An oxindole efflux inhibitor potentiates azoles and impairs virulence in the fungal pathogen Candida auris.

Candida auris is an emerging fungal pathogen that exhibits resistance to multiple drugs, including the most commonly prescribed antifungal, fluconazole. Here, we use a combinatorial screening approach to identify a bis-benzodioxolylindolinone (azoffluxin) that synergizes with fluconazole against C. auris. Azoffluxin enhances fluconazole activity through the inhibition of efflux pump Cdr1, thus increasing intracellular fluconazole levels. This activity is conserved across most C. auris clades, with the exception of clade III. Azoffluxin also inhibits efflux in highly azole-resistant strains of Candida albicans, another human fungal pathogen, increasing their susceptibility to fluconazole. Furthermore, azoffluxin enhances fluconazole activity in mice infected with C. auris, reducing fungal burden. Our findings suggest that pharmacologically targeting Cdr1 in combination with azoles may be an effective strategy to control infection caused by azole-resistant isolates of C. auris.

Fosmanogepix (APX001) Is Effective in the Treatment of Pulmonary Murine Mucormycosis Due to Rhizopus arrhizus.

Mucormycosis is a life-threatening infection with high mortality that occurs predominantly in immunocompromised patients. Manogepix (MGX) is a novel antifungal that targets Gwt1, a protein involved in an early step in the conserved glycosylphosphotidyl inositol (GPI) posttranslational modification pathway of surface proteins in eukaryotic cells. Inhibition of fungal inositol acylation by MGX results in pleiotropic effects, including inhibition of maturation of GPI-anchored proteins necessary for growth and virulence. MGX has been previously shown to have in vitro activity against some strains of Mucorales. Here, we assessed the in vivo activity of the prodrug fosmanogepix, currently in clinical development for the treatment of invasive fungal infections, against two Rhizopus arrhizus strains with high (4.0 µg/ml) and low (0.25 µg/ml) minimum effective concentration (MEC) values. In both invasive pulmonary infection models, treatment of mice with 78 mg/kg or 104 mg/kg fosmanogepix, along with 1-aminobenzotriazole to enhance the serum half-life of MGX in mice, significantly increased median survival time and prolonged overall survival by day 21 postinfection compared to placebo. In addition, administration of fosmanogepix resulted in a 1 to 2 log reduction in both lung and brain fungal burden. For the 104 mg/kg fosmanogepix dose, tissue clearance and survival were comparable to clinically relevant doses of isavuconazole (ISA), which is FDA approved for the treatment of mucormycosis. These results support continued development of fosmanogepix as a first-in-class treatment for invasive mucormycosis.

Fosmanogepix (APX001) Is Effective in the Treatment of Immunocompromised Mice Infected with Invasive Pulmonary Scedosporiosis or Disseminated Fusariosis.

There are limited treatment options for immunosuppressed patients with lethal invasive fungal infections due to Fusarium and Scedosporium Manogepix (MGX; APX001A) is a novel antifungal that targets the conserved Gwt1 enzyme required for localization of glycosylphosphatidylinositol-anchored mannoproteins in fungi. We evaluated the in vitro activity of MGX and the efficacy of the prodrug fosmanogepix (APX001) in immunosuppressed murine models of hematogenously disseminated fusariosis and pulmonary scedosporiosis. The MGX minimum effective concentration (MEC) for Scedosporium isolates was 0.03 µg/ml and ranged from 0.015 to 0.03 µg/ml for Fusarium isolates. In the scedosporiosis model, treatment of mice with 78 mg/kg and 104 mg/kg of body weight fosmanogepix, along with 1-aminobenzotriazole (ABT) to enhance the serum half-life of MGX, significantly increased median survival time versus placebo from 7 days to 13 and 11 days, respectively. Furthermore, administration of 104 mg/kg fosmanogepix resulted in an ∼2-log10 reduction in lung, kidney, or brain conidial equivalents/gram tissue (CE). Similarly, in the fusariosis model, 78 mg/kg and 104 mg/kg fosmanogepix plus ABT enhanced median survival time from 7 days to 12 and 10 days, respectively. A 2- to 3-log10 reduction in kidney and brain CE was observed. In both models, reduction in tissue fungal burden was corroborated with histopathological data, with target organs showing reduced or no abscesses in fosmanogepix-treated mice. Survival and tissue clearance were comparable to a clinically relevant high dose of liposomal amphotericin B (10 to 15 mg/kg). Our data support the continued development of fosmanogepix as a first-in-class treatment for infections caused by these rare molds.

Galactomannan Is a Biomarker of Fosmanogepix (APX001) Efficacy in Treating Experimental Invasive Pulmonary Aspergillosis.

Galactomannan (GM) detection in biological samples has been shown to predict therapeutic response by azoles and polyenes. In a murine invasive pulmonary aspergillosis model, fosmanogepix or posaconazole treatment resulted in an ∼6- to 7-log reduction in conidial equivalents (CE)/g lung tissue after 96 h versus placebo. Changes in GM levels in BAL fluid and serum mirrored reductions in lung CE, with significant decreases seen after 96 h or 72 h for fosmanogepix or posaconazole, respectively (P < 0.02).

NDV-3A vaccination prevents C. albicans colonization of jugular vein catheters in mice.

NDV-3A, a novel fungal vaccine undergoing clinical trials, contains a recombinant version of the Candida albicans rAls3 N-terminus protein (rAls3p-N) in aluminum hydroxide. In a Phase 1b/2a clinical trial, NDV-3A protected women from recurrent vulvovaginal candidiasis. Here, we reveal that active immunization in mice with NDV-3A induces high titers of anti-rAls3p-N antibodies that interfere with C. albicans ability to adhere to and invade endothelial cells, and form biofilm in vitro. Anti-rAls3p-N antibodies also significantly inhibit yeast dispersal from the hyphal layers of biofilms. Compared to placebo, NDV-3A vaccination inhibited C. albicans dissemination to kidneys and prevented colonization of central venous catheters in mice. Overall, these preclinical studies suggest that NDV-3A may serve as an immunotherapeutic strategy for prevention of infections on indwelling medical devices.

APX001 Is Effective in the Treatment of Murine Invasive Pulmonary Aspergillosis.

Invasive pulmonary aspergillosis (IPA) due to Aspergillus fumigatus is a serious fungal infection in the immunosuppressed patient population. Despite the introduction of new antifungal agents, mortality rates remain high, and new treatments are needed. The novel antifungal APX001A targets the conserved Gwt1 enzyme required for the localization of glycosylphosphatidylinositol-anchored mannoproteins in fungi. We evaluated the in vitro activity of APX001A against A. fumigatus and the in vivo activity of its prodrug APX001 in an immunosuppressed mouse model of IPA. APX001A inhibited the growth of A. fumigatus with a minimum effective concentration of 0.03 µg/ml. The use of 50 mg/kg 1-aminobenzotriazole (ABT), a suicide inhibitor of cytochrome P450 enzymes, enhanced APX001A exposures (area under the time-concentration curve [AUC]) 16- to 18-fold and enhanced serum half-life from ∼1 to 9 h, more closely mimicking human pharmacokinetics. We evaluated the efficacy of APX001 (with ABT) in treating murine IPA compared to posaconazole treatment. Treatment of mice with 78 mg/kg once daily (QD), 78 mg/kg twice daily, or 104 mg/kg QD APX001 significantly enhanced the median survival time and prolonged day 21 postinfection overall survival compared to the placebo. Furthermore, administration of APX001 resulted in a significant reduction in lung fungal burden (4.2 to 7.6 log10 conidial equivalents/g of tissue) versus the untreated control and resolved the infection, as judged by histopathological examination. The observed survival and tissue clearance were comparable to a clinically relevant posaconazole dose. These results warrant the continued development of APX001 as a broad-spectrum, first-in-class treatment of invasive fungal infections.

Alexidine Dihydrochloride Has Broad-Spectrum Activities against Diverse Fungal Pathogens.

Invasive fungal infections due to Candida albicans, Aspergillus fumigatus, and Cryptococcus neoformans constitute a substantial threat to hospitalized immunocompromised patients. Further, the presence of drug-recalcitrant biofilms on medical devices and emergence of drug-resistant fungi, such as Candida auris, introduce treatment challenges with current antifungal drugs. Worse, currently there is no approved drug capable of obviating preformed biofilms, which increase the chance of infection relapses. Here, we screened a small-molecule New Prestwick Chemical Library, consisting of 1,200 FDA-approved off-patent drugs against C. albicans, C. auris, and A. fumigatus, to identify those that inhibit growth of all three pathogens. Inhibitors were further prioritized for their potency against other fungal pathogens and their ability to kill preformed biofilms. Our studies identified the bis-biguanide alexidine dihydrochloride (AXD) as a drug with the highest antifungal and antibiofilm activity against a diverse range of fungal pathogens. Finally, AXD significantly potentiated the efficacy of fluconazole against biofilms, displayed low mammalian cell toxicity, and eradicated biofilms growing in mouse central venous catheters in vivo, highlighting its potential as a pan-antifungal drug.IMPORTANCE The prevalence of fungal infections has seen a rise in the past decades due to advances in modern medicine leading to an expanding population of device-associated and immunocompromised patients. Furthermore, the spectrum of pathogenic fungi has changed, with the emergence of multidrug-resistant strains such as C. auris High mortality related to fungal infections points to major limitations of current antifungal therapy and an unmet need for new antifungal drugs. We screened a library of repurposed FDA-approved inhibitors to identify compounds with activities against a diverse range of fungi in varied phases of growth. The assays identified alexidine dihydrochloride (AXD) to have pronounced antifungal activity, including against preformed biofilms, at concentrations lower than mammalian cell toxicity. AXD potentiated the activity of fluconazole and amphotericin B against Candida biofilms in vitro and prevented biofilm growth in vivo Thus, AXD has the potential to be developed as a pan-antifungal, antibiofilm drug.

Iron restriction inside macrophages regulates pulmonary host defense against Rhizopus species.

Mucormycosis is a life-threatening respiratory fungal infection predominantly caused by Rhizopus species. Mucormycosis has incompletely understood pathogenesis, particularly how abnormalities in iron metabolism compromise immune responses. Here we show how, as opposed to other filamentous fungi, Rhizopus spp. establish intracellular persistence inside alveolar macrophages (AMs). Mechanistically, lack of intracellular swelling of Rhizopus conidia results in surface retention of melanin, which induces phagosome maturation arrest through inhibition of LC3-associated phagocytosis. Intracellular inhibition of Rhizopus is an important effector mechanism, as infection of immunocompetent mice with swollen conidia, which evade phagocytosis, results in acute lethality. Concordantly, AM depletion markedly increases susceptibility to mucormycosis. Host and pathogen transcriptomics, iron supplementation studies, and genetic manipulation of iron assimilation of fungal pathways demonstrate that iron restriction inside macrophages regulates immunity against Rhizopus. Our findings shed light on the pathogenetic mechanisms of mucormycosis and reveal the role of macrophage-mediated nutritional immunity against filamentous fungi.

A Fungal Immunotherapeutic Vaccine (NDV-3A) for Treatment of Recurrent Vulvovaginal Candidiasis-A Phase 2 Randomized, Double-Blind, Placebo-Controlled Trial.

Background: Recurrent vulvovaginal candidiasis (RVVC) is a problematic form of mucosal Candida infection, characterized by repeated episodes per year. Candida albicans is the most common cause of RVVC. Currently, there are no immunotherapeutic treatments for RVVC. Methods: This exploratory randomized, double-blind, placebo-controlled trial evaluated an immunotherapeutic vaccine (NDV-3A) containing a recombinant C. albicans adhesin/invasin protein for prevention of RVVC. Results: The study in 188 women with RVVC (n = 178 evaluable) showed that 1 intramuscular dose of NDV-3A was safe and generated rapid and robust B- and T-cell immune responses. Post hoc exploratory analyses revealed a statistically significant increase in the percentage of symptom-free patients at 12 months after vaccination (42% vaccinated vs 22% placebo; P = .03) and a doubling in median time to first symptomatic episode (210 days vaccinated vs 105 days placebo) for the subset of patients aged <40 years (n = 137). The analysis of evaluable patients, which combined patients aged <40 years (77%) and ≥40 years (23%), trended toward a positive impact of NDV-3A versus placebo (P = .099). Conclusions: In this unprecedented study of the effectiveness of a fungal vaccine in humans, NDV-3A administered to women with RVVC was safe and highly immunogenic and reduced the frequency of symptomatic episodes of vulvovaginal candidiasis for up to 12 months in women aged <40 years. These results support further development of NDV-3A vaccine and provide guidance for meaningful clinical endpoints for immunotherapeutic management of RVVC. Clinical Trials Registration: NCT01926028.

Calli Essential Oils Synergize with Lawsone against Multidrug Resistant Pathogens.

The fast development of multi-drug resistant (MDR) organisms increasingly threatens global health and well-being. Plant natural products have been known for centuries as alternative medicines that can possess pharmacological characteristics, including antimicrobial activities. The antimicrobial activities of essential oil (Calli oil) extracted from the Calligonum comosum plant by hydro-steam distillation was tested either alone or when combined with lawsone, a henna plant naphthoquinone, against MDR microbes. Lawsone showed significant antimicrobial activities against MDR pathogens in the range of 200-300 µg/mL. Furthermore, Calli oil showed significant antimicrobial activities against MDR bacteria in the range of 180-200 µg/mL, Candida at 220-240 µg/mL and spore-forming Rhizopus fungus at 250 µg/mL. Calli oil's inhibition effect on Rhizopus, the major cause of the lethal infection mucormycosis, stands for 72 h, followed by an extended irreversible white sporulation effect. The combination of Calli oil with lawsone enhanced the antimicrobial activities of each individual alone by at least three-fold, while incorporation of both natural products in a liposome reduced their toxicity by four- to eight-fold, while maintaining the augmented efficacy of the combination treatment. We map the antimicrobial activity of Calli oil to its major component, a benzaldehyde derivative. The findings from this study demonstrate that formulations containing essential oils have the potential in the future to overcome antimicrobial resistance.

Prophylactic Treatment with VT-1161 Protects Immunosuppressed Mice from Rhizopus arrhizus var. arrhizus Infection.

We compared prophylactic or continuous therapy with the investigational drug VT-1161 to that with posaconazole in treating murine mucormycosis due to Rhizopus arrhizus var. arrhizus In the prophylaxis studies, only VT-1161 resulted in improved survival and lowered tissue fungal burden of immunosuppressed infected mice. In the continuous therapy, VT-1161 outperformed posaconazole in prolonging mouse survival time despite its comparable effect in lowering tissue fungal burden. These results support the further development of VT-1161 against mucormycosis.

Assessment of herbal drugs for promising anti-Candida activity.

BACKGROUND: Microbial infections are diverse and cause serious human diseases. Candida albicans infections are serious healthcare-related infections that are complicated by its morphological switching from yeast to hyphae, resistant biofilm formation and mixed infections with bacteria. Due to the increase in drug resistance to currently used antimicrobial agents and the presence of undesirable side effects, the need for safe and effective novel therapies is important. Compounds derived from plants are known for their medicinal properties including antimicrobial activities. The purpose of the study was to compare and evaluate the anti-Candida activities of several medicinal plants in order for the selection of a herbal drug for human use as effective antimicrobial. The selection was taking into considerations two important parameters; parameters related to the selected drug including activity, stability, solubility and toxicity and parameters related to the pathogen including its different dynamic growth and its accompanied secondary bacterial infections. METHODS: Seven different plants including Avicennia marina (Qurm), Fagonia indica (Shoka'a), Lawsania inermis (Henna), Portulaca oleracea (Baq'lah), Salvadora persica (Souwak), Ziziphus spina- Christi (Sidr) and Asphodelus tenuifolius (Kufer) were ground and extracted with ethanol. The ethanol extracts were evaporated and the residual extract dissolved in water prior to testing against Candida albicans in its different morphologies. The antibacterial and cytotoxic effects of the plants extracts were also tested. RESULTS: Out of the seven tested plants, L. inermis and P. oleracea showed significant anti-Candida activity with MIC ~10 µg/mL. Furthermore, both plant extracts were able to inhibit C. albicans growth at its dynamic growth phases including biofilm formation and age resistance. Accompanied secondary bacterial infections can complicate Candida pathogenesis. L. inermis and P. oleracea extracts showed effective antibacterial activities against S. aureus, P. aeruginosa, E. coli, and the multidrug resistant (MDR) A. baumannii and Klebsiella pneumoniae. Both extracts showed no toxicity when measured at their MIC on human erythrocytes. CONCLUSION: The results from this study suggested that L. inermis and P. oleracea extracts and/or their chemicals are likely to be promising drugs for human use against C. albicans and MDR bacteria.

Monotherapy or combination therapy of isavuconazole and micafungin for treating murine mucormycosis.

OBJECTIVES: Previously we demonstrated the benefit of isavuconazole in treating murine mucormycosis due to Rhizopus. We wanted to determine the efficacy of isavuconazole in treating murine mucormycosis caused by Mucor, the second most common cause of the disease. Furthermore, because we previously determined that Rhizopus possesses the target enzyme for echinocandins and micafungin has activity against murine mucormycosis, we compared the activity of combination therapy (isavuconazole + micafungin) with placebo, either drug alone or standard therapy of liposomal amphotericin B (LAmB) in treating pulmonary murine mucormycosis caused by Rhizopus delemar. METHODS: In vitro susceptibility to isavuconazole of Mucorales was evaluated using the CLSI M38-A2 method. Immunosuppressed mice were intratracheally infected with either Mucor circinelloides or R. delemar. Treatment with isavuconazole (orally), micafungin (intraperitoneally), a combination of both or LAmB (intravenously) was compared, with survival and tissue fungal burden serving as primary and secondary endpoints, respectively. RESULTS: Isavuconazole was as effective as LAmB in prolonging survival of mice infected with M. circinelloides. Against R. delemar-induced mucormycosis, all monotherapy treatments significantly improved survival of mice versus placebo without showing superiority over one another. However, LAmB was superior in lowering fungal burden in target organs. Although combination therapy of isavuconazole + micafungin did not enhance survival of mice over monotherapy, antagonism was not detected between the two drugs. CONCLUSION: Isavuconazole is effective in treating pulmonary murine mucormycosis due to Mucor. In addition, combination therapy of isavuconazole + micafungin does not demonstrate synergy and it is not antagonistic against Rhizopus-induced mucormycosis.

Bicarbonate correction of ketoacidosis alters host-pathogen interactions and alleviates mucormycosis.

Patients with diabetic ketoacidosis (DKA) are uniquely predisposed to mucormycosis, an angioinvasive fungal infection with high mortality. Previously, we demonstrated that Rhizopus invades the endothelium via binding of fungal CotH proteins to the host receptor GRP78. Here, we report that surface expression of GRP78 is increased in endothelial cells exposed to physiological concentrations of ß-hydroxy butyrate (BHB), glucose, and iron that are similar to those found in DKA patients. Additionally, expression of R. oryzae CotH was increased within hours of incubation with DKA-associated concentrations of BHB, glucose, and iron, augmenting the ability of R. oryzae to invade and subsequently damage endothelial cells in vitro. BHB exposure also increased fungal growth and attenuated R. oryzae neutrophil-mediated damage. Further, mice given BHB developed clinical acidosis and became extremely susceptible to mucormycosis, but not aspergillosis, while sodium bicarbonate reversed this susceptibility. BHB-related acidosis exerted a direct effect on both GRP78 and CotH expression, an effect not seen with lactic acidosis. However, BHB also indirectly compromised the ability of transferrin to chelate iron, as iron chelation combined with sodium bicarbonate completely protected endothelial cells from Rhizopus-mediated invasion and damage. Our results dissect the pathogenesis of mucormycosis during ketoacidosis and reinforce the importance of careful metabolic control of the acidosis to prevent and manage this infection.

Statin Concentrations Below the Minimum Inhibitory Concentration Attenuate the Virulence of Rhizopus oryzae.

BACKGROUND: Mucormycosis is a destructive invasive mold infection afflicting patients with diabetes and hematologic malignancies. Patients with diabetes are often treated with statins, which have been shown to have antifungal properties. We sought to examine the effects of statins on Rhizopus oryzae, a common cause of mucormycosis. METHODS: Clinical strains of R. oryzae were exposed to lovastatin, atorvastatin, and simvastatin and the minimum inhibitory concentrations (MICs) were determined. R. oryzae germination, DNA fragmentation, susceptibility to oxidative stress, and ability to damage endothelial cells were assessed. We further investigated the impact of exposure to lovastatin on the virulence of R. oryzae RESULTS: All statins had MICs of >64 µg/mL against R. oryzae Exposure of R. oryzae to statins decreased germling formation, induced DNA fragmentation, and attenuated damage to endothelial cells independently of the expression of GRP78 and CotH. Additionally, R. oryzae exposed to lovastatin showed macroscopic loss of melanin, yielded increased susceptibility to the oxidative agent peroxide, and had attenuated virulence in both fly and mouse models of mucormycosis. CONCLUSIONS: Exposure of R. oryzae to statins at concentrations below their MICs decreased virulence both in vitro and in vivo. Further investigation is warranted into the use of statins as adjunctive therapy in mucormycosis.

Fob1 and Fob2 Proteins Are Virulence Determinants of Rhizopus oryzae via Facilitating Iron Uptake from Ferrioxamine.

Dialysis patients with chronic renal failure receiving deferoxamine for treating iron overload are uniquely predisposed for mucormycosis, which is most often caused by Rhizopus oryzae. Although the deferoxamine siderophore is not secreted by Mucorales, previous studies established that Rhizopus species utilize iron from ferrioxamine (iron-rich form of deferoxamine). Here we determined that the CBS domain proteins of Fob1 and Fob2 act as receptors on the cell surface of R. oryzae during iron uptake from ferrioxamine. Fob1 and Fob2 cell surface expression was induced in the presence of ferrioxamine and bound radiolabeled ferrioxamine. A R. oryzae strain with targeted reduced Fob1/Fob2 expression was impaired for iron uptake, germinating, and growing on medium with ferrioxamine as the sole source of iron. This strain also exhibited reduced virulence in a deferoxamine-treated, but not the diabetic ketoacidotic (DKA), mouse model of mucormycosis. The mechanism by which R. oryzae obtains iron from ferrioxamine involves the reductase/permease uptake system since the growth on ferrioxamine supplemented medium is associated with elevated reductase activity and the use of the ferrous chelator bathophenanthroline disulfonate abrogates iron uptake and growth on medium supplemented with ferrioxamine as a sole source of iron. Finally, R. oryzae mutants with reduced copies of the high affinity iron permease (FTR1) or with decreased FTR1 expression had an impaired iron uptake from ferrioxamine in vitro and reduced virulence in the deferoxamine-treated mouse model of mucormycosis. These two receptors appear to be conserved in Mucorales, and can be the subject of future novel therapy to maintain the use of deferoxamine for treating iron-overload.

Efficacy of liposomal amphotericin B and posaconazole in intratracheal models of murine mucormycosis.

Mucormycosis is a life-threatening fungal infection almost uniformly affecting diabetics in ketoacidosis or other forms of acidosis and/or immunocompromised patients. Inhalation of Mucorales spores provides the most common natural route of entry into the host. In this study, we developed an intratracheal instillation model of pulmonary mucormycosis that hematogenously disseminates into other organs using diabetic ketoacidotic (DKA) or cyclophosphamide-cortisone acetate-treated mice. Various degrees of lethality were achieved for the DKA or cyclophosphamide-cortisone acetate-treated mice when infected with different clinical isolates of Mucorales. In both DKA and cyclophosphamide-cortisone acetate models, liposomal amphotericin B (LAmB) or posaconazole (POS) treatments were effective in improving survival, reducing lungs and brain fungal burdens, and histologically resolving the infection compared with placebo. These models can be used to study mechanisms of infection, develop immunotherapeutic strategies, and evaluate drug efficacies against life-threatening Mucorales infections.

Pathogenesis of mucormycosis.

Mucormycosis is a life-threatening infection that occurs in patients who are immunocompromised because of diabetic ketoacidosis, neutropenia, organ transplantation, and/or increased serum levels of available iron. Because of the increasing prevalence of diabetes mellitus, cancer, and organ transplantation, the number of patients at risk for this deadly infection is increasing. Despite aggressive therapy, which includes disfiguring surgical debridement and frequently adjunctive toxic antifungal therapy, the overall mortality rate is high. New strategies to prevent and treat mucormycosis are urgently needed. Understanding the pathogenesis of mucormycosis and the host response to invading hyphae ultimately will provide targets for novel therapeutic interventions. In this supplement, we review the current knowledge about the virulence traits used by the most common etiologic agent of mucormycosis, Rhizopus oryzae. Because patients with elevated serum levels of available iron are uniquely susceptible to mucormycosis and these infections are highly angioinvasive, emphasis is placed on the ability of the organism to acquire iron from the host and on its interactions with endothelial cells lining blood vessels. Several promising therapeutic strategies in preclinical stages are identified.

The Deferasirox-AmBisome Therapy for Mucormycosis (DEFEAT Mucor) study: a randomized, double-blinded, placebo-controlled trial.

OBJECTIVES: Host iron availability is fundamental to mucormycosis pathogenesis. The combination of liposomal amphotericin B (LAmB) and deferasirox iron chelation therapy synergistically improved survival in diabetic mice with mucormycosis. To determine the safety of combination deferasirox plus LAmB therapy for mucormycosis, a multicentred, placebo-controlled, double-blinded clinical trial was conducted. METHODS: Twenty patients with proven or probable mucormycosis were randomized to receive treatment with LAmB plus deferasirox (20 mg/kg/day for 14 days) or LAmB plus placebo (NCT00419770, clinicaltrials.gov). The primary analyses were for safety and exploratory efficacy. RESULTS: Patients in the deferasirox arm (n=11) were more likely than those in the placebo arm (n=9) to have active malignancy, neutropenia and corticosteroid therapy, and were less likely to receive concurrent non-study antifungal therapy. Reported adverse events and serious adverse events were similar between the groups. However, death was more frequent in the deferasirox than in the placebo arm at 30 days (45% versus 11%, P=0.1) and 90 days (82% versus 22%, P=0.01). Global success (alive, clinically stable, radiographically improved) for the deferasirox arm versus the placebo arm at 30 and 90 days, respectively, was 18% (2/11) versus 67% (6/9) (P=0.06) and 18% (2/11) versus 56% (5/9) (P=0.2). CONCLUSIONS: Patients with mucormycosis treated with deferasirox had a higher mortality rate at 90 days. Population imbalances in this small Phase II study make generalizable conclusions difficult. Nevertheless, these data do not support a role for initial, adjunctive deferasirox therapy for mucormycosis.

The iron chelator deferasirox enhances liposomal amphotericin B efficacy in treating murine invasive pulmonary aspergillosis.

OBJECTIVES: Increased bone marrow iron levels in patients with haematological malignancies is an independent risk factor for developing invasive pulmonary aspergillosis (IPA), suggesting an important role for iron uptake in the pathogenesis of IPA. We sought to determine the potential for combination therapy with the iron chelator deferasirox + liposomal amphotericin B (LAmB) to improve the outcome of murine IPA compared with LAmB monotherapy. METHODS: In vitro MIC and minimum fungicidal concentration (MFC) values of the iron chelator, deferasirox, for Aspergillus fumigatus were determined by microdilution assay. In addition, we studied the efficacy of deferasirox alone or combined with LAmB in treating immunocompromised mice infected with A. fumigatus via inhalation. RESULTS: Deferasirox was cidal in vitro against A. fumigatus, with an MIC and MFC of 25 and 50 mg/L, respectively. Deferasirox monotherapy modestly prolonged survival of mice with IPA. Combination deferasirox + LAmB therapy synergistically improved survival and reduced lung fungal burden compared with either monotherapy alone. CONCLUSIONS: Iron chelation therapy with deferasirox alone or in combination with LAmB is effective in treating experimental IPA. Further study of deferasirox is warranted as adjunctive therapy for IPA infections.