Corticosteroids 'mainstay' for treatment of severe COVID-19 in Singapore; new antibody therapy to be used soon
SINGAPORE: Corticosteroids such as dexamethasone are the "mainstay" for the treatment of severe COVID-19 in Singapore, while an antibody therapy will also soon be used to treat patients with mild to moderate symptoms.
Dr Shawn Vasoo, clinical director at the National Centre for Infectious Diseases (NCID), told CNA on Wednesday (Oct 6) that steroids exert an anti-inflammatory effect, and it is this inflammation that is the "main driver of disease" in cases of severe COVID-19.
Corticosteroids are normally used to treat a range of allergic reactions, such as rheumatoid arthritis or asthma.
A landmark trial found a "significantly lower" mortality rate in COVID-19 patients given dexamethasone if they were receiving oxygen or were on a ventilator. There was an overall relative risk reduction of death by about 11 per cent, at 28 days after the patient acquired COVID-19, said Dr Vasoo.
As of noon on Tuesday, 1,512 COVID-19 cases in Singapore were warded in hospital, with 247 cases requiring oxygen supplementation. There were 34 COVID-19 cases in the intensive care unit.
NEW ANTIBODY THERAPIES
Two antibody therapies have been recently granted interim authorisation under the Pandemic Special Access Route by the Health Sciences Authority (HSA) to treat those with mild to moderate COVID-19.
"One of the antibodies we have started to use is a drug called sotrovimab, and casirivimab-imdevimab is another one which will come into clinical use soon in Singapore," said Dr Vasoo.
Casirivimab-imdevimab, made by Roche-Regeneron, was given interim authorisation on Sep 21.
"This will allow infectious diseases specialists to use the combination monoclonal antibodies therapy for the treatment of COVID-19 patients aged 18 years and older, who do not require oxygen supplementation and are at risk for progression to severe COVID‐19," said HSA.
HSA said clinical data from a Phase 3 study showed that casirivimab-imdevimab demonstrated a 70 per cent reduction in the "relative risk for progression to requiring acute treatment in hospital or death due to COVID-19".
Sotrovimab was granted interim authorisation on Jun 30. HSA said trial clinical data showed the drug demonstrated a 79 per cent reduction in the relative risk of progression to requiring acute treatment in hospital or death from COVID-19.
Last year, an antiviral drug remdesivir - created originally to tackle Ebola - was conditionally approved for treating COVID-19 patients in Singapore.
Dr Vasoo told CNA that some high-risk patients, for example those with pneumonia or are a risk of progression to pneumonia and severe disease, may receive remdesivir.
"For patients with severe COVID-19 (ie who need oxygen support), remdesivir can still be considered, but as an antiviral, its utility is greater earlier in the disease course," the clinical director said.
HIV drugs lopinavir and ritonavir - among the first drugs used to treat some COVID-19 patients in Singapore - are not administered by the NCID because “they have not shown efficacy in randomised controlled trials to date”, Dr Vasoo said.
"The major definitive trials which have informed practice have been completed. It is unlikely that any further new, groundbreaking trials will be attempted," he added.
MSD ENTERS AGREEMENT WITH SINGAPORE
Pharmaceutical company MSD announced on Wednesday morning that it has entered a supply and purchase agreement with Singapore to provide molnupiravir, an investigational antiviral drug to treat COVID-19, if it is authorised or approved.
The drug, which is being developed in collaboration with Ridgeback Biotherapeutics, is being evaluated in two Phase 3 clinical trials, said MSD, which is known as Merck in the United States and Canada.
The company said last Friday that molnupiravir has been shown during trials to reduce the risk of hospitalisation or death by about 50 per cent for patients with mild to moderate COVID-19.
It has also been shown to be active against the most common variants of the COVID-19 virus, including the highly infectious Delta variant.