Covid 19 outbreak: Effectiveness of drug uncertain as new variant dominates overseas

Pharmac insists an antibody drug used to treat Covid-19 is useful despite the United States pulling it.

Earlier this week, the US Food and Drug Administration (FDA) announced it was revoking emergency authorisation of antibody drugs, including one Regeneron and Roche developed known as Regen-Cov in the US and Ronapreve in New Zealand.

Regeneron last month warned that laboratory testing suggested the treatment would be much less potent against Omicron, which now makes up more than 99 per cent of infections in the US.

The antibody drug Regeneron is referred to as Ronapreve in New Zealand. Photo / AP

However, Pharmac's chief medical officer Dr David Hughes said because Delta was still present in the community in New Zealand, Ronapreve will still be used here.

In a statement yesterday, Pharmac announced Ronapreve and other drugs will be available for use in DHB hospitals from February 1.

"Ronapreve can also be used in hospital for patients with Covid-19 who have mild to moderate symptoms and are at high risk of progressing to severe disease," Hughes said.

Hughes said reports showed Ronapreve was successful in treating those with the Delta variant and that Delta was still prevalent in New Zealand.

"While the focus is understandably shifting to Omicron, Delta has not disappeared. Delta is still around, and it is still the dominant form of COVID-19 in many countries," he told the Herald.

Ronapreve belongs to a class of medicines called monoclonal antibodies, or mAbs.

They mimic the natural antibodies that the immune system makes to fight disease. Pharmac has secured enough Ronapreve to treat 5300 people, with "medium-to-severe" symptoms.

While the evidence is less clear and still emerging for its use in treating Omicron, Hughes said Pharmac was continuing to work as quickly as possible to assess the latest evidence as it becomes available.

Hughes said getting vaccinated and boosted remained the best defence against Covid-19.

Medsafe acting group manager Derek Fitzgerald said they were aware of the change in recommendations by the FDA and that "Medsafe is following usual, best practice on this matter by obtaining more information".