The effectiveness of Elan and Biogen drug Tysabri in Crohn's disease is not clearly different from other approved therapies, US drug reviewers said in documents released today ahead of an advisory panel meeting.
The companies are seeking approval to market the multiple sclerosis (MS) drug for Crohn's, a bowel disorder.
US Food and Drug Administration staff said there may be some Crohn's patients for whom Tysabri's risks, which include a rare and serious brain infection, may be more acceptable.
The FDA will ask a panel of outside advisers on Monday if Tysabri should be approved for Crohn's disease. The agency usually follows panel recommendations.
'The benefit and risk considerations in the (Crohn's) population are considerably different from those in the MS population,' FDA reviewers said.
'The treatment effect in the (Crohn's) population ... was not as high as that in the MS population ... nor is it clearly distinguished' from approved Crohn's therapies, they added.
The FDA reviewers said Biogen has not performed all of the desired analyses to help determine if certain patients may be more at risk for complications.
In a separate summary, Biogen said Tysabri was a 'highly effective' treatment for Crohn's disease and risks could be minimised through label warnings, a controlled distribution system and other measures.
