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 2011-08-02 4 S 0 L 94600 15.20 D 9794662 D Class B Common Stock 2011-08-02 4 S 0 L 2300 15.39 D 9792362 D Class B Common Stock 2011-08-02 4 P 0 L 1000 15.12 A 9793362 D Class B Common Stock 2011-08-03 4 S 0 L 59049 15.27 D 9734313 D Class B Common Stock 2011-08-03 4 S 0 L 226200 15.09 D 9508113 D Class B Common Stock 2011-08-04 4 S 0 L 75000 15.00 D 9433113 D Class B Common Stock 2011-08-04 4 S 0 L 25000 15.10 D 9408113 D Class B Common Stock 2011-08-04 4 S 0 L 25600 15.01 D 9382513 D Class B Common Stock 2011-08-05 4 S 0 L 10000 14.55 D 9372513 D Class B Common Stock 2011-08-05 4 S 0 L 50000 14.00 D 9322513 D Class B Common Stock 2011-08-08 4 S 0 L 108200 12.44 D 9214313 D Class B Common Stock 2011-08-09 4 S 0 L 99700 12.42 D 9114613 D Class B Common Stock 2011-08-09 4 S 0 L 42812 12.44 D 9071801 D Class B Common Stock 2011-08-09 4 S 0 L 32372 12.49 D 9039429 D Class B Common Stock 2011-08-11 4 S 0 L 39600 12.54 D 8999829 D Class B Common Stock 2011-08-15 4 S 0 L 1400 13.02 D 8998429 D Class B Common Stock 2011-08-15 4 S 0 L 12765 12.96 D 8985664 D Class B Common Stock 2011-08-17 4 S 0 L 250000 13.00 D 8735664 D Class B Common Stock 2011-08-18 4 S 0 L 99000 12.45 D 8636664 D Class B Common Stock 2011-08-18 4 P 0 L 1000 12.42 A 8637664 D Class B Common Stock 2011-08-19 4 S 0 L 93600 12.23 D 8544064 D Class B Common Stock 2011-08-22 4 S 0 L 70000 12.44 D 8474064 D Class B Common Stock 2011-08-23 4 S 0 L 31352 13.05 D 8442712 D Class B Common Stock 2011-08-23 4 S 0 L 500 13.04 D 8444212 D Class B Common Stock 2011-08-25 4 S 0 L 80000 12.71 D 8362212 D Class B Common Stock 2011-08-26 4 S 0 L 25000 12.82 D 8337212 D Class B Common Stock 2011-08-26 4 S 0 L 47 13.00 D 8337165 D Class B Common Stock 2011-08-30 4 S 0 L 20100 12.75 D 8317065 D Class B Common Stock 2011-08-30 4 P 0 L 100 12.75 A 8317165 D Class B Common Stock 2011-08-30 4 S 0 L 100 12.82 D 8317065 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