Prime Medicine, Inc.

Forward Looking Statements

This press release contains forward-looking statements within the meaning of the Private Securities Litigation Reform Act of 1995, as amended, including, without limitation, implied and express statements about Prime Medicine’s beliefs and expectations regarding: the continued development and advancement of its WD, AATD and CF programs, including the anticipated timing of filing an IND and/or CTA application for PM647 in 3Q of 2026, the initiation of the global Phase 1/2 clinical trial of PM577a in the second half of 2026, and initial clinical data for PM647 and PM577a in 2027; the potential of Prime Editing to correct the causative mutations of, and to cure, diseases, including WD, AATD, CF and CGD; the ongoing regulatory engagement with the FDA based on the data from its Phase 1/2 trial of PM359 and the outcomes of such engagement, including the planned submission of a BLA filing in H1 2027; the potential benefits of RMAT designation for PM359, including discussions that may support expedited approval and eligibility for rolling and priority review of a future BLA; the effect of the resolution of the arbitration with Beam Therapeutics, Inc. on the Company’s rights to develop and commercialize PM647; the modularity of the Prime Editing platform and the benefits thereof; its expectations regarding the breadth of Prime Editing technology and the implementation of its strategic plans for its business, programs, and technology; and its expected cash runway.

Any forward-looking statements in this press release are based on management’s current expectations and beliefs and are subject to a number of risks, uncertainties and important factors that may cause actual events or results to differ materially from those expressed or implied by any forward-looking statements contained in this press release, including, without limitation, risks associated with: uncertainties related to Prime Medicine’s product candidates entering clinical trials; the authorization, initiation, and conduct of preclinical and IND-enabling studies and other development requirements for potential product candidates, including uncertainties related to opening INDs and obtaining regulatory approvals; risks related to the development and optimization of new technologies, the results of preclinical studies, or clinical studies not being predictive of future results in connection with future studies; the scope of protection Prime Medicine is able to establish and maintain for intellectual property rights covering its Prime Editing technology; Prime Medicine’s ability to identify and enter into future license agreements and collaborations; Prime Medicine’s expectations regarding the anticipated timeline of its cash runway and future financial performance; and general economic, industry and market conditions. These and other risks and uncertainties are described in greater detail in the section entitled “Risk Factors” in Prime Medicine’s most recent Annual Report on Form 10-K, as well as any subsequent filings with the Securities and Exchange Commission. In addition, any forward-looking statements represent Prime Medicine’s views only as of today and should not be relied upon as representing its views as of any subsequent date. Prime Medicine explicitly disclaims any obligation to update any forward-looking statements subject to any obligations under applicable law. No representations or warranties (expressed or implied) are made about the accuracy of any such forward-looking statements.