X0306 4 2015-03-18 0 0000791908 XOMA Corp XOMA 0001222790 SCANNON PATRICK J MD PHD C/O XOMA CORPORATION 2910 SEVENTH STREET BERKELEY CA 94710 1 1 0 0 Exec. VP & CSO Common Shares 2015-03-18 4 M 0 9500.0 0.0 A 124786 D Common Shares 2015-03-18 4 D 0 3433.0 4.0105 D 121353 D Common Shares 2015-03-18 4 D 0 5233.0 4.0105 D 116120 D Common Shares 25080 I by 401(k) Common Shares 750 I by Daughter Common Shares 4053 I by Trust Restricted Stock Units 0.0 2015-03-18 4 M 0 9500.0 0.0 D 2014-03-18 2016-03-18 Common Shares 9500 9500 D These restricted stock units are scheduled to vest in substantially equal installments annually over three years, with the first installment vesting on March 18, 2014. Each restricted stock unit represents the right to receive, at settlement, one share of common stock. This nondiscretionary transaction represents the settlement of vested restricted stock units in shares of common stock. Shares sold on the open market to satisfy the minimum amount of taxes required to be withheld in connection with the vesting of the shares in a non-discretionary transaction pursuant to the reporting person's agreement under the Company's equity incentive plan. This transaction was executed in multiple trades ranging at prices from $3.93 to $4.15.The price reported reflects the weighted average sale price. The reporting person hereby undertakes to provide upon request to the SEC staff, the Issuer or a security holder of the Issuer full information regarding the number of shares and prices at which the transactions were effected. By: Russell J. Wood For: Patrick J. Scannon, M.D., Ph.D. 2015-03-20