Primary Therapy Of Invasive Aspergillosis Research Articles

Comparing the Real-World Use of Isavuconazole to Other Anti-Fungal Therapy for Invasive Fungal Infections in Patients with and without Underlying Disparities: A Multi-Center Retrospective Study

Invasive fungal infections (IFIs) are a major cause of morbidity and mortality among immunocompromised patients with underlying malignancies and prior transplants. FDA approved Isavuconazole as a primary therapy for Invasive Aspergillosis (IA) and Mucormycosis. This study aims to compare the real-world clinical outcomes and safety of isavuconazole to voriconazole and an amphotericin B-based regimen in patients with underlying malignancies and a transplant. In addition, the response to anti-fungal therapy and the outcome were compared among patients with a disparity (elderly, obese patients, patients with renal insufficiency and diabetes mellitus) versus those with no disparity. We performed a multicenter retrospective study, including patients with cancer diagnosed with an invasive fungal infection, and treated primarily with isavuconazole, voriconazole or amphotericin B. Clinical, radiologic findings, response to therapy and therapy related adverse events were evaluated during 12 weeks of follow-up. We included 112 patients aged 14 to 77 years, and most of the IFIs were classified into definite (29) or probable (51). Most cases were invasive aspergillosis (79%), followed by fusariosis (8%). Amphotericin B were used more frequently as primary therapy (38%) than isavuconazole (30%) or voriconazole (31%). Twenty one percent of the patients presented adverse events related to primary therapy, with patients receiving isavuconazole presenting less adverse events when compared to voriconazole and amphotericin (p < 0.001; p = 0.019). Favorable response to primary therapy during 12 weeks of follow-up were similar when comparing amphotericin B, isavuconazole or voriconazole use. By univariate analysis, the overall cause of mortality at 12 weeks was higher in patients receiving amphotericin B as primary therapy. However, by multivariate analysis, Fusarium infection, invasive pulmonary infection or sinus infection were the only independent risk factors associated with mortality. In the treatment of IFI for patients with underlying malignancy or a transplant, Isavuconazole was associated with the best safety profile compared to voriconazole or amphotericin B-based regimen. Regardless of the type of anti-fungal therapy used, invasive Fusarium infections and invasive pulmonary or sinus infections were the only risk factors associated with poor outcomes. Disparity criteria did not affect the response to anti-fungal therapy and overall outcome, including mortality.

Real-World Use of Isavuconazole as Primary Therapy for Invasive Fungal Infections in High-Risk Patients with Hematologic Malignancy or Stem Cell Transplant.

(1) Introduction: Invasive fungal infections (IFIs) are a major cause of morbidity and mortality among immunocompromised patients with hematologic malignancies (HM) and stem cell transplants (SCT). Isavuconazole was approved by FDA as a primary therapy for Invasive Aspergillosis (IA) and Mucormycosis. The aim of this study is to look at the real-world use of Isavuconazole in patients with HM and evaluate their clinical outcomes and safety. (2) Methods: We conducted a retrospective study of HM patients at MD Anderson Cancer Center who had definite, probable or possible mold infections between 1 April 2016 and 31 January 2020 and were treated with Isavuconazole for a period of at least 7 days. Clinical and radiological findings were assessed at baseline and at 6 and 12 weeks of follow up. (3) Results: We included 200 HM patients with IFIs that were classified as definite (11), probable (63) and possible (126). Aspergillus spp was the most commonly isolated pathogen. The majority of patients (59%) received prophylaxis with anti-mold therapy and Isavuconazole was used as a primary therapy in 43% of patients, and as salvage therapy in 58%. The switch to Isavuconazole was driven by the failure of the primary therapy in 66% of the cases and by adverse effects in 29%. Isavuconazole was used as monotherapy in 30% of the cases and in combination in 70%. Adverse events possibly related to Isavuconazole were reported in eight patients (4%) leading to drug discontinuation. Moreover, a favorable response with Isavuconazole was observed in 40% at 6 weeks and in 60% at 12 weeks. There was no significant difference between isavuconazole monotherapy and combination therapy (p = 0.16 at 6 weeks and p = 0.06 at 12 weeks). Finally, there was no significant difference in outcome when Isavuconazole was used after failure of other anti-mold prophylaxis or treatment versus when used de novo as an anti-mold therapy (p = 0.68 at 6 weeks and p = 0.25 at 12 weeks). (4) Conclusions: Whether used as first-line therapy or after the failure of other azole and non-azole prophylaxis or therapies, isavuconazole seems to have a promising clinical response and a good safety profile as an antifungal therapy in high-risk cancer patients with hematologic malignancies. Moreover, combination therapy did not improve the outcome compared to Isavuconazole therapy.

Diagnosis and Treatment of Invasive Mold Diseases.

Although invasive fungal diseases are relatively less common than superficial diseases, there has been an overall increase in their incidence. Here, I review the epidemiology, diagnosis, and treatment of invasive mold diseases (IMDs) such as aspergillosis, mucormycosis, hyalohyphomycosis, and phaeohyphomycosis. Histopathologic demonstration of tissue invasion by hyphae or recovery of mold by the culture of a specimen obtained by a sterile procedure provides definitive evidence of IMD. If IMD cannot be confirmed through invasive procedures, IMD can be diagnosed through clinical criteria such as the European Organization for Research and Treatment of Cancer/Invasive Fungal Infections Cooperative Group and the National Instituteof Allergy and Infectious Diseases Mycoses Study Group (EORTC/MSG) definitions. For initial primary therapy of invasive aspergillosis, voriconazole or isavuconazole is recommended and lipid formulations of amphotericin B are useful primary alternatives. Echinocandins are representative antifungal agents for salvage therapy. Treatment of invasive mucormycosis involves a combination of urgent surgical debridement of involved tissues and antifungal therapy. Lipid formulations of amphotericin B are the drug of choice for initial therapy. Isavuconazole or posaconazole can be used as salvage or step-down therapy. IMDs other than aspergillosis and mucormycosis include hyalohyphomycosis and phaeohyphomycosis, for which there is no standard therapy and the treatment depends on the clinical disease and status of the patient.

Comparative Pharmacodynamics of Echinocandins against Aspergillus fumigatus Using an In Vitro Pharmacokinetic/Pharmacodynamic Model That Correlates with Clinical Response to Caspofungin Therapy: Is There a Place for Dose Optimization?

Echinocandins have been used as primary therapy of invasive aspergillosis (IA), with suboptimal results at standard dosing. Here, we explored the efficacy of dose escalation in a validated in vitro pharmacokinetic/pharmacodynamic (PK/PD) model. Six echinocandin wild-type (WT) and three non-WT A. fumigatus isolates were tested in an in vitro PK/PD model simulating anidulafungin, caspofungin, and micafungin exposures with a free drug maximum concentration (fCmax) of 0.01 to 16 mg/liter and a half-life (t1/2) of 8 to 22 h. The relationship between the area under the dosing interval time-free drug concentration curve (fAUC0-24)/minimum effective concentration (MEC) and % aberrant mycelium formation was analyzed. PK/PD indices associated with 50 to 99.99% maximal activity (EI50 to EI99.99) were correlated with the clinical outcome of a 50-mg/day standard dose of caspofungin. The probability of target attainment (PTA) was calculated for different dosing regimens of each echinocandin via Monte Carlo analysis. A sigmoidal PK/PD relationship was found for WT isolates with EI99 values of 766, 8.8, and 115 fAUC0-24/CLSI MEC for anidulafungin, caspofungin, and micafungin, respectively. No aberrant mycelia were observed for non-WT isolates, irrespective of their MEC and drug exposure. The EI99, EI99.9, and EI99.99 values corresponded to 2-, 3-, and 4-log10 formation of aberrant mycelia and correlated with survival, favorable, and complete response rates to caspofungin primary therapy in patients with IA. A very low PTA (<13%) was found for the standard doses of all echinocandins, whereas a PTA of ≥90% was found with 100 and 150 mg/day of caspofungin and 1,400 mg/day micafungin against WT isolates. For anidulafungin, the PTA for 1,500 mg/day was 10%. Among the three echinocandins, only caspofungin at 2 or 3 times the licensed dosing was associated with a high PTA. Caspofungin dose escalation might deserve clinical validation.

1182. The Real-World Use of Isavuconazole as Primary or salvage Therapy of Invasive Fungal infections in High-Risk Patients with Hematologic Malignancy or Stem Cell Transplant

BackgroundInvasive fungal infections (IFIs) are a major cause of morbidity and mortality among immunocompromised patients with hematologic malignancies (HM) and stem cell transplants (SCT). Isavuconazole was approved by FDA as a primary therapy for Invasive Aspergillosis (IA) and Mucormycosis. The aim of this study is to look at the real-world use of Isavuconazole in patients with HM and evaluate their clinical outcomes and safety.MethodsWe conducted a retrospective study of 200 HM patients at MD Anderson Cancer Center who had definite, probable or possible mold infections between April 2016 and January 2020 and were treated with Isavuconazole for a period of at least 7 days. Clinical and radiological findings were assessed at baseline and at 6 and 12 weeks of follow up.ResultsHM patients with IFIs were classified as definite (11), probable (66) and possible (123). IA was the most commonly isolated pathogen followed by mucor and candida. The majority of patients (65%) received prophylaxis with anti-mold therapy, 73% consisted of azoles and 22% of echinocandins. Isavuconazole was used as a primary therapy in 57.5% of patients, and as salvage therapy in 42.5%. The switch to Isavuconazole was driven by failure of the primary therapy in 50% of the cases and by adverse effects in 28%. These included elevated liver function tests (LFTs), subtherapeutic voriconazole levels and prolonged QT. Isavuconazole was used as monotherapy in 30% of the cases and combination in 70% mostly with a polyene (54%) and/or an echinocandin (27%). A favorable response with Isavuconazole was observed in 57% at 6 weeks of therapy. Adverse events possibly related to Isavuconazole were reported in 6 patients (3%) leading to drug discontinuation. These included 5 elevated transaminases and 1 nausea. All-cause mortality was reported in 46% of patients and IFI-attributable mortality in 25%.ConclusionSelecting Isavuconazole therapy was mainly driven by failure of other antifungal agents or adverse events to other antifungals such as increased LFTs, subtherapeutic voriconazole levels or prolonged QT. Isavuconazole seems to have a promising clinical response and a good safety profile as an antifungal therapy in high risk cancer patients with HM.Disclosures Issam I. Raad, MD, Citius (Other Financial or Material Support, Ownership interest)Cook Medical (Grant/Research Support)Inventive Protocol (Other Financial or Material Support, Ownership interest)Novel Anti-Infective Technologies (Shareholder, Other Financial or Material Support, Ownership interest)

Successful Treatment of Allergic Bronchopulmonary Aspergillosis With Isavuconazole: Case Report and Review of the Literature.

Isavuconazole is a new triazole that is approved for primary therapy of invasive aspergillosis. We provide the first report of a patient with allergic bronchopulmonary aspergillosis (ABPA) who was successfully treated with isavuconazole with marked improvement and minimal adverse effects. We further review the literature on antifungal management of ABPA.

Cost-effectiveness analysis of combination antifungal therapy with voriconazole and anidulafungin versus voriconazole monotherapy for primary treatment of invasive aspergillosis in Spain

ObjectiveAccording to a recent randomized, double-blind clinical trial comparing the combination of voriconazole and anidulafungin (VOR+ANI) with VOR monotherapy for invasive aspergillosis (IA) in patients with hematologic disease or with hematopoietic stem cell transplant, mortality was lower after 6 weeks with VOR+ANI than with VOR monotherapy in a post hoc analysis of patients with galactomannan-based IA. The objective of this study was to compare the cost-effectiveness of VOR+ANI with VOR, from the perspective of hospitals in the Spanish National Health System.MethodsAn economic model with deterministic and probabilistic analyses was used to determine costs per life-year gained (LYG) for VOR+ANI versus VOR in patients with galactomannan-based IA. Mortality, adverse event rates, and life expectancy were obtained from clinical trial data. The costs (in 2015 euros [€]) of the drugs and the adverse event-related costs were obtained from Spanish sources. A Tornado plot and a Monte Carlo simulation (1,000 iterations) were used to assess uncertainty of all model variables.ResultsAccording to the deterministic analysis, for each patient treated with VOR+ANI compared with VOR monotherapy, there would be a total of 0.348 LYG (2.529 vs 2.181 years, respectively) at an incremental cost of €5,493 (€17,902 vs €12,409, respectively). Consequently, the additional cost per LYG with VOR+ANI compared with VOR would be €15,785. Deterministic sensitivity analyses confirmed the robustness of these findings. In the probabilistic analysis, the cost per LYG with VOR+ANI was €15,774 (95% confidence interval: €15,763–16,692). The probability of VOR+ANI being cost-effective compared with VOR was estimated at 82.5% and 91.9%, based on local cost-effectiveness thresholds of €30,000 and €45,000, respectively.ConclusionAccording to the present economic study, combination therapy with VOR+ANI is cost-effective as primary therapy of IA in galactomannan-positive patients in Spain who have hematologic disease or hematopoietic stem cell transplant, compared with VOR monotherapy.

Ibrutinib—a new standard treatment for relapsed mantle cell lymphoma?

728 www.thelancet.com Vol 387 February 20, 2016 In The Lancet, Martin Dreyling and colleagues present the results of a large, international, randomised phase 3 trial comparing the only two drugs approved for previously treated mantle cell lymphoma in Europe: temsirolimus and ibrutinib. Among 280 patients, those randomly assigned to daily oral ibrutinib 560 mg (n=139) showed a signifi cant improvement in progression-free survival, the trial’s primary endpoint, compared with patients (n=141) assigned to daily intravenous temsirolimus 175 mg (14·6 months vs 6·2 months; hazard ratio 0·43 [95% CI 0·32–0·58]). Ibrutinib was also better tolerated than temsirolimus, with fewer study discontinuations because of adverse events. Therefore, the results from this trial clearly establish ibrutinib as a new standard for treatment of relapsed mantle cell lymphoma. Representing only 5% of all non-Hodgkin lymphomas, mantle cell lymphoma is not the most epidemiologically relevant disease. Its natural history and poor prognosis, however, have garnered substantial attention. After an initial chemotherapy-induced remission of varying duration, patients with mantle cell lymphoma generally undergo a series of subsequent therapies, with successes measured in months as the disease and treatment-related side-eff ects slowly take their toll. A constant unmet need, mantle cell lymphoma has been a model for the accelerated development of novel targeted drugs. The US Food and Drug Administration (FDA) approved bortezomib and lenalidomide for patients with mantle cell lymphoma who had received previous treatments, on the basis of results from phase 2 trials that showed an overall response rate of about 30% and equally high occurrences of study discontinuation because of adverse events. The development of temsirolimus was less straightforward. Results from two clinical trials showed that temsirolimus possessed substantial activity against mantle cell lymphoma (with overall response rates of about 40%), but also a therapeutic index that favoured lower doses. An international phase 3 trial compared two doses of temsirolimus against investigator’s choice of treatment (a variety of single chemotherapy drugs), and showed that 22% of patients receiving higher-dose temsirolimus (175 mg per week for 3 weeks followed by 75 mg per week thereafter) achieved an objective response, with a median progression-free survival of 4·8 months, compared with investigator’s choice (2% and 1·9 months, respectively). 22% of patients receiving the higher dose of temsirolimus discontinued treatment because of an adverse event, compared with 11% of patients receiving the investigator’s choice who discontinued for the same reason. These results were suffi cient for approval of temsirolimus for the treatment of mantle cell lymphoma by the European Medicines Agency (EMA) in 2008, but not by the FDA. In 2009, the fi rst-in-class, oral, small molecule inhibitor of Bruton’s tyrosine kinase, ibrutinib, entered clinical development. On the basis of promising results in seven of nine patients with mantle cell lymphoma treated in a phase 1 trial, a non-pivotal, phase 2 trial (PCYC-1104) was designed with the intention of better Ibrutinib—a new standard treatment for relapsed mantle cell lymphoma? 4 Marr KA, Schlamm HT, Herbrecht R, et al. Combination antifungal therapy for invasive aspergillosis: a randomized trial. Ann Intern Med 2015; 162: 81–89. 5 Miceli MH, Kauff man CA. Isavuconazole: a new broad-spectrum triazole antifungal agent. Clin Infect Dis 2015; 61: 1558–65. 6 Teusink A, Vinks AA, Zhang K, et al. Genotype-directed dosing leads to optimized voriconazole levels in pediatric patients receiving hematopoietic stem cell transplantation. Biol Blood Marrow Transplant 2015; published oline Nov 23. DOI:10.1016/j.bbmt.2015.11.011. 7 Lutsar I, Hodges MR, Tomaszewski K, Troke PF, Wood ND. Safety of voriconazole and dose individualization. Clin Infect Dis 2003; 36: 1087–88. 8 Ashbee HR, Barnes RA, Johnson EM, Richardson MD, Gorton R, Hope WW. Therapeutic drug monitoring (TDM) of antifungal agents: guidelines from the British Society for Medical Mycology. J Antimicrob Chemother 2014; 69: 1162–76. 9 Ananda-Rajah MR, Cheng A, Morrissey CO, et al. Attributable hospital cost and antifungal treatment of invasive fungal diseases in high-risk hematology patients: an economic modeling approach. Antimicrob Agents Chemother 2011; 55: 1953–60. 10 Munoz P, Valerio M, Vena A, Bouza E. Antifungal stewardship in daily practice and health economic implications. Mycoses 2015; 58 (suppl 2): 14–25. 11 Ananda-Rajah MR, Slavin MA, Thursky KT. The case for antifungal stewardship. Curr Opin Infect Dis 2012; 25: 107–15. 12 Herbrecht R, Denning DW, Patterson TF, et al. Voriconazole versus amphotericin B for primary therapy of invasive aspergillosis. N Engl J Med 2002; 347: 408–15.

Cost Analysis of Voriconazole Versus Liposomal Amphotericin B for Primary Therapy of Invasive Aspergillosis among High-Risk Hematologic Cancer Patients in Brazil

Cost Analysis of Voriconazole Versus Liposomal Amphotericin B for Primary Therapy of Invasive Aspergillosis among High-Risk Hematologic Cancer Patients in Brazil

PSY22 - Cost analysis of Voriconazole versus Caspofungin for Primary Therapy of invasive Aspergillosis among High-Risk Hematologic Cancer Patients in China

PSY22 - Cost analysis of Voriconazole versus Caspofungin for Primary Therapy of invasive Aspergillosis among High-Risk Hematologic Cancer Patients in China

Cost analysis of voriconazole versus liposomal amphotericin B for primary therapy of invasive aspergillosis among patients with haematological disorders in Germany and Spain.

BackgroundThe current healthcare climate demands pharmacoeconomic evaluations for different treatment strategies incorporating drug acquisition costs, costs incurred for hospitalisation, drug administration and preparation, diagnostic and laboratory testing and drug-related adverse events (AEs). Here we evaluate the pharmacoeconomics of voriconazole versus liposomal amphotericin B as first-line therapies for invasive aspergillosis (IA) in patients with haematological malignancy and prolonged neutropenia or who were undergoing haematopoietic stem-cell transplantation in Germany or Spain.MethodsA decision analytic model based on a decision tree was constructed to estimate the potential treatment costs of voriconazole versus liposomal amphotericin B. Each model pathway was defined by the probability of an event occurring and the costs of clinical outcomes. Outcome probabilities and cost inputs were derived from the published literature, clinical trials, expert panels and local database costs. In the base case, patients who failed to respond to first-line therapy were assumed to experience a single switch between comparator drugs or the other drug was added as second-line treatment. Base-case evaluation included only drug-management costs and additional hospitalisation costs due to severe AEs associated with first- and second-line therapies. Sensitivity analyses were conducted to assess the robustness of the results. Cost estimates were inflated to 2011 euros (€).ResultsBased on clinical trial success rates of 52.8% (voriconazole) and 50.0% (liposomal amphotericin B), voriconazole had lower total treatment costs compared with liposomal amphotericin B in both Germany (€12,256 versus €18,133; length of therapy [LOT] = 10-day intravenous [IV] + 5-day oral voriconazole and 15-day IV liposomal amphotericin B) and Spain (€8,032 versus €10,516; LOT = 7-day IV + 8-day oral voriconazole and 15-day IV liposomal amphotericin B). Assuming the same efficacy (50.0%) in first-line therapy, voriconazole maintained a lower total treatment cost compared with liposomal amphotericin B. Cost savings were primarily due to the lower drug acquisition costs and shorter IV LOT associated with voriconazole. Sensitivity analyses showed that the results were sensitive to drug price, particularly the cost of liposomal amphotericin B.ConclusionsVoriconazole is likely to be cost-saving compared with liposomal amphotericin B when used as a first-line treatment for IA in Germany and Spain.

Aspergillosis in Solid Organ Transplantation

Invasive aspergillosis (IA) occurs in 1–15% of the solid organ transplant (SOT) recipients. Mortality rate in transplant recipients with IA historically has ranged from 65% to 92% (1–4). However, currently reported mortality rate in IA among SOT recipients is 22% (5). An estimated 9.3– 16.9% of all deaths in transplant recipients in the first year have been considered attributable to IA (6). Although the outcomes have improved in the current era, IA remains a significant posttransplant complication in SOT recipients. The review herein discusses the epidemiologic characteristics, risk factors, diagnostic laboratory assays and the approach to antifungal prophylaxis and treatment of IA in SOT recipients.

PIN27 Cost Analysis of Voriconazole Versus Liposomal Amphotericin B for Primary Therapy of Invasive Aspergillosis Among Hematologic Patients in Germany

PIN27 Cost Analysis of Voriconazole Versus Liposomal Amphotericin B for Primary Therapy of Invasive Aspergillosis Among Hematologic Patients in Germany

Steady-State Plasma Pharmacokinetics of Oral Voriconazole in Obese Adults

Voriconazole is an antifungal agent that is currently used as primary therapy for invasive aspergillosis and as a potential treatment for systemic candidiasis. Data on the dosing of voriconazole in obese patients are not available, which is problematic given the increased prevalence of this special population. To address this limitation, we evaluated the steady-state plasma pharmacokinetics of voriconazole through a two-way, crossover design in a cohort of eight healthy volunteers with class II obesity or greater. The median (minimum, maximum) age, weight, and body mass index of obese subjects were 43 (22, 48) years, 133 (105, 155) kg, and 46.2 (38.4, 53.7) kg/m², respectively. The geometric mean ratios (90% confidence intervals) for the area under the curve from time zero to 12 h (dosing interval; AUC(0-τ)), maximum concentration (C(max)), minimum concentration at 12 h (C(min)), and time to C(max) (T(max)) of the 300-mg to 200-mg dosing regimens were 2.0 (1.5, 2.7), 1.8 (1.4, 2.2), 2.2 (1.6, 2.9), and 1.6 (1.0, 2.4) in obese subjects, respectively. The AUC(0-τ) values observed in obese subjects were comparable to those from a historical data set of nonobese subjects. Voriconazole dose-normalized AUC(0-τ) values had a modestly better correlation with lean body weight (r² = 0.42) than total body weight (r² = 0.14). An excellent linear relationship (r² = 0.96) was identified between C(min) values and AUC(0-τ) values. Adjustment of voriconazole doses in individuals with class II obesity or greater does not appear to be necessary on the basis of body weight.

Echinocandin Antifungal Drugs in Fungal Infections

This review compares the pharmacology, spectrum of antifungal activity, pharmacokinetic and pharmacodynamic properties, safety and clinical efficacy of the three licensed echinocandins: caspofungin, micafungin and anidulafungin. Echinocandins inhibit the synthesis of 1,3-β-D-glucan, an essential component of the fungal cell wall, and represent a valuable treatment option for fungal infections. The echinocandins exhibit potent in vitro and in vivo fungicidal activity against Candida species, including azole-resistant pathogens. For all agents, strains with drug minimum inhibitory concentrations (MICs) of ≤ 2 μg/mL are considered susceptible; the MIC at which 90% of isolates tested were inhibited (MIC₉₀) values are typically <2 μg/mL but 100-fold higher MIC₉₀ values are seen with Candida parapsilosis (1-2 μg/mL) and Candida guilliermondii (1-4 μg/mL). Activity is comparable between the three agents, although limited data indicate that anidulafungin may have low MICs against C. parapsilosis and Candida glabrata strains that demonstrate elevated MICs to caspofungin and micafungin. All three drugs have good fungistatic activity against Aspergillus spp., although minimal effective concentrations of micafungin and anidulfungin are 2- to 10-fold lower than those for caspofungin. Synergistic/additive in vitro effects of echinocandins when combined with a polyene or azole have been observed. Clinical resistance to the echinocandins is rare despite case reports of caspofungin resistance in several Candida spp. Resistance has been attributed to mutations in the FKS1 gene within two hot spot regions, leading to amino acid substitutions, mostly at position 645 (serine), yet not all FKS1 mutants have caspofungin MICs of >2 μg/mL. Of the three echinocandins, the in vitro 'paradoxical effect' (increased growth at supra-MIC drug concentrations) is observed least often with anidulafungin. All echinocandins have low oral bioavailability, and distribute well into tissues, but poorly into the CNS and eye. Anidulafungin is unique in that it undergoes elimination by chemical degradation in bile rather than via hepatic metabolism, has a lower maximum concentration and smaller steady state under the concentration-time curve but longer half-life than caspofungin or micafungin. In children, dosing should be based on body surface area. Daily doses of caspofungin (but not micafungin and anidulafungin) should be decreased (from 50 to 35 mg) in moderate liver insufficiency. All echinocandins display concentration-dependent fungicidal (for Candida) or fungistatic (for Aspergillus) activity. The postantifungal effect is 0.9-20 hours against Candida and <0.5 hours against Aspergillus. The echinocandins are well tolerated with few serious drug-drug interactions since they are not appreciable substrates, inhibitors or inducers of the cytochrome P450 or P-glycoprotein systems. In parallel with the greater clinical experience with caspofungin, this agent has a slightly higher potential for adverse effects/drug-drug interactions, with the least potential observed for anidulafungin. Caspofungin (but not micafungin or anidulafungin) dosing should be increased if coadministered with rifampicin and there are modest interactions of caspofungin with calcineurin inhibitors. All three agents are approved for the treatment of oesophageal candidiasis, candidaemia and other select forms of invasive candidiasis. Only micafungin is licensed for antifungal prophylaxis in stem cell transplantation, whereas caspofungin is approved for empirical therapy of febrile neutropenia. Caspofungin has been evaluated in the salvage and primary therapy of invasive aspergillosis. Combination regimens incorporating an echinocandin showing promise in the treatment of aspergillosis. However, echinocandins remain expensive to use.

Pulmonary aspergillosis: clinical presentation, diagnostic tests, management and complications

When functioning properly, the immune system recognizes inhaled fungi and controls their growth, while avoiding injurious inflammation and allergy. 'Aspergillosis' represents a spectrum of clinical diseases resulting from impaired or excessive immune responses. Invasive aspergillosis is principally disease of severely immunocompromised patients, whereas allergic forms of aspergillosis result from an excessive inflammatory response to hyphae colonizing the sinopulmonary tract. We will review insights gained in host defense against Aspergillus species and the immunopathogenesis of Aspergillus-related diseases as well as important advances made in fungal diagnostics and antifungal therapy. Important advances have been made in diagnosis of invasive aspergillosis and in antifungal agents. Voriconazole was superior to amphotericin B deoxycholate as primary therapy for invasive aspergillosis. There is significant interest in combination antifungal therapy for invasive aspergillosis. Fungal genomics offers a powerful opportunity to gain knowledge about fungal virulence factors that can be targets for drug development. In addition, new insights have been gained regarding host defense against Aspergillus species that may be exploited therapeutically. We have gained substantial knowledge regarding how the immune system recognizes inhaled fungi and calibrates the inflammatory response. There has also been substantial progress in tools to diagnose aspergillosis and in antifungal therapeutics. Future progress will likely involve the development of more refined diagnostic tools, new classes of antifungal agents, and greater knowledge of pathogen and host factors that predispose to aspergillosis.

Invasive Aspergillosis in Solid Organ Transplant Recipients

This chapter discusses the current status and evolving trends in the epidemiology, risk factors, diagnostic laboratory assays, and the approach to antifungal prophylaxis and treatment of invasive aspergillosis in Solid Organ Transplant (SOT) recipients. Most invasive fungal infections in these high-risk patients occur within the first month posttransplant; the median time to onset of invasive aspergillosis after renal replacement therapy and retransplantation was 13 and 28 days, respectively, in one study. Other factors associated with invasive aspergillosis in liver transplant recipients include transplantation for fulminate hepatic failure, cytomegalovirus (CMV) infection, and prolonged intensive care unit stay. A retrospective survey documented invasive pulmonary aspergillosis in 7.5% (19/251) of lung transplant recipients, of whom 47% (9/19) had disseminated aspergillosis. In a survey of antifungal prophylactic strategies in lung transplant units in the United States, aerosolized amphotericin B was the most frequently employed antifungal prophylactic agent. In order of preference, the prophylactic agents used in lung transplant centers in this study were inhaled amphotericin B (61%), itraconazole (46%), parenteral amphotericin formulations (25%), and fluconazole (21%); many centers used more than one agent. Preemptive therapy, where antifungal prophylaxis is directed towards lung transplant recipients colonized with Aspergillus spp. immediately before or within 6 to 9 months after transplantation, is another approach to the prevention of invasive aspergillosis in lung transplant recipients.

Antifungal Therapy for Invasive Fungal Diseases in Allogeneic Stem Cell Transplant Recipients: An Update

Invasive fungal diseases (IFDs) remain a major cause of morbidity and mortality in allogeneic stem cell transplant (SCT) recipients. While the most common pathogens are Candida spp. and Aspergillus spp., the incidence of infections caused by non-albicans Candida species as well as molds such as Zygomycetes has increased. For many years, amphotericin B deoxycholate (AMB-D) was the only available antifungal for the treatment of IFDs. Within the past decade, there has been a surge of new antifungal agents developed and added to the therapeutic armamentarium. Lipid-based formulations of amphotericin B provide an effective and less nephrotoxic alternative to AMB-D. Voriconazole has now replaced AMB-D as first choice for primary therapy of invasive aspergillosis (IA). Another extended-spectrum triazole, posaconazole, also appears to be a promising agent in the management of zygomycosis, refractory aspergillosis, and for prophylaxis. Members of the newest antifungal class, the echinocandins, are attractive agents in select infections due to their safety profile, and are a more attractive option compared to AMB-D as initial treatment for invasive candidiasis and (based on one study) challenge fluconazole for superiority in management with this mycoses. However, challenges do exist among these newer agents in very high-risk individuals like allogeneic SCT recipients, which may include adverse drug events, drug-drug interactions, variability in oral absorption, and availability of alternative formulations. The addition of newer agents has also stimulated interest in the potential application of combination therapy in serious, life-threatening infections. However, adequate studies are not available for most IFDs; thus, the clinical use of combination therapy is not evidenced based on most cases and preciseness in its use is uncertain. Finally, therapeutic drug monitoring of select antifungals (notably posaconazole and voriconazole) may play an increasing role due to significant interpatient variability in serum concentrations after standard doses.

Antifungal Management Practices in Liver Transplant Recipients

We sought to determine the approach to antifungal prophylaxis, and diagnostic and therapeutic practices for the management of invasive aspergillosis in liver transplant recipients. Data were collected by an electronic survey questionnaire sent to all active liver transplant programs in North America; 63% (67/106) of the sites completed the survey. Overall, 91% of the sites employed antifungal prophylaxis; 28% used universal prophylaxis and 72% targeted it toward high-risk patients. Fluconazole was the most commonly used agent for universal and targeted prophylaxis. The leading choice for mold-active agents for antifungal prophylaxis was the echinocandins. Combination therapy was used as primary therapy for invasive aspergillosis in 47%, and as salvage in 80%. Thus, a vast majority of the surveyed programs employ antifungal prophylaxis and most use targeted prophylaxis. Consideration of these practices could guide clinical trial design to optimize antifungal prophylaxis in these patients. Our findings also merit investigations to better define the role of diagnostic assays and combination therapeutic strategies for invasive aspergillosis in liver transplant recipients.

Combination antifungal therapy: what can and should we expect?

Invasive fungal infections are associated with significant morbidity and mortality among immunocompromised patients. Recent advances in antifungal development have afforded us more pharmacologic compounds to choose from when managing these fungal infections. The role of combination antifungal therapy has been well established for fungal infections such as cryptococcal meningitis. The availability of new antifungals, increased incidence of mould infections and high mortality among certain affected populations, such as hematopoietic stem cell transplant recipients, has stimulated interest in the clinical use of combination antifungal therapy. In this paper, we review supporting evidence for the use of combination antifungals in the treatment of cryptococcal meningitis, invasive candidiasis, invasive aspergillosis and zygomycosis. Several controlled clinical trials have demonstrated benefits of combination antifungal approaches for patients with cryptococcal meningitis and invasive candidiasis, but variable effects when using different agents in combination have been reported. Randomized prospective studies of combination antifungal therapy in mould infections are lacking but some series provide supportive evidence for this approach. We also describe limitations of the data and these study designs, including the fact that we still need randomized controlled multicenter studies of combination antifungal therapy for mould infections. Trials in this area should be performed with efficiency and economics in mind, and could potentially use surrogate markers as end points. Therefore, we suggest future investigations of combination antifungal therapy should include a randomized, comparative trial of primary therapy for invasive aspergillosis.