Abatacept Pharmacokinetics and Exposure Response in Patients Hospitalized With COVID-19: A Secondary Analysis of the ACTIV-1 IM Randomized Clinical Trial

Importance

The pharmacokinetics of abatacept and the association between abatacept exposure and outcomes in patients with severe COVID-19 are unknown.

Objective

To characterize abatacept pharmacokinetics, relate drug exposure with clinical outcomes, and evaluate the need for dosage adjustments.

Design, Setting, and Participants

This study is a secondary analysis of data from the ACTIV-1 (Accelerating COVID-19 Therapeutic Interventions and Vaccines) Immune Modulator (IM) randomized clinical trial conducted between October 16, 2020, and December 31, 2021. The trial included hospitalized adults who received abatacept in addition to standard of care for treatment of COVID-19 pneumonia. Data analysis was performed between September 2022 and February 2024.

Exposure

Single intravenous infusion of abatacept (10 mg/kg with a maximum dose of 1000 mg).

Main Outcomes and Measures

Mortality at day 28 was the primary outcome of interest, and time to recovery at day 28 was the secondary outcome. Drug exposure was assessed using the projected area under the serum concentration time curve over 28 days (AUC0-28). Logistic regression modeling was used to analyze the association between drug exposure and 28-day mortality, adjusted for age, sex, and disease severity. The association between time to recovery and abatacept exposure was examined using Fine-Gray modeling with death as a competing risk, and was adjusted for age, sex, and disease severity.

Results

Of the 509 patients who received abatacept, 395 patients with 848 serum samples were included in the population pharmacokinetic analysis. Their median age was 55 (range, 19-89) years and most (250 [63.3%]) were men. Abatacept clearance increased with body weight and more severe disease activity at baseline. Drug exposure was higher in patients who survived vs those who died, with a median AUC0-28 of 21 428 (range, 8462-43 378) mg × h/L vs 18 262 (range, 9628-27 507) mg × h/L (P < .001). Controlling for age, sex, and disease severity, an increase of 5000 units in AUC0-28 was associated with lower odds of mortality at day 28 (OR, 0.52 [95% CI, 0.35-0.79]; P = .002). For an AUC0-28 of 19 400 mg × h/L or less, there was a higher probability of recovery at day 28 (hazard ratio, 2.63 [95% CI, 1.70-4.08] for every 5000-unit increase; P < .001). Controlling for age, sex, and disease severity, every 5000-unit increase in AUC0-28 was also associated with lower odds of a composite safety event at 28 days (OR, 0.46 [95% CI, 0.33-0.63]; P < .001). Using the dosing regimen studied in the ACTIV-1 IM trial, 121 of the 395 patients (30.6%) would not achieve an abatacept exposure of at least 19 400 mg × h/L, particularly at the extremes of body weight. Using a modified, higher-dose regimen, only 12 patients (3.0%) would not achieve the hypothesized target abatacept exposure.

Conclusions and Relevance

In this study, patients who were hospitalized with severe COVID-19 and achieved higher projected abatacept exposure had reduced mortality and a higher probability of recovery with fewer safety events. However, abatacept clearance was high in this population, and the current abatacept dosing (10 mg/kg intravenously with a maximum of 1000 mg) may not achieve optimal exposure in all patients.

Trial Registration

ClinicalTrials.gov Identifier: NCT04593940.

Septic arthritis due to Nocardia brasiliensis and a review of nocardiosis as a cause of arthritis

Bacteria of the genus Nocardia are implicated in several disease processes but are a rare cause of septic arthritis. Typically, the cause of Nocardia septic arthritis is dissemination from a pulmonary infection in an immunocompromised host. Herein we present a case of a 64-year-old male who had received a long course of prednisone for membranous nephropathy and developed a septic arthritis due to Nocardia brasiliensis. He was treated sequentially with trimethoprim-sulfamethoxazole and amoxicillin-clavulanate, linezolid and amoxicillin-clavulanate, tigecycline and amoxicillin-clavulanate, and omadacycline and amoxicillin-clavulanate. To our knowledge, only two prior cases of Nocardia brasiliensis septic arthritis without antecedent trauma to the joint or local skin breakdown have been reported. A review of the literature identified 19 other cases of Nocardia septic arthritis. This case reinforces the need to consider Nocardia infection in the differential diagnosis in the immunocompromised patient with concurrent pulmonary infection and septic arthritis.

1402. NTM Infections; A Rising Global Health Problem/Clinical Characteristics and Outcomes of Patients with Non-Tuberculous Mycobacterial Infections at Two Tertiary Academic Medical Centers

Background

Non-Tuberculous Mycobacteria (NTM) cause infections in immunocompetent as well as immunocompromised individuals affecting pulmonary and extra pulmonary sites. These pathogens are widely distributed globally and recent reports have shown their rise in many developed countries. Our study aimed to assess the disease magnitude, describe patient characteristics and risk factors, assess diagnostic and therapeutic measures and review outcomes furthering our understanding of the overall disease process.

Methods

We conducted a retrospective, multicenter review of patients with positive NTM cultures treated at University Hospital System and South Texas Veterans Health Care System (STVHCS) from 2011 to 2018. Infections were classified as pulmonary or extrapulmonary, and we recorded demographics, microbiological data, treatment regimens, duration, complications, follow-up and mortality. All categorical variables were described using percentages and compared between groups using the chi-square test.

Results

A total of 176 patients were included for analysis, of which 111 (63.1%) met criteria for NTM disease (2020 ATS/IDSA). The most common cultured mycobacterium was M. Avium Complex (MAC). M. abscessus-chelonae was more commonly associated with clinical disease and isolated from an extra pulmonary site whereas M. simiae complex had similar distribution between the infected and un-infected groups. Over 50% of patients received treatment (80% in the infected group). Cure was seen in 47.2%, all-cause mortality was 27% at last follow-up. Median duration of therapy was 10 months. 47% of patients experienced adverse effects which led to treatment discontinuation in one third of patients. Patients who were able to achieve a cure received a longer duration of therapy (12 vs 7 months; not statistically significant) and treatment was halted more commonly in the group that did not achieve eventual cure (42.6% vs. 16.7%, p=0.007).

Conclusion

NTM infections represent a therapeutic challenge with low cure rates and high mortality. An understanding of the risk factors, treatment options and outcomes is essential to guide appropriate management. Our study highlights high rates of adverse effects and discontinuation which precludes prolonged courses of therapy required to achieve cure.

Disclosures

All Authors: No reported disclosures

Personal Protective Equipment and Donning and Doffing Techniques in the Cardiac Catheterization Laboratory During the COVID-19 Pandemic: Insights From an Internet Search for Protocols

Background: Due to the ongoing coronavirus disease 2019 (COVID-19) pandemic, a need for precise donning and doffing protocols for personal protective equipment (PPE) among healthcare infrastructures is paramount. Procedures involving the cardiac catheterization laboratory (CCL) are routinely non-aerosolizing but have the potential for rapid patient deterioration, creating the need for aerosolizing generating procedures. Multiple societal and governmental guidelines on the use of PPE during medical procedures are available on Internet websites; however, there is limited literature available in peer-reviewed formats in this context. This study aims to provide an overview of current PPE donning and doffing protocols specific to the catheterization laboratory.

Methods: A series of internet searches regarding donning and doffing of PPE in the CCL including published articles and internet protocols were compiled and compared using Pubmed.gov, Google.com, www.twitter.com, and www.youtube.com.

Results: Most institutions used N95 masks, shoe covers, at least one head covering, face shield or goggles, two pairs of gloves, and inner and outer gowns. Doffing variation was greater than donning. Doffing has the potential to contaminate the healthcare worker (HCW), and therefore, this step of PPE management requires further study. Common steps in temporal priority included cleaning of gloved hands, removal of outer (or only) gown, removal of outer gloves, repeat gloved hand cleaning, removal of facial PPE last, and a final non-gloved hand cleaning.

Conclusions: This analysis provides a summary of commonly used practices that may be considered when designing CCL-specific PPE protocols. Analysis of consistent steps from the literature led the authors to formulate a suggested protocol for CCL HCWs when performing procedures on patients with confirmed or suspected/unknown COVID-19.

314. A Retrospective Review of Dalbavancin Utilization at an Academic Medical Center

Background

Dalbavancin is a novel long-acting lipoglycopeptide with increasing utilization for management of bone and joint infections as a two-dose regimen. The purpose of this study is to describe the patient characteristics, evaluate clinical outcomes, and calculate inpatient hospital days saved with use of dalbavancin as outpatient parenteral antimicrobial therapy (OPAT).

Methods

A retrospective review of patients treated with dalbavancin at University Hospital was conducted from Aug 2019- March 2020. Patients ≥ 17 yrs of age with plan to receive at least 1 dose of dalbavancin were included. All patients were initially evaluated by, and had clinic follow up with, an infectious disease physician. Information on baseline demographics, infection characteristics, treatments, and outcomes were recorded from the EMR.

Results

42 patients met the study criteria. 62% were males with a median age of 49 yrs. 67% of patients had diabetes and 12% had a documented history of intravenous drug use. The most common indication was osteomyelitis (71%). S. aureus was the most commonly isolated organism in monomicrobial infections (MRSA 24%, MSSA 9.5%) and often a component of polymicrobial infections (33%). 90.5% of patients were adherent to their prescribed therapy; 1 patient missed both doses and 3 only received 1 of their recommended doses. Adverse effects were mild and noted in only 4 patients. 24 patients (57%) received concomitant antibiotics. 45% of patients achieved a cure with another 12% were classified as improved but requiring further antibiotics. 31% (N=13) had failure of therapy of which, 69% (N=9) did not achieve prior source control. 5 patients were lost to follow up. Our health system saved 160 inpatient days through dalbavancin use.

Conclusion

Dalbavancin treatment had a high adherence rate with minimal adverse effects and achieved a positive outcome in 57% of patients. Of patients that failed, the majority did not have appropriate source control. Dalbavancin use has the potential to save inpatient days while offering a more convenient option for treatment. However, further studies should be conducted to evaluate its efficacy in comparison to standard of care therapy at our institution.

Disclosures

All Authors: No reported disclosures

802. Use of N-Acetylcysteine for Prevention and Treatment of Isoniazid Induced Liver Injury During Treatment of Mycobacterial Infections

Background

Hepatotoxicity secondary to therapy for Mycobacterium tuberculosis (MTB) is a common complication that may lead to treatment interruption. N-Acetylcysteine (NAC) exerts a hepatoprotective effect by repleting glutathione stores and enhancing the cellular antioxidant defense mechanism. NAC has been found to be protective against liver toxicity in animals treated for MTB infection. Randomized controlled trials have shown that its use in humans also decreases the risk of hepatotoxicity associated with anti-MTB treatment but there is minimal data regarding its utility for treatment of liver toxicity.

Methods

Patients who received NAC from January 2012 to March 2018 for prophylaxis and treatment of increasing liver function tests (LFTs) while on isoniazid (INH) were included. A retrospective review of the medical record system was performed.

Results

Nineteen patients were included. Eight received NAC for treatment. The average age was 49 years. Seventy percent of patients were male. The mean BMI was 25. Five patients had underlying liver cirrhosis and two had hepatic steatosis. Eleven patients had Hepatitis C (HCV) and one had active Hepatitis B infection. Ten patients had MTB pulmonary infection, thee had latent TB infection, two meningitis, and three had disseminated disease. One patient was treated for atypical mycobacterial infection. The dose of NAC used was 600 mg oral twice daily and the duration was variable.

The prophylaxis group had stable LFTs during treatment, except for two patients whose enzymes increased more than three times the upper limit of normal. These two patients had underlying HCV and liver cirrhosis. Only one required discontinuation of INH. This group received NAC for an average of 47 days. The treatment group had a favorable trend of liver enzymes after NAC initiation, with levels significantly improving by day 14 (Figures 1 and 2). Three patients did not require discontinuation of antibiotics. INH was stopped prior to NAC initiation in four patients. No side effects of NAC were documented in any patient.

Conclusion

NAC is a safe and effective measure to prevent and treat hepatotoxicity secondary to INH therapy. More studies are needed to determine its optimal dose and duration for this indication.

Disclosures

All authors: No reported disclosures.

Tuberculosis Patients Who Are A Potential Source for Unprotected Exposure in Health Care Systems: A Multicenter Case Control Study

Setting

Five health care systems in Texas.

Objective

To describe the epidemiology of inadequate isolation for pulmonary tuberculosis leading to tuberculosis (TB) exposures from confirmed TB patients and the patient factors that led to the exposures.

Design

A retrospective cohort and case-control study of adult patients with TB resulting in exposures (cases) vs those TB patients who did not result in exposures (controls) during January 2005 to December 2012.

Results

There were 335 patients with pulmonary TB disease, 199 cases and 136 controls. There was no difference between groups in age (46 ± 14.6 vs 45 ± 17 years; P > .05), race, or substance abuse. Cases were more likely to be transplant recipients (adjusted odds ratio [AOR], 18.90; 95% CI, 1.9-187.76), have typical TB chest radiograph (AOR, 2.23; 95% CI, 1.1-4.51), and have positive acid-fast bacilli stains (AOR, 2.36; 95% CI, 1.31-4.27). Cases were less likely to have extrapulmonary disease (AOR, 0.47; 95% CI, 0.24-0.95).

Conclusions

TB exposure resulting from inadequate isolation is frequent in health care settings. Extrapulmonary involvement resulted in earlier airborne isolation. Being a transplant recipient, having chest radiograph findings typical for TB, and sputum positivity acid-fast bacilli upon staining were associated with increased risk of inadequate isolation.

Treatment of infections due to resistant Staphylococcus aureus

This chapter reviews data on the treatment of infections caused by drug-resistant Staphylococcus aureus, particularly methicillin-resistant S. aureus (MRSA). This review covers findings reported in the English language medical literature up to January of 2013. Despite the emergence of resistant and multidrug-resistant S. aureus, we have seven effective drugs in clinical use for which little resistance has been observed: vancomycin, quinupristin-dalfopristin, linezolid, tigecycline, telavancin, ceftaroline, and daptomycin. However, vancomycin is less effective for infections with MRSA isolates that have a higher MIC within the susceptible range. Linezolid is probably the drug of choice for the treatment of complicated MRSA skin and soft tissue infections (SSTIs); whether it is drug of choice in pneumonia remains debatable. Daptomycin has shown to be non-inferior to either vancomycin or β-lactams in the treatment of staphylococcal SSTIs, bacteremia, and right-sided endocarditis. Tigecycline was also non-inferior to comparator drugs in the treatment of SSTIs, but there is controversy about whether it is less effective than other therapeutic options in the treatment of more serious infections. Telavancin has been shown to be non-inferior to vancomycin in the treatment of SSTIs and pneumonia, but has greater nephrotoxicity. Ceftaroline is a broad-spectrum cephalosporin with activity against MRSA; it is non-inferior to vancomycin in the treatment of SSTIs. Clindamycin, trimethoprim-sulfamethoxazole, doxycycline, rifampin, moxifloxacin, and minocycline are oral anti-staphylococcal agents that may have utility in the treatment of SSTIs and osteomyelitis, but the clinical data for their efficacy is limited. There are also several drugs with broad-spectrum activity against Gm-positive organisms that have reached the phase II and III stages of clinical testing that will hopefully be approved for clinical use in the upcoming years: oritavancin, dalbavancin, omadacycline, tedizolid, delafloxacin, and JNJ-Q2. Thus, there are currently many effective drugs to treat resistant S. aureus infections and many promising agents in the pipeline. Nevertheless, S. aureus remains a formidable adversary, and despite our deep bullpen of potential therapies, there are still frequent treatment failures and unfortunate clinical outcomes. The following discussion summarizes the clinical challenges presented by MRSA, the clinical experience with our current anti-MRSA antibiotics, and the gaps in our knowledge on how to use these agents to most effectively combat MRSA infections.

The higher the decrease in the standardized uptake value of positron emission tomography after chemoradiation, the better the survival of patients with gastroesophageal adenocarcinoma

BACKGROUND

Postchemoradiation percentage decrease in standardized uptake value (SUV) of positron emission tomography (PET) from baseline correlates with overall survival (OS) and pathologic response. Analyses of dichotomized data are commonly reported. The authors analyzed percentage SUV decrease as both dichotomized and continuous variables.

METHODS

The authors assessed 151 consecutive patients with gastroesophageal adenocarcinoma who had chemoradiation and surgery. Baseline and postchemoradiation PET/computed tomography imaging was performed. The log-rank test and Cox proportional hazards models were used to associate percentage SUV changes and OS, and logistic regression models were used to detect the association between percentage SUV changes and pathologic response.

RESULTS

A >52% SUV decrease (dichotomized analysis) was associated with a longer OS (log-rank test, P = .023). The univariate Cox proportional hazards model indicated that greater percentage SUV decrease (as a continuous variable) was associated with a lower risk of death (hazard ratio [HR], 0.99; P = .01). Pathologic response (< or =50% residual cancer) was associated with longer OS (P = .003). Patients with chemoradiation resistance (>50% residual cancer) tended to have a higher risk of death than those with chemoradiation sensitivity (0-50% residual cancer; HR, 2.12; P = .099). In the multivariate model, the percentage SUV decrease (as a continuous variable) was the only prognosticator of OS (P = .01). The percentage SUV decrease was nonsignificantly associated with pathologic complete response (univariate odds ratio [OR], 1.01; P = .06 and multivariate OR, 1.03; P = .07).

CONCLUSIONS

The greater the decline in SUV after chemoradiation, the longer is the OS of gastroesophageal adenocarcinoma patients. The percentage SUV decrease as a continuous variable is a better prognosticator of OS than its dichotomized assessments.

Influence of the baseline 18F-fluoro-2-deoxy-D-glucose positron emission tomography results on survival and pathologic response in patients with gastroesophageal cancer undergoing chemoradiation

BACKGROUND

In patients with esophageal cancer who receive chemoradiation, tools to predict/prognosticate outcome before administering therapy are lacking. The authors evaluated initial standardized unit value (iSUV) of 18F-fluoro-2-deoxy-D-glucose positron emission tomography and its association with overall survival and the degree of pathologic response after surgery.

METHODS

The authors analyzed 161 patients with esophageal adenocarcinoma who had chemoradiation followed by surgery. The log-rank test, univariate Cox proportional hazards model, Kaplan-Meier survival plot, and Fisher exact test were used to analyze dichotomized iSUV and its association with overall survival and pathologic response.

RESULTS

The median age of 161 patients was 61 years (range, 26-80 years) and the majority of patients had lower esophageal or gastroesophageal junction involvement. All patients received fluoropyrimidine and, most commonly, a taxane or platinum compound with concomitant radiation. The median radiation dose was 45 grays (Gy) (range, 45 Gy-50.4 Gy). The median iSUV for all patients was 10.1 (range, 0-58). Using the Fisher exact test, iSUV was not found to be associated with the location of the primary cancer. iSUV higher than the median (10.1) was associated with a better pathologic response (P = .06). Patients with primary cancer with iSUV >10.1 had a lower risk for death (hazards ratio of 0.56) compared with those with iSUV < or = 10.1. Higher iSUV was nonsignificantly associated with improved survival (P = .07).

CONCLUSIONS

Data from the current study suggest that lower iSUV is associated with poor survival and lower probability of response to chemoradiation. iSUV needs to be further evaluated because it may be used to complement other imaging or biomarker assessments to individualize therapy.

Influence of induction chemotherapy and class of cytotoxics on pathologic response and survival after preoperative chemoradiation in patients with carcinoma of the esophagus

BACKGROUND

Patients with localized esophageal cancer (LEC) have diverse outcomes (post-therapy pathologic response, disease-free survival [DFS], and overall survival [OS]) after preoperative chemoradiation (P-CTRT), dictated also by inherent molecular heterogeneity. Whether the type of therapy influences the outcomes remains largely unanswered. It is hypothesized that induction chemotherapy (IC) or the type of cytotoxics used would not influence patient outcomes.

METHODS

In this retrospective analysis, consecutive patients with LEC who had P-CTRT were analyzed. Data were collected regarding age, sex, baseline clinical stage, location, type of cytotoxics, post-therapy pathology, DFS, and OS. IC and the type of cytotoxics used were found to be correlated with DFS, OS, and post-therapy pathologic response.

RESULTS

A total of 180 patients with LEC (119 had IC before P-CTRT, all had received 5-fluorouracil, 87 had received a taxane, and 57 had received a platinol) were analyzed. The median survival (MS) of all patients was 57.7 months and the 3-year and 5-year OS rates were 65.4% and 46.5%, respectively. The type of therapy appeared to have no influence on the outcome: IC versus no IC (P = .58) or platinol versus taxane versus platinol plus taxane (P = .63). Similarly, the type of pathologic response was not found to be influenced by IC (P = .18) or the type of cytotoxics used (P = .42). The data were similar for DFS.

CONCLUSIONS

IC or the type of cytotoxics used with radiation for patients with LEC does not appear to influence OS, DFS, or the type of pathologic response after therapy, suggesting that a plateau has been reached. It remains to be seen whether the use of biochemoradiotherapy can provide an advantage in outcome.