Comparison of fungizone, Amphotec, AmBisome, and Abelcet for treatment of systemic murine cryptococcosis

Advances in functional lipid nanoparticles: from drug delivery platforms to clinical applications

Since Doxil's first clinical approval in 1995, lipid nanoparticles have garnered great interest and shown exceptional therapeutic efficacy. It is clear from the licensure of two RNA treatments and the mRNA-COVID-19 vaccination that lipid nanoparticles have immense potential for delivering nucleic acids. The review begins with a list of lipid nanoparticle types, such as liposomes and solid lipid nanoparticles. Then it moves on to the earliest lipid nanoparticle forms, outlining how lipid is used in a variety of industries and how it is used as a versatile nanocarrier platform. Lipid nanoparticles must then be functionally modified. Various approaches have been proposed for the synthesis of lipid nanoparticles, such as High-Pressure Homogenization (HPH), microemulsion methods, solvent-based emulsification techniques, solvent injection, phase reversal, and membrane contractors. High-pressure homogenization is the most commonly used method. All of the methods listed above follow four basic steps, as depicted in the flowchart below. Out of these four steps, the process of dispersing lipids in an aqueous medium to produce liposomes is the most unpredictable step. A short outline of the characterization of lipid nanoparticles follows discussions of applications for the trapping and transporting of various small molecules. It highlights the use of rapamycin-coated lipid nanoparticles in glioblastoma and how lipid nanoparticles function as a conjugator in the delivery of anticancer-targeting nucleic acids. High biocompatibility, ease of production, scalability, non-toxicity, and tailored distribution are just a meager of the enticing allowances of using lipid nanoparticles as drug delivery vehicles. Due to the present constraints in drug delivery, more research is required to utterly realize the potential of lipid nanoparticles for possible clinical and therapeutic purposes.

Radioimmunotherapy as a pathogen-agnostic treatment method for opportunistic mucormycosis infections

Invasive fungal infections (IFIs) such as mucormycosis are causing devastating morbidity and mortality in immunocompromised patients as anti-fungal agents do not work in the setting of a suppressed immune system. The coronavirus disease 2019 (COVID-19) pandemic has created a novel landscape for IFIs in post-pandemic patients, resulting from severe immune suppression caused by COVID-19 infection, comorbidities (diabetes, obesity) and immunosuppressive treatments such as steroids. The antigen-antibody interaction has been employed in radioimmunotherapy (RIT) to deliver lethal doses of ionizing radiation emitted by radionuclides to targeted cells and has demonstrated efficacy in several cancers. One of the advantages of RIT is its independence of the immune status of a host, which is crucial for immunosuppressed post-COVID-19 patients. In the present work we targeted the fungal pan-antigens 1,3-beta-glucan and melanin pigment, which are present in the majority of pathogenic fungi, with RIT, thus making such targeting pathogen-agnostic. We demonstrated in experimental murine mucormycosis in immunocompetent and immunocompromised mice that lutetium-177 (177Lu)-labelled antibodies to these two antigens effectively decreased the fungal burden in major organs, including the brain. These results are encouraging because they show the effectiveness of pathogen-agnostic RIT in significantly decreasing fungal burden in vivo, while they can also potentially be applied to treat the broad range of invasive fungal infections that express the pan-antigens 1,3-beta-glucan or melanin.

Lipid-Based Nanoparticles for Drug/Gene Delivery: An Overview of the Production Techniques and Difficulties Encountered in Their Industrial Development

Over the past decade, the therapeutic potential of nanomaterials as novel drug delivery systems complementing conventional pharmacology has been widely acknowledged. Among these nanomaterials, lipid-based nanoparticles (LNPs) have shown remarkable pharmacological performance and promising therapeutic outcomes, thus gaining substantial interest in preclinical and clinical research. In this review, we introduce the main types of LNPs used in drug formulations such as liposomes, nanoemulsions, solid lipid nanoparticles, nanostructured lipid carriers, and lipid polymer hybrid nanoparticles, focusing on their main physicochemical properties and therapeutic potential. We discuss computational studies and modeling techniques to enhance the understanding of how LNPs interact with therapeutic cargo and to predict the potential effectiveness of such interactions in therapeutic applications. We also analyze the benefits and drawbacks of various LNP production techniques such as nanoprecipitation, emulsification, evaporation, thin film hydration, microfluidic-based methods, and an impingement jet mixer. Additionally, we discuss the major challenges associated with industrial development, including stability and sterilization, storage, regulatory compliance, reproducibility, and quality control. Overcoming these challenges and facilitating regulatory compliance represent the key steps toward LNP's successful commercialization and translation into clinical settings.

Engineering Telodendrimer Nanocarriers for Monomeric Amphotericin B Delivery

Systemic fungal infections are an increasingly prevalent health problem. Amphotericin B (AmB), a hydrophobic polyene antibiotic, remains the drug of choice for life-threatening invasive fungal infections. However, it has dose-limiting side effects, including nephrotoxicity. The efficacy and toxicity of AmB are directly related to its aggregation state. Here, we report the preparation of a series of telodendrimer (TD) nanocarriers with the freely engineered core structures for AmB encapsulation to fine-tune AmB aggregation status. The reduced aggregation status correlates well with the optimized antifungal activity, attenuated hemolytic properties, and reduced cytotoxicity to mammalian cells. The optimized TD nanocarrier for monomeric AmB encapsulation significantly increases the therapeutic index, reduces the in vivo toxicity, and enhances antifungal effects in mouse models with Candida albicans infection in comparison to two common clinical formulations, i.e., Fungizone and AmBisome.

- Amphotericin B: A drug of choice for Visceral Leishmaniasis

Visceral leishmaniasis or Kala-azar is a vector-borne disease caused by an intracellular parasite of the genus leishmania. In India, Amphotericin B (AmB) is a first-line medication for treating leishmaniasis. After a large-scale resistance to pentavalent antimony therapy developed in Bihar state, it was rediscovered as an effective treatment for Leishmania donovani infection. AmB which binds to the ergosterol of protozoan cells causes a change in membrane integrity resulting in ions leakage, and ultimately leading to cell death. The treatment effect of liposomal AmB can be seen more quickly than deoxycholate AmB because, it has some toxic effects, but liposomal AmB is significantly less toxic. Evidence from studies suggested that ABLC (Abelcet) and ABCD (Amphotec) are as effective as L-AmB but Liposomal form (Ambisome) is a more widely accepted treatment option than conventional ones. Nevertheless, the world needs some way more efficient antileishmanial drugs that are less toxic and less expensive for people living with parasitic infections caused by Leishmania. So, academics, researchers, and sponsors need to focus on finding such drugs. This review provides a summary of the chemical, pharmacokinetic, drug-target interactions, stability, dose efficacy, and many other characteristics of the AmB and their various formulations. We have also highlighted the clinically significant aspects of PKDL and VL co-infection with HIV/TB.

Polyene Antibiotics Physical Chemistry and Their Effect on Lipid Membranes; Impacting Biological Processes and Medical Applications

This review examined a collection of studies regarding the molecular properties of some polyene antibiotic molecules as well as their properties in solution and in particular environmental conditions. We also looked into the proposed mechanism of action of polyenes, where membrane properties play a crucial role. Given the interest in polyene antibiotics as therapeutic agents, we looked into alternative ways of reducing their collateral toxicity, including semi-synthesis of derivatives and new formulations. We follow with studies on the role of membrane structure and, finally, recent developments regarding the most important clinical applications of these compounds.

Fungal Endophthalmitis in a Case of Rhino-Orbito-Cerebral Mucormycosis: Successfully Treated With Amphotericin B Colloidal Dispersion

Background

Rhino-orbito-cerebral mucormycosis (ROCM) is an acute, fulminant, opportunistic fungal infection that usually occurs in diabetes or immunocompromised patients. Amphotericin B combined with surgical debridement remains the standard treatment, although it is controversial due to its lager nephrotoxicity. Thus far, no studies have reported the treatment for ROCM-associated fungal endophthalmitis because the exact pathogenesis and transmission routes in ROCM remain unclear. Here, we reported a case of ROCM complicated with fungal endophthalmitis treated favorably with amphotericin B colloidal dispersion (ABCD) in combination with other antifungals and surgical debridement.

Case Presentation

A 34-year-old woman with diabetes was admitted to our hospital owing to right-sided headache for 8 days, blindness with swelling in the right eye for 5 days, and blindness in the left eye for 1 day. MRI showed that the patient had sphenoid sinus, sinuses, frontal lobe lesions, and proptosis of the right eye. Metagenomic sequencing revealed that the patient had Rhizopus oryzae infection. During hospitalization, the patient received intravenous ABCD, oral posaconazole, and topical amphotericin B and underwent surgical debridement. After 67 days of treatment, the patient’s condition was significantly improved, and limb muscle strength showed grade V. Rhizopus oryzae showed negative results, and conjunctival swelling decreased. Additionally, no nephrotoxicity occurred during treatment. After discharge, the patient’s treatment was transitioned to oral posaconazole and she was free of complaints during the 30-day follow-up without any additional treatment for ROCM.

Conclusion

Treatment with ABCD combined with other antifungal drugs and surgical debridement for ROCM complicated with fungal endophthalmitis showed remarkable efficacy and good safety. Hence, this regimen is a promising treatment strategy for this fatal disease.

Complexing amphotericin B with gold nanoparticles improves fungal clearance from the brains of mice infected with Cryptococcal neoformans

Amphotericin B (AmB) is used to treat cryptococcal meningoencephalitis. However, the mortality rate remains high. Higher doses of AmB in deoxycholate buffer (AmBd) are toxic to human red blood cells (hRBC) and have no effect on brain organism load in mice. Here we show that while AmBd lysed 96% of hRBC, AmB complexed with gold nanoparticles (AuNP-SA-AmB) lysed only 27% of hRBC. In vitro growth of C. neoformans was inhibited by 0.25 μg/ml AmBd and 0.04 μg/ml of AuNP-SA-AmB. In mice infected with C. neoformans, five daily treatments with AuNP-SA-AmB containing 0.25 mg/kg AmB significantly lowered the fungal burden in the brain tissue compared to either untreated or treatment with 0.25 mg/kg of AmBd. When a single dose of AmBd was injected intravenously into BALB/c mice, 81.61% of AmB cleared in the α-phase and 18.39% cleared in the β-phase at a rate of 0.34% per hour. In contrast, when AuNP-SA-AmB was injected, 49.19% of AmB cleared in the α-phase and 50.81% of AmB cleared in the β-phase at a rate of 0.27% per hour. These results suggest that AmB complexed with gold nanoparticles is less toxic to hRBC, is more effective against C. neoformans and persists longer in blood when injected into mice resulting in more effective clearing of C. neoformans from the brain tissue.

LAY SUMMARY

Amphotericin B (AmB) was complexed with gold nanoparticles (AuNP-SA-AmB) to improve brain delivery. AuNP-SA-AmB was more effective than AmB alone in clearing of Cryptococcus neoformans from the brain tissue of infected mice. This may be due to longer plasma half-life of AmB as AuNP-SA-AmB.

Scalable Production of Lipid Nanoparticles Containing Amphotericin B

Lipid-based formulations have been developed to improve stability profiles, tolerability, and toxicity profiles of small molecule drugs. However, manufacture of such formulations involving lipophilic compounds can be labor-intensive and difficult to scale because of solubility and solvent compatibility issues. We have developed a rapid and scalable approach using rapid-mixing techniques to generate homogeneous lipid nanoparticle (LNP) formulations of siRNA, triglycerides, and hydrophilic weak-base drugs. Here, we used this approach to entrap a hydrophobic small molecule, Amphotericin B (AmpB), a hydrophobic drug not soluble in ethanol. The three prototypes presented in this study were derived from LNP-siRNA systems, triglyceride nanoparticles, and liposomal systems. Cryogenic transmission electron microscopy (cryo-TEM) revealed that all three LNP-AmpB formulations retain structural characteristics of the parent (AmpB-free) LNPs, with particles remaining stable for at least 1 month. All formulations showed similar in vitro toxicity profiles in comparison to AmBisome. Importantly, the formulations have a 2.5-fold improved IC₅₀ for fungal growth inhibition as compared to AmBisome in in vitro efficacy studies. These results demonstrate that the rapid-mixing technology combined with dimethyl sulfoxide (DMSO) for drugs insoluble in other organic solvents can be a powerful manufacturing method for the generation of stable LNP drug formulations.

A highly sensitive and specific method to evaluate viable fungal burden of Aspergillus fumigatus in mice by RT-qPCR for 18S ribosomal RNA

Potent fungicidal activity is one of the key factors of antifungals to overcome invasive pulmonary aspergillosis (IPA). To date, quantification of Aspergillus DNA in the lungs and galactomannan (GM) in serum or bronchoalveolar lavage fluid have been developed as general methods for measuring fungal burden in IPA animal models. However, GM quantification is not supposed to be a suitable method for precise evaluation of the fungicidal effects of antifungals, because killed Aspergillus hyphae can release GM for a certain period until they are eliminated by the host. Therefore, in terms of detecting viable fungal burden of Aspergillus, quantification of Aspergillus DNA has been thought to be a suitable method. Here, to obtain a method with much higher sensitivity, we applied reverse transcription quantitative PCR (RT-qPCR) for A. fumigatus 18S ribosomal RNA to measure the viable fungal burden in murine IPA models. Prior to in vivo tests, we confirmed that the sensitivity of 18S rRNA was nearly 50-fold higher than that of 18S ribosomal DNA in vitro. This highly sensitive method made it possible to evaluate the fungicidal effects of antifungals in a low-inoculation murine IPA model. In this model, single administrations of higher doses of voriconazole and posaconazole, which have fungicidal activity, were able to display fungicidal effects with ≥1 log₁₀ reductions by 18S rRNA quantification, whereas significant reductions in serum GM were not observed. These results suggest that 18S rRNA quantification is a powerful tool for screening novel antifungals with potent fungicidal activity only after a single administration.

Preclinical Safety, Tolerability, Pharmacokinetics, Pharmacodynamics, and Antifungal Activity of Liposomal Amphotericin B

The improved safety profile and antifungal efficacy of liposomal amphotericin B (LAmB) compared to conventional amphotericin B deoxycholate (DAmB) is due to several factors including, its chemical composition, rigorous manufacturing standards, and ability to target and transit through the fungal cell wall. Numerous preclinical studies have shown that LAmB administered intravenously distributes to tissues frequently infected by fungi at levels above the minimum inhibitory concentration (MIC) for many fungi. These concentrations can be maintained from one day to a few weeks, depending upon the tissue. Tissue accumulation is dose-dependent with drug clearance occurring most rapidly from the brain and slowest from the liver and spleen. LAmB localizes in lung epithelial lining fluid, within liver and splenic macrophages and in kidney distal tubules. LAmB has been used successfully in therapeutic and prophylactic animal models to treat many different fungal pathogens, significantly increasing survival and reducing tissue fungal burden.

Extended Dosing Regimens for Fungal Prophylaxis

Invasive fungal diseases carry high morbidity and mortality in patients undergoing chemotherapy for hematological malignancies or allogeneic hematopoietic stem cell transplantation. In order to prevent these life-threatening infections, antifungal chemoprophylaxis plays an important role in daily clinical practice. Broad-spectrum antifungal triazoles are widely used but exhibit disadvantages such as relevant drug-drug interactions. Therefore, amphotericin B products or echinocandins can be an alternative in selected patient populations. As these compounds are available as intravenous formulations only, there is growing interest in extended dosing regimens. Although not approved for these agents, this strategy is a rational option, as these compounds have properties suitable for this strategy, including dose-proportional pharmacokinetics, prolonged elimination half-life, and a large therapeutic window. As the use of extended dosing regimens in antifungal prophylaxis is expanding in clinical practice, we reviewed the pharmacokinetic and pharmacodynamic rationale for this strategy, animal model data, dose escalation studies, and clinical trials supporting this concept.

Tissue pharmacokinetics and pharmacodynamics of AmBisome® (L-AmBis) in uninfected and infected animals and their effects on dosing regimens

By selecting a unique combination of lipids and amphotericin B, the liposome composition for AmBisome® (L-AmBis) has been optimized resulting in a formulation that is minimally toxic, targets to fungal cell walls, and distributes into and remains for days to weeks in various host tissues at drug levels above the MIC for many fungi. Procedures have been standardized to ensure that large scale production of the drug retains the drug's low toxicity profile, favorable pharmacokinetics and antifungal efficacy. Tissue accumulation and clearance with single or multiple intravenous administration is similar in uninfected and infected animal species, with tissue accumulation being dose-dependent and the liver and spleen retaining the most drug. The efficacy in animals appears to be correlated with drug tissue levels although the amount needed in a given organ varies depending upon the type of infection. The long-term tissue retention of bioactive L-AmBis in different organs suggests that for some indications, prophylactic and intermittent drug dosing would be efficacious reducing the cost and possible toxic side-effects. In addition, preliminary preclinical studies using non-intravenous routes of delivery, such as aerosolized L-AmBis, catheter lock therapy, and intravitreal administration, suggest that alternative routes could possibly provide additional therapeutic applications for this antifungal drug.

Liposomal Amphotericin B (AmBisome(®)): A Review of the Pharmacokinetics, Pharmacodynamics, Clinical Experience and Future Directions

Liposomal amphotericin B (AmBisome(®); LAmB) is a unique lipid formulation of amphotericin B. LAmB is a standard of care for a wide range of medically important opportunistic fungal pathogens. LAmB has a significantly improved toxicity profile compared with conventional amphotericin B deoxycholate (DAmB). Despite nearly 20 years of clinical use, the pharmacokinetics and pharmacodynamics of this agent, which differ considerably from DAmB, remain relatively poorly understood and underutilized in the clinical setting. The molecular pharmacology, preclinical and clinical pharmacokinetics, and clinical experience with LAmB for the most commonly encountered fungal pathogens are reviewed. In vitro, experimental animal models and human clinical trial data are summarized, and novel routes of administration and dosing schedules are discussed. LAmB is a formulation that results in reduced toxicity as compared with DAmB while retaining the antifungal effect of the active agent. Its long terminal half-life and retention in tissues suggest that single or intermittent dosing regimens are feasible, and these should be actively investigated in both preclinical models and in clinical trials. Significant gaps remain in knowledge of pharmacokinetics and pharmacodynamics in special populations such as neonates and children, pregnant women and obese patients.

Radiolabeled Antibodies for Therapy of Infectious Diseases

Novel approaches to the treatment of infectious diseases are urgently needed. This need has resulted in renewing the interest in antibodies for therapy of infectious diseases. Radioimmunotherapy (RIT) is a cancer treatment modality that utilizes radiolabeled monoclonal antibodies. During the last decade we have translated RIT into the field of experimental fungal, bacterial, and HIV infections. In addition, successful proof of principle experiments with radiolabeled pan-antibodies that bind to antigens shared by major pathogenic fungi have been performed in vitro. The armamentarium of pan-antibodies would result in reducing our dependence on microorganism-specific antibodies and thus would speed up the development of RIT for infections. We believe that the time is ripe for deploying RIT in the clinic to combat infectious diseases.

Cryptococcosis: epidemiology, fungal resistance, and new alternatives for treatment

Cryptococcosis is an important systemic mycosis and the third most prevalent disease in human immunodeficiency virus (HIV)-positive individuals. The incidence of cryptococcosis is high among the 25 million people with HIV/acquired immunodeficiency syndrome (AIDS), with recent estimates indicating that there are one million cases of cryptococcal meningitis globally per year in AIDS patients. In Cryptococcus neoformans, resistance to azoles may be associated with alterations in the target enzyme encoded by the gene ERG11, lanosterol 14α-demethylase. These alterations are obtained through mutations, or by overexpressing the gene encoding. In addition, C. gattii and C. neoformans present a heteroresistance phenotype, which may be related to increased virulence. Other species beyond C. neoformans and C. gattii, such as C. laurentii, have been diagnosed mainly in patients with immunosuppression. Infections of C. albidus have been isolated in cats and marine mammals. Recent evidence suggests that the majority of infections produced by this pathogen are associated with biofilm growth, which is also related with increased resistance to antifungal agents. Therefore, there is a great need to search for alternative antifungal agents for these fungi. The search for new molecules is currently occurring from nanoparticle drugs of plant peptide origin. This article presents a brief review of the literature regarding the epidemiology of cryptococcosis, as well as fungal resistance and new alternatives for treatment.

A brain-vectored angiopep-2 based polymeric micelles for the treatment of intracranial fungal infection

One of the most common life-threatening infections in immunosuppressive patients, like AIDs patients, is cryptococcal meningitis or meningoencephalitis. Current therapeutic options are mostly ineffective and mortality rates remain high. Hydrophobic antifungal drug Amphotericin B (AmB), has become a golden standard in severe systemic fungal infection therapy. However, most AmB commercial formulations, including deoxycholate AmB and lipid formulations of AmB, show poor penetration into the CNS and difficulty to reach the therapeutic levels. To improve the CNS permeability of AmB, we have successfully developed an effective brain-targeting polymeric micellar system with angiopep-2 modified, named Angiopep-PEG-PE/AmB polymeric micelles. An immunosuppressive murine model with Cryptococcus neoformans meningoencephalitis (CNME) was established to evaluate the CNS penetration efficiency and antifungal treatment efficacy of the AmB-incorporated brain-vectored polymeric micellar formulation, compared with the AmB commercial formulations. After three consecutive days of i.v. administration, the results showed that the group treated with Angiopep-PEG-PE/AmB achieved the greatest treatment efficacy, which reached the highest AmB level in brain, reduced the brain fungal burden significantly, decreased histopathological severity and prolonged the median survival time. The increased treatment efficacy could be attributed to the brain-targeting delivery system promoted AmB crossing the BBB and penetrating into the brain to reach the therapeutic concentration. The underlying mechanism was also explored in this work. Therefore, the brain-targeting delivery system could have potential and promising implications for treatment of intracerebral fungal infection.

Factors affecting the pharmacokinetics and pharmacodynamics of liposomal drugs

Various attempts to increase the therapeutic index of the drug while minimizing side effects have been made in drug delivery systems. Among several promising strategies, liposomes represent an advanced technology to target active molecules to the site of action. Rapid clearance of circulating liposomal drugs administered intravenously has been a critical issue because circulation time in the blood affects drug exposure at the target site. The clinical use of liposomal drugs is complicated by large intra- and interindividual variability in their pharmacokinetics (PK) and pharmacodynamics (PD). Thus, it is important to understand the factors affecting the PK/PD of the liposomal formulation of drugs and to elucidate the mechanisms underlying the variability in the PK/PD of liposomal drugs. In this review article, we describe the characteristics of liposome formulations and discuss the effects of various factors, including liposome-associated factors, host-associated factors, and treatment on the PK/PD of liposomal agents.

Clinical development of liposome-based drugs: formulation, characterization, and therapeutic efficacy

Research on liposome formulations has progressed from that on conventional vesicles to new generation liposomes, such as cationic liposomes, temperature sensitive liposomes, and virosomes, by modulating the formulation techniques and lipid composition. Many research papers focus on the correlation of blood circulation time and drug accumulation in target tissues with physicochemical properties of liposomal formulations, including particle size, membrane lamellarity, surface charge, permeability, encapsulation volume, shelf time, and release rate. This review is mainly to compare the therapeutic effect of current clinically approved liposome-based drugs with free drugs, and to also determine the clinical effect via liposomal variations in lipid composition. Furthermore, the major preclinical and clinical data related to the principal liposomal formulations are also summarized.

Treatment of early and established Cryptococcus neoformans infection with radiolabeled antibodies in immunocompetent mice

We investigated the utility of radioimmunotherapy (RIT) in early and established cryptococcal infection in immunocompetent mice. RIT with (213)Bi-18B7 antibody completely eliminated fungus from mouse lungs and brains for early infection, while (188)Re-18B7 significantly reduced CFU in the lungs or both lungs and brains during early and established infection, respectively. The results point to the independence of RIT of the immune status of the host, which is encouraging for translation of this strategy into the clinic.

Clinical presentation, diagnosis and management of Cryptococcus gattii cases: Lessons learned from British Columbia

The environmental fungus Cryptococcus gattii emerged on Vancouver Island, British Columbia (BC), in 1999. By the end of 2006, it led to 176 cases and eight deaths - one of the highest burdens of C gattii disease worldwide. The present paper describes three cases, and the BC experience in the diagnosis and management of this infection. All three cases presented with pulmonary findings, including cryptococcomas and infiltrates. One also presented with brain cryptococcomas. Cases were diagnosed by chest and brain imaging, and laboratory evidence including serum or cerebrospinal fluid cryptococcal antigen detection and culture of respiratory or cerebrospinal fluid specimens. Genotyping of fungal isolates confirmed infection with C gattii VGIIa. Pulmonary cases were treated with fluconazole. One patient with central nervous system disease was treated with amphotericin B followed by fluconazole. Although this infection remains rare, clinicians should be aware of it in patients with a compatible clinical presentation who are either living in or returning from a trip to BC.

Cryptococcus neoformans as a Model for Radioimmunotherapy of Infections

There is an obvious and urgent need for novel approaches to treat infectious diseases. The use of monoclonal antibodies in therapy of infectious diseases is now experiencing renewed interest. During the last 5 years radioimmunotherapy (RIT), a modality previously developed only for cancer treatment, has been successfully adapted for the treatment of experimental fungal, bacterial, and viral infections. As our model organism for studying the efficacy, mechanisms, potential toxicity, and radioresistance to RIT, as well as for comparison of RIT with the existing antimicrobial therapies we have chosen the encapsulated yeast Cryptococcus neoformans (CN). The success of RIT approach in laboratory studies provides encouragement for feasibility of therapeutically targeting microbes with labeled antibodies. In addition, the creation of “panantibodies” for RIT which would recognize antigens shared by the whole class of pathogens such as fungi, for example, would facilitate the introduction of RIT into the clinic.

Therapeutic and toxicologic studies in a murine model of invasive pulmonary aspergillosis

Invasive pulmonary aspergillosis remains problematic in immunocompromised patient populations. We studied potential therapeutic options in a murine model of pulmonary aspergillosis in triamcinolone-suppressed DBA/2 mice infected intranasally with conidia from Aspergillus fumigatus. Mice were treated with liposomal-amphotericin B (AmBi; AmBisome), lipid-complexed amphotericin B (ABLC; Abelcet), voriconazole (VCZ), micafungin (MICA), caspofungin (CAS) or deoxycholate amphotericin B (AMBd) given alone or in combination. Monotherapy with AmBi, ABLC, AMBd, CAS or MICA had activity in prolonging survival; however, only AMBd or CAS reduced fungal burden in the lungs and kidneys. Combinations of AmBi plus CAS or MICA prolonged survival, but were not better than monotherapy. VCZ was ineffective and AMBd plus CAS showed a possible antagonism. AmBi or ABLC at higher dosages, or loading-doses of AmBi resulted in reduced survival. Histopathology showed increased incidence of serious renal and mild hepatic toxicity in triamcinolone-treated mice given an amphotericin B regimen compared to no or only triamcinolone (minimal renal changes occurred with CAS or VCZ with or without triamcinolone); suggestive of combined toxicity of triamcinolone and the amphotericin B in AmBi or ABLC. Infected treated mice showed progressive pulmonary disease including abscesses, angioinvasion and abundant intralesional fungi. High loading-doses of AmBi were associated with nephrosis and damage to other tissues. No monotherapy or combination regimen showed superiority for the treatment of pulmonary aspergillosis in corticosteroid suppressed mice and the potential for combined drug toxicity was enhanced in these mice. High dosages of lipid-formulated amphotericin B also proved unsatisfactory. Additional studies are needed to evaluate improved treatment.

Radioimmunotherapy is more effective than antifungal treatment in experimental cryptococcal infection

Radioimmunotherapy (RIT) prolongs the survival of mice infected with Cryptococcus neoformans. To compare the efficacy of RIT with that of amphotericin B, we infected AJ/Cr mice intravenously with either nonmelanized or melanized C. neoformans cells. Infected mice were either left untreated or treated 24 h after infection with (213)Bi-18B7 antibody, amphotericin B, or both. Melanization before infection did not increase resistance of C. neoformans to RIT in vivo. (213)Bi-18B7 treatment almost completely eliminated colony-forming units from the lung and brain, whereas amphotericin B did not decrease the number of colony-forming units. We conclude that RIT is more effective than amphotericin B against systemic infection with C. neoformans.

Cerebral aspergillosis: tissue penetration is the key

Cerebral aspergillosis is increasingly recognized in severely immunocompromised patients and, until recently, this type of fungal infection was associated with a mortality approaching 100%. The central nervous system is a protected environment and penetration of drugs across the blood-brain barrier is mainly limited by their molecular size and physicochemical properties, as well as drug interaction with transporter systems (e.g., P-glycoprotein) at the blood-brain barrier. Most antifungal agents are large molecules (>700 Da), which makes sufficient penetration into the central nervous system unlikely. In fact, the available data indicate low levels of most antifungal agents in cerebrospinal fluid and brain tissue, except for fluconazole and voriconazole. Concentrations of voriconazole exceeding inhibitory concentrations for Aspergillus species were found repeatedly in cerebrospinal fluid and brain tissue, including brain abscess material. A recent retrospective study confirmed that voriconazole treatment resulted in improved response and survival rates in patients with cerebral aspergillosis. Data from animal models, which explored escalated doses or combinations of antifungal agents in experimental neuroaspergillosis, suggest that selected combination or dose-escalated therapies might further improve the still unsatisfactory prognosis in this particular type of Aspergillus infection.

Efficacy of alternative dosing regimens of poly-aggregated amphotericin B

A new poly-aggregated form of amphotericin B was formulated as a non-microencapsulated form (P-AMB) or incorporated in albumin microspheres (MP-AMB) and compared with the conventional amphotericin B formulation (D-AMB). Mice were infected with Candida albicans and treated with two different intermittent dose regimens of the different amphotericin B formulations. Efficacy and toxicity were studied by the determination of survival rate, kidney colony-forming units counts, biochemical parameters and amphotericin B concentrations in plasma and organs. All the treatments significantly (P<0.05) increased the survival rate in relation to the untreated group, although non-statistically significant differences (P>0.05) were found between formulations and dosing regimens. All the treatments produced kidney toxicity, expressed by high urea levels. Kidney toxicity was especially significant for mice treated with the D-AMB formulation where unilateral kidney atrophy was observed in most of the mice, whereas most of the mice treated with P-AMB conserved both kidneys with a normal size and appearance. At 45 days post infection, variable distribution of amphotericin B in the body was obtained depending on the amphotericin B formulation. In conclusion, non-daily dosing regimens of P-AMB, which is less toxic than D-AMB, could be used as an alternative to the conventional D-AMB formulation to treat experimental candidiasis.

Delivery systems to increase the selectivity of antibiotics in phagocytic cells

Many infectious diseases are caused by facultative organisms that are able to survive in phagocytic cells. The intracellular location of these microorganisms protects them from the host defence systems and from some antibiotics with poor penetration into phagocytic cells. One strategy used to improve the penetration of antibiotics into phagocytic cells is the use of carrier systems that deliver these drugs directly to the target cell. Delivery systems such as liposomes, micro/nanoparticles, lipid systems, conjugates, and biological carriers such as erythrocyte ghosts may contribute to increasing the therapeutic efficacy of antibiotics and antifungal agents in the treatment of infections caused by intracellular microorganisms. The main objective of this review is to analyze recent advances and current perspectives in the use of antibiotic delivery systems in the treatment of intracellular infections such as mycobacterial infections, brucellosis, salmonellosis, listeriosis, fungal infections, visceral leishmaniasis, and HIV.

Comparison of the physicochemical, antifungal, and toxic properties of two liposomal amphotericin B products

Small unilamellar amphotericin B liposomes can reduce the toxicity of amphotericin B. In this study, we compared the physical, antifungal, pharmocokinetic, and toxic properties of two liposomal amphotericin B products, AmBisome and Anfogen, that have the same chemical composition but are manufactured differently. In vitro tests included determinations of the MICs and the concentrations causing the release of 50% of the intracellular potassium from red blood cells (K50 values) to assess toxicity. The 50% lethal dose (LD50) was evaluated by using uninfected C57BL/6 mice and single intravenous (i.v.) doses of 1 to 100 mg/kg of body weight. Multiple i.v. dosing over 18 days was performed with 0.5, 1.0, or 5.0 mg of Anfogen/kg or 1.0, 5.0, or 25 mg of AmBisome/kg to evaluate chronic toxicity. DBA/2 mice were infected intranasally with 2.5 x 10(6) Aspergillus fumigatus conidia, treated for 3 or 4 days with 3.0, 5.0, or 7.5 mg of Anfogen/kg or 3, 5, 7.5, or 15 mg of AmBisome/kg, and evaluated to assess the toxicity of the drugs to the kidneys (by measurement of blood urea nitrogen and creatinine levels and histopathology) and the drug efficacy. The median particle size was 77.8 nm for AmBisome and 111.5 nm for Anfogen. In vitro K(50) values were significantly lower for Anfogen (0.9 mug/ml) than for AmBisome (20 microg/ml), and the LD50 of AmBisome was >100 mg/kg, versus 10 mg of Anfogen/kg. There was significant renal tubular necrosis in uninfected and infected mice given Anfogen but no tubular necrosis in AmBisome-treated mice. AmBisome at 7.5 or 15 mg/kg was also more efficacious than 7.5 mg of Anfogen/kg for the treatment of pulmonary aspergillosis, based on survival and weight loss data and numbers of CFU per gram of lung. In conclusion, the efficacy and toxicity of these two liposomal amphotericin B products were significantly different, and thus, the products were not comparable.

Invasive aspergillosis in children with hematologic malignancies

The respiratory tract is the most common system affected by aspergillosis in children with hematologic malignancies. However, Aspergillus spp. tend to invade blood vessels, resulting in systemic dissemination to multiple organs including, but not limited to, the brain, bones, liver, kidneys, and skin. Because early diagnosis and treatment are critical to the patient's outcome, a high index of suspicion should be maintained in children with hematologic malignancies who are neutropenic and have prolonged fever that is unresponsive to systemic antibacterials. Several diagnostic modalities should be used simultaneously in order to establish the diagnosis in an expeditious manner. Detailed radiographic evaluations with plain radiographs, and CT scans of the chest, sinuses, brain, and other organs should be performed as soon as clinical suspicion is raised. Detection of circulating antigens, such as galactomannan and 1,3-beta-glucan, and polymerase chain reaction appear promising in aiding in the diagnosis. A definitive diagnosis requires both a positive culture from a sterile site and evidence of tissue damage demonstrated by imaging studies or microscopic evaluations of sites of infection. Because the mortality rate is very high, empiric systemic antifungal therapy with amphotericin B, or one of its lipid formulations, should be initiated while laboratory investigations to substantiate or refute the diagnosis are continued. Surgical intervention is associated with a high mortality rate but may be of benefit in children with localized disease.

Pharmacocinétique des antifongiques en fonction du terrain

Antifungal drugs for treating systemic mycoses are flucytosine, amphotéricin B, azoles and caspofungin. Their pharmacokinetics and pharmacodynamics are reviewed in order to determine the optimal modalities of their administration and the best dosing regimen for several populations: neonates, infants, patients with renal or liver disease, patients with hemodialysis or hemofiltration.

Population pharmacokinetics of liposomal amphotericin B in pediatric patients with malignant diseases

A population pharmacokinetic model of liposomal amphotericin B (L-AmB) in pediatric patients with malignant diseases was developed and evaluated. Blood samples were collected from 39 pediatric oncology patients who received multiple doses of L-AmB with a dose range from 0.8 to 5.9 mg/kg of body weight/day. The patient cohort had an average age of 7 years (range, 0.2 to 17 years) and weighed an average of 28.8 +/- 19.8 kg. Population pharmacokinetic analyses were performed with NONMEM software. Pharmacokinetic parameters, interindividual variability (IIV), between-occasion variability (BOV), and intraindividual variability were estimated. The influence of patient characteristics on the pharmacokinetics of L-AmB was explored. The final population pharmacokinetic model was evaluated by using a bootstrap sampling technique. The L-AmB plasma concentration-time data was described by a two-compartment pharmacokinetic model with zero-order input and first-order elimination. The population mean estimates of clearance (CL) and volume of distribution in the central compartment (V1) were 0.44 liters/h and 3.12 liters, respectively, and exhibited IIV (CL, 10%) and significant BOV (CL, 46% and V1, 56%). The covariate models were CL (liters/h) = 0.44 . e(0.0152.(WT-21)) and V1 (liters) = 3.12.e(0.0241.(WT-21)), where WT is the patient's body weight (kg) centered on the study population cohort median of 21 kg. Model evaluation by the bootstrap procedure indicated that the full pharmacokinetic model was robust and parameter estimates were accurate. In conclusion, the pharmacokinetics of L-AmB in pediatric oncology patients were adequately described by the developed population model. The model has been evaluated and can be used in the design of rational dosing strategies for L-AmB antifungal therapy in this special population.

Pharmacokinetic-pharmacodynamic comparison of amphotericin B (AMB) and two lipid-associated AMB preparations, liposomal AMB and AMB lipid complex, in murine candidiasis models

It is generally accepted that the lipid formulations of amphotericin B (AMB) are not as potent as conventional AMB on a milligram-per-kilogram basis. We used a neutropenic murine disseminated candidiasis model to compare the in vivo potencies of AMB, liposomal AMB (L-AMB), and AMB lipid complex (ABLC) pharmacodynamically. The pharmacokinetics of the antifungals were examined in serum and in three organs commonly seeded in disseminated candidiasis (kidneys, liver, and lung). Both single-dose time-kill studies and multiple-dosing-regimen studies were used with each of the compounds. Determinations of the numbers of CFU in the kidneys were performed following the administration of three escalating single doses of the polyenes at various times over 48 h. The areas under the time-kill curves (AUTKs) for each dose level of the drugs were compared by analysis of variance (ANOVA). In the multiple-dosing-regimen studies with five Candida isolates, AMB, L-AMB, and ABLC were administered daily for 72 h. The organism burdens in the mouse kidneys were similarly used as the treatment end point. Additional multiple regimen-dosing-studies were performed with a single Candida albicans isolate, and the microbiologic outcomes in four internal organs (kidneys, liver, spleen, and lung) were examined at the end of therapy (48 h). The relationship between the dose and the drug exposure expressed by the pharmacokinetics of the dosing regimens in serum and organ tissue were analyzed by using a maximum-effect model. ANOVA was used to compare the drug exposures necessary to achieve the 25% effective dose (ED25), ED50, ED75, and 1 log10 killing. Comparison of AUTKs suggested that AMB was 4.3- to 5.9-fold more potent than either ABLC or L-AMB. The time-kill curves for both lipid formulations were very similar. In the multiple-dosing-regimen studies, AMB was 5.0- to 8.0-fold more potent than each of the lipid formulations against five Candida isolates in the kidneys. Similar differences in potency (5.1- to 7.2-fold) were observed in the other end organs. The difference in pharmacokinetics in serum accounted for much of the difference in potency between AMB and ABLC (ratio of serum ABLC area under the curve of effective doses to serum AMB area under the curve of effective doses, 1.2). The differences in the kinetics in the various end organs between AMB and L-AMB were better at explaining the disparate potencies at these infection sites (ratio of organ L-AMB area under the curve of effective doses to organ AMB area under the curve of effective doses, 1.1).

Liposomal amphotericin B: clinical experience and perspectives

While amphotericin B deoxycholate (Fungizone, Apothecon Pharmaceuticals) has been considered by many to be the gold standard for the treatment for numerous invasive fungal infections for over 45 years, toxicities associated with its use often necessitate treatment modification or discontinuation. Lipid-based formulations, including liposomal amphotericin B (AmBisome, Fujisawa Healthcare, Inc.), were developed to decrease many of these toxicities while retaining broad antifungal spectrum and potency of amphotericin B. In clinical trials, liposomal amphotericin B has demonstrated efficacy comparable to that of amphotericin B deoxycholate while reducing the incidence of treatment-related nephrotoxicity, electrolyte-wasting, and infusion-related reactions. In addition, recent clinical trials have also compared liposomal amphotericin B with other antifungal classes. Acquisition costs of liposomal amphotericin B are substantially higher than those of amphotericin B deoxycholate and other antifungals. While pharmacoeconomic analyses consider outcomes and other treatment-related costs, they have yet to clearly demonstrate the cost-effectiveness of liposomal amphotericin B when compared with amphotericin B deoxycholate or other antifungal agents. This review will focus primarily on recent liposomal amphotericin B experience and attempt to put its use into perspective considering other available antifungal agents.

Experimental systemic infection withCryptococcus neoformansvar.grubiiandCryptococcusgattiiin normal and immunodeficient mice

Cryptococcus neoformans (Cn) var. grubii or Cryptococcus neoformans var. neoformans infection is usually associated with immunocompromised hosts, whereas Cryptococcusgattii more frequently causes disease in immunocompetent hosts. We examined the effects of immunodeficiency and glucocorticoid-induced immunosuppression on systemic murine infection induced by i.v. inoculation with these pathogens. SCID and immunocompetent BALB/c and C57BL/6 mice were infected with <or=107 yeast of Cn var. grubii or C. gattii; immunosuppressed BALB/c mice were infected with <or=106 yeast. Mortality was inoculum size-dependent in each model system, for both organisms. Following infection with 106 CFU of either Cn var. grubii or C. gattii immunocompetent BALB/c mice survived longer than immunosuppressed mice (P<0.0001 in both cases); no differences were found using lower inocula. SCID mice infected with Cn var. grubii or C. gattii died sooner than BALB/c mice (P<0.0013, all comparisons). Unexpectedly, BALB/c mice infected with C. gattii developed external lesions. Immunocompetent mice developed rectal prolapse more frequently whereas immunosuppressed mice developed more frequent skin lesions, predominantly on the tail. The fungal burden was especially high in rectum, skin and lung tissues. Histologic examination showed extensive infection of the rectum and skin and pneumonitis. Determination of CFU from various organs of immunocompetent BALB/c mice infected i.v. with 105 CFU of C. gattii or Cn var. grubii showed significant temporal increase of burdens of Cn var. grubii in brain and liver (P<0.003); other organs showed decreasing fungal burden. C.gattii was recovered only from liver and lungs, no CFU were detected in the other organs. As opposed to epidemiologic observations, our results demonstrate no predilection by C. gattii for infection of immunocompetent over immunosuppressed hosts; immunosuppression increased the risk of severe cryptococcosis by both varieties, especially at high inocula. This is the first report of C. gattii inducing experimental cutaneous and intestinal mucosal infection; Cn var. grubii did not affect these tissues, indicating differences in tissue tropism of these pathogens.

Optimizing efficacy of amphotericin B through nanomodification

Fungal infections and leishmaniasis are an important cause of morbidity and mortality in immunocompromised patients. The macrolide polyene antibiotic amphotericin B (AmB) has long been recognized as a powerful fungicidal and leishmanicidal drug. A conventional intravenous dosage form of AmB, AmB- deoxycholate (Fungizone or D-AmB), is the most effective clinically available for treating fungal and parasitic (leishmaniasis) infections. However, the clinical efficacy of AmB is limited by its adverse effects mainly nephrotoxicity. Efforts to lower the toxicity are based on synthesis of AmB analogues such as AmB esters or preparation of AmB-lipid associations in the forms of liposomal AmB (L-AmB or AmBisome), AmB lipid complex (Abelcet or ABLC), AmB colloidal dispersion (Amphocil or ABCD), and intralipid AmB. These newer formulations are substantially more expensive, but allow patients to receive higher doses for longer periods of time with decreased renal toxicity than conventional AmB. Modifications of liposomal surface in order to avoid RES uptake, thus increased targetability has been attempted. Emulsomes and other nanoparticles are special carrier systems for intracellular localization in macrophage rich organs like liver and spleen. Injectable nano-carriers have important potential applications as in site-specific drug delivery.

Successful Use of Amphotericin B Lipid Complex in the Treatment of Cryptococcosis

The efficacy and renal safety of amphotericin B lipid complex (ABLC) injection were assessed in 106 patients with cryptococcal infection. Eighty-three patients (78%) had a central nervous system (CNS) infection. Of these patients, 20 initiated azole therapy concomitantly with ABLC therapy, and 7 had received prior azole therapy, which continued during administration of ABLC. Clinical response (cured or improved) was achieved in 67 (66%) of 101 patients whose results could be evaluated. Response rates were 65% (51/78) for patients with a CNS infection and 70% (16/23) for patients without a CNS infection. The response rate for patients with HIV infection was 58% (30/52). Response rates were 56% (19/34) for patients who were refractory to prior antifungal therapy, 65% (11/17) for patients who were intolerant of prior antifungal therapy, 60% (3/5) for patients with underlying renal disease who received prior antifungal therapy, 76% (25/33) for patients with underlying renal disease who did not receive prior antifungal therapy, and 73% (8/11) for patients with no renal disease who did not receive prior antifungal therapy. A mean serum creatinine level decrease of 0.02 mg/dL occurred. ABLC was an effective treatment for cryptococcal infection in immunocompromised patients.

A case of chromoblastomycosis with an unusual clinical manifestation caused by Phialophora verrucosa on an unexposed area: treatment with a combination of amphotericin B and 5-flucytosine

Chromoblastomycosis is a cutaneous and subcutaneous mycotic disease caused by the dematiaceous (black) fungi. Five species of fungi are known generally to be the cause: Fonsecaea pedrosoi, Phialophora verrucosa, Cladosporium carrionii, F. compacta and Rhinocladiella cerphilum. In infected tissue they can appear as pigmented sclerotic bodies, commonly called 'copper pennies', which are pathognomonic of chromoblastomycosis. The infection usually occurs through traumatic skin inoculation, with the majority of lesions occurring on the feet and legs of outdoor workers. We report a patient in whom the lesions had begun on the right breast, which is an unexposed area, without a history of trauma. A uniform, reliable treatment does not exist but our patient was mycologically cured with the use of amphotericin B and the subsequent combination of 5-flucytosine and itraconazole.

Treatment of invasive Aspergillosis in children with hematologic malignancies

The respiratory tract is the most common organ involved with Aspergillosis in children with hematologic malignancies. Also Aspergillus species tend to invade blood vessels resulting in systemic dissemination to multiple organs. Early diagnosis and treatment are pivotal to the patient's outcome. A high index of suspicion should be maintained in children who have profound neutropenia and present with prolonged fever that is unresponsive to systemic antibiotics. Several diagnostic modalities should be used simultaneously in order to confirm the diagnosis in an expedited manner. Combination and sequential antifungal therapy have been shown to be of added benefit. Surgical intervention is associated with a high mortality rate, but may be indicated in children with a localized disease. In this article the authors review the epidemiology, microbiology, pathology, and clinical manifestations of invasive aspergillosis in children with hematologic malignancies. Current diagnostic approach, medical, and surgical treatment options are discussed.

Efficacies of Amphotericin B (AMB) Lipid Complex, AMB Colloidal Dispersion, Liposomal AMB, and Conventional AMB in Treatment of Murine Coccidioidomycosis

The therapeutic efficacy of three lipid formulations of amphotericin B was compared with that of conventional amphotericin B in treatment of murine coccidioidomycosis. All treatments prolonged survival compared with the no-treatment group ( P < 0.0001). Although conventional amphotericin B was more active than lipid formulations on reducing quantitative fungal load on a milligram-per-kilogram basis ( P < 0.003 to 0.0002), the lipid preparations could be administered at higher doses, sterilizing liver and spleen tissues. The efficacies of the lipid preparations were similar in this murine model of coccidioidomycosis.

Comparative efficacies of four amphotericin B formulations--Fungizone, amphotec (Amphocil), AmBisome, and Abelcet--against systemic murine aspergillosis

We compared various amphotericin B formulations (no treatment or 0.8 mg of Fungizone [conventional deoxycholate amphotericin B] per kg of body weight, or 0.8, 4, or 8 mg of Amphocil, AmBisome, or Abelcet per kg of body weight) for treatment of systemic murine aspergillosis. In two studies, all formulations prolonged survival, with the results for AmBisome nearly equivalent to those for Fungizone; Amphocil and Abelcet were less effective or equivalent depending on the severity of infection. No survivors were cured in both kidneys and brain, but each formulation showed efficacy, especially in the kidneys. Although higher doses could be given, no lipid-based formulation showed consistent superiority over Fungizone or over each other.

Guidelines for the use of antifungal agents in the treatment of invasiveCandidaand mould infections

ABSTRACT Treatment of invasive fungal infections is increasingly complex. Amphotericin B deoxycholate has long been the mainstay of treatment. However, there has been increasing recognition of both the propensity for nephro-toxicity in haematology, transplant and intensive care patients as well as its adverse impact on morbidity and mortality. This has coincided with the availabilty of newer, and in certain settings, more effective antifungal agents. Although the newer agents clearly cause less nephrotoxicity than amphotericin B, drug interactions, hepatic effects and unique side-effects need to be considered. The spectrum of the newer triazoles and echinocandins varies, highlighting the importance of accurate identification of the causative organism where possible. Consensus Australian guidelines have been developed to assist clinicians with treatment choices by reviewing the current evidence for the efficacy, the toxicity and the cost of these agents.

Newer antifungal agents

Invasive fungal infections have evolved into significant causes of morbidity and mortality in premature infants, immunocompromised children, and patients receiving immunosuppressive agents. Since the discovery in 1955, amphotericin B has been the cornerstone of antifungal treatment. The past 10 years, however, have witnessed a major expansion in the antifungal armamentarium through the development of less toxic formulations of Amphotericin B, the introduction of improved triazoles, and the advent of the echinocandin lipopeptides. In this article we discuss the Lipid-based amphotericin B, Voriconazole (a new azole), and Caspofungin (an echinocandin).