A new time-dependent approach for assessment of the impact of invasive aspergillosis shows effect on short- but not on long-term survival of patients with AML or high-risk MDS

Effect of invasive aspergillosis on risk for different causes of death in older patients with acute myeloid leukaemia or high-risk myelodysplastic syndrome

PURPOSE

Study objectives were to estimate the cumulative incidence of death due to different causes of death (CODs) and investigate the effect of invasive aspergillosis (IA) on each separate COD in a cohort of older patients with acute myeloid leukaemia (AML) or high-risk myelodysplastic syndrome (MDS) included in the Haemato-Oncology Foundation for Adults in the Netherlands (HOVON) 43 randomized controlled trial.

METHODS

Pre-collected data from the trial was obtained from the HOVON data center and relevant clinical information was extracted. The cumulative incidence of death due to different CODs was estimated with a competing risk model and the association between each COD and prognostic factors, including IA, were investigated with a cause-specific hazard Cox regression model.

RESULTS

In total 806 patients were included, mean age of 70 years and 55% were male. The cumulative incidences of death due to leukaemia or infection at 3, 6, 12 and 36 months were 0.06, 0.11, 0.23, 0.42 and 0.17, 0.19, 0.22, 0.25 respectively. Incidence of IA was 21% and diagnosis of IA up until the final chemotherapy cycle was associated with an increased risk of dying from leukaemia (cause-specific hazard ratio (_CSHR): 1.75, 95% CI 1.34-2.28) and a trend was seen for infection (_CSHR: 1.36, 95% CI 0.96-1.91).

CONCLUSION

Leukaemia was the most likely cause of death over time, however in the first year after diagnosis of AML or high-risk MDS infection was the most likely cause of death. Patients with IA had a relatively increased risk of dying from leukaemia or infection.

Combined Impact of Inflammation and Pharmacogenomic Variants on Voriconazole Trough Concentrations: A Meta-Analysis of Individual Data

Few studies have simultaneously investigated the impact of inflammation and genetic polymorphisms of cytochromes P450 2C19 and 3A4 on voriconazole trough concentrations. We aimed to define the respective impact of inflammation and genetic polymorphisms on voriconazole exposure by performing individual data meta-analyses. A systematic literature review was conducted using PubMed to identify studies focusing on voriconazole therapeutic drug monitoring with data of both inflammation (assessed by C-reactive protein level) and the pharmacogenomics of cytochromes P450. Individual patient data were collected and analyzed in a mixed-effect model. In total, 203 patients and 754 voriconazole trough concentrations from six studies were included. Voriconazole trough concentrations were independently influenced by age, dose, C-reactive protein level, and both cytochrome P450 2C19 and 3A4 genotype, considered individually or through a combined genetic score. An increase in the C-reactive protein of 10, 50, or 100 mg/L was associated with an increased voriconazole trough concentration of 6, 35, or 82%, respectively. The inhibitory effect of inflammation appeared to be less important for patients with loss-of-function polymorphisms for cytochrome P450 2C19. Voriconazole exposure is influenced by age, inflammatory status, and the genotypes of both cytochromes P450 2C19 and 3A4, suggesting that all these determinants need to be considered in approaches of personalization of voriconazole treatment.

Optimization of voriconazole therapy for treatment of invasive aspergillosis: Pharmacogenomics and inflammatory status need to be evaluated

AIMS

Cytochrome 2C19 genotype-directed dosing of voriconazole (VRC) reduces the incidence of insufficient VRC trough concentrations (C_min ) but does not account for CYP3A polymorphisms, also involved in VRC metabolism. This prospective observational study aimed to evaluate the utility of a genetic score combining CYP2C19 and CYP3A genotypes to predict insufficient initial VRC C_min (<1 mg/L).

METHODS

The genetic score was determined in hematological patients treated with VRC. The higher the genetic score, the faster the metabolism of the patient. The impact of the genetic score was evaluated considering initial VRC C_min and all VRC C_min (n = 159) determined during longitudinal therapeutic drug monitoring.

RESULTS

Forty-three patients were included, of whom 41 received VRC for curative indication. Thirty-six patients had a genetic score ≥2, of whom 11 had an initial insufficient VRC C_min . A genetic score ≥2 had a positive predictive value of 0.31 for having an initial insufficient VRC C_min and initial VRC C_min was not associated with the genetic score. The lack of association between the genetic score and VRC C_min may be related to the inflammatory status of the patients (C-reactive protein [CRP] levels: median [Q1-Q3]: 43.0 [11.0-110.0] mg/L), as multivariate analysis performed on all VRC C_min identified CRP as an independent determinant of the VRC C_min adjusted for dose (P < .0001).

CONCLUSION

The combined genetic score did not predict low VRC exposure in patients with inflammation, which is frequent in patients with invasive fungal infections. Strategies for the individualization of VRC dose should integrate the inflammatory status of patients in addition to pharmacogenetic variants.

Inflammation is a potential risk factor of voriconazole overdose in hematological patients

Voriconazole (VRC) overdoses are frequent and expose patients at high risk of adverse effects. This case-control study performed in hematological patients who benefited from VRC therapeutic drug monitoring from January 2012 to December 2015 aimed to identify risk factors of VRC overdose. Pharmacogenetic, biological, and demographic parameters at the time of VRC trough concentration (C_min ) were retrospectively collected from medical records. Cases (VRC overdose: defined by a VRC C_min ≥ 4 mg/L; n = 31) were compared to controls (no VRC overdose: defined by VRC C_min < 4 mg/L; n = 31) using nonparametric or chi-square tests followed by multivariable analysis. VRC overdoses were significantly associated with high CRP and bilirubin levels, intravenous administration, and age in univariable analysis. In contrast, the proportion of CYP genotypes (CYP2C19, CYP3A4, or CYP3A5, considered alone or combined in a combined genetic score) were not significantly different between patients who experienced a VRC overdose and those who did not. In multivariable analysis, the class of CRP level (defined by median CRP levels of 96 mg/L) was the sole independent risk factor of VRC overdose (P < 0.01). Patients with CRP levels > 96 mg/L) had a 27-fold (IC 95%: [6-106]) higher risk of VRC overdose than patients with CRP levels ≤ 96 mg/L. This study demonstrates that inflammatory status, assessed by CRP levels, is the main risk factor of VRC overdose in French hematological patients, whereas pharmacogenetic determinants do not appear to be involved.

Managing invasive aspergillosis in haematological patients in the era of resistance polymerase chain reaction and increasing triazole resistance: A modelling study of different strategies

OBJECTIVES

Triazole resistance in Aspergillus spp. is emerging and complicates prophylaxis and treatment of invasive aspergillosis (IA) worldwide. New polymerase chain reaction (PCR) tests on broncho-alveolar lavage (BAL) fluid allow for detection of triazole resistance at a genetic level, which has opened up new possibilities for targeted therapy. In the absence of clinical trials, a modelling study delivers estimates of the added value of resistance detection with PCR, and which empiric therapy would be optimal when local resistance rates are known.

DESIGN

A decision-analytic modelling study was performed based on epidemiological data of IA, extended with estimated dynamics of resistance rates and treatment effectiveness. Six clinical strategies were compared that differ in use of PCR diagnostics (used vs not used) and in empiric therapeutic choice in case of unknown triazole susceptibility: voriconazole, liposomal amphotericin B (LAmB) or both. Outcome measures were proportion of correct treatment, survival and serious adverse events.

RESULTS

Implementing aspergillus PCR tests was projected to result in residual treatment-susceptibility mismatches of <5% for a triazole resistance rate up to 20% (using voriconazole). Empiric LAmB outperformed voriconazole at resistance rates >5-20%, depending on PCR use and estimated survival benefits of voriconazole over LAmB. Combination therapy of voriconazole and LAmB performed best at all resistance rates, but the advantage over the other strategies should be weighed against the expected increased number of drug-related serious adverse events. The advantage of combination therapy over LAmB monotherapy became smaller at higher triazole resistance rates.

CONCLUSIONS

Introduction of current aspergillus PCR tests on BAL fluid is an effective way to increase the proportion of patients that receive targeted therapy for IA. The results indicate that close monitoring of background resistance rates and adverse drug events are important to attain the potential benefits of LAmB. The choice of strategy ultimately depends on the probability of triazole resistance, the availability of PCR and individual patient characteristics.

The burden of Invasive Aspergillosis in patients with haematological malignancy: A meta-analysis and systematic review

INTRODUCTION

Successful treatment of haematological malignancies is frequently complicated by Invasive Aspergillosis (IA), a life-threatening fungal infection that occurs in at least 10% of haemato-oncological patients. Case fatality rates (CFR) may fluctuate over time, depending on host pathogen interactions as well as on treatment and quality of patient care. We conducted a systematic review and metaanalysis of current - i.e. 2008-revised EORTC-MSG criteria era - incidence and case fatality rates (CFR) of IA in patients with haematological malignancy.

METHODS

A systematic search according to PRISMA guidelines was performed to identify all literature reporting populations with a haematological malignancy and the incidence of IA, defined according to the EORTC/MSG 2008 criteria. Pooled cumulative incidences and CFR within 100 days were estimated using a random effects model for predefined patient populations and stratified by use of prophylaxis.

RESULTS

The systematic literature search yielded 1285 publications of which n = 49 met the inclusion criteria. Overall, 16.815 patients were involved of which 1056 (6.3%) developed IA. IA risk ranged from 4% (during remission-induction, with prophylaxis) to 11% (during remission-induction, without prophylaxis). Antifungal prophylaxis was associated with a lower rate of IA, especially in the pre-HSCT population. The pooled CFR within 100 days was 29% (95% CI: 20-38%).

DISCUSSION

This study confirms that IA is a relevant threat in the treatment of haematological cancer despite the universal use of antifungal prophylaxis. These outcomes inform scientists and other stakeholders about the current burden of IA and may be used to direct, implement and improve antifungal stewardship programs.

Molecular Tools for the Detection and Deduction of Azole Antifungal Drug Resistance Phenotypes in Aspergillus Species

The incidence of azole resistance in Aspergillus species has increased over the past years, most importantly for Aspergillus fumigatus. This is partially attributable to the global spread of only a few resistance alleles through the environment. Secondary resistance is a significant clinical concern, as invasive aspergillosis with drug-susceptible strains is already difficult to treat, and exclusion of azole-based antifungals from prophylaxis or first-line treatment of invasive aspergillosis in high-risk patients would dramatically limit drug choices, thus increasing mortality rates for immunocompromised patients. Management options for invasive aspergillosis caused by azole-resistant A. fumigatus strains were recently reevaluated by an international expert panel, which concluded that drug resistance testing of cultured isolates is highly indicated when antifungal therapy is intended. In geographical regions with a high environmental prevalence of azole-resistant strains, initial therapy should be guided by such analyses. More environmental and clinical screening studies are therefore needed to generate the local epidemiologic data if such measures are to be implemented on a sound basis. Here we propose a first workflow for evaluating isolates from screening studies, and we compile the MIC values correlating with individual amino acid substitutions in the products of cyp51 genes for interpretation of DNA sequencing data, especially in the absence of cultured isolates.