Retrospective Cohort Analysis of Liposomal Amphotericin B Nephrotoxicity in Patients with Hematological Malignancies

Toxicity of a novel antifungal agent (ATB1651 gel) in Yucatan minipigs (Sus scrofa) following 4 weeks of daily dermal administration

ATB1651 gel is an antifungal drug candidate that enhances antifungal activity through substitution of several aryl rings, alkyl chains, and methyl groups. To ensure safety of use of ATB1651 gel, assessment of its potentially toxic side effects is necessary. In this study, we examined the repeated-dose toxicity of ATB1651 gel to Yucatan minipigs (Sus scrofa) in accordance with the Good Laboratory Practice guidelines. Five doses of ATB1651 gel (0%, 0.2%, 0.5%, 1.0%, 3.0%) were administered dermally to the left and right flanks of 38 minipigs daily for 4 weeks. Mortality, clinical symptoms, dermal scores, body weights, and physiological, biochemical, pathological, and toxicokinetic analyses were performed after the treatment period. No systemic toxicological damage was observed in either male or female minipigs regardless of dose; however, dermal application of ATB1651 gel caused some skin alterations at the application sites. Specifically, erythema and eschar formation, edema, and scabs or raise spots were observed at the application site(s) in males in the 3.0% ATB1651 gel treatment group and in females at ATB1651 gel concentrations ≥ 1.0%, with dermal scores ranging from grade 1 to 2. Additionally, histopathological assay indicated infiltration of different types of inflammatory cells and the presence of pustule/crust at the application site(s) in both males and females at ATB1651 gel concentrations ≥ 0.5%. However, these changes were reversible after a 2-week recovery period and were considered a local irritation effect of ATB1651 gel. The no-observed-adverse-effect level of ATB1651 gel was 3.0% with regard to topical and systemic toxicity in both male and female minipigs. Collectively, our results imply that ATB1651 gel is a safe candidate for clinical development as an antifungal drug with a wide therapeutic window.

Antimicrobials in patients with hematologic malignancies and recipients of hematopoietic cell transplantation and other cellular therapies

BACKGROUND

Appropriate use of antimicrobials for hematologic malignancy, hematopoietic stem cell transplant recipients, and other cellular therapies is vital, with infection causing significant morbidity and mortality in this unique population of immunocompromised hosts. However, often in this population the choice and management of antimicrobial therapy is complex. When selecting an antimicrobial agent, key considerations include the need for dose adjustments due to renal or hepatic impairment, managing drug interactions, the potential for additive drug toxicity among those receiving polypharmacy and therapeutic drug monitoring. Other factors include leveraging pharmacodynamic principles to enable optimization of directed therapy against challenging pathogens, as well as judicious use of antimicrobials to limit drug resistance and adverse drug reactions.

SUMMARY

This review summarizes the clinical considerations for commonly used antimicrobials in this setting, including antibacterial, antiviral, and antifungal agents.

Systemic Antifungal Therapy for Invasive Pulmonary Infections

Antifungal therapy for pulmonary fungal diseases is in a state of flux. Amphotericin B, the time-honored standard of care for many years, has been replaced by agents demonstrating superior efficacy and safety, including extended-spectrum triazoles and liposomal amphotericin B. Voriconazole, which became the treatment of choice for most pulmonary mold diseases, has been compared with posaconazole and itraconazole, both of which have shown clinical efficacy similar to that of voriconazole, with fewer adverse events. With the worldwide expansion of azole-resistant Aspergillus fumigatus and infections with intrinsically resistant non-Aspergillus molds, the need for newer antifungals with novel mechanisms of action becomes ever more pressing.

Liposomal amphotericin B—the future

Advances in medicine have led to a growing number of people with compromised or suppressed immune systems who are susceptible to invasive fungal infections. In particular, severe fungal infections are becoming increasingly common in ICUs, affecting people within and outside of traditional risk groups alike. This is exemplified by the emergence of severe viral pneumonia as a significant risk factor for invasive pulmonary aspergillosis, and the recognition of influenza-associated pulmonary aspergillosis and, more recently, COVID-19-associated pulmonary aspergillosis.

The treatment landscape for haematological malignancies has changed considerably in recent years, and some recently introduced targeted agents, such as ibrutinib, are increasing the risk of invasive fungal infections. Consideration must also be given to the risk of drug–drug interactions between mould-active azoles and small-molecule kinase inhibitors.

At the same time, infections caused by rare moulds and yeasts are increasing, and diagnosis continues to be challenging. There is growing concern about azole resistance among both moulds and yeasts, mandating continuous surveillance and personalized treatment strategies.

It is anticipated that the epidemiology of fungal infections will continue to change and that new populations will be at risk. Early diagnosis and appropriate treatment remain the most important predictors of survival, and broad-spectrum antifungal agents will become increasingly important. Liposomal amphotericin B will remain an essential therapeutic agent in the armamentarium needed to manage future challenges, given its broad antifungal spectrum, low level of acquired resistance and limited potential for drug–drug interactions.

Adjunctive use of saturated solution of potassium iodide (SSKI) with liposomal amphotericin B (L-AMB) in mucormycosis achieves favorable response, shortened dose and duration of amphotericin: A retrospective study from a COVID-19 tertiary care center

Purpose

Second wave of COVID-19 pandemic was associated with an unprecedented rise in cases of mucormycosis, treatment of which has been challenging owing to the availability and side effects associated with amphotericin.

Methods

All patients presenting with rhino-orbital cerebral mucormycosis (ROCM) following COVID-19 infection between April 2021 to June 2021 were included in this retrospective interventional study. Primary objective was to assess the clinical response with combination of intravenous liposomal amphotericin B (4–5 mg/kg/day) and saturated solution of potassium iodide (SSKI) given orally along with surgical debridement.

Results

Twenty-five patients of ROCM were treated with the regimen. Mean age and fasting blood sugar levels were 53.48 years and 239.64 mg/dL respectively. All patients had history of intake of steroids with a mean daily dose of 86.39 mg of prednisolone equivalent. 88% of patients had a “proven” diagnosis of mucormycosis. Cultures were positive in 52% of patients with Rhizopus arrhizus as the predominant species. The mean daily dose of amphotericin received was 268 mg/day with a mean duration of 9.52 days. Mean daily dose of SSKI was 2.57 g. 21 patients (84%) had stabilization of disease at week 8 and achieved cure at the end of treatment whereas the mortality rate was 16%. Factors that significantly affected outcome were eye and central nervous system (CNS) involvement on presentation.

Conclusion

SSKI, with its remarkably low cost and safety profile, makes it a potential adjuvant drug that may help achieve the twin benefits of shortened duration and dose of LAMB.

Targeted Delivery of Antifungal Liposomes to Rhizopus delemar

Mucormycosis (a.k.a. zygomycosis) is an often-life-threatening disease caused by fungi from the ancient fungal division Mucoromycota. Globally, there are nearly a million people with the disease. Rhizopus spp., and R. delemar (R. oryzae, R. arrhizus) in particular, are responsible for most of the diagnosed cases. Pulmonary, rhino-orbito-cerebral, and invasive mucormycosis are most effectively treated with amphotericin B (AmB) and particularly with liposomal formulations (e.g., AmBisome^®). However, even after antifungal therapy, there is still a 50% mortality rate. Hence, there is a critical need to improve therapeutics for mucormycosis. Targeting AmB-loaded liposomes (AmB-LLs) with the pathogen receptor Dectin-1 (DEC1-AmB-LLs) to the beta-glucans expressed on the surface of Aspergillus fumigatus and Candida albicans lowers the effective dose required to kill cells relative to untargeted AmB-LLs. Because Dectin-1 is an immune receptor for R. delemar infections and may bind it directly, we explored the Dectin-1-mediated delivery of liposomal AmB to R. delemar. DEC1-AmB-LLs bound 100- to 1000-fold more efficiently to the exopolysaccharide matrix of R. delemar germlings and mature hyphae relative to AmB-LLs. DEC1-AmB-LLs delivering sub-micromolar concentrations of AmB were an order of magnitude more efficient at inhibiting and/or killing R. delemar than AmB-LLs. Targeted antifungal drug-loaded liposomes have the potential to improve the treatment of mucormycosis.

Observational cross-sectional case study of toxicities of antifungal drugs

INTRODUCTION

In this study we examined the toxicities, including poisoning and overdoses, with polyene, azole, flucytosine and echinocandin antifungals reported to the National Poison Center.

METHODS

An observational cross-sectional study on antifungals was performed based on reports between 1995 and 2016 to Tox Info Suisse. Patient demographic and clinical characteristics were summarized among all reported calls, stratified by age group. In secondary analyses, we evaluated cases with clinical follow-up information.

RESULTS

In total, 149 cases were reported to the National Poison Centre within the study period of which 49 (32.9%) were male and 91 (61.1%) were female. 95 (63.8%) were adults and 54 (36.2%) were children (age ≤ 16). The most frequently reported drug class were the azoles (n=136, 91.3%). In 31 cases (21%) reported by the treating physicians, further clinical follow-up information was available. Nearly half of these patients were asymptomatic (n=15, 48%). Among those with symptoms, in 11 (33%) patients, the symptoms of toxicity were categorized with a strong causality to the respective antifungal. Clinical findings caused by the triazoles were effects in the gastrointestinal tract, hallucinations and predilirium state. The clinical findings caused by the polyenes were mostly minor symptoms with infusion-related effects or hypokalemia. In 6 (54.6%) out of 11 cases the severity was categorized as minor and for 5 (45.5%) as moderate, respectively.

CONCLUSION

Despite high administered doses, no severe or fatal cases occurred within the study period. Although various toxicities can occur with antifungal administration and overdoses, they showed a favorable safety profile.

[Clinical safety of liposomal amphotericin B]

This article reviews the safety profile of liposomal amphotericin B, emphasizing the renal toxicity; the risk factors for its presentation, incidence, severity, and potential reversibility are expounded.

Lower vancomycin trough levels in adults undergoing unrelated cord blood transplantation

Vancomycin (VCM) is frequently used for neutropenic patients undergoing cord blood transplantation (CBT). We retrospectively examined the relationship between VCM trough levels and the efficacy and toxicity in 122 adult patients undergoing CBT in our institute. The median initial dose of VCM based on body weight was 9.1 mg/kg/dose (range, 6.0-22.6 mg/kg/dose). The median initial trough level of VCM for all patients was 4.50 µg/mL (range, 1.20-24.05 µg/mL), at a median of 3 days (range, 2-6 days) after VCM administration. The cumulative incidence of acute kidney injury (AKI) was 19% at 30 days after VCM administration. A higher median trough level of VCM during the first 7 days was significantly associated with the development of AKI in the multivariate analysis (Hazard ratio: 1.28, p = .026). These data suggest that a lower VCM trough level may be safe in adult patients undergoing CBT under therapy with nephrotoxic drugs.

Changing the terminology from kidney replacement therapy to kidney support therapy

Kidney replacement therapy (KRT) is a common supportive treatment for renal dysfunction, especially acute kidney injury. However, critically ill or immunosuppressed patients with renal dysfunction often have dysfunction in other organs as well. To improve patient outcomes, clinicians began to initiate kidney replacement therapy in situations where nonrenal conditions may lead to acute kidney injury, such as septic shock, hematopoietic stem cell transplantation, veno-occlusive renal disease, cardiopulmonary bypass, chemotherapy, tumor lysis syndrome, hyperammonemia, and various others. In this review, we discuss the use of various modes of kidney replacement therapy in treating renal and nonrenal complications to illustrate why kidney support therapy is a more appropriate terminology than kidney replacement therapy.

Successful treatment of Aspergillus fumigatus sternal osteomyelitis with isavuconazole in a heart transplant recipient

A 65-year-old man was diagnosed with an invasive Aspergillus fumigatus infection with sternal osteomyelitis 4 months after heart transplantation. Unfortunately, after 8 weeks patient developed severe cutaneous and neurological toxicities induced by voriconazole leading to drug discontinuation. Therefore, isavuconazole was chosen as second-line therapy. The patient presented a favorable outcome and tolerance was excellent after ten months monotherapy. Here, we report for a first time, an successful isavuconazole-based treatment of sternal osteomyelitis aspergillosis in a cardiac recipient.

Global guideline for the diagnosis and management of mucormycosis: an initiative of the European Confederation of Medical Mycology in cooperation with the Mycoses Study Group Education and Research Consortium

Mucormycosis is a difficult to diagnose rare disease with high morbidity and mortality. Diagnosis is often delayed, and disease tends to progress rapidly. Urgent surgical and medical intervention is lifesaving. Guidance on the complex multidisciplinary management has potential to improve prognosis, but approaches differ between health-care settings. From January, 2018, authors from 33 countries in all United Nations regions analysed the published evidence on mucormycosis management and provided consensus recommendations addressing differences between the regions of the world as part of the "One World One Guideline" initiative of the European Confederation of Medical Mycology (ECMM). Diagnostic management does not differ greatly between world regions. Upon suspicion of mucormycosis appropriate imaging is strongly recommended to document extent of disease and is followed by strongly recommended surgical intervention. First-line treatment with high-dose liposomal amphotericin B is strongly recommended, while intravenous isavuconazole and intravenous or delayed release tablet posaconazole are recommended with moderate strength. Both triazoles are strongly recommended salvage treatments. Amphotericin B deoxycholate is recommended against, because of substantial toxicity, but may be the only option in resource limited settings. Management of mucormycosis depends on recognising disease patterns and on early diagnosis. Limited availability of contemporary treatments burdens patients in low and middle income settings. Areas of uncertainty were identified and future research directions specified.

Effect of serum concentration and concomitant drugs on vancomycin-induced acute kidney injury in haematologic patients: a single-centre retrospective study

PURPOSE

Appropriate use of vancomycin (VCM) is important in preventing acute kidney injury (AKI). Because of the high frequency of VCM use for febrile neutropenia and concomitant use of other nephrotoxic drugs, haematologic patients have a different nephrotoxic background compared with patients with other diseases. Therefore, it is unclear whether the risk factors of VCM-induced AKI identified in other patient groups are also applicable to haematologic patients. Herein, we performed a single-centre retrospective analysis to identify the factors associated with VCM-induced AKI in haematologic patients.

METHODS

We retrospectively analysed 150 haematologic patients to whom VCM was administered between April 2010 and March 2018 at Tokushima University Hospital. VCM-induced AKI was defined according to Kidney Disease Improving Global Outcomes (KDIGO) criteria. Multivariate logistic regression analyses were performed to identify risk factors for VCM-induced AKI.

RESULTS

Seventeen patients had VCM-induced AKI. Multivariate analysis revealed that the risk factors of VCM-induced AKI were an initial VCM trough concentration of > 15 mg/L and concomitant use of tazobactam/piperacillin (TAZ/PIPC) and liposomal amphotericin B (L-AMB). Patients with an initial VCM trough concentration of < 10 mg/L showed significantly lower efficacy in febrile neutropenia. Interestingly, concomitant L-AMB use increased the incidence of VCM-induced AKI in a VCM concentration-dependent manner, whereas concomitant TAZ/PIPC increased the incidence in a VCM concentration-independent manner.

CONCLUSIONS

The optimal initial VCM trough concentration was 10-15 mg/L in haematologic patients, considering safety and effectiveness. There were differences in the effect of VCM-induced AKI between nephrotoxic drugs.

Two cases of Osteoarticular Mucor menace: A diagnostic and management conundrum

Mucormycosis is an uncommon aggressive fungal infection usually seen in immunocompromised hosts or patients with burns and trauma. The common presentations include rhino-orbital-cerebral and pulmonary involvement. Osteoarticular involvement is a rare presentation of this disease. We present two cases of osteoarticular mucormycosis of pelvis and long bones of the lower limb, one in a patient with burn injury and other one in a patient with chronic granulomatous disease, hitherto a rarely reported association. Delayed diagnosis in a setting where tuberculosis is a common cause of chronic osteomyelitis, challenges in medical and surgical management of these patients are discussed in this report.

Efficacy and Safety of Low-Dose Liposomal Amphotericin B in Adult Patients Undergoing Unrelated Cord Blood Transplantation

Liposomal amphotericin B (L-AMB) is widely used for empirical or preemptive therapy and treatment of invasive fungal infections after cord blood transplantation (CBT). We retrospectively examined the efficacy and safety of low-dose L-AMB in 48 adult patients who underwent CBT between 2006 and 2017 in our institute. Within the entire cohort, 42 patients (88%) received L-AMB as empirical or preemptive therapy. The median daily dose of L-AMB and the median cumulative dose of L-AMB were 1.20 mg/kg/day (range, 0.62 to 2.60 mg/kg/day) and 30.6 mg/kg (range, 0.7 to 241.5 mg/kg), respectively. The median duration of L-AMB administration was 21.5 days (range, 1 to 313 days). A documented breakthrough fungal infection occurred in 1 patient during L-AMB treatment, and 43 patients (90%) survived for at least 7 days after the end of L-AMB treatment. Grade 3 or higher hypokalemia and hepatotoxicity were frequently observed during L-AMB treatment. However, no patient developed an increase in serum creatinine levels of grade 3 or higher. In univariate analyses using a logistic regression model, a duration of L-AMB treatment of more than 21 days and a cumulative dose of L-AMB of more than 30 mg/kg were significantly associated with nephrotoxicity and grade 3 hypokalemia. These data suggest that low-dose L-AMB may be safe and effective in adult patients undergoing CBT.