Kyverna Therapeutics, Inc.

Evaluation of Disclosure Controls and Procedures

Our management, with the participation of our Chief Executive Officer, or the CEO, and Chief Financial Officer, or the CFO (our principal executive officer and principal financial officer, respectively), evaluated the effectiveness of our disclosure controls and procedures as of September 30, 2025. The term “disclosure controls and procedures,” as defined in Rules 13a-15(e) and 15d-15(e) under the Exchange Act, means controls and other procedures of an issuer that are designed to ensure that information required to be disclosed by an issuer 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. Disclosure controls and procedures include, without limitation, controls and procedures designed to ensure that information required to be disclosed by an issuer in the reports that it files or submits under the Exchange Act is accumulated and communicated to the issuer’s management, including its principal executive and principal financial officers, or persons performing similar functions, as appropriate to allow timely decisions regarding required disclosure.

Based on their evaluation, the CEO and the CFO have concluded that our disclosure controls and procedures were not effective as of September 30, 2025, because of the material weaknesses in our internal control over financial reporting described below, which we continued remediating as of September 30, 2025.

A material weakness is a deficiency, or a combination of deficiencies, in internal control over financial reporting, such that there is a reasonable possibility that a material misstatement of annual or interim financial statements will not be prevented or detected on a timely basis.

In connection with our audit of the financial statements for the year ended December 31, 2024, we identified material weaknesses in the design and operating effectiveness of our internal control over financial reporting related to the fact that we did not appropriately design and maintain entity-level controls impacting the control environment, risk assessment, control activities, information and communication and monitoring activities to prevent or detect material misstatements to the financial statements. These material weaknesses related to (i) an insufficient number of qualified resources to ensure adequate oversight and accountability over the performance of controls, including retention of control evidence, (ii) ineffective identification and assessment of risks impacting internal control over financial reporting, and (iii) insufficient evaluation and determination as to whether the components of internal controls were present and functioning based upon evidence maintained for management review controls and activity level controls across substantially all financial statement areas. These material weaknesses continue to exist as of September 30, 2025.

These material weaknesses contributed to the following additional material weakness: we did not design and maintain effective (i) general controls over information systems that support the financial reporting process, (ii) controls over the completeness and accuracy of information used in the operation of control activities across substantially all financial statement areas, and (iii) management review controls at a sufficient level of precision to detect a material misstatement across substantially all financial statement areas that involve complex and judgmental areas of accounting and disclosure.

There were no adjustments that resulted from the above material weaknesses. However, these material weaknesses could result in a misstatement of substantially all of our accounts or disclosures that would result in a material misstatement of our annual or interim financial statements that would not be prevented or detected.

Notwithstanding the material weakness, we believe that the financial statements contained in this Quarterly Report on Form 10-Q fairly present our financial position, results of operations and cash flows for the periods covered by this Quarterly Report on Form 10-Q in all material respects.

Remediation Plans

During the year ended December 31, 2024, and as of September 30, 2025, our management, with the oversight of the Audit Committee of our board of directors, took substantial measures toward remediating the control deficiencies contributing to the material weaknesses described in detail in our Annual Report on Form 10-K for the fiscal year ended December 31, 2024. These remediation efforts have continued during the quarter ended September 30, 2025 and as of the quarter ended September 30, 2025, we have completed the design and implementation of substantially all controls necessary to remediate the material weaknesses previously identified.

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We have hired additional accounting and IT personnel, including but not limited to the hiring of a Vice President of Accounting/Corporate Controller, a Head of Information Technology, and an Assistant Controller;

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We have completed our annual risk assessment and continued to focus on the principles of the Committee of Sponsoring Organizations of the Treadway Commissions, or COSO, framework related to risk assessment;

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We have designed and implemented entity level controls across each of the COSO components necessary for effective internal control;

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We have designed and implemented general controls over information systems across our relevant financial systems;

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We have designed and implemented the necessary management review controls across all financial statement areas;

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We continued to perform manual procedures to validate the completeness and accuracy of certain reports generated from various financial systems that are relevant to the preparation of the financial statements.

However, we have determined that the controls implemented have not operated for a sufficient period of time to fully conclude that the material weaknesses have been remediated as of September 30, 2025. Our management is committed to continuing to make efforts to address each of the identified material weaknesses and believes the measures described above and upon completion of further operation and testing of the required controls will remediate the remaining material weaknesses and strengthen our internal control over financial reporting. This remediation process may require additional resources and will require time to implement. Refer to the "Limitation on the Effectiveness of Controls" section below. We will continue to monitor the effectiveness of these remediation measures.

Changes in Internal Control Over Financial Reporting

Except as discussed above under “Remediation Plans”, there were no other changes in our internal control over financial reporting during the quarter ended September 30, 2025, that have materially affected, or are reasonably likely to materially affect, our internal control over financial reporting.

Limitations on the Effectiveness of Controls

In designing and evaluating the disclosure controls and procedures, management recognizes that because of the inherent limitations in all control systems, no evaluation of controls can provide absolute assurance that all control issues and instances of fraud, if any, within the Company have been or would be detected. These inherent limitations include the realities that judgments in decision-making can be faulty, and that breakdowns can occur because of a simple error or mistake. Additionally, controls can be circumvented by the individual acts of some persons, by collusion of two or more people or by management override of the controls. The design of any system of controls is also based in part upon certain assumptions about the likelihood of future events, and there can be no assurance that any design will succeed in achieving its stated goals under all potential future conditions; over time, controls may become inadequate because of changes in conditions, or the degree of compliance with policies or procedures may deteriorate. In addition, the design of disclosure controls and procedures reflect the fact that there are resource constraints and the benefits of controls and procedures will be considered relative to their costs.