Shares in pharmaceutical development company Redx Pharma traded at a small premium upon the company's debut on the London Stock Exchange.The Liverpool-based group began trading on AIM on Friday, having raised £15m in gross proceeds after placing 17.6m shares at 85p each.The company, which has nominated Shore Capital as its nominated adviser and broker for its flotation, said its market capitalisation upon admission was approximately £55.2m.Early trades on Friday have seen shares being sold at prices between 86p and 88p."I am delighted that RedX has joined AIM and, at the same time, successfully raised some £15m of new funding," said group chief executive Neil Murray."The company is now embarking on the next stage of its development and we believe that prospects are exciting."In 2014, the company, which was founded four years ago and specialises in new drugs targeted mainly at cancer and infectious diseases, secured a two-year deal with sector giant AstraZeneca for an undisclosed oncology treatment.