British pharmaceuticals giant AstraZeneca on Monday revealed more positive results from a trial of a treatment for Covid-19 symptoms.

The drug, made from a combination of two antibodies, achieved a "statistically significant reduction in severe Covid-19 or death" in non-hospitalised patients with mild-to-moderate symptoms, AstraZeneca said in a statement.

The group's treatment, known as AZD7442, has been undergoing phase 3 or final clinical trials to assess its safety and efficacy.

"With continued cases of serious Covid-19 infections across the globe, there is a significant need for new therapies like AZD7442 that can be used to protect vulnerable populations ... and can also help prevent progression to severe disease," said principal trial investigator Hugh Montgomery.

"These positive results show that a convenient intramuscular dose of AZD7442 could play an important role in helping combat this devastating pandemic."

The trial involved 903 participants and 90 percent of them were people at high risk of progression to severe Covid-19.

AstraZeneca's separate Covid vaccine, developed with the University of Oxford, helped enable Britain's speedy Covid vaccination drive.