Update on Affimer reagent therapy for SARS-CoV-2 infection

Infectivity assays carried out by the Avacta Group in collaboration with the Centre for Virus Research at the University of Glasgow show that the company’s Affimer reagents prevent infection of human cells by a SARS-CoV-2 model virus.

Recently, Avacta reported that several of the Affimer reagents that had been generated to develop SARS-CoV-2 antigen tests inhibited the interaction between the coronavirus spike protein and an angiotensin-converting enzyme 2 (ACE2) receptor found on human cells, which the virus spike protein binds to as the first step in infecting cells.

Avacta has now completed the initial phase of a collaboration with Professor David Bhella at the University of Glasgow showing that these ‘neutralising’ Affimer reagents prevent a SARS-COV-2 model virus from entering human cells and therefore provide a potential therapy for COVID-19 disease.

Affimer reagents have key benefits compared with antibodies as virus neutralising therapies: their small size and high solubility means that a much higher concentration of Affimer molecules can be used in the drug formulation to more effectively block the spike proteins on each virus particle and better protect the patient; bispecific and trispecific Affimer neutralising therapies that bind to more than one part of the spike protein could ensure the effectiveness of the neutralising therapy even if the virus spike protein mutates.