After Biogen and Eisai's Alzheimer's drug showed strong results in a phase 3 trial in late September, Biogen's shares rose 36 percent and most news outlets reported the results — but don't get too excited about it, researchers told The Wall Street Journal.
Lecanemab — manufactured by Biogen and Eisai, a Tokyo-based pharmaceutical company — recently reduced cognitive decline by 27 percent among patients with mild cognitive impairment or mild Alzheimer's disease in a phase 3 trial. The results showed promise against the backdrop of Biogen's Aduhelm, its older, controversial Alzheimer's drug, and research showing that amyloid plaque buildup isn't the disease's only factor.
Lecanemab is designed to remove aggregated amyloid beta in the brain, which could be a sign of a return to amyloid-focused Alzheimer's drugs. But experts are wary to cast their ballots.
"We still have the whole cliff to climb but at least now, we're on the first ledge," Robert Howard, a professor of old-age psychiatry at University College London, told the Journal about the lecanemab results.
The 27 percent reduction in cognitive decline is a modest result, neurologists and physicians said, and may not be enough to justify the drug compared to its side effects. In the phase 3 trial of 1,795 people, about 12 percent of the study participants who took lecanemab developed swelling and bleeding in the brain, Biogen and Eisai said in a Sept. 27 news release.
"It's not a miracle drug so far, but maybe it's the beginning of something," Nicolas Villain, MD, PhD, an associate professor at Sorbonne University in Paris who studies Alzheimer's, told the Journal.