Shares in Elan edged higher last night after data for its safety evaluation of suspended MS drug Tsyabri was published for the first time in the New England Journal of Medicine.
The medical journal also published full figures from two Phase III clinical trials of the drug - the Affirm standalone trial and the Sentinel study in which the drug was dispensed with
In an editorial, the Journal noted that "by several criteria", the drug, developed by Elan with its US partner Biogen, was an advance over current therapies. The data show that, on its own, Tysabri reduced clinical relapses in MS patients by 68 per cent alongside an 83 per cent fall in the appearance of new or larger brain lesions.
Those figures, which had previously been presented to the international medical community, were better than the significant improvements in efficacy for Tysabri alongside Biogen's existing MS treatment Avonex.
The Journal said the three articles in the periodical published today "extend the efficacy of the drug to the two-year mark and provide reassurance that the risk of PML is small with relatively brief use".
"The available data support the value of natalizumab [ Tysabri] as a potent treatment for multiple sclerosis," the editorial states.
It noted that, while "it is reassuring that no further instances of PML were detected in either of these two large studies, their duration of two years allows only limited inferences".
In a separate development, news agency Bloomberg reported that unpublished research from the University of Texas stating that Tysabri could affect patients' immune cells in a way similar to HIV appeared to have been circulated on Tuesday by a spokesman for a rival MS drug maker, Teva.
The news had knocked Elan's shares back 14 per cent on Tuesday although they recovered some ground later in that session.
Goodbody analyst Dr Ian Hunter yesterday dismissed the report and pointed out that it had yet to be accepted for publication by a scientific journal.
In the US, David Blaustein, a former assistant professor of medicine at Yale who currently manages healthcare investments, said: "This is an immunosuppressant drug and it suppresses the immune system. It [ the Texas research findings] means the drug is working. It doesn't mean Tysabri equals AIDS."
Elan has also announced that trading in its shares will be suspended for the duration of the two-day Food and Drug Administration (FDA) advisory panel meeting next week which will examine the arguments for and against returning Tysabri to the shelves. Biogen has previously announced a similar suspension. - (Additional reporting, Reuters/ LA Times service)
