Caspofungin versus liposomal amphotericin B for empirical antifungal therapy in patients with persistent fever and neutropenia

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.

Management of invasive pulmonary aspergillosis in non-neutropenic critically ill patients

During recent years, a rising incidence of invasive pulmonary aspergillosis (IPA) in non-neutropenic critically ill patients has been reported. Critically ill patients are prone to develop disturbances in immunoregulation during their stay in the ICU, which render them more vulnerable for fungal infections. Risk factors such as chronic obstructive pulmonary disease (COPD), prolonged use of steroids, advanced liver disease, chronic renal replacement therapy, near-drowning and diabetes mellitus have been described. Diagnosis of IPA may be difficult and obtaining histo- or cytopathological demonstration of the fungus in order to meet the gold standard for IPA is not always feasible in these patients. Laboratory markers used as a non-invasive diagnostic tool, such as the galactomannan antigen test (GM), 1,3-beta-glucan, and Aspergillus PCR, show varying results. Antifungal therapy might be considered in patients with persistent pulmonary infection who exhibit risk factors together with positive cultures or sequentially positive GM and Aspergillus PCR in serum, in whom voriconazole is the drug of choice. The benefit of combination antifungal therapy lacks sufficient evidence so far, but this treatment might be considered in patients with breakthrough infections or refractory disease.

Single- and multiple-dose administration of caspofungin in patients with hepatic insufficiency: implications for safety and dosing recommendations

This report investigated safety and dosing recommendations of intravenous caspofungin in hepatic insufficiency. In the single-dose study, 8 patients each with mild and moderate hepatic insufficiency received 70 mg of caspofungin. In the multiple-dose study, 8 patients with mild hepatic insufficiency and 13 healthy matched controls received 70 mg on day 1 and 50 mg daily on days 2 through 14. Eight patients with moderate hepatic insufficiency received 70 mg on day 1 and 35 mg daily on days 2 through 14. Caspofungin was generally well tolerated with no discontinuations due to serious or nonserious adverse experiences. The area under the concentration-time profile over the interval of last quantifiable point to infinity (AUC(0-infinity)) geometric mean ratio (GMR) (90% confidence interval [CI]) for mild hepatic insufficiency/historical controls was 1.55 (1.32-1.86) in the single-dose study and for mild hepatic insufficiency/concurrent controls was 1.21 (1.04-1.39) for day 14 area under the concentration-time profile calculated over the interval 0 to 24 hours (AUC(0-24h)) following multidose. The AUC(0-infinity) GMR (90% CI) for moderate hepatic insufficiency/historical controls was 1.76 (1.51-2.06) following 70 mg; AUC(0-24h) GMR (90% CI) for moderate hepatic insufficiency/concurrent controls was 1.07 (0.90-1.28) on day 14 after 35 mg daily. No dosage adjustment is recommended for patients with mild hepatic insufficiency. A dosage reduction to 35 mg daily following the 70-mg loading dose is recommended for patients with moderate hepatic insufficiency.

Renal disease in recipients of nonrenal solid organ transplantation

Worldwide, more than 250,000 individuals who have received a liver, heart, lung, or intestinal transplant are living longer. Twenty percent to 25% of these recipients experience perioperative acute renal failure, with 10% to 15% requiring renal replacement therapy. Chronic kidney disease (CKD) is also highly prevalent, affecting 30% to 50% of the nonrenal organ transplant population with an annual end-stage renal disease risk of 1.5% to 2.0%. Both acute renal failure and CKD contribute to increased morbidity and premature mortality. The dominant causative factor for renal disorders seen in nonrenal transplant recipients are the calcineurin inhibitors (CNI) and rapamycin analogues, which singly or in combination lead to a variety of nephrotoxic injury. However, 25% to 30% of nonrenal transplant recipients with CKD have other conditions such as hypertension, focal segmental glomerulosclerosis, diabetes mellitus, and hepatitis C infection as the principal underlying cause. Management strategies for renal disease in the nonrenal transplant recipients include the following: (1) delayed introduction of CNI after graft implantation, (2) withdrawal or minimization of long-term CNI therapy, (3) timely use of an appropriate dialysis modality, and (4) expeditious introduction of supportive measures such as anemia management, phosphate binding therapy, and dietary modification. Compared with maintenance dialysis, kidney transplantation reduces long-term mortality by 60% to 70% in nonrenal transplant recipients with end-stage renal disease.

Candidemia in the in-patient setting: treatment options and economics

Candidemia is the most common nosocomial fungal infection in the US. More than one in four adults who acquire candidemia in the hospital setting die prior to discharge. In addition to high case-fatality rates and other adverse clinical outcomes in survivors, candidemia is associated with a substantial economic burden. High costs associated with complex diagnostics and procedures contribute to this burden, as do new pharmacotherapeutic approaches. Despite the high costs of many antifungal agents recommended for the treatment of candidemia, unambiguous clinical evidence to guide treatment selection does not exist. This article reviews the clinical and economic burdens of candidemia, describes candidemia cost drivers and discusses existing pharmacoeconomic data regarding the cost-effectiveness of candidemia rapid identification and treatment approaches.

Efficacy and safety of caspofungin for the empiric management of fever in neutropenic children

This retrospective review evaluates the response to caspofungin when given to children with febrile neutropenia and describes adverse effects attributable to caspofungin, including risk of hepatotoxicity during concomitant therapy with cyclosporine. Sixty-seven courses of caspofungin administered to 56 patients (1-17 years) were surveyed; 53 (79%) courses resulted in an overall favorable response. Ten children (15% of courses) experienced an adverse drug-related event that was probably or possibly attributable to caspofungin. Rash and hypokalemia were the most commonly identified adverse effects. One of 19 children receiving caspofungin and cyclosporine concurrently developed hepatotoxicity possibly related to caspofungin.

Successful treatment of refractory chronic disseminated candidiasis after prolonged administration of caspofungin in a child with acute myeloid leukemia

This report documents the clinical activity of caspofungin in a 13-year-old girl with acute myeloid leukemia (AML) and chronic disseminated candidiasis (CDC), refractory to amphotericin B and fluconazole. Caspofungin was started at 50 mg/d resulting in a temporary response. With no further clinical improvement and radiological progress after 2 months of therapy, the dose of caspofungin was increased to 100 mg/d, leading to a sustained clinical response. Therapy was given for a total of 12 months and had no attributable adverse effects. This approach resulted in successful treatment of refractory CDC with caspofungin.

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.

Fulminant mulch pneumonitis: an emergency presentation of chronic granulomatous disease

BACKGROUND

Chronic granulomatous disease (CGD) is associated with multiple and recurrent infections. In patients with CGD, invasive pulmonary infection with Aspergillus species remains the greatest cause of mortality and is typically insidious in onset. Acute fulminant presentations of fungal pneumonia are catastrophic.

METHODS

Case records, radiograph findings, and microbiologic examination findings of patients with CGD who had acute presentations of dyspnea and diffuse pulmonary infiltrates caused by invasive fungal infection were reviewed and excerpted onto a standard format.

RESULTS

From 1991 through 2004, 9 patients who either were known to have CGD or who received a subsequent diagnosis of CGD presented with fever and new onset dyspnea. Eight patients were hypoxic at presentation; bilateral pulmonary infiltrates were noted at presentation in 6 patients and developed within 2 days after initial symptoms in 2 patients. All patients received diagnoses of invasive filamentous fungi; 4 patients had specimens that also grew Streptomyces species on culture. All patients had been exposed to aerosolized mulch or organic material 1-10 days prior to the onset of symptoms. Cases did not occur in the winter. Five patients died. Two patients, 14 years of age and 23 years of age, who had no antecedent history of recognized immunodeficiency, were found to have p47(phox)-deficient CGD.

CONCLUSIONS

Acute fulminant invasive fungal pneumonia in the absence of exogenous immunosuppression is a medical emergency that is highly associated with CGD. Correct diagnosis has important implications for immediate therapy, genetic counseling, and subsequent prophylaxis.

Influence of amphotericin B and amphotericin B colloidal dispersion on the functions of human phagocytes in defence against Aspergillus species

This study investigated the in vitro effects of amphotericin B and amphotericin B colloidal dispersion (ABCD) on phagocytosis and inhibition of germination of clinical isolates of Aspergillus spp. by monocyte-derived macrophages (MDMs). Both amphotericin B and ABCD caused significant reductions in uptake of conidia of Aspergillus spp. by MDMs (p < 0.01). The inhibition of germination was superior with conidia of Aspergillus fumigatus, Aspergillus niger and Aspergillus terreus isolates. Aspergillus flavus growth was significantly less inhibited of either antimycotic as compared to A. fumigatus and A. terreus (p < 0.01).We demonstrate that amphotericin B or ABCD acts as a potent inhibitor of Aspergillus germination. By contrast, treatment of MDMs with these antimycotics diminished phagocytosis of conidia in vitro.

Recent advances in antifungal chemotherapy

For over 50 years, amphotericin B deoxycholate (AmBD) has been the 'gold standard' in antifungal chemotherapy, despite its frequent toxicities. However, improved treatment options for invasive fungal infections (IFIs) have been developed during the last 15 years. Newer antifungal agents, including less toxic lipid preparations of AmBD, triazoles and the echinocandins, have been added to our armamentarium against IFIs. Some of these newer drugs can now replace AmBD as primary therapy (e.g. caspofungin for candidiasis, voriconazole for aspergillosis), whilst others offer new therapeutic options for difficult-to-treat IFIs (e.g. posaconazole for zygomycosis, fusariosis and chromoblastomycosis). It is interesting that extended use of newer antifungals such as fluconazole, despite decreasing the mortality attributed to candidiasis, resulted in selection of species resistant to several antifungals (Candida krusei, Candida glabrata); whilst several publications suggest that prolonged use of voriconazole may expose severely immunocompromised patients to the risk of zygomycosis (breakthrough). On the other hand, the differences in the mode of action of newer antifungals such as echinocandins raise the question whether combination antifungal therapy is more effective than monotherapy. Finally, the availability of an oral formulation with excellent biosafety of several newer antifungals (e.g. posaconazole) makes them candidates for prophylactic or prolonged maintenance therapy.

The pharmacology and clinical use of caspofungin

Caspofungin was the first echinocandin to be licensed for the treatment of invasive fungal infections. Caspofungin has in vitro and in vivo activity against Candida spp. and Aspergillus spp., which constitute the majority of medically important opportunistic fungal pathogens. Caspofungin inhibits the synthesis of the 1,3-beta-glucan, with resultant osmotic instability and lysis. The pharmacology of caspofungin is relatively complex. Trafficking of drug into tissues is an important determinant of the shape of the concentration-time relationship. Caspofungin has demonstrated efficacy in experimental models of invasive candidiasis and aspergillosis, which reflect its activity in the treatment of oropharyngeal, esophageal and disseminated candidiasis, as well as salvage therapy for patients with invasive aspergillosis.

A comparative evaluation of properties and clinical efficacy of the echinocandins

With the increase in prevalence of fungal infections, newer antifungal agents are needed to effectively treat invasive disease, and at the same time minimize adverse effects from therapy. The echinocandins comprise a novel class of antifungals; their mechanism of action involves inhibiting 1,3-beta-D-glucan synthase, which is essential in cell wall synthesis for certain fungi. All three echinocandins are US FDA-approved for the treatment of esophageal candidiasis. Caspofungin and anidulafungin are licensed for the treatment of candidemia, and other select forms of invasive candidiasis. Micafungin is at present the only echinocandin approved for prophylaxis of fungal infections in hematopoietic stem cell transplants; whereas caspofungin is approved for empiric therapy of febrile neutropenia. Although all three echinocandins are active against Aspergillus, only caspofungin is presently approved for salvage therapy in invasive aspergillosis. Combination therapy with echinocandins plus other licensed antifungal therapy shows promise in treating invasive aspergillosis. This article will explore the similarities and differences among the echinocandins.

Institutional Experience with Voriconazole Compared with Liposomal Amphotericin B as Empiric Therapy for Febrile Neutropenia

STUDY OBJECTIVE

To assess the effectiveness, safety, and cost of empiric treatment of febrile neutropenia before and after implementing an algorithm in which voriconazole was substituted for liposomal amphotericin B (L-AmB).

DESIGN

Retrospective cohort analysis.

SETTING

An 850-bed tertiary care hospital, which is also a referral site for patients with acute leukemia.

PATIENTS

Fifty-five adult patients who started empiric antifungal therapy for febrile neutropenia between January 1, 2002, and December 31, 2003, encompassing 58 treatment episodes (defined as a hospitalization during which empiric antifungal therapy was administered).

MEASUREMENTS AND MAIN RESULTS

Medical charts, including patients' pharmacy and laboratory data, were reviewed. Twenty-six and 32 episodes of L-AmB and voriconazole use, respectively, were identified. No significant differences between the L-AmB and voriconazole groups were noted at baseline. Rates of fever resolution (54% vs 59%, p=0.791) and breakthrough invasive fungal infections (11% vs 12%, p>0.999) were similar for the L-AmB and voriconazole episodes. Premature drug discontinuation due to the prescriber's perceived lack of efficacy occurred most frequently in the voriconazole group (25% vs 8%, p=0.160). Survival was significantly higher in the voriconazole than in the L-AmB group (100% vs 77%, p=0.006). Adverse effects that were significantly more common in the L-AmB group than in the voriconazole group were elevated serum creatinine levels (27% vs 3%, p=0.017) and electrolyte disturbances (19% vs 0%, p=0.014). Adverse effects reported more frequently in the voriconazole group than in the L-AmB group were visual disturbances (9% vs 0%, p=0.245) and elevated hepatic enzyme levels (9% vs 8%, p>0.999). Mean drug expenditures/episode for initial empiric antifungal therapy were lower for voriconazole than for L-AmB ($1593 vs $4144, or $153 vs $380/day).

CONCLUSION

Our institution's algorithm incorporating voriconazole into the empiric management of febrile neutropenia was associated with effectiveness outcomes comparable to those observed with L-AmB as well as a lower frequency of adverse effects and overall expenditures for antifungal drugs.

Itraconazole IV nanosuspension enhances efficacy through altered pharmacokinetics in the rat

The goal of this research was to evaluate an intravenous itraconazole nanosuspension dosage form, relative to a solution formulation, in the rat. Itraconazole was formulated as a nanosuspension by a tandem process of microcrystallization followed by homogenization. Acute toxicity, pharmacokinetics, and distribution were studied in the rat, and compared with a solution formulation of itraconazole. Efficacy was studied in an immunocompromised rat model, challenged with a lethal dose of either itraconazole-sensitive or itraconazole-resistant C. albicans. Itraconazole nanosuspension was tolerated at significantly higher doses compared with a solution formulation. Pharmacokinetics of the nanosuspension were altered relative to the solution formulation. C(max) was reduced and t(1/2) was much prolonged. This occurred due to distribution of the nanosuspension to organs of the monocyte phagocytic system (MPS), followed by sustained release from this IV depot. The higher dosing of the drug, enabled in the case of the nanosuspension, led to higher kidney drug levels and reduced colony counts. Survival was also shown to be superior relative to the solution formulation. Thus, formulation of itraconazole as a nanosuspension enhances efficacy of this antifungal agent relative to a solution formulation, because of altered pharmacokinetics, leading to increased tolerability, permitting higher dosing and resultant tissue drug levels.

Advances in topical and systemic antifungals

Topical antifungal agents are generally used for the treatment of superficial fungal infections unless the infection is widespread, involves an extensive area, or is resistant to initial therapy. Systemic antifungals are often reserved for the treatment of onychomycosis, tinea capitis, superficial and systemic candidiasis, and prophylaxis and treatment of invasive fungal infections. With the development of resistant fungi strains and the increased incidence of life-threatening invasive fungal infections in immunocompromised patients, some previously effective traditional antifungal agents are subject to limitations including multidrug interactions, severe adverse effects, and their fungistatic mechanism of actions. Several new antifungal agents have demonstrated significant therapeutic benefits and have broadened clinicians' choices in the treatment of superficial and systemic invasive fungal infections.

Presumptive treatment strategy for aspergillosis in allogeneic haematopoietic stem cell transplant recipients

BACKGROUND

The onset of invasive aspergillosis (IA) after allogeneic haematopoietic stem cell transplantation (HSCT) is bimodal. However, IA early after HSCT has become less frequent due to the shortened neutropenic period, and the clinical significance of empirical treatment for aspergillosis based on persistent febrile neutropenia (FN) became less clear. Therefore, we started a presumptive treatment strategy, in which anti-Aspergillus agents were started when patients developed positive serum test and/or infiltrates or nodules on X-ray or CT-scan associated with persistent FN, in 2002.

METHODS

We retrospectively reviewed the records of 114 adult patients who underwent allogeneic HSCT between September 2002 and December 2005 in high-efficiency particulate air-filtered clean rooms. Fluconazole was given as anti-Candida prophylaxis. The primary endpoint was the development of early IA, which was defined as probable or proven IA according to the EORTC/MSG criteria that developed between the day of HSCT and 7 days after engraftment.

RESULTS

Among 73 patients who experienced persistent FN for 7 days or longer, anti-Aspergillus agents were empirically started in 13 patients at the discretion of attending physicians, whereas 60 patients actually followed presumptive treatment strategy. Only 4 of 60 patients received anti-Aspergillus agents. Two patients in the presumptive group developed early IA, but were successfully treated with anti-Aspergillus agents started after the diagnosis of IA.

CONCLUSIONS

These findings suggested the feasibility of a presumptive treatment strategy for aspergillosis in HSCT recipients. A randomized controlled trial is warranted to compare empirical and presumptive anti-Aspergillus strategy in allogeneic HSCT recipients.

Resistance to echinocandin-class antifungal drugs

Invasive fungal infections cause morbidity and mortality in severely ill patients, and limited drug classes restrict treatment choices. The echinocandin drugs are the first new class of antifungal compounds that target the fungal cell wall by blocking beta-1,3-d-glucan synthase. Elevated MIC values with occasional treatment failure have been reported for strains of Candida. Yet, an uncertain correlation exists between clinical failure and elevated MIC values for the echinocandin drugs. Fungi display several adaptive physiological mechanisms that result in elevated MIC values. However, resistance to echinocandin drugs among clinical isolates is associated with amino acid substitutions in two "hot-spot" regions of Fks1, the major subunit of glucan synthase. The mutations, yielding highly elevated MIC values, are genetically dominant and confer cross-resistance to all echinocandin drugs. Prominent Fks1 mutations decrease the sensitivity of glucan synthase for drug by 1000-fold or more, and strains harboring such mutations may require a concomitant increase in drug to reduce fungal organ burdens in animal infection models. The Fks1-mediated resistance mechanism is conserved in a wide variety of Candida spp. and can account for intrinsic reduced susceptibility of certain species. Fks1 mutations confer resistance in both yeasts and moulds suggesting that this mechanism is pervasive in the fungal kingdom.

A retrospective nationwide case study on the use of a new antifungal agent: patients treated with caspofungin during 2001–2004 in Finland

The aim of this study was to evaluate the efficacy and safety of caspofungin in patients treated in Finland during the period 2001-2004. The medical records of 78 adult patients treated with caspofungin in five major hospitals were reviewed retrospectively. Fifty-nine (76%) patients had proven invasive fungal infection, of whom 22 (28%) had aspergillosis and 37 (47%) had candidiasis. Nineteen (24%) patients were treated empirically; only 13 (17%) patients received caspofungin as primary therapy. A favourable response was achieved in 52 (67%) patients. The response rate was 78% in patients with candidiasis, and 50% in patients with aspergillosis. At the end of the study period, 40 (51%) patients remained alive; of the 38 deaths, nine (24%) were caused by fungal infection. The response rates were lower, although not significantly, for patients with high (>20) vs. low (< or =20) Acute Physiology and Chronic Health Evaluation (APACHE II) scores (response rate 50% vs. 68%, p 0.48, respectively), and were also lower in patients with long-term (>20 days) vs. shorter duration (< or =20 days) neutropenia (55% vs. 73%, p 0.32, respectively), and in those with an underlying haematological malignancy vs. patients with other diseases (59% vs. 73%, p 0.2, respectively). In five (6%) patients, caspofungin therapy was discontinued prematurely because of adverse drug reactions (ADRs) (elevated liver enzyme values in three patients, neuropathic pain in one, and skin rash in one). Serious ADRs occurred in two (3%) patients (severe hepatic insufficiency with consequent death, and eosinophilia with elevated alkaline phosphatase levels), and laboratory abnormalities, mostly mild and reversible, in 24 (31%) patients. In this unselected patient population, caspofungin was safe, well-tolerated, and had an efficacy comparable to that in previous reports from prospective trials.

Efficacy of caspofungin as secondary prophylaxis in patients undergoing allogeneic stem cell transplantation with prior pulmonary and/or systemic fungal infection

Transplanted patients with a history of invasive fungal infection (IFI) are at high risk of developing relapse and fatal complications. Eighteen patients affected by hematological malignancies and a previous IFI were submitted to allogeneic stem cell transplantation, using Caspofungin as a secondary prophylaxis. Patients had a probable or proven fungal infection and 16 had a pulmonary localization. No side effects were recorded during treatment with Caspofungin. Compared to pre-transplant evaluation, stability or improvement of the previous IFI was observed in 16 of the 18 patients at day 30, in 13 of the 15 evaluable patients at day 180 and in 11 of the 11 evaluable patients at day 360 post transplant. In particular, all the six patients with a proven fungal infection were alive, with a stable or improved IFI after 1 year from transplant. At a maximum follow-up of 31 months, eight patients died for disease progression or transplant-related complications, but only two had evidence of fungal progression. Secondary prophylaxis with Caspofungin may represent a suitable approach to limit IFI relapse or progression, allowing patients with hematological malignancies to adhere to the planned therapeutic program.

Invasive candidiasis in pediatric intensive care patients: epidemiology, risk factors, management, and outcome

BACKGROUND

The incidence of candidemia in pediatric patients follows the same pattern of increase as in adults, but the rate of increase is greater. Pediatric patients in critical condition, particularly young infants, are especially vulnerable to invasive Candida infections (ICI), partly because of their age and severe underlying disease and partly because of the invasive procedures used.

DISCUSSION

Central venous catheters and arterial lines, parenteral nutrition, mechanical ventilation and extended use of antimicrobials enhance the risk of ICI. C. albicans continues to be the most prevalent isolate. However, an increasing role of non-C. albicans (NAC) spp., some of which are intrinsically or potentially resistant to antifungal agents, has been observed. NAC spp., particularly C. parapsilosis and C. tropicalis, account for almost half of ICI. The increased use of antifungals in immunocompromised patients, mainly prophylactically, is considered the strongest contributory factor to the changes in species distribution, which have subsequently affected the mortality and choice of empirical treatment.

CONCLUSIONS

Prompt removal of lines and initiation of antifungal treatment are the milestones of management. Conventional amphotericin B remains a commonly used antifungal agent, but its lipid formulations and fluconazole are also used frequently. Novel antifungal agents such as second-generation triazoles and echinocandins exhibit potential as alternative agents in critically ill children with ICI. Although response rates are still far from satisfactory, improved understanding of risk factors, preventive strategies and new treatment options promise a better future outcome.

Empirical antimicrobial treatment for chemotherapy-induced febrile neutropenia

Febrile neutropenia in immunocompromised hosts is associated with a high mortality. Empirical treatment in such cases is instituted to cover the common pathogens. Generally, combination antibiotic treatment is used early in the febrile neutropenia phase. Recent studies demonstrate that monotherapy with certain beta-lactam antibiotics can be equally effective. Glycopeptide antibiotics are used in the absence of an adequate response to the initial antibiotics. Empirical antifungal therapy may be given if fever does not settle in 72-96 h despite antibiotics. Newer antifungal agents have increased the available options for initial antifungal agents though more data are needed before any conclusive recommendation can be made. Recent changes in the epidemiology of multiresistant organisms necessitate local microbiological input into empiric policies with increasing need to consider cover for methicillin-resistant Staphylococcus aureus, glycopeptide intermediate S. aureus, vancomycin-resistant S. aureus, vancomycin-resistant enterococci, Gram-negative bacilli that produce extended-spectrum beta-lactamases, Stenotrophomonas maltophilia, and multi-resistant Acinetobacter baumanii.

Interventions for treating oral candidiasis for patients with cancer receiving treatment

BACKGROUND

Treatment of cancer is increasingly effective but is associated with short and long term side effects. Oral side effects, including oral candidiasis, remain a major source of illness despite the use of a variety of agents to treat them.

OBJECTIVES

To assess the effectiveness of interventions for the treatment of oral candidiasis for patients with cancer receiving chemotherapy or radiotherapy or both.

SEARCH STRATEGY

Computerised searches of Cochrane Oral Health Group and PaPaS Trials Registers, CENTRAL, MEDLINE, EMBASE, CINAHL, CANCERLIT, SIGLE and LILACS were undertaken. Reference lists from relevant articles were searched and the authors of eligible trials were contacted to identify trials and obtain additional information. Date of the most recent searches: June 2006: CENTRAL (The Cochrane Library 2006, Issue 2).

SELECTION CRITERIA

All randomised controlled trials comparing agents prescribed to treat oral candidiasis in people receiving chemotherapy or radiotherapy for cancer. The outcomes were eradication of oral candidiasis, dysphagia, systemic infection, amount of analgesia, length of hospitalisation, cost and patient quality of life.

DATA COLLECTION AND ANALYSIS

Data were independently extracted, in duplicate, by two review authors. Authors were contacted for details of randomisation and withdrawals and a quality assessment was carried out. Risk ratios were calculated using random-effects models.

MAIN RESULTS

Nine trials involving 658 patients, satisfied the inclusion criteria and are included in this review. Only two agents, each in single trials, were found to be effective for eradicating oral candidiasis. A drug absorbed from the gastrointestinal tract, ketoconazole, was more beneficial than placebo in eradicating oral candidiasis (risk ratio (RR) = 3.61, 95% confidence interval (CI) 1.47 to 8.88) and clotrimazole, at a higher dose of 50 mg was more effective than a lower 10 mg dose in eradicating oral candidiasis, when assessed mycologically (RR = 2.00, 95% CI 1.11 to 3.60). Of the five trials included in these meta-analyses, three were at high risk of bias and two of moderate risk of bias. Another trial demonstrated no statistically significant difference between a 10 mg dose of the partially absorbed drug, clotrimazole, and placebo. No differences were found when comparing different absorbed drugs; and comparing absorbed drugs with drugs which are not absorbed.

AUTHORS' CONCLUSIONS

There is weak and unreliable evidence that the absorbed drug, ketoconazole, may eradicate oral candidiasis and that a higher dose of the partially absorbed drug, clotrimazole, may give greater benefit than a lower 10 mg dose, however, researchers may wish to prevent rather than treat oral candidiasis. Further well designed, placebo-controlled trials assessing the effectiveness of old and new interventions for treating oral candidiasis are needed.

Liposomal amphotericin B as initial therapy for invasive mold infection: a randomized trial comparing a high-loading dose regimen with standard dosing (AmBiLoad trial)

BACKGROUND

Treatment of invasive mold infection in immunocompromised patients remains challenging. Voriconazole has been shown to have efficacy and survival benefits over amphotericin B deoxycholate, but its utility is limited by drug interactions. Liposomal amphotericin B achieves maximum plasma levels at a dosage of 10 mg/kg per day, but clinical efficacy data for higher doses are lacking.

METHODS

In a double-blind trial, patients with proven or probable invasive mold infection were randomized to receive liposomal amphotericin B at either 3 or 10 mg/kg per day for 14 days, followed by 3 mg/kg per day. The primary end point was favorable (i.e., complete or partial) response at the end of study drug treatment. Survival and safety outcomes were also evaluated.

RESULTS

Of 201 patients with confirmed invasive mold infection, 107 received the 3-mg/kg daily dose, and 94 received the 10-mg/kg daily dose. Invasive aspergillosis accounted for 97% of cases. Hematological malignancies were present in 93% of patients, and 73% of patients were neutropenic at baseline. A favorable response was achieved in 50% and 46% of patients in the 3- and 10-mg/kg groups, respectively (difference, 4%; 95% confidence interval, -10% to 18%; P>.05); the respective survival rates at 12 weeks were 72% and 59% (difference, 13%; 95% confidence interval, -0.2% to 26%; P>.05). Significantly higher rates of nephrotoxicity and hypokalemia were seen in the high-dose group.

CONCLUSIONS

In highly immunocompromised patients, the effectiveness of 3 mg/kg of liposomal amphotericin B per day as first-line therapy for invasive aspergillosis is demonstrated, with a response rate of 50% and a 12-week survival rate of 72%. The regimen of 10 mg/kg per day demonstrated no additional benefit and higher rates of nephrotoxicity.

A cost-effectiveness analysis of caspofungin vs. liposomal amphotericin B for treatment of suspected fungal infections in the UK

Objective:

To evaluate the cost-effectiveness of caspofungin vs. liposomal amphotericin B in the treatment of suspected fungal infections in the UK.

Methods:

The cost-effectiveness of caspofungin vs. liposomal amphotericin B was evaluated using a decision-tree model. The decision tree was populated using both data and clinical definitions from published clinical studies. Model outcomes included success in terms of resolution of fever, baseline infection, absence of breakthrough infection, survival and quality adjusted life years (QALYs) saved. Discontinuation due to nephrotoxicity or other adverse events were included in the model. Efficacy and safety data were based on additional analyses of a randomised, double blind, multinational trial of caspofungin compared with liposomal amphotericin B. Information on life expectancy, quality of life, medical resource consumption and costs were obtained from peer-reviewed published data.

Results:

The caspofungin mean total treatment cost was £9762 (95% uncertainty interval 6955–12 577), which was £2033 (−2489; 6779) less than liposomal amphotericin B. Treatment with caspofungin resulted in 0.40 (−0.12; 0.94) additional QALYs saved in comparison with liposomal amphotericin B. Probabilistic sensitivity analysis found a 95% probability of the incremental cost per QALY saved being within the generally accepted threshold for cost-effectiveness (£30 000). Additional analyses with varying dose of caspofungin and liposomal amphotericin B confirmed these findings.

Conclusion:

Given the underlying assumptions, caspofungin is cost-effective compared with liposomal amphotericin B in the treatment of suspected fungal infections in the UK.

Antifungal therapy in children with invasive fungal infections: a systematic review

Invasive fungal infections are associated with significant morbidity and mortality. Differences between children and adults are reported, yet few trials of antifungal agents have been performed in pediatric populations. We performed a systematic review of the literature to guide appropriate pediatric treatment recommendations. From available trials that compared antifungal agents in either prolonged febrile neutropenia or invasive candidal or Aspergillus infection, no clear difference in treatment efficacy was demonstrated, although few trials were adequately powered. Differing antifungal pharmacokinetics between children and adults were demonstrated, requiring dose modification. Significant differences in toxicity, particularly nephrotoxicity, were identified between classes of antifungal agents. Therapy needs to be guided by the pathogen or suspected pathogens, the degree of immunosuppression, comorbidities (particularly renal dysfunction), concurrent nephrotoxins, and the expected length of therapy.

Liquid chromatography-mass spectrometry method for quantification of caspofungin in clinical plasma samples

Caspofungin [(CASPO) MK-0991] is the first broad-spectrum anti-fungal agent of the echinocandin class approved for clinical use. Measurement of CASPO levels in blood might help monitor therapy in patients who are critically ill, in particular, if high-dose regimens or combinations of CASPO with other anti-fungals are used. The objective of this study was to develop a fast method for the measurement of CASPO levels in clinical blood samples using liquid chromatography coupled to a triple-quadrupole mass spectrometer. Stock solutions were prepared in plasma to avoid CASPO adsorption to glass and plastic surfaces during processing. CASPO and the internal standard (IS) were extracted from 100 microl of plasma using acetonitrile protein precipitation. The supernatant was diluted and directly injected into an analytical column (C8; 2.1 x 30 mm). The total run time was 15 min. CASPO was ionized by electrospray in the positive mode. CASPO and IS [M + 2H]2+ parent ions (m/z 547.3 and 547.8, respectively) and specific product ions (m/z 137.1 and 62.2, respectively) were used for the ion transitions. No carry over or cross-talk was observed on the column. The mean method recovery was 90 +/- 3%. Neither blood from different individuals (n = 6) nor the presence of concomitant drugs (n = 33) in plasma samples interfered with CASPO quantification. Quantification over time of the CASPO levels in plasma and whole blood was investigated at different pre-analysis storage conditions. The calibration curve included the clinically relevant CASPO concentration range from 0.04 to 20 microg/ml. Mean intra- and inter-day accuracy was 96.1 +/- 2.2% and 102.5 +/- 2.4%, respectively. Mean intra- and inter-day precision was 7.9 +/- 3.2% and 6.3 +/- 1.8%, respectively. This simple and robust liquid chromatography-tandem mass spectrometry (LC-MS/MS) method may easily be implemented for monitoring CASPO therapy.

Safety and efficacy of itraconazole compared to amphotericin B as empirical antifungal therapy for neutropenic fever in patients with haematological malignancy

BACKGROUND

Safety, tolerability and efficacy of itraconazole and amphotericin B (AMB) were compared for empirical antifungal treatment of febrile neutropenic cancer patients.

PATIENTS AND METHODS

In an open, randomised study, 162 patients with at least 72 h of antimicrobial treatment received either intravenous followed by oral itraconazole suspension or intravenous AMB for a maximum of 28 days. Permanent discontinuation of study medication due to any adverse event was the primary safety parameter. Efficacy parameters included response and success rate for both treatment groups.

RESULTS

Significantly fewer itraconazole patients discontinued treatment due to any adverse event (22.2 vs. 56.8% AMB; p < 0.0001). The main reason for discontinuation was a rise in serum creatinine (1.2% itraconazole vs. 23.5% AMB). Renal toxicity was significantly higher and more drug-related adverse events occurred in the AMB group. Intention-to-treat (ITT) analysis showed favourable efficacy for itraconazole: response and success rate were both significantly higher than for AMB (61.7 vs. 42% and 70.4 vs. 49.3%, both p < 0.0001). Treatment failure was markedly reduced in itraconazole patients (25.9 vs. 43.2%), largely due to the better tolerability.

CONCLUSIONS

Itraconazole was tolerated significantly better than conventional AMB and also showed advantages regarding efficacy. This study confirms the role of itraconazole as a useful and safe agent in empirical antifungal therapy of febrile neutropenic cancer patients.

Pharmacoeconomic analysis of caspofungin versus liposomal amphotericin B as empirical antifungal therapy for neutropenic fever

PURPOSE

An analysis was conducted that evaluated and compared the cost differences between caspofungin and liposomal amphotericin B when the medications were used as empirical antifungal therapy for persistent fever during neutropenia.

METHODS

Rates of drug use and impaired renal function (IRF) were based on data from published studies. IRF was defined as a doubling of the serum creatinine level or, if the creatinine level was elevated at enrollment, an increase of at least 1 mg/dL. The estimates of the costs for drug acquisition and treating IRF were derived using published data and applied to compare caspofungin with liposomal amphotericin B. Sensitivity analyses were performed by varying the IRF and relative acquisition costs to assess the effect of these factors on the cost differences.

RESULTS

The acquisition costs per patient were 6942 dollars for liposomal amphotericin B and 3996 dollars for caspofungin. The estimated cost per patient from IRF was 3173 dollars for liposomal amphotericin B and 793 dollars for caspofungin. Combining drug acquisition and IRF costs, the overall treatment cost per patient for caspofungin was 5326 dollars less than for liposomal amphotericin B. In sensitivity analyses of drug costs, the price of liposomal amphotericin B would have to be 23.95 dollars per vial for the overall treatment costs to be equal.

CONCLUSION

Comparison of cost estimates derived from published data revealed that a combined estimate of acquisition costs and costs related to the treatment of IRF was lower for caspofungin than for liposomal amphotericin B for empirically treating patients with neutropenic fever.

Synthesis of the Antifungal β-1,3-Glucan Synthase Inhibitor CANCIDAS (Caspofungin Acetate) from Pneumocandin B0

A novel three-step synthesis of the highly functionalized antifungal agent CANCIDAS (caspofungin acetate, 2) is described, starting from the natural product pneumocandin B0 (1). The highlights of the synthesis include a stereoselective formation of a phenylthioaminal, a remarkable chemoselective, high-yielding, one-step borane reduction of a primary amide, and a stereoselective substitution of the phenylthioaminal with ethylenediamine producing 2 in a 45% overall yield.

Medicinal importance of fungal beta-(1-->3), (1-->6)-glucans

Non-cellulosic beta-glucans are now recognized as potent immunological activators, and some are used clinically in China and Japan. These beta-glucans consist of a backbone of glucose residues linked by beta-(1-->3)-glycosidic bonds, often with attached side-chain glucose residues joined by beta-(1-->6) linkages. The frequency of branching varies. The literature suggests beta-glucans are effective in treating diseases like cancer, a range of microbial infections, hypercholesterolaemia, and diabetes. Their mechanisms of action involve them being recognized as non-self molecules, so the immune system is stimulated by their presence. Several receptors have been identified, which include: dectin-1, located on macrophages, which mediates beta-glucan activation of phagocytosis and production of cytokines, a response co-ordinated by the toll-like receptor-2. Activated complement receptors on natural killer cells, neutrophils, and lymphocytes, may also be associated with tumour cytotoxicity. Two other receptors, scavenger and lactosylceramide, bind beta-glucans and mediate a series of signal pathways leading to immunological activation. Structurally different beta-glucans appear to have different affinities toward these receptors and thus generate markedly different host responses. However, the published data are not always easy to interpret as many of the earlier studies used crude beta-glucan preparations with, for the most part, unknown chemical structures. Careful choice of beta-glucan products is essential if their benefits are to be optimized, and a better understanding of how beta-glucans bind to receptors should enable more efficient use of their biological activities.

The Echinocandins

The changing pattern in fungal infections has driven the need to expand the targets of antifungal activity. The echinocandins are the newest addition to the arsenal against fungal infections. Three echinocandins have been approved by the United States Food and Drug Administration: caspofungin, micafungin, and anidulafungin. These agents have a broad spectrum of activity and are similar to each other with respect to in vitro activity against Candida sp, with micafungin and anidulafungin having similar minimum inhibitory concentrations (MICs) that are generally lower than the MIC of capsofungin. The MICs of the echinocandins are highest against Candida parapsilosis; however, whether this will affect clinical outcomes is unknown. Several case reports have identified clinical failure due to elevated MICs with caspofungin or micafungin against Candida albicans, Candida krusei, and C. parapsilosis. Resistance to the echinocandin class was present in some but not all of the isolates. Empiric therapy with one of the echinocandins for candidemia or invasive candidiasis in patients with neutropenia and those without neutropenia appears to be appropriate when one factors in mortality rate, the increasing frequency of non-albicans Candida infections, and the broad spectrum, safety, and fungicidal effect of the echinocandins. After speciation of the organism, continued therapy with an echinocandin can and should be reevaluated. The echinocandins demonstrate similar in vitro and in vivo activity against Aspergillus sp, but only caspofungin is approved for treatment in patients who are intolerant of or refractory to other therapies. Voriconazole and amphotericin B have demonstrated synergy with the echinocandins. The clinical response to combination therapy has been variable; however, the mortality rate appears to be lower with combination therapy than monotherapy. Large controlled trials are needed to determine the role of combination therapy for invasive aspergillosis. Micafungin and anidulafungin generally have a lower frequency of adverse reactions compared with caspofungin. Phlebitis (3.5-25% of patients) and elevated liver enzyme levels (1-15%) occur more often with caspofungin compared with micafungin and anidulafungin (< 8%). Overall, the three echinocandins are relatively safe and effective agents for the treatment of Candida infections.

Breakthrough zygomycosis after voriconazole administration among patients with hematologic malignancies who receive hematopoietic stem-cell transplants or intensive chemotherapy

Zygomycosis is increasingly reported as a cause of life-threatening fungal infections. A higher proportion of cases reported over the last decades have been in cancer patients, with or without hematopoietic stem cell transplantation (HSCT). The new anti-fungal agent voriconazole is a recently identified risk factor for developing zygomycosis. We reviewed the clinical characteristics and outcomes of a large cohort of cancer patients who developed zygomycosis after exposure to voriconazole. Health care professionals at 13 large cancer centers provided clinical information on cancer patients with zygomycosis and prior exposure to voriconazole. Criteria for inclusion were 5 days or more of voriconazole use and diagnostic confirmation with tissue or histology. Fifty-eight cases were identified among patients with hematologic malignancies, 62% including patients who underwent a HSCT procedure. Fifty-six patients received voriconazole for primary or secondary prophylaxis against fungal infection. In addition to prior exposure to voriconazole, patients also had several of the previously established risk factors for zygomycosis. Amphotericin B was the most commonly prescribed anti-fungal therapy. Overall mortality was 73%. We conclude that zygomycosis after exposure to voriconazole is a recently described entity that is frequently fatal, despite treatment with currently available anti-fungal agents and surgery.