Researchers return to Alzheimer's vaccines, buoyed by recent drug success

investing.com:

By Julie Steenhuysen

CHICAGO (Reuters) — Breakthrough Alzheimer’s treatments that remove toxic proteins from the brain have revived interest in vaccines to treat the memory-robbing disease, potentially offering a cheaper, easy-to-administer option for millions of people, according to interviews with 10 scientists and company executives.

Clinical trials are underway or completed for at least seven Alzheimer’s vaccines designed to harness the immune system to rid the brain of the disease-related proteins beta amyloid or tau, a review of the U.S. government’s ClinicalTrials.gov database found. More are on the way.

The renewed interest in Alzheimer's vaccines follows a promising first attempt more than 20 years ago that was abandoned after 6% of study volunteers developed life-threatening brain inflammation known as meningoencephalitis.

Researchers then pivoted to a safer route, infusing highly targeted man-made antibodies into patients that sidestep the body’s immune machinery.

Eisai and Biogen (NASDAQ:BIIB)'s newly launched Leqembi and Eli Lilly (NYSE:LLY)'s donanemab, now under U.S. regulatory review, are two such treatments that cemented the view that removing amyloid is key to fighting Alzheimer’s in people with early-stage disease. That success followed years of failures that left many experts questioning the amyloid theory.

Scientists, including those at Vaxxinity, AC Immune and Prothena, believe they now understand what went wrong with the first vaccine and are testing shots they hope will provoke an immune response without causing excess inflammation. The U.S. Food and Drug Administration has given the first two fast-track status, which should speed review of those vaccines.

Dr. Reisa Sperling, an Alzheimer's