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Background Cerebral aspergillosis (CA) is associated with high mortality. According to the European Conference on Infections in Leukemia and the European Society of Clinical Microbiology and Infectious Diseases guidelines, the recommended first-line treatment for all forms of aspergillosis is voriconazole or isavuconazole. However, little is known about the efficacy and safety of isavuconazole in CA. Methods We conducted a European multicenter retrospective study of patients treated with isavuconazole for proven or probable CA between 2014 and 2022 and compared the outcomes with those of weighted control groups from the previously published French national cohort of CA, the Cerebral Aspergillosis Lesional Study (CEREALS). Results Forty patients from 10 countries were included. The main underlying conditions were hematological malignancies (53%) and solid-organ transplantation (20%). Isavuconazole was administered as a first-line treatment to 10 patients, primarily in combination therapy, resulting in control of CA in 70% of these cases. Thirty patients received isavuconazole after a median of 65 days on another therapy, mostly because of side effects (50%) or therapeutic failure (23%) of the previous treatment. Predominantly given as monotherapy, it achieved control of CA in 73% of the patients. Seventeen patients (43%) underwent neurosurgery. When measured, isavuconazole levels were low in cerebrospinal fluid but adequate in serum and brain tissue. Isavuconazole toxicity led to treatment interruption in 7.5% of the patients. Twelve-week mortality was 18%. Comparison with the CEREALS cohort showed comparable survival in patients receiving isavuconazole or voriconazole as a first-line treatment. Conclusions Isavuconazole appears to be a well-tolerated treatment. Mortality of CA treated with isavuconazole is similar to that reported with voriconazole. [ABSTRACT FROM AUTHOR]

Background New antifungal agents are required to mitigate against azole-resistant Aspergillus and drug-resistant non- Aspergillus moulds. The novel orotomide, olorofim (F2G, Manchester, UK), has potent fungicidal activity against Aspergillus including azole-resistant Aspergillus fumigatus, Lomentospora prolificans and Scedosporium spp. Development of olorofim-specific clinical breakpoints/epidemiological cut-off values requires reliable MIC data. Objectives Determine the in vitro activity of olorofim compared with standard antifungals against mould pathogens at an Australian hospital. Materials and methods Olorofim MICs were determined for 507 clinical mould isolates using the CLSI M38-A3 standard. MICs of amphotericin B, anidulafungin, posaconazole, voriconazole and isavuconazole were obtained using Sensititre™ YeastOne YO10 and AUSNMRCI panels (Thermo-Fisher Scientific). Results A. fumigatus sensu stricto was the commonest species (33.3%) followed by L. prolificans (18.3%), Scedosporium (11.4%) and Fusarium (6%) species. Olorofim modal MICs were ≤0.25 mg/L (MIC90 0.25 mg/L) for all Aspergillus except Aspergillus Section Usti (1 mg/L); MICs for nine azole-resistant/non-wild-type A. fumigatus ranged from 0.008 to 0.125 mg/L. The MIC90 of olorofim for L. prolificans was 0.5 mg/L, 0.25–0.5 mg/L for Scedosporium spp. and 8 mg/L for the F. solani complex but with modal MICs of 0.25 and 0.008 mg/L for F. oxysporum and F. proliferatum complexes, respectively. For Verruconis gallopava (n  = 10), the olorofim MIC90 was 0.06 mg/L (voriconazole MIC90 2 mg/L, isavuconazole MICs of 4–>8 mg/L). Olorofim had little activity against other dematiaceous moulds including Exophiala species. Conclusions Olorofim was highly active against Aspergillus spp. including azole-resistant A. fumigatus , L. prolificans , Scedosporium spp. and some Fusarium species with the new finding of potent activity against V. gallopava. [ABSTRACT FROM AUTHOR]

Objective To recommend precision dosing and improve therapeutic efficacy against invasive fungal disease, a physiologically based pharmacokinetic model (PBPK) of oral isavuconazole (ISA) was established and used to explore its disposition across populations in different physiological and pathological states. Methods Twenty-five pharmacokinetic (PK) studies of oral ISA were identified through a systematic search of PubMed. Concentration–time data were extracted using WebPlotDigitizer. Physiochemical parameters were obtained from published literature and DrugBank. Model development and simulation used the Simcyp population-based simulator, and visual predictive check and predictive error were used for the model evaluation. Probability of target attainment and the cumulative fraction of response analyses were performed for dose optimization. Results The developed PBPK model was successfully validated in different populations. Most predicted concentration–time points aligned with the observed data, with acceptable predictive errors for the critical parameters. We predicted the PK profiles and parameters of ISA in a population with severe hepatic impairment (HI), a population with obesity and paediatric patients aged 1 to less than 6 years old. The probability of target attainment and cumulative fraction of response analyses indicated that the population with severe HI should have half the maintenance dose. The population with obesity and population with severe HI should have a loading dose of 300 mg every 8 h for 2 days. For paediatric patients aged 1 to less than 6 years old, a weight-based dosing regimen (5.38 mg/kg) of ISA was suggested. Conclusion The predicted value aligns with observations, suggesting ISA's potential predictability in PK profiles for other populations. The recommended dosing regimens increase our understanding of the use of ISA in special populations. [ABSTRACT FROM AUTHOR]

Systemic antifungal therapy is critical for reducing the mortality from many invasive and chronic fungal infections. Triazole antifungals are the most frequently prescribed antifungals but require attention to dosing and drug interactions. Nearly 600 severe drug–drug interactions and over 1100 moderate interactions requiring dose modifications are described or anticipated with systemic antifungal agents (see https://www.aspergillus.org.uk/antifungal-drug-interactions/). In this article, we address the common and less common, but serious, drug interactions observed in clinical practice with triazole antifungals, including a group of drugs that cannot be prescribed with all or most triazole antifungals (ivabradine, ranolazine, eplerenone, fentanyl, apomorphine, quetiapine, bedaquiline, rifampicin, rifabutin, sirolimus, phenytoin and carbamazepine). We highlight interactions with drugs used in children and new agents introduced for the treatment of haematological malignancies or graft versus host disease (midostaurin, ibrutinib, ruxolitinib and venetoclax). We also summarize the multiple interactions between oral and inhaled corticosteroids and triazole antifungals, and the strategies needed to optimize the therapeutic benefits of triazole antifungal therapy while minimizing potential harm to patients. [ABSTRACT FROM AUTHOR]

Invasive fungal disease (IFD) remains a significant cause of morbidity and mortality in children undergoing transplantation. There is a growing armamentarium of novel antifungal agents recently approved for use or in late stages of clinical development. The overarching goal of this review is to discuss the mechanisms of action, spectrum of activity, stage of development, and pediatric-specific data for the following agents: encochleated amphotericin B deoxycholate, fosmanogepix, ibrexafungerp, isavuconazole, olorofim, opelconazole, oteseconazole, and rezafungin. Additionally, key drug attributes of these novel agents and their potential future therapeutic roles in pediatric transplant recipients are discussed. [ABSTRACT FROM AUTHOR]

Background Antifungal prophylaxis can prevent invasive fungal diseases (IFDs) in high-risk, immunocompromised patients. This study assessed the real-world use of mold-active triazoles (MATs) for the prevention of IFDs. Methods This subgroup analysis of a multicenter, observational, prospective registry in the United States from March 2017 to April 2020 included patients who received MATs for prophylaxis (isavuconazole, posaconazole, and voriconazole) at study index/enrollment. The primary objective was to describe patient characteristics and patterns of MAT use. Exploratory assessments included the frequency of breakthrough IFDs and MAT-related adverse drug reactions (ADRs). Results A total of 1177 patients (256 isavuconazole, 397 posaconazole, 272 voriconazole, and 252 multiple/sequenced MATs at/after index/enrollment) were included in the prophylaxis subgroup analysis. Patient characteristics were similar across MAT groups, but risk factors varied. Hematological malignancy predominated (76.5%) across all groups. Breakthrough IFDs occurred in 7.1% (73/1030) of patients with an investigator's assessment (5.0% [11/221] isavuconazole; 5.3% [20/374] posaconazole; 4.0% [9/226] voriconazole; and 15.8% [33/209] multiple/sequenced MATs). Aspergillus (29.5% [18/61]) and Candida (36.1% [22/61]) species were the most common breakthrough pathogens recovered. ADRs were reported in 14.1% of patients, and discontinuation of MATs due to ADRs was reported in 11.1% of patients (2.0% [5/245] isavuconazole; 8.2% [30/368] posaconazole; and 10.1% [27/267] voriconazole). Conclusions Breakthrough IFDs were uncommon in patients who received MATs for prophylaxis. Candida and Aspergillus species were the most commonly reported breakthrough pathogens. The discontinuation of MATs due to ADRs was infrequent. These findings support prophylactic strategies with isavuconazole, posaconazole, and voriconazole in high-risk patients. [ABSTRACT FROM AUTHOR]

We aimed to assess patient exposure to isavuconazole (ISZ) from samples received in our laboratory for therapeutic antifungal monitoring. We used liquid chromatography coupled with ultraviolet (UV) absorbance detection adapted from a multiplex-validated method with photodiode array (PDA) detection to monitor the analytes. The latter device allows the characterization of the azoles UV spectra. The method was validated according to international guidelines for efficient ISZ monitoring. The assay exhibited linearity between 0.25 and 16 mg/l for ISZ. Accuracy and intra- and inter-day precision were within acceptable ranges, and the method was successfully applied to quantify azoles and major metabolites from clinical samples collected from treated patients. We focus on ISZ blood concentrations and compared them to those of voriconazole, posaconazole, and itraconazole for a period of 5 years (2017–2021). Median ISZ concentration was 2.92 mg/l (interquartile range 1.82–5.33 mg/l) with 89% of measurements classified as adequate exposure (> 1 mg/l). Additionally, 71% of samples reach concentration values > 2 mg/l. Different ISZ exposure between adults to children were found. In conclusion, ISZ achieves excellent blood concentrations compared to other azole drugs, they are almost identical to those previously described, they exceed the MICs of most fungi for which its use was recommended and they differ depending on the patient's age. The method we describe for antifungal monitoring is simple, robust, and efficient. It simultaneously analyzes azoles and metabolites, and can be used for tailored interventions, achieve exposures associated with therapeutic success, decrease treatment-related toxicity, and help prevent resistance emergence due to continuous azole sub-optimal concentrations. [ABSTRACT FROM AUTHOR]

We compared the antifungal susceptibility of 92 Mucorales isolates obtained by visual inspection and spectrophotometric readings following EUCAST (European Committee on Antimicrobial Susceptibility Testing) testing. Amphotericin B minimum inhibitory concentrations (MICs) were up to 1 mg/l against most isolates and variable among species, except for Cunninghamella bertholletiae. Posaconazole MICs against most isolates were up to 1 mg/l and high against Mucor circinelloides , some Rhizopus arrhizus , and Rhizopus microsporus. Isavuconazole MICs ranged between 1 and 8 mg/l but were invariably >8 mg/l against M. circinelloides and C. bertholletiae. The agreement between MICs obtained by visual endpoint or spectrophotometric readings was moderate and higher when using the ≥90% fungal growth inhibition endpoint. [ABSTRACT FROM AUTHOR]

To describe reasons for initiation and evolution under isavuconazole (ISZ), a 2-year prospective and observational study was performed. Anonymized data collected during the first 3 months of treatment were indications of treatment, efficacy, overall survival (OS), evolution of toxicity markers, and ISZ trough levels. Fifty-one (26 invasive aspergillosis, 16 prophylaxis, and 9 mucormycosis) patients started on isavuconazole. Isavuconazole was initiated upfront in 12/51 cases, especially to avoid toxicities from other antifungals. As second-line therapy (39/51 patients), isavuconazole was mostly initiated after toxicities of the previous treatments (66.7%; 26/39 cases). An improvement in toxicity markers was reported in most patients. However, five patients experienced adverse events. The mean ISZ trough levels measured from 179 samples collected in 37 patients was 3.33 ± 1.64 mg/l. The mean ISZ through levels was significantly lower (P = .003) in alloHSCT recipients (3.10 ± 1.45 mg/l) than in other patients (3.76 ± 1.88 mg/l) but still within the expected range of efficacy. After 12 weeks, the OS was 69.2% (n = 18/26) in the invasive aspergillosis intention-to-treat (ITT) group and 44.4% (n = 4/9) in the mucormycosis ITT group. After 2 years, the OS was respectively 46.2% (n = 12/26) and 33.3% (n = 3/9) in these two groups. Lay Summary: Isavuconazole is commonly prescribed as second-line therapy after the toxicity of a previous treatment. In most cases, an improvement is reported. The well tolerability of isavuconazole was associated with correct blood levels, even in alloHSCT recipients. [ABSTRACT FROM AUTHOR]

Purpose We present the case of a 56-year-old man with stage IV sarcoidosis on veno-venous extracorporeal membrane oxygenation (VV-ECMO) support for the management of respiratory failure receiving treatment with isavuconazole for invasive aspergillosis. Summary VV-ECMO is an increasingly utilized life support therapy for patients with cardiac and/or respiratory failure, but its impact on medication dosing is poorly understood. In our patient with invasive Aspergillus infection receiving VV-ECMO, because of difficulty achieving therapeutic serum concentrations of voriconazole, we administered isavuconazole 372 mg intravenously (IV) every 8 hours for 6 doses followed by 372 mg IV once daily. Isavuconazole has a favorable pharmacokinetic and safety profile compared to other azole antifungal agents, but its high protein binding and lipophilicity raise concerns about drug sequestration in the VV-ECMO circuit. To optimize the efficacy and safety of this treatment, the isavuconazole trough concentration was measured at days 5 and 17, at which time it was 1.7 and 0.7 μg/mL, respectively. The dose was subsequently increased to 744 mg IV once daily, and serum trough concentrations were measured 5 and 8 days after dose adjustment, corresponding to 3.7 and 2.9 μg/mL, respectively. To our knowledge, this is the third report to describe inadequate isavuconazole trough concentrations during VV-ECMO support when utilizing standard doses. Conclusion In the case described here, standard-dose isavuconazole (372 mg every 8 hours for 6 doses followed by 372 mg daily) did not achieve target trough concentrations in a patient receiving concomitant ECMO support. [ABSTRACT FROM AUTHOR]

The in vitro and in vivo efficacy of caspofungin was determined in combination with isavuconazole against Candida auris. Drug–drug interactions were assessed utilizing the fractional inhibitory concentration indices (FICIs), the Bliss independence model and an immunocompromised mouse model. Median planktonic minimum inhibitory concentrations (pMICs) of 23 C. auris isolates were between 0.5 and 2 mg/l and between 0.015 and 4 mg/l for caspofungin and isavuconazole, respectively. Median pMICs for caspofungin and isavuconazole in combination showed 2–128-fold and 2–256-fold decreases, respectively. Caspofungin and isavuconazole showed synergism in 14 out of 23 planktonic isolates (FICI range 0.03–0.5; Bliss cumulative synergy volume range 0–4.83). Median sessile MICs (sMIC) of 14 biofilm-forming isolates were between 32 and >32 mg/l and between 0.5 and >2 mg/l for caspofungin and isavuconazole, respectively. Median sMICs for caspofungin and isavuconazole in combination showed 0–128-fold and 0-512-fold decreases, respectively. Caspofungin and isavuconazole showed synergistic interaction in 12 out of 14 sessile isolates (FICI range 0.023–0.5; Bliss cumulative synergy volume range 0.13–234.32). In line with the in vitro findings, synergistic interactions were confirmed by in vivo experiments. The fungal kidney burden decreases were more than three log volumes in mice treated with combination of 1 mg/kg caspofungin and 20 mg/kg isavuconazole daily; this difference was statistically significant compared with control mice (P  < 0.001). Despite the favorable effect of isavuconazole in combination with caspofungin, further studies are needed to confirm the therapeutic advantage of this combination when treating an infection caused by C. auris. [ABSTRACT FROM AUTHOR]

Voriconazole is frequently discontinued prematurely as primary antifungal prophylaxis (AFP) in allogeneic hematopoietic cell transplant (HCT) recipients due to adverse events. Limited data exists for isavuconazole as AFP. We analyzed adult HCT recipients who received voriconazole or isavuconazole AFP to estimate rate of premature AFP discontinuation, identify risk factors for premature AFP discontinuation, and compare incidence of invasive fungal infection (IFI) and survival at day + 180 post-HCT between patients who received voriconazole/isavuconazole-AFP. This was a propensity score matched cohort analysis of 210 HCT-recipients who received voriconazole-AFP (9/1/2014-12/31/2016; voriconazole-cohort), and 95 HCT-recipients who received isavuconazole-AFP (5/1/2017-10/31/2018; isavuconazole-cohort). AFP discontinuation for any reason prior to completion was defined as "premature". Median (interquartile range, IQR) duration of AFP was longer in the isavuconazole-cohort (94 days, 87–100) vs. the voriconazole-cohort (76 days, 23–94; P -value < 0.0001). Premature AFP discontinuation was more frequent in the voriconazole-cohort (92/210, 43.8%) vs. the isavuconazole-cohort (14/95, 14.7%; P -value < 0.0001). The most common reason for premature discontinuation was biochemical hepatotoxicity (voriconazole-cohort: 48/210, 22.8% vs. isavuconazole-cohort: 5/95, 5.26%; P -value = 0.0002). Transaminase values between baseline and end-of-treatment (EOT) and up to 14 days post-EOT significantly increased in the voriconazole-cohort, but remained unchanged in the isavuconazole-cohort. The incidence of IFI at day + 180 was 2.9% (6/210) and 3.2% (3/95) in the voriconazole-cohort and isavuconazole-cohort, respectively (P -value = 0.881). All-cause mortality at day + 180 was 2.4% (5/210) and 6.3% (6/95) in the voriconazole-cohort and isavuconazole-cohort, respectively (P -value = 0.089). When compared to voriconazole, isavuconazole was a safer and as effective primary AFP during the first 3 months after HCT. Lay Summary When compared to voriconazole, isavuconazole is a safer and as effective primary antifungal prophylaxis during the first 3 months after allogeneic hematopoietic cell transplant, with lower rates of hepatotoxicity, and similar rates of fungal infections and all-cause mortality. [ABSTRACT FROM AUTHOR]

This post hoc analysis of international phase III isavuconazole trials identified 50 patients (90% immunocompromised or diabetic) with invasive fungal sinusitis (88% mucormycetes, Aspergillus) who received isavuconazole as primary (n = 33) or salvage (n = 17) therapy for a median of 82 days (range, 2–882). Overall survival was 82% at day 42 and 70% at day 84. [ABSTRACT FROM AUTHOR]

Background Invasive fungal infections (IFIs) are common following lung transplantation. Isavuconazole is unstudied as prophylaxis in organ transplant recipients. We compared effectiveness and tolerability of isavuconazole and voriconazole prophylaxis in lung transplant recipients. Methods A single-center, retrospective study of patients who received isavuconazole (September 2015–February 2018) or voriconazole (September 2013–September 2015) for antifungal prophylaxis. IFIs were defined by EORTC/MSG criteria. Results Patients received isavuconazole (n = 144) or voriconazole (n = 156) for median 3.4 and 3.1 months, respectively. Adjunctive inhaled amphotericin B (iAmB) was administered to 100% and 41% of patients in the respective groups. At 1 year, 8% of patients receiving isavuconazole or voriconazole developed IFIs. For both groups, 70% and 30% of IFIs were caused by molds and yeasts, respectively, and breakthrough IFI (bIFI) rate was 3%. Outcomes did not significantly differ for patients receiving or not receiving iAmB. Independent risk factors for bIFI and breakthrough invasive mold infection (bIMI) were mold-positive respiratory culture and red blood cell transfusion >7 units at transplant. Bronchial necrosis >2 cm from anastomosis and basiliximab induction were also independent risk factors for bIMI. Isavuconazole and voriconazole were discontinued prematurely due to adverse events in 11% and 36% of patients, respectively (P  = .0001). Most common causes of voriconazole and isavuconazole discontinuation were hepatotoxicity and lack of oral intake, respectively. Patients receiving ≥90 days prophylaxis had fewer IFIs at 1 year (3% vs 9%, P  = .02). IFIs were associated with increased mortality (P  = .0001) and longer hospitalizations (P  = .0005). Conclusions Isavuconazole was effective and well tolerated as antifungal prophylaxis following lung transplantation. [ABSTRACT FROM AUTHOR]

Background Mold-active primary antifungal prophylaxis (PAP) is routinely recommended in neutropenic patients with newly diagnosed acute myeloid leukemia (AML) or high-risk myelodysplastic syndrome (MDS) undergoing remission-induction chemotherapy (RIC). Isavuconazole (ISAV) is an extended spectrum mold-active triazole and has superior tolerability and fewer significant drug–drug interactions compared with other triazoles. Methods In our investigator-initiated, phase 2 trial, treatment-naive adult patients with AML or MDS starting RIC received ISAV per the dosing recommendations in the US label until neutrophil recovery (absolute neutrophil count [ANC] ≥ 0.5 × 109/L) and attainment of complete remission, occurrence of invasive fungal infection (IFI), or for a maximum of 12 weeks. The primary endpoint was the incidence of proven/probable IFI during ISAV PAP and up to 30 days after the last dose. Results Sixty-five of 75 enrolled patients received ISAV PAP (median age, 67 years, median ANC at enrollment, 0.72 × 109/L). Thirty-two patients (49%) received oral targeted leukemia treatments (venetoclax, FTL3 inhibitors). Including the 30-day follow-up period, probable/proven and possible IFIs were encountered in 4 (6%) and 8 patients (12%), respectively. ISAV trough serum concentrations were consistently > 1 µg/mL, showed low intraindividual variation, and were not significantly influenced by chemotherapy regimen. Tolerability of ISAV was excellent, with only 3 cases (5%) of mild to moderate elevations of liver function tests and no QTc prolongations. Conclusions ISAV is a safe and effective alternative for PAP in patients with newly diagnosed AML/MDS undergoing RIC in the era of recently approved or emerging small-molecule antileukemia therapies. Clinical Trials Registration NCT03019939. [ABSTRACT FROM AUTHOR]

Background The survival benefit of combination antifungal therapy for invasive mucormycosis (IM) in patients with hematologic malignancy (HM) and hematopoietic cell transplant (HCT) is not well defined. Methods This multicenter, retrospective study included HM and HCT recipients with proven or probable IM between January 1, 2007 and December 31, 2017 from 10 transplant centers across North America. Results Sixty-four patients with proven (n = 47) or probable (n = 17) IM defined by 2008 European Organization for Research and Treatment of Cancer/Mycoses Study Group (EORTC/MSG) consensus definitions were included. Thirty-nine (61%) were HCT recipients (95% allogeneic). Sites of infection included rhino-orbital-cerebral (33), pulmonary (30%), disseminated (19%), gastrointestinal (3%), and cutaneous (3%). Surgical debridement was performed in 66%. Initial antifungal treatment consisted of the following: lipid formulation of amphotericin B (AmB) alone (44%), AmB + posaconazole (25%), AmB + echinocandin (13%), AmB + isavuconazole (8%), posaconazole alone (5%), and isavuconazole alone (3%). All-cause mortality at 30 days and 1 year were 38% and 66%, respectively. Initial treatment with AmB plus posaconazole or isavuconazole (n = 28) was associated with a trend toward lower treatment failure compared with AmB (n = 21) (42% vs 64%, P  = .136). Conclusions Long-term survival with IM among HM and HCT populations remains poor. However, initial use of AmB + azole in conjunction with surgery may result in less treatment failure. More evidence from prospective controlled studies is needed to confirm this observation. [ABSTRACT FROM AUTHOR]

Treatment options for Exserohilum rostratum meningoencephalitis and other causes of phaeohyphomycosis of the central nervous system (CNS) are limited, while mortality and morbidity remain high. We therefore evaluated isavuconazole, a new antifungal triazole in comparison to liposomal amphotericin B (LAMB), in vitro and in the rabbit model of Exserohilum rostratum meningoencephalitis. We hypothesized that isavuconazole alone or in combination with LAMB or micafungin may be alternative options for treatment of CNS phaeohyphomycosis. We therefore investigated the in vitro antifungal activity of isavuconazole alone or in combination with amphotericin B deoxycholate (DAMB) or micafungin and efficacy of treatment with isavuconazole and LAMB in a rabbit model of experimental E. rostratum meningoencephalitis. Combination checkerboard plates were used to determine the minimum inhibitory concentrations, minimal lethal concentrations, fractional inhibitory concentration indices, and Bliss surface analysis of isavuconazole and amphotericin B deoxycholate (DAMB), either alone or in combination. As there were no in vitro synergistic or antagonistic interactions for either combination of antifungal agents against the E. rostratum isolates, in vivo studies were conducted with isavuconazole and LAMB as monotherapies. Rabbits were divided in following groups: treated with isavuconazole at 60 mg/kg/d (ISAV60), LAMB at 5.0 (LAMB5), 7.5 (LAMB7.5), and 10 mg/kg/d (LAMB10), and untreated controls (UC). In ISAV60-, LAMB5-, LAMB7.5-, and LAMB10-treated rabbits, significant reductions of fungal burden of E. rostratum in cerebral, cerebellar, and spinal cord tissues (P  < 0.01) were demonstrated in comparison to those of UC. These antifungal effects correlated with significant reduction of CSF (1→3)-β-D-glucan levels vs UC (P  < 0.05). These data establish new translational insights into treatment of CNS phaeohyphomycosis. [ABSTRACT FROM AUTHOR]

We determined isavuconazole serum concentrations for 150 UK patients receiving standard isavuconazole dosing regimens, including serial therapeutic drug monitoring for several patients on prolonged therapy. Mean trough isavuconazole concentrations in these patients were virtually identical to those reported previously from clinical trials, although greater variability was seen in patients below 18 years of age. Serial monitoring in patients receiving prolonged therapy suggested gradual, near-linear accumulation of the drug over many weeks. [ABSTRACT FROM AUTHOR]

The incidence of invasive fungal diseases (IFDs) with central nervous system (CNS) involvement is increasing due to the rising numbers of immunocompromised individuals, such as patients receiving chemotherapy, transplantation procedures, or immune-modulating therapies. CNS IFDs cause significant morbidity and mortality, and treatments are complicated by difficulties in identifying fungal pathogens and delivering antifungal agents to the CNS. Isavuconazole is a novel triazole with broad-spectrum activity that has shown good blood–brain barrier penetration in animal models. We present a retrospective analysis of isavuconazole in the treatment of patients with CNS IFDs and who either participated in the phase III VITAL or SECURE clinical trials, or were included in a named-patient program. A total of 36 patients were identified, including 27 patients from the clinical trials. Of these patients, 47.2% had hematologic malignancies, while 13.9% had no identifiable underlying conditions. Mucorales, Aspergillus species, and Cryptococcus species accounted for 30.6%, 22.2%, and 13.9% of infections, respectively. The overall survival rate was 80.6% at day 42 and 69.4% at day 84, and at the end of treatment, a complete or partial clinical response was achieved in 58.3% of patients. Isavuconazole exhibited clinical activity in a variety of CNS IFDs. [ABSTRACT FROM AUTHOR]

Background Isavuconazole (ISA) is an attractive candidate for primary mold-active prophylaxis in high-risk patients with hematologic malignancies or hematopoietic cell transplant (HCT) recipients. However, data supporting the use of ISA for primary prophylaxis in these patients are lacking. Methods We conducted a retrospective review of breakthrough invasive fungal infections (bIFIs) among adult hematologic malignancy patients and HCT recipients who received ≥7 days of ISA primary prophylaxis between 1 September 2016 and 30 September 2018. The incidence of bIFIs in patients receiving ISA was compared to those receiving posaconazole (POS) and voriconazole (VOR) during the same time period. Results One hundred forty-five patients received 197 courses of ISA prophylaxis. Twelve bIFIs (Aspergillus fumigatus [5], Aspergillus species [2], Mucorales [2], Fusarium species [2], and Candida glabrata [1]) occurred, representing 8.3% of patients and 6.1% of courses, after a median duration of 14 days of ISA prophylaxis. All bIFIs occurred during periods of neutropenia. Seven patients (58.3%) died within 42 days of onset of bIFI. In addition, bIFIs complicated 10.2% of ISA, 4.1% of POS, and 1.1% of VOR courses among patients with de novo or relapsed/refractory acute myeloid leukemia during the study period, with invasive pulmonary aspergillosis (IPA) complicating 6.8% of ISA, 1.3% of POS, and zero VOR courses. Conclusions Although ISA has been approved for treatment of invasive Aspergillus and mucormycosis, we observed an increased rate of bIFI, notably IPA, using ISA for primary prophylaxis. These results support the need for further study to determine the role of ISA as primary prophylaxis. [ABSTRACT FROM AUTHOR]

Prolonged courses of isavuconazole (ISA) are increasingly utilized in immunocompromised patients. Toxicities have been reported with long-term use of the other triazoles. We report the first real-life tolerability data in 50 patients with hematologic malignancy receiving ≥6 months of ISA. ISA was well tolerated in our ill patient population. [ABSTRACT FROM AUTHOR]

Background: Isavuconazole is the newest triazole antifungal approved for the treatment of invasive aspergillosis (IA) and invasive mucormycosis in adult patients.Objectives: To characterize the assessment of the blood levels of isavuconazole and their association with efficacy and toxicity.Methods: From January 2017 to May 2018, blood samples obtained from patients receiving isavuconazole were analysed for therapeutic drug monitoring. Factors influencing the blood concentrations of isavuconazole, such as weight, length of treatment, route of administration and results of selected liver function tests, were analysed in univariate and multivariate models. The receiver operating characteristic (ROC) curve was analysed to detect the best cut-off for isavuconazole toxicity.Results: A total of 264 isavuconazole blood concentrations in 19 patients were analysed. The median value of isavuconazole concentration in all patients during the first 30 days of therapy was 3.69 mg/L (range 0.64-8.13 mg/L). A linear increase of 0.032 mg/L (range 0.023-0.041 mg/L) for each day of treatment (P = 0.002) was observed. In multivariate analysis the association between the length of treatment and higher levels of isavuconazole (P < 0.001) and higher serum GGT and lower isavuconazole levels (P = 0.001) was confirmed. Adverse events, mainly gastrointestinal, were reported in six patients (31.6%). Based on time-dependent and fixed-time ROC curve analysis, 4.87 mg/L and 5.13 mg/L, respectively, were the identified thresholds for toxicity.Conclusions: Isavuconazole was efficacious and well tolerated. Side effects, mainly gastrointestinal, were associated with prolonged administration and high serum levels. [ABSTRACT FROM AUTHOR]

Objectives To evaluate the in vitro interactions of isavuconazole with immune suppressors (tacrolimus, cyclosporin A or sirolimus) against 30 Mucorales isolates belonging to the most common species responsible for mucormycosis in humans (Rhizopus arrhizus , Rhizopus delemar , Rhizopus microsporus , Lichtheimia corymbifera , Lichtheimia ramosa , Mucor circinelloides and Rhizomucor pusillus). Methods In vitro interaction was evaluated by a microdilution chequerboard technique. Results Combination of isavuconazole with tacrolimus, cyclosporin A or sirolimus, was synergistic for 50%, 46% and 7% of the isolates, respectively. Antagonistic interaction was observed for 4% of the isolates for the combination with cyclosporin A (one R. arrhizus isolate) and for 32% of the isolates for the combination with sirolimus (six R. arrhizus isolates and three R. pusillus isolates). Conclusions These in vitro data show that calcineurin inhibitors are more likely than inhibitors of the mTOR pathway to enhance the activity of isavuconazole against Mucorales. These in vitro results warrant further animal experiments. [ABSTRACT FROM AUTHOR]

Background Isavuconazole was compared to caspofungin followed by oral voriconazole in a Phase 3, randomized, double-blind, multinational clinical trial for the primary treatment of patients with candidemia or invasive candidiasis. Methods Adult patients were randomized 1:1 to isavuconazole (200 mg intravenous [IV] three-times-daily [TID] for 2 days, followed by 200 mg IV once-daily [OD]) or caspofungin (70 mg IV OD on day 1, followed by 50 mg IV OD [70 mg in patients > 80 kg]) for a maximum of 56 days. After day 10, patients could switch to oral isavuconazole (isavuconazole arm) or voriconazole (caspofungin arm). Primary efficacy endpoint was successful overall response at the end of IV therapy (EOIVT) in patients with proven infections who received ≥1 dose of study drug (modified-intent-to-treat [mITT] population). The pre-specified noninferiority margin was 15%. Secondary outcomes in the mITT population were successful overall response at 2 weeks after the end of treatment, all-cause mortality at days 14 and 56, and safety. Results Of 450 patients randomized, 400 comprised the mITT population. Baseline characteristics were balanced between groups. Successful overall response at EOIVT was observed in 60.3% of patients in the isavuconazole arm and 71.1% in the caspofungin arm (adjusted difference -10.8, 95% confidence interval -19.9–-1.8). The secondary endpoints, all-cause mortality, and safety were similar between arms. Median time to clearance of the bloodstream was comparable between groups. Conclusions This study did not demonstrate non-inferiority of isavuconazole to caspofungin for primary treatment of invasive candidiasis. Secondary endpoints were similar between both groups. Clinical Trials Registration NCT00413218. [ABSTRACT FROM AUTHOR]

Isavuconazole is a new triazole with an expanded-spectrum and potent activity against moulds and yeasts. It has been authorized for use in adults for the treatment of invasive aspergillosis and for mucormycosis. The only commercially available isavuconazole susceptibility test is the minimum inhibitory concentration (MIC) strip isavuconazole test. The objective of this study was to assess the in vitro activity of isavuconazole using gradient concentration MIC strips, compared with the EUCAST broth microdilution reference method. A total of 147 clinically relevant fungal isolates comprising 120 Aspergillus sp. and 27 Scedosporium apiospermum complex were tested for susceptibility to isavuconazole using the EUCAST broth microdilution method and by the MIC strip isavuconazole test. The percent essential agreement between the two methods was calculated within a 1-fold dilution. The geometric means for the MICs using the EUCAST reference methods and the strip test were respectively: 0.60 mg/l and 0.65 mg/l for A. fumigatus, 0.70 mg/l and 0.77 mg/l for A. flavus, 1.50 mg/l and 1.25 mg/l for A. niger, 0.41 mg/l and 0.38 mg/l for A. terreus, 1.22 mg/l and 1.08 mg/l for S. apiospermum complex. The isavuconazole MIC strips showed good agreement with the EUCAST reference method. Isavuconazole MIC strips could be useful for susceptibility testing of Aspergillus sp. and S. apiospermum complex. [ABSTRACT FROM AUTHOR]

Objectives: This analysis evaluated the variability of isavuconazole plasma concentrations between subjects and between sampling times, and assessed their relationship to outcomes for subjects with invasive fungal disease (IFD) in the SECURE trial.Methods: Isavuconazole-treated subjects received 372 mg of isavuconazonium sulphate (corresponding to 200 mg of isavuconazole) three times daily for 2 days, then once daily. Plasma samples were collected after day 4 and analysis sets were constructed as follows: analysis set 1 included all samples from subjects with proven/probable/possible IFD who received ≥1 dose of isavuconazole; analysis set 2 included samples from subjects in analysis set 1 who had provided >1 sample; and analysis set 3 included samples from subjects in analysis set 1 with proven/probable invasive aspergillosis. Assessments included overall distributions of plasma concentrations and variability between samples (analysis sets 1 and 2) as well as relationships to outcomes [all-cause mortality (day 42), overall response (end of treatment) and treatment-emergent adverse events; analysis sets 1 and 3].Results: Analysis sets 1, 2 and 3 included samples from 160, 97 and 98 subjects, respectively. Trough concentrations for each were distributed similarly [mean (SD): 3406.6 (1511.5), 3495.6 (1503.3) and 3368.1 (1523.2) ng/mL, respectively]. The mean coefficient of variation between samples in analysis set 2 was 23.2%; differences between concentrations in first samples and subsequent samples were <2-fold for 85/97 subjects. In quartiles of subject data, no concentration-dependent relationships were observed for efficacy or safety.Conclusions: Plasma concentrations of isavuconazole were reasonably consistent between subjects and sampling times, and were not associated with differences in outcomes. [ABSTRACT FROM AUTHOR]

The article offers insights about the strategy needed to understand the value of antifungal prophylaxis among patients with hematologic malignancy. A comparison between the efficacy of posaconazole and fluconazole or itraconazole is highlighted. Several drawbacks to posaconazole include strong CYP3A4 inhibition, side effect profile and possible liver toxicity. Specifically, one study examined the efficacy of isavuconazole as antifungal prophylaxis in patients with acute myeloid leukemia.

Mucormycosis is a life-threatening infection. This is the first report of transdiaphragmatic mucormycosis in a series of 3 patients. We observed this phenomenon in 11% of patients. Clinicians should be aware of this possibly underreported entity, and as a consequence we envision more comprehensive imaging studies in patients with mucormycosis. [ABSTRACT FROM AUTHOR]

Coccidioidomycosis remains a significant clinical problem with substantial morbidity and mortality. The vast majority of infections are asymptomatic and the need for early primary therapy remains controversial. The use of triazole antifungals has improved tolerability of therapy but concerns about acute and long-term toxicities among available agents limit their use. In addition, recent findings of decreased in vitro fluconazole susceptibility to as many as 37% of Coccidioides spp. isolates raises concerns regarding optimal therapy for these infections as fluconazole is commonly used for therapy including central nervous system disease. Thus, new agents from novel antifungal classes are currently in preclinical and clinical development aimed at reducing toxicity and improving outcomes of these serious infections. [ABSTRACT FROM AUTHOR]

Although the widespread use of mold-active agents (especially the new generation of triazoles) has resulted in reductions of documented invasive mold infections (IMIs) in patients with hematological malignancies and allogeneic hematopoietic stem cell transplantation (HSCT), a subset of such patients still develop breakthrough IMIs (bIMIs). There are no data from prospective randomized clinical trials to guide therapeutic decisions in the different scenarios of bIMIs. In this viewpoint, we present the current status of our understanding of the clinical, diagnostic, and treatment challenges of bIMIs in high-risk adult patients with hematological cancer and/or HSCT receiving mold-active antifungals and outline common clinical scenarios. As a rule, managing bIMIs demands an individualized treatment plan that takes into account the host, including comorbidities, certainty of diagnosis and site of bIMIs, local epidemiology, considerations for fungal resistance, and antifungal pharmacological properties. Finally, we highlight areas that require future investigation in this complex area of clinical mycology. [ABSTRACT FROM AUTHOR]

We retrospectively assessed breakthrough invasive fungal infections (b-IFIs) in 100 consecutive patients with leukemia receiving single-agent isavuconazole; 13 had documented b-IFIs (candidiasis in 6, mucormycosis in 4). All b-IFIs were observed in patients with prolonged neutropenia and active leukemia. [ABSTRACT FROM AUTHOR]

No clinical trials for histoplasmosis have been performed with the newer azoles, leaving itraconazole as the azole of choice. In vitro studies suggest that Histoplasma capsulatum from patients that relapse on fluconazole has higher minimum inhibitory concentrations (MICs) to fluconazole and voriconazole but not itraconazole and posaconazole. The newest azole, isavuconazole, shares structural similarity to voriconazole, but to date nobody has explored emergence of resistance. In vitro susceptibilities to isavucoanzole and fluconazole were performed on previously obtained isolates from the patients who relapsed on fluconazole therapy. Susceptibilities were determined by NCCLS method M27A developed for yeasts, as modified for H. capsulatum. The change in the MIC from the primary to the relapse isolate was tested using Wilcoxon Rank-Sum for paired data. Among the primary isolates, the median MICs were 1.0 (range 0.25 to 4.0) μg/ml for fluconazole and ≤0.007 (range ≤0.007 to 0.015) μg/ml for isavuconazole. In the group of relapsed isolates, the median MICs rose to 8.0 (range 0.25 to 64.0) μg/ml for fluconazole and remained unchanged at ≤0.007 (range ≤0.007 to 0.015) μg/ml for isavuconazole (P <.001). Only one isolate exhibited a nonsignificant increase in MIC to isavuconazole. Histoplasma isolates from patients who relapsed on fluconazole did not have an elevation in MICs to isavuconazole. This differs from the results previously seen with voriconazole and suggests that despite a closer structural similarity to voriconazole than itraconazole and posaconazole, isavuconazole has a higher barrier to resistance and may be effective as therapy for histoplasmosis. [ABSTRACT FROM AUTHOR]

Background: Historically, baseline neutropenia and lack of neutrophil recovery have been associated with poor outcomes in invasive aspergillosis (IA). It is unclear how treatment with the new Aspergillus-active triazoles isavuconazole and voriconazole affects outcomes in neutropenic patients with IA.Methods: A post hoc analysis of the Phase 3 SECURE trial assessed patients with neutropenia (neutrophil count <0.5 × 109/L for >10 days at baseline) with IA (proven/probable) who had received either isavuconazole or voriconazole. The primary endpoint was all-cause mortality (ACM) through day 42. ACM in patients with resolved versus unresolved neutropenia at day 7 and overall success at end of treatment (EOT) were also assessed.Results: One hundred and forty-two patients with neutropenia and IA were included (isavuconazole n = 78, voriconazole n = 64). ACM through day 42 (primary endpoint), day 7 and EOT were higher for patients with unresolved versus resolved neutropenia at each timepoint (day 42, unresolved: 45.0% isavuconazole, 45.2% voriconazole; resolved: 5.0% isavuconazole, 5.9% voriconazole; day 7, unresolved: 31.0% isavuconazole, 29.8% voriconazole; resolved: 5.0% isavuconazole, 5.9% voriconazole; EOT, unresolved: 48.6% isavuconazole, 36.4% voriconazole; resolved: 5.0% isavuconazole, 14.3% voriconazole). ACM was significantly higher for isavuconazole-treated patients with unresolved versus resolved neutropenia (day 7, P = 0.031; day 42, P < 0.001; EOT, P < 0.001). In voriconazole-treated patients, ACM was significantly higher among patients with unresolved versus resolved neutropenia at day 42 (P = 0.002) and numerically higher at day 7 and EOT (P > 0.05 for both).Conclusions: Isavuconazole had comparable efficacy and safety to voriconazole in neutropenic patients with IA. Resolution of neutropenia was associated with improved outcomes. [ABSTRACT FROM AUTHOR]

Introduction: Isavuconazole is a new triazole approved for the treatment of invasive aspergillosis. We investigated isavuconazole MIC distributions, isavuconazole MIC correlations with those of other azoles and pharmacodynamics of isavuconazole in low-level resistant Aspergillus fumigatus isolates.Methods: Isavuconazole, voriconazole, itraconazole and posaconazole susceptibility of 487 clinical A. fumigatus isolates was determined by EUCAST broth microdilution methodology. Using an in vivo estimation of the pharmacodynamic target and a previously published pharmacokinetic model, the probability of target attainment (PTA) was determined for a range of isavuconazole MICs using three dosing regimens (I, 200 mg once daily; II, 300 mg once daily; and III, 400 mg once daily).Results: Two hundred and seventy-nine of 487 isolates were phenotypically WT based on epidemiological cut-offs of voriconazole, itraconazole and posaconazole. Twenty-five of 279 phenotypically WT isolates and 196 of 208 non-WT isolates were classified as isavuconazole resistant based on the EUCAST breakpoint of 1 mg/L. Isavuconazole MICs showed very high correlation with voriconazole MICs, but moderate and low correlation with itraconazole and posaconazole MICs. The PTA for isolates with an isavuconazole MIC of 1 mg/L was 92%-99% for 90% effective concentration (EC90) for the three dosing regimens. For isolates with an MIC of 2 mg/L the PTA decreased to 64%-92% for EC90.Conclusions: Our study indicated that isavuconazole and voriconazole MICs are highly correlated and that high-dose isavuconazole treatment might be an option in patients infected with an A. fumigatus isolate with an isavuconazole MIC of 2 mg/L. [ABSTRACT FROM AUTHOR]

Combination therapy may be an alternative therapeutic approach for difficult-to-treat Candida infections with the aim of increasing efficacy of antifungal therapy. Whether isavuconazole, an extended-spectrum triazole, possesses synergistic activity in combination therapy with echinocandins or polyenes for the treatment of invasive candidiasis has not been studied. We used Bliss independence drug interaction analysis and timekill assays to examine the in vitro interactions of isavuconazole with amphotericin B or micafungin, an echinocandin, against strains of Candida albicans, Candida parapsilosis, Candida glabrata, Candida tropicalis, and Candida krusei. The Bliss independence-based drug interactions modeling showed that the combination of isavuconazole and micafungin resulted in synergistic interactions against C. albicans, C. parapsilosis, and C. krusei. The degree of synergy ranged from 1.8% to 16.7% (mean %ΔE value) with the highest synergy occurring against C. albicans (ΣSYN% = 8.8%110%). Time-kill assays showed that the isavuconazole-micafungin combination demonstrated concentrationdepended synergy against C. albicans and C. parapsilosis. The combined interaction by Bliss analysis between isavuconazole and amphotericin B was indifferent for C. albicans, C. parapsilosis, and C. tropicalis while for C. glabrata was antagonistic (-2% to -6%) and C. krusei synergistic (3.4% to 7%). The combination of isavuconazole-amphotericin B by time-kill assay was antagonistic against C. krusei and C. glabrata. Collectively, our findings demonstrate that combinations of isavuconazole andmicafungin are synergistic against Candida spp., while those of isavuconazole and amphotericin B are indifferent in vitro. [ABSTRACT FROM AUTHOR]

Background. The ability to make early therapeutic decisions when treating invasive aspergillosis using changes in biomarkers as a surrogate for therapeutic response could significantly improve patient outcome. Methods. Cox proportional hazards model and logistic regression were used to correlate early changes in galactomannan index (GMI) to mortality and overall response, respectively, from patients with positive baseline GMI (≥0.5) and serial GMI during treatment from a phase 3 clinical trial for the treatment of invasive mold disease. Pharmacokinetic/pharmacodynamic (PK/PD) analysis in patients with isavuconazole plasma concentrations was conducted to establish the exposure necessary for GMI negativity at the end of therapy. Results. The study included 158 patients overall and 78 isavuconazole patients in the PK/PD modeling. By day 7, GMI increases of >0.25 units from baseline (3/130 survivors; 9/28 who died) significantly increased the risk of death compared to those with no increase or increases <0.25 (hazard ratio, 9.766; 95% confidence interval [CI], 4.356-21.9; P < .0001). For each unit decrease by day 7 from baseline, the odds of successful therapy doubled (odds ratio, 2.154; 95% CI, 1.173-3.955). An area under the concentration-versus-time curve over half-maximal effective concentration (AUC:EC50) of 108.6 is estimated to result in a negative GMI at the end of isavuconazole therapy. Conclusions. Early trends in GMI are highly predictive of patient outcome. GMI increases by day 7 could be considered in context of clinical signs to trigger changes in treatment, once validated. Our data suggest that this improves survival by 10-fold and positive outcome by 3-fold. These data have important implications for individualized therapy for patients and clinical trials. Clinical Trials Registration. NCT00412893. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Objective To review the place in therapy of isavuconazole, the active metabolite of isavuconazonium sulfate, via a review of the available literature on drug chemistry, spectrum of activity, pharmacokinetic/pharmacodynamic profile and trials assessing clinical efficacy and safety. Methods Relevant data, original research articles and reviews, were gathered primarily through the use of a PubMed database search. The search was conducted without date restrictions in order to collect both historical and recent data regarding isavuconazole. Key findings Isavuconazole is a triazole currently approved not only for use in invasive aspergillosis and mucormycosis but also has demonstrable activity against Candida species and other common fungal pathogens. This drug has features which make it more clinically appealing compared to other azoles with similar indications. In specific, isavuconazole does not require a cyclodextrin vehicle due to its water solubility, and at present, does not require therapeutic drug monitoring. Moreover, isavuconazole has displayed improved safety and tolerability compared to voriconazole. Available data from Phase III clinical trials shows isavuconazole to be a possible therapeutic option to currently available therapies for which it is approved; however, clinical conclusions should be reserved until results have been published and more data from clinical use is reported. Conclusions Isavuconazole is a new triazole with broad-spectrum antifungal activity including invasive aspergillosis and mucormycosis. [ABSTRACT FROM AUTHOR]

Isavuconazole is a new extended-spectrum triazole with activity against yeasts, molds, and dimorphic fungi. It is approved for the treatment of invasive aspergillosis and mucormycosis. Advantages of this triazole include the availability of a water-soluble intravenous formulation, excellent bioavailability of the oral formulation, and predictable pharmacokinetics in adults. A randomized, double-blind comparison clinical trial for treatment of invasive aspergillosis found that the efficacy of isavuconazole was noninferior to that of voriconazole. An open-label trial that studied primary as well as salvage therapy of invasive mucormycosis showed efficacy with isavuconazole that was similar to that reported for amphotericin B and posaconazole. In patients in these studies, as well as in normal volunteers, isavuconazole was well tolerated, appeared to have few serious adverse effects, and had fewer drug-drug interactions than those noted with voriconazole. As clinical experience increases, the role of this new triazole in the treatment of invasive fungal infections will be better defined. [ABSTRACT FROM AUTHOR]

Objectives: The aim of the present study was to evaluate and assess the in vitro activity of eight drugs, including the new azole isavuconazole, against 81 strains representing 13 species of the Fusarium fujikuroi species complex. Methods: A total of 81 Fusarium spp. isolates, within the F. fujikuroi species complex, were identified by molecular methods and tested according to CLSI M38-A2. Eight antifungal compounds, including the new azole isavuconazole, were tested. Isolates were selected to represent the widest variety of geographical regions and to include clinical as well as environmental strains. Results: Susceptibility profiles differed between and within species, with Fusarium verticillioides showing the lowest MICs and Fusarium nygamai the highest MICs. Amphotericin B was the most active drug, followed by voriconazole, posaconazole, isavuconazole and natamycin. The remaining antifungals (fluconazole, itraconazole and micafungin) showed poor activity with MIC/minimum effective concentration values of ≥32, ≥16 and >8 mg/L, respectively. Conclusions: Resistance patterns in the F. fujikuroi species complex are species specific and therefore identification down to species level is important for the choice of antifungal treatment. [ABSTRACT FROM AUTHOR]

The in vitro activities of eight antifungal agents were determined against clinical ( n == 63 genotype A, n == 3 genotype B) and environmental ( n == 2 genotype A, n == 13 genotype B) strains of Exophiala dermatitidis. The resulting MIC90s for all strains ( N == 81) were, in increasing order, as follows: posaconazole, 0.125 μg/ml; itraconazole, 0.25 μg/ml; voriconazole, 0.5 μg/ml; amphotericin B, 0.5 μg/ml; isavuconazole, 1 μ/ml; caspofungin, 8 μg/ml; anidulafungin, 8 μg/ml and fluconazole, 16 μg/ml. There were no significant differences in the patterns of susceptibility between genotypes A and B, environmental and clinical strains, isolates recovered from cutaneous and deep locations and strains from different geographical areas ( P > 0.05). The difference in the MIC90s between each of these groups was not more than one dilution. The present study demonstrated that, based on in vitro activity, posaconazole and itraconazole have the highest activity against this fungus. In addition, voriconazole and the experimental broad-spectrum antifungal triazole, isavuconazole, both of which are available as intravenous preparations, have adequate activity against E. dermatitidis. However, in vivo efficacy remains to be determined. [ABSTRACT FROM AUTHOR]

We studied the serotypes, mating-types, AFLP genotypes, and antifungal susceptibility of 58 Cryptococcus neoformans strains causing 56 episodes of cryptococcosis in 55 patients over an 18-year period in a single institution. The underlying conditions of the patients were classified as HIV infection ( n = 48) or non-HIV-related immunodeficiency ( n = 7). Serotype A ( n = 34; 58.9%) predominated, but serotype AD was involved in 23.2% of episodes. Most of the episodes were caused by mating-type α ( n = 41; 73.2%) or α/ a strains ( n = 12; 21.5%). The most common genotype was AFLP1 ( n = 26; 44.8%), followed by AFLP3 ( n = 21; 36.2%), and AFLP2 ( n = 11; 19.0%). In two different patients, we showed the coexistence of different serotypes and/or genotypes in the same episode (AFLP1 and 3). The new triazoles voriconazole, posaconazole and isavuconazole showed high and similar antifungal activity (MICs ≤ 0.125 μg/ml). Fluconazole also had good antifungal activity, but two strains from patients with HIV-infections had an MIC of 16 μg/ml (3.4%). However, these two isolates remained very susceptible to the new triazoles (MICs ≤ 0.062 μg/ml). The remaining strains always showed MICs ≤ 8 μg/ml. [ABSTRACT FROM AUTHOR]

The in vitro activity of isavuconazole was compared to those of amphotericin B, fluconazole, itraconazole, voriconazole, posaconazole, and ravuconazole against 300 clinical isolates of Pseudallescheria boydii, Paecilomyces lilacinus, Fusarium spp., Bipolaris spicifera, Curvularia lunata, Alternaria alternata, Exophiala spp., Rhizopus arrhizus, Mucor circillenoides, Absidia corymbifera, Blastomyces dermatitidis, Histoplasma capsulatum and Coccidioides posadasii. MICs were determined by a broth macrodilution method based on the CLSI M38-A procedure. The triazoles were relatively uniform in that they showed strong in vitro inhibitory activity against most of the tested fungi. In vitro activity was variable with strains of P. lilacinus while with Fusarium spp., the triazoles were found to have limited in vitro activity and amphotericin B was moderately active. The results suggest that isavuconazole is a broad-spectrum antifungal agent, effective against a wide range of moulds in vitro. [ABSTRACT FROM AUTHOR]

Background Isavuconazole is an azole antifungal with in vitro activity against various fungi, including Candida spp, Aspergillus , and Mucormycetes. Currently, isavuconazole is FDA approved for the treatment of invasive aspergillosis and mucormycosis; however, there remains limited data to support prophylaxis use. Compared with other first-line azoles, isavuconazole's broad spectrum of activity, favorable safety profile, and oral bioavailability makes it an attractive antifungal option. In July 2017, isavuconazole was added to our hospital formulary as a restricted antimicrobial. Since then, we have seen increased use for both prophylaxis and treatment of invasive fungal infections. Methods A single-center, retrospective chart review was conducted on adult patients who received at least 1 dose of isavuconazole at The Mount Sinai Hospital between July 1, 2017 and December 31, 2018. The electronic medical record was utilized to collect information on therapeutic indication, dosing, formulation, duration, reasons for switching to isavuconazole, prior antifungals, and proven or probable breakthrough invasive fungal infections (bIFIs) based on EORTG/MTG definitions. Results 54 patients received 61 courses of isavuconazole. Reasons for switching to isavuconazole are described in Table 1. Eleven patients received inappropriate intravenous formulations and 14% of orders were prescribed isavuconazole without a loading dose (Table 2). We identified 4 proven/probable bIFIs, representing 7.4% of patients and 6.6% of courses (Table 3). All patients died within 60 days of bIFI onset. Conclusion Since its addition to hospital formulary, we have observed varying isavuconazole prescribing practices, highlighting the need for improved antifungal stewardship. Rates of bIFIs on isavuconazole were lower than previously reported studies. Additional studies are needed to provide guidance on isavuconazole use and determine its role as prophylaxis therapy. Disclosures All authors: No reported disclosures. [ABSTRACT FROM AUTHOR]

Background Disseminated fusariosis in patients with hematological malignancies is a frequently fatal and emerging invasive mycosis. Fusarium spp. are often resistant to safely achievable concentrations of mould active triazoles and amphotericin B. We aimed to determine the efficacy of isavuconazonium sulfate (ISA) alone or in combination with micafungin (MICA) in a murine model of disseminated fusariosis caused by Fusarium solani. Methods Groups of five 5-week-old Swiss Webster female mice, 20–22 g, were rendered neutropenic by intraperitoneal (IP) injection of cyclophosphamide at 200 mg/kg on day −2 and 150 mg/kg on day +3. Mice were infected with 5 × 10E5 CFU F. solani intravenously (IV) via the lateral tail vein on day 0. To prevent bacterial infection, ceftazidime was administered 50 mg/kg/day IP. Therapy began 18 h post-challenge for 6 days. MICA was given at dosages of 10, 5, 2.5 and 1.25 mg/kg IP Q12h combined with ISA 14 mg/kg/day IP. Six groups of mice received ISA orogastrically (OG) Q8h, Q12h and Q24h at 224 mg/kg alone or combined with MICA at 10 mg/kg Q12h IP. Kaplan–Meier survival analysis was performed. Results ISA at 14 mg/kg Q12h combined with 10 mg/kg MICA doses resulted in improved survival but with no significant reduction of residual fungal burden compared with monotherapy or other ISA/MICA dose combinations. Improved survival with dose-escalated oral monotherapy was observed at ISA 224 mg/kg Q12h (50% survival) and Q8h OG (60%) compared with other monotherapy or combination, or untreated groups (18–20%). The residual fungal burden in kidney between monotherapy and combination therapy groups was 5.81 10Log (untreated), 4.03 10Log (ISA 224 mg/kg, OG Q12h), 5.19 10Log (ISA 224 mg/kg Q12h + MICA 10 mg/kg, Q12h), 4.67 10Log (ISA 224 mg/kg, Q24h), and 4.82 10Log (ISA 224 mg/kg Q24h + MICA 10 mg/kg, Q12h). Conclusion High doses of isavuconazole (exceeding currently approved human dosages) in combination with micafungin improved survival in experimental murine disseminated fusariosis. Given the excellent safety profile of ISA, exploration of higher dosages that are necessary to achieve this antifungal effect is warranted for successful management of disseminated fusariosis. Disclosures All authors: No reported disclosures. [ABSTRACT FROM AUTHOR]

Background Candida auris outbreak continues unabated in New York with the current case counts exceeding 300 patients. We used a modification of standard CLSI broth microdilution method (BMD) if two-drug combinations are efficacious against C. auris isolates with high-resistance to fluconazole (FZ, MIC50 >256 mg/L), and variable resistance to other broad-spectrum antifungal drugs. Methods BMD plates were custom-designed and quality controlled by TREK Diagnostic System. The combination tests of 15 drug-resistant C. auris involved microtiter wells with the initial 144 two-drug combinations and their two-fold dilutions (1/2–1/32) to get 864 two-drug combinations finally. We utilized MIC100 endpoints for the drug combination readings as reported earlier for the intra- and inter-laboratory agreements obtained against Candida species and Aspergillus fumigatus (Antimicrob Agents Chemother. 2015. 59:1759–1766). We also tested minimum fungicidal concentrations (MFC). Results We tested all possible 864 two-drug antifungal combinations for nine antifungal drugs in use to yield 12,960 MIC100 readings, and MFC readings for 15 C. auris isolates. Flucytosine (FLC) at 2.0 mg/L potentiated most successful combinations with other drugs. Micafungin (MFG), Anidulafungin (AFG), Caspofungin (CAS) at individual concentrations of 0.25 mg/L combined well with FLC (2.0 mg/L) to yield MIC100 for 14, 13, and 12 of 15 C. auris isolates tested, respectively. MFG/FLC combination was also fungicidal for 4 of 15 isolates. AMB / FLC (0.25/1.0 mg/L) yielded MIC100 for 13 isolates and MFC for three test isolates. Posaconazole (POS), and Isavuconazole (ISA) and Voriconazole (VRC) also combined well with FLC (0.25/2.0 mg/L) to yield MIC100 for 12, 13, and 13 isolates, respectively. POS/FLC combination was fungicidal for three isolates. Conclusion We identified seven two drug-combinations of antifungals efficacious against drug-resistant C. auris strains. The modified BMD combination susceptibility testing could be used by the clinical laboratories to assist providers with the selection of optimal treatment for C. auris candidemia. Disclosures All authors: No reported disclosures. [ABSTRACT FROM AUTHOR]

Background Mucormycosis is a life-threatening infection that predominantly occurs in immunocompromised hosts. The antifungal APX001A (manogepix) inhibits Gwt1, an enzyme required for the conserved glycosylphosphatidyl inositol (GPI) post-translational modification in eukaryotes. We previously reported the activity of APX001 (fosmanogepix, the prodrug of APX001A) against Rhizopus delemar (minimum effective concentration [MEC] = 0.25 µg/mL). Here we assessed the activity against R. oryzae, which has an elevated MEC value. Methods R. oryzae 99–892 MIC and MEC values were 0.125 µg/mL and 4.0 µg/mL for isavuconazole (ISAV) and APX001A, respectively. ICR mice were immunosuppressed with cyclophosphamide (200 mg/kg) and cortisone acetate (500 mg/kg) on Days -2, +3, and +8 relative to intratracheal infection with 2.5 × 105 cells of R. oryzae 99–892. For survival studies, treatment with 104 mg/kg APX001 was compared with ISAV (110 mg/kg TID). Oral treatment started on Day +1 through Day +7, relative to infection for survival studies, and through Day +4 for tissue fungal burden studies (assessed by conidial equivalent [CE] using qPCR). Placebo mice received vehicle control. To extend the half-life of APX001, mice were administered 50 mg/kg of the cytochrome P450 inhibitor 1-aminobenzotriazole (ABT) 2 h prior to APX001 administration. Results APX001 and ISAV equally prolonged median survival time of mice (n = 20) vs. placebo (12 and 14 days for APX001 and ISAV, respectively, vs. 8 days for placebo). Furthermore, APX001 and ISAV treatment both resulted in 30% 21-day survival vs. 0% survival of placebo mice (P < 0.05 by log-rank test). Both drug treatments resulted in ~1.5 log10 reduction in lung and brain CE vs. placebo-treated mice (n = 10, P < 0.005 by Wilcoxon rank-sum test). Conclusion Despite a higher MEC value, APX001 showed significant efficacy against R. oryzae that was as protective as ISAV in immunosuppressed mice. Given the previously reported activity of APX001 against a strain of R. delemar with a lower MEC value,APX001 has now been shown to be efficacious against both species of Rhizopus , which together are responsible for ~60–70% of isolates causing lethal mucormycosis. Thus, continued investigation of APX001 against mucormycosis is warranted. Disclosures All authors: No reported disclosures. [ABSTRACT FROM AUTHOR]

Background IFI is a significant complication following lung transplant (LT). VOR was universal antifungal px in our LT program from 2004 to October 2015, at which time px was changed to ISA. We compared the efficacy and tolerability of VOR vs. ISA px in LTR. Methods We reviewed all LTR from September 2013 to February 2018 who received VOR or ISA Px. The standard duration of px was 3 or 4 months following basiliximab and alemtuzumab induction, respectively. All patients were followed for ≥1 years post-Tx. IFI was defined by revised EORTC/MSG criteria. Results In total, 310 LTR were included, 149 and 161 of whom received ISA and VOR px, respectively. There was no difference in demographics, underlying diseases, single vs. double LT, or induction therapy (alemtuzumab vs. basiliximab) between the 2 groups. At 1-year after LT, 9% (14) and 8% (13) of patients in ISA and VOR groups developed IFI, respectively (P = 0.5). 5% (7) and 3% (5) of patients developed breakthrough (BT) IFI during ISA and VOR px, respectively (P = 0.6; Figure 1, P = 0.4, Kaplan-–Meier). ISA BT included pneumonia (PNA, 2), endobronchial IFI (2), mediastinitis (1), chest wall IFI (1), and candidemia (1). ISA BT patients were infected with Aspergillus fumigatus (3; 2 with ISA MIC = 0.5 µg/mL, 1 MIC = 1 µg/mL), black mould (1), and yeasts (3; 2 C. glabrata , 1 C. albicans). VOR BT IFI included PNA (2), endobronchial IFI (1), empyema (1), and chest wall IFI (1). VOR BT IFIs were due to A. ustus , A. niger , A. lentulus , black mould, and Rhizopus spp (1 each). All Aspergillus VOR BT isolates exhibited VOR MIC ≥2 µg/mL. Patients with IFI were more likely to have positive pre-LT respiratory fungal culture (P = 0.01) and grade ≥3 ischemic reperfusion injury (IRI) post-LT (P = 0.01). VOR and ISA were prematurely discontinued in 53% (85) and 14% (21) of patients due to adverse events, respectively (P < 0.0001). Hepatotoxicity was more common with VOR (22%, 35) than ISA (5%, 7) (P < 0.0001). IFI was an independent risk factor for death at 1 year (Figure 2, P < 0.0001, Kaplan–Meier). Conclusion ISA was as effective as VOR in preventing IFI in LTR, and significantly better tolerated. Pre-LT fungal culture positivity and grade ≥3 IRI post-LT were risk factors for the development of IFI. IFI within 1-year post-LT had a significant impact on mortality Disclosures Fernanda P. Silveira, MD, MS, FIDSA, Ansun: Grant/Research Support; Qiagen: Grant/Research Support; Shire: Grant/Research Support; Whiscon: Grant/Research Support. [ABSTRACT FROM AUTHOR]

The article discusses the in vitro activities of antifungal drugs against an agent of fatal brain infection called Rhinocladiella mackenziei. It states that cerebral phaeohyphomycosis, a rare disease with high mortality, is usually caused by Exophiala dermatitidis, Cladophialophora bantiana and Rhinocladiella mackenziei. It notes that the new drug isacunazole may be promising alternative for this indication, but its activity against R. mackenziei should be confirmed first in animal models.