Shares in pharmaceutical company Elan closed over 10% higher in Dublin today after it presented new research on its multiple sclerosis drug Tysabri yesterday.

The research showed that Tysabri, when used as a stand alone therapy, slowed the progression of multiple sclerosis in patients with the relapsing form of the disease. The data were presented at a meeting of the American Academy of Neurology.

A two year so-called monotherapy trial of the drug, involving 942 patients, concluded that using Tysabri led to a 42% reduction in disability progression.

Tysabri was withdrawn from the market in February, wiping 70% off the value of the company, after it was discovered two patients treated with the drug developed PML, a brain disease. One of the patients died.

The patients were using Tysabri as a combination therapy with another MS drug Avonex. A subsequent trawl through old clinical trial records revealed another Tysabri treated patient also died from PML. Again the patient had been using Tysabri, as a combination therapy, though this time not with Avonex. 

Elan shares closed 30 cent higher at at €3.25 in Dublin this evening.