according to the immunovirological status neither dosage of DRV/r. Most of them (82.6%) maintained DRV/r treatment. Causes for DRV/r discontinuation were mainly gastrointestinal and cutaneous adverse events (10.5%), switch to simplification treatment strategies (3.5%) and virological failure (1.7%). These findings demonstrate the prolonged efficacy and tolerability of DRV/r even in multi-treated HIV+ patients with an unfavorable immunovirological status. J. Med. Virol. 88:2125-2131, 2016. © 2016 Wiley Periodicals, Inc.

Improved darunavir genotypic mutation score predicting treatment response for patients infected with HIV-1 subtype B and non-subtype B receiving a salvage regimen

OBJECTIVES

The objective of this study was to improve the prediction of the impact of HIV-1 protease mutations in different viral subtypes on virological response to darunavir.

METHODS

Darunavir-containing treatment change episodes (TCEs) in patients previously failing PIs were selected from large European databases. HIV-1 subtype B-infected patients were used as the derivation dataset and HIV-1 non-B-infected patients were used as the validation dataset. The adjusted association of each mutation with week 8 HIV RNA change from baseline was analysed by linear regression. A prediction model was derived based on best subset least squares estimation with mutational weights corresponding to regression coefficients. Virological outcome prediction accuracy was compared with that from existing genotypic resistance interpretation systems (GISs) (ANRS 2013, Rega 9.1.0 and HIVdb 7.0).

RESULTS

TCEs were selected from 681 subtype B-infected and 199 non-B-infected adults. Accompanying drugs were NRTIs in 87%, NNRTIs in 27% and raltegravir or maraviroc or enfuvirtide in 53%. The prediction model included weighted protease mutations, HIV RNA, CD4 and activity of accompanying drugs. The model's association with week 8 HIV RNA change in the subtype B (derivation) set was R(2) = 0.47 [average squared error (ASE) = 0.67, P < 10(-6)]; in the non-B (validation) set, ASE was 0.91. Accuracy investigated by means of area under the receiver operating characteristic curves with a binary response (above the threshold value of HIV RNA reduction) showed that our final model outperformed models with existing interpretation systems in both training and validation sets.

CONCLUSIONS

A model with a new darunavir-weighted mutation score outperformed existing GISs in both B and non-B subtypes in predicting virological response to darunavir.

Emergence of Acquired HIV-1 Drug Resistance Almost Stopped in Switzerland: A 15-Year Prospective Cohort Analysis

BACKGROUND

Drug resistance is a major barrier to successful antiretroviral treatment (ART). Therefore, it is important to monitor time trends at a population level.

METHODS

We included 11 084 ART-experienced patients from the Swiss HIV Cohort Study (SHCS) between 1999 and 2013. The SHCS is highly representative and includes 72% of patients receiving ART in Switzerland. Drug resistance was defined as the presence of ≥1 major mutation in a genotypic resistance test. To estimate the prevalence of drug resistance, data for patients with no resistance test was imputed based on the patient's risk of harboring drug-resistant viruses.

RESULTS

The emergence of new drug resistance mutations declined dramatically from 401 to 23 patients between 1999 and 2013. The upper estimated prevalence limit of drug resistance among ART-experienced patients decreased from 57.0% in 1999 to 37.1% in 2013. The prevalence of 3-class resistance decreased from 9.0% to 4.4% and was always <0.4% for patients who initiated ART after 2006. Most patients actively participating in the SHCS in 2013 with drug-resistant viruses initiated ART before 1999 (59.8%). Nevertheless, in 2013, 94.5% of patients who initiated ART before 1999 had good remaining treatment options based on Stanford algorithm.

CONCLUSIONS

Human immunodeficiency virus type 1 drug resistance among ART-experienced patients in Switzerland is a well-controlled relic from the era before combination ART. Emergence of drug resistance can be virtually stopped with new potent therapies and close monitoring.

Effectiveness and risk factors for virological outcome of darunavir-based therapy for treatment-experienced HIV-infected patients

OBJECTIVE

We evaluated the effectiveness of darunavir (DRV) treatment plus an optimized background regimen in 120 HIV-1 treatment-experienced patients.

DESIGN

Retrospective cohort, multicenter study.

METHODS

Adults >16 years with virological treatment failure starting therapy with a DRV-containing regimen were included. Effectiveness was evaluated as the percentage of patients with an undetectable HIV-1 RNA viral load (<50 and <200 copies/mL) after 48 weeks, and changes in CD4+ cell counts. We evaluated the risk factors associated with treatment failure.

RESULTS

Of the cohort, 83 % were men with a median age of 45 years (interquartile range, IQR 40-51). They had experienced treatment for a median of 13 years (IQR 9-17) with a median of six previous regimens (IQR 4-7), all using protease inhibitors. After treatment, 82 % (95 % confidence interval, CI 74-88 %) of patients had an HIV-1 RNA viral load <200 copies/mL and 69 % (95 % CI 60-76 %) had <50 copies/mL. The CD4+ cell count increased by 378 cells/μL (IQR 252-559; P < 0.001 vs. baseline). Risk factors associated with poor outcome were age >40 years [odds ratio, OR 0.15 (95 % CI 0.10-0.78); P = 0.015], use of raltegravir in the regimen [OR 0.37 (95 % CI 0.10-0.97); P = 0.046], and baseline CD4+ cell count <200 cells/μL [OR 2.79 (95 % CI 1.11-6.97); P = 0.028].

CONCLUSION

In this Mexican cohort Darunavir was metabolically safe, well tolerated and achieved high rates of virological suppression in highly treatment-experienced patients infected with HIV-1.

Short communication: Effectiveness at 48 weeks of switching from enfuvirtide to raltegravir in virologically suppressed multidrug-resistant HIV type 1-infected patients in a Brazilian cohort

The effectiveness of switching from enfuvirtide to raltegravir in HIV-1-infected patients on a suppressive antiretroviral regimen has been poorly studied in the clinical practice of developing countries. We conducted a multicenter retrospective cohort study in HIV-1-infected, multidrug-experienced adults (≥18 years old) with plasma HIV-1-RNA <400 copies/ml for at least 4 months on an enfuvirtide-containing therapy between 2005 and 2010, in whom the attending physician switched from enfuvirtide to raltegravir. Effectiveness endpoints were measured at week 48 after switch. Analyses were conducted on an intent-to-treat basis and two strategies for handling missing outcome data were used (hereafter, strategies 1 and 2). Overall, 87 patients were eligible for analysis. At baseline, the median CD4(+) T cell count was 400 cells/μl and 91.9% of patients had <50 HIV-1-RNA copies/ml. At week 48, the proportions of patients with plasma HIV-1-RNA <50 and <400 copies/ml were, respectively, 86.2% (95% CI=77.1; 92.7%) and 88.5% (95% CI=79.9; 94.3%) (strategies 1 and 2) and 89.7% (95% CI=81.3; 95.2%) and 90.8% (95% CI=82.7; 95.9%) (strategies 1 and 2). This was a -10.3% (95% CI=-2.8; -17.9%) and -9.2% (95% CI=-2; -16.4%) difference from baseline in the proportion of patients with plasma HIV-1-RNA <400 copies/ml. The median increase in CD4(+) T cell counts was 41 and 64 cells/μl (p<0.001) (strategies 1 and 2). No patient withdrew raltegravir or developed opportunistic infections, but one was diagnosed with HIV-related dementia. In conclusion, switching from enfuvirtide to raltegravir in patients on a virologically suppressive regimen is an effective strategy even in a Brazilian clinical setting.

Virologic and immunologic effectiveness of darunavir-based salvage therapy in HIV-1-infected adults in a Brazilian clinical practice setting: results of a multicenter and retrospective cohort study

Background

Darunavir has been proven efficacious for antiretroviral-experienced HIV-1-infected patients in randomized trials. However, effectiveness of darunavir-based salvage therapy is understudied in routine care in Brazil.

Methods

Retrospective cohort study of HIV-1-infected patients from three public referral centers in Belo Horizonte, who received a darunavir-based therapy between 2008 and 2010, after virologic failure. Primary endpoint was the proportion of patients with viral load < 50 copies/mL at week 48. Change in CD4 cell count was also evaluated. Outcome measures were analyzed on an intent-to-treat basis applied to observational studies. Sensitivity analysis was conducted to evaluate the impact of missing data at week 48. Predictors of virologic failure were examined using rare-event, finite sample, bias-corrected logistic regression.

Results

Among 108 patients, the median age was 44.2 years, and 72.2% were male. They had long-standing HIV-1 infection (median 11.6 years) and advanced disease (76.9% had an AIDS-defining event). All patients had previously received protease inhibitors and nucleoside reverse transcriptase inhibitors, 75% nonnucleoside reverse transcriptase inhibitors, and 4.6% enfuvirtide. The median length of protease inhibitor use was 8.9 years, and 90.8% of patients had prior exposure to unboosted protease inhibitor. Genotypic resistance profile showed a median of three primary protease inhibitor mutations and 10.2% had three or more darunavir resistance-associated mutations. Virologic success at week 48 was achieved by 78.7% (95% CI = 69.7–86%) of patients and mean CD4 cell count increase from baseline was 131.5 cells/μL (95% CI = 103.4–159.6). In multiple logistic regression analysis, higher baseline viral load (RR = 1.04 per 10,000 copies/mL increase; 95% CI = 1.01–1.09) and higher number of darunavir resistance-associated mutations (RR = 1.23 per each; 95% CI = 0.95–1.48) were independently associated with virologic failure.

Conclusion

Virologic suppression is a realistic endpoint for most treatment-experienced patients who begin a darunavir-based therapy outside the controlled conditions of a randomized trial, at routine care settings.

Virologic and Immunologic Effectiveness at 48 Weeks of Darunavir–Ritonavir-Based Regimens in Treatment-Experienced Persons Living with HIV-1 Infection in Clinical Practice

Introduction:

Published data addressing the effectiveness of darunavir–ritonavir (DRV/r)-based therapy for multiexperienced patients in developing countries are scarce. This study evaluated the 48-week virologic and immunologic effectiveness of salvage therapy based on DRV/r for the treatment of multidrug-experienced HIV-1-infected adults in Brazil.

Materials and Methods:

A multicenter retrospective cohort study was carried out with multidrug-experienced adults who were on a failing antiretroviral therapy and started a DRV/r-based salvage therapy between 2008 and 2010. The primary effectiveness end point was the proportion of patients with virologic success (plasma HIV-1 RNA <50 copies/mL at week 48).

Results:

At 48 weeks, 73% of the patients had HIV-RNA <50 copies/mL and a mean increase of 108 CD4 cells/mm3. Higher baseline viral load, lower baseline CD4 count, younger age, and 3 or more DRV/r-associated resistance mutations were significantly predictive of virologic failure. Concomitant use of raltegravir was strongly associated with virologic success.

Conclusion:

The use of DRV/r-based regimens for salvage therapy is an effective strategy in the clinical care setting of a developing country.