Economic evaluation of voriconazole compared with conventional amphotericin B for the primary treatment of aspergillosis in immunocompromised patients

The efficacy and safety of first-line monotherapies in primary therapy of invasive aspergillosis: a systematic review

Objective

Several antifungals are available for the treatment of patients with invasive aspergillosis (IA). This study aims to evaluate the relative efficacy and safety of the first-line monotherapies in primary therapy of IA through network meta-analysis (NMA).

Methods

We systematically searched PubMed, Embase, Web of Science, Cochrane Library, China National Knowledge Infrastructure, VIP database, Wanfang database, and China Biology Medicine for randomized controlled trials (RCTs) up to July 2023 that evaluated the efficacy and safety of monotherapies. We performed NMA with a frequentist random effects model and assessed the certainty of evidence using the GRADE (Grading of Recommendations Assessment, Development and Evaluation) approach. Primary outcomes were the all-cause mortality at week 12, and secondary outcomes included overall response rate, and incidence of adverse events (AEs) and severe adverse events (SAEs).

Results

A total of three RCTs involving 1,368 participants (four antifungals) were included. The NMA showed that compared to amphotericin B deoxycholate (D-AmB), the triazoles (posaconazole (POS), isavuconazole (ISA) and voriconazole (VCZ)) can improve the overall response rate in primary therapy of IA, but only VCZ and ISA can reduce the all-cause mortality at week 12 for patients with proven and probable IA (VCZ vs D-AmB: RR = 0.66, 95%CI = 0.47-0.93, moderate certainty; ISA vs D-AmB: RR = 0.52, 95%CI = 0 .31-0.86, low certainty). ISA (SUCRA = 93.50%; mean rank, 1.20) seemed to be the most effective therapy in the above population. As to proven, probable, and possible IA patients, the triazoles were superior to D-AmB in terms of reducing all-cause mortality. Furthermore, the risk of AEs and SAEs was comparable for the three triazoles, but the risk of SAEs was significantly higher for D-AmB than others.

Conclusion

The efficacy and safety of triazoles are more favorable than D-AmB in the primary therapy of IA, with ISA being the optimal choice.

Systematic Review Registration

PROSPERO CRD42023407632.

Budget Impact of Microbial Cell-Free DNA Testing Using the Karius® Test as an Alternative to Invasive Procedures in Immunocompromised Patients with Suspected Invasive Fungal Infections

BACKGROUND

Invasive fungal infection is a major source of morbidity and mortality. The usage of microbial cell-free DNA for the detection and identification of invasive fungal infection has been considered as a potential alternative to invasive procedures allowing for rapid results.

OBJECTIVE

This analysis aimed to assess the budget implications of using the Karius^® Test in patients suspected of invasive fungal infection in an average state in the USA from a healthcare payer perspective.

METHODS

The analysis used a decision tree to capture key stages of the patient pathway, from suspected invasive fungal infection to either receiving treatment for invasive fungal infection or being confirmed as having no invasive fungal infection. The analysis used published costs and resource use from a targeted review of the literature. Because of the paucity of published evidence on the reduction of diagnostic tests displaced by the Karius Test, the analysis used a 50% reduction in the use of bronchoscopy and/or bronchoalveolar lavage. The impact of this reduction was tested in a scenario analysis.

RESULTS

The results of the analysis show that the introduction of the Karius Test is associated with a cost saving of US$2277 per patient; when multiplied by the estimated number of cases per year, the cost saving is US$17,039,666. The scenario analysis showed that the Karius Test only had an incremental cost of US$87 per patient when there was no reduction in bronchoscopy and bronchoalveolar lavage.

CONCLUSIONS

The Karius Test may offer a valuable and timely option for the diagnosis of invasive fungal infection through its non-invasive approach and subsequent cost savings.

Physicochemical stability of voriconazole in elastomeric devices

Objectives

Voriconazole is the drug of choice for invasive aspergillosis (IA), a leading cause of mortality and morbidity in immunocompromised patients. Prolong intravenous administration of voriconazole is often needed in such patients due to high incidence of oral mucositis and unreliable bioavailability of oral dosage form. Administration of voriconazole through elastomeric pump may facilitate early hospital discharge of clinically stable immunocompromised patients needing prolonged intravenous treatment. Therefore, we investigated the physicochemical stability of voriconazole in one of the commonly used elastomeric pumps at three different temperatures for various time points.

Methods

A total of 18 elastomeric pumps were prepared and 6 containing 2 mg/mL of voriconazole (3 in 0.9% sodium chloride and 3 in 5% glucose) were stored at either 4°C for 96 hours, 25°C for 4 hours or at 35°C for 4 hours. An aliquot withdrawn immediately before storage (time 0) and at various time points was analysed for chemical stability using high-performance liquid chromatography and for physical stability using visual, pH and microscopic analyses.

Results

Voriconazole was stable for at least 96 hours, 4 hours and 4 hours at 4°C, 25°C and 35°C, respectively, when admixed with either 0.9% sodium chloride or 5% glucose. No evidence of particle formation, colour change or pH change was observed throughout the study period.

Conclusions

These findings would allow early hospital discharge using elastomeric intravenous administration of voriconazole in patients in whom oral route of administration is not available.

Efficacy and cost-effectiveness of voriconazole prophylaxis for prevention of invasive aspergillosis in high-risk liver transplant recipients

Aspergillus infection remains a significant and deadly complication after liver transplantation (LT). We sought to determine whether the antifungal prophylactic use of voriconazole reduces the incidence of invasive aspergillosis (IA) in high-risk LT recipients without prohibitively increasing cost. During the study era (April 2008 to April 2014), 339 deceased donor LTs were performed. Of those patients, 174 high-risk recipients were administered antifungal prophylaxis with voriconazole. The median biological Model for End-Stage Liver Disease score at the time of LT was 33 (range, 18-49) with 56% requiring continuous renal replacement therapy and 50% requiring ventilatory support immediately before transplantation. Diagnosis of IA was stratified as proven, probable, or possible according to previously published definitions. No IA was documented in patients receiving voriconazole prophylaxis. At 90 days after LT, the institutional cost of prophylaxis was $5324 or 5.6% of the predicted cost associated with post-LT aspergillosis. There was no documentation of resistant strains isolated from any recipient who received voriconazole. In conclusion, these data suggest that voriconazole prophylaxis is safe, clinically effective, and cost-effective in high-risk LT recipients.

Characterization of the FKBP12-Encoding Genes in Aspergillus fumigatus

Invasive aspergillosis, largely caused by Aspergillus fumigatus, is responsible for a growing number of deaths among immunosuppressed patients. Immunosuppressants such as FK506 (tacrolimus) that target calcineurin have shown promise for antifungal drug development. FK506-binding proteins (FKBPs) form a complex with calcineurin in the presence of FK506 (FKBP12-FK506) and inhibit calcineurin activity. Research on FKBPs in fungi is limited, and none of the FKBPs have been previously characterized in A. fumigatus. We identified four orthologous genes of FKBP12, the human FK506 binding partner, in A. fumigatus and designated them fkbp12-1, fkbp12-2, fkbp12-3, and fkbp12-4. Deletional analysis of the four genes revealed that the Δfkbp12-1 strain was resistant to FK506, indicating FKBP12-1 as the key mediator of FK506-binding to calcineurin. The endogenously expressed FKBP12-1-EGFP fusion protein localized to the cytoplasm and nuclei under normal growth conditions but also to the hyphal septa following FK506 treatment, revealing its interaction with calcineurin. The FKBP12-1-EGFP fusion protein didn’t localize at the septa in the presence of FK506 in the cnaA deletion background, confirming its interaction with calcineurin. Testing of all deletion strains in the Galleria mellonella model of aspergillosis suggested that these proteins don’t play an important role in virulence. While the Δfkbp12-2 and Δfkbp12-3 strains didn’t show any discernable phenotype, the Δfkbp12-4 strain displayed slight growth defect under normal growth conditions and inhibition of the caspofungin-mediated “paradoxical growth effect” at higher concentrations of the antifungal caspofungin. Together, these results indicate that while only FKBP12-1 is the bona fide binding partner of FK506, leading to the inhibition of calcineurin in A. fumigatus, FKBP12-4 may play a role in basal growth and the caspofungin-mediated paradoxical growth response. Exploitation of differences between A. fumigatus FKBP12-1 and human FKBP12 will be critical for the generation of fungal-specific FK506 analogs to inhibit fungal calcineurin and treat invasive fungal disease.

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

Background

The 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.

Methods

A 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 (€).

Results

Based 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.

Conclusions

Voriconazole is likely to be cost-saving compared with liposomal amphotericin B when used as a first-line treatment for IA in Germany and Spain.

Adapting a global cost-effectiveness model to local country requirements: posaconazole case study

BACKGROUND

Many countries have various requirements for local economic analyses to assess the value of a new health technology and/or to secure reimbursement. This study presents a case study of an economic model developed to assess the cost-effectiveness of posaconazole vs standard azole therapy (fluconazole/itraconazole) to prevent invasive fungal infections (IFIs), which was adapted by at least 11 countries.

METHODS

Modeling techniques were used to assess the cost-effectiveness of posaconazole vs fluconazole/itraconazole as IFI prophylaxis in patients with acute myelogenous leukemia or myelodysplastic syndromes and chemotherapy-induced neutropenia. For the core model, the probabilities of experiencing an IFI, IFI-related death, and death from other causes were estimated from clinical trial data. Long-term mortality, drug costs, and IFI treatment costs were obtained from secondary sources. Locally changed parameters were probabilities of long-term death and survival, currency, drug costs, health utility, IFI treatment costs, and discount rate.

RESULTS

Locally adapted cost-effective modeling studies indicate that prophylaxis with posaconazole, compared with fluconazole/itraconazole, prolongs survival, and, in most countries, is cost-saving. In all countries, the model predicted that prophylaxis with posaconazole would be associated with an increase in life-years, with increases ranging from 0.016-0.1 life-year saved. In all countries, use of the model led to posaconazole being approved by the appropriate reimbursement authority.

LIMITATIONS

The study did not have power to detect differences between posaconazole and fluconazole or itraconazole separately. The risk of death after 100 days was assumed to be equal for those who did and did not develop an IFI, and equal probabilities of IFI-related and other death during the trial period were used for both groups.

CONCLUSIONS

A core economic model was successfully adapted locally by several countries. The model showed that posaconazole was cost-saving or cost-effective vs fluconazole/itraconazole and led to positive reimbursement listings.

Cost-effectiveness of posaconazole versus fluconazole or itraconazole in the prevention of invasive fungal infections among high-risk neutropenic patients in Spain

BACKGROUND

We evaluated the cost-effectiveness of posaconazole compared with standard azole therapy (SAT; fluconazole or itraconazole) for the prevention of invasive fungal infections (IFI) and the reduction of overall mortality in high-risk neutropenic patients with acute myelogenous leukaemia (AML) or myelodysplastic syndromes (MDS). The perspective was that of the Spanish National Health Service (NHS).

METHODS

A decision-analytic model, based on a randomised phase III trial, was used to predict IFI avoided, life-years saved (LYS), total costs, and incremental cost-effectiveness ratio (ICER; incremental cost per LYS) over patients' lifetime horizon. Data for the analyses included life expectancy, procedures, and costs associated with IFI and the drugs (in euros at November 2009 values) which were obtained from the published literature and opinions of an expert committee. A probabilistic sensitivity analysis (PAS) was performed.

RESULTS

Posaconazole was associated with fewer IFI (0.05 versus 0.11), increased LYS (2.52 versus 2.43), and significantly lower costs excluding costs of the underlying condition (€6,121 versus €7,928) per patient relative to SAT. There is an 85% probability that posaconazole is a cost-saving strategy compared to SAT and a 97% probability that the ICER for posaconazole relative to SAT is below the cost per LYS threshold of €30,000 currently accepted in Spain.

CONCLUSIONS

Posaconazole is a cost-saving prophylactic strategy (lower costs and greater efficacy) compared with fluconazole or itraconazole in high-risk neutropenic patients.

Cost-effectiveness analysis of anidulafungin versus fluconazole for the treatment of invasive candidiasis

BACKGROUND

Anidulafungin was found to be non-inferior to and possibly more efficacious than fluconazole for treatment of invasive candidiasis (IC) in a major randomized clinical trial (RCT). There are no data comparing the cost-effectiveness between azoles and echinocandins in treating IC. This economic analysis investigated the cost-effectiveness of anidulafungin compared with fluconazole for treatment of IC in an Australian setting.

METHODS

A decision analytic model was constructed to capture downstream consequences of using either agent for treatment of IC. The main outcomes analysed in the model were treatment success and treatment failure (observed and indeterminate). Outcome probabilities and treatment pathways were derived from a published RCT. Resources used were estimated by an expert panel and cost inputs were derived from the latest Australian resources. The analysis was based on an Australian hospital perspective. Sensitivity analyses were conducted using Monte Carlo simulation.

RESULTS

Anidulafungin (AU$74,587) had a higher total cost than fluconazole (AU$60,945) per successfully treated patient, primarily due to its higher acquisition cost. Hospitalization was the main cost driver for both comparators. However, when the rates of mortality in both treatment arms were considered, treatment with anidulafungin was expected to save an additional 0.53 life-years, with an incremental cost-effectiveness ratio (ICER) of AU$25 740 per life-years saved, which was below the implicit ICER threshold value for Australia. The results were robust over a wide range of variables.

CONCLUSIONS

This is the first economic evaluation of anidulafungin versus fluconazole in the treatment of IC in Australia. Anidulafungin appears to be a cost-effective option.

Attributable hospital cost and antifungal treatment of invasive fungal diseases in high-risk hematology patients: an economic modeling approach

Studies using patient-level data to determine the attributable cost of invasive fungal diseases (IFDs) are few. Using a case-control study with activity-based costing of patients admitted to a quaternary hospital from 2002 to 2007, we determined attributable hospitalization cost (and 12 weeks thereafter), length of stay (LOS), and costly antifungal treatment (C-AT; liposomal amphotericin B, voriconazole, posaconazole, caspofungin), expressed as defined daily doses (DDDs) per IFD episode, in patients with hematological malignancies and hematopoietic stem cell recipients. Matching criteria and median regression modeling controlled for confounding variables, including LOS prior to IFD onset. Multiple mycoses were identified in 43 matched case-control pairs (n=86). A separate sensitivity analysis included 22 unmatched patients. IFD status was associated with a median excess cost of AU$30,957 (95% confidence interval [CI]=AU$2,368 to AU$59,546; P=0.034), approximating at purchasing power parity US$21,203 (95% CI=US$1,622 to US$40,784) and €15,788 (95% CI=€1,208 to €30,368), increasing to AU$80,291 (95% CI=AU$33,636 to AU$126,946; P=0.001), i.e., US$54,993 (95% CI=US$23,038 to US$86,948) and €40,948 (95% CI=€17,154 to €64,742), with intensive care unit (ICU) requirement. Cost determinants were pharmacy costs (64%; P<0.001) inclusive of antifungal treatment (27%; P<0.001) and ward costs (27%; P=0.091), with proportions persisting through 12 weeks for 25 surviving matched pairs (pharmacy, 60% [P=0.12]; ward, 31% [P=0.21]). Median LOS was not significantly increased unless unmatched patients were included (8 days, 95% CI=1.8 to 14 days; P=0.012). Excess C-ATs were 17 DDDs (95% CI=15 to 19 DDDs; P<0.001) per case patient and 19 DDDs (95% CI=16 to 22 DDDs; P<0.001) per ICU patient. The sensitivity analysis was confirmatory (for median cost, AU$29,441, 95% CI=AU$5,571 to AU$53,310, P=0.016; for C-AT, 17 DDDs, 95% CI=16 to 18 DDDs, P<0.001). IFD results in increased hospital and ICU costs, with pharmacy costs, including antifungal treatment, being major determinants. Consumption of costly antifungal drugs may be a novel resource metric with wider generalizability than cost alone.

Cost effectiveness of posaconazole in the prophylaxis of invasive fungal infections in acute leukaemia patients for the French healthcare system

BACKGROUND

Acute myeloblastic leukaemia (AML) patients are at high risk of suffering from invasive fungal infections (IFI). Posaconazole demonstrated higher efficacy than standard azole agents (SAA) in the prophylaxis of IFI in this population. The authors estimated the cost effectiveness of posaconazole versus SAA in France.

METHODS

A decision-tree model was developed to compare posaconazole with SAA with the results of a published clinical trial. Clinical events were modelled with chance nodes reflecting probabilities of IFI, IFI-related death, and death from other causes. Medical resource consumption and costs were obtained from results of the clinical trial and from a dedicated survey on the costs of treating IFI using a retrospective chart review design.

RESULTS

IFI treatment costs were estimated using medical files from 50 AML patients from six French centres, with a proven and probable IFI, who had been followed-up for 298 days on average. Direct costs directly related to IFI were estimated at €51,033, including extra costs of index hospitalisation, costs of antifungal therapy and additional hospitalisations related to IFI treatment. The model indicated that the healthcare costs for the posaconazole strategy were €5,223 (€2,697 for prophylaxis and €2,526 for IFI management), which was €859 less than the €6,083 in costs with SAA (€469 for prophylaxis and €5614 for IFI management). A sensitivity analysis indicated that there was an 80% probability that prophylaxis using the posaconazole strategy would be superior.

CONCLUSION

The findings from this analysis suggest that posaconazole use is a clinically and economically dominant strategy in the prophylaxis of IFI in AML patients, given the usual limits of economic models and the uncertainty of costs estimates.

Pharmacoeconomics of voriconazole

IMPORTANCE OF THE FIELD

The recent increase in the use of antineoplastic and immune suppressive agents and the use of broad-spectrum antibiotics, prosthetic interventions, organ transplants and more aggressive surgery have been related to a greater prevalence of invasive fungal infections (IFI). Over the past few years, several new antifungal therapies have become available for these patients. Pharmacoeconomic data can play a useful role in comparing the relative benefits of treatment.

AREAS COVERED IN THIS REVIEW

This review summarizes all the available evidence regarding the pharmacoeconomics of voriconazole. A systematic review of pharmacoeconomic analyses through a non-restricted literature search was conducted (until May 2009).

WHAT THE READER WILL GAIN

The reader will gain a greater understanding of the pharmacoeconomics role of voriconazole.

TAKE HOME MESSAGE

The majority of economic analyses have shown that voriconazole is a more cost-effective alternative in the treatment of invasive fungal infections than the antifungal drugs with which it was compared.

Economic evaluation of voriconazole versus caspofungin for the treatment of invasive aspergillosis in Belgium

OBJECTIVE

To perform an economic evaluation of voriconazole versus caspofungin in first line treatment of invasive aspergillosis (IA). These 2 antifungal drugs have a more favorable toxicity profile than the conventional amphotericin B and have a lower cost than the expensive liposomal/lipid formulation of amphotericin B. No head-to-head comparative study was conducted with voriconazole and caspofungin in IA. Based on the clinical trials of both antifungals, a conservative approach of similar efficacy has been considered.

METHODS

The analysis is based on a simplified cost-minimization model with results from the National Health system RIZIV/INAMI perspective (year 2008). Only limited direct costs were considered, namely the drug cost over the episode of treatment.Treatment duration and patients' weight were key parameters. Their values were obtained from the Belgian observational VORIBEL study (Pfizer data on file) for voriconazole treatment. Treatment duration for caspofungin was derived from the EORTC study where almost 50% of the patients were recruited in Belgian centres. Mean cost and incremental cost were calculated. Univariate sensitivity analyses were carried out on weight, treatment duration as well as on route of administration.

RESULTS

In invasive aspergillosis, the weighted cost per episode of fungal infection was 11.996 pound with voriconazole treatment (voriconazole IV followed by oral voriconazole) and 13.657 pound with caspofungin treatment (intravenous caspofungin only). The incremental saving with voriconazole treatment was 1.661 pound per patient.The cost-saving results of voriconazole were confirmed with varying treatment duration within realistic range. 41% of the patients in the VORIBEL study were fully treated with oral formulation. For these patients a saving of 6.375 pound was achieved with the use of oral voriconazole.

CONCLUSION

Voriconazole is a cost-saving option compared with caspofungin in the treatment of invasive aspergillosis.

Economic considerations in the treatment of invasive aspergillosis: a review of voriconazole pharmacoeconomic studies

Invasive aspergillosis is a life-threatening fungal infection predominately affecting immunocompromised individuals. The incidence of inpatient-treated aspergillosis cases in the US is estimated to be between 3.02 and 3.80 per 10,000 hospitalized patients. The estimated difference in hospital costs of patients with an aspergillosis infection is US$36,867 to US$59,356 higher than those of patients without the infection. Voriconazole is a synthetic, broad spectrum triazole antifungal agent, with FDA-approved indications for the treatment of invasive aspergillosis, esophageal candidiasis, candidemia in nonneutropenic patients, invasive candidiasis, and infections due to Scedosporium apiospermum and Fusarium species in patients refractory to or intolerant of other therapy. Eight cost-effectiveness analyses, one cost-minimization analysis, and one cost analysis were identified from a Medline search. The 10 pharmacoeconomic analyses were conducted in six different countries comparing voriconazole to conventional amphotericin B, liposomal amphotericin B, itraconazole, and caspofungin. All the cost-effectiveness and cost-minimization analyses identified voriconazole as the most cost-effective therapy. The cost analysis demonstrated voriconazole cost-savings. While the acquisition costs of voriconazole are higher than those of conventional amphotericin B, the toxicity profile and rate of treatment success associated with voriconazole result in lower total treatment costs per successfully treated patient.

Cost-effectiveness of posaconazole versus fluconazole or itraconazole in the prevention of invasive fungal infections among neutropenic patients in the United States

OBJECTIVES

Clinical trial data indicate that posaconazole is superior to fluconazole (FLU) or itraconazole (ITRA) in preventing invasive fungal infections (IFIs) among neutropenic patients. Our objective was to assess the cost-effectiveness of posaconazole versus FLU or ITRA for prevention of IFIs among neutropenic patients.

METHODS

We used modeling techniques to assess the cost-effectiveness of posaconazole versus FLU or ITRA in the prevention of IFIs among patients with acute myelogenous leukemia (AML) or myelodysplastic syndromes (MDS) and chemotherapy-induced neutropenia. The probabilities of experiencing an IFI, IFI-related death, and death from other causes over 100 days of follow-up were estimated from clinical trial data. Long-term mortality, drug costs, and IFI treatment costs were obtained from secondary sources.

RESULTS

Posaconazole is associated with fewer IFIs per patient (0.05 vs. 0.11) relative to FLU or ITRA over 100 days of follow-up, and lower discounted costs ($3900 vs. $4500) and increased life-years (2.50 vs. 2.43 discounted) over a lifetime horizon. Results from a probabilistic sensitivity analysis indicate that there is a 73% probability that posaconazole is cost saving versus FLU or ITRA and a 96% probability that the incremental cost-effectiveness ratio for posaconazole is at or below $50,000 per life-year saved.

CONCLUSIONS

We conclude that posaconazole is very likely to be a cost-effective alternative to FLU or ITRA in the prevention of IFIs among neutropenic patients with AML and MDS, and may result in cost savings.

Economic impact of caspofungin as compared with liposomal amphotericin B for empirical therapy in febrile neutropenia in Australia

BACKGROUND

In a major clinical trial, caspofungin was as efficacious as liposomal amphotericin B (LAmB) for empirical therapy in febrile neutropenia. The current study sought to evaluate the economic impact of caspofungin as compared with LAmB for febrile neutropenia in Australia.

METHODS

A decision analytic model was developed to capture the downstream consequences of the empirical antifungal therapy. The main outcomes were success, breakthrough infection, persistent baseline infection, persistent fever, premature discontinuation and death. Underlying transition probabilities and treatment patterns were derived directly from trial data. Resource use was estimated using an expert panel. Cost inputs were obtained from the latest Australian representative sources. The perspective adopted was that of the Australian hospital system. Uncertainty and sensitivity analyses were undertaken via Monte Carlo simulation.

RESULTS

Caspofungin was associated with a net cost saving of AU$7245 (12.6%) per patient over LAmB (AU$50 267 versus AU$57 512). A similar trend was observed with cost per success and death prevented (AU$24 169 and AU$7270, respectively). Caspofungin dominated LAmB as it resulted in higher efficacy and lower costs when compared with LAmB. Persistent fever was the main contributing clinical outcome to the therapeutic costs of both antifungals. The results were most sensitive to therapy duration. Monte Carlo simulation suggested a 99.8% chance for LAmB to cost more than caspofungin.

CONCLUSIONS

This is the first economic study to evaluate the place of caspofungin as empirical therapy in Australia. Caspofungin is more cost-beneficial than LAmB, which contradicts the current Australian guidelines of recommending LAmB as the first choice for empirical therapy.

A multi-centre comparison of nursing staff time required for the preparation and administration of liposomal amphotericin B and amphotericin B deoxycholate vs. voriconazole

AIMS AND OBJECTIVES

To compare the nursing time and cost required for preparation and administration of liposomal amphotericin B, amphotericin B deoxycholate and voriconazole.

DESIGN

Cost comparison study.

METHODS

Nurse activities associated with the preparation and administration of the three study drugs were divided into 11 tasks and timed by observers at five hospitals. Target tasks were defined as those likely to be affected by the differences between drugs and excluded those tasks likely to differ owing to site-specific factors. Mean times for administration of a single day of therapy for each study drug were compared. Costs of preparation and administration of a 14-day regimen were estimated.

RESULTS

Sixty-nine patients were observed receiving a total of 256 doses of study medications. Labour times were 20, 16, 14 and 3 minutes per day for liposomal amphotericin B, amphotericin B deoxycholate, intravenous voriconazole and oral voriconazole, respectively. Administration time was significantly lower for intravenous voriconazole compared with liposomal amphotericin B (p < 0.05), and for oral voriconazole compared with all intravenous regimens (p < 0.05). Preparation of medications took the longest time for intravenous formulations and was longer for liposomal amphotericin B than for the other drugs by 3-5 minutes. Average non-drug costs associated with preparation and administration of a 14-day regimen were greatest in the amphotericin B deoxycholate arm at US$ 335, followed by liposomal amphotericin B (US$ 310) and voriconazole (US$ 180).

CONCLUSION

Intravenous voriconazole required less time to prepare and administer on a daily basis than liposomal amphotericin B, and was similar to amphotericin B deoxycholate. Measurements of intravenous vs. oral voriconazole administration suggest the opportunity to save 10-17 minutes per day with the oral formulation.

RELEVANCE TO CLINICAL PRACTICE

Oral voriconazole may provide significant savings in terms of nursing time compared with intravenous antifungal drugs.

Voriconazole treatment of invasive aspergillosis: real-world versus health-economic model results

OBJECTIVE

The objective of this study was to assess, in a real-world setting, the predictive validity (in terms of clinical outcome and treatment cost) of the voriconazole arm of a health-economic model applied in the Belgian reimbursement submission for use of voriconazole in the treatment of invasive aspergillosis.

METHODS

A non-interventional study was designed to prospectively collect clinical response and direct costs data related to the treatment of invasive aspergillosis with voriconazole (oral, intravenous) in real-world practice. The outcomes of this study were compared with the inputs and outputs of the health-economic model. For the analysis, unit costs of 2002 from the public payer's perspective, as used in the model, were applied.

RESULTS

Data from 116 patients with invasive aspergillosis starting treatment with voriconazole were collected. At 12 weeks, there were similar rates of satisfactory clinical response for the observational study and the model, the latter based on the results of a clinical study (50% vs 53%, respectively). Overall mortality rates at 84 days were 42% in the observational study and 29% in the model. Average total healthcare cost associated with voriconazole treatment was lower in the observational study compared with the model for all patients. When the cost for all hospitalization days from the start until the end of the fungal infection was included in the analysis, the average total cost was euro19,674. When the cost for only those hospitalization days solely related to the fungal infection was included in the analysis, the average total cost was euro12,376. These costs are below the cost predicted by the model of euro21,298.

CONCLUSIONS

This analysis demonstrates that the results provided in the voriconazole arm of the health-economic model were valid estimates with regard to real-world outcomes but with a slightly better survival rate and higher costs than in real life.

[Diagnostic strategy for acute respiratory failure in patients with haematological malignancy]

INTRODUCTION

About 15% of patients with haematological malignancy develop acute respiratory failure (ARF), necessitating admission to intensive care where their mortality is of the order of 50%.

STATE OF THE ART

The prognosis of these patients is not determined by the pathological characteristics of the malignancy but by the cause of the acute respiratory failure. In effect, the need to resort to mechanical ventilation in the presence of dysfunction of other organs dominates the prognosis. Even if the use of non-invasive ventilation in these patients has reduced the need for intubation and reduced the mortality, its prolonged use in the most severely affected patients prevents the optimal diagnostic and therapeutic management.

PERSPECTIVES

Fibreoptic bronchoscopy with broncho-alveolar lavage (BAL) is considered the cornerstone of aetiological diagnosis but its diagnostic effectiveness is poor, at best 50%, and this has led to increasing interest in high resolution CT scanning and regularly reawakens a transitory enthusiasm for surgical lung biopsy. Furthermore, in hypoxaemic patients, fibreoptic bronchoscopy with BAL may be the origin of the resort to mechanical ventilation, and thus increased mortality. The place of recently developed non-invasive tools is under evaluation. In effect, though the individual performance of diagnostic molecular techniques on sputum, blood, urine or naso- pharyngeal secretions has been established, the combination of these tools as an alternative to BAL has not yet been reported.

CONCLUSION

This review deals with acute respiratory failure in patients with haematological malignancy. It includes a review of the recent literature and considers the current controversies, in particular the risk-benefit balance of fibreoptic bronchoscopy with BAL in severely hypoxaemic patients.

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

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

Antifungal agents

The four main classes of antifungal drugs are the polyenes, azoles, allylamines and echinocandins. Clinically useful "older" agents include topical azole formulations (for superficial yeast and dermatophyte infections), first-generation triazoles (fluconazole and itraconazole, for a range of superficial and invasive fungal infections), amphotericin B formulations (for a broad range of invasive fungal infections) and terbinafine (for dermatophyte infections). Clinically important "newer" agents include members of the echinocandin class (eg, caspofungin) and second-generation triazoles (eg, voriconazole and posaconazole). Voriconazole and posaconazole have broad-spectrum activity against yeasts and moulds, including Aspergillus species. Posaconazole is the only azole drug with activity against zygomycete fungi. Caspofungin and the other echinocandins are effective in treating Candida and Aspergillus infections. The azoles are relatively safe, but clinicians should be aware of drug-drug interactions and adverse effects, including visual disturbances (with voriconazole), elevations in liver transaminase levels, and skin rashes. Caspofungin has minimal adverse effects. Combination antifungal therapy may be appropriate in selected patients with invasive fungal infections, but is empiric and driven by individual physician practice.

Resource use and cost of treatment with voriconazole or conventional amphotericin B for invasive aspergillosis

BACKGROUND

Voriconazole, a broad-spectrum triazole, has demonstrated significantly improved survival compared with conventional amphotericin B (CAB) as initial therapy for invasive aspergillosis (IA).

OBJECTIVE

To compare health care resource use and cost at 12 weeks following first-line treatment with voriconazole compared with CAB for IA using resource use data collected during a clinical trial.

METHODS

Days of hospitalization, intensive care, antifungal drug use, and outpatient care were collected during a large randomized, controlled trial of patients with IA receiving initial treatment with voriconazole or CAB. Unit costs based on published data sources were applied to healthcare use to estimate 12-week costs following initiation of therapy. Resource use and costs were compared for each treatment arm overall and by survival. The sensitivity of total costs to changes in healthcare use and unit costs was examined.

RESULTS

Total hospital days and intensive care unit (ICU) days were similar for voriconazole and CAB (total: 27.8 vs. 27.7, P=0.97 and ICU: 5.6 vs. 8.1, P=0.11). Among survivors, voriconazole was associated with similar numbers of total hospital days (29.8 vs. 32.0 days, P=0.54) to CAB, but fewer ICU days (3.9 vs. 8.2, P=0.03). For non-survivors, those treated with voriconazole had a similar number of total hospital days (23.0 vs. 21.8, P=0.73) and ICU days (9.8 vs. 7.9, P=0.44). Patients treated with voriconazole had significantly more days alive and out of the hospital than with CAB at 12 weeks (40.3 vs. 28.4 days, P<0.001). Total costs were similar with voriconazole compared with CAB ($78,860 vs. $83,857, P=0.51). Differences in cost were not sensitive to changes in the input parameter values.

CONCLUSIONS

Using voriconazole first-line for treatment of IA resulted in significantly fewer deaths and similar treatment costs. Hospital-free survival was significantly greater for patients initially treated with voriconazole.

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.

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.

Pulmonary dysfunction in pediatric hematopoietic stem cell transplant patients: overview, diagnostic considerations, and infectious complications

Pulmonary complications are among the most common and serious sequelae seen in hematopoietic stem cell transplantation (HSCT) recipients. This two-part review addresses the incidence and impact of pulmonary complications in pediatric HSCT patients. In this first part we review the available data for the use of diagnostic modalities in this population, including flexible bronchoscopy with bronchoalveolar lavage (BAL) and open lung biopsy (OLB). We also review the many infectious pulmonary complications that may occur in pediatric HSCT recipients, utilizing the traditional chronologic divisions of neutropenic phase (0-30 days following HSCT), early phase (30-100 days), and late phase (>100 days).

Economic evaluation of targeted treatments of invasive aspergillosis in adult haematopoietic stem cell transplant recipients in the Netherlands: a modelling approach

OBJECTIVES

The aim of this study was to assess the cost-effectiveness of a targeted treatment model of antifungal treatment strategies for adult haematopoietic stem cell transplant (HSCT) recipients in the Netherlands from a hospital perspective, using a decision analytic modelling approach.

METHODS

The economic evaluation of desoxycholate amphotericin B, liposomal amphotericin B, voriconazole and caspofungin was undertaken. These drugs could be used alone, in various combinations or sequentially. In our model, first-line therapy consisted of either voriconazole or liposomal amphotericin B. If necessary, treatment was switched to a second-line treatment, including combination antifungal therapy. The theoretical population in this model consisted of adult HSCT recipients with proven or probable invasive aspergillosis (IA). Long-term survival was extrapolated from survival after 12 weeks of treatment and life expectancy.

RESULTS

First-line antifungal treatment strategies with voriconazole were both more effective and less costly over first-line strategies employing liposomal amphotericin B at a dosage of 4 mg/kg/day. The strategy of voriconazole followed by caspofungin (voriconazole/caspofungin) was dominant over the strategies of voriconazole followed by liposomal amphotericin B (voriconazole/liposomal amphotericin B) or desoxycholate amphotericin B (voriconazole/desoxycholate amphotericin B). However, the voriconazole followed by the combination of liposomal amphotericin B and caspofungin strategy (voriconazole/liposomal amphotericin B+caspofungin) was more effective though more expensive than the voriconazole/caspofungin strategy resulting in an incremental cost-effectiveness ratio (ICER) of about euro107,000 for a life-year saved. At a dosage of 1 mg/kg/day of liposomal amphotericin B, the voriconazole/caspofungin strategy was more effective but more costly than the voriconazole/desoxycholate amphotericin B strategy with an ICER of euro10,000 for each extra life-year saved. Between the voriconazole/liposomal amphotericin B+caspofungin and the voriconazole/caspofungin strategies, the ICER was euro40,000.

CONCLUSIONS

Probabilistic analyses on net monetary benefit showed that the voriconazole/caspofungin strategy had the highest probability of being the most cost-effective strategy.

Voriconazole : a review of its use in the management of invasive fungal infections

Voriconazole (VFEND), a synthetic second-generation, broad-spectrum triazole derivative of fluconazole, inhibits the cytochrome P450 (CYP)-dependent enzyme 14-alpha-sterol demethylase, thereby disrupting the cell membrane and halting fungal growth. In the US, intravenous and/or oral voriconazole is recommended in adults for the treatment of invasive aspergillosis, candidaemia in non-neutropenic patients, disseminated infections caused by Candida spp., oesophageal candidiasis, and in patients with scedosporiosis and fusariosis who are refractory to or intolerant of other antifungal therapy. In Europe, intravenous and/or oral voriconazole is recommended in adults and paediatric patients of at least 2 years of age for the treatment of invasive aspergillosis, candidaemia in non-neutropenic patients, fluconazole-resistant serious invasive Candida spp. infections, scedosporiosis and fusariosis. In large randomised trials, voriconazole was an effective and generally well tolerated primary treatment for candidiasis and invasive aspergillosis in adults and adolescents. More limited data also support the use of voriconazole for the treatment of invasive fungal infections in children, in those with rare fungal infections, such as Fusarium spp. or Scedosporium spp., and in those refractory to or intolerant of other standard antifungal therapies. The availability of both parenteral and oral formulations and the almost complete absorption of the drug after oral administration provide for ease of use and potential cost savings, and ensure that therapeutic plasma concentrations are maintained when switching from intravenous to oral therapy. On the other hand, the numerous drug interactions associated with voriconazole may limit its usefulness in some patients. Further clinical experience will help to more fully determine the position of voriconazole in relation to other licensed antifungal agents. In the meantime, voriconazole is a valuable emerging option for the treatment of invasive aspergillosis and rare fungal infections, including Fusarium spp. and Scedosporium spp. infections, and provides an alternative option for the treatment of candidiasis, particularly where the causative organism is inherently resistant to other licensed antifungal agents.

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.

Voriconazole: a broad spectrum triazole for the treatment of serious and invasive fungal infections

For many years, serious systemic fungal infections have been treated with amphotericin B or narrow-spectrum azole antifungals. These treatments have been effective in many patients, but are associated with tolerability or pharmacokinetic concerns, or suboptimal antifungal activity in some patient groups. Voriconazole is a second-generation triazole with an extended spectrum of activity offering the potential to treat life-threatening fungal infections. The drug is available for intravenous or oral administration and has been shown to be effective in invasive aspergillosis, fluconazole-susceptible and -resistant candidiasis, and infections caused by various other fungal pathogens, including some formerly refractory organisms. Voriconazole is generally well tolerated with transient visual disturbances, liver enzyme abnormalities and skin rashes being the most common adverse events reported, but these rarely lead to treatment discontinuation.

Economic evaluation of the prevention and management of systemic fungal infections in neutropenic patients

Systemic fungal infections in neutropenic patients remain a clinical problem that is associated with morbidity and mortality. Continuing efforts are being made to develop improved (i.e., more effective or safe) drugs, and several new treatments have recently become available. These have increased the therapeutic options available to clinicians to address the problem of systemic fungal infections. Therapeutic choices are difficult when taking into account aspects of efficacy, safety and costs that are associated with the available alternatives. This review summarises the present status of health economic knowledge of the standard therapies that have been available for many years, and also reports on the most recent health economic evidence available for the newly developed treatment alternatives.

Diagnostic strategy in cancer patients with acute respiratory failure

OBJECTIVE

Nearly 15% of cancer patients experience acute respiratory failure (ARF) requiring admission to the intensive care unit, where their mortality is about 50%. This review focuses on ARF in cancer patients. The most recent literature is reviewed, and emphasis is placed on current controversies, most notably the risk/benefit ratio of fiberoptic bronchoscopy and BAL in patients with severe hypoxemia.

BACKGROUND

Fiberoptic bronchoscopy with bronchoalveolar lavage (BAL) is the cornerstone of the causal diagnosis. However, the low diagnostic yield of about 50%, related to the widespread use of broad-spectrum antimicrobial therapy in cancer patients, has generated interest in high-resolution computed tomography (HRCT) and primary surgical lung biopsy. In patients with hypoxemia, bronchoscopy and BAL may trigger a need for invasive mechanical ventilation, thus considerably decreasing the chances of survival.

DISCUSSION

The place for recently developed, effective, noninvasive diagnostic tools (tests on sputum, blood, urine, and nasopharyngeal aspirates) needs to be determined. The prognosis is not markedly influenced by cancer characteristics; it is determined chiefly by the cause of ARF, need for mechanical ventilation, and presence of other organ failures. Although noninvasive ventilation reduces the need for endotracheal intubation and diminishes mortality rate, its prolonged use in patients with severe disease may preclude optimal diagnostic and therapeutic management. The appropriateness of switching to endotracheal mechanical ventilation in patients who fail noninvasive ventilation warrants evaluation.

CONCLUSION

This review discusses risks and benefits from invasive and non invasive diagnostic and therapeutic strategies in critically ill cancer patients with acute respiratory failure. Avenues for research are also suggested in order to improve survival in these very high risk patients.