X0306 4 2015-12-01 0 0001326732 Xencor Inc XNCR 0001291972 Baracchini Edgardo Jr C/O XENCOR, INC. 111 WEST LEMON AVENUE MONROVIA CA 91016 0 1 0 0 Chief Business Officer Common Stock 2015-12-01 4 M 0 1250 0.59 A 1250 D Common Stock 2015-12-01 4 S 0 1250 15.9268 D 0 D Stock Option (right to buy) 0.59 2015-12-01 4 M 0 1250 0.00 D 2020-01-17 Common Stock 1250 171921 D Reported transaction occured pursuant to a Rule 10b5-1 Plan adopted March 13, 2015. The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $15.81 to $16.09, inclusive. The reporting person undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth above. 25% of the shares subject to the option vested on the one year anniversary of January 12, 2010 (the "Vesting Commencement Date"), and 1/48th of the shares vest monthly thereafter, such that the option shall be fully vested and exercisable on the four year anniversary of the Vesting Commencement Date. /s/ Lloyd Rowland, Attorney-in-Fact 2015-12-02