Affimer Binders for Zika Virus Diagnostics

Avacta Rapidly Generates Affimer Binders for Zika Virus Diagnostics

·      Rapid generation and validation of three distinct and highly specific Affimer binders to Zika virus within just thirteen weeks of receiving the virus target.

·      The Affimer reagents bind a protein called NS1 which is diagnostic of the early, acute stage of Zika infection and for which no validated antibody is available.

·      Highlights the potential of Affimer technology to support global rapid response for novel point-of-care diagnostics and health screening.

Wetherby, UK, 22^nd June 2016: Avacta Group plc (AIM: AVCT) ("Avacta" or "the Group"), the developer of Affimer^® biotherapeutics and research reagents, today announced it has identified three Affimer proteins capable of binding to a recombinant form of a secreted Zika virus NS1 protein (Non-Structural protein 1), which is diagnostic of Zika virus infection at the early, acute stage. These Affimer binders were identified and characterised within just thirteen weeks of receiving the virus target and have the potential to be developed into new rapid point-of-care diagnostic tests for Zika infection.

The three Affimer binders are highly specific to the Zika NS1 protein and can differentiate in human serum from five other closely related viruses that give similar symptoms: Dengue, Yellow Fever, West Nile, and Japanese and Tick-borne Encephalitis. Since these viruses are very similar, there is currently no validated antibody that detects Zika virus specifically, which is a limiting factor in the development of a reliable, quick diagnostic test.

The ability to rapidly generate new diagnostic reagents in response to outbreaks of infectious agents is critical to meeting an urgent medical need, as recently evidenced by the SARS and Ebola virus outbreaks. The very high specificity of Avacta's Affimer technology, together with the speed with which new Affimer binders can be identified and characterised, makes the technology ideal for rapidly responding to the need for detection and monitoring of new outbreaks. The Group intends to commercialise Affimer based rapid diagnostics through co-development and licensing to third party diagnostics developers an example of which is Mologic, a UK rapid diagnostics developer, with whom a research and product development collaboration was recently announced.  

Dr Alastair Smith, Chief Executive Officer, Avacta, said: "Avacta's Affimer technology offers a distinct advantage over antibodies in infectious disease diagnostics in terms of both rapid development times and specificity. The identification of these three Affimer binders means that new diagnostic tests could be developed that have the potential to diagnose a Zika infection from its early stages, and would be suitable for low cost, rapid point-of-care diagnostics that could be deployed widely in the field or at US transport hubs for example.

At the half year we set out three initial strategic priorities for the Affimer technology, outside of therapeutic applications, in which we believe that the technology has key competitive advantages. Rapid diagnostics is one of those strategic priorities and the news that we have been able to generate highly specific Affimer binders to a significant emerging health threat in such a short space of time is strong validation of those advantages.

The success of this work shows that the Affimer technology is a platform that can be applied more broadly to generate highly specific binders rapidly. We continue to execute our strategy of developing Affimer reagents for third party products as well as developing our in-house therapeutics pipeline focused on immuno-oncology.  I look forward to the next opportunity to update the market." 

About Zika Virus Diagnostics

The Zika NS1 protein used in the study, together with the other NS1 proteins used for screening, was provided by the Native Antigen Company (https://thenativeantigencompany.com/). This recombinant protein was identified as the best reagent available for the selection of Affimers for Zika diagnostics as it is uniquely produced in mammalian cells, and is therefore chemically and structurally very similar to the native viral antigen. It may also be used as a reference standard in future diagnostic kits.

Existing tests for Zika and the related flaviviruses use PCR to detect the viral DNA or use antigens to detect the patients' own antibodies raised against the viral infection. PCR tests are only effective for a short period of a few days after symptoms begin and detecting the patients' antibodies to the virus only work after the immune response has occurred. These tests suffer from cross reactivity when a patient has been infected in the past with another flavivirus and vaccination against one flavivirus, yellow fever for example, can confound the antibody based tests making it appear that the patient has Zika.  NS1 is a protein that is produced by active flaviviruses from the earliest stages of infection and therefore, if it is possible to differentiate between the different NS1 proteins that are specific to each flavivirus, then an effective and specific diagnostic can be developed. The Affimer binders that have been generated by Avacta make this possible for the first time. 

ENDS

Notes to Editors

For a high resolution image please contact Zyme Communications

For further information from Avacta Group plc, please contact:

About Avacta Group plc (www.avacta.com)

Avacta's principal focus is on its proprietary Affimer^® technology which is a novel engineered alternative to antibodies that has wide application in Life Sciences for diagnostics, therapeutics and general research and development.

Antibodies dominate markets worth in excess of $50bn despite their shortcomings. Affimer technology has been designed to address many of these negative performance issues, principally; the time taken to generate new antibodies, the reliance on an animal's immune response, poor specificity in many cases, and batch to batch variability. Affimer technology is based on a small protein that can be quickly generated to bind with high specificity and affinity to a wide range of protein targets.

Avacta has a pre-clinical biotech development programme with an in-house focus on oncology and bleeding disorders as well as several partnered development programmes. Avacta is commercialising non-therapeutic Affimer reagents through custom Affimer services to provide bespoke solutions to research and diagnostics customers and via a small on-line catalogue of Affimer products.

About The Native Antigen Company (www.thenativeantigencompany.com )

The Native Antigen Company (NAC) specialises in development and manufacture of native and recombinant viral and bacterial antigens. NAC's antigens are used by pharmaceutical and IVD manufacturers in vaccine research and serology where proper folding and glycosylation are vital.

As well as offering antigens from a rapidly expanding portfolio, NAC undertakes bespoke product development and custom manufacture using its proprietary mammalian cell protein expression system