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 March 31, 2025, the end of the period covered by this Quarterly Report on Form 10-Q.

Based on such evaluation, the Company’s Chief Executive Officer and Chief Financial Officer have concluded that as of such date, the Company’s disclosure controls and procedures were not effective at the reasonable assurance level due to the material weakness related to the design of controls related to its review of the accounting treatment of the proceeds from the sale of future royalties pursuant to the Ultomiris Royalty Sale Agreement as part of non-routine transactions and the design of controls related to the evaluation of certain tax legislation. These material weaknesses resulted in the restatement of the Company’s consolidated financial statements as of and for the year ended December 31, 2023 and the unaudited consolidated financial statements for each of the first three quarters of 2024. Additionally, these material weaknesses could result in a misstatement of the account balances or disclosures that would result in a material misstatement to the annual or interim consolidated financial statements that would not be prevented or timely detected.

Management’s Plan to Remediate the Material Weaknesses

The Company’s management is committed to maintaining a strong internal control environment. In response to the material weaknesses identified above, management intends to implement comprehensive remediation actions in a timely manner, under the appropriate oversight of the Audit Committee. These actions to remediate the material weakness in internal control over financial reporting include:

(1) Material weakness related to the proceeds from the sale of future royalties

•implementing a more rigorous and structured analysis of non-routine transactions;

•engaging qualified third-party advisors to assist with highly technical and complex accounting transactions; and

•enhancing management’s review of the qualifications and work performed by third-party advisors, specifically in connection with the application of accounting guidance for complex, non-routine transactions.

(2) Material weakness related to the evaluation of certain tax legislation

•enhancing management’s review of the qualifications and work performed by third-party advisors in connection with the review and application of tax advice;

•conducting quarterly reviews of income tax legislative changes and their potential impact on the financial statements in collaboration with tax experts.

The Company believes that the actions outlined above, when fully implemented, will remediate the identified material weaknesses. However, the material weaknesses will not be considered remediated until the applicable controls have operated for a sufficient period of time and management has concluded, through testing, that the controls are operating effectively. Management may also determine that additional measures are necessary to remediate the material weaknesses in the Company’s internal control over financial reporting, which could require additional time for implementation and evaluation. Management will continue to assess the effectiveness of the Company’s internal control over financial reporting and remains committed to remediating the material weaknesses as expeditiously as possible. Management also provides periodic updates on the progress and status of the remediation efforts to the Audit Committee.

Changes in Internal Control over Financial Reporting

Other than the changes associated with the material weakness remediation procedures described above, there have been no changes 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.