December 17, 2020
By Douglas L. Jennings, PharmD, FACC, FAHA, FCCP, FHFSA, BCPS
As the scourge of COVID-19 continues to ravage the United States, hope remains firmly fixed towards vaccine as an end to the pandemic. While the first does of Pfizer’s ultra-chill vaccine were shipped this weekend, widespread use remains months away. In the meantime, clinicians will be forced to muster all available treatments to fight off the ever-surging numbers of COVID-19 infections.
In the last few weeks, two antibody therapies for non-hospitalized patients age 12 and older with mild to moderate symptoms of COVID-19 have received emergency use authorization (EUA). Bamlanivimab and casirivimab/imdevimab are single and combination monoclonal antibody therapies directed toward the spike protein of SARS-CoV-2. Both of these agents received an EUA based on limited clinical trial data. These data show potential decrease in progression to severe disease, but only when administered early in the course of the disease. Neither agent is considered standard of care.
Importantly, neither agent can be used in patients hospitalized for COVID-19 or in those requiring supplemental oxygen therapy, as these types of antibody products may actually worsen outcomes in this clinical scenario. So the message is clear that these therapies must be used early in the course of disease or not all.
This simple fact introduces logistical challenges. The US still struggles with testing—many patients experience delays in obtaining a test and then they often have to wait up to 24-48 hours for the PCR results. If patients do manage to get a positive test result within 10 days of symptom onset, and they aren’t hospitalized or they don’t require supplemental oxygen therapy, then they would still have to be at high-risk for progressing to severe COVID-19 and/or hospitalization in order to be considered for therapy. Examples of this high-risk criteria for adults is listed below (pediatric patients are different):
- body mass index (BMI) ≥35
- chronic kidney disease
- immunosuppressive disease
- Are currently receiving immunosuppressive treatment
- Are ≥65 years of age
- Are ≥55 years of age plus:
- cardiovascular disease, or
- hypertension, or
- chronic obstructive pulmonary disease/other chronic respiratory disease
There are additional logistical challenges that face outpatient pharmacists who will coordinate therapy with these new products. Once patients are diagnosed, they need to be scheduled for a visit to an outpatient infusion center, as this additional visit will expose other patients and the staff to an infected patient. The patient will need several hours for the visit, first to receive the infusion, then to be monitored for infusion reactions. Adding to these issues, the infusions themselves have limited stability (bamlanivimab is only stable at room temperature for 7 hours), which enhances the need for careful coordination between the pharmacy and infusion center staff.
The bottom line is that these therapies are approved for emergency use based on very limited data. They do not impact key endpoints like mortality or progression to ventilator support, but they may keep some high risk patients from needing hospitalization. There is a small but real potential for infusion related side-effects, some of which can be severe. For the time being, the greatest limiting factor for these products is their availability. Word on the street in New York City is that each health system was allocated only a handful of doses of these new therapies. So while there may be thousands who could potentially benefit, until more drug is actually available, and until the logistics of coordinating an outpatient infusion safely in a patient infected with COVID-19 are sorted out, these therapies seem to me less of a panacea and more like a boutique therapy.
Dr Jennings is currently an Associate Professor of Pharmacy at Long Island University and the clinical pharmacist for the Heart Transplant and LVAD teams at NewYork- Presbyterian Hospital Columbia University Irving Medical Center. He is an active researcher in his field, and he has published over 120 peer-reviewed abstracts and manuscripts, primarily focusing on the pharmacotherapy of patients under mechanical circulatory support. As a recognized expert in this area, he has been invited to speak at numerous national and international venues, including meetings in France, Saudia Arabia, India. Finally, Dr. Jennings has been active in professional organizations throughout his career. He is a fellow of the American College of Clinical Pharmacy, the American College of Cardiology, the Heart Failure Society of America, and the American Heart Association.
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