Isavuconazole in Hematological Patients: Results of a Real-Life Multicentre Observational Seifem Study

Effectiveness, Safety, and Patterns of Real-World Isavuconazole Use in Europe (2015-2019)

INTRODUCTION

Real-world data from multinational observational studies are required to better understand the role and performance of isavuconazole in real-world practice in Europe.

METHODS

A retrospective medical record review was conducted at 16 sites in Europe (France, Germany, Italy, Spain, and the United Kingdom). Eligible records were from patients aged ≥ 18 years at the time of isavuconazole initiation and received at least one dose of isavuconazole for suspected or confirmed invasive aspergillosis (IA) or invasive mucormycosis (IM) during the eligibility period (October 15, 2015 to June 30, 2019). Data were descriptively analysed. Success rates, overall survival, and times to these events were descriptively analysed.

RESULTS

Data were abstracted from 218 patients (201, IA; 17, IM) who received isavuconazole as monotherapy (initiated as infusion, 52%; oral, 46%). Isavuconazole was initiated as primary therapy in 92 patients (42.2%) and salvage therapy in 121 patients (55.5%) (unknown for five patients). Mean (standard deviation) age was 56.8 (15.6) years, 66% were men and 62% had at least three comorbidities, most frequently haematologic malignancy (62%). Estimated clinical response rate at week 24 was 54.5% (95% confidence interval [CI], 38.2-66.5%) for primary treatment and 73.5% (95% CI, 62.7-81.1%) for salvage therapy. Overall, 45 patients (21%) experienced at least one adverse event (AE). Serious AEs were experienced by 37 patients (17%), with seven related to isavuconazole; five patients (2.3%) discontinued isavuconazole monotherapy due to the serious AE. A total of 137 patients (63%) died, with 17 deaths (12.4%) related to their invasive fungal infection, 11 of whom initiated isavuconazole as salvage therapy.

CONCLUSIONS

This study adds to the growing body of evidence that whether used as first-line therapy or after the failure of other antifungal therapies, isavuconazole appears to have a promising clinical response and a good safety profile as an antifungal agent in patients with varied underlying conditions.

Real-World Experience with Isavuconazole in Allogeneic Stem Cell Transplantation in Spain

Invasive fungal infections (IFI) pose a significant complication after hematopoietic stem cell transplantation (HSCT). Isavuconazole (ISV) is a new generation azole with a favourable adverse effect and interaction profile approved for the treatment of invasive aspergillosis and mucormycosis. We analyzed the indications, effectiveness, adverse event profile and drug interaction management of ISV in the real-world setting in adults who received allogeneic-HSCT (allo-HSCT) within the Spanish Group of HSCT and Cell Therapy (GETH-TC). We conducted a multicenter retrospective study of all consecutive adult allo-HSCT recipients (≥18 years) who received ISV either for IFI treatment or prophylaxis, from December 2017 to August 2021, in 20 centers within the Spanish Group of Hematopoietic Stem Cell Transplantation and Cell Therapy (GETH-TC). A total of 166 adult allografted patients who received ISV from 2017 to 2021 were included. Median age was 48 years with 43% females. In 81 (49%) patients, ISV was used for treatment of IFI, and in 85 (51%) for prophylaxis. Median duration of ISV administration for IFI treatment was 57 days (range 31-126) and 86 days (range 33-196) for prophylaxis. Most frequent indication for treatment was invasive aspergillosis (78%), followed by mucormycosis (6%). Therapeutic success (45%) was the most frequent reason for ISV withdrawal. In the prophylaxis group, the resolution of IFI risk factors was the most frequent reason for withdrawal (62%). Six (7%) breakthrough IFI were reported. The majority of patients (80%) presented pharmacologic interactions. Twenty-one patients (13%) reported adverse events related to ISV, mainly liver biochemistry abnormalities, which led to ISV withdrawal in 7 patients (4%). ISV was effective and well tolerated for IFI treatment and prophylaxis, with a manageable interaction profile.

A global perspective of the changing epidemiology of invasive fungal disease and real-world experience with the use of isavuconazole

Global epidemiological data show that the incidence of invasive fungal disease (IFD) has increased in recent decades, with the rising frequency of infections caused by Aspergillus and Mucorales order species. The number and variety of patients at risk of IFD has also expanded, owing in part to advances in the treatment of hematologic malignancies and other serious diseases, including hematopoietic stem cell transplantation (HCT) and other therapies causing immune suppression. Isavuconazonium sulfate (active moiety: isavuconazole) is an advanced-generation triazole antifungal approved for the treatment of invasive aspergillosis and mucormycosis that has demonstrated activity against a variety of yeasts, moulds, and dimorphic fungi. While real-world clinical experience with isavuconazole is sparse in some geographic regions, it has been shown to be effective and well tolerated in diverse patient populations, including those with multiple comorbidities who may have failed to respond to prior triazole antifungal therapy. Isavuconazole may be suitable for patients with IFD receiving concurrent QTc-prolonging therapy, as well as those on venetoclax or ruxolitinib. Data from clinical trials are not available to support the use of isavuconazole prophylactically for the prevention of IFD or for the treatment of endemic IFD, such as those caused by Histoplasma spp., but real-world evidence from case studies suggests that it has clinical utility in these settings. Isavuconazole is an option for patients at risk of IFD, particularly when the use of alternative antifungal therapies is not possible because of toxicities, pharmacokinetics, or drug interactions.

Coadministration of isavuconazole and sirolimus in allogeneic hematopoietic stem cell transplant recipients

Background

Invasive fungal infections (IFIs) represent a major cause of morbidity among allogeneic hematopoietic stem cell transplantation (allo-HSCT). Isavuconazole (ISA) is a broad-spectrum triazole with favorable safety profile.

Objectives and design

Herein, we evaluate the real life coadministration of ISA and sirolimus in allo-HSCT recipients in a single-center retrospective analysis, describing clinical efficacy, safety, and therapeutic drug monitoring (TDM) of both drugs.

Methods

All consecutive allo-HSCT recipients who received the coadministration of ISA and sirolimus for at least 2 weeks between July 2017 and December 2022 were included in this retrospective analysis. TDM was longitudinally performed during treatment. IFIs were classified according to the revised European Organization for Research and Treatment of Cancer/Mycoses Study Group consensus criteria.

Results

A total of 51 recipients were included in the analysis. A total of 17 patients received ISA as continuous antifungal treatment for IFI diagnosed before transplant: one patient experienced a probable invasive pulmonary aspergillosis, and one patient switched from ISA to liposomal amphotericin B for a possible IFI. A total of 34 patients started ISA as antifungal therapy for IFI diagnosed after transplant. Sixteen of 34 were treated for a proven/probable breakthrough IFI during mold-active prophylaxis: 6/16 patients died for IFI after a median of 51 days of ISA. Eighteen of 34 started ISA as empirical therapy for a possible IFI: 15/18 patients were alive with resolution of infection after 6 weeks, 1 died for disease progression, and 2 had empirically changed antifungal therapy due to pneumonia progression. Clinical and radiological response rate was 68% after 90 days from IFI diagnosis. No toxicities related to drug-drug interaction have been registered in patients reaching concomitant therapeutic levels of ISA and sirolimus.

Conclusion

The coadministration of ISA and sirolimus was safe and feasible in this cohort, confirming favorable clinical efficacy in patients with multiple-drug coadministration.

Real-World, Multicenter Case Series of Patients Treated with Isavuconazole for Invasive Fungal Disease in China

BACKGROUND

The incidence of invasive fungal disease (IFD) has increased significantly, and IFD is a major cause of mortality among those with hematological malignancies. As a novel second-generation triazole antifungal drug offering both efficacy and safety, isavuconazole (ISA) is recommended by various guidelines internationally for the first-line treatment of invasive aspergillosis (IA) and invasive mucormycosis (IM) infecting adults. Given that it was only approved in China at the end of 2021, there is currently a lack of statistical data regarding its usage in the Chinese population. The primary objective of this report is to describe early experiences with ISA for the treatment of IFD.

METHODS

This was a real-world, multicenter, observational case series study conducted in China. It included patients from three centers who received ISA treatment from January 2022 to April 2023. A retrospective assessment on patient characteristics, variables related to ISA administration, the treatment response of IFD to ISA, and potential adverse events attributed to ISA was conducted.

RESULTS

A total of 40 patients met the inclusion criteria. Among them, 12 (30%) were diagnosed with aspergillosis, 2 (5%) were diagnosed with candidiasis, 12 (30%) were diagnosed with mucormycosis, and 14 cases did not present mycological evidence. The predominant site of infection was the lungs (36), followed by the blood stream (8), sinuses (4), and respiratory tract (2). The overall response rate was 75% (30 patients), with male patients having a higher clinical response than female patients (24/24 versus 6/16, p = 0.000) and autologous stem cell transplant patients having a higher clinical response than allogeneic stem cell transplant patients (6/6 versus 4/10, p = 0.027). During the observation period, four patients experienced adverse effects associated with ISA, but none of them discontinued the treatment.

CONCLUSIONS

Our findings suggest that ISA, a novel first-line treatment for IA and IM, is associated with a high clinical response rate, low incidence, and a low grade of adverse effects. Given the short time that ISA has been available in China, further research is needed to identify its efficacy and safety in the real world.

Efficacy and safety of Isavuconazole for the treatment of invasive Aspergillus infection - an update of the literature

INTRODUCTION

Invasive aspergillosis is associated with high morbidity and mortality in immunocompromised patients. It is now increasingly reported in critically ill patients, including those with respiratory viral infections, such as influenza and COVID-19. Antifungal management is challenging due to diagnostic delay, adverse drug reactions, drug-drug interactions, narrow therapeutic window, and the emergence of resistance. Isavuconazole is the most recent FDA approved azole for the treatment of invasive aspergillosis, with data continuing to accumulate.

AREAS COVERED

The authors review the safety and efficacy of isavuconazole in the management of invasive aspergillosis based on the currently available evidence. The authors also report on the structure, mechanism of action, pharmacokinetic properties, in vitro and in vivo studies as well as clinical safety and efficacy reports of isavuconazole since its FDA approval.

EXPERT OPINION

Isavuconazole is non-inferior to voriconazole and is a safe, effective, and better tolerated option for the treatment of invasive aspergillosis. It offers several advantages over other antifungal agents, including having a better adverse event profile with respect to hepatotoxicity, neuro-visual toxicity, QTc prolongation, as well as a stable pharmacokinetic profile obviating the need for therapeutic drug monitoring. Further studies are needed to evaluate its performance in prophylaxis against invasive aspergillosis as well as in the treatment of aspergillosis in critically ill patients without underlying cancer or transplant.

Therapeutic Drug Monitoring of Isavuconazole: Serum Concentration Variability and Success Rates for Reaching Target in Comparison with Voriconazole

Isavuconazole (ISZ) is used in the treatment of aspergillosis and mucormycosis. The purpose of this study was to evaluate the therapeutic drug monitoring (TDM) of ISZ samples from a clinical setting performed at Statens Serum Institut. Materials/methods: Isavuconazole serum concentrations were determined by fluorescent detection on a UHPLC. Serum-ISZ (s-ISZ) results were included and compared to those of serum-voriconazole (s-VRZ) in a 33 month period from March 2017. Clinical data were obtained for patients receiving ISZ. The therapeutic range was initially 2-10 mg/L, but was adjusted to 2-5 mg/L during the study period except for selected patients with Mucorales infections who received off-label doses of ISZ. Results: A total of 273 s-ISZ and 1242 s-VRZ measurements from 35 and 283 patients, respectively, were included. Seventeen patients had received both ISZ and VRZ with TDM within the study period. The median s-ISZ was 4.3 mg/L (0.5-15.4 mg/L) with 83% of measurements within the therapeutic index. The median s-VRZ was 2.6 mg/L (0.2-21.9 mg/L) with 67% of measurements within the therapeutic index. The median intra-/interindividual coefficient of variation (CV) was 43.4%/54.8% for ISZ compared to 53.2%/83.3% for VRZ. For patients receiving ISZ, the adverse events were mostly gastroenteric and few drug-drug interactions were observed. Furthermore, immediate change from ISZ to VRZ treatment seemed to lead to prolonged metabolism of ISZ with detection up to 35 days after discontinuation. Conclusions: The majority of patients achieved s-ISZ levels well within the therapeutic range with less intra/interindividual CV than patients receiving VRZ.

Isavuconazole-Animal Data and Clinical Data

The treatment of invasive fungal infections has deeply evolved in the last years with the inclusion of new antifungals, mainly new azoles (i.e., posaconazole, isavuconazole), to the therapeutic armamentarium. This review focuses on the role of isavuconazole for treating the most important invasive fungal infections both in animals and humans (hematological and non-hematological patients).