Tysabri, withdrawn because of a rare but life-threatening side effect, will return under a restricted distribution programme.
America’s Food and Drug Administration (FDA) said it would let Biogen and Irish-based Elan Corporation resume selling Tysabri under a requirement that doctors, pharmacies and patients register with a programme designed to ensure the safe use of the drug.
The drug was withdrawn from sale in the US last year after three patients who were taking it developed progressive multifocal leukoencephalopathy or PML, a serious disorder of the nervous system. Two of the patients died.
As a result of this, the FDA put clinical trials of the drug on hold in February 2005. However, they allowed a clinical trial to resume in February of this year, following a re-examination of the patients who had participated in the previous clinical trials which confirmed that there were no additional cases of PML.
Prior to the deaths of the patients, Tysabri had been hailed as a wonder drug, as evidence indicated that it reduced the number of relapses and slowed down the progression of MS.
Allen O’Connor of MS Ireland said that the news “offers great hope to those living with relapsing-remitting MS in Ireland and around the world”.
“Tysabri has also received tentative approval by the European Licensing Authority (EMEA). It could be available in Ireland in the near future and this will give people with MS a further option for treating the condition,” Mr O’Connor said.
The FDA said Tysabri is to be used alone in patients who did not respond “adequately” to — or cannot tolerate — other MS drugs.
Researchers have estimated as many as one in every 1,000 Tysabri users might fall prey to the virus that causes PML. Dr Russell Katz of the FDA’s Centre for Drug Evaluation and Research said: “We expect, yes, that there will be other cases and, yes, there will be additional deaths. This is balanced against the significant benefit we believe the drug confers.”
Despite the decision, Elan shares fell 12.4% to €12.93 on the Dublin stock market yesterday.
Anyone with queries on MS can call MS Ireland’s helpline at 1850 233 233 or log onto www.ms-society.ie