Another Alzheimer's drug disappoints

Hopes for new Alzheimer's drugs took another disappointing turn Thursday, when Roche said an antibody therapy in a long-running trial didn't help people with a rare genetic condition that causes early-onset Alzheimer's.

The big picture: The news comes just weeks after the crash of Biogen's heavily touted Aduhelm — another Alzheimer's drug that targets a brain plaque called amyloid thought to contribute to the condition.

Where it stands: Roche said Thursday that its treatment crenezumab didn’t slow or prevent cognitive decline in 252 members of an extended family in Colombia who carry a mutation that typically causes impairment to begin around age 44.

• The trial launched in 2012 and measured results over five to eight years.

Go deeper: Billions of dollars in drug development have been built around the theory that brain amyloid plaques are major contributors to Alzheimer's and that reducing those plaques will fight the disease.

• FDA guidance on Alzheimer's drug development states "there is unfortunately at present no sufficiently reliable evidence that any observed treatment effect on such biomarker measures," like lowering amyloid levels, "would be reasonably likely to predict clinical benefit."
• Researchers say crenezumab's failure to slow the disease in a specific population doesn't necessarily rule out other antibody treatments.

What's next: The National Institute of Aging, which funded the Roche study, said data collected in Colombia that will be presented at a conference in August may influence how amyloid is studied as a target going forward.

• Some researchers have advocated a broader approach to target underlying pathologies of Alzheimer's and to better understand the role aging plays in the condition.
• "I think we need to manage our expectations," said Howard Fillit, co-founder and chief science officer of the Alzheimer's Drug Discovery Foundation. "It's becoming increasingly clear that aging is the leading risk factor for Alzheimer's disease, so we need to apply our understanding from 100 years of research."