Prime Medicine, Inc.: Form 10-Q for the period ended Sep 30, 2025

Set forth below is information regarding shares of equity securities sold, and options granted, by us during the three months ended September 30, 2025 that were not registered under the Securities Act.

Recent Sales of Unregistered Equity Securities

None.

Issuer Purchases of Equity Securities

None.

Interest Rate Risk

We are exposed to market risk related to changes in interest rates of our investment portfolio of cash equivalents and investments. As of September 30, 2025, we held cash, cash equivalents, investments, and restricted cash of $227.0 million, which consisted of cash, money market funds, equity securities, and debt securities. Our primary exposure to market risk is interest income sensitivity, which is affected by changes in the general level of U.S. interest rates. The fair value of our cash equivalents, consisted of our money market funds, and investments are subject to change as a result of potential changes in market interest rates. Due to the short-term maturities of our cash equivalents and investments and the low risk profile of our investments, an immediate 10 percent change in interest rates would not have a material effect on the fair market value of our cash equivalents or investments.

Effects of Inflation

Inflation generally affects us by increasing our cost of labor and research and development costs. Although we do not believe that inflation has had a material impact on our financial position or results of operations to date, we may experience some effect in the near future (especially if inflation rates continue to rise) due to an impact on the costs to conduct research and development, labor costs we incur to attract and retain qualified personnel, and other operational costs. Inflationary costs could adversely affect our business, financial condition and results of operations.

We have established disclosure controls and procedures (as defined in Rules 13a-15(e) and 15d-15(e) under the Securities Exchange Act of 1934, as amended (the “Exchange Act”)), designed to ensure that information required to be disclosed in the reports that we file or submit under the Exchange Act is recorded, processed, summarized and reported within the time periods specified in the SEC’s rules and forms and is accumulated and communicated to management, including our Chief Executive Officer (who serves as both our principal executive officer and principal financial officer), to allow timely decisions regarding required disclosure. In addition, the design of disclosure controls and procedures must reflect the fact that there are resource constraints and that management is required to apply judgment in evaluating the benefits of possible controls and procedures relative to their costs.

Internal Control over Financial Reporting

Disclosure Controls and Procedures

Our management, with the participation of our Chief Executive Officer (who serves as both our principal executive officer and principal financial officer), evaluated, as of the end of the period covered by this Quarterly Report on

Form 10-Q, the effectiveness of our disclosure controls and procedures (as defined in Rules 13a-15(e) and 15d-15(e) under the Exchange Act). Based on that evaluation, our Chief Executive Officer concluded that our disclosure controls and procedures were effective as of September 30, 2025. Management recognizes that any controls and procedures, no matter how well designed and operated, can provide only reasonable assurance of achieving the desired control objectives and management necessarily applies its judgment in evaluating the cost-benefit relationship of possible controls and procedures. Our disclosure controls and procedures have been designed to provide reasonable assurance of achieving their objectives.

Changes in Internal Control Over Financial Reporting

There were no changes in our internal control over financial reporting that occurred during the three months ended September 30, 2025 that have materially affected, or are reasonably likely to materially affect, our internal control over financial reporting.

Investing in our common stock involves a high degree of risk. For a detailed discussion of the risks and uncertainties related to our business, please refer to the section titled “Risk Factors” in our Annual Report on Form 10-K for the year ended December 31, 2024. There have been no material changes from the risk factors set forth in our Annual Report on Form 10-K for the year ended December 31, 2024, except as set forth below.

Disruptions at the FDA, the SEC and other U.S. government agencies caused by funding shortages or global health concerns could hinder their ability to hire, retain or deploy key leadership and other personnel, or otherwise prevent new or modified products from being developed, approved, or commercialized in a timely manner or at all, or otherwise prevent those agencies from performing normal business functions on which the operation of our business may rely, which could negatively impact our business.

Currently, federal agencies in the U.S. are operating under a federal government shutdown due to expiration of the continuing resolution on September 30, 2025 and the current U.S. administration is focused on reducing costs of the federal government generally, including significantly reducing the number of government employees. The duration of the current government shutdown is unknown. Without appropriation of additional funding to federal agencies, our business operations related to our product development activities for the U.S. market could be impacted. Inadequate funding for the FDA, the SEC, the U.S. Patent and Trademark Office (the “USPTO”) and other government agencies, including from government shutdowns, or other disruptions to these agencies’ operations, could hinder their ability to hire and retain key leadership and other personnel, prevent new products and services from being developed or commercialized in a timely manner or otherwise prevent those agencies from performing normal business functions on which the operation of our business may rely, which could negatively impact our business.

The ability of the FDA to review and approve new products can be affected by a variety of factors, including government budget and funding levels, availability of personnel and other resources, statutory, regulatory, and policy changes, the FDA’s ability to hire and retain key personnel and accept the payment of user fees, and other events that may otherwise affect the FDA’s ability to perform routine functions. Average review times at the agency have fluctuated in recent years as a result. In addition, government funding of other government agencies that fund research and development activities is subject to the political process, which is inherently fluid and unpredictable. Disruptions at the FDA, USPTO and other agencies may also slow the time necessary for biologics or modifications to approved biologics to be reviewed and/or approved by necessary government agencies, which would adversely affect our business. For example, over the last several years, the U.S. government has shutdown several times and certain regulatory agencies, such as the FDA and the SEC, have had to furlough critical employees and stop critical activities. Specifically, on October 1, 2025, the U.S. federal government entered a shutdown suspending services deemed non-essential as a result of the failure by Congress to enact regular appropriations for the 2026 fiscal year. If the shutdown continues for a prolonged period of time or a widespread freeze on federal funding continues, it could result in significant delays in the of FDA's ability to timely review and process any submissions we have filed or may file or cause other regulatory delays, which could have a material adverse effect on our business. Further, in our operations as a public company, current and future government shutdowns and/or substantial leadership, personnel, and policy changes at the SEC could impact our ability to access the public markets and obtain necessary capital in order to properly capitalize and continue our operations.

Unfavorable macroeconomic conditions or market volatility resulting from geopolitical developments or national or global economic conditions, including those affecting the financial services industry, could adversely affect our business, financial condition or results of operations.

Adverse macroeconomic conditions or market volatility resulting from national or global economic developments, political unrest, high inflation, rising interest rates, international tariffs, changes in international trade relationships and military conflicts, such as the ongoing conflict between Russia and Ukraine, changes in or the disruptions of U.S. governmental agencies, whether from a continued U.S. federal government shutdown or reduced resources, disruptions in capital markets, the potential for significant changes in U.S. policies or regulatory environment, or other factors, could materially and adversely affect our business operations. Sanctions imposed by the U.S. and other countries in response to such conflicts may also continue to adversely impact the financial markets and the global economy, and any economic countermeasures by the affected countries or others could exacerbate market and economic instability. For example on September 25, 2025, the current U.S. administration announced a 100% tariff on brand-name or patented drugs unless pharmaceutical companies expand their manufacturing operations in the U.S., and may impose more restrictions on goods. While pharmaceutical products are currently excluded from the baseline and "reciprocal" tariffs imposed by the U.S., such tariffs still apply to the raw materials and other products necessary for the manufacture and formulation of our product candidates. Tariffs levied by the U.S. and other countries also may adversely affect financial markets and the global economy. There can be no assurance that further deterioration in credit and financial markets and confidence in economic conditions will not occur. For instance, actual events involving limited liquidity, defaults, non-performance or other adverse developments that affect financial institutions, transactional counterparties or other companies in the financial services industry or the financial services industry generally, or concerns or rumors about any events of these kinds or other similar risks, have in the past and may in the future lead to market-wide liquidity problems. Investor concerns regarding the U.S. or international financial systems could result in less favorable commercial financing terms, including higher interest rates or costs and tighter financial and operating covenants, or systemic limitations on access to credit and liquidity sources, thereby making it more difficult for us to acquire financing on acceptable terms or at all. In addition, any further deterioration in the macroeconomic economy or financial services industry could lead to losses or defaults by our suppliers, which in turn, could have a material adverse effect on our current and/or planned business operations and our current or projected results of operations and financial condition. For example, there has been proposed U.S. legislation, known as the BIOSECURE Act, that may restrict the ability of U.S. biopharmaceutical companies to purchase services or products from, or otherwise collaborate with, certain Chinese biotechnology companies of concern without losing the ability to contract with, or otherwise receive funding from, the U.S. government. Although the BIOSECURE Act was not passed, in October 2025, versions of the National Defense Authorization Act of 2026 passed each respective chamber of Congress and both included an amendment that will effectively implement federal government contracting, loan, and grant restrictions similar to the 2024 BIOSECURE Act. This 2025 version of the BIOSECURE Act does not identify any specific companies by name in the legislative text. If the BIOSECURE Act or similar legislation is passed in the future, we may not be able to engage a backup or alternative supplier or service provider in a timely manner or at all. This, in turn, could materially and adversely affect our or our collaborators’ ability to manufacture or supply product candidates or advance our clinical development programs, which could materially and adversely affect our business and future prospects. We continue to assess the legislation as it develops to determine whether it could have an effect on our contractual relationships. Also, current inflationary trends in the global economy may impact salaries and wages, costs of goods and transportation expenses, among other things, and recent and potential future disruptions in access to bank deposits or lending commitments due to bank failures may create market and economic instability.

A severe or prolonged economic downturn or additional global financial crises could result in a variety of risks to our business, including weakened demand for any product candidates we develop or our ability to raise additional capital when needed on acceptable terms, if at all. Weak economic conditions or significant uncertainty regarding the stability of financial markets related to stock market volatility, inflation, recession, changes in tariffs or other trade restrictions, trade agreements, trade wars or governmental fiscal, monetary and tax policies, among others, could adversely impact our business, financial condition and operating results.

Further, U.S. government appropriations have been affected by larger U.S. government budgetary issues and related legislation. In addition, in the past, U.S. debt ceiling and budget deficit concerns have increased the possibility of additional credit-rating downgrades and economic slowdowns, or a recession in the U.S. Although U.S. lawmakers passed legislation to raise the federal debt ceiling on multiple occasions, ratings agencies have lowered or threatened to lower the long-term sovereign credit rating on the U.S. The impact of this or any further downgrades to the U.S. government’s sovereign credit rating or its perceived creditworthiness could adversely affect the U.S. and global financial markets and economic conditions. As a result, government spending levels are difficult to predict beyond the near term due to numerous factors, including the external threat environment, future government priorities and the state of government finances. Significant changes in government spending or changes in U.S. government priorities, policies and requirements could have a material adverse effect on our results of operations, financial condition or liquidity.

Any of the foregoing could harm our business and we cannot anticipate all of the ways in which the current economic climate and financial market conditions could adversely impact our business.