SINGAPORE: Pfizer's Paxlovid has become the first oral tablet approved in Singapore for the treatment of COVID-19 in adult patients who are at risk of severe disease.
Interim authorisation for the oral medicine was granted under the Pandemic Special Access Route (PSAR) on Jan 31, the Health Sciences Authority (HSA) said on Thursday (Feb 3).
"This is the first oral tablet approved in Singapore for the treatment of mild to moderate COVID-19 in adult patients who are at high risk of progression to severe disease, to reduce the risk of hospitalisation and death," added the authority.
The pill should be taken twice a day for five days, HSA said, with treatment being initiated "as soon as possible after a diagnosis has been made, within five days of the onset of COVID-19 symptoms".
HSA added that the pill will be prescribed and prioritised to those at higher risk of severe COVID-19 illness, as directed by the Ministry of Health (MOH).
In response to queries from CNA, MOH confirmed an agreement had been signed with Pfizer's Singapore arm to purchase the drug. "We are working with Pfizer to deliver the first batches within this month," the ministry added.
Paxlovid has been found to reduce the risk of COVID-19 related hospitalisation or death by 88.9 per cent when treatment was given within three days of the onset of symptoms, according to HSA's review of the available clinical data based on rolling submissions of the results from an ongoing Phase II/III study.
When given within five days of the onset of symptoms, the pill reduces that risk by 87.8 per cent. The efficacy analysis included patients infected with the Delta variant.
HSA said in vitro data has also shown that Paxlovid is "active" against the prevailing variants of concern, including the Delta and Omicron variants.
More than 2,000 people aged 18 to 88 years old participated in the randomised, placebo-controlled study. All the participants had mild to moderate COVID-19 and one or more risk factors for progression to severe COVID-19, the authority said.
A total of 1,039 participants were given Paxlovid and the rest - 1,046 people - received placebos.
The results showed that 0.8 per cent of patients who received Paxlovid were hospitalised, compared to 6.3 per cent of those who received the placebo.
There were also no deaths in the Paxlovid group, compared to 12 deaths in the placebo group, HSA said.
PAXLOVID MAY INTERACT WITH OTHER MEDICATIONS
HSA said the safety data showed that Paxlovid is "well-tolerated".
"The incidences of adverse events reported in the clinical study were generally low. The common adverse events reported were mild to moderate, such as altered sense of taste, diarrhoea, vomiting, hypertension, muscle pain (myalgia) and chills."
The pill may interact with various medications, such as medicines for irregular heart rate, migraine, and cholesterol, said HSA, adding that it could increase the amount of these medications in the blood, leading to "serious adverse events".
"On the other hand, some medicines such as those for epileptic seizures could reduce the levels of Paxlovid resulting in a loss of anti-viral efficacy. The potential for drug interactions should be carefully considered by the prescribing doctor prior to treatment initiation."
Based on the available clinical evidence, HSA said the benefits of Paxlovid outweigh the risks, and there is a "favourable benefit-risk profile" for the treatment of mild to moderate COVID-19 in adults who are at high risk of progression to severe COVID-19.
As a requirement of interim authorisation, Pfizer will collect relevant safety data and monitor the use of Paxlovid.
HSA will also require Pfizer to continue submitting updated data from ongoing clinical studies to ensure the continued safety and efficacy of Paxlovid, including the pill's efficacy against prevailing variants.
MOH said it would "continue to monitor the development of COVID-19 therapeutics ... and purchase promising candidates to ensure Singapore has access to safe and effective COVID-19 treatments".
Interim authorisation of vaccines, medicines and medical devices under the PSAR can be terminated by HSA at any time, such as when new data suggests that their benefits no longer outweigh their risks.