Mixed-bag approval hit Sage hard but spared Biogen Sage Therapeutics recently notched an FDA win for the neuroactive steroid zuranolone (Zurzavae) for postpartum depression (PPD). For major depressive disorder (MDD), however, the agency handed the drug a complete response letter. In the wake of the news, Sage’s stock is down 46% to $19.52, while BIIB,…