NEW YORK--(BUSINESS WIRE)--Halper Sadeh LLC, an investor rights law firm, is investigating whether the sale of Sage Therapeutics, Inc. (NASDAQ: SAGE) to Supernus Pharmaceuticals, Inc. is fair to Sage shareholders. Under the terms of the proposed transaction, Sage shareholders will receive $8.50 per share in cash, plus one non-tradable contingent value right collectively worth up to $3.50 per share in cash payable upon achieving certain net sales and commercial milestones. Halper Sadeh encourage