Voriconazole in the management of invasive aspergillosis in two patients with acute myeloid leukemia undergoing stem cell transplantation

Successful treatment of cerebral aspergillosis: case report of a patient with T-cell large granular lymphocytic leukemia (T-LGL)

Background

Invasive aspergillosis involving patients with neutropenia or severe immunosuppression, such as patients with hematologic malignancies is associated with high mortality. Patients with T-cell large granular lymphocytic leukemia (T-LGL) on the other hand are considered to be less vulnerable for severe opportunistic fungal infection as their course of disease is chronic and marked by less violent cytopenia then in e.g. Aplastic Anemia. Only neutropenia is regarded as independent risk factor for severe opportunistic infection in T-LGL patients.

Case presentation

We report a case of a 53 year old patient with T-LGL, Immune-Thrombocytopenia (ITP) and combined antibody deficiency, who presented with fever and reduced general condition. The patient revealed a complicated infection involving the lungs and later the brain, with the presentation of vomiting and seizures. Broad microbiological testing of blood-, lung- and cerebrospinal fluid samples was inconclusive. In the absence of mycological proof, Aspergillus infection was confirmed by pathological examination of a brain specimen and finally successfully treated with liposomal amphotericin B and voriconazole, adopting a long-term treatment scheme.

Conclusions

Beyond typical problems in the clinical practice involving fungal infections and hematologic malignancies, this case of invasive aspergillosis in a patient with T-LGL illustrates caveats in diagnosis, therapy and follow-up. Our data support careful ambulatory monitoring for patients with T-LGL, even in the absence of neutropenia. Especially those patients with combined hematologic malignancies and immune defects are at risk. Long-term treatment adhesion for 12 months with sufficient drug levels was necessary for sustained clearance from infection.

Successful management of pulmonary hemorrhage and aspergillosis in a patient with acute myeloid leukemia (AML-M3)

A 35-year-old man presented with a one month history of gingival bleeding. He was diagnosed with Acute Myeloid Leukemia (AML-M3). During treatment he developed alveolar hemorrhage for which he was treated with a steroid. After the steroid treatment he developed a nodule, a cavitary lesion and atelectasia in the left lung. He was treated with voriconazole. After therapy with voriconazole his lesion significantly decreased. This case illustrates the efficacy and safety of antifungal therapy with voriconazole for aspergillosis complicated by AML.

Voriconazole in the management of nosocomial invasive fungal infections

Voriconazole is a new triazole developed for the treatment of life-threatening fungal infections. The drug is available for both oral and intravenous administration; the oral formulation has excellent bioavailability. The side-effect profile of voriconazole presents an acceptable safety and tolerability spectrum: transient visual disturbances, liver enzyme abnormalities, and skin rashes are the most frequently reported side effects but rarely lead to discontinuation. The potential for drug–drug interactions is high, because of its extensive hepatic metabolism. Careful attention to dosage is required, and serum levels and the effects of interacting drugs should be monitored. Review of 25 470 isolates of yeasts and 3216 isolates of filamentous fungi showed voriconazole to have broad-spectrum activity against pathogenic yeasts including intrinsically fluconazole-resistant isolates such as Candida krusei, dimorphic fungi, and opportunistic moulds like Aspergillus spp, amphotericin-B-resistant Aspergillus terreus, Fusarium spp, and Scedosporium apiospermum. It displays excellent clinical efficacy in patients with fluconazole-resistant and -susceptible Candida infections, invasive bone and central nervous system aspergillosis, and various refractory fungal infections. Voriconazole has been approved by the US Food and Drug Administration and by the European Medicines Agency for the treatment of invasive aspergillosis, serious infections caused by Fusarium and S. apiospermum, fluconazole-resistant invasive Candida infections, and candidemia in nonneutropenic patients.

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.

Successful allogeneic transplantation of patients with suspected prior invasive mold infection

Prior invasive fungal infection (IFI) has historically limited the use of allogeneic stem cell transplantation for patients with hematologic malignancies. Transplantation of such patients frequently resulted in recurrent infection and high mortality rates. Several new antifungal agents have been introduced over the past 5 years with broader spectra of activity against molds such as Aspergillus and a favorable toxicity profile. In this study, we present a series of 16 consecutive patients with hematologic malignancy and prior invasive fungal infection who underwent allogeneic transplantation. Of these patients, the majority of whom were treated with voriconazole and/or caspofungin, only four experienced recurrent fungal infection and recurrent fungal infection was the primary cause of death in only one patient. The estimated 45% 2-year survival in this series is similar to that for other patients with high risk hematologic malignancy undergoing stem cell transplantation. We conclude that suspected prior invasive fungal infection should not preclude the use of allogeneic stem cell transplantation.

Nebulized liposomal amphotericin B and combined systemic antifungal therapy for the treatment of severe pulmonary aspergillosis after allogeneic hematopoietic stem cell transplant for a fatal mitochondrial disorder

Nebulized liposomal amphotericin B (20-15 mg twice daily by nebulizer) was combined with high dose intravenous liposomal amphotericin B (10 mg/kg/day) and high dose caspofungin (100 mg/m(2)) for the treatment of severe, recurrent pulmonary aspergillosis following allogeneic hematopoietic stem cell transplantation from alternative donor in a patient with mitochondrial disease (Pearson's syndrome). This combined treatment was administered for 8 days. Nebulized liposomal amphotericin B was well tolerated. Since severe transplant complications developed, nebulized administration was withdrawn and intravenous doses of liposomal amphotericin B and caspofungin were tapered to usual schedules. Pulmonary aspergillosis responded well to 45 days of combined intravenous antifungal therapies which were maintained for 2 years with secondary prophylaxis, because of persistent immunosuppressive treatment.

Clinical Issues Regarding Relapsing Aspergillosis and the Efficacy of Secondary Antifungal Prophylaxis in Patients with Hematological Malignancies

Advancements in early diagnosis and the introduction of effective agents have improved the rates of response of aspergillosis to primary antifungal therapy. These changes allow the subsequent continuation of cytotoxic chemotherapy and/or performance of hematopoietic stem cell transplantation in an increasing number of patients with hematological malignancies. These developments have increased interest in secondary prophylaxis of aspergillosis, because the resumption of myelotoxic chemotherapy in these patients is associated with high rates of relapse of this opportunistic mycosis in the absence of prophylaxis. However, the risk factors for relapsing invasive aspergillosis and the strategies for reducing risk are not well defined. Furthermore, differentiating aspergillosis relapse from reinfection with a new Aspergillus isolate is problematic when using the available laboratory tools. We summarize the existing knowledge regarding the pathogenesis of, risk factors for, and natural history of relapsing invasive aspergillosis and review the limited data regarding the role of secondary antifungal prophylaxis.

Aspergillus pulmonary infections in transplant recipients

Aspergillus infections are increasing in frequency in those undergoing solid organ and hematopoietic stem cell transplantation. The ongoing impact of Aspergillus infection on morbidity and mortality after transplantation makes this subject an area of intense clinical and research interest. This article discusses the evolving epidemiologic features of the infection and its management and diagnosis.

Aspergillus infections in transplant recipients

Aspergillus infections are occurring with an increasing frequency in transplant recipients. Notable changes in the epidemiologic characteristics of this infection have occurred; these include a change in risk factors and later onset of infection. Management of invasive aspergillosis continues to be challenging, and the mortality rate, despite the use of newer antifungal agents, remains unacceptably high. Performing molecular studies to discern new targets for antifungal activity, identifying signaling pathways that may be amenable to immunologic interventions, assessing combination regimens of antifungal agents or combining antifungal agents with modulation of the host defense mechanisms, and devising diagnostic assays that can rapidly and reliably diagnose infections represent areas for future investigations that may lead to further improvement in outcomes.

Histological examination of an eye with endogenous Aspergillus endophthalmitis treated with oral voriconazole: a case report

PURPOSE

To report the histological findings of an eye with severe Aspergillus endophthalmitis after oral treatment with voriconazole. METHODS. Case report.

RESULTS

Histopathological examination revealed no fungal elements in choroidal or retinal vessels. The hyphae were mainly restricted to the vitreal side of the preretinal inflammatory infiltrate. Since the treatment with voriconazole had not been completed at the time of enucleation, the clinical course with potential further limitation or regression of the lesion remains unsettled.

CONCLUSIONS

Endogenous Aspergillus endophthalmitis is a devastating condition often associated with immunodeficiency. The pathogenesis of this entity implies the primary invasion of choroidal and retinal vessels. The lack of antifungal drugs with high blood-ocular permeability results in an extremely poor visual prognosis. Our histological examination indicates promising activity and ocular penetration of the new antifungal agent voriconazole.

Secondary antifungal prophylaxis with voriconazole to adhere to scheduled treatment in leukemic patients and stem cell transplant recipients

Although the efficacy and safety of voriconazole to treat invasive fungal infections have been demonstrated in prospective trials, its use for secondary prophylaxis to prevent reactivation of these infections remains unknown. Delaying the scheduled treatment of leukemia until complete resolution of fungal infection may have major implications for prognosis. We report 11 leukemic patients with previous aspergillus (n=10) and candida (n=1) infection who received voriconazole 400 mg/day intravenously or orally for between 44 and 245 days. Nine patients were scheduled for allogeneic stem cell transplant, and two for consolidation therapy for acute leukemia. None of the patients had a relapse of fungal infection, and scheduled treatment was delayed only once. Voriconazole was well tolerated, except in one patient who had abnormal liver tests secondary to hepatic graft-versus-host disease, and one who had visual disturbances. This small but homogeneous series indicates that voriconazole may be useful to prevent fungal relapse during at-risk periods in leukemic patients. Prospective trials are warranted to confirm these encouraging results.

Voriconazole

BACKGROUND

Reports of resistance and intolerance to currently available antifungal agents are increasing. Voriconazole is a broad-spectrum azole antifungal agent structurally derived from fluconazole. It is indicated for the treatment of invasive aspergillosis and serious fungal infections caused by Scedosporium apiospermum and Fusarium species in patients who are unable to tolerate or are refractory to other antifungal therapy.

OBJECTIVE

This article reviews the pharmacologic and pharmacokinetic properties and clinical usefulness of voriconazole.

METHODS

Relevant information was identified through a search of MEDLINE (1966-December 2002), Iowa Drug Information Service (1966-December 2002), International Pharmaceutical Abstracts (1970-December 2002), and meeting abstracts of the Infectious Diseases Society of America (1996-2002) and the Interscience Conference on Antimicrobial Agents and Chemotherapy (1996-2002) using the terms voriconazole and UK-109,495.

RESULTS

In head-to-head comparative trials, voriconazole appeared to be as efficacious as amphotericin B for the treatment of invasive aspergillosis and the empiric treatment of fungal infections in patients with febrile neutropenia. In clinical studies, it was as efficacious as fluconazole for the treatment of oropharyngeal and esophageal candidiasis. The results of in vitro susceptibility studies and case reports suggested that voriconazole may be useful against fluconazole- and/or itraconazole-resistant strains of Candida. Although voriconazole may be associated with a lower incidence of serious systemic adverse effects compared with amphotericin B (13.4% vs 24.3% in 1 pivotal clinical study; P = NS), major adverse effects associated with voriconazole include visual abnormalities ( approximately 30%), skin reactions ( approximately 20%), and elevations in hepatic enzymes (< or =20%). Voriconazole is available as oral and intravenous formulations. Pharmacokinetically, it has widespread distribution, including penetration into cerebral tissue. However, as 80% of voriconazole is hepatically eliminated, primarily via the cytochrome P450 (CYP) isozymes CYP2C19, CYP3A4, and CYP2C9, voriconazole has a high potential for drug interactions, and dose reduction is recommended in patients with mild to moderate hepatic dysfunction (Child-Pugh class A or B). Oral voriconazole may be preferred in patients with a creatinine clearance <50 mL/min due to the potential accumulation of the solubilizing excipient in the parenteral formulation of voriconazole.

CONCLUSIONS

Voriconazole appears to be a useful alternative to conventional antifungal agents in cases of resistance or intolerance to initial therapy. However, dose adjustment is recommended in patients with hepatic dysfunction, as well as in those receiving medications that may interact with voriconazole via hepatic metabolism.