Biogen (NSDQ:BIIB) has entered into a licensing agreement with Sage Therapeutics (NSDQ:SAGE) to commercialize zuranolone (SAGE-217) and SAGE-324. It will pay $1.5 billion in addition to potential milestone payments. Zuranolone is an investigational neuroactive steroid that could treat major depressive disorder, postpartum depression, insomnia and other psychiatric disorders. SAGE-324 could potentially treat essential tremor and…