John Aston was appointed as a non-executive Director of the Company on 23 February 2011 and served as Chairman of the Audit Committee from April 2011 to July 2016. He was subsequently appointed as Chairman of the Company on 12 December 2017. John was chief financial officer of Astex Therapeutics Limited between January 2007 and May 2010, and was chief financial officer of Cambridge Antibody Technology for ten years to 2006. Prior to this he was a director in investment banking with Schroders in London and previously worked for British Technology Group and Price Waterhouse. He is a Chartered Accountant and has a degree in Mathematics from Cambridge University. He has previously been a director of Polar Capital Global Healthcare Trust Plc and a number of private biotech companies.