Xencor (XNCR) 8-K Non-Reliance on Previously Issued Financial Statements or a Related Audit Report or Completed Interim Review

44 Montgomery St Suite 3900 San Francisco, CA 94104 T +1 415 848 5300 F +1 415 848 5353 www.rsmus.com February 13, 2025 Securities and Exchange Commission Washington, D.C. 20549 Commissioners: We have read Xencor, Inc.’s statements included under Item 4.02(b) of its Form 8-K filed on February 13, 2025, and we agree with such statements regarding communications from our firm.