10 February 2010 | The risk of developing a potentially deadly brain infection from multiple sclerosis drug Tysabri (natalizumab) increased with the number of infusions received, US drug regulators have warned.
25 January 2010 | The use of multiple sclerosis drug Tysabri (natalizumab) has been backed by a review undertaken in Europe despite continuing concerns about its link to a potentially deadly brain infection.
29 October 2009 | A growing association between a widely used multiple sclerosis drug Tysabri (natalizumab) and a potentially deadly brain infection has been reflected in strengthened warnings for prescribers and patients.
2 July 2009 | Drug regulators are standing by a multiple sclerosis drug that has been associated with a potentially-deadly brain infection.
1 July 2009 | A widely-used multiple sclerosis drug has caused a tenth person to develop a potentially deadly brain infection since being reintroduced three years ago.