SHARES IN Elan rose yesterday on reports its Tysabri drug may be able to reverse damage caused by multiple sclerosis (MS), the Irish drugmaker and its US partner Biogen Idec said yesterday. The shares closed in Dublin at €4.47, a gain of 2.55 per cent, having hit €4.86 earlier in the day.

Data released by the companies at the American Academy of Neurology showed that Tysabri promoted the regeneration of the protein coat that protects nerve fibres and whose damage causes the symptoms of multiple sclerosis.

“This provides more evidence that Tysabri may not just slow down the progress of MS but also may be able to reverse the damage caused by the disease,” Goodbody analyst Ian Hunter said in a note.

Tysabri, the fastest-growing drug for Elan and its US partner Biogen Idec, “promoted regeneration and stabilisation of damage done to the myelin sheath”, the coating of nerve fibres that protects nerves in the brain, the Irish company said yesterday.

Tysabri, which is given by infusion, is the most effective drug on the market, reducing the relapse rate in patients with MS by 68 per cent. But sales have been crimped because of its link with progressive multifocal leukoencephalopathy, or PML, a potentially deadly brain infection. The companies have recorded six cases of PML to date.

In the study, magnetic resonance imaging measured lesions and normal brain tissue of 110 patients, 62 of whom received Tysabri for 12 months, compared with 26 who received a standard MS therapy called interferon beta-1a IM, and 22 people in a control group. The findings are being presented at the American Academy of Neurology conference in Seattle.

About 2.5 million people worldwide have MS, a neurological disorder that erodes muscle co-ordination and balance, leading to paralysis and impaired vision in some patients. The disease is the result of the body’s immune system attacking the myelin coating of nerve fibres.

Damage to this sheath causes the symptoms of MS. – (Reuters/ Bloomberg)