Biogen Inc. and its Japanese development partner, Eisai, are looking to get their next Alzheimer's drug to market using the U.S. Food and Drug Administration's accelerated approval pathway — the same route they used for Aduhelm, the controversial Alzheimer's drug that was approved last summer. Eisai said in a statement that it has completed its rolling submission for the drug, lecanemab, to the FDA and requested priority review.
Lecanemab is similar to Aduhelm in that it's an antibody that targets clumps of amyloid proteins on the brain. Unlike Aduhelm, though, lecanemab targets a different form of amyloid. The drug is now in Phase 3 trials, with data expected in the third quarter of this year.
The accelerated approval pathway has been at the core of much of the controversy surrounding Aduhelm. In essence, accelerated approval uses what's called a "surrogate endpoint" — in Aduhelm's case, the reduction of amyloid clumps — that is believed to result in a clinical benefit but leaves room for uncertainty. It's not yet known whether reducing those clumps, called amyloid beta plaques, will stop cognitive decline in Alzheimer's patients.