SHARES in biotechnology firm ReNeuron soared by as much as 30% as the market reacted to positive results from a clinical trial on stem cell therapy for disabled stroke patients.

By the close of trading the stock had fallen back from its earlier highs but was still up 0.4p, or 16%, at 2.85p.

The Pisces study was conducted by a team from Glasgow University at the city's Southern General Hospital and involved stem cells being injected into the brains of those taking part.

Interim data from nine patients is being presented at the European Stroke Conference, which started in London yesterday, by Professor Keith Muir.

The Glasgow University professor will show how some participants regained movement in their limbs and exhibited "modest" reductions in neurological impairment, having had doses of up to 10 million stem cells.

It had been thought recovery was extremely unlikely more than six months on from a stroke, but all the patients participating had their strokes between six months and five years ago.

The Guildford, Surrey, based ReNeuron said none of the patients had experienced any problems with their cells or immune system as a result of the trial.

Two more patients have since been treated with doses of up to 20 million cells and had not experienced any adverse effects.

The full results of the trial are expected to be published next year.

However on the back of the encouraging data an application to go ahead with a further trial of the ReN001 treatment is now planned. Recruitment for that is likely to start in July.

That trial is likely to be with at least 20 patients who have had strokes in recent months and be conducted across multiple sites.

Michael Hunt, chief executive of ReNeuron, said: "This will represent yet another important milestone for ReNeuron, maintaining the Company's pre-eminent position in the development of a neural stem cell-based treatment for disabled stroke patients."