The European Union's drugs regulator on Thursday recommended approval of Eisai and Biogen's Leqembi for some patients with early Alzheimer's disease, reversing its initial decision from four months ago.

Longer-term, Eisai and Biogen are hoping for further evidence to support Leqembi from the phase 3 AHEAD 3-45 trial, which started in 2020 and is underway in Japan, the US, and Europe and is enrolling people ages 55-80 who have not been diagnosed with Alzheimer's or another form of dementia. Results are due in 2028.

Biogen’s stock rose 1% Thursday, after Europe’s pharmaceutical regulator issued a positive opinion on the Alzheimer’s disease drug that the company developed with Japanese partner Eisai — reversing an earlier decision not to approve the drug.