I can think of 3 scenarios. 1) Arena has some good news and wants to share it sooner. or 2) Arena and Eisai want to release earnings simultaneously to make things easier. or 3) Eisai has good news, but Arena has bad news and is hoping to ride Eisai's good news.
Doesn't mean anything! Having followed Arena since 2006, the dates of their earning CC's means squat.
You are doing a disservice with this post setting expectations for something that won't probably happen.
Besides the earnings and giving updates on the Bel Phen study progress with the FDA; guidance for the rest of the year, etc. There won't be any partnerships, Swiss approval or anything material like that. Truly material items get announced as they occur.
Sentiment: Strong Buy