Candidate: Affimer® reagents
Type: Non-antibody binding proteins that have been engineered for applications where antibodies and aptamers have limitations.
Status: Avacta Group said July 29 it agreed to expand its collaboration and license agreement with Daewoong Pharmaceutical and AffyXell Therapeutics—the joint venture established in South Korea by the two companies—to develop stem cell treatments incorporating Avacta’s neutralizing Affimer therapy to treat seriously ill patients with COVID-19, and prepare to rapidly develop similar therapies for future global pandemics.
The expanded agreement, whose value was not disclosed, extends the scope of the partnership to include Affimer molecules that target coronaviruses, among other viruses, in order to develop therapies that repair the lung damage caused by COVID-19 while also producing neutralizing Affimer molecules to prevent the progression of the disease.
AffyXell agreed to engineer mesenchymal stem cells to express SARS-COV-2 neutralizing Affimer molecules in order to develop treatments for seriously ill COVID-19 patients. The joint venture also agreed to prepare for rapid development of next-generation stem cell therapies for future infectious respiratory disease outbreaks.
In June, Avacta successfully completed a research collaboration with David Bhella, Professor of Structural Virology at the Centre for Virus Research within the University of Glasgow. The collaboration showed that Affimer reagents that bound to the SARS-COV-2 virus spike protein prevented infection of human cells by a SARS-COV-2 model virus, and thus provide a potential therapy for COVID-19, Avacta asserted.
Prof. Bhella is continuing research to further study how Affimer reagents prevent infection. Avacta said it will use the data to secure “a large pharmaceutical partner to develop these potential therapeutic candidates rapidly.”
In May, Avacta said that several of its Affimer reagents block the interaction between the virus’ spike protein and the ACE2 receptor found on human cells. Avacta said the Affimer reagents have the potential to prevent infection and act as “neutralizing” therapies that could be given to those exposed to the virus (such as health and social-care workers) to prevent infection, as well as to patients already infected by the virus, to help treat and prevent disease progression.
As a result, Avacta said, it is seeking a partner that has the resources to develop a neutralizing Affimer therapy “as quickly as possible.”
Avacta generated the Affimer reagents as part of its partnership with Cytiva (formerly GE Healthcare Life Sciences and now part of Danaher) to develop a rapid point-of-care COVID-19 antigen saliva test to be mass produced for large-scale population screening and for self-testing by consumers. Avacta said June 24 that the first Affimer-based rapid test strips to detect SARS-COV-2 spike protein had been developed and evaluated by Avacta’s partners at Cytiva (formerly GE Healthcare Life Sciences), and showed positive initial results.
Avacta said the Affimer reagents have advantages over antibodies as virus neutralizing therapies: Because of their small size and high solubility Affimer molecules can be used at much higher concentrations to more effectively block the spike proteins on each virus particle and better protect patients. Also, bispecific and trispecific Affimer neutralizing therapies that bind to more than one part of the spike protein could ensure the effectiveness of the neutralizing therapy even if the virus’ spike protein mutates, according to the company.
COVID-19: 200 Candidates and Counting
To navigate through the >200 potential therapeutic and vaccine options for COVID-19, GEN has grouped the candidates into four broad categories based on their developmental and (where applicable) clinical progress:
● FRONT RUNNER – the most promising therapeutics/vaccines based on clinical progress, favorable data or both.
● DEFINITELY MAYBE – earlier phases with promising partners, or more advanced candidates in development that have generated uneven data
● KEEPING AN EYE ON… – interesting technology, attracting notable partners, or both, but preliminary data.
● TOO SOON TO TELL – longshots pending additional experimental and/or clinical data.
GEN has also tagged the most common treatment types: