Leqembi — sold through a partnership between Eisai Co. and Cambridge-based Biogen — is one of the first medications approved that promises to slow the speed at which Alzheimer’s erases a person’s memory.

The EU medicines regulator on Friday rejected Eli Lilly's Alzheimer's drug, saying the treatment's ability to slow cognitive decline was not large enough to outweigh the risk of serious brain swelling in patients.

Key regulators are not recommending Lilly’s Kisunla be cleared for the European market. The company says it plans to appeal the verdict, a strategy successfully employed by Eisai.