Avacta Group plc announce positive results from the first preclinical in-vivo studies of its therapeutic Affimer molecules. The results meaningfully de-risk the development of the technology as a therapeutic platform; demonstrating that Affimer molecules possess good drug-like properties in terms of efficacy, serum half-life and tolerability.

Two parallel in-vivo pre-clinical studies have been completed. The first, a pharmacokinetics study looking at both human and mouse PD-L1 Affimer inhibitors1engineered as Fc fusions2, showed that Affimer molecules have good in-vivo serum half-lives and are well tolerated at the clinically relevant doses used in the study. 

The second was an efficacy study using a mouse PD-L1 specific Affimer molecule in a syngeneic tumour model3. In this study the Affimer PD-L1 inhibitor produced a statistically significant reduction in tumour growth demonstrating the bioavailability and functionality of the Affimer molecule in tumours in-vivo. No adverse effects were observed.

Alastair Smith, Avacta Group Chief Executive commented: “These results demonstrate that Affimer molecules possess good in-vivo drug-like properties in terms of efficacy, serum half-life and tolerability which is a hugely important milestone in the development and de-risking of the technology as a therapeutic platform. From the initial screening process for the Affimer binders we have been able to rapidly progress to evaluating them in in-vivo models, highlighting another major advantage of the technology. We are very encouraged by these initial positive results and will continue to focus on developing both our internal and partnered therapeutic programs towards clinical validation.”