PremiumMonoclonal antibodies work well in reducing covid-19 related emergency department visits and hospitalizations when given early to high-risk patients, a study by the University of South Florida Health (USF Health) and Tampa General Hospital (TGH) has indicated. The collaborative study was published earlier this month in Open Forum Infectious Diseases journal.
Investigational monoclonal antibody therapies, administered intravenously, are specifically designed to block infection by SARS-CoV-2, the virus that causes covid-19. Similar to antibodies which are proteins that the body naturally produces to defend itself against disease, monoclonal antibodies are artificially created in the lab, tailor-made to fight the disease they treat. The therapy is being frequently used in India and several parts of the world for the treatment of covid-19.
The FDA has granted emergency use authorization (EUA) of MABs in outpatients with mild-to-moderate covid-19 at increased risk of developing severe disease. Such high-risk patients are prone to hospitalizations, mechanical ventilation, and other complications, including death from coronavirus. Following FDA, the Drugs Controller General of India (DCGI) in May too approved the treatment to be used in India.
If used under FDA guidelines, the researchers suggested, this treatment can ease the pandemic's continuing burden on patients and on limited healthcare resources. The academic medical center's retrospective study, conducted from 18 November 2020 to 5 January 2021 included high-risk outpatients with a confirmed covid-19 diagnosis, all experiencing mild-to-moderate symptoms for 10 days or less. A group of 200 patients received one of two monoclonal antibodies therapies (a single infusion)—either casirivimab/imdevimab, a combination drug made by Regeneron, or the medication bamlanivimab made by Eli Lilly. This treatment group was compared against a control group of 200 randomly selected outpatients who declined or were not referred for monoclonal antibodies during the same period.
The researchers found that overall, patients treated with monoclonal antibodies were significantly less likely to be hospitalized or visit the emergency department (13.5%) than the control patients (40.5%). These results remained significant when comparing the individual monoclonal antibody therapies against the control group.
The study found that there no deaths were reported in the monoclonal antibodies treated group, compared to 3.5% in the control group. Further, the patients treated with monoclonal antibodies within six days of symptom onset were significantly less likely to be hospitalized or visit the emergency department (7.7%) than those treated after six days (28.1%). The study data indicated that monoclonal antibodies are best given within seven days of initial symptoms to reduce the odds of hospitalization within 29 days of infusion.
"Reflecting on our findings, it would be prudent to consider decreasing the FDA eligibility window for MABs to within seven days of symptom onset," the study authors wrote. "These medications are a relatively scarce resource, and it would be practical to administer them to patients who are likely to see the most benefit."
Limited clinical trials previously indicated that monoclonal antibodies work best when given soon after diagnosis. But this USF Health-TGH collaborative study was one of the first to evaluate the practical effectiveness of MABs when administered exclusively to patients deemed at high risk for progression to severe covid-19. The FDA defines medical conditions and factors that place adults and children age 12 or older at higher risk for covid-19, including older age (65 plus), obesity, diabetes, immunosuppressive disorders or treatment, chronic lung disease, and cardiovascular disease, to name a few.
"Unfortunately, only a fraction of outpatients eligible for monoclonal antibodies receive them. We hope results like ours reinforce to the public and healthcare providers the importance of targeting timely monoclonal antibody treatment to this high-risk patient population to help minimize stress on health care systems during the covid-19 pandemic," said Asa Oxner, associate professor and vice chair of the Department of Internal Medicine, USF Health Morsani College of Medicine and study's senior author.
The study authors also concluded that maximizing the use of monoclonal antibody therapies under emergency use authorization (EUA) guidance has the potential to "keep high-risk covid-19 patients out of the hospital and reduce the negative impact on the healthcare system."
Never miss a story! Stay connected and informed with Mint. Download our App Now!!