Tetraphase Pharmaceuticals, Inc. Information Request Form

Levi & Korsinsky, LLP has commenced an investigation into the fairness of the sale of Tetraphase Pharmaceuticals, Inc. (“Tetraphase” or the “Company”) (NASDAQ: TTPH) to AcelRx Pharmaceuticals, Inc. (“AcelRx”) (NASDAQ: ACRX). Under the terms of the merger, Tetraphase stockholders will receive, for each share of Tetraphase common stock, 0.6303 of a share of AcelRx common stock and one contingent value right.

The Tetraphase merger investigation concerns whether the Board of Tetraphase breached their fiduciary duties to stockholders by agreeing to enter into this transaction and whether the merger undervalues Tetraphase relative to AcelRx, thereby harming Tetraphase shareholders.