Strategies to enhance immune function in hematopoietic transplantation recipients who have fungal infections

Treatment of disseminated nocardiosis: a host-pathogen approach with adjuvant interferon gamma

Disseminated nocardiosis is a rare, life-threatening disease. Particularly at risk are immunocompromised patients, highlighting the crucial role of host factors. Conventional intensive antibiotic treatment has improved survival rates, but the overall prognosis of patients with disseminated nocardiosis remains unsatisfactory. In this Grand Round, we present a case of severe nocardiosis that did not respond to standard therapy. The patient's condition deteriorated when antibiotic therapy was given alone and improved substantially only after coadministration of interferon gamma. We review the literature relevant to adjuvant interferon gamma therapy of nocardiosis and discuss its potential harms and benefits. Overall, we consider such treatment as beneficial and low risk if the patient is followed-up closely. We conclude that clinicians should consider this regimen in refractory cases of severe Nocardia infection.

Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection: let the virus be its own demise

There has been a collaborative global effort to construct novel therapeutic and prophylactic approaches to SARS-CoV-2 management. Although vaccine development is crucial, acute management of newly infected patients, especially those with severe acute respiratory distress syndrome, is a priority. Herein we describe the rationale and potential of repurposing a dual plasmid, Vigil (pbi-shRNA^furin-GM-CSF), now in Phase III cancer trials, for the treatment of and, in certain circumstances, enhancement of the immune response to SARS-CoV-2.

Microbiome: An Emerging New Frontier in Graft-Versus-Host Disease

Hematopoietic cell transplantation is an intensive therapy used to treat high-risk hematological malignant disorders and other life-threatening hematological and genetic diseases. Graft-versus-host disease (GVHD) presents a barrier to its wider application. A conditioning regimen and medications given to patients undergoing allogeneic hematopoietic stem cell transplantation (allo-HCT) are capable of disturbing the homeostatic crosstalk between the microbiome and the host immune system and of leading to dysbiosis. Intestinal inflammation in the context of GVHD is associated with loss in microbial diversity that could serve as an independent predictor of mortality. Successful gastrointestinal decontamination using high doses of non-absorbable antibiotics likely affect allo-HCT outcomes leading to significantly less acute GVHD (aGVHD). Butyrate-producing Clostridia directly result in the increased presence of regulatory T cells in the gut, which are protective in GVHD development. Beyond the microbiome, Candida, a member of the mycobiome, colonization in the gut has been considered as a risk factor in pathophysiology of aGVHD and reduction in GVHD is observed with antifungal prophylaxis with fluconazole. Reduced number of goblet cells and Paneth cells have been shown to associate with GVHD and has a significant impact on the micro- and mycobiome density and their composition. Lower levels of 3-indoxyl sulfate at initial stages after allo-HCT are related with worse GVHD outcomes and increased mortality. Increased understanding of the vital role of the gut microbiome in GVHD can give directions to move the field towards the development of improved innovative approaches for preventing or treating GVHD following allo-HCT.

Fungal Pneumonia in Patients with Hematologic Malignancy and Hematopoietic Stem Cell Transplantation

Fungal pneumonias cause unacceptable morbidity among patients with hematologic malignancies (HM) and recipients of hematopoietic stem cell transplantation (HSCT). The high incidence of fungal pneumonias in HM/HSCT populations arises from their frequently severe, complex, and persistent immune dysfunction caused by the underlying disease and its treatment. The cytopenias, treatment toxicities, and other immune derangements that make patients susceptible to fungal pneumonia frequently complicate its diagnosis and increase the intensity and duration of antifungal therapy. This article addresses the host factors that contribute to susceptibility, summarizes diagnostic recommendations, and reviews current guidelines for management of fungal pneumonia in patients with HM/HSCT.

Invasive fungal infections in the ICU: how to approach, how to treat

Invasive fungal infections are a growing problem in critically ill patients and are associated with increased morbidity and mortality. Most of them are due to Candida species, especially Candida albicans. Invasive candidiasis includes candidaemia, disseminated candidiasis with deep organ involvement and chronic disseminated candidiasis. During the last decades rare pathogenic fungi, such as Aspergillus species, Zygomycetes, Fusarium species and Scedosporium have also emerged. Timely diagnosis and proper treatment are of paramount importance for a favorable outcome. Besides blood cultures, several laboratory tests have been developed in the hope of facilitating an earlier detection of infection. The antifungal armamentarium has also been expanded allowing a treatment choice tailored to individual patients' needs. The physician can choose among the old class of polyenes, the older and newer azoles and the echinocandins. Factors related to patient's clinical situation and present co-morbidities, local epidemiology data and purpose of treatment (prophylactic, pre-emptive, empiric or definitive) should be taken into account for the appropriate choice of antifungal agent.

Aerosolized amphotericin B lipid complex as adjunctive treatment for fungal lung infection in patients with cancer-related immunosuppression and recipients of hematopoietic stem cell transplantation

STUDY OBJECTIVE

Aerosolized amphotericin B lipid complex (aeABLC) has been successfully used to prevent fungal disease. Experience with aeABLC as treatment of fungal lung disease is limited.

DESIGN

We evaluated the safety and efficacy of aeABLC adjunct therapy for fungal lung disease in a retrospective study of 32 immunosuppressed adults. All values are given as ± standard deviation.

SETTING

National Cancer Institute-designated Comprehensive Cancer Center.

PATIENTS

Acute leukemia (69%) and severe neutropenia (63%) were common. Fifty-six percent of patients had undergone allogeneic hematopoietic stem cell transplantation 185 ± 424 days prior to aeABLC was commenced.

MEASUREMENT AND MAIN RESULTS

High-dose corticosteroids were administered during aeABLC in 28% of patients. Fungal lung disease was proven or probable in 41% of patients. Most patients (78%) received concurrent systemic antifungal therapy for a median of 14 ± 18 days before aeABLC. The median cumulative aeABLC dose was 1050 ± 2368 mg, and the median duration of aeABLC therapy was 28 ± 130 days. Most patients (78%) received 50 mg aeABLC twice daily. Partial or complete resolution of fungal lung disease was noted in 50% of patients. In three patients (9%) modest cough, mild bronchospasm, and transient chest pain with accompanying nausea and vomiting resolved completely after discontinuation of aeABLC. No patient required hospitalization for drug toxicity or had a serious (grade III or IV) drug-related adverse event.

CONCLUSION

Treatment with aeABLC was tolerated without serious toxicity and may be considered in the setting of severe immunosuppression, cancer, and/or hematopoietic stem cell transplantation in patients with difficult-to-treat fungal lung disease.

Use of healthy-donor granulocyte transfusions to treat infections in neutropenic patients with myeloid or lymphoid neoplasms: experience in 74 patients treated with 373 granulocyte transfusions

BACKGROUND/AIMS

Despite limited evidence for efficacy, granulocyte transfusions (GTX) are used to prevent and treat opportunistic infections in patients with neutropenia.

METHODS

Three hundred and seventy-three GTX given to 74 patients were assessed retrospectively.

RESULTS

GTX were discontinued because of clinical improvement more often in patients with severe infections than in patients without severe infections (27 vs. 12%; p ≤ 0.002), whereas deaths resulted in discontinuation of GTX therapy less often in patients with severe infections than without (8 vs. 39%; p ≤ 0.002). Patients who died by 12 weeks after GTX initiation were more likely to have leukemia (p = 0.03), not to have recovery of neutrophil counts (p < 0.0001), and to have started GTX during a critical care unit stay (p < 0.001). Uses of granulocyte colony-stimulating factor (p ≤ 0.02) and interferon-γ (p ≤ 0.04) were more common in patients who survived. In patients with comorbidities (31%; odds ratio, OR, 12.6; 95% confidence interval, CI, 2.4-65.7; p ≤ 0.003), GTX was started in the critical care unit (OR 8.8; 95% CI 2.5-30.9; p < 0.001), and a high total bilirubin level at the end of GTX (OR 2.1; 95% CI 1.1-4.2; p = 0.03) had a higher probability of death 12 weeks after GTX therapy commenced.

CONCLUSIONS

The possibility that a niche population may benefit from GTX requires further assessment.

Granulocyte macrophage colony-stimulating factor in 66 patients with myeloid or lymphoid neoplasms and recipients of hematopoietic stem cell transplantation with invasive fungal disease

BACKGROUND/AIMS

Adding granulocyte macrophage colony-stimulating factor (GM-CSF) may improve the response to antifungal therapy in immunosuppressed patients with invasive fungal disease (IFD).

METHODS

We retrospectively assessed 66 patients in whom GM-CSF was given during antifungal therapy.

RESULTS

Severe neutropenia (77%) and refractory/relapsed cancer (65%) were common in the group. Prior to GM-CSF therapy, 15% of patients received high-dose corticosteroids for a median of 30 ± 16 days [median cumulative dose (c.d.) 1,184 ± 1,019 mg], and 9 received steroids during GM-CSF therapy for a median of 16 ± 12 days (median c.d. 230 ± 1,314 mg). Mild toxic effects were noted in 9% of patients; there were no cases of cardiopulmonary toxicity. All-cause deaths were observed in 68% of patients and 48% died of progressive IFD. High-dose corticosteroids prior to GM-CSF (OR 24; 95% CI 2.21-264.9; p ≤ 0.009), GM-CSF started in the intensive care unit (OR 10; 95% CI 1.66-63.8; p ≤ 0.01), concurrent granulocyte transfusions (OR 5; 95% CI 1.27-16.8; p ≤ 0.02) and proven/probable IFD (OR 4; 95% CI 1-16.2; p ≤ 0.05) predicted antifungal treatment failure.

CONCLUSIONS

GM-CSF adjuvant therapy was tolerated without serous toxicity and antifungal treatment failure remained a challenge in patients treated with high-dose systemic corticosteroids.

Immunotherapy against invasive mold infections

Invasive infections due to filamentous fungi, such as Aspergillus spp., Zygomycetes, Scedosporium and Fusarium spp., cause significant morbidity and mortality in immunocompromised patients with hematological malignancies, recipients of hematopoietic stem cell transplants and those with chronic granulomatous disease. Despite antifungal therapy, the outcome is often unfavorable in these patients; immune restoration is considered as the cornerstone of successful treatment. Important aspects of human immune response against fungi include effective innate immune response expressed as effective phagocytic functions and a balance between proinflammatory and regulatory adaptive immune responses. A number of immunomodulatory approaches, including the administration of enhancing cytokines, adoptive transfer of pathogen-specific T lymphocytes and granulocyte transfusions have been investigated as adjunctive treatments against serious mold infections. Despite encouraging in vitro and in vivo data, current clinical evidence is not sufficient to allow firm recommendations on the use of these immunomodulatory modalities in serious mold infections.

Immunotherapy of infections caused by rare filamentous fungi

Invasive fungal infections caused by rare filamentous fungi constitute a significant cause of morbidity and mortality in patients with defective immune responses. Despite the advent of new antifungal agents, the problem is escalating as the number of susceptible hosts increases and virulent, more resistant fungal strains emerge. There is evidence that reconstitution of the host immune function is a major contributor to the resolution of these infections. Therapeutic modalities aimed at increasing phagocyte numbers, such as granulocyte transfusions, stimulating the immune response, such as administration of haematopoietic growth factors and other proinflammatory cytokines, or indirectly augmenting immune function have shown promising results in the preclinical setting. Because of the rarity of the infections, multicentre clinical trials are needed to demonstrate the efficacy and safety of the new immunomodulating approaches.

Immunotherapy of aspergillosis

Management of invasive aspergillosis in high-risk patients remains challenging. There is an increasing demand for novel therapeutic strategies aimed at enhancing or restoring antifungal immunity in immunocompromised patients. In this regard, modulation of specific innate immune functions and vaccination are promising immunotherapeutic strategies. Recent findings have also provided a compelling rationale for assessment of the contribution of the individual genetic profile to the immunotherapy outcome. Altogether, integration of immunological and genetic data may contribute to the optimization of therapeutic strategies exerting control over immune pathways, ultimately improving the management of fungal infections in high-risk settings.

Infections in patients with hematologic neoplasms and hematopoietic stem cell transplantation: neutropenia, humoral, and splenic defects

Infections are common in patients with hematologic neoplasms and following allogeneic hematopoietic transplantation. Neutropenia and defects in adaptive B-cell-mediated immunity and/or lack of splenic function predispose patients to a host of diverse and often serious infections. It is important to recognize that patients who undergo treatment for hematologic neoplasms may have mixed immune defects, and their vulnerability to infection may continue to change, in part as a reflection of the dynamic developments in the practice of oncology. The main obstacle in providing targeted, evidence-based antimicrobial treatment is the unpredictable results of even the new generation of diagnostic assays. A definite diagnosis for most end-organ opportunistic diseases requires tissue samples that are seldom available. Because immune defects may coexist, empirical therapy is directed toward a wide spectrum of pathogens. Real-time information about innate and adaptive immune functions and the role of acute and chronic phase molecules may improve target-specific therapy.

Human NK cells display important antifungal activity against Aspergillus fumigatus, which is directly mediated by IFN-γ release

Despite the strong interest in the NK cell-mediated immunity toward malignant cells and viruses, there is a relative lack of data on the interplay between NK cells and filamentous fungi, especially Aspergillus fumigatus, which is the major cause of invasive aspergillosis. By studying the in vitro interaction between human NK cells and A. fumigatus, we found only germinated morphologies to be highly immunogenic, able to induce a Th1-like response, and capable of upregulating cytokines such as IFN-γ and TNF-α. Moreover, priming NK cells with human rIL-2 and stimulating NK cells by direct NK cell-pathogen contact were essential to induce damage against A. fumigatus. However, the most interesting finding was that NK cells did not mediate anti-Aspergillus cytotoxicity through degranulation of their cytotoxic proteins (perforin, granzymes, granulysine), but via an alternative mechanism involving soluble factor(s). To our knowledge, our study is the first to demonstrate that IFN-γ, released by NK cells, directly damages A. fumigatus, attributing new properties to both human NK cells and IFN-γ and suggesting them as possible therapeutic tools against IA.

Immunotherapy against invasive fungal diseases in stem cell transplant recipients

Despite the availability of new antifungal compounds, morbidity and mortality of invasive fungal disease in allogeneic hematopoietic stem cell recipients are still unacceptably high. Over the past decade, one could witness an exciting improvement of the understanding of the molecular pathogenesis and of the complexity of host antifungal immune responses. This, in turn, provides critical information to augment host immunity against fungal pathogens. Strategies for enhancing the immune system include the administration of effector and regulatory cells (e.g., granulocytes, antigen-specific T cells, dendritic cells) as well as the administration of recombinant cytokines, interferons and growth factors (e.g., interferon-γ, keratinocyte growth factor, granulocyte- and granulocyte-macrophage colony stimulating factor). One has to recognize at the same time, however, that data of in vitro assays and animal models cannot necessarily be transferred into the clinical setting. In addition, meaningful clinical trials in allogeneic stem cell recipients suffering from invasive fungal disease require sufficiently large and homogenous cohorts of patients and can only be performed in international collaboration, but may ultimately improve the outcome of allogeneic transplant recipients with invasive fungal disease.

Infections in Patients with Cancer: Overview

Patients with neoplastic disease are often highly susceptible to severe infections. The following factors influence the types, severity, and response to therapy of these infections: (1) Changing epidemiology of infections; (2) cancer- and/or treatment-associated neutropenia; (3) acquired immune deficiency states such as cellular immune defect; (4) recent development of new-generation diagnostic tools including widely available DNA amplification tests; (5) effective intervention for infection prevention; (6) empiric or presumptive therapy during high-risk periods; (7) availability of new classes of highly active antimicrobial drugs; (8) strategies to promote hosts’ immune response; and (9) future measures. This introductory chapter intended for the reader to become familiar with the important historical milestones in the understanding and development in the field of infectious diseases in immunosuppressed patients with an underlying neoplasms and patients undergoing hematopoietic stem cell trans­plantation.

Aspergillosis in hematopoietic stem cell transplant recipients: risk factors, prophylaxis, and treatment

This article discusses newer antifungal agents, recent randomized controlled trials, and the 2008 guidelines for treatment of aspergillosis in reference to hematopoietic stem cell transplantation (HSCT). Strategies such as reduced-intensity conditioning and agents such as infliximab shed new light on aspergillosis risk. The association between Toll-like receptor polymorphisms and aspergillosis is an exciting development. Posaconazole was evaluated in two randomized prophylaxis trials, and a large, randomized trial established voriconazole's therapeutic superiority to amphotericin. However, many questions remain regarding which patients benefit most from prophylaxis; resistance to newer antifungals; and combination, salvage, and immunomodulatory therapies. Current therapies and strategies have improved the outlook of HSCT recipients with invasive aspergillosis. Future directions include increasingly sophisticated risk stratification, clinical testing of combination therapies, and adjunctive immunomodulatory therapies.

Inhaled therapeutics for prevention and treatment of pneumonia

The lungs are the most common site of serious infection owing to their large surface area exposed to the external environment and minimum barrier defense. However, this architecture makes the lungs readily available for topical therapy. Therapeutic aerosols include those directed towards improving mucociliary clearance of pathogens, stimulation of innate resistance to microbial infection, cytokine stimulation of immune function and delivery of antibiotics. In our opinion inhaled antimicrobials are underused, especially in patients with difficult-to-treat lung infections. The use of inhaled antimicrobial therapy has become an important part of the treatment of airway infection with Pseudomonas aeruginosa in cystic fibrosis and the prevention of invasive fungal infection in patients undergoing heart and lung transplantation. Cytokine inhaled therapy has also been explored in the treatment of neoplastic and infectious disease. The choice of pulmonary drug delivery systems remains critical as air-jet and ultrasonic nebulizer may deliver sub-optimum drug concentration if not used properly. In future development of this field, we recommend an emphasis on the study of the use of aerosolized hypertonic saline solution to reduce pathogen burden in the airways of subjects infected with microbes of low virulence, stimulation of innate resistance to prevent pneumonia in immunocompromised subjects using cytokines or synthetic pathogen-associated molecular pattern analogues and more opportunities for the use of inhaled antimicrobials. These therapeutics are still in their infancy but show great promise.

Recent advances in antifungal prevention and treatment

Invasive fungal infections are important causes of morbidity and mortality in patients with bone marrow failure syndromes and hematological malignancies, or who are undergoing allogeneic hematopoietic stem cell transplantation (HSCT). Current epidemiological trends indicate a shift toward infections by Aspergillus spp., non-albicans Candida spp., and previously uncommon fungal pathogens that have decreased susceptibility to the available antifungal agents. The last two decades have seen substantial improvements in the clinical, laboratory, and radiological diagnosis of these infections and the development of new antifungal compounds. Progress has been made in establishing disease definitions and paradigms for antifungal intervention and in the design and conduct of interventional clinical trials. Collectively, these advances have led to major but ongoing changes in the management of patients at risk of or being affected by invasive fungal infections. This article reviews current approaches to prevention and treatment of opportunistic fungal infections in immunocompromised patients with hematological disorders and discusses novel approaches to antifungal chemotherapy and adjunctive treatments.

Recommendations for the treatment of established fungal infections

Evidence-based guidelines for the treatment of established fungal infections in the adult haematology/oncology setting were developed by a national consensus working group representing clinicians, pharmacists and microbiologists. These updated guidelines replace the previous guidelines published in the Internal Medicine Journal by Slavin et al. in 2004. The guidelines are pathogen-specific and cover the treatment of the most common fungal infections including candidiasis, aspergillosis, cryptococcosis, zygomycosis, fusariosis, scedosporiosis, and dermatophytosis. Recommendations are provided for management of refractory disease or salvage therapies, and special sites of infections such as the cerebral nervous system and the eye. Because of the widespread use newer broad-spectrum triazoles in prophylaxis and empiric therapy, these guidelines should be implemented in concert with the updated prophylaxis and empiric therapy guidelines published by this group.

Current and future therapeutic options in the management of invasive aspergillosis

The past decade has witnessed significant progress in the management of invasive aspergillosis. Potent, relatively non-toxic antifungal drugs, data on early chest CT scanning and the availability of a non-invasive diagnostic test (serum galactomannan) are the key advances; among these, the contribution of the recently available drugs is the most significant. Safer and earlier intervention resulting in reduced mortality and improved outcome is being demonstrated. Newer strategies enable clinicians to provide drug therapy in a highly targeted manner, such that empirical use of antifungal drugs may decline. Voriconazole has become the drug of choice for primary therapy, while posaconazole shows promise as a prophylactic drug. Echinocandins are effective for salvage therapy and are under evaluation for primary therapy. Preliminary data for efficacy of combination therapy with a mould-active azole plus an echinocandin are of promise and clinical trials are under way. Reports of emergence of less-susceptible Aspergillus spp. during azole therapy are of concern and close monitoring is needed. Remarkably, the era of polyenes appears to be nearing the end in the therapy of invasive aspergillosis. The promise of newer classes of drugs, immune-modulating therapies and vaccines are exciting future additions to the arsenal against invasive aspergillosis.

Evolving strategies in the management of aspergillosis

Aspergillus spp. remain the most common causes of invasive mould infections among patients with hematologic malignancies and recipients of solid-organ and hematopoietic stem-cell transplants. Despite advances in prevention and treatment, invasive aspergillosis continues to be a deadly disease. This paper reviews current approaches to treatment of aspergillosis in adults, including surgical and immune-based strategies, and developments in prophylaxis for aspergillosis in high-risk patient populations.

Minimizing the risk of recurrent or progressive invasive mold infections during stem cell transplantation or further intensive chemotherapy

The risk of recurrence or progression of prior invasive fungal infection, predominantly due to molds, is 11-33% during subsequent stem cell transplantations or myelosuppressive chemotherapy, with a high mortality. Risk factors at the time of transplant include active infection and having received <6 weeks of antifungal therapy, while after transplant prolonged neutropenia and graft-versus-host disease requiring aggressive immunosuppression are important. The use of peripheral blood stem cells has been associated with a lower risk. Minimal data are available regarding the role of preventative strategies such as surgical resection of pulmonary lesions and prophylactic granulocyte transfusions during neutropenia, the optimal duration of antifungal prophylaxis, and the appropriate monitoring strategy. This article critically evaluates these issues and provides recommendations for the secondary prophylaxis of invasive mold infections.

Hematopoietic Growth Factors Including Keratinocyte Growth Factor in Allogeneic and Autologous Stem Cell Transplantation

The aim of hematopoietic stem cell transplantation (HSCT) is to cure patients of malignancies, autoimmune diseases, and immunodeficiency disorders by redirecting the immune system: the often described graft-versus-leukemia (GVL) or graft-versus-tumor (GVT) effects. Unfortunately, fulfillment of this goal is often hampered by relapse of the underlying disease, graft-versus-host disease (GVHD), or severe opportunistic infections, which account for the majority of post-transplantation deaths. Moreover, studies of long-term survivors of transplantation indicate an accelerated immune aging due to the transplantation procedure itself, preceding chemo- or radiotherapy, and acute and chronic GVHD. Significant advances have been made towards overcoming these obstacles by enhancing immune reconstitution with hematopoietic growth factors (HGFs) such as granulocyte colony-stimulating factor (G-CSF) or erythropoietin (EPO) or through the application of cytokines. In addition, there are approaches to promote the thymic-dependent development of naive T cells, which are prepared for the interaction with a multitude of pathogens. Examples are the application of keratinocyte growth factor (KGF), neuroendocrine hormones such as growth hormone or prolactin, sex hormone ablation, or the invention of a three-dimensional artificial thymus based on a cytomatrix. Might these measures result in a higher rate of healthy and fully recovered patients? Here we review progress in each of these areas.

Efficacy of caspofungin as secondary prophylaxis in patients undergoing allogeneic stem cell transplantation with prior pulmonary and/or systemic fungal infection

Transplanted patients with a history of invasive fungal infection (IFI) are at high risk of developing relapse and fatal complications. Eighteen patients affected by hematological malignancies and a previous IFI were submitted to allogeneic stem cell transplantation, using Caspofungin as a secondary prophylaxis. Patients had a probable or proven fungal infection and 16 had a pulmonary localization. No side effects were recorded during treatment with Caspofungin. Compared to pre-transplant evaluation, stability or improvement of the previous IFI was observed in 16 of the 18 patients at day 30, in 13 of the 15 evaluable patients at day 180 and in 11 of the 11 evaluable patients at day 360 post transplant. In particular, all the six patients with a proven fungal infection were alive, with a stable or improved IFI after 1 year from transplant. At a maximum follow-up of 31 months, eight patients died for disease progression or transplant-related complications, but only two had evidence of fungal progression. Secondary prophylaxis with Caspofungin may represent a suitable approach to limit IFI relapse or progression, allowing patients with hematological malignancies to adhere to the planned therapeutic program.

High-dose caspofungin combination antifungal therapy in patients with hematologic malignancies and hematopoietic stem cell transplantation

Pneumocandins have concentration-dependent antifungal activity and higher dose of caspofungin (HD-CAP) in combination with other licensed antifungal therapy (OLAT) may improve response. Thirty-four patients who received HD-CAP were compared with 63 patients who received standard dose (SD)-CAP. There were no differences between the groups in either patient or disease characteristics. Significantly more patients in the HD-CAP arm had extrapulmonary infections (29 vs 8% in SD group; P=0.0053), and non-Aspergillus species infection (21 vs 6%; P=0.05) and had received prior antifungal therapy (71 vs 33%; P=0.0004). No serious adverse reactions were noted in patients receiving HD- or SD-CAP therapy. Twelve weeks after treatment commenced 44% had a complete or partial response compared with 29% in SD-CAP group (P=0.1). Logistic regression analysis showed a significant probability of a favorable outcome at 12 weeks in patients who received HD-CAP (OR 3.066, 95% CI, 1.092-8.61; P=0.033). This may in part reflect higher number of patients in HD group had received granulocyte-macrophage colony-stimulating factor (41 vs 14% in SD group; P=0.04) and/or interferon gamma (26 vs 5% in SD group; P=0.003) immune enhancement. Further studies are needed to evaluate efficacy of HD-CAP in severely immunosuppressed cancer patients with invasive fungal infections.