Breakthrough Fungal Infections Research Articles

Antifungal heteroresistance causes prophylaxis failure and facilitates breakthrough Candida parapsilosis infections.

Breakthrough fungal infections in patients on antimicrobial prophylaxis during allogeneic hematopoietic cell transplantation (allo-HCT) represent a major and often unexplained cause of morbidity and mortality. Candida parapsilosis is a common cause of invasive candidiasis and has been classified as a high-priority fungal pathogen by the World Health Organization. In high-risk allo-HCT recipients on micafungin prophylaxis, we show that heteroresistance (the presence of a phenotypically unstable, low-frequency subpopulation of resistant cells (~1 in 10,000)) underlies breakthrough bloodstream infections by C. parapsilosis. By analyzing 219 clinical isolates from North America, Europe and Asia, we demonstrate widespread micafungin heteroresistance in C. parapsilosis. Standard antimicrobial susceptibility tests, such as broth microdilution or gradient diffusion assays, which guide drug selection for invasive infections, fail to detect micafungin heteroresistance in C. parapsilosis. To facilitate rapid detection of micafungin heteroresistance in C. parapsilosis, we constructed a predictive machine learning framework that classifies isolates as heteroresistant or susceptible using a maximum of ten genomic features. These results connect heteroresistance to unexplained antifungal prophylaxis failure in allo-HCT recipients and demonstrate a proof-of-principle diagnostic approach with the potential to guide clinical decisions and improve patient care.

1220. Comparing Breakthrough Fungal Infections in Acute Myeloid Leukemia (AML) and Myelodysplastic Syndrome (MDS) Patients Receiving Prophylaxis with Different Azoles

Abstract Background Posaconazole is recommended for primary prophylaxis in neutropenic patients with acute myeloid leukemia (AML) or myelodysplastic syndrome (MDS) receiving induction chemotherapy. Despite prophylaxis, breakthrough invasive fungal infections (bIFIs) still arise. Initiating posaconazole is not always feasible, and may necessitate use of alternative azoles. The primary objective of this study was to evaluate the rate of bIFIs in patients receiving prophylaxis with posaconazole versus alternative azoles. The secondary objective reviewed reasons for alternative azole use. Methods A retrospective chart review was conducted at University of Washington Medical Center (UWMC) and Fred Hutchinson Cancer Center (FHCC). Patients who received induction chemotherapy for AML/MDS from March 2021 to November 2022 and received a prophylactic azole for at least 7 days during neutropenia were included. Outcomes were evaluated with Chi-Square. The incidence of bIFI was evaluated up to 12 weeks from induction chemotherapy, or until consolidation chemotherapy or hematopoietic stem cell transplant, whichever came first. Results The initial query yielded 175 patients with AML/MDS. Of these, 88 patients were included: 74 received posaconazole and 14 received an alternate azole (Table 1). BIFIs occurred in 9 patients (posaconazole (n=7, 9.5%), alternative azole (n=2, voriconazole, 14.2%); p=0.631) (Figure 1). The most common reason for initiating an alternative azole was insurance restrictions/high cost (Figure 2). Conclusion Numerically, we found reduced incidence of bIFIs among patients receiving posaconazole compared to alternative azoles. Insurance restrictions/cost was the most common reason for alternative azole utilization. This barrier may increase risk of bIFIs, and additional efforts should be considered to use posaconazole over alternative azoles. Disclosures Catherine Liu, MD, Pfizer: Site Investigator|SNIPR BIOME: Advisor/Consultant

Incidence of breakthrough fungal infections on isavuconazole prophylaxis compared to posaconazole and voriconazole.

Invasive fungal infections (IFIs) are a common infectious complication during the treatment of acute myeloid leukemia (AML), high-risk myelodysplastic syndrome (MDS) or post hematopoietic cell transplantation (HCT). For these patients, the National Comprehensive Cancer Network recommends posaconazole or voriconazole for IFI prophylaxis. In clinical practice, however, there has been increased use of isavuconazole due to favorable pharmacokinetic and pharmacodynamic parameters despite limited data for this indication. The comparative prophylactic efficacy of antifungals in this patient population has not been reported, and an analysis is warranted. This retrospective, matched cohort, single-center study, included AML, MDS, or HCT patients who began treatment or underwent transplant between January 1, 2015 and July 31, 2021. Isavuconazole patients were matched 1:2 with patients receiving posaconazole or voriconazole prophylaxis. A total of 126 patients were included, 42 received isavuconazole, 81 received posaconazole, and three received voriconazole. The majority of patients were male receiving secondary IFI prophylaxis while receiving steroids for treatment of GVHD. The incidence of possible, probable or proven IFI was 16.7% in the isavuconazole group compared to 10.7% in the posaconazole and voriconazole group (OR 1.28, 95% CI -0.9-1.4; p = .67). Hepatotoxicity occurred in 16 total patients, 14 receiving posaconazole and two receiving isavuconazole. Patients who received isavuconazole prophylaxis during AML induction therapy or post-HCT experienced a similar incidence of breakthrough fungal infections compared to those who received posaconazole or voriconazole. These results suggest no difference in antifungal prophylactic efficacy; however larger prospective comparative studies are needed.

Efficacy and Safety of Caspofungin Treatment in Febrile Neutropenic Patients with Hematological Disorders: A Multicenter Consecutive Case Series.

Introduction Invasive fungal infections have been attracting attention as significant fatal complications in patients with febrile neutropenia (FN) who undergo intensive chemotherapy or hematopoietic stem cell transplantation to treat hematological malignancies. Although clinical trials are already underway in other countries, evidence supporting the use of caspofungin (CAS) in FN patients in Japan is still insufficient. Methods A retrospective study of patients treated with CAS for FN associated with hematological diseases between April 2015 and March 2018 was conducted to determine the treatment efficacy and safety. The study was conducted as a multicenter collaboration, and the data of 52 patients who met all of the inclusion criteria were analyzed. A five-composite-endpoint method was used, and the treatment was judged to be effective when all five endpoints (defervescence during neutropenia; no breakthrough fungal infections; resolution of baseline fungal infections; a survival for seven days or more after the completion of therapy; and no discontinuation of therapy due to side effects or invalidity) were met. Results The efficacy rate was 53.8% (28/52), which is close to the average reported efficacy rate. Adverse events included liver dysfunction and electrolyte abnormalities, but no renal dysfunction or serious events were seen. Conclusion These results suggest that the use of CAS in FN patients with hematological diseases is effective and well-tolerated, and we believe that the use of CAS could become a significant treatment in Japan.

Antifungal Prophylaxis With Posaconazole in Immunocompromised Children Younger Than 13 Years.

Prophylaxis with posaconazole (PP) is effective in the prevention of invasive fungal infections in immunocompromised adult patients. However, evaluation of its effectiveness and safety in children is limited. The aim of the study was to describe the use of posaconazole as antifungal prophylaxis in children. We reviewed the medical records of immunocompromised patients younger than 13 years with hematologic diseases and post hematopoietic stem cell transplant (HSCT) who received antifungal PP at the Instituto Nacional de Salud del Niño San Borja (INSN-SB) in Lima, Peru, from January 2014 to December 2018. Fifty-six courses of PP were identified in 47 patients with a median age of 7.5 years (IQR, 4-10), 51.6% (n = 24) of whom were female. The main underlying medical conditions were aplastic anemia (n = 19, 33.9%), acute lymphoblastic leukemia (n = 18, 32.1%), acute myeloid leukemia (n = 14, 25.0%), and 34.1% had undergone HSCT. The median dose of posaconazole was 13.62 mg/kg/day (IQR, 12.0-16.8), and the median duration of PP was 24 days (IQR, 16-82). Gastrointestinal symptoms included abdominal pain (17.9%), nausea (16.1%), diarrhea (7.1%), and vomiting (3.6%). Elevated alanine aminotransferase and aspartate aminotransferase levels were observed in 9/35 patients (25.7%) and 10/51 (19.6%) patients, respectively. Five cases of breakthrough fungal infection were identified (8.9%). Patients younger than 13 years who received PP showed an increase in transaminase values, and the development of breakthrough fungal infections.

Incidence of Breakthrough Fungal Infections in Acute Myeloid Leukemia Patients Receiving Low Intensity Therapy in the Upfront and Relapsed/Refractory Setting

Introduction: New treatment strategies with low intensity therapy have emerged for acute myeloid leukemia (AML) patients who are not candidates for intensive therapy. To date, there is limited data on the frequency of invasive fungal infections (IFIs) in patients treated with low intensity regimens, and there is no consensus on the most appropriate prophylactic antifungal agent to use in either the newly diagnosed or relapsed/refractory setting. At our institution, fluconazole is the prophylactic antifungal agent of choice for neutropenic patients receiving low intensity therapy, however the appropriateness of fluconazole is being questioned due to the depth and duration of neutropenia observed in these patients. Rates of breakthrough IFIs need to be better characterized to optimize antifungal prophylaxis in this patient population.Methods: This is a retrospective review of AML patients treated with low intensity therapy from January 2017 through May 2020 for both newly diagnosed and relapsed/refractory disease. Patients were included if they received fluconazole as prophylaxis during periods of neutropenia and received at least two cycles of low intensity treatment. Low intensity regimens included hypomethylating agent (HMA) monotherapy or a combination of venetoclax with either a HMA or low dose cytarabine (LDAC). Any patient with a contraindication to fluconazole or those who received prophylaxis with an alternative antifungal agent (i.e. posaconazole, voriconazole, isavuconazole, and micafungin), history of previous IFI, or history of a stem cell transplant were excluded. The primary objective was to determine the incidence of breakthrough IFIs. The secondary objective was to further characterize IFI occurrences as possible, probable or proven using criteria defined by the European Organization for Research and Treatment of Cancer and the Mycoses Study Group Education and Research Consortium (EORTC/MSGERC). An occurrence of IFI was defined as receipt of any systemic antifungal agent, aside from fluconazole, for four or more days for suspected IFI. Patients were evaluated for antifungal escalation from the time of low intensity treatment initiation through 30 days after treatment discontinuation.Results: Eighty encounters were included for analysis. The median age of the cohort was 73 years (interquartile range [IQR] 67 - 80) and 70% of patients were newly diagnosed (n = 56). HMA/venetoclax was the most commonly utilized regimen (66%, n = 53) followed by HMA monotherapy (29%, n = 23) and LDAC/venetoclax (5%, n = 4). The median number of treatment cycles was 5 (IQR 3 - 9). Nineteen IFI occurrences (24%) were documented, with ten in the newly diagnosed population (18%, n = 10/56) and nine in relapsed/refractory patients (38%, n = 9/24). There were no proven, four probable and fourteen possible IFIs. Of the four probable infections, three were in relapsed/refractory patients. Median times to IFI onset from low intensity treatment initiation were 82 and 80 days for the newly diagnosed and relapsed/refractory populations, respectively. Of the patients with an IFI, 15/19 (79%) were neutropenic at IFI onset.Conclusions: IFIs are a serious complication of AML as these infections are associated with significant morbidity and mortality. With 24% of patients requiring antifungal escalation, our study demonstrates that breakthrough IFIs remain a concern for patients receiving low intensity therapy and fluconazole prophylaxis. Incidence of IFI was higher in the relapsed/refractory setting, which is an expected finding as these patients are typically subjected to multiple lines of therapy, leading to poor hematopoietic reserves and more prolonged periods of profound neutropenia. Additional analysis is needed for determination of risk factors, beyond relapsed/refractory disease, to potentially identify subsets of patients at highest risk of developing IFIs as these patients may benefit from closer monitoring and longer durations of prophylaxis. Given these findings, it is reasonable to consider prophylaxis with an extended spectrum antifungal agent against molds for patients receiving low intensity therapy. [Display omitted] DisclosuresEllis: Rafael Pharmaceuticals: Consultancy. Pardee: Karyopharm Pharmaceuticals: Research Funding; AbbVie: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Rafael Pharmaceuticals: Consultancy, Research Funding; Genetech: Membership on an entity's Board of Directors or advisory committees; BMS: Speakers Bureau; Pharmacyclics: Speakers Bureau.

The Prediction and Prognosis of Fungal Infection in Lung Transplant Recipients-A Retrospective Cohort Study in South Korea.

(1) Background: Lung transplant recipients (LTRs) are at substantial risk of invasive fungal disease (IFD), although no consensus has been reached on the use of antifungal agents (AFAs) after lung transplantation (LTx). This study aimed to assess the risk factors and prognosis of fungal infection after LTx in a single tertiary center in South Korea. (2) Methods: The study population included all patients who underwent LTx between January 2012 and July 2019 at a tertiary hospital. It was a retrospective cohort study. Culture, bronchoscopy, and laboratory findings were reviewed during episodes of infection. (3) Results: Fungus-positive respiratory samples were predominant in the first 90 days and the overall cumulative incidence of Candida spp. was approximately three times higher than that of Aspergillus spp. In the setting of itraconazole administration for 6 months post-LTx, C. glabrata accounted for 36.5% of all Candida-positive respiratory samples. Underlying connective tissue disease-associated interstitial lung disease, use of AFAs before LTx, a longer length of hospital stay after LTx, and old age were associated with developing a fungal infection after LTx. IFD and fungal infection treatment failure significantly increased overall mortality. Host factors, antifungal drug resistance, and misdiagnosis of non-Aspergillus molds could attribute to the breakthrough fungal infections. (4) Conclusions: Careful bronchoscopy, prompt fungus culture, and appropriate use of antifungal therapies are recommended during the first year after LTx.

Pharmacotherapy Modifications Due to Drug Interactions with Concomitant Fungal Prophylaxis and Nontuberculous Mycobacteria Treatment after Transplant

Introduction Patients undergoing orthotopic heart transplant (OHT) have a 0.2 to 2.8% rate of infection with nontuberculous mycobacteria (NTM) in the year after transplant. Rifamycins, particularly rifampin, remain the backbone of NTM therapy; rifampin therapy can be especially challenging in solid organ transplant (SOT) due to potent CYP3A4 induction. Rifabutin, an alternative rifamycin, though less studied, is commonly substituted for rifampin in SOT due to less drug-drug interactions (DDI). Rifabutin is also a CYP3A4 substrate which can be impacted by concomitant CYP3A4 inhibitors. We report a case of an OHT recipient requiring systemic fungal prophylaxis while on rifabutin for pulmonary NTM. Case Report He is a 44-year old Caucasian male on 12 months of NTM treatment with rifabutin, azithromycin, and ethambutol who presented for OHT in his final month of treatment for pulmonary Mycobacterium kansasii. After OHT, he was started on high-dose steroids and triple-drug immunosuppression (IS). His NTM regimen was extended for another month. In addition to his IS regimen, isavuconazole was initiated for fungal prophylaxis rather than standard protocol posaconazole, for less CYP3A4 inhibition of rifabutin. Due to DDI, he required close therapeutic drug monitoring (TDM) to attain tacrolimus levels of 10-12ng/mL, requiring 10-15 mg/day (0.11-0.16 mg/kg/day) on the CYP3A4 inhibitor/inducer regimen. Rifabutin also remained therapeutic (0.3mcg/ml) on 300mg daily despite isavuconazole inhibition. After completion of rifabutin, tacrolimus requirements reduced to 6mg/day (0.06 mg/kg/day) with isavuconazole CYP3A4 inhibition alone. No breakthrough fungal infections occurred during isavuconazole prophylaxis despite the potential for rifabutin CYP3A4 induction. Summary Use of moderate CYP3A4 inhibitor isavuconazole with rifabutin did not result in rifabutin toxicity, particularly the shared ocular effects of ethambutol, and permitted effective systemic fungal prophylaxis. The degree of reduced exposure of isavuconazole inhibition due to a concomitant CYP3A4 induction of rifabutin remains unknown and requires monitoring for breakthrough infections. Close TDM may permit concomitant administration of significantly interacting CYP3A4 inhibitors, inducers, and substrates in complicated SOT patients.

1260. Activity of Manogepix (APX001A) against 2,669 Fungal Isolates from the SENTRY Surveillance Program (2018-2019) Stratified by Infection Type

BackgroundExisting antifungal agents are active against many common fungal pathogens; however, breakthrough fungal infections occur and often involve less frequently encountered yeast and mould isolates. These rarer isolates tend to exhibit diminished susceptibility to current agents. Manogepix (MGX, APX001A) is a novel inhibitor of the fungal Gwt1 enzyme. The prodrug (fosmanogepix), is being evaluated in Phase 2 clinical trials for invasive candidiasis/candidemia, Candida auris infections, and invasive aspergillosis. In this study, we evaluated the in vitro activity of MGX and comparators against 2,669 clinical fungal isolates collected worldwide (2018-2019) and stratified by infection type.MethodsFungal isolates were collected from medical centers located in North America (34 sites; 42.3%), Europe (30 sites; 37.9%), Asia-Pacific (11 sites; 12.3%), and Latin America (7 sites; 7.6%). Isolates were collected from bloodstream infections (BSI; 51.7%), pneumonia in hospitalized patients (PIHP; 21.1%), skin and skin structure infections (SSSI; 5.5%), urinary tract infections (UTI; 2.3%), intraabdominal infections (IAI; 1.9%), and other infection types (17.5%).ResultsMGX demonstrated potent in vitro activity against 1,887 Candida spp. isolates from BSI, PIHP, SSSI, and all infection types (MIC50/90, 0.008/0.03-0.06 mg/L) outperforming all comparator agents (Table). Similarly, MGX was equally active against 578 Aspergillus spp. isolates (MEC50/90, 0.015/0.03 mg/L), regardless of infection type. MGX was active against Cryptococcus neoformans var. grubii isolates from BSI and ALL infection types with MIC50/90 values of 0.5/2 mg/L. Scedosporium spp. isolates from PIHP and all infection types were inhibited by low concentrations of MGX (MEC50/90, 0.03/0.03 mg/L).Table 1 ConclusionMGX demonstrated potent antifungal activity against Candida spp., Aspergillus spp., C. neoformans var. grubii, and non-Aspergillus moulds, including Scedosporium spp. isolates. Notable activity was seen against C. auris, echinocandin-resistant Candida spp., azole-resistant Aspergillus, and Scedosporium spp. isolates. Further clinical development of fosmanogepix in difficult-to-treat resistant fungal infections is warranted.DisclosuresMichael A. Pfaller, MD, Amplyx Pharmaceuticals (Research Grant or Support)Basilea Pharmaceutica International, Ltd (Research Grant or Support)Cidara Therapeutics (Research Grant or Support)Cidara Therapeutics (Research Grant or Support)Department of Health and Human Services (Research Grant or Support)Fox Chase Chemical Diversity Center (Research Grant or Support)Paratek Pharma, LLC (Research Grant or Support) Robert K. Flamm, PhD, A. Menarini Industrie Farmaceutiche Riunite S.R.L. (Research Grant or Support)Amplyx Pharmaceuticals (Research Grant or Support)Basilea Pharmaceutica International, Ltd (Research Grant or Support)Department of Health and Human Services (Research Grant or Support)Melinta Therapeutics, Inc. (Research Grant or Support) Shawn A. Messer, PhD, Amplyx Pharmaceuticals (Research Grant or Support)Fox Chase Chemical Diversity Center (Research Grant or Support) Beth A. Schaefer, n/a, Amplyx Pharmaceuticals (Research Grant or Support) Paul Bien, MS, Amplyx Pharmaceuticals (Employee) Mariana Castanheira, PhD, 1928 Diagnostics (Research Grant or Support)A. Menarini Industrie Farmaceutiche Riunite S.R.L. (Research Grant or Support)Allergan (Research Grant or Support)Allergan (Research Grant or Support)Amplyx Pharmaceuticals (Research Grant or Support)Cidara Therapeutics (Research Grant or Support)Cidara Therapeutics (Research Grant or Support)Cipla Ltd. (Research Grant or Support)Cipla Ltd. (Research Grant or Support)Fox Chase Chemical Diversity Center (Research Grant or Support)GlaxoSmithKline (Research Grant or Support)Melinta Therapeutics, Inc. (Research Grant or Support)Melinta Therapeutics, Inc. (Research Grant or Support)Melinta Therapeutics, Inc. (Research Grant or Support)Merck (Research Grant or Support)Merck (Research Grant or Support)Merck & Co, Inc. (Research Grant or Support)Merck & Co, Inc. (Research Grant or Support)Paratek Pharma, LLC (Research Grant or Support)Pfizer (Research Grant or Support)Qpex Biopharma (Research Grant or Support)

Outcomes of Antifungal Prophylaxis in High-Risk Haematological Patients (AML under Intensive Chemotherapy): The SAPHIR Prospective Multicentre Study.

Antifungal prophylaxis (AFP) is recommended by international guidelines for patients with acute myeloid leukaemia (AML) undergoing induction chemotherapy and allogeneic hematopoietic cell transplantation. Nonetheless, treatment of breakthrough fungal infections remains challenging. This observational, prospective, multicentre, non-comparative study of patients undergoing myelosuppressive and intensive chemotherapy for AML who are at high-risk of invasive fungal diseases (IFDs), describes AFP management and outcomes for 404 patients (65.6% newly diagnosed and 73.3% chemotherapy naïve). Ongoing chemotherapy started 1.0 ± 4.5 days before inclusion and represented induction therapy for 79% of participants. In 92.3% of patients, posaconazole was initially prescribed, and 8.2% of all patients underwent at least one treatment change after 17 ± 24 days, mainly due to medical conditions influencing AFP absorption (65%). The mean AFP period was 24 ± 32 days, 66.8% stopped their prophylaxis after the high-risk period and 31.2% switched to a non-prophylactic treatment (2/3 empirical, 1/3 pre-emptive/curative). Overall, 9/404 patients (2.2%) were diagnosed with probable or proven IFDs. During the follow-up, 94.3% showed no signs of infection. Altogether, 20 patients (5%) died, and three deaths (0.7%) were IFD-related. In conclusion, AFP was frequently prescribed and well tolerated by these AML patients, breakthrough infections incidence and IFD mortality were low and very few treatment changes were required.

Diagnosis of Breakthrough Fungal Infections in the Clinical Mycology Laboratory: An ECMM Consensus Statement.

Breakthrough invasive fungal infections (bIFI) cause significant morbidity and mortality. Their diagnosis can be challenging due to reduced sensitivity to conventional culture techniques, serologic tests, and PCR-based assays in patients undergoing antifungal therapy, and their diagnosis can be delayed contributing to poor patient outcomes. In this review, we provide consensus recommendations on behalf of the European Confederation for Medical Mycology (ECMM) for the diagnosis of bIFI caused by invasive yeasts, molds, and endemic mycoses, to guide diagnostic efforts in patients receiving antifungals and support the design of future clinical trials in the field of clinical mycology. The cornerstone of lab-based diagnosis of breakthrough infections for yeast and endemic mycoses remain conventional culture, to accurately identify the causative pathogen and allow for antifungal susceptibility testing. The impact of non-culture-based methods are not well-studied for the definite diagnosis of breakthrough invasive yeast infections. Non-culture-based methods have an important role for the diagnosis of breakthrough invasive mold infections, in particular invasive aspergillosis, and a combination of testing involving conventional culture, antigen-based assays, and PCR-based assays should be considered. Multiple diagnostic modalities, including histopathology, culture, antibody, and/or antigen tests and occasionally PCR-based assays may be required to diagnose breakthrough endemic mycoses. A need exists for diagnostic tests that are effective, simple, cheap, and rapid to enable the diagnosis of bIFI in patients taking antifungals.

Efficacy and Tolerability of Isavuconazole versus Posaconazole for Fungal Prophylaxis after Lung Transplantation

Azole antifungals are commonly prescribed for fungal prophylaxis (ppx) following lung transplant, but have many side effects and drug interactions. Isavuconazole, a new broad-spectrum azole antifungal, may obviate these issues. We retrospectively reviewed all lung transplant recipients (LTR) from February 2018 through September 2019 who received either ISA or POS for fungal ppx for 3 months post-transplant. Prior to February 2019 all patients received POS for ppx. Starting February 2019, POS was replaced by ISA at standard dosing. All patients received basiliximab induction and standard triple immunosuppression post-transplant. Surveillance bronchoscopies were performed at 1, 3, 6, and 12 months post-transplant. In total, we reviewed 24 LTR who received ISA and 29 who received POS. Baseline characteristics were similar between groups. Median duration of follow-up was significantly shorter for the ISA group (137 vs. 340 days, p<0.01). Breakthrough fungal infections occurred in 3 (13%) and 2 (7%) patients in the ISA and POS groups, respectively (p=0.65). All ISA patients developed oropharyngeal candidiasis; in the POS group there was one each of candida empyema and mold colonization. Post-ppx fungal infections occurred in 1 (4%) and 5 (17%) patients in the ISA and POS groups, respectively (p=0.20). All of these were mold colonization except for one case of oropharyngeal candidiasis. There was no difference between fungal-infection free survival based on Kaplan-Meier analysis (p=0.69). POS was held in two cases and discontinued in 1 patient due to a drug interaction causing hepatotoxicity compared to zero patients receiving ISA (p=0.24). Breakthrough fungal infections were similar between LTR receiving ISA or POS for fungal ppx. Longer follow-up of ISA patients is needed for definitive comparison of long-term infection risk. POS was discontinued in more patients due to drug interactions. ISA is a reasonable choice for primary fungal ppx in LTR.

Incidence of Invasive Fungal Infections in Acute Leukemia Patients Utilizing Micafungin Prophylaxis Compared to Second-Generation Azole Prophylaxis

Introduction/Background: Standard therapy for both acute myeloid leukemia (AML) and acute lymphoblastic leukemia (ALL) is myelosuppressive, and patients are expected to be neutropenic for a prolonged period. Due to the high risk of infection, antimicrobial prophylaxis is warranted and should be continued throughout neutropenia. The incidence of documented invasive fungal infections ranges from 12 to 24% in patients with AML and approximately 6.5% in patients with ALL. Guidelines currently include posaconazole as a category 1 recommendation for antifungal prophylaxis, with echinocandins and other azole antifungals as category 2B. However, posaconazole can be subject to drug-drug interactions and can increase the risk of hepatotoxicity, both of which can be problematic in acute leukemia patients undergoing chemotherapy. For patients unable to receive posaconazole or another second-generation azole antifungal, micafungin is utilized. To our knowledge, there are no studies comparing second-generation azole antifungals to micafungin as prophylaxis in both AML and ALL during initial or relapsed/refractory induction therapy. The aim of this retrospective study is to compare the incidence of invasive fungal infections in patients with acute leukemia in the setting of micafungin or second-generation azole antifungal prophylaxis during initial and/or relapsed/refractory induction therapy at an academic medical center. Methods: Retrospective, single-center study from June 22, 2013 to June 22, 2018. Detailed chart reviews were performed by hand. Results: The incidence of invasive fungal infections within 100 days of chemotherapy was 11.2% in patients who received a second-generation azole and 2.7% in patients who received micafungin (P=0.7618). The incidence of invasive fungal infections within 100 days in patients who received a high intensity AML regimen was 11.2%, low intensity AML regimen 0.9%, and ALL regimen 1.8% (P=0.5378). The incidence of invasive fungal infections within 30 days of chemotherapy was 4.5% in patients who received a second-generation azole and 2.2% in patients who received micafungin (P=0.2447). The most common reason for micafungin prophylaxis was drug-drug interactions with standard ALL regimens that utilize vincristine. Of those with a documented fungal infection, 14 patients (6.3%) had a proven invasive fungal infection, and 17 patients (7.6%) had a probable/possible invasive fungal infection. The most common site of infection was in the chest (9.8%), followed by fungemia (2.2%). Other sites of infection include the brain, sinuses, liver/spleen, and skin. Beta-D-glucan was collected in 17 patients, and galactomannan antigen was collected in 26 patients. Three patients had a positive beta-D-glucan, and 1 patient had an indeterminate beta-D-glucan. Two patients had a positive galactomannan antigen. Fusarium species accounted for 4 positive cultures in patients. For those patients who did experience an invasive fungal infection, 23 out of the 31 patients (74.2%) were on posaconazole, 6 patients on micafungin (19.4%), and 2 on voriconazole (6.5%). Ten out of the 14 proven fungal infections (71.4%) occurred while on posaconazole prophylaxis, and 3 of these patients had posaconazole levels &lt;0.7 mcg/mL. Twenty-one patients (67.7%) with documented infections had a neutrophil nadir &lt; 0.1x109/L. The majority (93.5%) of those with breakthrough infections while on antifungal prophylaxis were switched to another antifungal. Conclusions: Micafungin is a reasonable alternative therapy for use in patients who are unable to receive second-generation azoles as antifungal prophylaxis during induction therapy for acute leukemia. Some invasive fungal infections occurred while patients had sub-therapeutic posaconazole levels, however others had breakthrough fungal infections with therapeutic levels. Our conclusions are limited by the small sample size and non-randomized, retrospective nature of this analysis. Disclosures Erba: Agios, Amgen, Astellas Pharma, Daiichi Sankyo, ImmunoGen, Janssen, Jazz Pharmaceuticals, Juno, Millennium, Seattle Genetics: Research Funding; Celgene, Incyte, Novartis: Speakers Bureau; Amgen, Celgene, Daiichi Sankyo, ImmunoGen, Incyte, Jazz Pharmaceuticals, Millennium, Novartis, Ono, Pfizer, Seattle Genetics, Sunesis: Consultancy. LeBlanc:Seattle Genetics: Consultancy, Research Funding; Astra Zeneca: Consultancy, Research Funding; AbbVie: Membership on an entity's Board of Directors or advisory committees; Agios: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; NINR/NIH: Research Funding; Jazz Pharmaceuticals: Research Funding; Amgen: Membership on an entity's Board of Directors or advisory committees; CareVive: Consultancy; American Cancer Society: Research Funding; Daiichi-Sankyo: Membership on an entity's Board of Directors or advisory committees; Helsinn: Consultancy; Medtronic: Membership on an entity's Board of Directors or advisory committees; Otsuka: Consultancy, Membership on an entity's Board of Directors or advisory committees; Pfizer Inc: Consultancy; Heron: Membership on an entity's Board of Directors or advisory committees; Duke University: Research Funding; Celgene: Honoraria; Flatiron: Consultancy. Rizzieri:AROG, Bayer, Celgene, Celltron, Mustang, Pfizer, Seattle Genetics, Stemline: Consultancy; Stemline: Research Funding; Celgene, Gilead, Seattle Genetics, Stemline: Other: Speaker; AbbVie, Agios, AROG, Bayer, Celgene, Gilead, Jazz, Novartis, Pfizer, Sanofi, Seattle Genetics, Stemline, Teva: Other: Advisory Board.

2112. Voriconazole for Primary Prophylaxis: A Decade of Trends and Outcomes

BackgroundInvasive fungal infections (IFI) continue to affect the immunocompromised patient population. Many of these patients require antifungal prophylaxis. Voriconazole is an azole antifungal that has been utilized for preventing IFIs but does not have an approved indication for prophylaxis.MethodsAdult patients admitted to Duke University Hospital from January 1, 2005 to December 31, 2015 who had received at least 2 days of systemic voriconazole as primary prophylaxis were included in this retrospective medical records review. Demographics, underlying comorbidities, adverse events, drug interactions, voriconazole blood concentrations, and microbiological data were assessed.ResultsOur review identified 403 patients receiving voriconazole for primary prophylaxis. 220 (55.6%) were male, 303 (75.2%) were Caucasian, and the mean age was 46.0 ± 15.7 years. 233 (57.8%) had leukemia, and 63 (15.6%) had lymphoma. 301 (74.7%) underwent hematopoietic transplant (BMT), and 45 (11.2%) had a solid-organ transplant. 176 (43.7%) patients received chemotherapy and 261 (64.8%) received immunosuppressive drugs. The mean voriconazole total daily maintenance dose was 416.1 ± 65.9 mg (5.5 ± 1.6 mg/kg/day). Patients received inpatient voriconazole for a mean of 19.5 ± 16.5 days. 371 (92.1%) patients received a concomitant interacting drug. Only 140 (43.7%) patients had therapeutic drug monitoring. The mean first voriconazole serum concentration was 1.8 ± 1.7 mg/L. 87 (21.6%) patients discontinued voriconazole prematurely; 41 (10.2% overall) of these patients had an adverse event requiring discontinuation. 5 had breakthrough fungal infections with microbiological data identifying a fungal species, which included Rhizopus spp. among others.ConclusionVoriconazole is frequently used for primary prophylaxis of IFIs and most commonly in BMT. It appears to be relatively well tolerated with some adverse side-effects (~10%) despite many potential drug–drug interactions and provides appropriate fungal coverage for many immunosuppressed patients. However, few patients had breakthrough fungal infections while receiving voriconazole. In a real-world setting, voriconazole can provide antifungal prevention in certain high-risk patients.Disclosures All authors: No reported disclosures.

Breakthrough Fungal Infections in Patients With Leukemia Receiving Isavuconazole.

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.

Risk factors for subtherapeutic levels of posaconazole tablet.

Posaconazole is the prophylactic antifungal of choice for patients with haematological malignancies at high risk of invasive fungal infections (IFIs). Studies have demonstrated that subtherapeutic concentrations of posaconazole are associated with breakthrough fungal infections and specific risk factors for subtherapeutic troughs associated with the suspension formulation have been identified. However, these risk factors have not been evaluated in a large patient population with the recently approved tablet formulation. To determine the risk factors for subtherapeutic posaconazole troughs associated with the tablet formulation in patients receiving posaconazole as IFI prophylaxis. From 1 February 2013 to 31 March 2015 all posaconazole serum trough concentrations were evaluated. A total of 157 patients receiving posaconazole tablet for prophylaxis during induction therapy for haematological malignancies and allogeneic stem cell transplant recipients with graft-versus-host disease were included for analysis. Overall, 28 patients (18%) had subtherapeutic troughs (<700 ng/mL). Patients were more likely to have subtherapeutic troughs if they had diarrhoea (n = 24; 83%) (P < 0.001), were receiving a proton pump inhibitor (n = 27; 93%) (P = 0.016) and weighed >90 kg (n = 14; 48%) (P = 0.047). While the posaconazole tablet has provided more consistent therapeutic concentrations when compared with the suspension there may still be a role for therapeutic drug monitoring (TDM). These results may guide us to a specific population in which TDM is necessary to identify subtherapeutic troughs.

Therapeutic Drug Monitoring of Posaconazole in Adult Acute Myeloid Leukemia (Aml) Patients Receiving Posaconazole Prophylaxis during Induction: Experience from a Center with High Invasive Fungal Infection (IFI)Burden

▪Background: Posaconazole has been recommended as an antifungal of choice for IFI prophylaxis in AML during induction therapy. Very high incidence of possible and probable IFI (70%) during induction at our centre led to adoption of posaconazole prophylaxis. However, approximately 50% of patients still require change of antifungal due to suspected breakthrough IFI raising the possibility of inadequate plasma levels due to various factors (variable absorption, metabolism and drug interactions). To address this concern, we evaluated the role of therapeutic drug monitoring (TDM) in AML patients receiving posaconazole prophylaxis to identify whether suboptimal plasma levels (<700 ng/mL) are associated with breakthrough IFI.Method: This prospective observational study included all patients, 18 years or more, undergoing induction chemotherapy for de novo AML with no evidence of IFI (normal CT chest, and galactomannan assay) and on posaconazole prophylaxis between May2015 to February 2016 at our centre. Posaconazole oral suspension 200 mg three times daily was given for antifungal prophylaxis from day 1 of induction until neutrophil recovery to more than 500 cells/μL, occurrence of a confirmed or suspected IFI or development of drug related toxicity or intolerance. The details regarding demography, weight, BMI at diagnosis were recorded. During therapy all adverse events including vomiting and diarrhea were recorded as per CTCAE version 4.03. Concomitant drug history and use of proton pump inhibitors, antacids, metoclopramide and domperidone during treatment period were noted. Blood samples (7 am) for detecting posaconazole trough levels were collected daily from day 4 till day 12 of induction. If patient developed symptoms and signs suggestive of IFI during induction after day 12, then blood sample was drawn for posaconazole trough levels. Plasma posaconazole levels were estimated at by HPLC method. The diagnosis of IFI was in accordance with the revised European Organization for Research and Treatment of Cancer /Mycoses Study Group definitions published in 2008. Breakthrough invasive fungal infection was also diagnosed if there was failure to respond to intravenous antibiotics along with negative cultures and fever defervescence with change in antifungal therapy. The primary objective of the study was to assess the percentage of patients achieving target posaconazole plasma levels. The secondary objectives included i) impact of achieving target drug concentration in preventing breakthrough fungal infections. ii) identification of factors associated with subtoptimal posaconazole levels. iii) Time to achieve steady state concentration or target trough concentrations of posaconazole.Results: A total of 366 samples were collected from 45 patients with median number of 8 samples (range 1-9) per patient. Median age of patients was 36 years (range 18-45 years). Thirty two were males. Thirty-nine patients received 3+7 regimen and 6 were treated with cladribine along with daunomycin and cytarabine. Eleven patients (24%) did not achieve target plasma levels (≥700 ng/mL) even once till day 12. Median time to achieve steady state concentration was 5 days (range 4-10). At steady state 20 (44% ) patients had suboptimal plasma levels. On serial monitoring, a declining trend in plasma levels was observed after day 8 in 31 patients. Twenty three patients (51%) developed possible/ probable IFI on posaconazole prophylaxis. The median time to develop IFI was 13 days (range 4-24 days). Twenty out of 23 patients (87%) who developed IFI had suboptimal plasma levels as compared to 13 out of 22 patients (60%) who did not develop IFI (p-0.04). In all but 3 patients, the plasma levels declined before breakthrough IFI. On logistic regression analysis, both the steady state concentration and plasma posaconazole levels before breakthrough were strong predictors of occurrence of breakthrough IFI. Presence of mucositis, vomiting, diarrhea, use of antacid was associated with low plasma levels on univariate analysis. On multivariate analysis presence of mucositis and antacids remained significantly associated with low plasma levels.Conclusion: TDM has a role in patients receiving posaconazole prophylaxis, however it still needs to be seen if dose adjustments based on plasma levels can reduce the risk of breakthrough IFI. DisclosuresNo relevant conflicts of interest to declare.

Rare severe mycotic infections in children receiving empirical caspofungin treatment for febrile neutropenia

Empirical antifungal therapy is most often given to patients with leukemia. However breakthrough fungal infections under antifungal therapy are not uncommon. Four children, with hematologic malignant disease developed mycotic breakthrough infections while on empirical caspofungin treatment for a median of 14 (range 11–19) days. Trichosporon asahii was detected in the blood culture of two patients and Geotrichum capitatum in the other two (one patient also had positive cerebrospinal fluid culture). Because the patients’ clinical situation worsened, voriconazole was empirically added for two patients three and five days before the agent was detected. The first sterile blood culture was obtained 3–7 days of voriconazole treatment. All patients reached clear cultures but one patient died. One patient with central nervous system infection with G. capitatum had severe neurological sequelae. Very severe fungal infections can occur during empirical caspofungin therapy. Therefore, patients should be followed closely.

Superior Serum Concentrations with Posaconazole Delayed-Release Tablets Compared to Suspension Formulation in Hematological Malignancies.

Posaconazole (PCZ), approved for prophylaxis against invasive fungal disease in high-risk patients, is commercially available orally as a suspension formulation (PCZ-susp) and as a delayed-release tablet (PCZ-tab). We evaluated the serum steady-state concentrations (Css) of PCZ stratified by the administered formulation for antifungal prophylaxis in patients with myeloid malignancies (n = 150). The primary outcome was the attainment rate of the target Css of ≥700 ng/ml. Secondary outcomes included toxicity assessment (hepatotoxicity and corrected QT [QTc] interval prolongation) and breakthrough fungal infections. Patients who received the PCZ-susp (n = 118) or PCZ-tab (n = 32) and had PCZ Css assessment after at least 7 days of therapy were eligible. The median Css in the PCZ-susp group was 390 ng/ml (range, 51 to 1,870 ng/ml; mean, 436 ng/ml) compared to 1,740 ng/ml (range, 662 to 3,350 ng/ml; mean, 1,781 ng/ml) in the PCZ-tab group (P < 0.0001). The percentages of patients achieving the target goal of ≥700 ng/ml were 17% versus 97%, respectively (P < 0.0001). Hepatotoxicity (grade 2 or higher) occurred in 1 patient in each group. QTc interval measurements were available for 32 patients in the PCZ-susp group and for 12 patients in the PCZ-tab group, and prolonged intervals of grade 2 or higher were noted in 9% (n = 3) and 17% (n = 2), respectively (P = 0.6). Breakthrough fungal infections in the PCZ-susp and PCZ-tab groups were 7% (n = 8) and 3% (n = 1), respectively (P = 0.68). We conclude that the use of PCZ-tab was associated with higher Css and with the probability of achieving therapeutic goals without worsening of adverse effects.

Relationship of fluconazole prophylaxis with fungal microbiology in hospitalized intra-abdominal surgery patients: a descriptive cohort study.

IntroductionHistorically, Candida albicans has represented the most common cause of candidemia. However, the proportion of bloodstream infections due to non-albicans Candida species has increased. Because of the risk for candidemia in intra-abdominal surgical patients, some experts advocate the use of fluconazole prophylaxis. The impact of this practice on the distribution of Candida species isolated in breakthrough fungal infections in this population is unknown. We examined the association of fluconazole prophylaxis with the distribution of Candida species in intra-abdominal surgery patients.MethodsWe retrospectively identified cases with a positive blood culture (BCx) for Candida among hospitalized adult intra-abdominal surgery patients between July 2005 and October 2012. Distribution of Candida species isolated represented our primary endpoint. Qualifying surgical cases were determined based on a review of discharge International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM) codes. Patients receiving low-dose fluconazole prior to the positive BCx with a known indication for prophylaxis including neutropenia, ICU exposure or history of organ transplantation were classified as prophylaxis. Appropriateness of fungal treatment was determined by the timing and selection of antifungal agent based on fungal isolate.ResultsAmong 10,839 intra-abdominal surgery patients, 227 had candidemia. The most common Candida species isolated was C. albicans (n = 90, 39.6%) followed by C. glabrata (n = 81, 35.7%) and C. parapsilosis (n = 38, 16.7%). Non-albicans Candida accounted for 57.7% of isolates among the 194 non-prophylaxis patients and 75.8% among the 33 prophylaxis patients (P = 0.001). C. glabrata, the most common non-C. albicans species, was more prevalent than C. albicans in persons given prophylaxis, but not in those without prophylaxis. A total of 63% of those with candidemia were treated inappropriately based on the timing and selection of antifungal administration.ConclusionsSelection pressure from fluconazole prophylaxis in at-risk surgical patients may be associated with a drift toward fluconazole-resistant species in subsequent candidemia. Tools are needed to guide appropriate treatment through the prompt recognition and characterization of candidemia.Electronic supplementary materialThe online version of this article (doi:10.1186/s13054-014-0590-1) contains supplementary material, which is available to authorized users.