Avacta Group plc (LON:AVCT), the developer of Affimer biotherapeutics and reagents, has announced that a BAMSTM diagnostic test for the COVID-19 infection, being developed with its partner Adeptrix (Beverly MA, USA), has reached prototype stage and can detect the coronavirus spike protein in model samples in the concentration range appropriate for a clinical diagnostic test.
The bead-assisted mass spectrometry (“BAMS”) assay uses the Affimer reagents specific to the SARS-COV-2 virus recently developed by Avacta to capture the virus spike protein from the sample for rapid detection by mass spectrometry.
A prototype assay has now been developed and evaluated by Adeptrix using model samples containing the coronavirus spike protein. The unique method breaks up the spike protein captured from the samples by Affimer coated beads and is able to identify fragments of the spike protein using mass spectrometry, at concentrations in the range found in patient samples generated from standard throat swabs.
The combination of the selectivity of the Affimer reagents used to capture the virus spike protein with the precision and accuracy of mass spectrometry detection provides for a very high degree of specificity in the assay.
The next step in the development of the final product to run on the installed base of mass spectrometers in clinical laboratories around the world is to evaluate and optimise the BAMS assay using patient samples at laboratory sites in the UK and US which will be done imminently before moving to manufacturing, clinical validation to quantify the sensitivity and specificity and CE/FDA approval for professional use in the summer.
Dr Alastair Smith, Chief Executive Officer of Avacta Group, commented:
“I am very pleased with the rapid progress made by our partners at Adeptrix and delighted that the Affimer reagents that we have developed to detect the SARS-COV-2 spike protein are working very well in the BAMS assay. This bodes well for all our COVID-19 antigen test development programmes.
We are now looking forward to testing the prototype BAMS assay with patient samples in the UK very soon, whilst Adeptrix does the same at a site in the US. This will keep us on track for launch of a product for professional use in the summer.
A COVID-19 BAMS assay could provide highly sensitive and specific testing for up to a thousand samples per day in the hospital setting using standard equipment that is available but not currently used for coronavirus testing thus contributing significantly to an increase in global testing capacity.
We continue to make very good progress with Cytiva on the saliva-based antigen test and I look forward to updating the market soon on both of these product developments as well as future additional partnerships.”
Dr. Jeffrey C. Silva, Director of Product Development, Adeptrix Corporation commented:
“We are excited to apply Avacta’s Affimer reagents to monitor COVID-19 infection because they are very well suited for large-scale manufacturing and have stable lot-to-lot performance due to it being a recombinant technology.
The BAMS assay for the spike protein serves as a useful diagnostic tool because this particular viral protein is displayed on the surface of the virus particle and directly involved in engaging host cells (via ACE2 receptor) during infection. For this reason, the same BAMS assay for the spike protein can also be used for drug development efforts to screen compounds that block interaction with host cells through the ACE2 receptor to prevent virus infection.
Future work will include testing Affimer reagents to other SARS-COV-2 antigens, such as nucleocapsid protein. Diagnostic assays to nucleocapsid protein may enhance sensitivity for detection of COVID-19 infection, since this is a highly abundant viral protein.
Expanding detection to other SARS-COV-2 antigens will enable configuration of a multiplexed BAMS assay to simultaneously monitor multiple viral proteins for added specificity in the case of future pandemics. The precision and accuracy of mass spectrometry detection using the BAMS assay platform will allow researchers to monitor molecular changes that may occur through natural evolution of the virus.”
