Avacta reports positive data for Covid-19 test product

Diagnostics and cancer therapies developer Avacta announced positive data from the clinical validation of its ‘AffiDX’ SARS-CoV-2 antigen lateral flow test on Tuesday.

The AIM-traded firm said data from the clinical study conducted in Europe on 98 positive Covid-19 samples demonstrated “excellent performance” in identifying the SARS-CoV-2 virus across a broad range of viral loads.

It said the data would now be combined with stability and other performance data from ongoing studies to finalise the technical file for CE-marking the test for professional use, allowing the company to begin commercial roll-out in Europe in May.

The clinical evaluation of Avacta's lateral flow test was carried out at a single site in Europe, with patient samples with viral loads confirmed by PCR.

Avacta said the study tested 98 positive samples, with the rapid antigen test identifying 96 out of 98 of them correctly as positive, with a 20 minutes read time resulting in a clinical sensitivity of 98.0% for samples within the “broad range”, down to low viral loads.

Out of a total of 102 negative samples tested with the lateral flow device, the test correctly identified 101 as negative, giving a clinical specificity of 99.0%.

Lateral flow rapid antigen tests are intended to provide a low-cost means of identifying individuals with a high viral load that means they are more likely to infect others.

Avacta said a number of factors affect whether an individual would infect others, as well as viral load, such as the circumstances and length of exposure.

However, it noted there was a “growing consensus” that a viral load as measured by PCR of Ct<27 should be considered as infectious.

The clinical data for its AffiDX SARS-CoV-2 antigen lateral flow test demonstrated 100% sensitivity for identifying infectious individuals in that range.

“I am delighted with the clinical data from this larger clinical study, which has robustly evaluated the AffiDX antigen test with lower viral loads of Ct>26 as well as with higher viral load samples,” said chief executive officer Dr Alastair Smith.

“The results are very impressive and mark a major step in obtaining a CE-mark for professional use.

“As part of the study the same clinical samples were tested with two leading, commercially available lateral flow antigen tests, and the data show that the AffiDx test had better clinical sensitivity across the range of Ct value and in particular at lower viral loads.”

Dr Smith said the company was completing the necessary assessment of the product from its manufacturing partner Global Access Diagnostics, including stability testing to complete the technical file for CE-marking, which it expected in early May.

“We are very excited by the potential of this high quality SARS-CoV-2 rapid antigen test and we are looking forward to updating the market as we commercially roll-out the AffiDX test in the coming months.”

At 1501 BST, shares in Avacta Group were up 8.98% at 255.01p.