(Sharecast News) - Avacta Group has suspended sales of its antigen lateral flow tests, causing the AIM-listed firm's share price to plummet.

The clinical stage biopharma said that while its AffiDX antigen test remained effective at identifying high viral loads of the Omicron variant, its own analysis had shown sensitivity was reduced at lower viral loads.

It has therefore opted to halt sales of the AffiDX test while it replaces the antibody in the product, to ensure its performance with Omicron matches that of previous mutations.

The firm, which specialises in developing targeted cancer therapies as well as diagnostic tests, did not provide a timescale as to when marketing and sales were likely to resume.

As at 1100 GMT, shares in Avacta were down 30% at 82.3p.

Alastair Smith, chief executive, said: "As a responsible business, we set very high standards for ourselves and our products and have continually keep the performance of the AffiDX antigen test under review as new variants have arisen.

"Our determination to only provide high-quality, high-performance diagnostic tests has led us to the correct decision to pause all marketing of the AffiDX lateral flow antigen test.

"We believe Covid-19 testing remains a long-term commercial opportunity."

Avacta - along with a number of other test makers - does not currently sell its products in the UK, because a new review system that came into force in October has yet to grant approval for previously accepted products.