Xencor (XNCR) 8-K Changes in Registrant's Certifying Accountant

Exhibit 16.1

	Tel:	(310) 557-0300	1888 Century Park East
	Fax:	(310) 557-1777	4th Floor
	www.bdo.com		Los Angeles, California
			90067

June 26, 2015

Securities and Exchange Commission

100 F Street N.E.

Washington, D.C. 20549

We have been furnished with a copy of the response to Item 4.01 of Form 8-K for the event that occurred on June 24, 2015, to be filed by our former client, Xencor, Inc. We agree with the statements made in response to that Item insofar as they relate to our Firm.

Very truly yours,

/s/ BDO USA, LLP

BDO USA, LLP

BDO USA, LLP, a Delaware limited liability partnership, is the U.S. member of BDO International Limited, a UK company limited by guarantee, and forms part of the international BDO network of independent member firms.

BDO is the brand name for the BDO network and for each of the BDO Member Firms.