Passage BIO Inc

Voting Rights; Required Vote

Each holder of shares of common stock is entitled to one vote for each share of common stock held as of the close of business on the Record Date. You may vote all shares owned by you at such date, including (1) shares held directly in your name as the stockholder of record and (2) shares held for you as the beneficial owner in street name through a broker, bank, trustee or other nominee. Dissenters’ rights are not applicable to any of the matters being voted on.

*Stockholder of Record: Shares Registered in Your Name.*If on March 31, 2025, your shares were registered directly in your name with our transfer agent, Computershare Trust Company, N.A., then you are considered the stockholder of record with respect to those shares. As a stockholder of record, you may vote at the Annual Meeting, or vote in advance through the internet or by telephone, or if you request to receive paper proxy materials by mail, by filling out and returning the proxy card.

*Beneficial Owner: Shares Registered in the Name of a Broker or Nominee.*If on March 31, 2025, your shares were held in an account with a brokerage firm, bank or other nominee, then you are the beneficial owner of the shares held in street name. As a beneficial owner, you have the right to direct your broker on how to vote the shares held in your account, and your broker has enclosed or provided voting instructions for you to use in directing it on how to vote your shares. Because the brokerage firm, bank or other nominee that holds your shares is the stockholder of record, if you wish to attend the Annual Meeting and vote your shares, you must obtain a valid proxy from the firm that holds your shares giving you the right to vote the shares at the Annual Meeting.

Each director will be elected by a plurality of the votes cast at the Annual Meeting. This means that the two individuals nominated for election to the board of directors at the Annual Meeting receiving the highest number of “FOR” votes will be elected. You may either vote “FOR” one or both of the nominees or “WITHHOLD” your vote with respect to one or both of the nominees. A “WITHHOLD” will have the same effect as an abstention. You may not cumulate votes in the election of directors. Approval of the ratification of the appointment of our independent registered public accounting firm will be obtained if the number of the votes cast “FOR” the proposal exceeds the number of votes “AGAINST” the proposal. Approval of the amendment to our Restated Certificate of Incorporation will be obtained if the number of the votes cast “FOR” the proposal exceeds the number of votes “AGAINST” the proposal. A proxy submitted by a stockholder may indicate that the shares represented by the proxy are not being voted (stockholder withholding) with respect to a particular matter. In addition, a broker may not be permitted to vote on shares held in street name on non-routine matters in the absence of instructions from the beneficial owner of the stock (broker non-vote). At this meeting, only the ratification of the appointment of KPMG LLP as our independent registered public accounting firm for the fiscal year ending December 31, 2025, is considered a routine matter. The other proposals presented at the Annual Meeting are non-routine matters, and therefore a broker may not vote on such matter absent instructions from the beneficial owner of the stock. The shares subject to a proxy which are not being voted on a particular matter because of either stockholder withholding or broker non-votes will count for purposes of determining the presence of a quorum, but are not treated as votes cast and, therefore, will have no effect on the election of directors or the ratification of the appointment of KPMG LLP. Abstentions will also be counted in the determination of a quorum. Abstentions are voted neither “FOR” nor “AGAINST” a matter, and, therefore, will have no effect on the election of directors or the ratification of the appointment of KPMG LLP. However, an abstention, withholding, broker non-vote or failure to vote will have the same effect as a vote “AGAINST” the amendment to our Restated Certificate of Incorporation.

Recommendations of the Board of Directors on Each of the Proposals Scheduled to be Voted on at the Annual Meeting

The board of directors recommends that you voteFOR the election of each of the Class II directors named in this proxy statement (Proposal 1),FOR the ratification of the appointment of KPMG LLP as our independent registered public accounting firm for the fiscal year ending December 31, 2025 (Proposal 2), andFOR the approval of the amendment to our Restated Certificate of Incorporation (Proposal 3).

None of the directors or executive officers has any substantial interest in any matter to be acted upon, other than elections to office with respect to the directors nominated in Proposal 1.

Voting Instructions; Voting of Proxies

If you are a stockholder of record, you may:

Votes submitted through the internet or by telephone must be received by 11:59 p.m., Eastern Time, on May 27, 2025. Submitting your proxy, whether by telephone, through the internet or by mail if you requested or received a paper proxy card, will not affect your right to vote online should you decide to attend the virtual Annual Meeting.

If you are not the stockholder of record, please refer to the voting instructions provided by your nominee to direct how to vote your shares. If your shares are held in an account with a brokerage firm, bank or other nominee, then you are deemed to be the beneficial owner of your shares and the broker that actually holds the shares for you is the record holder and is required to vote the shares it holds on your behalf according to your instructions. The proxy materials, as well as voting and revocation instructions, should have been forwarded to you by the bank, broker or other nominee that holds your shares. In order to vote your shares, you will need to follow the instructions that your bank, broker or other nominee provides you. The voting deadlines and availability of telephone and Internet voting for beneficial owners of shares held in street name will depend on the voting processes of the bank, broker or other nominee that holds your shares. Therefore, we urge you to carefully review and follow the voting instruction card and any other materials that you receive from that organization.

For Proposal 1, you may either vote “FOR” all of the nominees to the board of directors, or you may withhold your vote from any nominee you specify. For Proposal 2 and Proposal 3, you may vote “FOR” or “AGAINST” or “ABSTAIN” from voting. Your vote is important. Whether or not you plan to attend the Annual Meeting, we urge you to vote by proxy to ensure that your vote is counted.

All proxies will be voted in accordance with the instructions specified on the proxy card. If you sign a physical proxy card and return it without instructions as to how your shares should be voted on a particular proposal at the Annual Meeting, your shares will be voted in accordance with the recommendations of our board of directors stated above.

If you do not vote and you hold your shares in street name, and your broker does not have discretionary power to vote your shares, your shares may constitute “broker non-votes” (as described above) and will not be counted in determining the number of shares necessary for approval of the proposals. However, shares that constitute broker non-votes will be counted for the purpose of establishing a quorum for the Annual Meeting.

If you receive more than one proxy card or Notice of Internet Availability, your shares are registered in more than one name or are registered in different accounts. To make certain all of your shares are voted, please follow the instructions included on each proxy card or Notice of Internet Availability and vote each proxy card by telephone, through the internet or by mail. If you requested or received paper proxy materials by mail, please complete, sign, date and return each proxy card to ensure that all of your shares are voted.

Expenses of Soliciting Proxies

We will pay the expenses associated with soliciting proxies. Following the original distribution and mailing of the solicitation materials, we or our agents may solicit proxies by mail, email, telephone, facsimile, by other similar means, or in person. Our directors, officers and other employees, without additional compensation, may solicit proxies personally or in writing, by telephone, email or otherwise. Following the original distribution and mailing of the solicitation materials, we will request brokers, custodians, nominees and other record holders to forward copies of those materials to persons for whom they hold shares and to request authority for the exercise of proxies. In such cases, we, upon the request of the record holders, will reimburse such holders for their reasonable expenses. If you choose to access the proxy materials and/or vote through the internet, you are responsible for any internet access charges you may incur.

Revocability of Proxies

A stockholder of record who has given a proxy may revoke it at any time before the closing of the polls by the inspector of elections at the Annual Meeting by:

Please note, however, that if your shares are held of record by a brokerage firm, bank or other nominee, and you wish to revoke a proxy, you must contact that firm to revoke or change any prior voting instructions.

Electronic Access to the Proxy Materials

The Notice of Internet Availability will provide you with instructions regarding how to:

Choosing to receive your future proxy materials by email will reduce the impact of our annual meetings of stockholders on the environment and lower the costs of printing and distributing our proxy materials. If you choose to receive future proxy materials by email, you will receive an email next year with instructions containing a link to those materials and a link to the proxy voting site. Your election to receive proxy materials by email will remain in effect until you terminate it.

Voting Results

Voting results will be tabulated and certified by the inspector of elections appointed for the Annual Meeting. The final results will be tallied by the inspector of elections and filed with the SEC in a Current Report on Form 8-K within four business days of the Annual Meeting.

Implications of Being an “Emerging Growth Company” and “Smaller Reporting Company”

We are an “emerging growth company” as that term is used in the Jumpstart Our Business Startups Act of 2012, and a “smaller reporting company” as defined under Rule 405 of the Securities Act of 1933, as amended (the “Securities Act”) and, as such, have elected to comply with certain reduced public company reporting requirements. These reduced reporting requirements include reduced disclosure about the Company’s executive compensation arrangements and no requirement to have non-binding advisory votes on executive compensation.