[By NBC-1TV H. J Yook]Synergy Pharmaceuticals Inc. (Nasdaq:SGYP), a developer of new drugs to treat gastrointestinal disorders and diseases, today announced that its previously announced merger with Callisto Pharmaceuticals, Inc. (formerly OTC QB: CLSP) closed effective today.

Under the terms of the merger agreement, as amended, each outstanding share of Callisto common stock was converted into the right to receive 0.1799 of one share of Synergy common stock and the approximately 22.3 million shares of Synergy held by Callisto were canceled. Consequently, effective as of the close of business today, Callisto's common stock will no longer be traded on the OTC QB.

Each share of Synergy common stock received in connection with the merger will be subject to a lock-up beginning January 17, 2013 and ending on the earlier of (i) January 17, 2015, (ii) a Change in Control of Synergy (as defined in the merger agreement), or (iii) written consent of Synergy, at Synergy's sole discretion, provided that such consent shall apply to all shares issued pursuant to the merger.

Philadelphia Stock Transfer, Inc., Synergy's transfer agent, will mail letters of transmittal to all Callisto stockholders of record immediately prior to the merger with instructions on how to deliver their stock certificates in exchange for the merger consideration. Callisto stockholders should not surrender their stock certificates until they have completed the letter of transmittal. Callisto stockholders who held their shares in “street name” through a bank or broker should contact their bank or broker to determine what actions they must take to receive the merger consideration.