X0304 5 2011-12-31 0 1 0001446847 IRONWOOD PHARMACEUTICALS INC IRWD 0001423994 Ridgeback Capital Investments L.P. 430 PARK AVENUE 12TH FLOOR NEW YORK NY 10022 0 0 1 0 0001358916 Ridgeback Capital Investments Ltd. 430 PARK AVENUE 12TH FLOOR NEW YOR, NY 10022 0 0 1 0 0001357610 Ridgeback Capital Management LP 430 PARK AVENUE 12TH FLOOR NEW YORK NY 10022 0 0 1 0 Class B Common Stock 2011-09-22 4 S 0 L 13355 11.10 D 8303710 D Class B Common Stock 2011-09-23 4 S 0 L 8528 11.83 D 8295182 D Class B Common Stock 2011-09-23 4 S 0 L 50000 11.89 D 8245182 D Class B Common Stock 2011-09-26 4 S 0 L 4948 11.79 D 8240234 D Class B Common Stock 2011-09-26 4 S 0 L 50000 11.55 D 8190234 D Class B Common Stock 2011-09-27 4 S 0 L 10132 11.98 D 8180102 D Class B Common Stock 2011-09-27 4 S 0 L 22759 11.55 D 8157343 D Class B Common Stock 2011-10-05 4 S 0 L 49700 10.86 D 8107643 D Class B Common Stock 2011-10-05 4 S 0 L 15017 10.89 D 8092626 D Class B Common Stock 2011-10-06 4 S 0 L 50000 10.91 D 8042626 D Class B Common Stock 2011-10-06 4 S 0 L 12922 10.86 D 8029704 D Class B Common Stock 2011-10-07 4 S 0 L 1600 10.91 D 8028104 D Class B Common Stock 2011-10-10 4 S 0 L 51472 10.98 D 7976632 D Class B Common Stock 2011-10-12 4 S 0 L 5000 11.22 D 7971632 D Class B Common Stock 2011-10-12 4 S 0 L 22330 11.49 D 7949302 D Class B Common Stock 2011-10-13 4 S 0 L 21200 11.84 D 7928102 D Class B Common Stock 2011-10-14 4 S 0 L 38993 12.23 D 7889109 D Class B Common Stock 2011-10-17 4 S 0 L 17122 12.39 D 7871987 D Class B Common Stock 2011-10-21 4 S 0 L 8837 11.85 D 7863150 D Class B Common Stock 2011-10-24 4 S 0 L 26200 11.99 D 7836950 D Class B Common Stock 2011-10-25 4 S 0 L 200000 12.71 D 7636950 D Class B Common Stock 2011-10-26 4 S 0 L 100000 12.85 D 7536950 D Class B Common Stock 2011-10-26 4 S 0 L 34900 13.00 D 7502050 D Class B Common Stock 2011-10-26 4 S 0 L 25000 13.03 D 7477050 D Class B Common Stock 2011-10-27 4 S 0 L 42300 14.28 D 7434750 D Class B Common Stock 2011-10-27 4 S 0 L 160000 13.85 D 7274750 D Class B Common Stock 2011-10-28 4 S 0 L 4100 14.06 D 7270650 D Class B Common Stock 2011-10-31 4 S 0 L 2584 13.81 D 7268066 D Ridgeback Capital Investments L.P. owns all of the securities reported herein directly. Ridgeback Capital Investments Ltd. is the general partner of Ridgeback Capital Investments L.P. Pursuant to an investment management agreement, Ridgeback Capital Management LP maintains investment and voting power with respect to the securities held or controlled by Ridgeback Capital Investments Ltd. Wayne Holman, an individual, controls Ridgeback Capital Management LP. Ridgeback Capital Management LP, Ridgeback Capital Investments Ltd. and Wayne Holman do not own any securities reported herein directly and disclaim beneficial ownership of any of the securities covered by this statement, except to the extent of any pecuniary interest therein. Shares of Class B Common Stock are convertible at any time, at the holder's election, and automatically upon transfer, on a one-for-one basis into shares of Class A Common Stock. Disgorgement of profits is being made by the Reporting Persons to the Issuer. This is 1 of 3 Form 5s being filed. /s/ Bud Holman, Attorney-in-Fact 2012-01-31