Passage BIO, Inc.

REPORT OF INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM

To the Stockholders and Board of Directors

Passage Bio, Inc.:

Opinion on the Financial Statements

We have audited the accompanying balance sheets of Passage Bio, Inc. (the Company) as of December 31, 2025 and 2024, the related statements of operations and comprehensive loss, stockholders’ equity, and cash flows for the years then ended, and the related notes (collectively, the financial statements). In our opinion, the financial statements present fairly, in all material respects, the financial position of the Company as of December 31, 2025 and 2024, and the results of its operations and its cash flows for the years then ended, in conformity with U.S. generally accepted accounting principles.

Basis for Opinion

These financial statements are the responsibility of the Company’s management. Our responsibility is to express an opinion on these financial statements based on our audits. We are a public accounting firm registered with the Public Company Accounting Oversight Board (United States) (PCAOB) and are required to be independent with respect to the Company in accordance with the U.S. federal securities laws and the applicable rules and regulations of the Securities and Exchange Commission and the PCAOB.

We conducted our audits in accordance with the standards of the PCAOB. Those standards require that we plan and perform the audit to obtain reasonable assurance about whether the financial statements are free of material misstatement, whether due to error or fraud. The Company is not required to have, nor were we engaged to perform, an audit of its internal control over financial reporting. As part of our audits, we are required to obtain an understanding of internal control over financial reporting but not for the purpose of expressing an opinion on the effectiveness of the Company’s internal control over financial reporting. Accordingly, we express no such opinion.

Our audits included performing procedures to assess the risks of material misstatement of the financial statements, whether due to error or fraud, and performing procedures that respond to those risks. Such procedures included examining, on a test basis, evidence regarding the amounts and disclosures in the financial statements. Our audits also included evaluating the accounting principles used and significant estimates made by management, as well as evaluating the overall presentation of the financial statements. We believe that our audits provide a reasonable basis for our opinion.

Critical Audit Matter

The critical audit matter communicated below is a matter arising from the current period audit of the financial statements that was communicated or required to be communicated to the audit committee and that: (1) relates to accounts or disclosures that are material to the financial statements and (2) involved our especially challenging, subjective, or complex judgments. The communication of a critical audit matter does not alter in any way our opinion on the financial statements, taken as a whole, and we are not, by communicating the critical audit matter below, providing a separate opinion on the critical audit matter or on the accounts or disclosures to which it relates.

Evaluation of long-lived assets for impairment

As discussed in Notes 3 and 10 to the financial statements, the Company assesses long-lived assets for impairment whenever events or changes in circumstances indicate that the carrying value of the assets or the asset group may not be recoverable. The Company’s property and equipment, net, and right of use assets – operating leases as of December 31, 2025 were $4.1 million and $10.2 million, respectively. The Company measures the recoverability of assets by comparing the carrying value of the asset groups to an estimate of the related total future undiscounted net cash flows. If an asset group’s carrying value is not recoverable through the related undiscounted net cash flows, the asset group is considered impaired. The Company measures the impairment by comparing the difference between the asset group’s carrying value and its fair value which is

estimated using either an income approach based on the present value of estimated future cash flows or a market approach based on industry and economic conditions including estimates on prevailing prices and rates for similar assets. The approaches are asset group specific and may incorporate a number of market participant assumptions in assessing fair value including future growth rates, discount rates, and market activity. The Company recognized impairment charges for long-lived assets of $6.1 million during the year ended December 31, 2025.

We identified the evaluation of the impairment of an asset group related to the Company’s laboratory space as a critical audit matter. Challenging auditor judgment, and specialized skills and knowledge, were required to evaluate certain assumptions used in the determination of the fair value of the asset group, including sublease market activity and the discount rate.

The following are the primary procedures we performed to address this critical audit matter. We involved valuation professionals with specialized skills and knowledge, who assisted in 1) evaluating sublease market activity used in determining the fair value of the asset group by comparing it to publicly available market data and 2) evaluating the discount rate used by management by comparing it to a range of independently developed discount rates.

/s/ KPMG LLP

We have served as the Company’s auditor since 2019.

Philadelphia, Pennsylvania

March 3, 2026