Avacta Group, a biopharma developing cancer therapies and diagnostic tools, has provided an update on the performance of the AffiDX SARS-CoV-2 antigen lateral flow test (LFT) with the Omicron variant.
The performance of rapid antigen tests has recently come under scrutiny following several mutations in the Omicron variant of the SARS-CoV-2 virus. The FDA, as well as other sources, has indicated antigen tests can detect the Omicron variant but may have reduced sensitivity.
As reported on 15 December 2021, the AffiDX SARS-CoV-2 antigen test has been shown to detect the Omicron variant of the SARS-CoV-2 virus in patient samples in a small clinical study. While the test is effective at identifying high viral loads of Omicron, further laboratory analysis carried out by the company indicates the sensitivity of the test is reduced at lower viral loads when compared to previous SARS-CoV-2 variants.
The AffiDX SARS CoV-2 antigen lateral flow test contains both a proprietary Affimer reagent and a commercially available antibody. The company’s data shows the Affimer reagent in the AffiDX test detects the Omicron variant with the same sensitivity as the Delta variant, and it’s the performance of the antibody, with which the Affimer is paired in the test, that has been affected by the additional mutations. The company has taken the decision to pause sales of the AffiDX antigen test while it replaces the antibody in the product to ensure its performance with the Omicron variant matches that of the previous mutations.
Dr Alastair Smith, Chief Executive of Avacta Group, commented: ““The continued high performance of the Affimer reagent in the AffiDX antigen test, despite the large number of mutations in the Omicron variant, is testament to the robustness of our platform technology.”
“As a responsible business, we set very high standards for ourselves and our products and have continually kept the performance of the AffiDX antigen test under review as new SARS-CoV-2 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 have, of course, been unable to market the product in the UK since October 2021, as the product continues to await approval under the new CTDA regulatory process.”