CNS Aspergillosis and Cryptococcosis with Cytomegalovirus Pneumonia in a Patient with Chronic Lymphocytic Leukemia Treated with Acalabrutinib

Bruton's tyrosine kinase inhibitors (BTKis) are the preferred treatment for chronic lymphocytic leukemia (CLL). Despite their therapeutic benefits, these targeted agents have been associated with an increased risk of invasive infections. We describe a 68-year-old male who developed multiple bacterial, fungal and viral infections while on treatment with acalabrutinib. To our knowledge, this is the first reported case of concomitant CNS infections with Cryptococcus neoformans and Aspergillus fumigatus, along with cytomegalovirus (CMV) and herpes simplex virus type 1 (HSV-1) pneumonia while on acalabrutinib. This case adds to the scarce literature of fungal and bacterial infections associated with acalabrutinib, raising the suspicion that infection risk is a medication class effect for BTKis.

Mortality in recipients of allogeneic haematopoietic cell transplantation in the era of cytomegalovirus primary prophylaxis: a single-centre retrospective experience

OBJECTIVES

Allogeneic haematopoietic cell transplant (allo-HCT) recipients who are cytomegalovirus (CMV)-seronegative have better post-transplant outcomes than CMV-seropositive recipients. Letermovir (LTV) is approved for CMV primary prophylaxis in adults who are CMV-seropositive after allo-HCT, and its use is associated with improved long-term post-transplant outcomes. We analysed whether LTV has affected the relationship between CMV serostatus and post-transplant outcomes.

METHODS

We conducted a retrospective single-centre cohort study of allo-HCT recipients, stratified according to donor (D) and recipient (R). CMV serostatus and the use of LTV: D-/R-, R+/LTV-, and R+/LTV+. Outcomes measured were all-cause and non-relapse mortality, clinically significant CMV infection, graft-versus-host disease, and relapse up to week 48 after allo-HCT. The D-/R- group served as the reference for comparisons in univariate, competing risk regression, and cumulative incidence functions.

RESULTS

The analysis included 1071 consecutive allo-HCT recipients: 131 D-/R-, 557 R+/LTV-, and 383 R+/LTV+. All-cause mortality by day 100 was 6.1% for the D-/R- group, compared with 14.0% (p 0.024) and 7.8% (p 0.7) for the R+/LTV- and R+/LTV + groups, respectively. Non-relapse mortality by day 100 was 11.0%, 6.8% and 3.8% for R+/LTV-, R+/LTV+, and D-/R- groups, respectively, without significant difference. When including relapse as a competing event, the hazard ratio for non-relapse mortality was 1.83 (95% CI: 1.12-2.99, p 0.017) for R+/LTV- compared with D-/R- and 1.05 (95% CI 0.62-1.77, p 0.85) for R+/LTV + compared with D-/R-.

DISCUSSION

CMV primary prophylaxis with LTV abrogated the mortality gap based on CMV serostatus, a protective effect that persisted after discontinuation of primary prophylaxis.

The diagnostic dilemma for atypical presentation of progressive human Mpox

BACKGROUND

Human mpox has increasingly been reported worldwide since May 2022, with higher incidence in men who have sex with men (MSM) and persons living with HIV (PLHIV) with presentation typical for generalized macules and papules.

CASE PRESENTATION

We are describing a case of human mpox, which presented as widespread, atypical round verrucous lesions that went undiagnosed in the community for six months and was treated with antibacterials and antifungals given the similarity to skin manifestations associated with endemic mycoses.

CONCLUSIONS

Suspicion for human mpox should be high in young MSM and PLHIV who present with rash and mpox should be ruled out earlier.

2309. Ceftaroline for Central Nervous System and Ocular Infections

Background

Ceftaroline is increasingly used in combination therapy for methicillin resistant Staphylococcus aureus (MRSA) bacteremia. Animal models suggest ceftaroline penetrates the central nervous system (CNS) and vitreous humor; however, there are limited data which describe outcomes of patients treated with ceftaroline for infections with CNS or ocular involvement.

Methods

This was a single-center, retrospective study at an academic medical center. The primary objective was to describe outcomes in patients treated with ceftaroline for CNS or ocular infections. Patients who received ceftaroline from January 2015 to February 2022 were identified. Patients > 18 years who received > 48 hours of ceftaroline and had evidence of CNS or ocular involvement were included. Descriptive statistics were used.

Results

Ten patients met the inclusion criteria: six with CNS and four with ocular infections. The cohort was predominantly white (90%) and male (70%). The most common comorbidities were hypertension (70%) and diabetes (40%) (Table 1). Nine patients were treated for MRSA and one patient was treated for methicillin resistant Staphylococcus epidermidis (Table 2). Ceftaroline was salvage therapy in nine patients (90%), often following vancomycin and used as part of combination therapy (Table 3).

Of the four patients with ocular infections, all had MRSA bacteremia. Two patients (50%) had positive vitreal cultures and received intra-vitreal injections (Table 2). Most of these patients (75%) died during admission (Table 4). Of the six patients with CNS infections, injection drug use was more common than in patients with ocular involvement (33% vs 0%), as was immunocompromise (50% vs 0%) and the presence of endocarditis (33% vs 0%). Of the patients with CNS involvement, three had abnormal lumbar punctures and the remainder were diagnosed by CNS imaging (Table 2). Four patients with CNS involvement survived hospital stay (67%), and one of these had recurrence of CNS infection within 90 days (Table 4).

Conclusion

Although patients with CNS or ocular involvement represent a severely ill subset of staphylococcal infections, ceftaroline is a promising agent in combination therapy. Comparative data is needed to validate these findings.

Disclosures

All Authors: No reported disclosures.

2121. The Impact of Donor CMV Serostatus on Outcomes of CMV Infections in the Era of Letermovir

Background

Cytomegalovirus (CMV) infection is a frequent complication after allogeneic hematopoietic cell transplant (allo-HCT) and may increase the risk of other viral infections through its immunomodulatory effects. Donor CMV serology (seropositive [D+] or seronegative donor [D-]) in CMV-seropositive (R+) or seronegative recipients (R-) may impact outcomes post allo-HCT. We analyzed the significance of donor CMV serostatus in a large cohort of alloHCT recipients.

Methods

This is a single-center, retrospective cohort study of 651 allo-HCT recipients cared for at our institution between March 2016 and December 2018. Data on baseline demographics, transplant characteristics, preventive strategies, CMV infection characteristics, and transplant-related outcomes (development of graft versus host disease (GVHD), all-cause mortality, and non-relapse mortality) were collected. A univariate analysis was performed for outcomes of interest using CMV serostatus D-/R- as a control group.

Results

Out of the 651 allo-HCT recipients, 77 were D-/R-, 43 D+/R-, 290 D+/R+, and 241 D-/R+ (table 1). Most patients underwent HCT for AML (40%), received myeloablative conditioning (51%), and had a matched unrelated donor (MUD) HCT (46%). In 2018, letermovir was used in 27% of the D+/R+, 18% of the D-/R+ allo-HCT recipients (table 1) for a total of 116 (55%) allo-HCT recipients. Compared to the CMV D-/R- group, D+/R+ and D-/R+ groups (table 2) had a greater incidence of clinically signicant CMV infections (CS-CMVi) (3.9% vs. 40% vs. 50.6%; all p< 0.01, respectively), CMV end organ disease (0% vs. 14.8% vs. 19.1%; all p< 0.001, respectively), and refractory/resistant (R/R) CMV infections (0% vs. 5.5% vs. 12.4%; all p< 0.03, respectively) with 48 weeks of allo-HCT. CS-CMVi and R/R CMV was more common in D-/R+ allo-HCT when compared to D+/R+ group (50.6% vs. 40.0%, p< 0.001). D-/R+ allo-HCT had worse non-relapse mortality at day 100 compared to D-/R- (3.9% vs. 10.8%, p=0.07). Table 1:

1589. Long term hematopoietic cell transplant outcomes in patients at high risk for cytomegalovirus infections in the era of letermovir

Background

Letermovir (LTV) primary prophylaxis (PP) has reduced the incidence of clinically significant cytomegalovirus infection (CS-CMVi) in allogeneic hematopoietic cell transplant (allo-HCT) recipients. However, it is not clear if these are similar to low-risk recipients (seronegative donor [D-] and recipient [R-]). Prior studies have reported that D-/R- allo-HCT recipients have reduced relapse rates, graft versus host disease (GVHD), and overall mortality. We compared the clinical outcomes of R+ allo-HCT recipients with and without LTV PP to D-/R- allo-HCT recipients.

Methods

This is a single-center study of allo-HCT recipients who underwent transplantation between March 2016 and December 2018. Data on baseline and transplant characteristics were collected. Outcomes included incidence of CS-CMVi, GVHD, all-cause mortality, relapse and NRM. Univariate analysis was performed to compare outcomes in R+ with and without LTV PP cohorts to D-/R- cohort. Categorical and continuous variables were compared using Fisher’s exact test and Wilcoxon rank sum respectively. Survival curves were compared with the log-rank test. Patients who relapsed after transplant were excluded from NRM analysis.

Results

A total of 616 patients underwent an allo-HCT; 124 R+ were on LTV PP, 415 were R+ on no LTV PP as well as the 77 who were CMV D-/R-. When compared to D-/R- group, R+ group who received or not LTV PP were more likely to have AML and ALL, and underwent myeloablative conditioning. The incidence of CS-CMVi was the lowest in the D-/R- group (4%), followed by the R+ on LTV PP (17%), and the highest in the R+ group on no LTV PP (53%) (table 2). Kaplan-Meier survival analysis for NRM 1 year after transplant showed trends towards lower survival in R+ allo-HCT recipients who did not receive LTV PP when compared to the D-/R- group at day 200 and day 360 (p=0.07 vs. p=0.08, respectively). In addition, R+ allo-HCT on LTV PP had similar NRM at day 360 compared to D-/R- (p=0.77) and lower NRM at day 360 compared to R+ allo-HCT on no LTV PP (p=0.0192).

Conclusion

Our study showed a reduction in the rate of CS-CMVi within 48 weeks post HCT in high risk allo-HCT recipients on LTV. NRM was lower in R+ allo-HCT recipients on LTV PP when compared to those without LTV. No difference in NRM was seen between D-/R- allo-HCT and R+ allo-HCT on LTV PP.

Disclosures

Terri Lynn Shigle, PharmD, BCOP, Takeda: Advisor/Consultant Gabriella Rondon, MD, Omeros: Advisor/Consultant Elizabeth Shpall, MD, Adaptimmune: Advisor/Consultant|Affimed: License agreement|Axio: Advisor/Consultant|Bayer Helathcare Pharmaceuticals: Honoraria|Fibroblasts and FibrioBiologics: Advisor/Consultant|Navan: Advisor/Consultant|NY Blood Center: Advisor/Consultant|Takeda: License agreement Ella J. Ariza Heredia, MD, Merck & Co. Inc: Grant/Research Support Roy F. Chemaly, MD/MPH, Karius: Advisor/Consultant|Karius: Grant/Research Support.

Antivirals With Activity Against Mpox: A Clinically Oriented Review

Mpox virus is an emergent human pathogen. While it is less lethal than smallpox, it can still cause significant morbidity and mortality. In this review, we explore 3 antiviral agents with activity against mpox and other orthopoxviruses: cidofovir, brincidofovir, and tecovirimat. Cidofovir, and its prodrug brincidofovir, are inhibitors of DNA replication with a broad spectrum of activity against multiple families of double-stranded DNA viruses. Tecovirimat has more specific activity against orthopoxviruses and inhibits the formation of the extracellular enveloped virus necessary for cell-to-cell transmission. For each agent, we review basic pharmacology, data from animal models, and reported experience in human patients.

930. Clinically Significant CMV Infections in Patients with Lymphoma or Multiple Myeloma

Background

Clinically significant CMV infections (CS-CMVi) among patients with lymphoma and multiple myeloma (MM) have not been clearly defined, especially considering the new cancer therapies that have revolutionized cancer outcomes of these patients. This study aims at describing clinical outcomes of CS-CMVi in this patient population and identify risk factors for CS-CMVi.

Methods

This is a single-center, cohort study of all patients with lymphoma and MM who developed CS-CMVi between January 2017 and October 2020. Data was collected from the electronic medical records. CMV outcomes were defined according to the standardized definitions for clinical trials. Data was analyzed on IBM® SPSS version 26 using a logistic regression model for multivariate analysis.

Results

We identified 84 patients; 60 (71%) had lymphoma and 24 (29%) had MM (Table 1). CMV end organ disease was diagnosed in 53 (63%) patients as the initial CMV episode and the most common site was the lungs (68%). In our cohort, 25 (30%) patients had autologous HCT and 14 (17%) had CAR T cells infusions prior to CS-CMVi. Recurrent CS-CMVi occurred in 16 (19%) patients (Table 2). A 100-day all-cause mortality was 55%, at a median of 76 days (range 3 -1330 days) after the initial episode of CS-CMVi. CMV related mortality was 11% amongst patients with end organ disease. In multivariate analysis, female gender was associated with a higher risk of CMV end organ disease (OR 3.42, 95% CI 1.14-10.3) and MM with a lower risk of CMV end organ disease compared to lymphoma (OR 0.27, 95% CI 0.07-0.97) (Table 3). Interestingly, 16 (19%) patients received letermovir as secondary prophylaxis for a median of 94 days (range 5 to 339 days) and only 1 patient had recurrent CS-CMVi while on letermovir.

Conclusion

CS-CMVi, particularly end organ disease, are not uncommon among patients with lymphoma or MM. Routine CMV surveillance and the use of letermovir for secondary prophylaxis in this patient population should be evaluated in further studies.

Disclosures

Fareed Khawaja, MBBS, Eurofins Viracor (Research Grant or Support) Ella Ariza Heredia, MD, Merck (Grant/Research Support) Roy F. Chemaly, MD, MPH, FACP, FIDSA, AiCuris (Grant/Research Support)Ansun Biopharma (Consultant, Grant/Research Support)Chimerix (Consultant, Grant/Research Support)Clinigen (Consultant)Genentech (Consultant, Grant/Research Support)Janssen (Consultant, Grant/Research Support)Karius (Grant/Research Support)Merck (Consultant, Grant/Research Support)Molecular Partners (Consultant, Advisor or Review Panel member)Novartis (Grant/Research Support)Oxford Immunotec (Consultant, Grant/Research Support)Partner Therapeutics (Consultant)Pulmotec (Consultant, Grant/Research Support)Shire/Takeda (Consultant, Grant/Research Support)Viracor (Grant/Research Support)Xenex (Grant/Research Support)

922. The Impact of Clinically Significant CMV Infections on Other Viral Infections in the Era of Letermovir Primary Prophylaxis

Background

Cytomegalovirus (CMV) is a frequent complication after hematopoietic cell transplant (HCT) and may increase the risk of other viral infections through its immunomodulatory effects. Letermovir, a novel antiviral targeting the viral terminase complex, was approved for primary prophylaxis in CMV-seropositive adult recipients after allogeneic HCT (allo-HCT). Because of its efficacy and safety, letermovir has become the standard of care for primary prophylaxis against CMV during the first 100 days post-transplant. However, its impact on the frequency of other viral infections and non-relapse mortality (NRM), through its reduction in clinically significant CMV infections (CS-CMVi), is not known.

Methods

This is a single-center, retrospective cohort study of 150 allo-HCT recipients, including controls that were matched by the transplant type (match-unrelated, matched-related, cord, and haploidentical), cared for at our institution between March 2016 and December 2018. Baseline demographics, transplant characteristics, prophylaxis, CMV and other viral infections, and outcomes were collected (Table 1) and analyzed on IBM® SPSS version 26 using a binary logistic regression model for multivariate analysis. For univariate analysis, we used Chi-square and Fischer’s Exact Test.

Results

In our 2:1 matched cohort analysis, 50 patients received letermovir for primary prophylaxis during the first 100 days post-HCT, and 100 did not. In a univariate analysis with CS-CMVi as the outcome, there was a statistically significant difference in NRM at 24 and 48 weeks. Our data indicated a trend towards a decrease in other viral infections for those without CS-CMVi (Table 2). However, in a multivariate analysis accounting for primary prophylaxis with letermovir as an effect modulator, CS-CMVi did not demonstrate a significant impact on the frequency of other viral infections but was associated with NRM at week 24 and 48 (Table 3). Interestingly, having ALL and donor CMV seropositivity were protective factors against other viral infections (Herpesviridae).

Conclusion

Our study showed that CS-CMVi is associated with higher 24- and 48-week non-relapse mortality but with no increase in the incidence of other non-respiratory viral infections in this matched cohort of allo-HCT recipients.

Disclosures

Fareed Khawaja, MBBS, Eurofins Viracor (Research Grant or Support) Ella Ariza Heredia, MD, Merck (Grant/Research Support) Roy F. Chemaly, MD, MPH, FACP, FIDSA, AiCuris (Grant/Research Support)Ansun Biopharma (Consultant, Grant/Research Support)Chimerix (Consultant, Grant/Research Support)Clinigen (Consultant)Genentech (Consultant, Grant/Research Support)Janssen (Consultant, Grant/Research Support)Karius (Grant/Research Support)Merck (Consultant, Grant/Research Support)Molecular Partners (Consultant, Advisor or Review Panel member)Novartis (Grant/Research Support)Oxford Immunotec (Consultant, Grant/Research Support)Partner Therapeutics (Consultant)Pulmotec (Consultant, Grant/Research Support)Shire/Takeda (Consultant, Grant/Research Support)Viracor (Grant/Research Support)Xenex (Grant/Research Support)

Refractory and Resistant Cytomegalovirus after Hematopoietic Cell Transplant in the Letermovir Primary Prophylaxis Era

BACKGROUND

Cytomegalovirus (CMV) reactivation is one of the most common infectious complications after allogeneic hematopoietic cell transplant (HCT) and may result in significant morbidity and mortality. Primary prophylaxis with letermovir demonstrated a reduction in clinically significant CMV infections (CS-CMVi) in clinical trials of CMV-seropositive HCT recipients. This study aims at exploring the effect of primary letermovir prophylaxis in this population on the incidence and outcomes of refractory or resistant CMV infections.

METHODS

This is a single-center, retrospective cohort study of 537 consecutive CMV-seropositive allogeneic HCT recipients cared for during March 2016 to October 2018. Baseline demographics, HCT characteristics, CMV infections, treatment and mortality data were collected from the electronic medical record. CMV outcomes were defined according to the recently standardized definitions for clinical trials. Characteristics and outcomes were assessed according to receipt of primary letermovir prophylaxis.

RESULTS

Of 537 patients identified, 123 received letermovir for primary prophylaxis during the first 100 days after HCT, and 414 did not. In a multivariate analysis, primary prophylaxis with letermovir was associated with reductions in CS-CMVi (hazard ratio [HR] 0.26, 95% CI 0.16-0.41), CMV end-organ disease (HR 0.23, 95% CI 0.10-0.52), refractory or resistant CMV infection (HR 0.15, 95% CI 0.04-0.52), and non-relapse mortality at week 48 (HR 0.55, 95% CI 0.32-0.93). There was neither resistant CMV nor CMV-related mortality in the primary letermovir prophylaxis group.

CONCLUSIONS

Primary letermovir prophylaxis effectively prevents refractory or resistant CMV infections and decreases non-relapse mortality at week 48, as well as CS-CMVi and CMV disease after allogeneic HCT.

Immune reconstitution and severity of COVID-19 among hematopoietic cell transplant recipients

Severe acute respiratory syndrome coronavirus 2 can lead to life-threatening coronavirus disease 2019 (COVID-19) infections in patients with hematologic malignancies, particularly among hematopoietic cell transplant (HCT) recipients. We describe two patients with COVID-19 during the pre-engraftment period after HCT and review previous reports of COVID-19 in HCT recipients. Because of significant mortality from COVID-19, primarily after allogeneic HCT, early, preemptive, and optimal directed therapy may improve outcomes and reduce the mortality rate but still needs to be established in clinical trials.

580. Refractory and Resistant CMV Infections in Hematopoietic Cell Transplant Recipients in the Letermovir Primary Prophylaxis Era

Background

CMV reactivation is one of the most common infections after allogeneic hematopoietic cell transplantation (allo-HCT) and carries considerable morbidity and mortality. Primary prophylaxis with letermovir demonstrated in clinical trials reduction of the incidence of clinically significant CMV infection (CS-CMVi). This study aims at exploring the effect of letermovir primary prophylaxis on the occurrence of refractory or resistant CMV infections.

Methods

This is a single-center, retrospective cohort study of 537 consecutive allo-HCT CMV-seropositive recipients cared for between March 2016 and December 2018. Baseline demographics, transplant characteristics, CMV infections, treatment and mortality data were collected from the electronic medical record (Table 1). CMV outcomes were defined according to the standardized definitions for clinical trials. Data was analyzed on IBM® SPSS version 24 using a logistic regression model for multivariate analysis.

Results

Out of 537 patients identified, 123 received letermovir for primary prophylaxis during the first 100 days post-HCT and 414 did not. In a multivariate analysis, primary prophylaxis with letermovir was associated with a reduction in CS-CMVi (OR 0.11, 95% CI 0.06–0.20), CMV disease (OR 0.20, 95% CI 0.08–0.46) and refractory or resistant CMV infection (OR 0.11, 95% CI 0.02–0.49) (Table 2). Notably, there was no resistant CMV and no CMV-related mortality in the letermovir group. There was a trend towards lower all-cause mortality at day 100 in the letermovir group (OR 0.48, 95% CI 0.18–1.2).

Table 1 - Baseline Characteristics.

Table 2 - Multivariate Analysis of Clinical Outcomes.

Conclusion

Our study showed a strong association between primary prophylaxis with letermovir and reduction in refractory or resistant CMV infections and CMV disease in allo-HCT recipients.

Disclosures

Ella Ariza Heredia, MD, Merck Sharp & Dohme (Grant/Research Support)Oxford Immunotec (Grant/Research Support) Roy F. Chemaly, MD, MPH, FACP, FIDSA, Chimerix (Consultant, Research Grant or Support)Clinigen (Consultant)Merck (Consultant, Research Grant or Support)Novartis (Research Grant or Support)Oxford Immunotec (Consultant, Research Grant or Support)Shire/Takeda (Research Grant or Support)Viracor (Research Grant or Support)

568. Healthcare Cost and Length of Stay for Cytomegalovirus (CMV) Infection-Related Hospitalizations in Allogeneic Hematopoietic Cell Transplant (allo-HCT) recipients: A Multicenter Analysis

Background

CMV reactivation is associated with significant morbidity and mortality in allo-HCT recipients and could be a resource intensive condition to manage. Limited data are available on the economic ramification of CMV reactivation in allo-HCT. Therefore, we aimed to examine healthcare cost and length of hospital stay (LOS) among allo-HCT recipients treated for CMV infection.

Methods

We performed a retrospective cohort study that included 56 consecutive allo-HCT recipients who were diagnosed with CMV infection within 100 days post-transplant and admitted to two medical centers, University of Texas MD Anderson Cancer Center and University of Chicago, Department of Infectious Disease between January 2016 and December 2017. CMV-related hospitalization was determined as an inpatient admission with or for CMV reactivation within 100 days post-transplant. Data were limited to only the first CMV-related hospitalization. Descriptive statistics were reported on patient characteristics, first CMV-related hospitalization and costs.

Results

Most patients were 40 years or older (64%), female (55%), Caucasian (66%), CMV seropositive recipients (87%), received a matched unrelated donor HCT (49%) and had a myeloablative or reduced intensity conditioning regimen (65%) (Figure 1). The median duration of CMV episode was 40 days. Seventy-one percent of the patients were treated with foscarnet for CMV infection. Acute kidney injury was the most frequent CMV treatment-related complication (67%) followed by myelosuppression (55%) and end-stage renal disease (36%). Of 56 encounters, 16% required admission to intensive care unit with a median duration of 9 days. The median length of stay for hospitalization was 23 days and healthcare cost for CMV-related hospitalization was $71,840. The median hospitalization cost and LOS varied by reason for hospitalizations, type of anti-CMV therapy and treatment-related complications (Figure 2).

Figure 1. Baseline characteristics, CMV episodes, outcomes, and cost.

Figure 2. CMV Outcomes among allo-HCT recipients

Conclusion

Our study showed even a single episode of CMV-related hospitalization led to significant resource use and hospitalization costs. This study highlights the need for interventions to prevent of CMV-related hospitalization, thereby reducing associated cost and resource use.

Disclosures

Kathleen Mullane, DO, Pharm D, FIDSA, FAST, MERCK (Advisor or Review Panel member, Research Grant or Support, Speaker’s Bureau) Ella Ariza Heredia, MD, Merck Sharp & Dohme (Grant/Research Support)Oxford Immunotec (Grant/Research Support) Yuexin Tang, PhD, Merck and Co., Inc. (Employee) Amit D. Raval, PhD, Merck and Co., Inc (Employee) Roy F. Chemaly, MD, MPH, FACP, FIDSA, Chimerix (Consultant, Research Grant or Support)Clinigen (Consultant)Merck (Consultant, Research Grant or Support)Novartis (Research Grant or Support)Oxford Immunotec (Consultant, Research Grant or Support)Shire/Takeda (Research Grant or Support)Viracor (Research Grant or Support)

1545. Development of a Linear Mixed-Effect Pharmacodynamic Model to Quantify the Effects of Frequently Prescribed Antimicrobials on QT Interval Prolongation in Hospitalized Patients

Background

Torsades de pointes is a life-threatening ventricular tachycardia associated with prolongation of the QT interval. Many diseases and medications have been implicated as potentially prolonging the QT interval, but little data exists regarding the means of quantifying this risk. The aim of this study was to describe the impact of commonly used antimicrobials on the QT interval in hospitalized patients.

Methods

Demographic, diseases, laboratory, medication administration history and ECG recording data were collected from the electronic records of adult patients admitted, from July 2018 to December 2018, to two urban hospitals. A model for the QT interval comprised of four sub-models: gender, heart rate, circadian rhythm, and the drug and disease effects. Fixed and random effects with between occasion variability were estimated for the parameters. A Bayesian approach using the NUTS in STAN was used via the brms package in the R® software.

Results

Data from 1,353 patients were used with baseline characteristics shown in Table 1. Observed vs. predicted plots based on the training (Figure 1A) and validation data set (Figure 1B) showed a great fit. The parameters for QTc0, α, gender, and circadian rhythm were accurately identified (Table 2). Similarly, the model correctly described the expected impact of acute or chronic diseases on the QT interval. Uncertainty interval estimates (Figure 2) show that patients treated with fluconazole and levofloxacin are likely to present with a QT interval [mean (95% CI) of 6.84 (0.22,21.45) and 5.05 (0.15, 16.70), respectively], that is > 5 ms longer vs. no treatment, the minimum cutoff that should evoke further risk assessment of QT interval prolongation.

Conclusion

The model developed correctly describes the impact baseline risk factors have on the QT interval. Point estimates of QT interval prolongation show that patients treated with fluconazole and levofloxacin may be at considerable risk; while those treated with azithromycin or ciprofloxacin are more likely to be at an insignificant risk for QT interval prolongation during hospital admission. Further workup to quantify the impact of concomitant treatment with these and other at-risk medications is underway.

Disclosures

All authors: No reported disclosures.

1564. Target Attainment of Empiric Vancomycin Therapy to Achieve Safe and Effective Exposure When it Matters Most: How Much of the Drug Do We Really Need in the First 48 Hours?

Background

Empiric dosing of vancomycin (VAN) to reach targets is a daunting task due to the large variability observed in the pharmacokinetics of this agent. With the change to AUC driven dosing on the horizon, the goal of this study was to establish empiric dosing requirements of vancomycin that effectively achieve the desired AUC of 400 to 600 mg hours/L targets in the first 48 hours of therapy.

Methods

VAN TDM data were used in this analysis. A two-compartment model was fitted with Bayesian routines to establish the AUCs. Then, the AUC achieved was used to identify the desired total daily dose (TDD, capped at 4,500 mg) needed to attain an AUC in the target range for days 1 and 2, per patient. Next, multivariable regression was undertaken to predict this desired dose with frequently calculated weight and renal function indices. Last, model validation in a test data set based on calculated ME, RMSE and their 95% CI took place, and then the best model was used to simulate TDDs at 24 h intervals. To evaluate the agreement between the 2 pharmacists selecting the final TDDs by screening the simulated regimens, a weighted Kappa was calculated.

Results

1450 concentrations from 268 patients (60.9% male) with mean (IQR) age of 62.8 (52.7, 75) years, weight of 79.1 (63.2, 90.9) kg and CrCl of 76.7 (36.8, 110.6) mL/minute were analyzed. Fit of the model to data was excellent with R² = 0.98 (Figure 1). AUC attainment with actual dose vs. the AUCs based on the desired dose was poor (Figure 2). Final regression model [ME (95% CI) 31.58 (−160.38, 217.34) mgs; RMSE (95% CI) 761.98 (628.19, 895.93) mgs] identified adjusted body weight (ABW) (P = 0.02), CrCl (P < 0.001), age (P = 0.05) and sex (P = 0.01) on day 1, vs. CrCl (P < 0.001), age (P = 0.02) and sex (P = 0.002) on day 2 as predictors of TDD. Kappas showed near perfect agreement for day 1 (0.992, P < 0.01) and day 2 (0.883, P < 0.01) between the raters resulting in the selection of the final dosing regimens (Figures 3 and 4).

Conclusion

Our model accurately identified the 4 major variables most likely to explain VAN variability in predicting AUC in the first 48 hours. These detailed dosing recommendations—strengthened by rigorous external validation and near perfect between rater agreements—allow for the design of safe and effective AUC driven empiric dosing regimens.

Disclosures

All authors: No reported disclosures.

Outcomes associated with the use of a revised risk assessment strategy to predict antibiotic resistance in community-onset pneumonia: a stewardship perspective

Objectives

There is growing evidence that patients with community-onset pneumonia and recent healthcare exposure are not at equally high risk of infection with MDR organisms. An individualized approach is necessary with regard to risk assessment and choice of antibiotics.

Methods

We reviewed the records of 102 patients admitted for community-onset pneumonia, before and after the implementation of a revised risk assessment programme for MDR organisms using the drug resistance in pneumonia (DRIP) score. The primary aim of the study was to identify the effects of this intervention on antibiotic days of therapy (DOT), and secondary outcomes included all-cause readmissions and time to clinical improvement. Statistical analysis was performed using generalized linear regression and Cox hazards models.

Results

Implementation of the programme resulted in a decrease in anti-MRSA (-1.44 DOT, P = 0.007) and anti-pseudomonal (-2.03 DOT, P < 0.001) antibiotic utilization, but was not associated with a significant difference in the odds of readmissions (OR 0.64, 95% CI 0.16-2.57) or in time to clinical improvement (HR 1.19, 95% CI 0.62-2.21).

Conclusions

An individualized MDR organism risk assessment strategy using a clinical prediction score for community-onset pneumonia can decrease the utilization of broad-spectrum antibiotics without an increase in adverse outcomes.

1820. Indirect Standardization: A Convenient Benchmarking Approach to Antibiotic Utilization Based on Patient Mix

Background

Methods

Results

Conclusion

Disclosures

Waterborne fluoxetine disrupts feeding and energy metabolism in the goldfish Carassius auratus

Fluoxetine (FLX) is one of the most commonly detected pharmaceuticals in wastewater and bioaccumulates in wild-caught fish, especially in brain, liver and muscle tissues. Previous studies indicated that FLX is pharmacologically active in fish species exerting anorexigenic effects, but it is not clear whether waterborne FLX has any potential effects on regulating food intake and energy metabolism. In this study, we investigated the effect of two doses of FLX, an environmental concentration of 540 ng/L, and 100-times this concentration (54 μg/L), on feeding and key metabolic parameters in goldfish. Fish were exposed for a period of 28 days and changes in food intake and body mass were assessed. Pair-fed groups were maintained to discern primary FLX-induced effects from secondary metabolic responses induced by the decreased food intake. Additionally, an untreated control group and a fasted group were used to further compare physiological changes in the context of nutritional status of the animals. Significant decreases in food intake and weight gain were recorded in goldfish exposed to 54 μg/L FLX. Furthermore a significant decrease occurred in circulating glucose levels in the group exposed to 540 ng/L FLX. To elucidate potential mechanisms, we investigated gene expression of feeding neuropeptides in the neuroendocrine brain of goldfish as well as gene expression and enzymatic activity of glycolytic and gluconeogenetic enzymes in liver and muscle tissues. The results confirm brain gene expression patterns in line with potential anorexigenic effects in the hypothalamus, with increased expression in corticotropin-releasing factor (CRF) and decreased expression of neuropeptide Y (NPY). With respect to glucose metabolism, liver gene expression of the gluconeogenic enzyme fructose-1,6-bisphosphatase decreased and muscle hexokinase activity increased in fish exposed to 540 ng/L FLX. Overall, this study demonstrated anorectic properties of FLX at a dose of 54 μg/L FLX and moderate but significant effects on glucose metabolism in goldfish exposed to 540 ng/L FLX. Future studies investigating the importance of these changes in fish are warranted.