Avacta Group plc (AIM: AVCT) (“Avacta” or “the Group”), the developer of Affimer® biotherapeutics and research reagents, is pleased to report that the first major immunogenicity study of Affimer technology using human ex-vivo samples has concluded successfully with a range of Affimer proteins shown to have low immunogenicity comparable with the marketed antibody Avastin®.

Unwanted immunogenicity occurs when a patient has an immune response to a drug which can lead to reduced effectiveness of the drug and possibly lead to serious adverse side effects. It is therefore essential that a new drug platform, such as Affimer technology, is shown not to cause a significant intrinsic immunogenic response.

The Company has now completed the first major study of immunogenicity for the Affimer technology using samples from fifty healthy volunteers. Multiple versions of the Affimer technology were tested in the study and benchmarked against the marketed monoclonal antibody Avastin.

All versions of the Affimer scaffold showed a low response in these industry-standard tests comparable to Avastin, confirming that the Affimer technology has no significant immunogenicity.

For further information please download the presentation “Affimer Technology: Results of PBMC Immunogenicity Testing”: https://www.avacta.com/resources/affimer-technology-results-pbmc-immunogenicity-testing

Dr Alastair Smith, Avacta Group Chief Executive Officer, commented: “This excellent data significantly de-risks the Affimer technology as a therapeutic platform addressing the multi-billion dollar biotherapeutics market and is a major milestone and value inflection point for the Company.

Immunogenicity is a key concern for any protein-based therapeutic in development, especially for a new therapeutic platform such as that based on our Affimer technology. I am delighted that the results of this extensive study shows unequivocally that none of the Affimer scaffolds induce a significant immunogenic response. This bodes well for their further development as therapeutics, as there is an accepted correlation between this type of ex-vivo study and a patient’s immunogenic response when dosed with the drug in the clinic.

In the past year the Avacta has hit multiple key milestones for the Affimer technology including successful outcomes of the first in vivo pharmacokinetics and efficacy studies and now the successful outcome of a critical immunogenicity trial. Together this significant progress supports both our conversations with potential pharma partners and our objective to take the first Affimer candidate into clinical development in 2019.”