Is natalizumab a viable treatment for multiple sclerosis?
Natalizumab was predicted to be the leading drug for multiple sclerosis, with estimated annual sales in excess of $2bn (£1.2bn; €1.7bn), but the lack of safety data does not justify its long term clinical use. In a recent murine model of inflammatory colitis, long term treatment with anti-α4 integrin antibodies exacerbated the disease,12 indicating that prolonged blockade of adhesionmolecules prevents migration of lymphocytes, which is essential for viral immunosurveillance.