Biogen in the Drug Discovery & Development Pharma 50Biogen (Nasdaq:BIIB) has terminated a study of the controversial Alzheimer’s disease drug Aduhelm (aducanumab) as a result of limited national policy for coverage.

In a listing on, the company notes that it anticipates there will limited prescriptions of the drug in routine clinical practice, which would provide limited enrollment for the planned ICARE AD study.

The study would have been a prospective, single-arm, multicenter study of aducanumab with up to 5 years of follow-up. The study would have collected data via routine visits every 6 to 12 months, but after opening up recruitment in November, only 29 volunteers had enrolled, according to data posted on

Biogen and its partner Eisai (TYO:4523) announced their plans to launch the observational study in a presentation at the July 2021 Alzheimer’s Association International Conference. The drug had won FDA approval a month earlier.

Biogen still has a Phase 4 confirmatory ENVISION study underway.

BIIB shares were up 2.12%, closing at $211.38.

The so-called amyloid hypothesis initially attracted considerable attention from pharma companies eager to develop drugs that reduce the formation of protein in Alzheimer’s disease patients.

Aducanumab was the first amyloid beta-protein inhibitor to win FDA approval.

Last week, Roche (SIX:RO, ROG; OTCQX:RHHBY) subsidiary Genentech announced disappointing results from a study of a similar drug, crenezumab, which failed to show statistically significant clinical benefit in Alzheimer’s patients.