(Sharecast News) - AstraZeneca said on Thursday that its investigative drug sipavibart had shown positive results in preventing Covid-19 in vulnerable patients.

The FTSE 100 drugs firm said the phase III pre-exposure prophylaxis trial had met both its primary endpoints, of showing a relative risk reduction of Covid caused by different variants in immunocompromised patients.

AstraZeneca said that while only accounting for around 4% of the population, immunocompromised patients made up around 25% of Covid hospitalisations, ICU admissions and death.

Iskra Reic, executive vice president for vaccines and immune therapies at AstraZeneca, said: "Immunocompromised patients currently have limited or no options for Covid-19 protection, and continue to face a significant burden of disease despite being fully vaccinated.

"We will now work with regulatory authorities globally to bring sipavibart to these vulnerable patients."

The Supernova phase III trial was global, randomised, double-blind and placebo-controlled. It was designed to assess both the safety and efficacy of sipavibart when compared to a control in preventing Covid.

It was carried out across 197 sites in the US, UK, Europe and Asia. A total of 3,335 people took part.