(file pics of Lee)MILTON PARK: Steven Lee has quit as chief executive of drug discovery company Summit "to pursue other business opportunities", with Barry Price becoming executive chairman.

Dr Lee has been with the company since 2004, when it was called Vastox. It was spun out of Oxford University's chemistry department to use zebrafish and fruitflies to test potential drugs.

However, last year it ran into financial problems and sold its zebrafish division, and it is now focusing on patents it owns for iminosugars, chemicals found in plants which could be used to treat diabetes and other diseases.

It has enough cash to last until the end of next year, when it expects to start receiving milestone payments from partnerships with bigger drug companies.

Dr Price said: “On behalf of the board, I would like to thank Steven for his considerable effort and commitment during his time with Summit and he leaves with our best wishes for the future."

It is hoping to complete a commercial deal in the first half of next year. It has a £2.2m grant from The Wellcome Trust to develop a drug to treat Clostridium difficile, a superbug which is proving a worse threat to health than MRSA.