Antifungal prophylaxis with itraconazole in neutropenic patients with acute leukaemia

Risk stratification system for skin and soft tissue infections after allogeneic hematopoietic stem cell transplantation: PAH risk score

Skin and soft tissue infections (SSTIs) refer to infections involving the skin, subcutaneous tissue, fascia, and muscle. In transplant populations with hematological malignancies, an immunocompromised status and the routine use of immunosuppressants increase the risk of SSTIs greatly. However, to date, the profiles and clinical outcomes of SSTIs in hematopoietic stem cell transplantation (HSCT) patients remain unclear. This study included 228 patients (3.67%) who developed SSTIs within 180 days after allogeneic HSCT from January 2004 to December 2019 in Peking University People's Hospital. The overall annual survival rate was 71.5%. We compared the differences between survivors and non-survivors a year after transplant and found that primary platelet graft failure (PPGF), comorbidities of acute kidney injury (AKI), and hospital-acquired pneumonia (HAP) were independent risk factors for death in the study population. A PPGF-AKI-HAP risk stratification system was established with a mortality risk score of 1×PPGF+1×AKI+1×HAP. The areas under the curves of internal and external validation were 0.833 (95% CI 0.760-0.906) and 0.826 (95% CI 0.715-0.937), respectively. The calibration plot revealed the high consistency of the estimated risks, and decision curve analysis showed considerable net benefits for patients.

Trough concentration of itraconazole and its relationship with efficacy and safety: a systematic review and meta-analysis

Objectives

The optimum trough concentration of itraconazole for clinical response and safty is controversial. The objective of this systematic review and meta-analysis was to determine the optimum trough concentration of itraconazole and evaluate its relationship with efficacy and safety.

Methods

We searched PubMed, EMBASE, Web of Science, the Cochrane Library, Clinical-Trials.gov, and three Chinese literature databases (CNKI, WanFang, and CBM). We included observational studies that compared clinical outcomes below or above the trough concentration cut-off value which we set as 0.25, 0.5, and 1.0 mg/L. The efficacy outcomes were rate of successful treatment, rate of prophylaxis failure and invasive fungal infection (IFI)-related mortality. The safety outcomes included incidents of hepatotoxicity and other adverse events.

Results

The study included a total of 29 studies involving 2,346 patients. Our meta-analysis showed that compared with itraconazole trough concentrations (C_trough) of ≥0.25 mg/L, levels of <0.25 mg/L significantly increased the incidence of IFI for prophylaxis (RR =3.279, 95% confidence interval [CI] 1.73–6.206). Moreover, the success rate of treatment decreased significantly at a cut-off level of 0.5 mg/L (RR =0.396, 95% CI 0.176–0.889). An itraconazole trough level of 1.0 mg/L was associated with hepatotoxicity and other adverse events in a review of many studies.

Conclusion

An itraconazole trough concentration of 0.25 mg/L should be considered as the lower threshold for prophylaxis, and a target concentration of 0.5 mg/L should be the lower limit for effective treatment. A trough level of 1.0 mg/L is associated with increased hepatotoxicity and other adverse events (using High Performance Liquid Chromatography [HPLC]).

Infectious diseases in allogeneic haematopoietic stem cell transplantation: prevention and prophylaxis strategy guidelines 2016

Infectious complications after allogeneic haematopoietic stem cell transplantation (allo-HCT) remain a clinical challenge. This is a guideline provided by the AGIHO (Infectious Diseases Working Group) of the DGHO (German Society for Hematology and Medical Oncology). A core group of experts prepared a preliminary guideline, which was discussed, reviewed, and approved by the entire working group. The guideline provides clinical recommendations for the preventive management including prophylactic treatment of viral, bacterial, parasitic, and fungal diseases. The guideline focuses on antimicrobial agents but includes recommendations on the use of vaccinations. This is the updated version of the AGHIO guideline in the field of allogeneic haematopoietic stem cell transplantation utilizing methods according to evidence-based medicine criteria.

A reference laboratory experience of clinically achievable voriconazole, posaconazole, and itraconazole concentrations within the bloodstream and cerebral spinal fluid

Interest in antifungal therapeutic-drug monitoring has increased due to studies demonstrating associations between concentrations and outcomes. We reviewed the antifungal drug concentration database at our institution to gain a better understanding of achievable triazole drug levels. Antifungal concentrations were measured by high-performance liquid chromatography (HPLC), ultraperformance liquid chromatography and single-quadrupole mass spectrometry (UPLC/MS), or a bioassay. For this study, only confirmed human bloodstream (serum or plasma) and cerebral spinal fluid (CSF) concentrations of voriconazole, posaconazole, and itraconazole were analyzed. The largest numbers of bloodstream and CSF samples were found for voriconazole (14,370 and 173, respectively). Voriconazole bloodstream concentrations within the range of 1 to 5.5 μg/ml represented 50.6% of samples. Levels below the lower limit of quantification (0.2 μg/ml) were observed in 14.6% of samples, and 10.4% of samples had levels of ≥5.5 μg/ml. CSF voriconazole levels ranged from undetectable to 15.3 μg/ml and were <0.2 μg/ml in 11% of samples. Posaconazole bloodstream concentrations were ≥0.7 and ≥1.25 μg/ml in 41.6% and 18.9% of samples, respectively. Posaconazole was detected in only 4 of 22 CSF samples (undetectable to 0.56 μg/ml). Itraconazole levels, as measured by UPLC/MS, were ≥0.5 μg/ml in 43.3% and were undetectable in 33.9% of bloodstream samples. In contrast, when measured by a bioassay, itraconazole/hydroxyitraconazole bloodstream concentrations were ≥1.0 μg/ml in 72.9% of samples and were undetectable in 18% of samples. These results indicate that there is marked variability in bloodstream concentrations achieved with these three azoles. In addition, many levels within the bloodstream for each azole and for voriconazole and posaconazole in the CSF were undetectable or below thresholds associated with efficacy.

Soluble itraconazole in tablet form using disordered drug delivery approach: critical scale-up considerations and bio-equivalence studies

The present research work explores formulation design, critical scale-up considerations and bio-equivalence studies of soluble itraconazole (ITZ) in a tablet form using disordered drug delivery approach. Disordered system of ITZ with a lower viscosity grade of hydroxypropyl methyl cellulose (Pharmacoat 603) was developed for the first time and extensively characterised at three different stages, namely development of glass system, pellet coating and tablet compression using advanced analytical techniques. Complete molecular embedment of ITZ resulting in amorphisation was observed and found to be sustained until end of the real-time and accelerated stability studies. Developed formulation exhibited comparative in vitro dissolution profile (similarity factor>70) with reference product (Sporanox, Janssen Pharmaceutica) in simulated gastric fluid without enzymes. Formulation was scaled up in three batches (50,000 tablets/batch) with detailed validation of critical process parameters using process capability index method. Critical scale-up considerations like control of residual solvent content, effect of pellet size on dissolution, process variables in pellet coating, compressibility of coated pellets and cushioning effect required for desired compressibility were thoroughly discussed. Bioequivalence study of single dose of test and reference product in seven healthy human volunteers under fed condition exhibited significant bioequivalence with results (AUClast and AUC∞) lying between 90% confidence interval. With increase in number of subjects to 24, a significant effect on pharmacokinetic parameters of both reference as well as developed ITZ tablets was observed.

Primary prophylaxis of invasive fungal infections in patients with hematologic malignancies. Recommendations of the Infectious Diseases Working Party of the German Society for Haematology and Oncology

There is no widely accepted standard for antifungal prophylaxis in patients with hematologic malignancies. The Infectious Diseases Working Party of the German Society for Haematology and Oncology assigned a committee of hematologists and infectious disease specialists to develop recommendations. Literature data bases were systematically searched for clinical trials on antifungal prophylaxis. The studies identified were shared within the committee. Data were extracted by two of the authors (OAC and MSi). The consensus process was conducted by email communication. Finally, a review committee discussed the proposed recommendations. After consensus was established the recommendations were finalized. A total of 86 trials were identified including 16,922 patients. Only a few trials yielded significant differences in efficacy. Fluconazole 400 mg/d improved the incidence rates of invasive fungal infections and attributable mortality in allogeneic stem cell recipients. Posaconazole 600 mg/d reduced the incidence of IFI and attributable mortality in allogeneic stem cell recipients with severe graft versus host disease, and in patients with acute myelogenous leukemia or myelodysplastic syndrome additionally reduced overall mortality. Aerosolized liposomal amphotericin B reduced the incidence rate of invasive pulmonary aspergillosis. Posaconazole 600 mg/d is recommended in patients with acute myelogenous leukemia/myelodysplastic syndrome or undergoing allogeneic stem cell recipients with graft versus host disease for the prevention of invasive fungal infections and attributable mortality (Level A I). Fluconazole 400 mg/d is recommended in allogeneic stem cell recipients until development of graft versus host disease only (Level A I). Aerosolized liposomal amphotericin B is recommended during prolonged neutropenia (Level B II).

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.

Antifungal prophylaxis for invasive mycoses in high risk patients

PURPOSE OF REVIEW

New broader spectrum antifungal agents with favorable safety profiles have been available for the last 15 years making prophylaxis feasible. The purpose of this article is to review recent studies in patient populations at high risk for invasive fungal infections.

RECENT FINDINGS

Itraconazole, lipid formulations of amphotericin B, posaconazole, caspofungin and micafungin have been utilized for prophylaxis in different immunocompromised host settings. Itraconazole and caspofungin remain an option especially in patients with hematological diseases. Low dose liposomal amphotericin B shows a lower morbidity rate in patients treated for acute myeloid leukemia. Posaconazole demonstrated survival benefits in this setting although data have only been presented at an international meeting. In the transplantation setting, micafungin was superior to fluconazole during the early neutropenic phase and posaconazole was superior to fluconazole in preventing invasive aspergillosis in hematopoietic transplant recipients treated for graft-versus-host disease. Results from the latter study have thus far only been presented in abstract form.

SUMMARY

Prophylaxis should only be given to a high-risk population. Results of studies should demonstrate morbidity and mortality advantages. The new generation of azoles and echinocandins have a favorable safety and drug interaction profile and appear advantageous in specific settings of immunosuppression. Pending full publication, posaconazole appears to be an appropriate agent for prophylaxis in acute myeloid leukemia patients or patients treated for graft-versus-host disease. Micafungin is superior to fluconazole in the neutropenic phase of hematopoietic transplantation.

Itraconazole prophylaxis in pediatric cancer patients receiving conventional chemotherapy or autologous stem cell transplants

GOAL OF WORK

During the renovation works at our institution, the incidence density for invasive aspergillosis (IA) increased from <0.5 to 0.99/1,000 inpatient days in 2001. As a direct response to this increased environmental risk, itraconazole (ITC) was administered for primary prophylaxis in pediatric cancer patients for whom a particular high risk of IA was anticipated due to prolonged severe neutropenia (>10 days), autologous stem cell transplantation, acute myeloblastic leukemia or relapsed acute lymphoblastic leukemia, or high-dose steroids >3 weeks.

MATERIALS AND METHODS

In this open-label, prospective observational study, ITC was given in ITC solution or capsule. Trough concentrations were measured in plasma with high-performance liquid chromatography after at least 7 days of treatment. Doses were adjusted to target plasma trough ITC concentrations > or =0.5 mg/l.

RESULTS

From 2001 to 2005, 39 pediatric cancer patients received 44 prophylactic ITC cycles; 102 trough plasma concentrations were measured after oral administration. Plasma target concentrations >0.5 mg/l were achieved with both formulations. A median dose of 8 mg kg(-1) day(-1) (3.5-16.0 mg kg(-1) day(-1)) was necessary in pediatric oncology patients. The bioavailability of the liquid formulation was significantly lower when the solution was given by a feeding tube. Adverse effects (gastrointestinal, elevated transaminases, and one hemolysis) which led to the cessation of the ITC prophylaxis were reported in 11% of all courses. No breakthrough infection was seen in this pediatric population.

CONCLUSION

Oral ITC offers a feasible and inexpensive option for antifungal prophylaxis in selected pediatric cancer patients. Drug monitoring and meticulous consideration of possible interactions and adverse effects are mandatory.

Antimicrobial prophylaxis in allogeneic bone marrow transplantation. Guidelines of the Infectious Diseases Working Party (AGIHO) of the German Society of Haematology and Oncology

Patients undergoing allogeneic stem cell transplantation are at high risk for infection with a variety of pathogens during different phases of the procedure. Bacteria and fungi predominate the first phase until engraftment. During the second phase, from engraftment to about day 100, major infectious problems are caused by fungi and cytomegalovirus. Both pathogens remain important under continued immunosuppression, however, in the late post-transplantation period infections with encapsulated bacteria may become a problem. In this review the Infectious Diseases Working Party of the DGHO gives recommendations for prophylaxis of infections under allogeneic stem cell transplantation with drugs and other measures. The aim of the group was to do this on an evidence-based-medicine rating, if possible.

Choices aplenty: antifungal prophylaxis in hematopoietic stem cell transplant recipients

The incidence of invasive fungal infection (IFIs) in hematopoietic stem cell transplantation (HSCT) recipients ranges from 10 to 25% with an overall case fatality rate of up to 70-90%. Candida and Aspergillus genera remain the two most common pathogens. Although fluconazole prophylaxis in this population has been moderately effective in reducing mortality due to invasive candidiasis, this agent does not have activity against invasive aspergillosis (IA) and other mould. Several new agents such as voriconazole and caspofungin have enhanced potency and broad-spectrum antifungal activity and show promising results against yeasts and filamentous fungi when given as therapy and as chemoprophylaxis. Further, new diagnostic tools to detect circulating fungal antigens in biological fluids and PCR-based methods to detect species or genus-specific DNA or RNA have been developed. Incorporating these techniques along with clinical criteria appear to improve the accuracy of preclinical diagnosis of IFIs. Such approaches may alter the current treatment strategy from prophylaxis to pre-emptive therapy, thereby potentially decreasing cost and toxicity in high-risk patients.

Amphotericin B lipid complex as prophylaxis of invasive fungal infections in patients with acute myelogenous leukemia and myelodysplastic syndrome undergoing induction chemotherapy

BACKGROUND

The optimal antifungal prophylactic regimen for patients with acute myelogenous leukemia (AML) or high-risk myelodysplastic syndrome (MDS) undergoing induction chemotherapy has yet to be identified. A prospective historical control study evaluated the efficacy and safety of amphotericin B lipid complex (ABLC) in this patient population.

METHODS

Newly diagnosed patients with AML or high-risk MDS who were undergoing induction chemotherapy received prophylactic ABLC 2.5 mg/kg intravenously 3 times weekly. This treatment group was compared with a historical control group that had similar baseline characteristics and received prophylactic liposomal amphotericin B (L-AmB) 3 mg/kg 3 times weekly. The primary endpoint was the incidence of documented or suspected fungal infections during and up to 4 weeks after cessation of prophylaxis. Reported adverse events were used to assess tolerability.

RESULTS

The overall efficacy of antifungal prophylaxis was similar in patients who received ABLC and patients who received L-AmB (P=0.95). Among 131 ABLC-treated patients and 70 L-AmB-treated patients who were assessed for efficacy and safety, 49% of patients in each group completed therapy without developing a documented or suspected fungal infection. Documented fungal infections occurred in 5% of ABLC-treated patients and in 4% of L-AmB-treated patients. Alternative antifungal strategies were required because of persistent fever or pneumonia of unknown pathogen in 28% and 32% of ABLC-treated and L-AmB-treated patients, respectively. Grade 3 and 4 adverse events, therapy discontinuations due to adverse events, and survival rates also were similar between treatment groups.

CONCLUSIONS

ABLC and L-AmB appeared to have similar efficacy and were tolerated well as antifungal prophylaxis in patients with AML and high-risk MDS who were undergoing induction chemotherapy.

Itraconazole--perspectives for the management of invasive aspergillosis

Itraconazole has become an important option in the management of invasive aspergillosis. The compound has potent and broad spectrum antifungal activity in vitro against Aspergillus spp. with a species- and strain dependent fungicidal mode of action. In vivo, the antifungal efficacy of itraconazole has been demonstrated in several non-immunocompromised and immunocompromised animal models of disseminated and invasive pulmonary aspergillosis. Itraconazole is available in oral and intravenous formulations, displays non-linear plasma pharmacokinetics, and is usually well tolerated. Non-comparative clinical data of itraconazole for therapy of suspected or proven invasive aspergillosis suggest response rates similar to those of conventional amphotericin B; however, the experience with itraconazole for induction therapy of invasive aspergillosis is limited, particularly in profoundly neutropenic patients. Itraconazole has an important role for consolidation and maintenance therapy of patients with invasive aspergillosis, and novel combination therapies involving itraconazole are currently under intensive preclinical investigation as to their usefulness for primary therapy.

Evidence-based assessment of primary antifungal prophylaxis in patients with hematologic malignancies

Invasive fungal infection is an increasing source of morbidity and mortality in patients with hematologic malignancies, particularly those with prolonged and severe neutropenia (absolute white blood cell count < 100/microL). Early diagnosis of invasive fungal infection is difficult, suggesting that antifungal prophylaxis could be the best approach for neutropenic patients undergoing intensive myelosuppressive chemotherapy. Consequently, antifungal prophylaxis has been extensively studied for more than 20 years. Nonabsorbable polyenes reduce superficial mycoses but are not effective in preventing or treating invasive fungal infections. Intravenous amphotericin B and the newer azoles were used in numerous clinical trials, but the value of antifungal prophylaxis in defined risk groups with cancer is still open to discussion. Recipients of allogeneic stem cell transplants and patients with a relapsed leukemia are high-risk patient populations. In addition, certain risk factors are well defined, for example, neutropenia more than 10 days, corticosteroid therapy, sustained immunosuppression, and graft-versus-host disease. In contrast to study efforts, evidence-based recommendations on the clinical use of antifungal prophylaxis according to risk groups are rare. The objective of this review of 50 studies accumulating more than 9000 patients is to assess evidence-based criteria with regard to the efficacy of antifungal prophylaxis in neutropenic cancer patients.

Liposomal amphotericin B versus the combination of fluconazole and itraconazole as prophylaxis for invasive fungal infections during induction chemotherapy for patients with acute myelogenous leukemia and myelodysplastic syndrome

BACKGROUND

Fungal infections are a major cause of morbidity and mortality in patients undergoing induction chemotherapy for acute myelogenous leukemia (AML) and myelodysplastic syndrome (MDS). The authors evaluated the efficacy and toxicity of liposomal amphotericin B (L-AmB) compared with a combination of fluconazole plus itraconazole (F+I) as prophylaxis in this setting.

METHODS

Patients with newly diagnosed AML or high-risk MDS who were undergoing initial induction chemotherapy were randomized to receive either F+I (fluconazole 200 mg orally every 12 hours plus itraconazole tablets 200 mg orally every 12 hours) or L-AmB (3 mg/kg intravenously 3 times per week) in this prospective, open-label study.

RESULTS

Seventy-two L-AmB-treated patients and 67 F+I-treated patients were enrolled in the study. Of these, 47% of patients completed antifungal prophylaxis without a change in therapy for proven or suspected fungal infection. Three patients in each arm developed a proven fungal infection. Twenty-three percent of the L-AmB-treated patients and 24% of the F+I-treated patients were changed to alternative antifungal therapy because of persistent fever (P value not significant). Nine percent of the L-AmB-treated patients developed pneumonia of unknown etiology compared with 16% of the F+I-treated patients (P value not significant). Increases in serum creatinine levels to > 2 mg/dL (20% for the L-AmB arm vs. 6% for the F+I arm; P = 0.012) and increases in serum bilirubin levels to > 2 mg/dL (43% vs. 22%, respectively; P = 0.021) were more common with L-AmB. Infusion-related reactions were noted in five L-AmB-treated patients. Responses to chemotherapy and induction mortality rates were similar for the two arms.

CONCLUSIONS

L-AmB and F+I appear similar in their efficacy as antifungal prophylaxis during induction chemotherapy for patients with AML and MDS. L-AmB was associated with higher rates of increased serum bilirubin and creatinine levels.

Fungal infections in nontransplant patients with hematologic malignancies

Fungal infections are a major cause of morbidity and mortality in patients with hematologic malignancies. Candida and Aspergillus species are the most important opportunistic fungal pathogens in this patient population. Dimorphic fungi can cause serious infection in immunocompetent persons, but infection is more likely to be disseminated in patients with compromised cell-mediated immunity. Cryptococcus neoformans and Pneumosystis carinii typically cause infections in persons with severe T-cell suppression. The frequency of rare pathogenic fungi commonly resistant to amphotericin B has significantly increased over the past 20 years among patients with hematologic malignancies. Examples of such emerging pathogens include Trichosporon, Fusarium, and Scedosporium species, and dark-walled molds. This article reviews the epidemiology, clinical manifestations, diagnostic evaluation, and treatment of the major fungal pathogens in nontransplant patients with hematologic malignancies.

Itraconazole preexposure attenuates the efficacy of subsequent amphotericin B therapy in a murine model of acute invasive pulmonary aspergillosis

Antagonism has been described in vitro and in vivo for azole-polyene combinations against Aspergillus species. Using an established murine model of invasive pulmonary aspergillosis, we evaluated the efficacy of several amphotericin B (AMB) dosages given alone or following preexposure to itraconazole (ITC). Mice were immunosuppressed with cortisone acetate and cyclophosphamide. During immunosuppression, animals were administered either ITC solution (50 mg/kg of body weight) or saline by oral gavage twice daily for 3 days prior to infection. Infection was induced by intranasally inoculating mice with a standardized conidial suspension (1 x 10(8) CFU/ml) of Aspergillus fumigatus strain AF 293. AMB was then administered by daily intraperitoneal injections (0.25, 0.5, 1.0, and 3.0 mg/kg) starting 24 h after inoculation and continuing for a total of 72 h. Drug pharmacokinetics of AMB and ITC in plasma were determined by high-performance liquid chromatography. Four different endpoints were used to examine the efficacy of antifungal therapy: (i) viable counts from harvested lung tissue (in CFU per milliliter), (ii) the whole-lung chitin assay, (iii) mortality at 96 h, and (iv) histopathology of representative lung sections. At AMB doses of >0.5 mg/kg/day, fewer ITC-preexposed mice versus non-ITC-preexposed mice were alive at 96 h (0 to 20 versus 60%, respectively). At all time points, the fungal lung burden was consistently and significantly higher in animals preexposed to ITC, as measured by the CFU counts (P = 0.001) and the chitin assay (P = 0.03). Higher doses of AMB did not overcome this antagonism. ITC preexposure was associated with poorer mycological efficacy and survival in mice treated subsequently with AMB for invasive pulmonary aspergillosis.

Antifungal prophylaxis for severely neutropenic chemotherapy recipients: a meta analysis of randomized-controlled clinical trials

BACKGROUND

The overall clinical efficacy of the azoles antifungal agents and low-dose intravenous amphotericin B for antifungal chemoprophylaxis in patients with malignant disease who have severe neutropenia remains unclear.

METHODS

Randomized-controlled trials of azoles (fluconazole, itraconazole, ketoconazole, and miconazole) or intravenous amphotericin B formulations compared with placebo/no treatment or polyene-based controls in severely neutropenic chemotherapy recipients were evaluated using meta-analytical techniques.

RESULTS

Thirty-eight trials that included 7014 patients (study agents, 3515 patients; control patients, 3499 patients) were analyzed. Overall, there were reductions in the use of parenteral antifungal therapy (prophylaxis success: odds ratio [OR], 0.57; 95% confidence interval [95% CI], 0.48-0.68; relative risk reduction [RRR], 19%; number requiring treatment for this outcome [NNT], 10 patients), superficial fungal infection (OR, 0.29; 95% CI, 0.20-0.43; RRR, 61%; NNT, 12 patients), invasive fungal infection (OR, 0.44; 95% CI, 0.35-0.55; RRR, 56%; NNT, 22 patients), and fungal infection-related mortality (OR, 0.58; 95% CI, 0.41-0.82; RRR, 47%; NNT, 52 patients). Invasive aspergillosis was unaffected (OR, 1.03; 95% CI, 0.62-1.44). Although overall mortality was not reduced (OR, 0.87; 95% CI, 0.74-1.03), subgroup analyses showed reduced mortality in studies of patients who had prolonged neutropenia (OR, 0.72; 95% CI, 0.55-0.95) or who underwent hematopoietic stem cell transplantation (HSCT) (OR, 0.77; 95% CI, 0.59-0.99). The multivariate metaregression analyses identified HSCT, prolonged neutropenia, acute leukemia with prolonged neutropenia, and higher azole dose as predictors of treatment effect.

CONCLUSIONS

Antifungal prophylaxis reduced morbidity, as evidenced by reductions in the use of parenteral antifungal therapy, superficial fungal infection, and invasive fungal infection, as well as reducing fungal infection-related mortality. These effects were most pronounced in patients with malignant disease who had prolonged neutropenia and HSCT recipients.

Clinical experience with itraconazole in systemic fungal infections

The broad spectrum antifungal itraconazole is an effective and well tolerated agent for the prophylaxis and treatment of systemic fungal infections. The recent development of an itraconazole oral solution and an intravenous itraconazole solution has increased the options for the use of this drug and increased the oral bioavailability in a variety of at-risk patients. Reliable absorption of the itraconazole oral solution has been demonstrated in patients with HIV infection, neutropenic patients with haematological malignancy, bone marrow transplant recipients and neutropenic children. In clinical trials, itraconazole oral solution (5 mg/kg/day) was more effective at preventing systemic fungal infection in patients with haematological malignancy than placebo, fluconazole suspension (100 mg/day) or oral amphotericin-B (2 g/kg/day) and was highly effective at preventing fungal infections in liver transplant recipients. There were no unexpected adverse events with the itraconazole oral solution in any of these trials. In addition, intravenous itraconazole solution is at least as effective as intravenous amphotericin-B in the empirical treatment of neutropenic patients with systemic fungal infections, and drug-related adverse events are more frequent in patients treated with amphotericin-B. A large proportion of patients with confirmed aspergillosis also respond to treatment with intravenous itraconazole followed by oral itraconazole. The new formulations of itraconazole are therefore effective agents for prophylaxis and treatment of most systemic fungal infections in patients with haematological malignancy.

Current management of fungal infections

The management of superficial fungal infections differs significantly from the management of systemic fungal infections. Most superficial infections are treated with topical antifungal agents, the choice of agent being determined by the site and extent of the infection and by the causative organism, which is usually readily identifiable. One exception is onychomycosis, which usually requires treatment with systemically available antifungals; the accumulation of terbinafine and itraconazole in keratinous tissues makes them ideal agents for the treatment of onychomycosis. Oral candidiasis in immunocompromised patients also requires systemic treatment; oral fluconazole and itraconazole oral solution are highly effective in this setting. Systemic fungal infections are difficult to diagnose and are usually managed with prophylaxis or empirical therapy. Fluconazole and itraconazole are widely used in chemoprophylaxis because of their favourable oral bioavailability and safety profiles. In empirical therapy, lipid-associated formulations of amphotericin-B and intravenous itraconazole are safer than, and at least as effective as, conventional amphotericin-B (the former gold standard). The high acquisition costs of the lipid-associated formulations of amphotericin-B have limited their use.

Fungal infections in patients with neutropenia: challenges in prophylaxis and treatment

Fungal infections are a leading cause of mortality in patients with neutropenia. Candidiasis and aspergillosis account for most invasive fungal infections. General prophylactic measures include strict hygiene and environmental measures. Haemopoietic growth factors shorten the duration of neutropenia and thus may reduce the incidence of fungal infections. Fluconazole is appropriate for antifungal prophylaxis and should be offered to patients with prolonged neutropenia, such as high-risk patients with leukaemia undergoing remission induction or consolidation therapy and high-risk stem cell transplant recipients. Empirical antifungal therapy is mandatory in patients with persistent febrile neutropenia who fail to respond to broad-spectrum antibacterials. Intravenous amphotericin B at a daily dose of 0.6 to 1 mg/kg is preferred whenever aspergillosis cannot be ruled out. Lipid formulations of amphotericin B have demonstrated similar efficacy and are much better tolerated. Fluconazole is the best choice for acute candidiasis in stable patients; amphotericin B should be used in patients with unstable disease. Use of fluconazole is restricted by the existence of resistant strains (Candida krusei and, to a lesser extent, C. glabrata). Amphotericin B still remains the gold standard for invasive aspergillosis. Lipid formulations of amphotericin B are effective in aspergillosis and because they are less nephrotoxic are indicated in patients with poor renal function. Itraconazole is an alternative in patients who have good intestinal function and are able to eat. Mucormycosis, trichosporonosis, fusariosis and cryptococcosis are less common but require specific management. New antifungal agents, especially new azoles, are under development. Their broad in vitro spectrum and preliminary clinical results are promising.

Antifungal pharmacodynamics: review of the literature and clinical applications

Invasive fungal infections are seen with growing frequency, likely due to increases in numbers of patients at risk of infection. Optimal selection and dosing of antifungal agents are important, as these infections are often refractory to available therapy. In contrast to antibacterials, studies examining the pharmacodynamic properties of antifungals and their application in treating invasive disease often are lacking. Agents administered for invasive infections are amphotericin B, flucytosine, and azole antifungals. Several drugs are under investigation, such as posiconazole, voriconazole, and the echinocandins, and preliminary pharmacodynamic data likely will help shape dosing regimens. Clinical trials that investigated dosage and administration, as well as the potential benefits of combination and sequential therapy, are addressed. In addition, antifungal susceptibility and animal models of infection are discussed.

Activities of an intravenous formulation of itraconazole in experimental disseminated Aspergillus, Candida, and Cryptococcus infections

An intravenous (i.v.) formulation of itraconazole was evaluated in disseminated fungal infection models in guinea pigs. In acute disseminated Candida albicans and Aspergillus fumigatus infections, treatment at 5 mg/kg of body weight twice a day (b.i.d.) significantly prolonged survival. In these models and in animals with chronic disseminated cryptococcosis, itraconazole given i.v. at 2.5 and 5 mg/kg b.i.d. greatly reduced the proportions of organs with culture-detectable fungal burdens. The efficacy of i.v. itraconazole in these animal models justifies its further investigation for the treatment of life-threatening mycoses in humans.

Cluster of pulmonary infections caused by Cunninghamella bertholletiae in immunocompromised patients

Cunninghamella bertholletiae is a rare cause of pulmonary mucormycosis. We describe a cluster of invasive pulmonary infections caused by C. bertholletiae in 4 immunocompromised patients that occurred during a 2-year period at 1 center. Three of the patients were receiving antifungal prophylaxis with itraconazole. Presenting symptoms were fever unresponsive to antibacterial chemotherapy, hemoptysis, and infiltrates on chest radiograms. Three patients were treated with liposomal amphotericin B. Only 1 patient survived.

A strategy for managing fungal infections in haematopoietic stem cell transplantation

As more indications continue to be found for allogeneic haematopoietic transplantation, more patients are at risk for invasive fungal infectious diseases (IFID), particularly candidiasis and aspergillosis. Risk factors for disease are becoming better defined and diagnostic methods have improved considerably. In addition, there is now international agreement that three elements form the basis for defining IFID (host factors, clinical evidence, and mycological results), that imaging is acceptable for diagnosing disease, and that indirect tests such as antigen detection are also adequate mycological proof of cause. There are also more drugs available and still more to come, offering the potential for selective prophylaxis as well as preemptive and specific therapy, as well as for flexible administration. Hence, all the elements are in place for designing and testing an effective and economically sound strategy for dealing with IFID.

Itraconazole trough concentrations in antifungal prophylaxis with six different dosing regimens using hydroxypropyl-beta-cyclodextrin oral solution or coated-pellet capsules

We have previously shown that a trough concentration of at least 500 ng ml-1 itraconazole is necessary for an effective antifungal prophylaxis in neutropenic patients. Since the bioavailability of itraconazole is reduced in these patients, a satisfactory dosing regimen remains to be defined. In this study, six dosing regimens with itraconazole capsules 400, 600 or 800 mg day-1, itraconazole solution 400 mg day-1 (additional loading dose: 400 mg day-1 solution for 2 days), 800 mg day-1 or 400 mg day-1 (additional loading dose: 800 mg day-1 capsules for 7 days, s/c1200) were compared during 160 courses of myelosuppressive chemotherapy in 123 patients with acute leukaemia. After the first week, patients taking 800 mg day-1 or 400 mg day-1 (s/c1200) itraconazole solution achieved significantly higher trough concentrations (high-performance liquid chromatography) than patients in other groups (P < 0.05) and 87 and 100%, respectively, of these had concentrations > 500 ng ml-1. Contrary to a dose of 400 mg day-1, a dose of 800 mg day-1 itraconazole solution induced severe nausea and vomiting in 46% of the patients. We conclude that 400 mg day-1 itraconazole solution with a loading dose of 800 mg day-1 capsules for 7 days resulted in sufficient trough concentrations from the first week onwards and appears to be suitable for antifungal prophylaxis in neutropenic patients.

Itraconazole

Itraconazole is a broad spectrum triazole antifungal agent. It has favourable pharmacodynamic and pharmacokinetic profiles and is available as both oral and i.v. formulations. Over the last two decades, clinical and animal infection studies have demonstrated the efficacy of itraconazole in a wide range of superficial fungal infections including difficult-to-treat dermatophytoses and onychomycoses. Furthermore, shortened treatment regimens have proven to be effective, ranging from 1-day treatment for vaginal candidosis to 1-week pulse therapy per month, for 2-4 months, in onychomycosis and follicular dermatophytosis. Clinical experience with itraconazole in the treatment of deep mycoses is less comprehensive. However, results in systemic candidosis, sporotrichosis, blastomycosis, paracoccidioiodomycosis, certain types of histoplasmosis and aspergillosis are extremely encouraging. Itraconazole is less effective in the treatment of chromomycosis and coccidioidomycosis. Nevertheless, considering the refractory nature of these diseases, itraconazole has proven to be a valuable addition to the antifungal drugs currently available for treatment. Itraconazole has been well-tolerated with doses of up to 400 mg/day being generally free of serious adverse effects. However, a potential for drug interactions exists, mediated through the cytochrome P450 enzyme 3A4 system, which should be considered when itraconazole is used as part of a multi-drug regimen.

Antifungal prophylaxis in neutropenia

Despite the widespread prophylactic use of antifungal agents in neutropenic patients, invasive fungal infections continue to emerge as major causes of morbidity and mortality. With the exception of fluconazole prophylaxis in allogeneic marrow transplant recipients, no firm conclusions can be drawn due to the lack of reliable, randomized trials. At the present time, it seems that antifungal chemoprophylaxis is more a matter of faith rather than science. Earlier diagnosis based on noninvasive diagnostic techniques and pre-emptive strategies may offer more promise than a liberal prophylactic approach.

Breakthrough invasive fungal infections in neutropenic patients after prophylaxis with itraconazole

This study analyses invasive fungal infections in neutropenic patients with haematological malignancies during antifungal prophylaxis with itraconazole. From September 1994 to December 1998 20 patients developed fungal infections. Two patients suffered from disseminated infections by yeasts and 18 patients suffered from pulmonary infections by moulds (eight proven, 10 highly probable in high-resolution CT scans). In these patients the itraconazole trough concentrations exceeded 500 ng ml-1 (measured by high performance liquid chromatography) significantly less often (median 48%, interquartile range 0-100%) than in another group of 150 leukaemia patients without invasive fungal infections who received 287 courses of prophylaxis with itraconazole at our institution (median 100%, interquartile range 38-100%, P = 0.039). Twelve patients died, six of these had refractory disease. Patients with fatal invasive fungal infections had lower median itraconazole concentrations immediately before occurrence of the infection than patients with non-fatal infections: 120 (0-478) ng ml-1 versus 690 (305-1908) ng ml-1 (P = 0.039). In conclusion, this analysis of breakthrough invasive fungal infections during prophylaxis with itraconazole demonstrates that patients with itraconazole trough concentrations below 500 ng ml-1 were significantly more likely to develop fungal infections and that the last itraconazole trough concentration before occurrence of the infection was significantly lower in patients with fatal invasive fungal infections.

Fungal surveillance cultures during antifungal prophylaxis with itraconazole in neutropenic patients with acute leukaemia

Fungal colonization has been associated with an increased rate of invasive fungal infections in neutropenic patients. This study evaluates weekly fungal surveillance cultures from the oropharyngeal and perianal space as well as other suspected sites in 219 courses of myelosuppressive chemotherapy with itraconazole antifungal prophylaxis in 116 neutropenic patients with acute leukaemia. Itraconazole was given from the start of chemotherapy in one of six different dosing regimens. Fungal colonization occurred in 68 (31%) of courses, which was lower than in a historical control group without prophylaxis (53%, P = 0.004). Twenty-six per cent of these 116 isolates had a growth rate of more than 50 colony forming units (CFU) per culture. Candida glabrata (51%), Candida albicans (18%) and Candida krusei (4%) were the most frequently isolated species. Higher median itraconazole trough concentrations were associated with a lower growth rate in the cultures (< or = 50 CFU/culture versus > 50 CFU/culture): 710 (430-1180) ng ml-1 versus 900 (560-1650) ng ml-1 (P = 0.015). The use of itraconazole solution--compared with capsules--led to a reduced growth rate (P = 0.035). In conclusion, compared with historical controls itraconazole antifungal prophylaxis reduces the incidence and the extent of fungal colonization during neutropenia in patients with acute leukaemia.

Emerging Issues in Nosocomial Fungal Infections

Nosocomial fungal infections remain a serious cause of morbidity and mortality. As immunodeficient populations increase, the incidence of nosocomial fungal infections continues to rise. Although a wide variety of new and emerging fungi can cause nosocomial infections, Candida species remain the major etiologic agent. Candida species vary in their epidemiology and therapy. New diagnostic, epidemiologic, and therapeutic tools have been developed and are discussed in this review. They include the use of polymerase chain reaction-based diagnostic methods, recent advances in antifungal susceptibility testing, and comparative therapeutic and prophylactic trials. As advances in prevention, diagnosis, and therapy continue, nosocomial fungal infections and the morbidity and mortality associated with them can be reduced.