Biogen has confirmed that it will not pursue further development of Tysabri in acute ischemic stroke (AIS) after a mid-stage study missed primary and secondary efficacy goals.

The US biotech said the decision was made after the drug failed to demonstrate an improvement in clinical outcomes - assessed by a composite global measure of functional disability - versus placebo in stroke patients taking part in the Phase IIb ACTION 2 trial.

Both doses of Tysabri (natalizumab) were, however, generally well-tolerated and no new or important safety signals were observed, the firm stressed.

“While we are disappointed with the ACTION 2 study results, we have furthered our knowledge of the disease and will continue to pursue innovative approaches in this area, including BIIB093 (intravenous glibenclamide) for prevention and treatment of edema in large hemispheric infarction, one of the most severe types of stroke,” said Michael Ehlers, executive vice president, R&D at Biogen.

Biogen is planning to initiate a global Phase III study of BIIB093 in individuals with large hemispheric infarction, where brain swelling (cerebral edema) often leads to high morbidity and mortality, in the middle of this year.