Biogen shares fell 1.2% in early trading

Biogen shares fell 1.2% in early trading.A Japanese health ministry panel said on Wednesday that inconsistent trial results made it difficult to determine the efficacy of an Alzheimer's treatment developed by Eisai Co and Biogen Inc.

Tokyo-based Eisai and its United States partner filed for Japanese regulatory approval just over a year ago for the drug Aduhelm, which was approved in the United States in June.

In a statement the panel cited inconsistent results from global Phase III trials and a lack of clinical significance in the drug's ability to reduce plaques in the brain. The panel said it would take another look if further data is submitted.