Rivera, Christina G.

Abstract Background Pharmacokinetics of beta-lactams vary widely in neonatal and pediatric patients due to developmental biology and critical illness. Cefepime (FEP), meropenem (MEM), and piperacillin/tazobactam (TZP) are highly susceptible to pharmacokinetic changes as hydrophilic, small molecules with renal clearance. Subtherapeutic levels are associated with clinical and microbiologic failure, and supratherapeutic levels associated with toxicity. Beta-lactam therapeutic drug monitoring (TDM) may optimize the effectiveness and safety of these agents. The purpose of this investigation is to describe the % of pediatric and neonatal patients with beta-lactam serum levels within target range. Methods In August 2023, TDM launched at the Mayo Clinic Children’s Center for select patients treated with FEP, MEM, or TZP with expected durations ≥ 48 hours, or who were on kidney replacement therapy (KRT), extracorporeal membrane oxygenation (ECMO), weighed > 120 kg, had a BMI > 95th percentile, or at the discretion of pediatric ID team. Validated drug assays were performed daily, Monday through Friday. A two-level sampling strategy was preferred with a peak 1 hour after the end of the infusion and a trough 30 minutes before the next dose. Empiric trough target ranges were set at FEP 8-50 mg/L, MEM 2-30 mg/L, and piperacillin 16-150 mg/L. These target ranges were adjusted with confirmed microbiology to a time above the minimum inhibitory concentration of the organism for 100% of the dosing interval (100%T > MIC). Results From August 2023 to April 2024, 74 episodes of TDM were performed on 45 patients. Thirty-seven (82%) patients were in an intensive care unit (ICU) at the time of TDM, 8/45 (22%) of whom were in the neonatal ICU. Target range was achieved in 67% of patients on FEP, 50% on MEM, and 52% on TZP. Median (IQR) trough values were 22.1 (8.6, 44.2) mg/L for FEP, 0.6 (0, 4.1) mg/L for MEM, and 15.5 (3.8, 27.1) mg/L for TZP. Seven levels were above target for FEP and 0 for MEM and TZP. Seven levels were below target for FEP, 4 for MEM, and 11 for TZP. Conclusion Implementation of a TDM program for FEP, MEM and TZP in pediatric and neonatal patients revealed drug levels frequently outside target range. TDM may facilitate dose individualization to optimize medication efficacy and minimize toxicity. Disclosures Raymond Stetson, MD, MS, Moderna: Grant/Research Support Christina G. Rivera (O'Connor), Pharm.D, Gilead Sciences: Board Member Erin F. Barreto, PharmD, MSc, Baxter Health: Advisor/Consultant|Wolters Kluwer: Advisor/Consultant

Abstract Background With progressive understanding of the natural history of COVID-19 and accumulation of knowledge on clinical management, treatment guidelines recommended several options including remdesivir (RDV), a broad-spectrum antiviral. Given the evolving nature of COVID-19, it is critical to capture the totality of scientific evidence to inform clinical decision making. We conducted a systematic literature review (SLR) to summarize the mortality endpoint for RDV among hospitalized adults throughout COVID-19 eras and contrasted with evidence informing treatment recommendations in clinical guidelines. Methods We systematically searched MEDLINE, Embase and Cochrane Library databases for interventional and observational studies examining RDV efficacy. Clinical trial registries, Cochrane COVID-19 Study Register, and conference abstracts were hand-searched (Fig1). Case reports and case studies were excluded. A review of most recent RDV recommendations across guidelines was conducted. Results From Dec ’19 to Dec ’22, 123 relevant publications were identified. In ’23, the evidence grew significantly, with 70 new publications. In total, 193 publications were evaluated, and 122 unique studies were included. While early randomized clinical trials (RCT) and small sample size observational studies did not universally demonstrate a significant difference in mortality in all severity groups of RDV-treated patients, real-world studies with larger sample sizes showed a significant impact across disease severity levels, regardless of COVID-19 era (Table1). Guideline recommendations for COVID-19 treatment with RDV are based on early RCTs (Table2) and most have not been updated (Fig2). Conclusion Our comprehensive evaluation of scientific literature indicates that evidence of RDV impact on mortality in hospitalized COVID-19 patients continued to grow and cover full range of disease severity. Guideline recommendations have not evolved in parallel which may explain differing recommendations in certain subgroups (e.g. IMV/ECMO). To assure that providers in the hospital setting are aware of and deploy evidence-based optimal care for patients with COVID-19, recommendations should rely on current evidence, including real-world data. Disclosures Essy Mozaffari, PharmD, MPH, MBA, Gilead Sciences, Inc.: Employee|Gilead Sciences, Inc.: Stocks/Bonds (Public Company) Michele Bartoletti, MD, PhD, Advan pharma: Advisor/Consultant|Advan pharma: Honoraria|Biomereux: Honoraria|Gilead: Advisor/Consultant|Gilead: Honoraria|Infectopharma: Advisor/Consultant|Msd: Advisor/Consultant|Msd: Grant/Research Support|Msd: Honoraria|Pfizer: Honoraria Alpesh N. Amin, MD, MBA, Alexion: Advisor/Consultant|Aseptiscope: Advisor/Consultant|AstraZeneca: Advisor/Consultant|Bayer: Advisor/Consultant|Dexcom: Advisor/Consultant|Eli Lilly: Advisor/Consultant|Ferring: Advisor/Consultant|Gilead: Advisor/Consultant|GSK: Advisor/Consultant|Heartrite: Advisor/Consultant|Nova Nordisk: Advisor/Consultant|Pfizer: Advisor/Consultant|Renibus: Advisor/Consultant|Reprieve: Advisor/Consultant|Salix: Advisor/Consultant|Seres: Advisor/Consultant|Spero: Advisor/Consultant Yohei Doi, MD, PhD, bioMerieux: Lecture fees|Entasis: Grant/Research Support|Fujifilm: Advisor/Consultant|Gilead Sciences: Advisor/Consultant|GSK: Advisor/Consultant|KANTO CHEMICAL CO.,INC.: Grant/Research Support|KANTO CHEMICAL CO.,INC.: Patent for genotyping kit|MeijiSeika Pharma: Advisor/Consultant|Moderna: Advisor/Consultant|MSD: Lecture fees|Pfizer: Advisor/Consultant|Shionogi & Co., Ltd.: Grant/Research Support|Shionogi & Co., Ltd.: Lecture fees Paul LOUBET, MD, PhD, Astrazeneca: Advisor/Consultant|Gilead: Advisor/Consultant|Moderna: Advisor/Consultant|Pfizer: Advisor/Consultant Christina G. Rivera (O'Connor), Pharm.D, Gilead Sciences: Board Member Michael Roshon, MD/PhD, MD/PhD, Gilead: Honoraria Thomas F. Oppelt, PharmD, BCPS, Gilead Sciences, Inc: I am an employee of Gilead Sciences, Inc|Gilead Sciences, Inc: Stocks/Bonds (Public Company) Mel Chiang, Ph.D., Gilead Sciences: I am an employee of Gilead Sciences|Gilead Sciences: Stocks/Bonds (Public Company)

Abstract Background Antibiograms are an important stewardship tool that can inform optimal empiric therapy; most antibiograms are hospital-wide. Unit-specific antibiogram data for unique patient populations including intensive care unit and pediatrics is robust; however, published experience with unit-specific antibiograms in the hematology-oncology (heme-onc) population is limited. These patients are unique because of the common use of antimicrobial prophylaxis, prolonged broad-spectrum antibiotics, and an immunocompromised state. We sought to examine the trends in antibiogram antimicrobial susceptibility over time. Methods This retrospective quality initiative included microbiology results (first isolates per patient per timeframe) from Mayo Clinic Rochester from 2012 to 2022. Eligible cultures were those identified as being obtained from one of 8 hematology, oncology, or bone marrow transplant inpatient units. Agar dilution susceptibility testing and Clinical and Laboratory Standards Institute (CLSI) breakpoints were used. Screening PCRs (eg, VRE PCR) were excluded. Culture and susceptibilities were identified by an EMR based report, compiled annually, and reported for two-year periods. Susceptibility rates were compared using the Chi-square test and Chi-square analysis for trends. Results There were 4 gram-negative and 5 gram-positive organism groups that met CLSI antibiogram criteria of ≥ 30 isolates and were included (tables 1-4). There were several significant differences in comparison to the hospital-wide antibiogram, with lower antibiotic susceptibility rates in the heme-onc units for multiple organisms, notably fluoroquinolones to E.coli and P. aeruginosa and several cephalosporins to Enterobacterales as well as penicillin and levofloxacin to Viridans group Streptococcus and vancomycin to E. faecium (tables 1&2). Over the period of 2012-2013 to 2021-2022, susceptibility rates remained stable among the heme-onc antibiogram, with few significant changes (tables 3&4). Conclusion Heme-onc antibiograms illustrated susceptibility rate differences compared to our hospital-wide antibiograms, particularly for antimicrobials used as prophylaxis. Through population-specific antibiograms, providers may be able to improve empiric antibiotic selection. Disclosures Christina G. Rivera (O'Connor), Pharm.D, Gilead Sciences: Board Member

Background: Patients with immunocompromising conditions, including those affected by hematologic malignancies, have a disproportionately high burden of morbidity and mortality related to COVID-19 compared to individuals without such conditions.Clinical practice guidelines (CPGs) recommend the use of remdesivir, a broad-spectrum antiviral, for treatment of mild to severeCOVID-19 in immunocompetent patients not requiring invasive mechanical ventilation. While the CPGs issued by the World Health Organization (WHO, 2023), National Institutes of Health (NIH, 2023) and the Infectious Diseases Society of America (IDSA, 2022) also recommended the use of remdesivir in patients with immunocompromising conditions at high risk for severe disease, there was limited evidence available at the time the recommendations were communicated, more than two years after the start of the pandemic. The European Conference on Infections in Leukemia (ECIL, 2022) guidelines include remdesivir among the treatment options for mild to moderate COVID-19 patients with hematologic malignancies. The lack of evidence for treatment efficacy and safety in patients with immunocompromising conditions, a population underrepresented or excluded from clinical trials, was mentioned in CPGs as a knowledge gap and as need for further research. In this research, we summarize the evidence for remdesivir efficacy and safety for treatment of COVID-19 in hospitalized patients with hematologic malignancies accumulated since the start of the pandemic. Methods: We systematically searched MEDLINE, Embase and Cochrane Library databases from January 2019 through December 2023 for interventional and observational studies examining remdesivir efficacy and safety. Case reports and case studies were excluded. A dual-reviewer approach was used for screening and data extraction. Results: Of the 7,654 references retrieved through the implementation of the extensive search strategy 59 (0.8%) reporting on patients with hematologic malignancies, unspecified cancers, or immunodeficiencies were identified and reviewed in full text. Only eight unique studies (8 of 59) were conducted in patients with hematologic malignancies, of which two reported remdesivir use in a minority of participants (n<5) and were excluded from further analyses. The remaining six studies, of which four were peer-reviewed original articles, one was a letter to editor and the last was a conference abstract, used a retrospective cohort design and reported efficacy outcomes for a combined total of 1,579 individuals across the studies. Three of the six studies were conducted during the pre-Omicron variant era (November 2021) while the remaining three started data collection in December 2021. There were four studies reporting number of deaths or the mortality rate, while a fifth study based on medical chart reviews of 313 patients in Israel found a significantly reduced risk of mortality among remdesivir recipients compared to patients not receiving remdesivir (OR: 0.297; 95% CI: 0.105, 0.834). In addition, a study including 466 patients from the Spanish Hematopoietic Stem Cell Transplantation and Cell Therapy Registry reported mortality among remdesivir treated group related to baseline disease progression, use of corticosteroids for COVID-19 therapy and the presence of coinfections while B-cell malignancy as underlying disease, severe COVID-19, late antiviral initiation (≥5 days after first positive PCR) and longer treatment duration (≥5 days) were factors significantly associated with prolonged viral shedding. The same Spanish study reported safety outcomes indicating that adverse events of grade 3 or above were rare, occurring in 0.5% of remdesivir treated patients. Conclusion: Despite the call for research to fill the knowledge gap signaled by the CPGs, our comprehensive systematic literature review identified only a few publications conducted since the start of the pandemic in patients with hematological malignancies. In the current endemic era, these patients are among the most at risk for severe outcomes and COVID-19 related hospitalizations. While the limited evidence suggests that remdesivir use can reduce mortality in patients with hematologic malignancies, additional research will be instrumental to inform development and updating of evidence-based recommendations to support and guide clinical management of oncology patients.

ABSTRACT A total of 1,925 Corynebacterium isolates were tested for antimicrobial susceptibility at the Mayo Clinic Microbiology laboratory (Rochester, Minnesota) from January 2012 to March 2023, with C. striatum (35.6%) and C. amycolatum (24.4%) identified as the predominant species. Species known to potentially carry diphtheria toxin were excluded. Common sources of isolation included skin and soft tissue (56.8%), bone and/or native joint synovial fluid (14.2%), urine (13.1%), sputum (6.1%), and blood (5.9%). For penicillin, susceptibility decreased from 47.5% (58 of 122) in 2012 to 20.6% (14 of 68) in 2023. Isolates also showed a decrease in susceptibility to erythromycin from 22.4% (26 of 116) in 2012 to 13.2% (9 of 68) in 2023. Susceptibility to trimethoprim-sulfamethoxazole averaged around 50% throughout the period. Notably, linezolid and vancomycin were universally effective in vitro against all species. The highest susceptibility rates among tested oral agents were to linezolid and doxycycline for non- C . striatum species. Daptomycin minimal inhibitory concentrations (MICs) of >256 µg/mL were observed for one C. amycolatum isolate, one C. tuberculostearicum isolate, and for seven C. striatum isolates, all from patients with prior daptomycin exposure. Daptomycin MICs of 2 µg/mL (nonsusceptible) were observed in one C. striatum isolate recovered from a daptomycin-naïve patient and in six C. jeikeium isolates, from both daptomycin-exposed and non-exposed patients. Significant variation in susceptibility profiles across different Corynebacterium species underscores the importance of performing antimicrobial susceptibility testing to guide effective treatment. Moreover, multidrug resistance observed in C. striatum poses substantial therapeutic challenges especially in patients requiring prolonged or chronic antibiotic suppression.

Abstract Outpatient parenteral antimicrobial therapy (OPAT) has become more common in infectious diseases practice settings. Similarly, OPAT-related publications have also increased. The objective of this article was to summarize clinically important OPAT-related publications from 2023. Eighty-one articles were found on initial search, with 52 meeting inclusion criteria. A survey containing the 19 articles that had at least 1 citation was sent to an email listserv of multidisciplinary clinicians with OPAT experience. This article summarizes the “top 10” 2023 OPAT articles from the survey results.

Abstract Objective This study aimed to conduct a scoping review of machine learning (ML) techniques in outpatient parenteral antimicrobial therapy (OPAT) for predicting adverse outcomes and to evaluate their validation, implementation and potential barriers to adoption. Materials and methods This scoping review included studies applying ML algorithms to adult OPAT patients, covering techniques from logistic regression to neural networks. Outcomes considered were medication intolerance, toxicity, catheter complications, hospital readmission and patient deterioration. A comprehensive search was conducted across databases including Cochrane Central, Cochrane Reviews, Embase, Ovid MEDLINE and Scopus, from 1 January 2000 to 1 January 2024. Results Thirty-two studies met the inclusion criteria, with the majority being single-centre experiences primarily from North America. Most studies focused on developing new ML models to predict outcomes such as hospital readmissions and medication-related complications. However, there was very little reporting on the performance characteristics of these models, such as specificity, sensitivity and C-statistics. There was a lack of multi-centre or cross-centre validation, limiting generalizability. Few studies advanced beyond traditional logistic regression models, and integration into clinical practice remains limited. Discussion ML shows promise for enhancing OPAT outcomes by predicting adverse events and enabling pre-emptive interventions. Despite this potential, significant gaps exist in development, validation and practical implementation. Barriers include the need for representative data sets and broadly applicable, validated models. Conclusion Future research should address these barriers to fully leverage ML’s potential in optimizing OPAT care and patient safety. Models must deliver timely, accurate and actionable insights to improve adverse event prediction and prevention in OPAT settings.

Abstract Beta-lactam antibiotics are widely used in the intensive care unit due to their favorable effectiveness and safety profiles. Beta-lactams given to patients with sepsis must be delivered as soon as possible after infection recognition (early), treat the suspected organism (appropriate), and be administered at a dose that eradicates the infection (adequate). Early and appropriate antibiotic delivery occurs in >90% of patients, but less than half of patients with sepsis achieve adequate antibiotic exposure. This project aimed to address this quality gap and improve beta-lactam adequacy using the Define, Measure, Analyze, Improve, and Control Lean Six Sigma quality improvement framework. A multidisciplinary steering committee was formed, which completed a stakeholder analysis to define the gap in practice. An Ishikawa cause and effect (Fishbone) diagram was used to identify the root causes and an impact/effort grid facilitated prioritization of interventions. An intervention that included bundled education with the use of therapeutic drug monitoring (TDM; i.e. drug-level testing) was projected to have the highest impact relative to the amount of effort and selected to address beta-lactam inadequacy in the critically ill. The education and TDM intervention were deployed through a Plan, Do, Study, Act cycle. In the 3 months after “go-live,” 54 episodes of beta-lactam TDM occurred in 41 unique intensive care unit patients. The primary quality metric of beta-lactam adequacy was achieved in 94% of individuals after the intervention. Ninety-four percent of clinicians gauged the education provided as sufficient. The primary counterbalance of antimicrobial days of therapy, a core antimicrobial stewardship metric, was unchanged over time (favorable result; P = .73). Application of the Define, Measure, Analyze, Improve, and Control Lean Six Sigma quality improvement framework effectively improved beta-lactam adequacy in critically ill patients. The approach taken in this quality improvement project is widely generalizable to other drugs, drug classes, or settings to increase the adequacy of drug exposure.

Abstract Nontuberculous mycobacteria (NTM) can cause a variety of infections, including serious pulmonary disease. Treatment encompasses polypharmacy, with a targeted regimen of 2–5 active medications, depending on site of infection, species, and clinical characteristics. Medications may include oral, intravenous, and inhalational routes. Medication acquisition can be challenging for numerous reasons, including investigational status, limited distribution models, and insurance prior authorization. Additionally, monitoring and managing adverse reactions and drug interactions is a unique skill set. While NTM is primarily medically managed, clinicians may not be familiar with the intricacies of medication selection, procurement, and monitoring. This review offers insights into the pharmacotherapeutic considerations of this highly complex disease state, including regimen design, medication acquisition, safety monitoring, relevant drug–drug interactions, and adverse drug reactions.

ABSTRACT The use of ceftriaxone, a highly protein-bound drug, in the setting of hypoalbuminemia may result in suboptimal drug exposure. Patients with obesity also exhibit higher absolute drug clearance. We aimed to evaluate the impact of hypoalbuminemia on clinical success among hospitalized adults with obesity who were treated with ceftriaxone. This retrospective review included adult inpatients with weight >100 kg or body mass index >40 kg/m 2 who received ceftriaxone 2 g intravenously every 12 hours for at least 72 hours. The primary outcome was clinical success, a composite of clinical cure and microbiologic cure. Secondary outcomes included clinical cure, microbiologic cure, length of stay, ICU length of stay, mortality, 30-day readmission, and adverse events. In all, 137 patients were included, 34 of whom had a serum albumin of ≤2.5 g/dL. In a propensity-score-weighted analysis, clinical success was significantly more common among those without hypoalbuminemia (91.2%) as compared to those with hypoalbuminemia (77.8%) ( P = 0.038). Death within 30 days (13.7% vs 0%, P < 0.001) and 30-day readmission (31.6% vs 12.0%, P = 0.008) were more common in the hypoalbuminemia group. In a univariate analysis, serum albumin and indication for ceftriaxone use were found to be predictors of clinical success. Hypoalbuminemia was associated with a lower rate of clinical success among patients with obesity who were treated with ceftriaxone 2 g every 12 hours.