Oxford GlycoSciences will be the first Oxfordshire biotech company to develop a new drug and launch it on to the market, following official European approval of its product, Zavesca.

The European Union has given marketing authorisation for Zavesca, a pill to treat the rare genetic disorder Gaucher disease. It is expected to be launched next spring.

The only treatment for Gaucher disease is enzyme replacement therapy (ERT), which is infused into the blood stream.

The European Commission has granted marketing authorisation under exceptional circumstances, on condition that patients are monitored regularly and follow-up safety data is provided.

It can only be given to patients who are not suitable for ERT.

OGS, based at Milton Park, near Abingdon, has asked Swiss company Actelion, which has previous experience of monitoring similar drugs, to market it worldwide, with the exception of Israel, where a separate deal will be reached.

Prof Tim Cox, of Cambridge University, who is vice-president for the European Working Group on Gaucher Disease, said: "Type 1 Gaucher is a debilitating disease and not all patients are suitable for the one currently available therapy, ERT.

"The availability of this first oral treatment is very welcome."

OGS chief executive David Ebsworth said: "We are delighted to receive marketing authorisation for our first drug; this is a major achievement for the company."

Last week, US regulators decided to reconsider Zavesca after initially rejecting it.