X0306 4 2015-08-25 1 0001463729 Receptos, Inc. RCPT 0001051411 MAST ERLE T C/O RECEPTOS, INC. 3033 SCIENCE PARK ROAD, SUITE 300 SAN DIEGO CA 92121 1 0 0 0 Common Stock 2015-08-25 4 U 0 300 D 7400 D Common Stock 2015-08-27 4 D 0 7400 D 0 D Stock Option (right to buy) 18.77 2015-08-27 4 D 0 18800 213.23 D 2023-07-16 Common Stock 18800 0 D Stock Option (right to buy) 27.44 2015-08-27 4 D 0 9400 204.56 D 2024-06-02 Common Stock 9400 0 D Pursuant to the terms of the Agreement and Plan of Merger (the "Merger Agreement"), dated as of July 14, 2015, by and among Receptos, Inc., a Delaware corporation (the "Company"), Celgene Corporation, a Delaware corporation ("Parent"), and Strix Corporation, a Delaware corporation and a wholly owned subsidiary of Parent, the reporting person disposed of 7,700 shares of the Company's common stock in the merger and Offer (as defined in the Merger Agreement) in exchange for $232.00 per share in cash (the "Offer Price") which number includes 7,400 unvested time-based restricted stock units. Pursuant to the terms of the Merger Agreement, each stock option of the Company, whether vested or unvested, was cancelled in exchange for a cash payment with respect thereto equal to the product of (A) the excess, if any, of (1) the Offer Price over (2) the exercise price per share of such option, and (B) the number of shares of common stock underlying such option. The original vesting term of the option was as follows: the option vested in 36 equal monthly installments commencing on July 17, 2013. The original vesting term of the option was as follows: the option vested in 12 equal monthly installments commencing on June 3, 2014. /s/ Erle T. Mast, by Christian Waage, Attorney-in-Fact 2015-08-27