GENE therapy company Oxford BioMedica has been given the go-ahead by drug regulators to recruit more volunteers for a clinical trial of a treatment for eye disease.

The trials were halted in June after “low concentrations of a potential impurity” were discovered in the drug.

The company’s share price rose four per cent on the news, having already risen following a million-dollar milestone payment from pharmaceutical giant Pfizer and a £7.1m status recognition award from the UK Government.

BioMedica, based at Oxford Science Park, has used new analytical methods to identify the impurity as DNA from foetal bovine serum, the most widely-used growth supplement in certain laboratory techniques.

Chief executive John Dawson said: “We place the highest importance on safety, and our analytical methods and quality assurance processes are continuously evolving to ensure that we remain at the forefront of gene therapy development and manufacture.

“I’m confident that, with significant opportunities ahead, Oxford BioMedica will continue to lead the way in delivering novel gene therapies to patients.”

The eye treatment uses Biomedica’s LentiVector technology, developed from research at Oxford University by the company’s founders, Professors Alan and Sue Kingsman.

Before resuming the trials in France and the US, the study must be approved by ethics committees following approval by the US Food and Drug Administration and the French regulatory agency, ANSM.

BioMedica had voluntarily stopped recruiting volunteers as a precautionary measure to investigate the material.