Therapeutic drug monitoring of antifungal therapies: do we really need it and what are the best practices?

INTRODUCTION: Despite advancements, invasive fungal infections (IFI) still carry high mortality rates, often exceeding 30%. The challenges in diagnosis, coupled with limited effective antifungal options, make managing IFIs complex. Antifungal drugs are essential for IFI management, but their efficacy can be diminished by drug-drug interactions and pharmacokinetic variability. Therapeutic Drug Monitoring (TDM), especially in the context of triazole use, has emerged as a valuable strategy to optimize antifungal therapy. AREAS COVERED: This review provides current evidence regarding the potential benefits of TDM in IFI management. It discusses how TDM can enhance treatment response, safety, and address altered pharmacokinetics in specific patient populations. EXPERT OPINION: TDM plays a crucial role in achieving optimal therapeutic outcomes in IFI management, particularly for certain antifungal agents. Preclinical studies consistently show a link between therapeutic drug levels and antifungal efficacy. However, clinical research in mycology faces challenges due to patient heterogeneity and the diversity of fungal infections. TDM's potential advantages in guiding Echinocandin therapy for critically ill patients warrant further investigation. Additionally, for drugs like Posaconazole, assessing whether serum levels or alternative markers like saliva offer the best measure of efficacy is an intriguing question.

Overview of invasive fungal infections in children in South America - the threat of resistant Candida species and the role of climate change in the new geographic distribution of endemic systemic mycosis.

PURPOSE OF REVIEW: Invasive fungal infection (IFI) in children is a growing problem with crescent morbidity and mortality, well recognized in developed countries, affecting mainly immunocompromised children, including neonates and children in intensive care units. The burden of IFI in South American children is less well comprehended. In addition, the current epidemiology of endemic systemic mycoses in children may have changed over time. RECENT FINDINGS: Candida spp. infections are very prevalent in South America hospitalized children, especially in neonates, in a rate far superior compared to developed countries. C. auris, has already been responsible for outbreaks in neonates and children in Venezuela and Colombia. Sporotrichosis is well established as an urban zoonosis in impoverish families. Paracoccidioidomycosis and histoplasmosis are affecting new areas of Brazil, probably due to climate change, deforestation, and human migration. SUMMARY: This review aims to unveil the real dimension of these infections in South American children. Hopefully, the awareness brought by this review will help healthcare professionals to recognize IFI more easily and it will provide support for getting more resources for IFI treatment and prevention.

Laboratory and clinical management capacity for invasive fungal infections: the Italian landscape.

BACKGROUND: We assessed the laboratory diagnosis and treatment of invasive fungal disease (IFD) in Italy to detect limitations and potential for improvement. METHODS: The survey was available online at www.clinicalsurveys.net/uc/IFI management capacity/, and collected variables such as (a) institution profile, (b) perceptions of IFD in the respective institution, (c) microscopy, (d) culture and fungal identification, (e) serology, (f) antigen detection, (g) molecular tests, (h) susceptibility testing and (i) therapeutic drug monitoring (TDM). RESULTS: The laboratory capacity study received responses from 49 Italian centres, with an equitable geographical distribution of locations. The majority of respondents (n = 36, 73%) assessed the occurrence of IFD as moderate-high, with Aspergillus spp. being the pathogen of highest concern, followed by Candida spp. and Mucorales. Although 46 (94%) of the institutions had access to microscopy, less than half of them performed direct microscopy on clinical specimens always when IFD was suspected. Cultures were available in all assessed laboratories, while molecular testing and serology were available in 41 (83%), each. Antigen detection tests and antifungal drugs were also generally accessible (> 90%) among the participating institutions. Nevertheless, access to TDM was limited (n = 31, 63%), with a significant association established between therapeutic drug monitoring availability and higher gross domestic product per capita. CONCLUSIONS: Apart from TDM, Italy is adequately prepared for the diagnosis and treatment of IFD, with no significant disparities depending on gross domestic product. Future efforts may need to focus on enhancing the availability and application of direct microscopic methods, as well as TDM, to promote optimal treatment and better patient outcomes.

[Enlightenment of World Health Organization fungal priority pathogens list].

The WHO established the first fungal priority pathogens list (FPPL) in October 2022 to focus on and promote further research and policy interventions to strengthen the global response to fungal infections and antifungal resistance. The FPPL and its formulation process provide new significant insights for managing pathogenic fungi and invasive fungal disease (IFD) in China, necessitating the following key actions: Strengthen public health interventions for IFD. Further, it improves the ability of laboratory testing and clinical supervision for IFD and pathogenic fungi. Increase targeted investment and support for innovative research and development in IFD diagnosis, treatment, and prevention.

[Research advances on invasive fungal infections after burns].

Invasive fungal infection (IFI) is one of the serious complications in burn patients. The gradual development and application of broad-spectrum antibiotics in recent years has led to a serious dysbiosis of the flora, while the widespread prophylactic use of antifungal drugs has led to an increasing number of drug-resistant fungi. The clinical treatment of IFI is difficult and the prognosis is poor. The mortality of burn patients caused by IFI is increasing year by year. This paper reviews the epidemiologic characteristics, related risk factors, diagnostic methods, and treatment progress of IFI after burns, aiming to provide new ideas and reference for the prevention and treatment of IFI after burns.

An update on the global treatment of invasive fungal infections.

Fungal infections are a serious problem affecting many people worldwide, creating critical economic and medical consequences. Fungi are ubiquitous and can cause invasive diseases in individuals mostly living in developing countries or with weakened immune systems, and antifungal drugs currently available have important limitations in tolerability and efficacy. In an effort to counteract the high morbidity and mortality rates associated with invasive fungal infections, various approaches are being utilized to discover and develop new antifungal agents. This review discusses the challenges posed by fungal infections, outlines different methods for developing antifungal drugs and reports on the status of drugs currently in clinical trials, which offer hope for combating this serious global problem.

Antifungal therapy: Novel drug delivery strategies driven by new targets.

In patients with compromised immunity, invasive fungal infections represent a significant cause of mortality. Given the limited availability and drawbacks of existing first-line antifungal drugs, there is a growing interest in exploring novel targets that could facilitate the development of new antifungal agents or enhance the effectiveness of conventional ones. While previous studies have extensively summarized new antifungal targets inherent in fungi for drug development purposes, the exploration of potential targets for novel antifungal drug delivery strategies has received less attention. In this review, we provide an overview of recent advancements in new antifungal drug delivery strategies that leverage novel targets, including those located in the physio-pathological barrier at the site of infection, the infection microenvironment, fungal-host interactions, and the fungal pathogen itself. The objective is to enhance therapeutic efficacy and mitigate toxic effects in fungal infections, particularly in challenging cases such as refractory, recurrent, and drug-resistant invasive fungal infections. We also discuss the current challenges and future prospects associated with target-driven antifungal drug delivery strategies, offering important insights into the clinical implementation of these innovative approaches.

Primary prophylaxis of invasive fungal diseases in patients with haematological malignancies: 2022 update of the recommendations of the Infectious Diseases Working Party (AGIHO) of the German Society for Haematology and Medical Oncology (DGHO).

Patients with haematological malignancies (HM) are at high risk of developing invasive fungal disease (IFD) with high morbidity and attributable mortality. We reviewed data published until September 2021 to update the 2017 antifungal prophylaxis recommendations of the German Society of Haematology and Medical Oncology (DGHO). The strong recommendation to administer antifungal prophylaxis in patients with HM with long-lasting neutropenia, i.e. <500 cells/µL for >7 days remains unchanged. Posaconazole remains the drug of choice for mould-active prophylaxis in these patients. Novel treatment options in HM, such as CAR-T-cell treatment or novel targeted therapies for acute myeloid leukaemia (AML) were considered, however, data are insufficient to give general recommendations for routine antifungal prophylaxis in these patients. Major changes regarding specific recommendations compared to the 2017 edition are the now moderate instead of mild support for the recommendations of isavuconazole and voriconazole. Furthermore, published evidence on micafungin allows recommending it at moderate strength for its use in HM. For the first time we included recommendations for non-pharmaceutical measures regarding IFD, comprising the use of high-efficiency particulate air (HEPA) filters, smoking, measures during construction work and neutropenic diets. We reviewed the impact of antifungal prophylaxis with triazoles on drug-drug interactions with novel targeted therapies that are metabolized via cytochrome p450 where triazoles inhibit CYP3A4/5. The working group recommends reducing the dose of venetoclax when used concomitantly with strong CYP3A4 inhibiting antifungals. Furthermore, we reviewed data on the prophylactic use of novel antifungal agents. Currently there is no evidence to support their use in a prophylactic setting in clinical practice.

Post-hoc analysis of the safety and efficacy of isavuconazole in older patients with invasive fungal disease from the VITAL and SECURE studies.

Isavuconazole is a triazole with broad-spectrum antifungal activity. In this post-hoc analysis of two prospective clinical trials (VITAL and SECURE), the safety and efficacy of isavuconazole in patients aged ≥ 65 years with invasive fungal diseases were evaluated. Patients were divided into two subgroups (≥ 65 and < 65 years). Adverse events (AEs); all-cause mortality; and overall, clinical, mycological, and radiological response were assessed. A total of 155 patients ≥ 65 years were enrolled in both trials. Most patients reported AEs. In the isavuconazole arm of both studies, serious AEs (SAEs) were greater in patients ≥ 65 versus < 65 years: 76.7% versus 56.9% (VITAL); 61.9% versus 49.0% (SECURE). In SECURE, SAE rates were similar in the ≥ 65 years subgroup of both treatment arms (61.9% vs 58.1%), while in the < 65 years subgroup the SAE rate was lower in the isavuconazole arm (49.0% vs 57.4%). In VITAL, all-cause mortality through day 42 (30.0% vs 13.8%) was higher, and overall response at end of treatment (27.6% vs 46.8%) was lower in patients ≥ 65 years versus < 65 years. In SECURE, all-cause mortality was similar between both subgroups, and isavuconazole (20.6% vs 17.9%) and voriconazole (22.6% vs 19.4%) treatment arms. The overall response was lower in the ≥ 65 years than the < 65 years subgroup in the isavuconazole (23.7% vs 39.0%) and voriconazole (32.0% vs 37.5%) arms. The safety and efficacy of isavuconazole were better in patients < 65 versus ≥ 65 years, and the safety profile was more favorable than that of voriconazole in both subgroups.Clinicaltrials.gov identifier NCT00634049 and NCT00412893.

Breakthrough invasive fungal infection in patients with myeloid malignancy receiving posaconazole tablet prophylaxis: Clinical features, risk factors, and posaconazole profiles.

Posaconazole (PSC) delayed-release tablet prophylaxis is the standard of care for preventing invasive fungal infection (IFI) in patients with acute myeloid leukemia undergoing myelosuppressive chemotherapy. The clinical features, risk factors, and PSC profiles of breakthrough IFI (bIFI) in patients receiving PSC tablet prophylaxis were investigated. A single-center retrospective cohort study was conducted, including adult patients with myeloid malignancy who received prophylactic PSC tablets while undergoing chemotherapy from June 2016 to June 2021. Logistic regression analysis was used to identify risk factors for bIFI. A receiver operating characteristic curve was used to predict the relationship between PSC trough level at steady state and bIFI. A total of 434 patients with myeloid malignancy who received PSC tablets were screened. A total of 10 patients with bIFI were compared with 208 non-IFI patients. There were four proven and six probable IFI cases, nine due to Aspergillus, and one due to Fusarium species. The bIFI patients had higher in-hospital mortality (30.0%) than the non-IFI patients (1.9%; P < 0.001). History of allogeneic hematopoietic stem cell transplantation (odds ratio [OR] 6.27; 95% confidence interval [CI] 1.63-24.09), prolonged neutropenia ≥28 days (OR 4.33; 95% CI 1.20-15.70), and low plasma PSC concentration <0.7 µg/ml (OR 16.33; 95% CI 4.15-64.26) were risk factors for bIFI. The optimal cutoff value of plasma PSC concentration predicting bIFI was 0.765 µg/ml (sensitivity, 60.0%; specificity, 91.3%; area under the curve, 0.746). bIFI was not uncommon in patients with myeloid malignancy receiving PSC tablet prophylaxis and associated with poor outcomes. Therapeutic drug monitoring may still be necessary, even in patients receiving PSC tablets.

Invasive fungal infections increase mortality in acute myeloid leukemia patients. This study investigated breakthrough invasive fungal infection cases in patients receiving posaconazole tablet prophylaxis. Our results will contribute to improving the outcome of patients with myeloid malignancy.

Physicians' knowledge of invasive fungal disease in China.

BACKGROUND: Invasive fungal disease (IFD) is associated with high morbidity and mortality. Data are lacking regarding physicians' perspectives on the diagnosis and management of IFD in China. OBJECTIVES: To evaluate physicians' perspectives on the diagnosis and management of IFD. METHODS: Based on current guidelines, a questionnaire was designed and administered to 294 physicians working in haematology departments, intensive care units, respiratory departments and infectious diseases departments in 18 hospitals in China. RESULTS: The total score and subsection scores for invasive candidiasis, invasive aspergillosis (IA), cryptococcosis and invasive mucormycosis (IM) were 72.0 ± 12.2 (maximum = 100), 11.1 ± 2.7 (maximum = 19), 43.0 ± 7.8 (maximum = 57), 8.1 ± 2.0 (maximum = 11) and 9.8 ± 2.3 (maximum = 13), respectively. Although the perspectives of the Chinese physicians were in good overall agreement with guideline recommendations, some knowledge gaps were identified. Specific areas in which the physicians' perspectives and guideline recommendations differed included use of the ß-D-glucan test to facilitate the diagnosis of IFD, relative utility of the serum galactomannan test and bronchoalveolar lavage fluid galactomannan test in patients with agranulocytosis, use of imaging in the diagnosis of mucormycosis, risk factors for mucormycosis, indications for initiating antifungal therapy in patients with haematological malignancies, when to start empirical therapy in mechanically ventilated patients, first-line drugs for mucormycosis and treatment courses for IA and IM. CONCLUSION: This study highlights the main areas that could be targeted by training programs to improve the knowledge of physicians treating patients with IFD in China.

Diagnosis of invasive respiratory mycoses in the immunocompromised host.

PURPOSE OF REVIEW: The burden of invasive fungal infection is increasing worldwide, largely due to a growing population at-risk. Most serious human fungal pathogens enter the host via the respiratory tract. Early identification and treatment of invasive fungal respiratory infections (IFRIs) in the immunocompromised host saves lives. However, their accurate diagnosis is a difficult challenge for clinicians and mortality remains high. RECENT FINDINGS: This article reviews IFRIs, focussing on host susceptibility factors, clinical presentation, and mycological diagnosis. Several new diagnostic tools are coming of age including molecular diagnostics and point-of-care antigen tests. As diagnosis of IFRI relies heavily on invasive procedures like bronchoalveolar lavage and lung biopsy, several novel noninvasive diagnostic techniques are in development, such as metagenomics, 'volatilomics' and advanced imaging technologies. SUMMARY: Where IFRI cannot be proven, clinicians must employ a 'weights-of-evidence' approach to evaluate host factors, clinical and mycological data. Implementation studies are needed to understand how new diagnostic tools can be best applied within clinical pathways. Differentiating invasive infection from colonization and identifying antifungal resistance remain key challenges. As our diagnostic arsenal expands, centralized clinical mycology laboratories and efforts to ensure access to new diagnostics in low-resource settings will become increasingly important.

Microbial and clinical epidemiology of invasive fungal rhinosinusitis in hospitalized COVID-19 patients, the divergent causative agents.

Since COVID-19 spread worldwide, invasive fungal rhinosinusitis (IFRS) has emerged in immunocompromised patients as a new clinical challenge. In this study, clinical specimens of 89 COVID-19 patients who presented clinical and radiological evidence suggestive of IFRS were examined by direct microscopy, histopathology, and culture, and the isolated colonies were identified through DNA sequence analysis. Fungal elements were microscopically observed in 84.27% of the patients. Males (53.9%) and patients over 40 (95.5%) were more commonly affected than others. Headache (94.4%) and retro-orbital pain (87.6%) were the most common symptoms, followed by ptosis/proptosis/eyelid swelling (52.8%), and 74 patients underwent surgery and debridement. The most common predisposing factors were steroid therapy (n = 83, 93.3%), diabetes mellitus (n = 63, 70.8%), and hypertension (n = 42, 47.2%). The culture was positive for 60.67% of the confirmed cases, and Mucorales were the most prevalent (48.14%) causative fungal agents. Different species of Aspergillus (29.63%) and Fusarium (3.7%) and a mix of two filamentous fungi (16.67%) were other causative agents. For 21 patients, no growth was seen in culture despite a positive result on microscopic examinations. In PCR-sequencing of 53 isolates, divergent fungal taxons, including 8 genera and 17 species, were identified as followed: Rhizopus oryzae (n = 22), Aspergillus flavus (n = 10), A. fumigatus (n = 4), A. niger (n = 3), R. microsporus (n = 2), Mucor circinelloides, Lichtheimia ramosa, Apophysomyces variabilis, A. tubingensis, A. alliaceus, A. nidulans, A. calidoustus, Fusarium fujikuroi/proliferatum, F. oxysporum, F. solani, Lomentospora prolificans, and Candida albicans (each n = 1). In conclusion, a diverse set of species involved in COVID-19-associated IFRS was observed in this study. Our data encourage specialist physicians to consider the possibility of involving various species in IFRS in immunocompromised and COVID-19 patients. In light of utilizing molecular identification approaches, the current knowledge of microbial epidemiology of invasive fungal infections, especially IFRS, may change dramatically.

Invasive fungal rhinosinusitis (IFRS) may infect people with diabetes, cancer, or COVID-19. In this study, various types of fungi were identified from COVID-19-associated-IFRS, encouraging physicians to consider specific treatments.

Health economic analysis of patients treated with isavuconazole in a German comprehensive cancer centre.

BACKGROUND: Invasive fungal diseases (IFD) are life-threatening and demand timely and appropriate treatment. Research showed that isavuconazole treatment positively affects clinical outcome and length of hospital stay (LOS). OBJECTIVES: The aim of this study was to assess the hospital costs of patients diagnosed with IFD and treated with isavuconazole using real-world data from a German cancer centre. PATIENTS/METHODS: Data and LOS collected from Jan-2016 to Jun-2021 at Department I of Internal Medicine, University Hospital Cologne were retrieved. Case-related resources consumed during the hospital stay across isavuconazole routes of administration (oral, parenteral, and mixed administration) were identified, quantified, valued and compared via a cost analysis that adopted the healthcare payer perspective. RESULTS: In total, 101 cases with isavuconazole treatment were identified (oral: n = 22, 21.8%; parenteral: n = 59, 58.4%; mixed: n = 20, 19.8%). Median total LOS was greater in the mixed group (46.5 days; p = .009). Median ICU LOS and ventilation duration were both longest in the parenteral-only group (16 days, p = .008; 224 h, p = .003). Invasive aspergillosis was the most frequent isavuconazole indication (n = 86, 85.2%). Average hospital costs were highest in the mixed group (€ 101,226). The median overall costs of cases treated with isavuconazole was € 52,050. CONCLUSIONS: Treating IFD is resource intensive, often requires intensive care and implies high rates of in-hospital mortality. Our study emphasises the high hospital treatment costs and thus the need for reimbursement systems to enable live-saving costly treatments.

Improving awareness, diagnosis and management of invasive fungal infections in Ghana: establishment of the Ghana Medical Mycology Society.

Invasive fungal infections (IFIs) and medical mycology receive little attention in Ghana. However, the present evolution of biomarker assays for IFIs, offers an opportunity for an increased access to fungal laboratory testing in resource-limited settings, and probably make a case for availability of essential antifungal agents. Using surveys and personal communications, the state of medical mycology and IFI in Ghana were highlighted. Inadequate awareness and insufficient access to fungal diagnostics and therapeutics were identified as the key challenges, the establishment of the Ghana Medical Mycology Society was discussed, and recommendations were made to improve the status quo.

Invasive fungal infections (IFIs) receive little attention in Ghana, despite its growing relevance globally. Using surveys and personal communications, the main challenges were identified, and the formation of the Ghana Medical Mycology Society was discussed as a tool to improve the status quo.

Infección fúngica invasiva por Saprochaete capitata en un niño con aplasia medular / Invasive fungal infection by Saprochaete capitata in a child with bone marrow aplasia

RESUMEN Saprochaete capitata es una causa rara de infección fúngica invasiva en pacientes inmunocomprometidos con alta mortalidad y resistencia antifúngica. Presentamos el caso de un niño de cinco años con diagnóstico de aplasia medular, sometido a trasplante de progenitores hematopoyéticos (TPH), que cursó con neutropenia febril persistente, dolor abdominal intenso, aparición de lesiones maculopapulares en piel y deterioro de la función renal. Se identificó la presencia de S. capitata, en hemocultivos transcatéter venoso central. Esta infección fúngica invasiva resulta ser rara, pero emergente y potencialmente mortal, en pacientes con neutropenia febril persistente y uso prolongado de dispositivos invasivos intravasculares como catéter venoso central.

ABSTRACT Saprochaete capitata is a rare cause of invasive fungal infection in immunocompromised patients with high mortality and antifungal resistance. We present the case of a 5-year-old boy with bone marrow aplasia, who underwent hematopoietic stem cell transplantation (HSCT) and presented persistent febrile neutropenia, abdominal pain, appearance of maculopapular lesions on the skin, and impaired renal function. The presence of S. capitata was identified by blood culture from a central venous catheter. This invasive fungal infection is rare but emergent and life-threatening, especially in immunocompromised patients with persistent febrile neutropenia and prolonged use of invasive devices such as central venous catheters.

When and how do we stop antifungal treatment for an invasive mould infection in allogeneic haematopoietic cell transplant recipients?

BACKGROUND: Limited data exist to describe end-of-treatment (EOT) parameters of antifungal therapy for invasive mould infections (IMI). METHODS: In a 10-year cohort of consecutive adult allogeneic haematopoietic cell transplant recipients with proven/probable IMI, we describe treatment duration and patient profile at EOT. RESULTS: There were 61 patients with 66 proven/probable IMI identified: 47/66 (71%) invasive aspergillosis (IA), 11/66 (17%) mucormycosis, and 8/66 (12%) other-IMI. Excluding 5 (8%) patients lost to follow-up, treatment was prematurely discontinued due to death or palliative care in 29/56 (51.8%) patients. Antifungal treatment was completed in 27 (48.2%) patients, for a median duration of 280 days (IQR: 110, 809): 258 (IQR: 110, 1905) and 307.5 (99, 809) days in IA and non-IA IMI, respectively. Treatment was continued after 90 and 180 days in 43/56 (76.8%) and 30/56 (53.6%) patients, respectively. At EOT, most patients were not neutropenic (ANC: 2.12 G/L, IQR: 0.04, 5.3), with CD4+ counts at 99 cells/µl (IQR: 0, 759) and immunoglobulins at 5.6 g/L (IQR: 2.3, 10.6). Most patients (16/27, 59.3%) were not receiving steroids at EOT, while 14/27 (53.9%) were on another type of immunosuppression. Amongst 15 patients with imaging at EOT, 12 (80%) had complete/partial radiologic response. Any chart documentation or an infectious disease consultation on treatment discontinuation was observed in 12/56 (21%) and 11/56 (20%) patients, respectively. CONCLUSIONS: Long treatment courses are observed in patients with IMI, due to prolonged immunosuppression. Although immune reconstitution and radiological response were frequently observed at EOT, consistent documentation of treatment discontinuation based on well-defined parameters is lacking.

Future Fungal Fighters in Dermatology: Novel Antifungal Drug Pipeline.

Over the last decade, major advances in antifungal drug development have occurred. Novel drugs in the pipeline include ME1111, MAT2203, rezafungin, ibrexafungerp, olorofim, fosmanogepix, MGCD290, VT-1161, NP213, T-2307, aureobasidin A, and nikkomycin Z. While most of these “future fungal fighters” have been developed to address invasive fungal infections (IFI), there is potential for dermatologists to benefit as these drugs may be adapted for superficial infections. Here, we review the major developments in novel antifungals and examine the ways in which dermatologists may gain from these recent innovations. J Drugs Dermatol. 2022;21(5):496-501. doi:10.36849/JDD.6373.