Elan’s multiple sclerosis drug Tysabri received a boost today when European regulators approved updated labelling.
The addition of a warning citing an additional risk factor, anti-JC virus antibody status, is seen as allowing doctors to assess more accurately patients for suitability for treatment with the drug.
The drug will now list presence of the virus antibodies alongside prior treatment with immunisuppressants and length of time on Tysabri therapy as risk factors.
A test to determine whether a patient has the JC virus has been developed by Elan and its US partner, Biogen, and is expected to be commercially available in the key US market by the middle of the year, according to a spokeswoman for the Irish company. It is currently being used in clinical trials.
The test has been available in Europe since March, initially on a phased basis. Elan said it should be routinely available by mid-year.
The major concern about Tysabri has been the onset of a potentially fatal brain condition, progressive multifocal leukoencephalopathy (PML). However, all incidences of the disease to date have occurred in people with the JC virus – a group which accounts to just over half the MS populaiton.
Patients testing negative for JC virus are therefore seen as being able to take the drug - still considered the most effective MS treatment in the market – without the threat of contracting the disease.
Deutsche Bank analysts Richard Parkes said today's approval by the Committee for medicinal Products for Human Use was roughly six months ahead of projections .
“We view this as a meaningful positive for Elan/Biogen’s efforts to convince physicians and patients of the utility of the assay,” he wrote in a note to clients.
He noted that Tysabri is currently used by just under 10 per cent of MS patients. “This compares with a theoretical 40-50 per cent patients who are expected to be JC virus negative and hence are presumed to have a significantly lower risk of PML.”
This, he said, would allow the companies for the first time to market the benefits of the drug to people with a “presumed lowerr risk” of PML.
Elan will report figures for its fiscal first quarter on Wednesday.
