1 Delivering on the promise of Prime Editing July 2025 Corporate Presentation

2 This presentation contains forward-looking statements of Prime Medicine, Inc. ("Prime", "we" or "our") within the meaning of the Private Securities Litigation Reform Act of 1995, as amended. These forward-looking statements contain information about our current and future prospects and our operations, which are based on currently available information. All statements other than statements of historical facts contained in this presentation, including statements regarding our strategy, projects and plans are forward-looking statements. In some cases, you can identify forward-looking statements by terminology such as “aim,” “anticipate,” “assume,” “believe,” “contemplate,” “continue” “could,” “design,” “due,” “estimate,” “expect,” “goal,” “hope,” “intend,” “may,” “might,” “objective,” “opportunity,” “plan,” “predict,” “positioned,” “possible,” “potential,” “project,” “seek,” “should,” “strategy,” “target,” “will,” “would” and other similar expressions that are predictions of or indicate future events and future trends, or the negative of these terms or other comparable terminology. These forward-looking statements include, but are not limited to, express or implied statements about Prime’s beliefs and expectations regarding: the potential of Prime Editing to correct the causative mutations of diseases, including CGD, Wilson’s Disease, CF, and AATD; the continued development and advancement of its AATD and Wilson’s Disease programs, including the timing of the filing of IND and/or CTA applications in mid-2026 and 1H 2026, respectively, and the timing of initial data for both programs in 2027; the initiation, timing, progress and results of our research and development programs, preclinical studies and future clinical trials, including the release of data related thereto; the safety profile of Prime Editing, our modular LNP, and our programs; our ability to launch therapeutics; the timing of, and our ability to achieve, clinical validation and sustained, long-term value creation; the modularity of the Prime Editing platform and the benefits thereof; the collaboration with Bristol Myers Squibb and the intended and potential benefits thereof, including the receipt of potential milestone and royalty payments from commercial product sales, if any; the 2025 agreement with the Cystic Fibrosis Foundation ("CF Foundation"), its expanded funding pursuant thereto, and the intended and potential benefits thereof, including the receipt of payments based on scientific milestones; our expectations regarding the breadth of Prime Editing, including the potential of Prime Editing to address more than 90% of genetic diseases and to address non-genetic diseases; the continued development and optimization of various non-viral and viral delivery systems, including our universal liver-targeted LNP delivery approach; the scope of protection we are able to establish and maintain for intellectual property rights covering our Prime Editing technology; the implementation of our strategic plans for our business, programs and technology, including our ability to maintain collaborations or strategic relationships and identify and enter into future license agreements and collaborations; regulatory developments in the United States and foreign countries; developments related to our competitors and our industry; our ability to attract and retain key scientific and management personnel; our estimates of our expenses, capital requirements, and needs for additional financing; and our expectations regarding the anticipated timeline of our cash runway and future financial performance. Actual results or events could differ materially from the plans, intentions and expectations disclosed in the forward-looking statements we make due to a number of risks and uncertainties. These and other risks, uncertainties and important factors are described in the section entitled "Risk Factors" in our most recent Annual Report on Form 10-K, as well as any subsequent filings with the Securities and Exchange Commission. Any forward- looking statements represent our views only as of the date of this presentation and we undertake no obligation to update or revise any forward-looking statements, whether as a result of new information, the occurrence of certain events or otherwise subject to any obligations under applicable law. We may not actually achieve the plans, intentions or expectations disclosed in our forward-looking statements, and you should not place undue reliance on our forward-looking statements. No representations or warranties (expressed or implied) are made about the accuracy of any such forward-looking statements. Certain information contained in this presentation relates to or is based on studies, publications, surveys and other data obtained from third-party sources and our own internal estimates and research. While we believe these third-party studies, publications, surveys and other data to be reliable as of the date of this presentation, we have not independently verified, and make no representation as to the adequacy, fairness, accuracy or completeness of, any information obtained from third-party sources. In addition, no independent source has evaluated the reasonableness or accuracy of our internal estimates or research and no reliance should be made on any information or statements made in this presentation relating to or based on such internal estimates and research. Forward Looking Statements

3 We are advancing Prime Editing to change the course of how diseases are treated. We aim to provide safe, effective and curative treatments, which offer lifelong benefit to patients.