Shares in Elan surged by 20% on the Dublin stock market today after the drugs company and its partner for the development of the MS drug Tysabri, Biogen Idec, said a safety study had resulted in no new confirmed cases of the progressive multifocal leukoencephalopathy (PML) brain disease in MS patients.
The two companies have previously reported three confirmed cases of PML, two of which were fatal.
The ongoing safety evaluation in Crohn's disease and rheumatoid arthritis is on schedule to be completed by the end of the summer, the two companies added. They will then make submissions to regulatory authorities in early autumn.
Elan and Biogen also said that the companies are taking preliminary steps to restart clinical trials in MS.
'The findings announced today are an important milestone in understanding the appropriate benefit-risk profit for Tysabri,' commented Lars Ekman, Elan's President of Research and Development.
'Patient safety remains our top priority. We are committed to finalising the safety evaluation for Crohn's disease and rheumatoid arthritis, which is progressing well and on track to be completed by the end of the summer,' he added.
Elan and Biogen suspended Tysabri from the market and halted all clinical trials of the drug in February after the emergence of PML in some of their patients being treated with the drug.
The two companies said today that over 2,000 MS patients from clinical trials were eligible for the safety evaluation. 91% of these patients took part in the review with 99% of them having a neurological exam and 98% having an MRI exam.
Elan shares closed up €1.20 to €7.30 in Dublin.
