Effective Blood Concentration of Micafungin for Pulmonary Aspergillosis

We previously reported that a 150 mg or higher daily dose is necessary for treatment of pulmonary aspergillosis with micafungin (MCFG) alone in patients with blood diseases. Since a delay in the treatment of pulmonary aspergillosis has a major influence on patient survival, clarification of the effective blood concentration of MCFG enables rapid treatment. Establishment of an appropriate dose is also useful for reducing the risk of adverse effects, such as MCFG-induced impairment of liver function. Aiming for the rapid and safe treatment of pulmonary aspergillosis, we established new clinical diagnostic criteria of mycosis and MCFG therapeutic effect judgment criteria, and investigated the effective blood concentration of MCFG for mycosis. The blood trough level of MCFG in patients with blood diseases at each clinical improvement rating of pulmonary aspergillosis was 5.23+/-2.44 microg/ml in markedly improved cases, 4.08+/-2.63 microg/ml in improved cases, and 3.45+/-1.63 microg/ml in successfully prevented cases, showing no significant difference among the 3 groups. Based on this finding, it is advisable to target a 5 microg/ml or higher blood trough level of MCFG in establishing the dose for aspergillosis in patients with blood diseases.

Intratracheal gene transfer of tissue factor pathway inhibitor attenuates pulmonary fibrosis

Activation of the coagulation system and increased expression of tissue factor (TF) in pulmonary fibrosis associated with acute and chronic lung injury have been previously documented. In the present study, we evaluated the effect of TF inhibition with intratracheal gene transfer of tissue factor pathway inhibitor (TFPI), a potent and highly specific endogenous inhibitor of TF-dependent coagulation activation, in a rat model of bleomycin-induced lung fibrosis. Significant lung fibrotic changes as assessed by histologic findings and hydroxyproline content, and increased procoagulant activity and thrombin generation in bronchoalveolar lavage fluid were detected in rats after intratracheal injection of bleomycin. Intratracheal administration of an adenovirus vector expressing TFPI significantly decreased bleomycin-induced procoagulant and thrombin generation resulting in a strong inhibition of pulmonary fibrosis. TFPI-overexpression in the lung was associated with a significant reduction in gene expression of the connective tissue growth factor, a potent profibrotic growth factor. This is the first report showing that direct inhibition of TF-mediated coagulation activation abrogates bleomycin-induced pulmonary fibrosis.

International, open-label, noncomparative, clinical trial of micafungin alone and in combination for treatment of newly diagnosed and refractory candidemia

Candida spp. are the fourth leading cause of bloodstream infections, and non-albicans species are increasing in importance. Micafungin is a new echinocandin antifungal agent with excellent in vitro activity against Candida spp. Pediatric, neonatal, and adult patients with new or refractory candidemia were enrolled into this open-label, noncomparative, international study. The initial dose of micafungin was 50 mg/d (1 mg/kg for patients <40 kg) for infections due to C. albicans and 100 mg/d (2 mg/kg for patients <40 kg) for infections due to other species. Dose escalation was allowed. Maximum length of therapy was 42 days. A total of 126 patients were evaluable (received at least five doses of micafungin). Success (complete or partial response) was seen in 83.3% patients overall. Success rates for treatment of infections caused by the most common Candida spp. were as follows: C. albicans 85.1%, C. glabrata 93.8%, C. parapsilosis 86.4%, and C. tropicalis 83.3%. Serious adverse events related to micafungin were uncommon. Micafungin shows promise as a safe and effective agent for the treatment of newly diagnosed and refractory cases of candidemia. Large-scale, randomized, controlled trials are warranted.

Electron microscopic findings for micafungin-treated experimental pulmonary aspergillosis in mice

We performed a scanning and transmission electron microscopic study on the efficacy of micafungin (MCFG) to understand what kind of damage MCFG causes to Aspergillus and to confirm its previously reported in vitro killing activity against Aspergillus in a mouse model of pulmonary aspergillosis. Aspergillus hyphae in MCFG-treated mice displayed hyphal burst, evidenced as either flattened or atrophied appearance and leakage of cellular contents after collapse of the cell wall. Thus, MCFG can induce the destruction of Aspergillus hyphae at the focus of infection. The results of the present study indicate that MCFG improves pulmonary aspergillosis due to lethal damage to Aspergillus hyphae. This action can effectively reduce the invasive ability of Aspergillus even though MCFG does not sterilize the fungal burden.

TLR2 agonist ameliorates established allergic airway inflammation by promoting Th1 response and not via regulatory T cells

TLRs are primary sensors of both innate and adaptive immune systems, where they play a pivotal role in the response directed against structurally conserved components of pathogens. Synthetic bacterial lipopeptide Pam3CSK4 is a TLR2 agonist capable of modulating Th1 and Th2 responses. This study examines the therapeutic effect of Pam3CSK4 in established airway inflammation in a murine model of asthma. In mice previously sensitized and challenged with OVA, Pam3CSK4 given i.p. markedly reduced the total inflammatory cell infiltrate and eosinophilia in bronchoalveolar lavage fluid. Pam3CSK4 therapy was associated with a reduction in OVA-induced IL-4 and IL-5 secretion from thoracic lymph node culture, airways inflammation, bronchial hyperresponsiveness, and serum levels of IgE. Pam3CSK4 therapy was also associated with an increase in OVA-induced IFN-gamma, IL-12, and IL-10 production. However, the anti-inflammatory effect of Pam3CSK4 was independent of IL-10 or TGF-beta, but was critically dependent on IL-12, the production of which by dendritic cells was enhanced by Pam3CSK4 in vitro. Our results provide direct evidence that Pam3CSK4 could represent a novel therapeutic agent in allergic airways disease.

[Successful treatment with micafungin in a case of candidemia associated with pneumonia]

A 63-year-old woman was admitted to our hospital with fever and cough. Candidemia was diagnosed by blood culture and culture of IVH catheter. Although, the patient was treated with fluconazole, clinical symptoms and chest radiographic findings worsened. After micafungin was replaced with fluconazole, her symptoms, chest radiographic findings improved and stabilized. It is suggested that micafungin is useful for the treatment of candidemia associated with Candida parapsilosis.

Successful Topical Application of a New Antifungal Agent, Micafungin, in the Treatment of Refractory Fungal Corneal Ulcers

PURPOSE

To report the efficacy of topical application of a new antifungal agent, micafungin (MCFG), in the treatment of yeast-related corneal ulcers.

DESIGN

Noncomparative interventional case reports.

PARTICIPANTS

Three patients with yeast-related corneal ulcer after keratoplasty recalcitrant to conventional antifungal treatment for 4 weeks were recruited in this study.

METHODS

Topical 0.1% antifungal MCFG eye drops were applied in 3 patients with yeast-related corneal ulcer every hour while awake until epithelialization. After epithelialization, the frequency of eye drops was reduced to 5 times a day. MCFG eye drops were discontinued 1 month after the disappearance of stromal infiltration in each case. The patients underwent best corrected visual acuity (BCVA) measurements, slit-lamp examination, fluorescein-dye staining, and anterior segment photography. Corneal scrapings and cultures of surgical materials were also performed.

MAIN OUTCOME MEASURES

Changes in ulcer size, stromal infiltration, fluorescein dye staining, and BCVA were looked for.

RESULTS

All corneal ulcers epithelialized within 14 days after commencement of application of 0.1% MCFG eye drops. Yeasts were detected from corneal smears in all eyes. Two cases revealed positive culture isolates for Candida albicans and Candida parapsilosis. No recurrence of fungal keratitis was observed in any of the cases throughout the follow-up periods.

CONCLUSION

Topical 0.1% MCFG eye drops seem to be an effective and a promising option in the treatment of refractory yeast-related corneal ulcers.

Antifungal treatment in pediatric patients

Invasive fungal infections have increased in frequency and severity over the past two decades as a result of an increasing number of immunocompromised patients. This new age of opportunistic fungal infections extends to pediatric patients. The last decade has seen the development of several new antifungal agents for the treatment of these infections. However, there is a paucity of data on the treatment of invasive fungal infections in children. This review provides a brief overview of the current state of antifungal therapy for children, discussing the important antifungal classes and the differences in mechanisms of action and resistance, pharmacology, and efficacy and safety data in pediatric patients outside the neonatal period.

[A case of chronic mucocutaneous candidasis cured with micafungin]

Chronic mucocutaneous candidasis (CMC) is a chronic intractable infection of skin, nails, and mucous membrane with Candida. Until very recently, the main stay of therapy had been the use of transfer factor or antifungal azole derivatives. Although they show definite benefits, the effects are temporal and recurrences are inevitable. Furthermore, the prolonged use of antifungals will sometimes induce resistant strains, making the treatment more difficult. Recently we experienced a case of CMC caused by resistant Candida spp. and treated it successfully with a new antifungal agent, micafungin (MCFG). The patient is a 37-year-old woman. She was eight month, her tongue was covered with a white coat. Two months later, intractable cutaneous eruptions appeared on the head and back and the diagnosis of CMC was made. Since then she has been treated on multiple occasions with transfer factor, recombinant IL-2, ketoconazole or clotrimazole. She was referred to us because of esophageal candidiasis. On admission, oral and esophageal mucous membranes were thickly coated with white pseudomembranes. The titer of Candida antigen test was less than twice ; plasma beta-D-gulcan was 20.14 pg/mL ; and CD4 was 376/microL. A few Candida albicans and (1+) Candida glabrata were cultured from oral swab. Both species were resistant to itraconazole but sensitive to MCFG and amphotericin B (MIC: < 0.03microg/ml for both). A drip infusion of MCFG (75mg/day) was started and three days later the oral lesions disappeared. At the end of a 2-week course of i. v. MCFG, the interior of the esophagus was clear. No recurrence was noted in one month. Less toxic than amphotericin B, MCFG will be a drug of choice in patients infected with azole-resistant fungi. To avoid the abuse of MCFG and the development of the resistant strains, the susceptibility test is recommended in every case of systemic candidiasis.

Therapeutic intervention and targets for sepsis

Sepsis syndrome, a systemic response to infection, can beget devastating outcomes even in previously normal individuals. Recent research in septic patients has led to the discovery that early goal-directed resuscitation guided by continuous monitoring of mixed venous hemoglobin saturation, along with moderate doses of corticosteroids, can reduce mortality. An improved understanding of the complex interaction between the inflammatory and coagulant systems in sepsis pathophysiology has resulted in novel treatments, such as recombinant human activated protein C, which improves survival in patients with severe sepsis and a high risk of death. However, despite an increased understanding of the complex pathophysiology of this syndrome and the discovery of new, effective treatments, severe sepsis still results in significant morbidity and mortality. Consequently, investigations continue into additional therapeutic agents directed against novel targets. Following a review of recent advances in sepsis treatment, we briefly discuss a few of the new, promising therapeutic strategies currently being investigated.

Tissue Factor Pathway Inhibitor and Anitithrombin Trial Results

The endogenous plasma anticoagulant proteins tissue factor pathway inhibitor (TFPI) and antithrombin (AT) have both been extensively studied in large, multinational phase III clinical trials in patients with severe sepsis. The TFPI and AT trials failed to result in significant reductions in the 28-day, all-cause mortality rates in their respective study populations. However, there appear to be definable patient populations within each study that may have benefited from TFPI or AT. Drug-drug interactions and dosing issues were observed in both trials. The similarities and differences of each anticoagulant and the lessons learned from the recent phase III clinical trials are examined in this review.

Micafungin (Mycamine) for fungal infections

A new intravenous drug for prophylaxis and treatment of Candida infections.

Antifungal agents in children

Fungal pathogens are an increasingly recognized complication of organ transplantation and the ever more potent chemotherapeutic regimens for childhood malignancies. This article provides a brief overview of the current state of systemic antifungal therapy. Currently licensed drugs, including amphotericin B and its lipid derivates; 5-fluorocytosine; the azoles, including fluconazole, itraconazole, and voriconazole; and a representative of the new class of echinocandin agents, caspofungin, are discussed. Newer second-generation azoles (posaconazole and ravuconazole) and echinocandins (micafungin and anidulafungin) that are likely to be licensed in the United States in the next few years also are addressed.

Pharmacokinetic and maximum tolerated dose study of micafungin in combination with fluconazole versus fluconazole alone for prophylaxis of fungal infections in adult patients undergoing a bone marrow or peripheral stem cell transplant

In this dose escalation study, 74 adult cancer patients undergoing bone marrow or peripheral blood stem cell transplantation received fluconazole (400 mg/day) and either normal saline (control) (12 subjects) or micafungin (12.5 to 200 mg/day) (62 subjects) for up to 4 weeks. The maximum tolerated dose (MTD) of micafungin was not reached, based on the development of Southwest Oncology Group criteria for grade 3 toxicity; drug-related toxicities were rare. Commonly occurring adverse events considered related to micafungin were headache (6.8%), arthralgia (6.8%), hypophosphatemia (4.1%), insomnia (4.1%), maculopapular rash (4.1%), and rash (4.1%). Pharmacokinetic profiles for micafungin on days 1 and 7 were similar. The mean half-life was approximately 13 h, with little variance after repeated or increasing doses. Mean maximum concentrations of the drug in serum and areas under the concentration-time curve from 0 to 24 h were approximately proportional to dose. There was no clinical or kinetic evidence of interaction between micafungin and fluconazole. Five of 12 patients (42%) in the control group and 14 of 62 (23%) in the micafungin-plus-fluconazole groups had a suspected fungal infection during treatment which resulted in empirical treatment with amphotericin B. The combination of micafungin and fluconazole was found to be safe in this high-risk patient population. The MTD of micafungin was not reached even at doses up to 200 mg/day for 4 weeks. The pharmacokinetic profile of micafungin in adult cancer patients with blood or marrow transplants is consistent with the profile in healthy volunteers, and the area under the curve is proportional to dose.

Micafungin: pharmacology, experimental therapeutics and clinical applications

Invasive fungal infections are important causes of morbidity and mortality in hospitalised patients. Current therapy with amphotericin B and antifungal triazoles has overlapping targets and is limited by toxicity and resistance. Echinocandins are a new class of antifungal drugs, which inhibit the synthesis of 1,3-beta-D-glucan. This homopolysaccharide is an important component of the cell wall of many pathogenic fungi, providing osmotic stability and functioning in cell growth and cell division. Micafungin, which is a member of the echinocandin class, exhibits in vitro fungicidal or fungistatic activity against a variety of fungal pathogens which include Candida and Aspergillus species but not Cryptococcus, Fusarium or Zygomycetes. Micafungin demonstrates linear pharmacokinetics, which are not altered by drugs metabolised through the P450 enzyme system. The preclinical and clinical data strongly support the development of micafungin for treatment of proven or suspected mucosal and invasive Candida infections in immunocompetent and immunocompromised patients. This paper reviews the preclinical and clinical pharmacology of micafungin and its potential role for treatment of fungal invasive infections in patients.

Efficacy of micafungin against deep-seated candidiasis in cyclophosphamide-induced immunosuppressed mice

OBJECTIVES

We investigated the effects of fluconazole and micafungin for the therapy of deep-seated candidiasis in a cyclophosphamide-induced immunosuppressed mouse model.

METHODS

We used the experimental model of intraperitoneal fungal abscess caused by Candida albicans, as described previously.

RESULTS AND CONCLUSIONS

Micafungin efficacy was equal to that of fluconazole in one-tenth dosage even in peritonitis. We also assessed the short-term (24 h) and long-term (8 days) therapeutic effects after the end of therapy. Although the therapeutic effect of fluconazole was similar to that of micafungin at 24 h after the end of therapy, the effect of micafungin was superior to that of fluconazole at 8 days after the end of therapy.

[Sucessful treatment by micafungin of pulmonary aspergillosis occurring in an old lung abscess]

A 55-year-old man, who had diabetes from age 46 years old had been treated for a lung abscess in the right upper lobe at age 51. He underwent an operation for stomach cancer at age 52. When he was 55 years old, a cavity lesion appeared in his right upper lobe at the site of the treated lung abscess. Pulmonary aspergillosis was diagnosed by bronchial biopsy. In this case, we controlled his diabetes and used micafungin which has a mechanism unlike other conventional antifungal agents. The shadow decreased and examination of the resected specimen showed that the fungus had disappeard. Pulmonary aspergillosis is an important mycosis profunda and micafungin seems to be an effective antifungal agent against it.

Efficacy of micafungin in combination with other drugs in a murine model of disseminated trichosporonosis

Using a murine model of disseminated infection caused by Trichosporon asahii, we have evaluated the efficacies of amphotericin B (AMB; 1 mg/kg of body weight/day), fluconazole (FLC; 20 mg/kg/twice a day), and micafungin (MFG; 5 mg/kg/twice a day). We tested these drugs alone and in combination (MFG with AMB and MFG with FLC). MFG with AMB showed a synergistic effect and demonstrated a higher degree of efficacy in prolonging survival and reducing the kidney fungal burden than either agent alone. The combination MFG with FLC was able to reduce significantly the kidney fungal burden in comparison to that achieved with either drug administered alone.

Lipopeptides, focusing on daptomycin, for the treatment of Gram-positive infections

The increasing incidence of serious infections caused by antibiotic-resistant Gram-positive bacteria has led to the development of new spectrum-specific agents. One such agent is Cubicin (daptomycin for injection), the first member of a new class of antibacterials called cyclic lipopeptides. Daptomycin has rapid, concentration-dependent bactericidal activity against most clinically significant Gram-positive pathogens, including vancomycin-resistant enterococci, methicillin-resistant Staphylococcus aureus, and vancomycin-intermediate and -resistant S. aureus. This cyclic lipopeptide has a unique mechanism of action and exhibits a relatively prolonged concentration-dependent postantibiotic effect in vitro. In September 2003 the US FDA approved daptomycin for the treatment of complicated skin and skin-structure infections. With its once-daily dosing, excellent safety profile and low potential for resistance, daptomycin is a welcome new addition to the armamentarium against Gram-positive infections.

Potential use of (1,3)-beta-D-glucan as target of diagnosis and treatment of keratomycosis

PURPOSE

Major problems in the management of keratomycosis stem from the difficulty of its diagnosis and limited choice of antifungal agents. In the present paper we propose a new method of detecting (1,3)-beta-D-glucan, one of the major components of fungal cell wall, in tears from an animal model of keratomycosis. In addition, we investigated the efficacy of topical application of micafungin, a new antifungal agent that inhibits the activity of (1,3)-beta-D-glucan synthase in this animal model.

METHOD

Candida albicans (5 x 10(5) organisms) was inoculated into the corneal stroma of 20 New Zealand White rabbits. The animals were randomly assigned to two groups and treated with subconjunctival injection of 0.5 mL of saline or 0.1% micafungin every day for 3 weeks. The clinical course of keratomycosis in both groups was compared. Before and 3 weeks after the injection of saline or micafungin, 5 microL of tears in each eye were collected by capillary tube. The concentration of (1,3)-beta-D-glucan was quantitatively measured by modified Limulus test.

RESULTS

The concentration of (1,3)-beta-D-glucan was significantly higher in keratomycosis model animals than in controls (mean +/- SD, 17.4 +/- 9.4 pg/mL and 2.8 +/- 1.8 pg/mL, respectively) at 21 days after treatment. Subconjunctival injection of micafungin had no significant effect on ocular lesions of keratomycosis until 9 days, after which ocular lesions significantly improved. Subconjunctival application of micafungin decreased the concentration of (1,3)-beta-D-glucan in tears to 4.9 +/- 3.0 pg/mL at 21 days after treatment.

CONCLUSIONS

Increased levels of (1,3)-beta-D-glucan in tears were detected in this model of keratomycosis. Measuring the concentration of (1,3)-beta-D-glucan in tears may be a reliable noninvasive method for the diagnosis of keratomycosis. Topical application of micafungin was effective in the treatment of keratomycosis.

Successful Treatment with Micafungin (MCFG) of Severe Peritonitis Due to Candida parapsilosis with Chronic Renal Failure Patient on Hemodialysis

A 49 year-old woman with chronic renal failure (CRF) on continuous ambulatory peritoneal dialysis (CAPD) because of Goodpasture Syndrome was admitted to our hospital since she had a high fever and severe abdominal pain. A diagnosis of peritonitis was made from the physical examination and laboratory findings. The peritonitis was refractory to conventional antibiotics therapy. Candida parapsilosis was detected from dialysite. The peritonitis was aggravated although the antibiotic was changed to an antifungal agent (fluconazole 400mg/day). Fluconazole was replaced to micafungin (MCFG) and the catheter for CAPD was removed. The fungal peritonitis improved dramatically and beta-D glucan was decreased from 104 to 12.6 (pg/ml). No adverse effect was observed after using MCFG. It has been known that fungal peritonitis of CRF patients is refractory to treatment and the mortality rate is high. To our best knowledge, there is no report that MCFG was used for CRF patients with fungal peritonitis. However, we used MCFG safely and effectively for CRF patients. Therefore, it is suggested that MCFG is a new effective and safe antifungal agent for Candida parapsilosis peritonitis with CRF.

Retinal Function Assessed by ERG Before and After Induction of Ocular Aspergillosis and Treatment by the Anti-fungal, Micafungin, in Rabbits

This study was conducted to evaluate the effectiveness of a new antifungal drug, micafungin, and standard antifungal drugs against endophthalmitis induced in a rabbit by intravitreal injection of Aspergillus fumigatus, an important fungal pathogen. Effectiveness was evaluated by the preservation of b-wave amplitude at 72 h after injection of the fungus relative to the b-wave amplitude at baseline before any intravitreal injections. A 0.06 ml inoculum of 10(6) conidia of A. fumigatus was injected into the vitreous of the right eye of all rabbits; and, 12 h later, a 0.06 ml solution containing one of 3 antifungal drugs or saline was injected into the vitreous of both eyes. All three antifungal drugs produced significant b-wave preservation at 72 h in infected eyes compared to that in infected eyes receiving saline injections. There was no statistically significant difference between the effects of micafungin and amphotericin B in the right eyes with fungal endophthalmitis, and both produced significantly more preservation of b-wave amplitude than voriconazole. Amphotericin B, but neither micafungin nor voriconazole produced significant reduction of the b-wave amplitude in the left eyes.

Micafungin: a therapeutic review

In recent decades, the incidence of aspergillosis, candidiasis and clinically important deep mycoses has been increasing, with advances in transplantation medicine and anticancer chemotherapy. Micafungin (FK463, Fujisawa Healthcare) has been developed as a novel type of antifungal agent, which inhibits 1,3-beta-D-glucan synthase in the fungal cell wall. Micafungin, one of the echinocandins, exhibits extremely high antifungal activity against Aspergillus spp. and Candida spp. in vitro. It is also characterized by a linear pharmacokinetic profile and a much lower prevalence of adverse reactions than amphotericin B. Micafungin is quite useful in the treatment of deep mycoses. In clinical studies in Japan, micafungin was found to be highly effective against aspergillosis (57.1% overall efficacy rate) and candidiasis (78.6%). Micafungin is expected to increase the efficacy rate of treatment in patients with severe aspergillosis or candidiasis when used in combination with amphotericin B or mold azoles.

Combination antifungal therapy: where are we now, and where are we going?

Combination therapy with amphotericin B and flucytosine is considered to be the treatment of choice for cryptococcal infections. However, for other infections and combinations of antifungal infections, the data are less clear-cut. The concurrent use of amphotericin B with an azole has elicited controversy, given the potential of antimicrobial antagonism. The results of one recent candidemia study suggest that the potential antagonism may not be an issue; the combination of amphotericin B and fluconazole provided more effective clearance of Candida from the bloodstream than did fluconazole used alone. Several in vitro and animal studies have shown antagonism between the azoles and amphotericin B for aspergillosis. However, introduction of the new class of agents that target beta-glucan synthase (echinocandins) has invigorated the prospects of combination therapy. The echinocandins and polyenes are not antagonistic, and there is evidence that the echinocandins may provide additive to synergistic activity in combination with triazoles. For patients whose aspergillosis is progressing despite monotherapy, the addition of a second agent, such as an echinocandin, may be reasonable.

Micafungin versus fluconazole for prophylaxis against invasive fungal infections during neutropenia in patients undergoing hematopoietic stem cell transplantation

We hypothesized that chemoprophylaxis with the echinocandin micafungin would be an effective agent for antifungal prophylaxis during neutropenia in patients undergoing hematopoietic stem cell transplantation (HSCT). We therefore conducted a randomized, double-blind, multi-institutional, comparative phase III trial, involving 882 adult and pediatric patients, of 50 mg of micafungin (1 mg/kg for patients weighing <50 kg) and 400 mg of fluconazole (8 mg/kg for patients weighing <50 kg) administered once per day. Success was defined as the absence of suspected, proven, or probable invasive fungal infection (IFI) through the end of therapy and as the absence of proven or probable IFI through the end of the 4-week period after treatment. The overall efficacy of micafungin was superior to that of fluconazole as antifungal prophylaxis during the neutropenic phase after HSCT (80.0% in the micafungin arm vs. 73.5% in the fluconazole arm [difference, 6.5%]; 95% confidence interval, 0.9%-12%; P=.03). This randomized trial demonstrates the efficacy of an echinocandin for antifungal prophylaxis in neutropenic patients.

Efficacy of voriconazole plus amphotericin B or micafungin in a guinea-pig model of invasive pulmonary aspergillosis

The efficacy of voriconazole in combination with amphotericin B or micafungin was studied in a transiently neutropenic guinea-pig model of invasive pulmonary aspergillosis. Guinea-pigs treated with the antifungal drugs, alone or in two-drug combinations, had an improved survival rate and reduced fungal burden in the lungs compared to untreated control animals. The efficacy of monotherapy and combination therapy was similar; activity was neither enhanced nor reduced with the two-drug combinations. Further studies of efficacy, dosing and optimal regimens for antifungal combinations are warranted.

Micafungin

OBJECTIVE

To review the pharmacology, mycology, chemistry, in vitro susceptibility, pharmacokinetics, clinical efficacy, safety, tolerability, dosage, and administration of micafungin, an echinocandin antifungal agent.

DATA SOURCES

A MEDLINE search, restricted to English language, was conducted from 1978 to November 2003. Supplementary sources included program abstracts from the Interscience Conference on Antimicrobial Agents and Chemotherapy and the Infectious Diseases Society of America from 1996 to 2003 and information available through the manufacturer's Web site.

STUDY SELECTION AND DATA EXTRACTION

In vitro and preclinical studies, as well as Phase II and III clinical trials, were evaluated to summarize the clinical efficacy and safety of micafungin. All published and unpublished trials and abstracts citing micafungin were selected.

DATA SYNTHESIS

Micafungin has shown in vitro activity against many yeasts and a variety of molds. Micafungin can be administered only parenterally. Efficacy has been illustrated in open noncomparative studies of esophageal candidiasis in HIV-infected patients and in comparative trials as antifungal prophylaxis in patients undergoing hematopoietic stem-cell transplantation. Adverse events appear mild and limited; the most commonly reported adverse events include hyperbilirubinemia, nausea, and diarrhea.

CONCLUSIONS

Micafungin has activity against Aspergillus spp. and a variety of Candida spp., including azole-resistant strains. Micafungin demonstrates efficacy in the treatment of esophageal candidiasis in HIV-infected patients and appears superior to fluconazole as antifungal prophylaxis in patients undergoing hematopoietic stem-cell transplantation. Based on case reports and in vitro efficacy, micafungin may prove to be a clinically useful agent in the treatment of other fungal diseases; however, these indications await the results of clinical trials.

A Randomized, Double-Blind, Parallel-Group, Dose-Response Study of Micafungin Compared with Fluconazole for the Treatment of Esophageal Candidiasis in HIV-Positive Patients

BACKGROUND

Severely immunocompromised individuals are highly susceptible to Candida infection of the esophagus. This randomized, double-blind study assessed the dose-response relationship of the new echinocandin antifungal, micafungin, compared with that of standard fluconazole treatment.

METHODS

A total of 245 patients (age, > or =18 years) with a prior diagnosis of acquired immunodeficiency syndrome/human immunodeficiency virus (HIV) infection and esophageal candidiasis, confirmed by endoscopy and culture, were randomized to receive micafungin (50, 100, or 150 mg per day) or fluconazole (200 mg per day). Both agents were administered once per day by a 1-h intravenous infusion for 14-21 days. The primary efficacy end point was endoscopic cure rate, defined as endoscopy grade of 0 at the end of therapy.

RESULTS

The endoscopic cure rate (grade 0) was dose-dependent with 50, 100, and 150 mg of micafungin per day at 68.8%, 77.4%, and 89.8%, respectively. Symptoms improved or resolved rapidly (3-7 days of treatment in the majority of patients). The endoscopic cure rate for 100 and 150 mg of micafungin per day (83.5%) was comparable to that for 200 mg of fluconazole per day (86.7%; 95% confidence interval for the difference in endoscopic cure rate, -14.0% to 7.7%). The overall safety and tolerability was acceptable, with no important differences between micafungin (all doses) and fluconazole.

CONCLUSIONS

The dose-response findings demonstrate a greater efficacy with micafungin at 100 and 150 mg per day than at 50 mg per day. This study also indicates that the efficacy of micafungin (at dosages of 100 and 150 mg per day) was comparable to that of fluconazole, suggesting that micafungin represents a valuable new treatment option for esophageal candidiasis in HIV-positive patients.

Micafungin

Micafungin, an echinocandin antifungal agent with a novel mechanism of action, inhibits beta-(1,3)-D-glucan synthase interfering with fungal cell wall synthesis. It shows excellent antifungal activity against a broad range of Candida spp., including azole-resistant strains, and Aspergillus spp. in in vitro and animal studies. In HIV-positive patients, intravenous micafungin 50-150 mg/day dose-dependently eradicated endoscopically confirmed oesophageal candidiasis, with micafungin 100 and 150 mg/day being more effective than micafungin 50 mg/day and as effective as fluconazole 200 mg/day in a double-blind trial. In nonblind trials, micafungin (monotherapy or combination therapy) was effective against invasive aspergillosis, candidiasis and candidaemia in paediatric and adult patients with newly diagnosed or refractory infections. Micafungin 50 mg/day provided significantly better antifungal prophylaxis than fluconazole 400 mg/day in 882 haematopoietic stem cell transplant recipients in a randomised, double-blind trial. Respective overall success rates were 80% and 73.5%. Micafungin is generally well tolerated. Adverse events were not dose- or infusion-related with micafungin 12.5-900 mg/day; no histamine-like reactions occurred. Micafungin was as well tolerated as fluconazole, with numerically fewer micafungin recipients discontinuing treatment (4.2% vs 7.2%).

Recent applications of biosurfactants as biological and immunological molecules

The interest in microbial biosurfactants has steadily increased during the past decade. In addition to the classical application as emulsifiers of hydrocarbons, they can be used in environmental protection, crude-oil recovery, food-processing industries and in various fields of biomedicine. Biosurfactants have several advantages over chemical surfactants including lower toxicity and higher biodegradability, and are likely to become molecules of the future in areas such as biomedicine and therapeutics. Here, we discuss the role and applications of biosurfactants (mainly glycolipids and lipopeptides) focusing on medicinal and therapeutic perspectives.

Drug intervention trials in sepsis: divergent results

CONTEXT

Important advances have been made in our understanding of severe sepsis. Outcome can be improved by targeted interventions, including early and appropriate antibiotic therapy and goal-directed resuscitation, and might be further improved by selective decontamination of the digestive tract, tight control of glucose, and possibly by giving corticosteroids to selected patients. Drugs that target specific steps in the septic cascade include cytokine inhibitors, anti-endotoxins, and the three naturally occurring anticoagulants. Only one of these trials, which assessed the efficacy of activated protein C, reported significant improvements in outcome. Translation of these results into practice has been hampered by high drug costs, and by apparent discrepancies between interim results and final outcomes in two of the trials with natural anticoagulants.

STARTING POINT

Recently, Steven Opal and colleagues (Crit Care Med 2004; 32: 332-41) reported a randomised trial with platelet-activating-factor acetylhydrolase to suppress the inflammatory response in septic patients. No effects on outcome were observed (mortality 24% with placebo vs 25% with the intervention). By contrast, Jose Garnacho-Montero and colleagues, in a cohort study (Crit Care Med 2003; 31: 2742-51), saw large mortality reductions with initially appropriate choice of antibiotics in septic patients (19.8% reduction overall and 43.4% in patients with septic shock). These benefits were higher than those even in the most successful trial with an antisepsis agents, underscoring the importance of basic measures in severe sepsis. WHERE NEXT? Initial management in severe sepsis should include early goal-directed fluid resuscitation, appropriate antibiotic treatment, and surgical-site control. Intensive-care units should be run by specialists, with adequate medical and nursing staffing. Tight regulation of glucose, selective decontamination of the digestive tract, and moderate-dose corticosteroids in selected cases should be considered. Expensive new drugs, such as activated protein C, might further improve outcome, but should be considered only when organisational aspects and supportive care have been optimised.

Successful Micafungin (FK463) Treatment of Invasive Pulmonary Aspergillosis in a Patient with Acute Lymphoblastic Leukemia in a Phase II Study

We treated a 52-year-old woman with acute lymphoblastic leukemia (ALL) who developed invasive pulmonary aspergillosis (IPA) as a result of neutropenia following remission-induction chemotherapy. Although serological test results, such as those for platelia and pastrex, were all negative and the serum level of beta-D-glucan was low, Aspergillus DNA was detected in blood by the polymerase chain reaction method. A clinically documented diagnosis of IPA was made on the basis of chest x-rays, computed tomography scan findings, and the detection of Aspergillus DNA. Micafungin (FK463), a candin class antifungal agent, was administered at a dose of 75 to 150 mg/day, because other antifungal agents were not effective. The increase in serum concentration of micafungin was dose-dependent and was accompanied by improvement of symptoms and objective findings. Micafungin was effective for the treatment of IPA in this patient with ALL.

Pharmacologic treatment of acute renal failure in sepsis

The pathophysiology of acute renal failure in sepsis is complex and includes intrarenal vasoconstriction, infiltration of inflammatory cells in the renal parenchyma, intraglomerular thrombosis, and obstruction of tubuli with necrotic cells and debris. Attempts to interfere pharmacologically with these dysfunctional pathways, including inhibition of inflammatory mediators, improvement of renal hemodynamics by amplifying vasodilator mechanisms and blocking vasoconstrictor mechanisms, and administration of growth factors to accelerate renal recovery, have yielded disappointing results in clinical trials. Interruption of leukocyte recruitment is a potential promising approach in the treatment of septic acute renal failure, but no data in humans are presently available. Activated protein C and steroid replacement therapy have been shown to reduce mortality in patients with sepsis and are now accepted adjunctive treatment options for sepsis in general.

Guidelines for the Management of Deep Mycosis in Neutropenic Patients

Invasive fungal infections (IFIs) are a major cause of morbidity and mortality in neutropenic patients with leukemia and those undergoing hematopoietic stem cell transplant (HSCT). Two major IFIs are systemic candidiasis (including candidemia, chronic disseminated candidiasis and pneumonia) and invasive pulmonary aspergillosis. Recently, the incidence of the latter has been increasing. Three levels of diagnosis are specified in the Japanese guidelines for the diagnosis and treatment of IFIs. Proven fungal infections are diagnosed by histological/microbiological evidence of fungi at the site of infection or positive blood culture (fungemia). Clinically documented fungal infections are diagnosed by typical radiological findings such as halo sign on chest CT plus positive serological/molecular evidence of fungi such as Aspergillus galactomannan, beta-glucan or fungal DNA. Possible fungal infections are diagnosed by typical radiological findings or positive serological/molecular evidence of fungi. For patients with high risk such as those undergoing HSCT, antifungal prophylaxis using oral antifungal agents is recommended. For possible fungal infections, empiric therapy with fluconazole (FLCZ) or amphotericin B (AMPH) is recommended. For patients with proven fungal infections or clinically documented fungal infections, targeted therapy is warranted. In case of candidemia, the best choice is FLCZ (400 mg/day) or AMPH (0.5-0.7 mg/kg/day), and for invasive pulmonary aspergillosis, a higher dose of AMPH (1.0-1.5 mg/kg/day) is indicated. Micafungin (MCFG), recently licensed in Japan, is an active agent for both Candida and Aspergillus. This drug seems useful for empiric and targeted therapy of IFIs.

New treatment strategies for disseminated intravascular coagulation based on current understanding of the pathophysiology

A variety of clinical conditions may cause systemic activation of coagulation, ranging from insignificant laboratory changes to severe disseminated intravascular coagulation (DIC). DIC consists of a widespread systemic activation of coagulation, resulting in diffuse fibrin deposition in small and midsize vessels. There is compelling evidence from clinical and experimental studies that DIC is involved in the pathogenesis of microvascular dysfunction and contributes to organ failure. In addition, the massive and ongoing activation of coagulation, may result in depletion of platelets and coagulation factors, which may cause bleeding. Recent understanding of important pathogenetic mechanisms that may lead to DIC has resulted in novel preventive and therapeutic approaches to patients with sepsis and a derangement of coagulation. Thrombin generation proceeds via the (extrinsic) tissue factor/factor VIIa route and simultaneously occurring depression of inhibitory mechanisms, such as antithrombin III and the protein C system. Also, impaired fibrin degradation, due to high circulating levels of the fibrinolytic inhibitor plasminogen activator inhibitor, type 1 (PAI-1), contributes to enhanced intravascular fibrin deposition. Interestingly, an extensive cross-talk between activation of inflammation and coagulation exists, where inflammatory mediators (such as cytokines) not only activate the coagulation system, but vice versa activated coagulation proteases and protease inhibitors may modulate inflammation through specific cell receptors. Supportive strategies aimed at the inhibition of coagulation activation may theoretically be justified and have been found beneficial in experimental and initial clinical studies. These strategies comprise inhibition of tissue factor-mediated activation of coagulation or restoration of physiological anticoagulant pathways, for example by means of the administration of recombinant human activated protein C.

Infection and inflammation and the coagulation system

Severe infection and inflammation almost invariably lead to hemostatic abnormalities, ranging from insignificant laboratory changes to severe disseminated intravascular coagulation (DIC). Systemic inflammation results in activation of coagulation, due to tissue factor-mediated thrombin generation, downregulation of physiological anticoagulant mechanisms, and inhibition of fibrinolysis. Pro-inflammatory cytokines play a central role in the differential effects on the coagulation and fibrinolysis pathways. Vice-versa, activation of the coagulation system may importantly affect inflammatory responses by direct and indirect mechanisms. Apart from the general coagulation response to inflammation associated with severe infection, specific infections may cause distinct features, such as hemorrhagic fever or thrombotic microangiopathy. The relevance of the cross-talk between inflammation and coagulation is underlined by the promising results in the treatment of severe systemic infection with modulators of coagulation and inflammation.

Echinocandin antifungal drugs

The echinocandins are large lipopeptide molecules that are inhibitors of beta-(1,3)-glucan synthesis, an action that damages fungal cell walls. In vitro and in vivo, the echinocandins are rapidly fungicidal against most Candida spp and fungistatic against Aspergillus spp. They are not active at clinically relevant concentrations against Zygomycetes, Cryptococcus neoformans, or Fusarium spp. No drug target is present in mammalian cells. The first of the class to be licensed was caspofungin, for refractory invasive aspergillosis (about 40% response rate) and the second was micafungin. Adverse events are generally mild, including (for caspofungin) local phlebitis, fever, abnormal liver function tests, and mild haemolysis. Poor absorption after oral administration limits use to the intravenous route. Dosing is once daily and drug interactions are few. The echinocandins are widely distributed in the body, and are metabolised by the liver. Results of studies of caspofungin in candidaemia and invasive candidiasis suggest equivalent efficacy to amphotericin B, with substantially fewer toxic effects. Absence of antagonism in combination with other antifungal drugs suggests that combination antifungal therapy could become a general feature of the echinocandins, particularly for invasive aspergillosis.

Combination and sequential antifungal therapy for invasive aspergillosis: review of published in vitro and in vivo interactions and 6281 clinical cases from 1966 to 2001

The development of newer antifungal drugs is creating new potential combination therapies to combat the dismal mortality rate associated with invasive aspergillosis (IA). The efficacy of combination therapy for IA has not been established; sparse data on combination or sequential antifungal therapy depict interactions ranging from synergy to antagonism. We reviewed data from all published in vitro studies, animal model studies, and clinical reports and recent abstracts on combination and sequential antifungal therapy for IA from 1966-2001. Among cases of IA during 1966-2001, 249 were treated with 23 different antifungal combinations. Amphotericin B plus 5-fluorocytosine was the most commonly used (49% of cases), followed by amphotericin B plus itraconazole (16%) or plus rifampin (11%). Combination therapy resulted in improvement in 63% of patients, generally with amphotericin B plus 5-fluorocytosine or rifampin and indifference with amphotericin B plus itraconazole. In 27 in vitro reports, we found synergy (in 36% of reports), additivity (in 24%), indifference (in 28%), and antagonism (in 11%). Amphotericin B plus 5-fluorocytosine and amphotericin B plus rifampin showed generally positive interactions and amphotericin B plus itraconazole showed results that were largely indifferent. Eighteen animal model reports demonstrated synergy (in 14% of reports), additivity (in 20%), indifference (in 51%), and antagonism (in 14%). In general, amphotericin B plus 5-fluorocytosine, amphotericin B plus rifampin, and amphotericin B plus itraconazole showed indifferent results, whereas amphotericin B plus micafungin showed positive interactions. Thirty-four cases treated during 1990-2001 with sequential therapy, excluding amphotericin B followed by itraconazole, showed improvement in 68% of cases. Improvement was noted with amphotericin B or itraconazole followed by voriconazole but not with itraconazole followed by amphotericin B.

Successful treatment with micafungin of invasive pulmonary aspergillosis in acute myeloid leukemia, with renal failure due to amphotericin B therapy

Invasive aspergillosis is an important factor in the morbidity and mortality of patients suffering from hematologic disorders treated with chemotherapy. Treatment with amphotericin B is often limited because of toxicity, particularly nephrotoxicity. We describe a case of invasive pulmonary Aspergillus fumigatus infection in acute myeloid leukemia with renal failure due to amphotericin B therapy, which responded to treatment with a new antifungal agent, micafungin. Micafungin appears to be an effective and safe therapy for Aspergillus infections with renal failure due to amphotericin B.

Efficacy and safety of tifacogin (recombinant tissue factor pathway inhibitor) in severe sepsis: a randomized controlled trial

CONTEXT

The expression and release of tissue factor is a major trigger for the activation of coagulation in patients with sepsis. Tissue factor pathway inhibitor (TFPI) forms a complex with tissue factor and blood protease factors leading to inhibition of thrombin generation and fibrin formation.

OBJECTIVES

To determine if administration of tifacogin (recombinant TFPI) provides mortality benefit in patients with severe sepsis and elevated international normalized ratio (INR) and to assess tifacogin safety in severe sepsis, including patients with low INR.

DESIGN AND SETTING

A randomized, double-blind, placebo-controlled, multicenter, phase 3 clinical trial conducted from March 21, 2000, through September 27, 2001, in 245 hospitals in 17 countries in North America, Europe, and Israel.

PATIENTS

The primary efficacy population consisted of 1754 patients (> or =18 years) with severe sepsis and a high INR (> or =1.2) randomly assigned to intravenous infusion of either tifacogin (0.025 mg/kg per hour for 96 hours, n = 880) or placebo (arginine citrate buffer, n = 874), and 201 patients with a low INR (<1.2) randomly assigned to receive the same dose of either tifacogin or placebo.

MAIN OUTCOME MEASURE

All-cause 28-day mortality.

RESULTS

Overall mortality at 28 days in the tifacogin-treated group (n = 880) vs the placebo group (n = 874) for high INR was 34.2% vs 33.9%, respectively (P =.88, Pearson chi2 test; P =.75, logistic regression model). None of the protocol-specified secondary end points differed between the tifacogin vs placebo groups. An analysis on the first 722 patients demonstrated a mortality rate of 38.9% for placebo vs 29.1% for tifacogin (P =.006, Pearson chi2 test). Tifacogin significantly attenuated prothrombin fragment 1.2 and thrombin:antithrombin complex levels (P<.001, 2-sample t test) in patients with high and low INR. Overall mortality was lower in the tifacogin response in patients with low INR (12%; n = 83) vs placebo (22.9%; n = 118) (P =.051, Pearson chi2 test; P =.03, logistic regression model). There was an increase in serious adverse events with bleeding in the tifacogin group in both cohorts (6.5% tifacogin and 4.8% placebo for high INR; 6.0% tifacogin and 3.3% placebo for low INR).

CONCLUSIONS

Treatment with tifacogin had no effect on all-cause mortality in patients with severe sepsis and high INR. Tifacogin administration was associated with an increase in risk of bleeding, irrespective of baseline INR.

Tissue factor pathway inhibitors as a novel approach to antithrombotic therapy

Tissue factor is the initiator of the extrinsic pathway of the coagulation cascade. It is expressed by endothelial cells when stimulated by cytokines and other mediators. The effect of tissue factor is physiologically balanced by tissue factor pathway inhibitor. Atherosclerotic plaques are rich in tissue factor. It stimulates thrombus formation when plaques rupture. The emerging role of tissue factor in cellular signaling and in the pathogenesis of atherosclerosis has directed attention to inhibitors of tissue factor as a new antithrombotic approach. In comparison to currently used anticoagulants, tissue factor pathway inhibitors have the potential advantage of inhibiting the coagulation cascade at its earliest stage. These agents also act locally at the site of endothelial injury with minimal disturbance of systemic hemostasis. In addition, their inhibitory effect on neointimal formation and restenosis after vascular intervention are appealing features in the management of the complications of atherosclerosis.

Coagulation dysfunction in sepsis and multiple organ system failure

In patients diagnosed with sepsis, severe sepsis or septic shock, cytokine-mediated endothelial injury, and TF activation initiate a cascade of events that culminate in the development of coagulation dysfunction characterized as procoagulant and antifibrinolytic. This abnormal state predisposes the patient to develop microvascular thrombosis, tissue ischemia, and organ hypoperfusion. Multiple organ dysfunction syndrome may be a product of this pertubation in coagulation regulation. Treatments aimed at correcting this coagulation dysfunction have met with mixed success. Current data suggest that AT III replacement therapy has limited efficacy in adults with severe sepsis. In contrast, adult patients diagnosed with severe sepsis and organ failure and treated with aPC (drotrecogin alfa activate) have a significantly reduced risk of death when compared with placebo-treated patients. A phase III trial examining the efficacy of protein C replacement therapy in pediatric patients with severe sepsis and organ failure is underway.

A meta-analysis of controlled trials of anticoagulant therapies in patients with sepsis

Although coagulation abnormalities may partly underlie the physiologic derangements of the sepsis syndrome, anticoagulant therapies have produced mixed results on survival in clinical studies. We hypothesized that a meta-analysis of clinical trials of anticoagulants in sepsis may provide insight as to the therapeutic utility of targeting the clotting cascade in this syndrome. We searched electronic databases and reviewed bibliographies of pertinent articles to identify controlled clinical studies in which anticoagulants had been administered as adjunctive therapy to patients with sepsis. After establishing statistical homogeneity, odds ratios (OR; with 95% confidence intervals [CI]) for effect of these agents on mortality and bleeding complications were determined using Mantel-Haenszel methodology. Potential for publication bias was assessed by the use of a statistical test of funnel plot asymmetry. Weighted linear regression was performed to examine the effect of control group mortality rate on treatment efficacy. We identified 11 studies that satisfied our inclusion criteria. Collectively, these studies enrolled 4690 patients (range of 29-2314) and examined three agents: antithrombin III (2659 patients), tissue factor pathway inhibitor (210 patients), and activated protein C (1821 patients). After establishing statistical homogeneity (P > 0.10, chi-square), we found that the OR (with 95% CI) for effect on mortality for these agents, relative to control treatment, was 0.8692 (0.7519-1.006). Weighted linear regression analysis was consistent with a control group mortality dependent effect for these agents (P = 0.02). Only five of the studies reported bleeding complications. Pooling the results of these five studies (4376 patients) resulted in an OR (with 95% CI) of 1.70 (1.40-2.07) relative to control treatment for bleeding risk. Anticoagulants as adjuvant therapy do not appear to improve outcome in sepsis and are associated with a significant risk of bleeding complications. To the extent that their treatment effect is dependent upon disease severity, the safety and efficacy of these agents may be enhanced by refinement in techniques of clinical stratification.