Hemab Therapeutics Holdings, Inc.

Evaluation of Disclosure Controls and Procedures

Our management, under the supervision and with the participation of our Chief Executive Officer and Chief Financial Officer (our principal executive officer and principal financial officer, respectively), evaluated the effectiveness of our disclosure controls and procedures as of June 30, 2026. The term “disclosure controls and procedures,” as defined in Rules 13a-15(e) and 15d-15(e) under the Securities Exchange Act of 1934, as amended, or 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 Securities and Exchange Commission'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.

Management recognizes that any disclosure 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 the evaluation of our disclosure controls and procedures as of June 30, 2026, our Chief Executive Officer and Chief Financial Officer concluded that, as of such date, our disclosure controls and procedures were not effective at the reasonable assurance level because of the material weaknesses in our internal control over financial reporting described below.

In connection with the audit of our consolidated financial statements for the years ended December 31, 2024 and 2025, we identified material weaknesses in our internal control over financial reporting. As defined in the standards of the Public Company Accounting Oversight Board (United States), 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 our annual or interim financial statements will not be prevented or detected on a timely basis.

The material weaknesses were (1) controls around the financial statement close process were not designed or operating effectively, including as a result of an inappropriate segregation of conflicting duties and insufficient evidence of performance and review of controls, and (2) information system controls around user access, segregation of conflicting duties and change management were not designed or operating effectively.

Remediation Plans

To remediate these material weaknesses, we have made and plan to continue to make improvements to the design and operating effectiveness of our internal controls over financial reporting, including the monitoring, oversight and evaluation of our internal controls. We also plan to allocate more internal resources to our internal controls, including by hiring additional staff, and intend to engage external advisors to provide training and to reassess and redesign processes and develop new controls as appropriate, including information technology controls covering access and change management as well as cyber risks, and assisting with the evaluation and documentation of the risk assessment, design and operating effectiveness of our internal controls over financial reporting. See the section titled “Risk Factors—We have identified material weaknesses in our internal control over financial reporting. If we are unable to remedy our material weaknesses, or if we fail to establish and maintain an effective system of internal control over financial reporting, we may be unable to produce timely and accurate financial statements or prevent fraud, which could adversely impact our business and our stock price.”

Changes in Internal Control over Financial Reporting

Except as discussed above under “Remediation Plans”, there were no changes in our internal control over financial reporting (as defined in Rules 13a-15(f) and 15d-15(f) under the Exchange Act) that occurred during the three months ended June 30, 2026 that have materially affected, or are reasonably likely to materially affect, our internal control over financial reporting.