Bamlanivimab infusion experience at one academic emergency department.

Bamlanivimab (LY-CoV555) is an anti-spike IgG1 monoclonal antibody developed by Eli Lilly for the treatment of mild to moderate coronavirus disease 2019 (COVID-19) and received emergency use authorization (EUA) by the United States (US) Food and Drug Administration (FDA) in November 2020 [1]. Bamlanivimab was previously recommended for patients at high risk of progressing to severe COVID-19, including those with a body mass index ≥35, chronic kidney disease, diabetes, immunosuppressive disease or receiving immunosuppressive treatment, ≥65-years-old, or ≥ 55-years-old and a comorbidity (to include cardiovascular disease, hypertension, chronic obstructive pulmonary disease, or other chronic respiratory diseases) [2]. The drug was not recommended in patients hospitalized with COVID-19, those who required oxygen therapy due to COVID-19, or those requiring an increase in baseline oxygen flow rate due to COVID-19 [2]. Previous studies, including those in non-human primate models and human phase 2 clinical trials, suggested neutralization and rapid decline in viral load of the severe adult respiratory syndrome coronavirus 2 (SARS-CoV-2) [3,4]. However, more recently the FDA revoked bamlanivimab as a monotherapy agent in the US due to increased resistance to variants of SARS-CoV-2 [5].

With the paucity of data regarding bamlanivimab administration, we sought to perform a non-blinded retrospective chart review study at a single academic center evaluating patient demographics, emergency department (ED) evaluation, concomitant treatments, and their disposition. This study was reviewed by our regulatory office and determined to be exempt from institutional review board oversight. We searched within our ED's electronic medical record system, T-System™, from November 2020 to March 2021 for all encounters with a chief complaint related to COVID-19, including fever, cough, congestion, and shortness of breath and further identified patients who received bamlanivimab. Of note, our ED was the first hospital in a large metropolitan area to offer bamlanivimab infusions to outpatients who met inclusion criteria. During our study period, our ED evaluated 30,372 patients, 1160 (3.8%) of which had a chief complaint related to COVID-19 with a 15.3% admission rate. We identified 57 patients who received bamlanivimab infusions. At our institution, patients who met FDA criteria and consented for bamlanivimab received the infusion and were monitored for 1 h after the completion of the infusion in the ED. Though our center eventually established an infusion clinic separate from the ED after the study period, all patients in this study's cohort both received the infusion and were monitored in the ED. Additionally, to consolidate nurse staffing, our observation unit was closed and could not be used for post-infusion monitoring.

Of the 57 patients who received bamlanivimab, the ages ranged from 56- to 71-years-old, with a median age of 66-years-old. Most (35/57) patients were male. The emergency severity index (ESI) of patients receiving bamlanivimab ranged from 2 to 4, with 71% (41/57) of patients categorized as ESI level 3 (Table 1 ). Laboratory testing and select interventions were variable throughout this cohort. The most common workup included a complete blood cell count (45/57), complete metabolic panel (37/57), and diagnostic chest imaging (51/57). The most common interventions were antipyretic therapy (30/57) and fluid administration (32/57). The median length of stay (LOS) for patients receiving bamlanivimab was 490 min (95% confidence interval [CI] 412–556 min) compared to an overall median LOS of 216 min (95% CI 119–350 min) for patients not receiving bamlanivimab.

Table 1

Demographics, Emergency Severity Index and Disposition of Patients Receiving Bamlanivimab

Total patients		57
Demographics	Age range	66 (56–71)
	Male sex	61% (35)
Emergency severity index	1	0% (0)
	2	10% (6)
	3	71% (41)
	4	17% (10)
	5	0% (0)
Disposition	Admit	14% (8)
	Discharge	78% (45)
	Left against medical advice	3% (2)
	Transferred	3% (2)

Although intended for outpatient use, 14% (8/57) of patients who received bamlanivimab were admitted, 78% (45/57) were discharged, 3% (2/57) left against medical advice, and 3% (2/57) were transferred to another hospital. The authors investigated the 8 patients who were admitted after receiving bamlanivimab and found one had a non-ST segment elevation myocardial infarction defined by an elevated troponin level, two had worsening fever and malaise after the transfusion, one had a pulmonary embolism on computed tomography of the chest, one had sepsis with superimposed bacterial pneumonia, two developed new hypoxia and oxygen requirement after the transfusion, and one was found to have moderate hyponatremia.

This retrospective study represents the first report of utilizing the ED for bamlanivimab infusions during the COVID-19 pandemic. However, this study has several limitations. The authors did not perform follow-ups of patients who received bamlanivimab and subsequently cannot make any conclusions regarding its efficacy in preventing progression to severe COVID-19 at our center. This was a deliberate decision due to the lack of specific SARS-CoV-2 variant testing at the time of this study. Additionally, we did not investigate whether patients receiving bamlanivimab at our ED strictly met its intended inclusion criteria. Finally, we recognize the limited generalizability of our study due to our center's aggressive adoption and ready supply of the drug. Nevertheless, our use of this novel intervention demonstrates the flexibility and rapid implementation in the ED for providing a potentially lifesaving intervention as part of the front-line hospital response. Additionally, we found that infusion therapy significantly increased the median length of stay for patients in our ED, likely due to constraints on nursing staff and closure of our observation unit during the surges of COVID-19, including the entirety of the study period. Future studies are needed to determine if the ED is an appropriate setting for the administration of EUA therapies and its effect on ED length of stays, repeat visits, and delayed complications in novel drugs intended for outpatient use. However, our study demonstrates the ability of an ED setting to rapidly adopt a new cutting-edge therapy and the pivotal role that ED's have in pandemic medical care.

Funding

None.

Disclaimer

The opinions reflected in this manuscript are those of the authors alone and do not reflect those of the United States Air Force, United States Army, Department of Defense, or Federal Government. All authors equally contributed in the creation of this manuscript, have no financial disclosures, and did not receive any external funding.