Xencor Inc

Evaluation of Disclosure Controls and Procedures

The Company’s management, with the participation of its Chief Executive Officer and Chief Financial Officer (its principal executive officer and principal financial officer, respectively), evaluated the effectiveness of the Company’s disclosure controls and procedures (as defined in Rules 13(a)- 15(e) and 15(d)- 15(e) under the Securities Exchange Act of 1934, as amended), as of December 31, 2025, the end of the period covered by this Annual Report on Form 10-K.

Disclosure controls and procedures include, without limitation, controls and procedures designed to ensure that information required to be disclosed by the Company in the reports that it files or submits under the Exchange Act is recorded, processed, summarized, and reported within the time periods specified in the SEC’s rules and forms, and that such information is accumulated and communicated to management, including the Company’s principal executive and principal financial officers, as appropriate to allow timely decisions regarding required disclosure. Management recognizes that any controls and procedures, no matter how well designed and operated, can provide only reasonable assurance of achieving their objectives, and management necessarily applies its judgment in evaluating the cost-benefit relationship of possible controls and procedures.

Based on such evaluation, the Company’s Chief Executive Officer and Chief Financial Officer concluded that, as of December 31, 2025, the Company’s disclosure controls and procedures were effective at the reasonable assurance level.

Management’s Annual Report on Internal Control over Financial Reporting

Management is responsible for establishing and maintaining adequate internal control over financial reporting for the Company. Internal control over financial reporting is defined in Rules 13a-15(f) and 15d-15(f) promulgated under the Securities Exchange Act of 1934, as amended, as a process designed by, or under the supervision of, the Company’s principal executive and principal financial officers, and effected by the Company’s board of directors, management and other personnel, to provide reasonable assurance regarding the reliability of financial reporting and the preparation of financial statements for external purposes in accordance with GAAP.

Internal control over financial reporting includes those policies and procedures that:

•Pertain to the maintenance of records that, in reasonable detail, accurately and fairly reflect the transactions and dispositions of the Company’s assets;

•Provide reasonable assurance that transactions are recorded as necessary to permit preparation of financial statements in accordance with GAAP, and that the Company’s receipts and expenditures are being made only in accordance with authorizations of management and directors; and

•Provide reasonable assurance regarding prevention or timely detection of unauthorized acquisition, use or disposition of the Company’s assets that could have a material effect on the financial statements.

Because of its inherent limitations, internal control over financial reporting may not prevent or detect all misstatements. Projections of any evaluation of effectiveness to future periods are subject to the risk that controls may become inadequate because of changes in conditions, or that the degree of compliance with the policies or procedures may deteriorate.

Management assessed the effectiveness of the Company’s internal control over financial reporting as of December 31, 2025. In making this assessment, management used the criteria set forth by the Committee of Sponsoring Organizations of the Treadway Commission (COSO) in Internal Control – Integrated Framework (2013). Based on this assessment, management concluded that the Company’s internal control over financial reporting was effective as of December 31, 2025. Management believes that the material weaknesses previously disclosed in prior periods have been fully remediated.

The effectiveness of the Company’s internal control over financial reporting as of December 31, 2025 has been audited by KPMG LLP, an independent registered public accounting firm, as stated in its attestation report, which is included herein.

Changes in Internal Control over Financial Reporting

Except as described below, there has been no change in the Company’s internal control over financial reporting during the Company’s most recent fiscal quarter that has materially affected, or is reasonably likely to materially affect, the

Company’s internal control over financial reporting. The Company regularly evaluates its controls and procedures and makes improvements in the design and effectiveness of established controls and procedures and the remediation of any deficiencies which may be identified during this process.

Remediation of Prior Material Weakness

As previously disclosed in the Company’s Annual Report on Form 10-K for the year ended December 31, 2024, the Company identified material weaknesses related to (i) the design of controls related to the review of the accounting treatment of the proceeds from the sale of future royalties as part of the Company’s non-routine transactions analysis and (ii) the design of controls related to the evaluation of certain tax legislation.

During 2025, the Company implemented a remediation plan and several changes to its internal control environment to address these material weaknesses. Specifically, the Company:

Non-Routine Transactions: Implemented a more rigorous technical analysis of non-routine transactions and enhanced the process to identify, select, and oversee qualified third-party advisors on highly technical and complex accounting matters, including circumstances where management’s supervision and review controls over significant and unusual transactions require enhanced oversight.

Tax Legislation: Enhanced the internal review of work performed by third-party tax advisors and established a formal quarterly process to review income tax legislative changes and their specific impacts on the consolidated financial statements with tax experts.

Based on the Company’s testing of the operating effectiveness of these newly implemented controls, the Company has concluded that these material weaknesses have been remediated as of December 31, 2025.