An experimental antiviral drug, peginterferon-lambda, has been shown in a Canadian clinical study to significantly accelerate recovery from Covid-19 symptoms in patients who do not need to be hospitalized.
Researchers at the University of Toronto Health Network (which includes the city's hospitals and institutes), led by Dr. Jordan Feld, who published the paper in The Lancet Respiratory Medicine, performed a randomized, double-blind (placebo) phase 2 clinical trial in 60 people, half of whom took the test drug and the rest the placebo.
It was found that those who received only one dose of peginterferon-lambda were at least four times more likely to clear the Covid-19 infection within a week than those who took placebo. Patients with the highest viral load were much more likely (79%) to clear the infection than the placebo group (38%). Of the 60 participants in the clinical trial, five needed to be admitted to the hospital emergency department due to worsening respiratory problems, and of these, four had taken a placebo and only one was taking regular medicine.
“This treatment has great therapeutic potential, especially at a time when we are seeing aggressive variants of the coronavirus spreading around the world that are less sensitive to both vaccines and antibody therapies,” said Dr. Feld, who has had experience with the use of the same drug against viral hepatitis.
“People who took peginterferon-lambda cleared the virus quickly and the effect was more noticeable in those with the highest viral levels. We also saw a trend for faster improvement of respiratory symptoms, “he added.
Rapid reduction of viral load is considered important both to prevent the deterioration of patients and to reduce the risk of transmission of coronavirus to others. “If we can reduce the viral load quickly, people will be less likely to spread the infection to those around them and may even be able to shorten the time required for self-isolation,” said Dr. Feld.
A larger phase 3 clinical trial is scheduled to begin soon, and additional studies of the same drug in Covid-19 inpatients are underway at three universities (Toronto, Harvard and Johns Hopkins).
Peginterferon-lambda is a protein produced in the body in response to viral infections and which has the ability to activate various cellular mechanisms to fight “invaders”. This interferon, unlike other interferons, is very active in the lungs, liver and intestine, places where the coronavirus can multiply. But it is not active in other parts of the body, which leads to fewer side effects than using other interferons. In the Canadian trial, patients who received it had similar side effects to those in the placebo group.
The peginterferon-lambda used in the study was a long-acting version of the drug developed by the American biopharmaceutical company Eiger BioPharmaceuticals and which can be administered by a single subcutaneous injection with a small needle (such as insulin).
