New cases of PML in Tysabri users

Dublin: The latest safety update on the Tysabri multiple sclerosis (MS) drug — co-owned by Elan and US pharma Biogen Idec — has found nine new cases of PML, the potentially fatal brain disease and possible side effect of using the drug, in patients.

There have now been 59 cases of PML, among Tysabri users in Europe, 46 in the US and six in the rest of the world.

Some 20% of those patients have died from the disease.