Back in 2018, BAN2401/Aducanumab Phase 2 results were announced by Biogen and Eisai. Here's a couple company news releases. Dig further though and you will find criticism of how they mined the data. Somewhat similar criticism to the Phase 3 results that they'll present this week.

http://investors.biogen.com/news-releases/news-release-details/eisai-and-biogen-announce-detailed-results-phase-ii-clinical

http://investors.biogen.com/news-releases/news-release-details/eisai-and-biogen-announce-presentation-additional-data-phase-ii