Avacta Group plc (AIM: AVCT), the developer of Affimer^® biotherapeutics and reagents has announced that the first Affimer-based rapid test strips to detect SARS-CoV-2 spike protein have been developed and evaluated by Avacta’s partners at Cytiva (formerly GE Healthcare Life Sciences) and show positive initial performance data.

In mid-May Avacta provided Affimer reagents that are specific to the SARS-CoV-2 spike protein to Cytiva which has now developed the first lateral flow test strips using these reagents and generated initial performance data using coronavirus spike protein.

These data show that the test strips detect the spike protein in model samples at concentrations within the clinical range found in the saliva of patients with COVID-19. Work continues now to refine the test strip design, optimise its performance and get the best detection limit possible in order to generate the highest sensitivity in the final rapid test product.

According to the WHO, the antigen(s) detected, in this case, the spike protein, are expressed only when the virus is actively replicating; therefore, such tests are best used to identify acute or early infection.

In the absence of independent validation, the WHO has advised against the use of rapid diagnostic tests based on antigen detection in any setting (except research settings), including for decision-making, until evidence supporting their use for specific indications is available. However, due to the overall benefits an accurate test could bring, WHO are 'highly encouraging' research into their performance. 

But in comparison with similar tests used for influenza, the WHO state sensitivity can vary between 34% and 80%.

There are only a few rapid antigen tests with CE-marking on the market but no independent validation exists on these kits. 

Following the optimisation of the lateral flow test by Cytiva the design will then be transferred to manufacturing partners in the UK that are currently being put in place by Avacta. The Company is working with these manufacturers to compress the normal manufacturing, clinical validation and regulatory timelines in order to bring a product to market as quickly as possible.

Avacta have given Medusa19, exclusive rights to global sales and marketing of the kit and non-exclusive rights for its distribution. Medusa19 is a new company set-up by Mahmud Kamani and Richard Hughes, both co-founders of boohoo.com, a popular fashion retail outlet, aimed at the 16-30-year-olds.