Posaconazole vs. fluconazole or itraconazole prophylaxis in patients with neutropenia

Considerations in the approach to invasive fungal infection in patients with haematological malignancies

Invasive infections because of opportunistic yeasts and moulds have contributed significantly to the morbidity and mortality associated with potentially curative treatment for haematological malignancies. Many risk factors have been identified that permit the clinician to predict the likelihood of these infections. The diagnostic process involves maintaining a high index of suspicion based upon an understanding of the clinical circumstances under which invasive fungal infections occur, of the spectrum of fungal syndromes, and of the advantages and limitations of diagnostic testing strategies now available. Treatment strategies may be categorized as prophylactic, pre-emptive, empiric, or directed based upon the circumstances. The therapeutic options have increased in recent years but are not applicable to all clinical circumstances. These considerations are discussed.

Evolving strategies in the management of aspergillosis

Aspergillus spp. remain the most common causes of invasive mould infections among patients with hematologic malignancies and recipients of solid-organ and hematopoietic stem-cell transplants. Despite advances in prevention and treatment, invasive aspergillosis continues to be a deadly disease. This paper reviews current approaches to treatment of aspergillosis in adults, including surgical and immune-based strategies, and developments in prophylaxis for aspergillosis in high-risk patient populations.

Management of Candida infections in the adult intensive care unit

The epidemiology of Candida infection in intensive care units (ICUs) and the management strategies for such infections in non-neutropenic intensive care patients are discussed in this review. Candida species are one of the leading causes of nosocomial bloodstream infections and a significant cause of morbidity in patients admitted to the ICU. Prophylactic, pre-emptive and empiric treatment strategies for Candida infections have been explored in ICU patients. Routine prophylaxis should not be administered to the whole population of ICU patients, because the concerns about the selection of azole-resistant Candida strains or the induction of resistance are justified. Treatment of fungal infections is now possible with newer antifungal agents, including newer azoles (e.g., voriconazole, posaconazole) and echinocandins (e.g., micafungin, anidulafungin). However, there is a critical need for improvement in diagnosis of invasive Candida infection in order to provide clinicians the opportunity to intervene earlier in the diseases course.

Posaconazole against Candida glabrata isolates with various susceptibilities to fluconazole

We investigated the in vitro activities of posaconazole (POS), fluconazole (FLC), amphotericin B (AMB), and caspofungin (CAS) against four clinical isolates of Candida glabrata with various susceptibilities to FLC (FLC MICs ranging from 1.0 to >64 microg/ml). POS MICs ranged from < or =0.03 to 0.5 microg/ml; AMB MICs ranged from 0.25 to 2.0 microg/ml, while CAS MICs ranged from 0.03 to 0.25 microg/ml. When FLC MICs increased, so did POS MICs, although we did not observe any isolate with a POS MIC greater than 0.5 mug/ml. Time-kill experiments showed that POS, FLC, and CAS were fungistatic against all isolates, while AMB at eight times the MIC was fungicidal against three out of four isolates of C. glabrata tested. Then, we investigated the activity of POS in an experimental model of disseminated candidiasis using three different isolates of C. glabrata: one susceptible to FLC (S; FLC MICs ranging from 1.0 to 4.0 microg/ml; POS MIC of < or =0.03 microg/ml), one susceptible in a dose-dependent manner (SDD; FLC MICs ranging from 32 to 64 microg/ml; POS MICs ranging from 0.125 to 0.25 microg/ml), and another one resistant to FLC (R; FLC MIC of >64 microg/ml; POS MIC of 0.5 microg/ml). FLC significantly reduced the kidney burden of mice infected with the S strain (P = 0.0070) but not of those infected with the S-DD and R strains. POS was significantly effective against all three isolates at reducing the kidney fungal burden with respect to the controls (P ranging from 0.0003 to 0.029). In conclusion, our data suggest that POS may be a useful option in the management of systemic infections caused by C. glabrata. Additionally, the new triazole may be a therapeutic option in those cases where an FLC-resistant isolate is found to retain a relatively low POS MIC.

Aggressive cutaneous squamous cell carcinoma associated with prolonged voriconazole therapy in a renal transplant patient

A 69-year-old man, with a history of end-stage renal disease due to polyarteritis nodosa, followed by invasive pulmonary aspergillosis secondary to cyclophosphamide and corticosteroids, received a renal transplant 2 years ago under prophylactic treatment with voriconazole. Because of the severity of the aspergillosis, it was decided to continue voriconazole for a prolonged period. Eighteen months after transplantation, the patient developed a severe facial phototoxic reaction. A few months later, he developed multiple actinic keratoses and a large, rapidly expanding, poorly differentiated squamous cell carcinoma (SCC) with perineural invasion and metastatic lymph nodes, necessitating radical surgery and radiotherapy. Voriconazole therapy has been suggested to be involved in the development of multi-focal invasive SCC when complicated by a phototoxic reaction. Therefore, an alternative antifungal prophylaxis regimen (for instance with posaconazole) should be considered when evaluating patients for solid organ transplantation who are at high risk for the development of cutaneous malignancies.

Is there a serious risk of resistance development to azoles among fungi due to the widespread use and long-term application of azole antifungals in medicine?

It is well known that development of antibiotic resistance in bacteria is not a matter of if but of when. Recently, azoles have been recommended for long-term prophylaxis of invasive fungal infections; hence, it could be argued that fungi also will become resistant to these agents. However, fungi are different from bacteria in several critical points. Bacteria display several resistance mechanisms: alteration of the target, limited access to the target and modification/inactivation of the antibacterial compound. In fungi some mechanisms of resistance to azoles are also known; with azoles for example, alterations of the 14alpha-demethylase target, as well as efflux pumps. It has been observed that these phenotypes develop in yeast populations either due to mutations or to selection processes. However, enzymes which destroy azoles are not found. Furthermore, a horizontal transfer of genes coding resistance traits does not occur in fungi, which means that an explosive expansion of resistances is unlikely to occur, especially in moulds. Indeed, in epidemiologic studies on human and environmental isolates there is convincing evidence that azole resistance is quite uncommon.

Aspergillus calidoustus sp. nov., causative agent of human infections previously assigned to Aspergillus ustus

Aspergillus ustus is a relatively rare human pathogen causing invasive infections in immunocompromised hosts. In this study isolates originating from clinical and other sources have been examined using molecular, morphological, and physiological approaches to clarify their species assignment. Phylogenetic analysis of partial beta-tubulin, calmodulin, actin, and intergenic transcribed spacer sequences indicated that none of the clinical isolates recognized previously as A. ustus belongs to this species. All but two of these isolates formed a well-defined clade related to A. pseudodeflectus based on sequence analysis of protein-coding regions. Morphological and physiological examination of these isolates indicated that they are able to grow above 37 degrees C, in contrast with A. ustus isolates, and give a positive Ehrlich reaction, in contrast with related species including A. granulosus, A. ustus, and A. pseudodeflectus. These isolates are proposed as a new species, A. calidoustus. Antifungal susceptibility testing showed that this species has decreased susceptibilities to several antifungal drugs. The triazoles are inactive in vitro, including the new azole posaconazole.

Pharmacokinetics of oral posaconazole in allogeneic hematopoietic stem cell transplant recipients with graft-versus-host disease

STUDY OBJECTIVE

To analyze the pharmacokinetics of posaconazole administered as prophylaxis for invasive fungal infections in recipients of hematopoietic stem cell transplants (HSCTs) who have graft-versus-host disease (GVHD).

DESIGN

Pharmacokinetic analysis in a subset of posaconazole-treated patients from a large, multicenter, phase III, randomized, double-blind, double-dummy, parallel-group trial that compared posaconazole with fluconazole.

SETTING

Ninety international medical centers.

PATIENTS

The subset of patients comprised 246 HSCT recipients for whom pharmacokinetic data were available.

INTERVENTION

All patients received posaconazole 200 mg oral suspension 3 times/day for a maximum of 16 weeks.

MEASUREMENTS AND MAIN RESULTS

Blood samples were collected after dosing on day 2; at weeks 2, 4, 8, and 12; and on the last day of oral treatment. After patients had received posaconazole for at least 7 days (i.e., after achieving steady state), both maximum observed posaconazole concentration (C(max)) and average posaconazole concentration (C(av)) were determined. Five patients developed invasive fungal infections while receiving treatment. Median C(av) and C(max) were 611 and 635 ng/ml, respectively, in these five patients and were 922 and 1360 ng/ml, respectively, in the 241 patients without invasive fungal infection. In patients without invasive fungal infection, posaconazole concentrations were not clinically affected by race, body weight, or age. Median plasma posaconazole concentrations were higher in patients with chronic GVHD than in those with acute GVHD. In 18 patients without invasive fungal infection who experienced diarrhea on the day of sampling, posaconazole concentrations were lower than the concentrations in patients without diarrhea. No relationship was observed between alanine aminotransferase, aspartate aminotransferase, or bilirubin levels and posaconazole concentrations.

CONCLUSION

Posaconazole 200 mg 3 times/day resulted in median plasma drug concentrations sufficiently high to prevent invasive fungal infections in HSCT recipients with GVHD, without compromising patient safety. Plasma posaconazole concentrations are generally unaffected by demographic variables, including race, sex, body weight, and age.

Minimizing the risk of recurrent or progressive invasive mold infections during stem cell transplantation or further intensive chemotherapy

The risk of recurrence or progression of prior invasive fungal infection, predominantly due to molds, is 11-33% during subsequent stem cell transplantations or myelosuppressive chemotherapy, with a high mortality. Risk factors at the time of transplant include active infection and having received <6 weeks of antifungal therapy, while after transplant prolonged neutropenia and graft-versus-host disease requiring aggressive immunosuppression are important. The use of peripheral blood stem cells has been associated with a lower risk. Minimal data are available regarding the role of preventative strategies such as surgical resection of pulmonary lesions and prophylactic granulocyte transfusions during neutropenia, the optimal duration of antifungal prophylaxis, and the appropriate monitoring strategy. This article critically evaluates these issues and provides recommendations for the secondary prophylaxis of invasive mold infections.

Will resistance in fungi emerge on a scale similar to that seen in bacteria?

Growing numbers of patients receive azoles as prophylaxis or treatment for invasive fungal infections, begging the question of whether emergence of resistance will occur, as has been seen with bacteria. This review examines resistance pathways shared by bacteria and fungi, including alteration and overproduction of drug targets, changes in biosynthetic pathways, and enhanced drug efflux, and assesses whether such commonalities predict increased resistance to azoles. Important differences exist between the two kingdoms, including little, if any, horizontal transfer of extrachromosomal material across fungal species and a longer fungal generation time, thereby slowing vertical transfer of mutant traits. Further, no enzymatic modulation or inactivation of azoles has been reported in fungi. The newer broad-spectrum azoles posaconazole and voriconazole are active against the vast majority of yeasts and moulds and are likely to prevent the emergence of inherently resistant strains. Therefore, the likelihood for an explosion of fungal resistance is relatively low.

Selection of a surrogate agent (fluconazole or voriconazole) for initial susceptibility testing of posaconazole against Candida spp.: results from a global antifungal surveillance program

There are currently no FDA-approved broth microdilution antifungal susceptibility testing products or interpretive breakpoints for susceptibility testing of the new triazole posaconazole. Fluconazole and voriconazole are in the same triazole class as posaconazole, have CLSI-approved interpretive MIC breakpoints, and are available on some commercially available MIC panels. We investigated whether one or both of these agents may be useful as a surrogate marker for posaconazole susceptibility. Fluconazole, voriconazole, and posaconazole MIC results for 10,807 isolates of Candida spp. were analyzed to validate a potential surrogate marker for posaconazole activity against indicated species. For illustrative purposes, we applied the voriconazole MIC breakpoints to posaconazole (susceptible, < or =1 microg/ml; susceptible dose dependent, 2 microg/ml; resistant, > or =4 microg/ml) and compared these MIC results and categorical interpretations with those of fluconazole and voriconazole by using regression statistics and categorical agreement. For all 10,807 isolates, the absolute categorical agreement was 91.1% (0.1% very major errors [VME], 1.2% major errors [ME], and 7.6% minor errors [M]) using fluconazole as the surrogate marker and 97.7% (0.3% VME 0.1% ME, and 1.9% M) using voriconazole as the surrogate. The results with fluconazole improved to a categorical agreement of 93.7% (0.1% VME, 0.2% ME, and 6.0% M) when results for Candida krusei (not indicated for fluconazole testing) were omitted. Either fluconazole or voriconazole MIC results may serve as surrogate markers to predict the susceptibility of Candida spp. to posaconazole.

Posaconazole: a next-generation triazole antifungal

Posaconazole is a new drug in the triazole class that has recently been investigated in pivotal Phase III clinical trials. Its antifungal activity is based on the inhibition of the fungal ergosterol synthesis. As demonstrated in vitro, posaconazole exhibits fungicidal activity against Aspergillus spp., Candida spp. and zygomycetes. Currently, posaconazole is only available as an oral suspension. Food consumption affects the bioavailability of posaconazole, while the exposure to posaconazole increases in a dose-proportional manner with a saturation of absorption occurring with a daily dose over 800 mg. Posaconazole is well tolerated without an increase in risk of any treatment-related adverse events during prolonged treatment for 6 or more months (n = 108). Posaconazole has been recently approved by the US FDA and other regulatory bodies for the treatment of oropharyngeal candidiasis, and the prophylaxis of invasive Aspergillus and Candida infections in severely immunocompromised patients. As demonstrated in two pivotal Phase III trials, posaconazole prophylaxis of invasive fungal infection in patients severely immunocompromised by graft-versus-host disease (n = 600) or neutropenia (n = 602) is superior to fluconazole and/or itraconazole prophylaxis. Significantly more patients who received posaconazole, instead of fluconazole, as treatment for oropharyngeal candidiasis sustained clinical success after the treatment was stopped. Preliminary data from a subgroup analysis (n = 24) of two salvage therapy trials for invasive fungal infections, as well as single case reports and series and in vitro studies, suggest that posaconazole might be an attractive oral treatment alternative for zygomycosis.

Posaconazole activity against Candida glabrata after exposure to caspofungin or amphotericin B

We evaluated the effects of sequential therapy with caspofungin (CAS) or amphotericin B (AMB) followed by posaconazole (POS) against Candida glabrata. The susceptibilities to POS of yeast cells pre-exposed to CAS or AMB were identical to those of untreated cells as shown by standard Clinical and Laboratory Standards Institute broth dilution, cell viability, and disk diffusion methods. We then investigated the activity of sequential regimens in an experimental model of disseminated candidiasis. CAS given at 1 mg/kg/day for 2 days followed by POS at either 15 or 30 mg/kg/day significantly reduced the counts compared to the controls, but this treatment was not superior to the use of CAS alone. Also, sequential regimens with AMB given at 1 mg/kg/day for 2 days followed by POS (AMB/POS) were effective at reducing the fungal burden against the controls. In addition, AMB/POS with both doses of the triazole were significantly more effective than AMB alone. Overall, our data showed that there is no therapeutic advantage in using CAS followed by POS, whereas an induction therapy with AMB followed by a maintenance regimen with POS might be a suitable strategy in managing C. glabrata infections.

Antifungal Prophylaxis in Cancer Patients After Chemotherapy or Hematopoietic Stem-Cell Transplantation: Systematic Review and Meta-Analysis

Purpose

To evaluate the effect of antifungal prophylaxis on all-cause mortality as primary outcome, invasive fungal infections (IFIs), and adverse events. Many studies have evaluated the role of antifungal prophylaxis in cancer patients, with inconsistent conclusions.

Methods

We performed a systematic review and meta-analysis of randomized, controlled trials comparing systemic antifungals with placebo, no intervention, or other antifungal agents for prophylaxis in cancer patients after chemotherapy. The Cochrane Library, MEDLINE, conference proceedings, and references were searched. Two reviewers independently appraised the quality of trials and extracted data.

Results

Sixty-four trials met inclusion criteria. Antifungal prophylaxis decreased all-cause mortality significantly at end of follow-up compared with placebo, no treatment, or nonsystemic antifungals (relative risk [RR], 0.84; 95% CI, 0.74 to 0.95). In allogeneic hematopoietic stem-cell transplantation (HSCT) recipients, prophylaxis reduced all-cause mortality (RR, 0.62; 95% CI, 0.45 to 0.85), fungal-related mortality, and documented IFI. In acute leukemia patients, there was a significant reduction in fungal-related mortality and documented IFI, whereas the difference in mortality was only borderline significant (RR, 0.88; 95% CI, 0.74 to 1.06). Prophylaxis with itraconazole suspension reduced documented IFI when compared with fluconazole, with no difference in survival, and at the cost of more adverse events. On the basis of two studies, posaconazole prophylaxis reduced all-cause mortality (RR, 0.74; 95% CI, 0.56 to 0.98), fungal-related mortality, and IFI when compared with fluconazole.

Conclusion

Antifungal prophylaxis decreases all-cause mortality significantly in patients after chemotherapy. Antifungal prophylaxis should be administered to patients undergoing allogeneic HSCT, and should probably be administered to high-risk acute leukemia patients.

Economic Evaluation of Posaconazole Versus Standard Azole Prophylaxis in High Risk Neutropenic Patients in The Netherlands

Background: Acute leukemia and high risk myelodysplastic syndrome patients experience prolonged neutropenia after treatment with intensive chemotherapy, leading to a high risk of acquiring potentially fatal invasive fungal infections (IFI). Pharmacoeconomic analysis is considered a valuable tool to justify the significant costs involved in managing these fungal infections. The present study evaluates the cost-effectiveness of posaconazole versus standard azoles for the prevention of IFIs in neutropenic patients in the Netherlands.

Methods: A decision-tree model was developed that starts with the choice of antifungal prophylaxis: posaconazole or standard azole treatment (fluconazole or itraconazole). The decision tree was estimated using data from a recently published prospective, randomized, double blind, multi-center trial that compared both treatments in neutropenic patients receiving remission-induction chemotherapy for AML/MDS (Cornely et al., 2007). Following initiation of prophylaxis, clinical events are modeled with chance nodes reflecting probabilities of IFIs, IFI related death, and death from other causes. It is assumed that patients surviving the prophylactic period will have a life expectancy that reflects that of the underlying condition. This allows translation of the trial outcomes to a lifetime horizon. Data on life expectancy, quality of life, medical resource consumption and costs were obtained from the literature. Model outcomes include incremental cost per IFI avoided, incremental cost per life years saved and incremental cost per QALYs gained.

Results: The total cost (treatment of breakthrough IFI + prophylaxis) for posaconazole amounted to €4,566 (95% uncertainty interval €3,574 –€5,769), which is €63 (−€1,552 - €1,903) less than costs with standard azoles. Posaconazole prophylaxis resulted in 0.1 (0.03 – 0.15) QALYs gained in comparison to prophylaxis with standard azoles. Results from a probabilistic sensitivity analysis indicate that there is a 87% probability that the cost per QALY gained with posaconazole is below €20,000, a commonly accepted threshold for cost-effectiveness. Additional scenario analyses with different assumptions confirmed these findings.

Conclusion: Given the underlying data and assumptions, our economic evaluation demonstrated that posaconazole prophylaxis is cost and QALY saving compared to fluconazole / itraconazole in neutropenic AML/MDS patients after intensive chemotherapy.

Combination antifungals: an update

Invasive fungal infections are an important cause of morbidity and mortality in specific patient populations. There has been an impressive increase in the antifungal armamentarium, yet optimal therapies for many invasive fungal infections remain unknown. Genomic sequencing of a number of pathogenic fungi will pave the way to discovering additional newer targets for antifungal drug design. These new discoveries, plus the existing repertoire of antifungal agents, create the need to effectively model single and combination antifungal agents. Future therapies may also include the use of cell-stress pathway inhibitors in combination with existing antifungal agents. This review focuses on combination antifungal therapy against Cryptococcus neoformans, Candida and Aspergillus species. Combination therapy is only supported by randomized clinical trials for cryptococcal meningitis. We review data from in vitro and animal model studies as well as insights from clinical trials to discuss current thoughts and highlight the gaps in our knowledge surrounding combination antifungal therapy.

A double-blind trial on prophylactic voriconazole (VRC) or placebo during induction chemotherapy for acute myelogenous leukaemia (AML)

OBJECTIVES

Invasive fungal infections remain a frequent cause of morbidity and mortality in long-term neutropenic patients. The availability of tolerable broad-spectrum antifungals like voriconazole stimulated the discussion about optimal timing of antifungal therapy. We conducted a trial to analyze the efficacy and safety of voriconazole in the prevention of lung infiltrates during induction chemotherapy for acute myelogenous leukaemia (AML).

METHODS

This was a prospective, randomised, double-blind, placebo-controlled phase III trial in AML patients undergoing remission induction chemotherapy. Oral voriconazole 200 mg twice daily or placebo was administered until detection of a lung infiltrate or end of neutropenia. Primary efficacy parameter was the incidence of lung infiltrates until day 21 after initiation of chemotherapy. Secondary objectives were incidence of infections, length of stay in hospital, time to antifungal treatment, time to first fever, and drug safety.

RESULTS

A total of 25 patients were randomly assigned to receive voriconazole (N=10) or placebo (N=15). Incidence of lung infiltrates until day 21 was 0 (0%) in the voriconazole and 5 (33%) in the placebo group (P=0.06). Average length of stay in hospital was shorter in the voriconazole group (mean 31.9 days) than in the placebo group (mean 37.3 days, P=0.09). Four patients were diagnosed with hepatosplenic candidiasis until a 4 week follow-up, all in the placebo group (P=0.11). Adverse events and toxicity did not differ between the two treatment groups. The trial was stopped prematurely when another trial demonstrated reduced mortality by antifungal prophylaxis with posaconazole, thus rendering further randomisation against placebo unethical.

CONCLUSION

In AML patients undergoing induction chemotherapy, prophylactic oral voriconazole 200 mg twice daily resulted in trends towards reduced incidences of lung infiltrates and hepatosplenic candidiasis. Voriconazole was safe and well tolerated.

Recent advances and challenges in the treatment of invasive fungal infections

The frequency of invasive fungal infections (IFIs) has increased over the last decade with the rise in at-risk populations of patients. The morbidity and mortality of IFIs are high and management of these conditions is a great challenge. With the widespread adoption of antifungal prophylaxis, the epidemiology of invasive fungal pathogens has changed. Non-albicans Candida, non-fumigatus Aspergillus and moulds other than Aspergillus have become increasingly recognised causes of invasive diseases. These emerging fungi are characterised by resistance or lower susceptibility to standard antifungal agents. Invasive infections due to these previously rare fungi are therefore more difficult to treat. Recently developed antifungal agents provide the potential to improve management options and therapeutic outcomes of these infections. The availability of more potent and less toxic antifungal agents, such as second-generation triazoles and echinocandins, has led to considerable improvement in the treatment of IFIs. This article reviews the changing spectrum of invasive mycosis, the properties of recently developed antifungal agents and their role in the management of these infections.

Invasive aspergillosis: epidemiology, diagnosis and management in immunocompromised patients

Morbidity and mortality caused by invasive Aspergillus infections are increasing. This is because of the higher number of patients with malignancies treated with intensive immunosuppressive therapy regimens as well as their improved survival from formerly fatal bacterial infections, and the rising number of patients undergoing allogeneic haematopoietic stem cell or organ transplantation. Early initiation of effective systemic antifungal treatment is essential for a successful clinical outcome in these patients; however, clinical clues for diagnosis are sparse and early microbiological proof of invasive aspergillosis (IA) is rare. Clinical diagnosis is based on pulmonary CT scan findings and non-culture based diagnostic techniques such as galactomannan or DNA detection in blood or bronchoalveolar lavage samples. Most promising outcomes can be expected in patients at high risk for aspergillosis in whom antifungal treatment has been started pre-emptively, backed up by laboratory and imaging findings. The gold standard of systemic antifungal treatment is voriconazole, which has been proven to be significantly superior to conventional amphotericin B and has led to a profound improvement of survival rates in patients with cerebral aspergillosis. Liposomal amphotericin B at standard dosages appears to be a suitable alternative for primary treatment, while caspofungin, amphotericin B lipid complex or posaconazole have shown partial or complete response in patients who had been refractory to or intolerant of primary antifungal therapy. Combination therapy with two antifungal compounds may be a promising future strategy for first-line treatment. Lung resection helps to prevent fatal haemorrhage in single patients with pulmonary lesions located in close proximity to larger blood vessels, but is primarily considered for reducing the risk of relapse during subsequent periods of severe immunosuppression. Strict reverse isolation appears to reduce the incidence of aspergillosis in allogeneic stem cell transplant recipients and patients with acute myeloid leukaemia undergoing aggressive anticancer therapy. Well designed, prospective randomised studies on infection control measures effective to prevent aspergillosis are lacking. Prophylactic systemic antifungal treatment with posaconazole significantly improves survival and reduces IA in acute myeloid leukaemia patients and reduces aspergillosis incidence rates in patients with intermediate-to-severe graft-versus-host reaction emerging after allogeneic haematopoietic stem cell transplantation. Voriconazole prophylaxis may be suitable for prevention of IA as well; however, the results of large clinical trials are still awaited.

Infectious complication in 314 patients after high-dose therapy and autologous hematopoietic stem cell transplantation: risk factors analysis and outcome

BACKGROUND

Infectious complications occur in most of the patients receiving high-dose therapy (HDT) and autologous hematopoietic stem cell transplantation (HSCT). The objective of the study was to analyze of the type and incidence of infectious complications during neutropenia after HDT and autologous HSCT with respect to risk factors related to stem cell transplant setting in patients treated for hematological malignancies in a single center.

PATIENTS AND METHODS

A total number of 314 patients diagnosed for Hodgkin's disease (HD), non-Hodgkin's lymphoma (NHL), acute myeloid leukemia (AML), multiple myeloma (MM) or acute lymphoblastic leukemia (ALL) were included in the study. Analysis of risk factors and outcome of infections after HDT and autologous HSCT was performed.

RESULTS

Infectious complications during neutropenia after HDT occurred in 92.3% patients. Microbiologically documented infections (MDI) accounted for 38.9% of febrile episodes, clinically documented infections (CDI) for 9.3%, and fever of unknown origin (FUO) for 51.7% cases. Median time to defervescence with antibiotic therapy was seven days for FUO and nine days for documented infections (p < 0.001). Duration of infection correlated with the length of very severe neutropenia (p < 0.001). Response to first-line antibiotic therapy was seen in 34% patients. Infections were fatal in 12 (3.8%) patients. The highest probability of infection was observed for ALL and AML patients, especially these conditioned with total body irradiation (TBI).

CONCLUSION

Patients at high risk of infection after autologous HSCT were identified as those with acute leukemia and those after conditioning with TBI, all with prolonged neutropenia. We suggest that newer prophylactic strategies should be administered to these groups of patients.

Estado actual del diagnóstico precoz de las infecciones invasoras causadas por Aspergillus y otros hongos filamentosos emergentes

The usefulness of surrogate markers in the diagnosis of invasive fungal infections caused by Aspergillus and other emerging mycelial fungi is based on the ability of surrogate markers to detect the infection caused by different species of mycelial fungi. Conventional microbiological methods for diagnosis of fungal disease are slow and insensitive. Antigen based assays or measurement of (1-3)-beta-D-glucan in blood have been developed and validated in clinical laboratories. We review these diagnostic contemporary tools, their clinical application and impact.

Safety, Tolerance, and Efficacy of Posaconazole Therapy in Patients with Nonmeningeal Disseminated or Chronic Pulmonary Coccidioidomycosis

BACKGROUND

Coccidioidomycosis can be difficult to treat with available therapies, particularly in patients with progressive or disseminated disease. Posaconazole is a new azole antifungal with potent activity against Coccidioides species, the causative agent of coccidioidomycosis.

METHODS

Twenty patients with chronic pulmonary or nonmeningeal disseminated coccidioidomycosis were enrolled in a multicenter trial to study the safety and tolerability of posaconazole therapy, with efficacy as a secondary end point. Patients received posaconazole (400 mg/day) in capsule formulation for up to 6 months. Safety was evaluated on the basis of the occurrence of adverse events. A satisfactory efficacy response was defined as a >or=50% reduction in the Mycoses Study Group score from baseline.

RESULTS

Seventeen (85%) of 20 patients had a satisfactory response to treatment. The median duration of treatment was 173 days. Paired baseline and end-of-treatment culture results for Coccidioides species were available for 4 patients, all of whom converted from being positive to being negative for Coccidioides species. Relapse was experienced by 3 of 9 patients who did not receive antifungal therapy during the follow-up period. In general, posaconazole therapy was well tolerated, with 12 of 20 patients reporting adverse events that were possibly or probably related to treatment. The most common adverse events were dry mouth (in 5 patients [25%]) and headache (in 3 patients [15%]).

CONCLUSIONS

Courses of posaconazole therapy that were up to 6 months in duration were well tolerated in patients with coccidioidomycosis. Although this study was limited by the number of patients enrolled, it clearly demonstrates that posaconazole shows promise in the treatment of patients with coccidioidomycosis and warrants additional investigation in a full-scale clinical trial.

Improved outcomes associated with advances in therapy for invasive fungal infections in immunocompromised hosts

Invasive fungal infections cause substantial morbidity and mortality in immunocompromised hosts. The response rate to therapy, in particular for invasive aspergillosis and invasive mould infections, has been poor. Recently a number of techniques to facilitate early diagnosis of these infections, in parallel with the development of a number of antifungals with increased potency and lower toxicity, have raised optimism that outcomes for invasive fungal infection can be improved upon. The availability of lipid formulations of amphotericin B, azoles with extended spectrum against filamentous fungi and the development of a new class of antifungal agents, the echinocandins, presents the clinician with a range of therapeutic choices. Recent clinical trials have provided important insights into how these agents should be used. In particular, voriconazole has demonstrated superior efficacy to amphotericin B in the management of invasive aspergillosis, posaconazole has been shown to have significant efficacy in the prophylaxis of invasive fungal infection in high-risk individuals and a role in salvage therapy of invasive aspergillosis, caspofungin has demonstrated efficacy in salvage therapy of invasive aspergillosis, and each of the echinocandins show activity without significant toxicity in invasive candidiasis. Nevertheless, many therapeutic areas of uncertainty remain, including the role of combination therapy, and will provide the focus for future studies.

Breakthrough infection of Trichosporon asahii during posaconazole treatment in a patient with acute myeloid leukaemia

A neutropenic patient with acute myeloid leukaemia experienced a breakthrough infection of Trichosporon asahii during posaconazole treatment. After treatment was changed to a combination therapy with voriconazole and liposomal amphotericin B, the infection resolved. Posaconazole works effectively as an antifungal prophylaxis and salvage therapy in rare invasive fungal infections. This case however illustrates that breakthrough infections with T. asahii may occur during posaconazole treatment.