With the blockbuster dreams of the Alzheimer’s drug Aduhelm (aducanumab) dashed for the foreseeable future, Biogen has announced that its CEO Michel Vounatsos will depart. Vounatsos began his tenure as CEO in 2017. Vounatsos’ plans to exit the company came out on the same day that Biogen reported Q1 adjusted earnings per share of $3.62,…