PRME 10-K & 10-Q changes, risk factors and insider trading

Since inception, we have incurred significant operating losses. Our net loss was $195.9$201.1 million and $198.1$195.9 million for the years ended December 31, 2024,2025, and 2023,2024, respectively. As of December 31, 2024,2025, we had an accumulated deficit of $687.2$888.4 million. To date, we have financed our operations primarily through proceeds from sales of preferred stock and from our public offerings, including our initial public offering, or IPO, follow-on public offering, and privatethrough placementspayments offrom our preferredcollaboration stock.partners. Substantially all of our losses have resulted from expenses incurred in connection with our research and development and from general and administrative costs associated with our operations. We expect to continue to incur significant expenses and increasing operating losses for the foreseeable future. The net losses we incur may fluctuate significantly from year to year such that a period-to-period comparison of our results of operations may not be a good indication of our future performance. We anticipate that our expenses will increase substantially if and as we:

•hire additional research and development personnel beyondto support our currentstrategic projectionspriorities;

We have transitioned from research and development to clinical development for our lead product candidate. Because of the numerous risks and uncertainties associated with developing Prime Editing product candidates, we are unable to predict the extent of any future losses or when we will become profitable, if at all. If we do achieve profitability, we may not be able to sustain or increase profitability on a quarterly or annual basis. Our failure to become and remain profitable would decrease the value of our company and could impair our ability to raise capital, maintain our research and development efforts, expand our business or continue our operations. A decline in the value of our company could also cause you to lose all or part of your investment.

We expect our expenses to continue to increase in connection with our ongoing activities, particularly as we identify, continue the research and development of, initiate preclinical studies and clinical trials of, and seek marketing approval for, product candidates. Because we have limited financial and managerial resources, we have prioritized our research programs and lead optimization efforts in specific indications among many potential options. Specifically, our current areas of focus are hematology, immunology and oncology, liver, and lung indications. As a result of this prioritization, we may forego or delay pursuit of opportunities with other product candidates or for other indications that later prove to have greater clinical or commercial potential and we may need to reprioritize our focus in the future. For example, in September 2024 and May 2025, we strategically focused our portfolio to a set of high value programs in our current areas of focus referenced above, and are identifying partnership opportunities to advance our other programs, including those for neurological diseases, cell therapy, ocular diseases and hearing loss.loss, in partnership or through internal efforts in the future. Our resource allocation decisions may cause us to fail to capitalize on viable commercial products or profitable market opportunities. Our spending on current and future research and development programs and product candidates for specific indications may not yield any commercially viable therapies.

As of December 31, 2024,2025, our cash, cash equivalents, and investments were $190.4$177.7 million, excluding restricted cash, or $204.5$191.4 million, including restricted cash. Based on our current operating plan, we believe that our existing cash and cash equivalents and short-term investments will be sufficient to fund our operating expenses and capital expenditure requirements into the first half of 2026.2027. However, our operating plan may change as a result of factors currently unknown to us, and we may need to seek funding sooner than planned. Our future capital requirements will depend on many factors, including those discussed in the risk factor entitled “We have incurred significant losses since inception. We expect to incur losses for the foreseeable future and may never achieve or maintain profitability.”

Until such time, if ever, as we can generate substantial product revenues, we expect to finance our cash needs through a combination of public and private equity offerings, debt financings, collaborations, strategic partnerships and alliances and licensing arrangements. We do not have any committed external source of funds. To the extent that we raise additional capital through the sale of equity or convertible debt securities, your ownership interest will be diluted and the terms of these securities may include liquidation or other preferences that adversely affect your rights as a common stockholder. Debt financing, if available, may involve agreements that include covenants limiting or restricting our ability to take specific actions, such as incurring additional debt, making capital expenditures, declaring dividends and possibly other restrictions. In addition, if we raise funds through additional license and collaboration agreements, strategic alliances or licensing arrangements with third parties, we may have to relinquish valuable rights to our intellectual property, technologies, future revenue streams, research programs or product candidates we may develop, or we may have to grant licenses on terms that may not be favorable to us.

We are an early-stage company. We were founded in September 2019 and commenced operations in July 2020. Our operations to date have been limited to organizing and staffing our company, business planning, raising capital, acquiring and developing our platform and technology, identifying and advancing preclinical testing of current and future product candidates, and running our ongoing Phase 1/2 clinical trial.trial of PM359. All of our current programs are in the research, preclinical stage,research or clinicalpreclinical stage of development and their risk of failure is high. We have not yet demonstrated an ability to successfully complete any clinical trials, including large-scale, pivotal clinical trials, obtain marketing approvals, manufacture a commercial-scale therapy, arrange for a third party to do so on our behalf or conduct sales and marketing activities necessary for successful commercialization. Typically, it takes about 10 to 15 years to develop a new therapy from the time it is discovered to when it is available for treating patients.

Adverse macroeconomic conditions or market volatility resulting from national or global economic developments, political unrest, high inflation, risingchanging 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 prolonged 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. TariffsFor leviedexample, byon September 25, 2025, the current U.S. andadministration otherannounced countriesa also100% maytariff adverselyon 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-performancebrand-name or otherpatented adversedrugs developmentsunless that affect financial institutions, transactional counterparties or otherpharmaceutical companies expand their manufacturing operations 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 pastU.S., and may inimpose more restrictions on goods. Although the futurepharmaceutical leadtariff tois 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 limitationscurrently on accesshold, 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,this could have a material adverse effect on our currentsupply chain and/or planned business operationsprospects andas ourwell currentas the larger biopharmaceutical industry. While certain tariffs have subsequently been suspended, modified or projectedtemporarily reduced, we cannot predict the results of operations and financial condition. For example, there has been proposed U.S. legislation 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.government’s Wetrade continuenegotiations or the outcome of ongoing legal challenges to assessspecific thetariff 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.policies.

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,governmentresult, 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.

The success of our business depends primarily upon our ability to identify, develop and commercialize product candidates. We are early in our development efforts and haveare notfocused yeton completedidentifying and advancing our current targeted disease indications to IND-enabling studies and towards initiating clinical trials. We are also continuing to engage in regulatory interactions with the FDA based on the current data set from our Phase 1/2 clinical trial for our lead product candidate, PM359,PM359 for the treatment of CGD. Our other product candidates are in earlier stages of development. Although we believe we can demonstrate many of the key advantages of Prime Editing, because we are early in our development efforts, we are not yet certain of the results we may achieve, which may be important for registration and commercialization of our products. Such uncertainties include but are not limited to the actual size of the set of pathogenic mutations we can address, the level of editing efficiency we can produce, the degree of unwanted byproducts we may encounter, and our ability to achieve editing success in a single administration or the permanence of our edits. We have also not yet shown that preclinical editing efficacy can result in clinically important effects, nor that results of biomarker studies in our preclinical models can translate into positive results in clinical trials. One particular form of Prime Editing that uses recombinases to insert targeted “gene-sized” DNA into the genome, is in an earlier stage of research and development than our CGDCGD, AATD, and Wilson’sWilson Disease programs. We believe this promising form of Prime Editing needs more than one source of DNA as a template and may deliver with less efficacy.

All of our current product development programs are still in the research or preclinical stage of development, except fordevelopment. PM359, for which we commenced a Phase 1/2 clinical trial in 2024, was deprioritized in May 2025, though we continue to engage in regulatory interactions with the FDA based on the current data set from the clinical trial. Our research methodology may be unsuccessful in identifying other product candidates, our product candidates may be shown to have harmful side effects in preclinical in vitro experiments or animal model studies, they may not show promising signals of therapeutic effect in such experiments or studies or they may have other characteristics that may make the product candidates impractical to manufacture, unmarketable, or unlikely to receive marketing approval. We may experience delays in conducting or completing preclinical studies due to supply chain interruptions that could lead to shortages in materials or animals required for such studies. For example, it has been reported that there is a shortage of non-human primates for biomedical research, which are used in preclinical studies. We have not achieved preclinical proof of concept for many of our programs. Our proposed in-vivo delivery methods with current or future product candidates have never been evaluated in human clinical trials. Moreover, we are not aware of any clinical trials involving Prime Editing technology. Our ability to generate product revenue, which we do not expect will occur for many years, if ever, will depend heavily on the successful development and eventual commercialization of any product candidates we may develop, which may never occur. We currently generate no revenue from sales of any product, and we may never be able to develop or commercialize a marketable product.

To date, we have focused our efforts on our Prime Editing platform. However, there are numerous other companies advancing gene editing and gene therapy product candidates that are in preclinical or clinical development. Some of these other companies have previously undertaken research and development of gene editing technologies using clustered regularly interspaced short palindromic repeats, or CRISPR, or other forms such as base editing, zinc finger nucleases, or ZFNs, engineered meganucleases and transcription activator-like effector nucleases, or TALENs, but to date none has obtained marketing approval for a product candidate. There can be no certainty that Prime Editing technology will lead to the development of gene editing therapies or that other gene editing technologies will not be considered better or more attractive for the development of therapies. For example, transposons, or “jumping genes,” can insert themselves into different places in the genome and carry specific DNA sequences to specific sites without the need for making double-stranded breaks in DNA, although such methods currently cannot target specific locations. Multiple companies are also developing alternative gene editing technologies, including Tessera Therapeutics, which states it is pioneering Gene Writing™, a new genome engineering technology that writes therapeutic messages into the genome to treat diseases at their source; Metagenomi, which states it is using metagenomics – the study of genetic material recovered from organisms found in the world’s natural microbial environments) – and machine learning to discover novel genome editing systems for therapeutics development; Arbor Biotechnologies, which states it is developing genetic medicines through the discovery of programmable DNA editors to enable curative outcomes for patients; and nChroma Bio, Inc. and Moonwalk Biosciences, both of which are focused on epigenetic editing to treat disease. In addition, Beam Therapeutics is developing novel base editing technology. We have entered into a collaboration and license agreement with Beam Therapeutics,Beam, under which we grant Beam Therapeutics certain exclusive and non-exclusive rights in our Prime Editing technology in certain fields. Our license grant to Beam Therapeutics does not cover all fields and applications of Prime Editing and we retain the majority of rights to use the licensed Prime Editing technology outside of the fields licensed to Beam Therapeutics.Beam. It is possible that base editing or other gene editing technology developed by Beam Therapeutics will be competitive with our business, and it is also possible that such editing technology may be considered more attractive than Prime Editing. Therefore, Beam Therapeutics may develop competing products using such technology. For more information regarding our agreement with Beam Therapeutics,Beam, see “Business—Our License and Collaboration Agreements—Strategic relationship with Beam Therapeutics.Beam.”

WeAny havefavorable onlyresults recently initiatedfrom our firstclinical trials, including the results from our Phase 1/2 clinical trial andof any favorable results we may havePM359, may not be predictive of results that may be observed in later clinical trials or, in the case of our preclinical product candidates, in later preclinical studies. If our current or potential product candidates, our Prime Editing technology or the delivery modes we rely on to administer them lack efficacy or cause serious adverse events, undesirable side effects or unexpected characteristics, such results could delay or prevent regulatory approval of the product candidates, limit the commercial potential or result in significant negative consequences following any potential marketing approval.

We have only recently initiated our first clinical trial and anyAny favorable results we may have from our clinical trials, including the results from our Phase 1/2 clinical trial of PM359, may not be predictive of results that may be observed in later clinical trials, or in the case of our preclinical product candidates, in later preclinical studies. Furthermore, we have not generated any clinical trial results to date. Moreover, preclinical and clinical data are often susceptible to varying interpretations and analyses, and many companies that have believed their product candidates performed satisfactorily in preclinical studies and clinical trials have nonetheless failed to obtain marketing approval of their product candidates. Many product candidates that initially showed promise in early stage testing for treating a variety of diseases have later been found to lack efficacy or to cause side effects that prevented further clinical development of the product candidates.

Moreover, there have been only a very limited number of clinical trials involving the use of any gene editing technologies andand, aside from our Phase 1/2 trial of PM359, none involving gene editing technology similar to our Prime Editing technology. It is impossible to predict when or if any product candidates we may develop will prove safe in humans. In the gene therapy field, there have been several significant adverse events from gene therapy treatments in the past, including both the impact of the technology for editing, as well as the delivery methods used to convey the gene editing technology. These include a variety of safety concerns, including reported cases of leukemia, other cancers, significant morbidities and death. There can be no assurance that gene editing technologies such as our Prime Editing technology or the delivery methods we plan to use will not cause such undesirable side effects.

Additionally, a significant risk in any gene editing product candidate is that “off-target” edits, or edits far from the intended site of gene editing, or unintended consequences of on- and off-target editing may occur, which could cause serious adverse events, undesirable side effects or unexpected characteristics. One major causative factor leading to “off target” edits is the formation of double-strand breaks during gene editing. If double-strand breaks were to occur, they can also lead to decreased cell viability in edited cells, and an increase in large deletions or structural rearrangements of DNA, chromosomal translocations or joining of one chromosome to another. In certain uses of Prime Editing, such as the use of dual flaps methods, or in some cases of use of nick-guide RNAs, more than one edit occurs along the target site, and it is possible that the use of these variations of Prime Editing could result in adverse effects similar to those observed with double-strand breaks. It is possible that we will detect such off-target edits or other unintended consequences of on- or off-target edits in our current or future product candidates. Our clinical and preclinical information for our current or future product candidates is limited, and we cannot be certain that Prime Editing with any product candidates we may develop will not cause rare double-strand breaks or that off-target editing or other unintended consequences of on- or off-target editing will not occur and cause serious adverse events in any of our future clinical trials. Furthermore, the lack of observed serious side effects in our Phase 1/2 clinical trial or any preclinical studies to date does not guarantee that such side effects will not occur in later human clinical trials of any product candidates we may develop, which would adversely impact our product development programs and business.

Within our hematology, immunology and oncology area of focus, we are developing next generation CAR T-cell product(s) for autoimmune or oncology indication(s). While we believe our potential CAR T-cell product is differentiated from current products, our approach uses PASSIGE technology, which requires the use of a recombinase enzyme and Prime Editing. The use of recombinase enzymes in a human therapeutic is new, and has the potential to result in off-target insertions in the genome. TheIn 2024, the FDA has recently placed black box warnings on all CAR T-cell products based on their oncological risks, including secondary T-cell malignancies, caused by integrating vectors such as lentiviral or retroviral vectors. We cannot be sure that our approach will not result in adverse events or be subject to future black box warnings. Although we and others have demonstrated the ability to engineer gene editors which are designed to improve the specificity of their edits in a laboratory setting, we cannot be sure that our engineering efforts will be effective in any product candidates that we may develop. For example, we might not be able to engineer an editor to make the desired change, could diminish the effectiveness of an edit that we make or lead to adverse effects. Some Prime Editing approaches, such as those that use mismatch repair, or MMR, inhibition, may potentially also lead to adverse effects.

In certain of our programs, such as in our liver area of focus, we plan to use lipid nanoparticles, or LNPs, to deliver our Prime Editors. While LNPs have been used to deliver smaller molecules, such as RNAi, there is limited clinical evidence of their ability to deliver large RNA molecules, such as the ones we intend to use for our Prime Editors. LNPs have been reported to result in liver toxicity in clinical trials, and in preclinical studies LNPs have been shown to induce oxidative stress in the liver at certain doses. While we aim to continue to optimize our LNPs, there can be no assurance that our LNPs will not have undesired effects. Our LNPs could contribute, in whole or in part, to one or more of the following: immune reactions, infusion reactions, complement reactions, opsonization reactions, antibody reactions including IgA, IgM, IgE or IgG or some combination thereof, or reactions to the PEG from some lipids or PEG otherwise associated with the LNP. Certain aspects of our investigational therapies may induce immune reactions from either the mRNA or the lipid as well as adverse reactions within liver pathways or degradation of the mRNA or the LNP, any of which could lead to significant adverse events in one or more of our future clinical trials. Many of these types of side effects have been seen for legacy LNPs. There may be uncertainty as to the underlying cause of any such adverse event, which would make it difficult to accurately predict side effects in future clinical trials and would result in significant delays in our programs.

We may use AAVs, which is a relatively new approach for disease treatment. AAV vectors have known side effects and additional risks could develop in the future. In past clinical trials that were conducted by others with AAV vectors, several significant side effects were caused by gene therapy treatments, including, among others, reported cases of neurotoxicity, hepatotoxicity and death. Other potential side effects could include immunologic reactions and insertional oncogenesis, which is the process whereby the insertion of a functional gene near a gene that is important in cell growth or division results in uncontrolled cell division, which could potentially enhance the risk of malignant transformation. AAV vectors may also persist in the cell for long periods, potentially permanently, and may result in long-term adverse effects. If the AAV vectors we use demonstrate similar side effects or other adverse events, we may be unable to get IND/CTA clearance to begin clinical development or may be required to halt or delay further clinical development of any of our current or future product candidates. Furthermore, the FDA has stated that non-AAV vectors possess characteristics that may pose high risks of delayed adverse events.

There are several companies utilizing Cas9 nuclease technology, including Caribou Biosciences, Inc., Editas Medicine, Inc., CRISPR Therapeutics AG, Intellia Therapeutics, Inc. and Kamau Therapeutics, Inc., among others. Several additional companies such as Sangamo Therapeutics, Inc., Precision BioSciences, Inc. and bluebirdGenetix bio,Biotherapeutics, Inc. utilize alternative nuclease-based genome editing technologies, including ZFNs, engineered meganucleases and TALENs. Beam Therapeuticsis andone Verve Therapeutics, Inc. are amongof a number of companies that utilize base editing technology. In addition, other private companies such as Tessera Therapeutics, Inc. have announced their work in recombinase DNA and RNA gene writers. Other companies have announced intentions to enter the gene editing field, such as Moderna, Inc. and Pfizer Inc. Most recently, new epigenetic editing companies have emerged, such as Moonwalk Biosciences, Inc., nChroma Bio, Inc. and Tune Therapeutics, Inc. In addition, we face competition from companies utilizing gene therapy, oligonucleotides and cell therapy therapeutic approaches. Several companies such as Arbor Biotechnologies, Inc., Scribe Therapeutics Inc., Mammoth Biosciences, Inc. and Metagenomi, Inc. are actively searching for novel genome editing components, have reported the discovery of new DNA-cutting enzymes, and have announced gene editing programs. Other companies are active in LNP delivery technologies and advancing those into therapeutics using genetic therapies, including Recode Therapeutics, Inc., Verve Therapeutics, Inc., recently acquired by Eli Lilly and Company, Generation Bio Co. and Beam Therapeutics,Beam, among others.

Any product candidates we may develop will likely require processing steps that are more complex than those required for most chemical pharmaceuticals. For example, we currently obtain pegRNA from partners and vendors. Future needs could require additional pegRNA lengths or increased purity, potentially beyond what our partners and vendors can currently supply. Moreover, unlike chemical pharmaceuticals, the physical and chemical properties of a biologic such as the product candidates we intend to develop generally cannot be fully characterized. As a result, assays of the finished product candidate may not be sufficient to ensure that the product candidate will perform in the intended manner. Problems with the manufacturing process, even minor deviations from the normal process, could result in product defects or manufacturing failures that result in lot failures, product recalls, product liability claims, insufficient inventory or potentially delay progression of our potential IND filings. If we successfully develop product candidates, we may encounter problems achieving adequate quantities and quality of clinical-grade materials that meet the FDA, the EMA or other comparable applicable foreign standards or specifications with consistent and acceptable production yields and costs. For example, the current approach of manufacturing AAV vectors may fall short of supplying required number of doses needed for advanced stages of preclinical studies or clinical trials, and the FDA may ask us to demonstrate that we have the appropriate manufacturing processes in place to support the higher-dose group in our preclinical studies or clinical trials. In addition, any product candidates we may develop will require complicated delivery methods, such as electroporation, LNPs or viral vectors, each of which will introduce additional complexities in the manufacturing process. We may also have similar issues to other companies that have had difficulties in receiving FDA, or other regulatory agency approval for key potency assays needed for regulatory approval and/or drug release from the manufacturer.

If conflicts arise between us and our collaborators or strategic partners, these parties may act in a manner adverse to us and could limit our ability to implement our strategies.strategies or we could lose license rights that are important to our business.

Our collaborators or strategic partners could also develop competing products, preclude us from entering into collaborations with their competitors, fail to obtain timely regulatory approvals, prevent us from obtaining timely regulatory approvals, terminate their agreements with us prematurely or fail to devote sufficient resources to the collaboration efforts, including development, delivery, manufacturing and commercialization of products. Any of these developments could harm our company and product development efforts.

Although we designed the clinical trial for our current product candidate, PM359,PM359 and intend to design the clinical trials for future product candidates, a CRO is conductingconducted our clinical trial for PM359, and CROs will conduct some or all of our future clinical trials. As a result, many important aspects of our development programs, including their conduct and timing, will be outside of our direct control. Our reliance on third parties to conduct preclinical studies and current and future clinical trials will also result in less direct control over the management of data developed through preclinical studies and clinical trials than would be the case if we were relying entirely upon our own staff. Communicating with outside parties can also be challenging, potentially leading to mistakes as well as difficulties in coordinating activities. Among other reasons that may delay or impact the development of our current and future product candidates, outside parties may:

We also relyrelied on third parties to store and distribute drug supplies for our currentpast clinical trial and expect to rely on third parties to do the same for future clinical trials. Any performance failure on the part of our distributors could delay clinical development or marketing approval of any product candidates we may develop or commercialization of our therapies, producing additional losses and depriving us of potential product revenue.

We contract with third parties for the manufacture of materials for our research programs and current clinical trial,programs, and expect to continue to do so for future clinical trials and for any commercialization of product candidates that we may develop. This reliance on third parties increases the risk that we will not have sufficient quantities of such materials, product candidates or any therapies that we may develop and commercialize, or that such supply will not be available to us on time or at an acceptable cost.

We do not have anylimited internal manufacturing facilitiescapabilities at the present time. We currently rely on third-party manufacturers to manufacture many of our materials for research, preclinical studies and clinical trials, and expect to continue to do so. We have not yet formulated our plans for commercial supply of any product candidates that we may develop or for which we or our collaborators may in the future obtain marketing approval, but our future decisions may be subject to similar risks to the ones discussed below.

Any performance failure on the part of our existing or future manufacturers could delay clinical development or marketing approval. We do not currently have arrangements in place for redundant supply for bulk drug substances. If any third party-manufacturer with whom we contract fails to perform its obligations, we may be forced to manufacture the materials ourselves, for which we may not have the facilities or resources, or enter into an agreement with a different third party-manufacturer, which we may not be able to do on reasonable terms, if at all. In either scenario, our clinical trials supply could be delayed significantly as we establish alternative supply sources. In some cases, the technical skills required to manufacture our products or product candidates may be unique or proprietary to the original third party-manufacturer and we may have difficulty, or there may be contractual restrictions prohibiting us from, transferring such skills to a back-up or alternate supplier, or we may be unable to transfer such skills at all. In addition, if we are required to change third party-manufacturers for any reason, we will be required to verify that the new third party-manufacturer maintains facilities and procedures that comply with quality standards and with all applicable regulations. We will also need to verify, such as through a manufacturing comparability study, that any new manufacturing process will produce our current and future product candidates according to the specifications previously submitted to the FDA or another regulatory authority. The delays associated with the verification of a new third party-manufacturer could negatively affect our ability to develop product candidates or commercialize our products in a timely manner or within budget. Furthermore, a third party-manufacturer may possess technology related to the manufacture of our product candidate that such third party-manufacturer owns independently. This would increase our reliance on such third party-manufacturer or require us to obtain a license from such third party-manufacturer in order to have another third party-manufacturer manufacture our product candidates, which may not be available on commercially reasonable terms, or at all. In addition, changes in manufacturers often involve changes in manufacturing procedures and processes, which could require that we conduct bridging studies between our prior clinical supply used in our clinical trials and that of any new manufacturer. We may be unsuccessful in demonstrating the comparability of clinical supplies which could require the conduct of additional clinical trials.

In addition, regional or single-source dependencies may in some cases accentuate these risks. For example, the pharmaceutical industry generally, and in some instances we or our collaborators or other third parties on which we rely, depend on China-based suppliers or service providers for certain raw materials, goods, including biologically derived substances, products and services, or other activities. Our ability or the ability of our collaborators or such other third parties to continue to engage these China-based suppliers or service provides and Chinese biotech companies for certain preclinical research programs and clinical development programs could be restricted due to geopolitical developments between the United States and China, including as a result of the escalation of tariffs ortariffs, other trade restrictions or if the previouslyenactment proposed federal legislation known asof the BIOSECURE Act or similar legislation. While the BIOSECURE Act is primarily directed at U.S. government procurement and funding and has not yet been fully implemented through final regulations, there remains a similarcontinued lawpolicy interest in limiting U.S. companies’ relationships with biotechnology providers with relationships with foreign adversaries. For instance, if our, our collaborators’, or other third parties’ China-based suppliers or service providers were named as a “biotechnology company of concern,” such designation could have the downstream effect of restricting our ability to beenter enacted.into contracts with or receive funding from U.S. federal agencies from purchasing services or equipment involving the use of those Chinese biotechnology companies, as well as supply chain disruptions or delays. 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 do not currently own any issued patents and are heavily reliant upon certain patent rights and proprietary technology we have licensed from third parties that are important or necessary to the development of our Prime Editing technology and product candidates. For example, we are a party to two license agreements with Broad Institute. In September 2019, we entered into a license agreement with Broad Institute, or the Broad License Agreement, and in May 2020, February 2021, December 2022, September 2024, and September 2024,2025, we entered into amendments to such license agreement. In December 2022, we entered into a new license agreement with Broad Institute, or the 2022 Broad License Agreement. Under the amended Broad License Agreement and the 2022 Broad License Agreement, Broad Institute grants us certain rights and licenses under certain patent rights it owns or controls relating to our Prime Editing technology and product candidates. Each license agreement imposes various diligence, milestone payment, royalty, insurance and other obligations on us. Our licenses are subject to Broad Institute’s inclusive innovation model, pursuant to which Broad Institute retains the right, in certain circumstances, to grant to third parties (other than specified competitors of ours) licenses under the licensed patent rights that would otherwise fall within the scope of the exclusive license granted to us. All gene targets, which are any human genes to which a program is directed, are subject to Broad Institute’s march-in license, which means Broad Institute has the right to terminate our license to gene targets under certain conditions and could make one or more gene targets unavailable to us. However, if we initiate a program for a gene target, in accordance with the terms of each license agreement, we may block a march-in request by making certain showing and by continuing to use commercially reasonable efforts to continue to progress such development. Internally, we determine when a program for a gene target has been initiated by considering factors such as whether a gene target has been identified as the subject of a program, how much time or resources have been dedicated to researching, developing, and/or designing and using reagents for a program, and the amount of preclinical testing in process for such program. If we fail to comply with these or other obligations in our current or future license agreements, our licensors may have the right to terminate our license, in which event we would not be able to develop or market our Prime Editing technology or any other technology or product candidates covered by the intellectual property licensed under this agreement. Our business would be seriously harmed if any current or future licenses terminate, if our licensors fail to abide by the terms of the license, if our licensors fail to enforce licensed patents against infringing third parties, if the licensed patents or other rights are found to be invalid or unenforceable, or if we are unable to enter into necessary licenses on acceptable terms. If our license agreements terminate, or we experience a reduction or elimination of licensed rights under these agreements, we may have to negotiate new or reinstated licenses with less favorable terms or we may not have sufficient intellectual property rights to operate our business. Moreover, if certain of our license agreements terminate, we may be required to continue to license or assign certain of our intellectual property to the applicable counterparty.

Certain of the patent rights that we license from Broad Institute under the Broad License Agreement are co-owned by Broad Institute with Harvard and certain of the licensed patent rights under the Broad License Agreement are co-owned by Broad Institute, Harvard, and Massachusetts Institute of Technology, or MIT. The patent rights that we license from Broad Institute under the 2022 Broad License Agreement are co-owned by Broad Institute with Harvard, the Trustees of Princeton University, or Princeton, and the Regents of the University of California, or University of California. In addition, some of the inventors of the licensed patent and patent applications are or were employees of HHMI, which retains certain rights to patents and patent applications invented by their employees. Our rights to our in-licensed patents and patent applications from Broad Institute are dependent, in part, on inter-institutional or other operating agreements between Broad Institute, Harvard, MIT, University of California, Princeton and HHMI. If Broad Institute, Harvard, MIT, University of California, Princeton or HHMI breaches or terminates such inter-institutional or operating agreements, our rights to such in-licensed patents and patent applications may be adversely affected. We have also licensed certain improvements to Prime Editing from Dr. Liu’s laboratory at Broad Institute. For example, Dr. Liu’s laboratory at Broad Institute developed engineered pegRNAs, or epegRNAs, which we have exclusively in-licensed. Dr. Liu has entered into an agreement with us pursuant to which he is obligated to assign to us any inventions with respect to the services he performs for us. However, such obligations are subject to limitations and do not extend to his work in other fields or to the intellectual property arising from his employment with Harvard, HHMI and Broad Institute. To obtain such intellectual property rights, we would need to enter into license agreements with such institutions, and such license agreements may not be available on commercially reasonable terms or at all.

Additionally, in September 2019, we established a strategic relationship with Beam Therapeutics,Beam, a biotechnology company developing gene editing products using its proprietary base editing technology. Under our license and collaboration agreement with Beam Therapeutics,Beam, or the Beam Collaboration Agreement, each party grants to the other certain exclusive and non-exclusive licenses and rights to certain Prime Editing, CRISPR and delivery technologies for use in certain specified fields. Activities performed by Prime and Beam Therapeutics under the Beam Collaboration Agreement may lead to co-owned patents and patent applications.

These and other licenses may not provide exclusive rights to use such intellectual property and technology in all relevant fields of use and in all territories in which we may wish to develop or commercialize our Prime Editing technology and product candidates in the future. Some licenses granted to us are expressly subject to certain preexisting rights held by the licensors or certain third parties. As a result, we may not be able to prevent third parties from developing and commercializing competitive products in certain territories or fields. For example, the rights granted to us under each license agreement are subject to certain retained rights ofof, among others, Broad Institute, MIT, Harvard, Princeton, University of California, HHMI and the U.S. federal government, and the rights granted to us under the Beam Collaboration Agreement are subject to certain third party agreements and certain rights retained by third parties. Additionally, each license agreement with Broad Institute provides that our field of use is limited to the field of prevention or treatment of human disease, and most licenses granted to us under each license agreement with Broad Institute are further limited to the prevention or treatment of human disease by editing (including modifying or converting) or targeting DNA ex vivo, in vivo, or through xeno-transplantation methods and includes other specified exclusions. If we determine that rights to additional fields, including the specifically excluded fields, are necessary to commercialize our product candidates or maintain our competitive advantage, we may need to obtain a license from Broad Institute and/or other third parties in order to continue developing, manufacturing or marketing our product candidates. We may not be able to obtain such a license on an exclusive basis, on commercially reasonable terms, or at all, which could prevent us from commercializing our product candidates or allow our competitors or other third parties the chance to access technology that is important to our business.

We do not control the preparation, filing, prosecution and maintenance of the patents and patent applications covering the technology that we license from Broad Institute or Beam Therapeutics.Beam. For example, pursuant to our licenses with Broad Institute and Beam Therapeutics,Beam, our licensors retain control of preparation, filing, prosecution and maintenance of their wholly-owned patents and patent applications. We rely on such licensors to determine inventorship and perfect priority of their patent applications. We cannot be certain that these patents and patent applications will be prepared, filed, prosecuted, maintained and defended in a manner consistent with the best interests of our business. If Broad Institute or Beam Therapeutics fails to prosecute or maintain such patents and patent applications or loses rights to such patents and patent applications, the rights we have licensed may be reduced or eliminated, our right to develop and commercialize any of our product candidates we may develop that are the subject of such licensed rights could be adversely affected and we may not be able to prevent third parties from making, using and selling competing products. In addition, we do not control all enforcement of the patents and patent applications we license from Broad Institute. It is possible that our licensors’ enforcement of patents against infringers or defense of such patents against challenges of validity or claims of enforceability may be less vigorous than if we had conducted them ourselves, or may not be conducted in accordance with our best interests.

Pursuant to our license agreements with Beam Therapeutics and Broad Institute, we are generally responsible for bringing any actions against any third party for infringing on certain of the patent rights we have licensed from such counterparty, subject to certain conditions. Certain provisions of each license agreement with Broad Institute also require us to meet development thresholds within specified timeframes to maintain the license, including establishing a set timeline for developing and commercializing products, while some provisions of the Beam Collaboration Agreement require us to use commercially reasonable efforts to conduct development activities for collaboration products. In spite of our efforts, Broad Institute, Beam Therapeutics,Beam, or any future licensor from whom we may seek to license intellectual property rights might conclude that we have materially breached our obligations under such license agreements and might therefore terminate the license agreements, thereby removing or limiting our ability to develop and commercialize products and technology covered by these license agreements. If these licenses agreements are terminated, or if the underlying patent rights fail to provide the intended exclusivity, competitors or other third parties may be able to seek regulatory approval of, and to market, products identical to ours and we may be required to cease our development and commercialization of our Prime Editing technology or product candidates. Any of the foregoing could have a material adverse effect on our competitive position, business, financial condition, results of operations and growth prospects. Disputes may arise regarding intellectual property subject to a licensing agreement, including:

In addition, the agreements under which we currently license intellectual property rights from Beam Therapeutics and Broad Institute are complex, and certain provisions in such agreements may be susceptible to multiple interpretations. The resolution of any contract interpretation disagreement that may arise under our existing license agreements or future license agreements into which we may enter could narrow what we believe to be the scope of our rights to the relevant intellectual property or technology or broaden what we believe to be the scope of the licensor’s rights to our intellectual property and technology, or increase what we believe to be our financial or other obligations under the relevant agreement, any of which could have a material adverse effect on our business, financial condition, results of operations and prospects. For example, we have exclusively licensed and sublicensed certain of our owned and licensed intellectual property rights to Beam Therapeuticspursuant underto the Beam Collaboration Agreement in certain fields. SuchThe agreementparties mayhave bepresented susceptiblediffering tocontractual multiple interpretations andinterpretations, the resolution of any contract interpretation disagreementwhich could expand the field of exclusivity or other rights that we havebelieve were granted to Beam TherapeuticsBeam, and therefore,therefore narrow what we believe to be our field of exclusivity or rights with respect to such licensed intellectual property rights. For more information, see the risk factor entitled “If conflicts arise between us and our collaborators or strategic partners, these parties may act in a manner adverse to us and could limit our ability to implement our strategies or we could lose license rights that are important to our business.” Moreover, if disputes over intellectual property that we have licensed prevent or impair our ability to maintain our current licensing arrangements on commercially acceptable terms, we may be unable to successfully develop and commercialize the affected product candidates. As a result, any termination of or disputes over our intellectual property licenses could result in the loss of our ability to develop and commercialize our Prime Editing technology or other product candidates or we could lose other significant rights, any of which could have a material adverse effect on our business, financial conditions, results of operations and prospects. It is also possible that a third party could be granted limited licenses to some of the same technology, in certain circumstances.

We have in-licensed five10 issued U.S. patents,patents sixor allowed U.S. patent applications, 20 granted ex-U.S. patents,patents or allowed ex-U.S. patent applications, and own and have in-licensed a number of patent applications that cover Prime Editing methods and its components and systems. We and our licensors have filed patent applications intended to specifically cover our Prime Editing technology and uses with respect to treatment of particular diseases and conditions. While we in-license five10 issued U.S. patents,patents or allowed U.S. patent applications, we do not currently own any, or in-license any other, issued U.S. patents.

We have five10 in-licensed issued U.S. patents or allowed U.S. patent applications and six20 granted ex-U.S. patents,patents or allowed ex-U.S. patent applications, all of which cover Prime Editing methods and its components and systems. Our owned and in-licensed patent applications contain claims directed to compositions of matter for our Prime Editing product candidates, as well as methods directed to the use of such product candidates for gene therapy treatment. Method-of-use patents do not prevent a competitor or other third party from developing or marketing an identical product for an indication that is outside the scope of the patented method. Moreover, with respect to method-of-use patents, even if competitors or other third parties do not actively promote their product for our targeted indications or uses for which we may obtain patents, providers may recommend that patients use these products off-label, or patients may do so themselves.

The strength of patents in the biotechnology and pharmaceutical field involves complex legal and scientific questions and can be uncertain. The issuance of a patent is not conclusive as to its inventorship, scope, validity, or enforceability, and our or our licensors’ current and future patents may be challenged in the courts or patent offices in the United States and abroad. The patent applications that we own or in-license may fail to result in issued patents with claims that cover our product candidates or uses thereof in the United States or in other foreign countries. For example, while our or our licensors’ patent applications are pending, such patent applications may now or in the future be subject to a third-party pre-issuance submission of prior art to the U.S. Patent and Trademark Office, or USPTO,USPTO or become involved in interference or derivation proceedings or equivalent proceedings in foreign jurisdictions. For example, prior art was submitted by one or more third parties with respect to certain of our Patent Cooperation Treaty, or PCT, patent applications as well as in patent applications filed in the European Patent Office in-licensed from Broad Institute directed to Prime Editing. Third parties may challenge the inventorship, priority of invention, validity, enforceability or scope of our in-licensed patents and our or our licensors’ patent applications that successfully issue, including through opposition, revocation, reexamination, post-grant and inter partes review proceedings and litigation. Moreover, we, or one of our licensors, may have to participate in interference proceedings declared by the USPTO to determine priority of invention or in post grant challenge proceedings, such as oppositions in a foreign patent office, that challenge priority of invention or other features of patentability. An adverse determination in any such submission, proceeding or litigation may result in loss of patent rights, loss of exclusivity, or in patent claims being narrowed, invalidated, or held unenforceable, which could limit our ability to stop others from using or commercializing similar or identical technology and products, allow third parties to commercialize our technology or product candidates and compete directly with us, without payment to us, limit the duration of the patent protection of our technology and product candidates, or result in our inability to manufacture or commercialize products without infringing third-party patent rights. Furthermore, even if they are unchallenged, our patent rights may not adequately protect our intellectual property or prevent others from designing around our platform technology or product candidates. If the breadth or strength of protection provided by our in-licensed patents or patents that may issue from the patent applications we own or in-license with respect to our Prime Editing technology and product candidates is threatened, it could dissuade companies from collaborating with us to develop, and threaten our ability to commercialize, our product candidates. Further, if we encounter delays in development, testing and regulatory review of new product candidates, the period of time during which we could market our product candidates under patent protection would be reduced.

We currently have in-licensed one20 ex-U.S. granted patents or allowed ex-U.S. patent applications that coverscover Prime Editing components and methods of use. Although we own and have in-licensed numerous ex-U.S. patent applications, we have limited intellectual property rights outside the United States. Filing, prosecuting and defending patents on our Prime Editing technologies and product candidates in all countries throughout the world would be prohibitively expensive and our intellectual property rights in some countries outside the United States can be less extensive than those in the United States. The laws of foreign countries do not protect intellectual property rights to the same extent as federal and state laws of the United States, even in jurisdictions where we or our licensors do pursue patent protection. In addition, our intellectual property license agreements may not always include worldwide rights. Consequently, we or our licensors may not be able to prevent third parties from practicing our inventions in all countries outside the United States, or from selling or importing products made using our inventions in and into the United States or other jurisdictions. Third parties may use our technologies in jurisdictions where we have not obtained patent protection to develop their own products and, further, may export otherwise infringing products to territories where we have patent protection but where enforcement is not as strong as that in the United States. These products may compete with our product candidates and patents that may issue from our or our licensors’ pending patent applications or other intellectual property rights may not be effective or sufficient to prevent them from competing.

We currently have rights to intellectual property, through licenses from third parties, to identify and develop product candidates, and we expect to seek to expand our product candidate pipeline in part by in-licensing additional rights to key technologies. The future growth of our business will depend in part on our ability to in-license or otherwise acquire the rights to additional product candidates and technologies. Although we have succeeded in licensing technologies from Beam Therapeutics and Broad Institute in the past, we cannot guarantee that we will be able to in-license or acquire additional rights to any product candidates or technologies from Beam Therapeutics,Beam, Broad Institute, or other third parties on acceptable terms or at all. For example, Broad Institute is developing improvements to the Prime Editing technology for which we may find it necessary or useful to obtain a license. In addition, our agreements with Beam Therapeutics and Broad Institute provide that our fields of use exclude particular fields. If we determine that rights to such fields are necessary to commercialize our technology or product candidates or maintain our competitive advantage, we may need to obtain a license from Beam Therapeutics or Broad Institute in order to continue developing, manufacturing or marketing our technology or product candidates. In addition, we may seek to obtain additional licenses from our licensors and, in connection with obtaining such licenses, we may agree to amend our existing licenses in a manner that may be more favorable to the licensors, including by agreeing to terms that could enable third parties (potentially including our competitors) to receive licenses to a portion of the intellectual property that is subject to our existing licenses. Additionally, upon our finalization of our product candidates, we may determine that there are third parties who possess technologies related to gene editing or other technologies which we may need to in-license, including intellectual property covering the use of Cas domains and RTs. We may not be able to obtain such a license on an exclusive basis, on commercially reasonable terms, or at all, which could prevent us from commercializing our product candidates or allow our competitors or other third parties the chance to access technology that is important to our business.

Furthermore, there has been extensive patenting activity in the field of gene editing. Pharmaceutical companies, biotechnology companies and academic institutions are competing with us or are expected to compete with us in the in the field of gene editing technology and filing patent applications potentially relevant to our business and we are aware of certain third-party patent applications that, if issued, may allow the third party to circumvent our patent rights.business. For example, we are aware of several third-party patents and patent applications that may be construed to cover or be relevant to our Prime Editing and PASSIGE technologies and product candidates. In order to market our product candidates, we may find it necessary or prudent to obtain licenses from such third-party intellectual property holders. However, we may be unable to secure such licenses or otherwise acquire or in-license any compositions, methods of use, processes, or other intellectual property rights from third parties that we identify as necessary for product candidates we may develop and our Prime Editing technology. We may also require licenses from third parties for certain additional technologies, including technologies relating to Prime Editing, such as guide RNA modification, target sequences, Cas domains such as Cas9, reverse transcriptases such as Moloney murine leukemia virus reverse transcriptase, as well as delivery technologies for product candidates we may develop. For our PASSIGE technology, we may require additional licenses from third parties for recombinase technologies.

Several patents and pending applications with claims directed to foundational aspects of CRISPR-Cas9 gene editing are currently involved in interference proceedings at the USPTO. The Patent Trial and Appeal Board, or PTAB, of the USPTO declared a second interference between 14 pending applications co-owned by the CVC and 13 patents and one pending application co-owned by Broad Institute, MIT, Rockefeller University and Harvard, which we refer to as the Boston Licensing Parties, in 2019 after the first interference between the two parties was terminated in 2018. In February 2022, the PTAB issued a decision in the second interference, granting priority to the patents and pending application co-owned by the Boston Licensing Parties over the pending applications co-owned by the CVC. In September 2022, the CVC appealed the PTAB’s decision, at the U.S. Court of Appeals for the Federal Circuit. On May 12, 2025, the Federal Circuit vacated and remanded the appealPTAB’s ispriority ongoing.determination, ruling that the PTAB applied an incorrect legal standard but declining to decide the substantive priority issue. The PTAB has not yet issued a final decision following the remand. While the second interference was in progress, Toolgen joined the patent dispute and two more interferences were declared in December 2020, between a pending application owned by Toolgen and several pending applications co-owned by the CVC or patents and pending applications co-owned by the Boston Licensing Parties. In June 2021, two additional interferences were declared between patents and applications co-owned by the Boston Licensing Parties or pending applications co-owned by the CVC and pending applications owned by Sigma-Aldrich. The PTAB subsequently suspended the interferences involving Toolgen and Sigma-Aldrich until the Federal Circuit issues a decision in the appeal between the CVC and the Boston Licensing Parties over the PTAB’s decision in the second interference. It is presently unclear who will prevail in these proceedings and own or partially own the patents subject to such interferences. If it is necessary for us to obtain a license to one or more of the patents currently involved in such interference proceedings, such patents may not be available to license on commercially reasonable terms or at all. For example, we are aware that the Boston Licensing Parties and CVC have previously licensed certain of such patents to third parties. Our ability to commercialize our product candidates in the United States and abroad may be adversely affected if we cannot obtain a license on commercially reasonable terms to relevant third-party patents that cover our product candidates or Prime Editing technology.

As is common in the biotechnology and pharmaceutical industries, we employ individuals who were previously employed at universities, research institutions, or other biotechnology and pharmaceutical companies, including our competitors or potential competitors. Although no claims against us are currently pending, and although we try to ensure that our employees, consultants, independent contractors or other third parties do not use the proprietary information or know-how of others in their work for us, we may be subject to claims that we or our employees, consultants, independent contractors or other third parties have inadvertently or otherwise used or disclosed intellectual property, including trade secrets or other proprietary information, of a former employer or other third parties. Furthermore, any disclosure, either intentional or unintentional, by our employees, consultants or vendors, or misappropriation by third parties (such as through a cybersecurity breach) of our trade secrets or proprietary information could enable competitors to duplicate or surpass our technological achievements, thus eroding our competitive position in our market. Such risk of disclosure can be increased by our use of artificial intelligence, or AI, technologies and can result in misappropriation and other security incidents and breached. Litigation may be necessary to defend against these claims. If we fail in defending any such claims, in addition to paying monetary damages, we may lose valuable intellectual property rights or personnel. Even if we are successful in defending against such claims, litigation or other legal proceedings relating to intellectual property claims may cause us to incur significant expenses and could distract our technical and management personnel from their normal responsibilities. In addition, there could be public announcements of the results of hearings, motions or other interim proceedings or developments, and if securities analysts or investors perceive these results to be negative, it could have a substantial adverse effect on the price of our common stock. This type of litigation or proceeding could substantially increase our operating losses and reduce our resources available for development activities. We may not have sufficient financial or other resources to adequately conduct such litigation or proceedings. Certain third parties, including our competitors, may be able to sustain the costs of such litigation or proceedings more effectively than we can because of their substantially greater financial resources. Uncertainties resulting from the initiation and continuation of patent litigation or other intellectual property related proceedings could adversely affect our ability to compete in the marketplace.

The FDA, the EMA and the National Institutes of Health, or NIH,NIH have demonstrated caution in their regulation of gene therapy treatments, and ethical and legal concerns about gene therapy and genetic testing may result in additional regulations or restrictions on the development and commercialization of any product candidates we may develop, which may be difficult to predict.

Regulatory requirements in the United States and in other jurisdictions governing the development of gene therapy products have changed frequently and may continue to change in the future. Recently, theThe FDA issued several newguidance documents and draft guidance documents on gene therapy products, andincluding on innovative clinical trial designs for gene therapy products in small populations. In January 2024, the FDA finalized its guidance document providing recommendations for human genome editing gene therapy products. In addition to the government regulators, the IBC and IRB of each institution at which we will conduct clinical trials of our current or future product candidates, or a central IRB if appropriate, would need to review the proposed clinical trial to assess the safety of the trial. In addition, adverse developments in clinical trials of gene therapy product candidates conducted by others may cause the FDA or other oversight bodies to change the requirements for approval of any of our potential product candidates. Similarly, the EMA governs the development of gene therapies in the European Union and may issue new guidelines concerning the development and marketing authorization for gene therapy products and require that we comply with these new guidelines. These regulatory review agencies and committees and the new requirements or guidelines they promulgate may lengthen the regulatory review process, require us to perform additional studies or trials, increase our development costs, lead to changes in regulatory positions and interpretations, delay or prevent approval and commercialization of any product candidates we may develop or lead to significant post-approval limitations or restrictions. As we advance our current and future product candidates, we will be required to consult with these regulatory agencies and committees and comply with applicable requirements and guidelines. If we fail to do so, we may be required to delay or discontinue development of such product candidates. These additional processes may result in a review and approval process that is longer than we otherwise would have expected. Delays as a result of an increased or lengthier regulatory approval process or further restrictions on the development of our current and future product candidates can be costly and could negatively impact our or our collaborators’ ability to complete clinical trials and commercialize our current and future product candidates in a timely manner, if at all.

Any product candidate for which we obtain marketing approval, along with the manufacturing processes, post-approval clinical data, labeling, sampling, advertising and promotional activities for such product, will be subject to continual requirements of and review by the FDA, the EMA and other regulatory authorities. These requirements include submissions of safety and other post-marketing information and reports, facility registration and drug listing requirements, cGMP requirements relating to quality control, quality assurance and corresponding maintenance of records and documents, applicable product tracking and tracing requirements and requirements regarding the distribution of samples to physicians and recordkeeping. In addition, our manufacturing and testing facilities will be required to undergo pre-license inspections and pre-approval inspections. Even if marketing approval of a product candidate is granted, the approval may be subject to limitations on the indicated uses for which the products may be marketed or to the conditions of approval, or contain requirements for costly post-marketing testing and surveillance to monitor the safety or efficacy of the products.

To date, we have not generated any revenue from product sales and do not expect to generate any revenue from the sale of products for the foreseeable future. Our revenues to date have been generated through research collaboration and license agreements. We recognize revenue over the expected performance period under each agreement. We expect that our revenue for the next several years will be derived primarily from our current collaboration agreements and any additional collaborations that we may enter into in the future. To date, we have not generatedreceived any revenue from product sales or royalties and do not expect to generateunder any revenue from the sale of productsour orexisting royaltiescollaboration for the foreseeable future.agreements.

Research and development expenses consist primarily of costs incurred forin ourconnection research activities, including our discovery efforts, andwith the development and research of our productimmediate candidates.target indications and our differentiation target indications. These expenses include:

•personnel-related expenses, including salaries, bonuses, benefits,benefits and stock-based compensation for employees engaged in manufacturing, and research and development functions;

We expense all research and development costs in the periods in which they are incurred. Most of our research and development expenses have been related to early stage development activities. ExternalIn the future, external research and development costs for any individual product candidate will be tracked commencing upon the FDA’s clearance of the IND application for that product candidate.candidate nomination. We do not allocate employee costs, costs associated with our discovery efforts, laboratory supplies, and facilities expenses, including depreciation or other indirect costs, to specific product development programs because these costs are deployed across multiple programs and our platform and, as such, are not separately classified.

We expect our research and development expenses tomay continue to increase substantially forin the foreseeable future with our planned research and development activities related to developing any future product candidates, including investments in manufacturing, as we advance any product candidates we may identify and begin to conduct clinical trials, and with our obligations under the BMS Collaboration Agreement.

We anticipate that our general and administrative expenses will increase in the future asif we increase our headcount to support research and development activities; increased accounting, legal, insurance, and investor and public relations costs as we continue to operate as a public company; and additional intellectual property-related expenses as we file patent applications to protect innovations arising from our research and development activities.

•interest and otheramortization incomerelated earned onto our short-term investments; and

•the change in the fair value of our short-term investment in Beam Therapeutics Inc., or Beam, a related party, in connection with the Beam Collaboration Agreement, which is discussed in greater detail in Item 1. Business, of this Annual Report on Form 10-K.

•$11.3$11.0 million increase in facility-related expense primarily due to the expansion and build out of our laboratory space.space at 60 First Street and 500 Arsenal Street and due to a higher amount of facility costs being allocated to our research and development function;

•$1.9$6.9 million increase in license feesand forIP amountscosts, primarily due to the Broadissuance resultingof fromrestricted thestock BMS Collaboration Agreement.units;

The $6.8$2.2 million increase in general and administrative expense for the year ended December 31, 20242025 as compared to the year ended December 31, 20232024 is primarily driven by a $7.0 million increase in professional and consultant fees due to an increase in corporate legal expenses. This is offset by:

•$9.5$3.5 million increasedecrease in personnel expense, due to a majority of which was an increasedecrease in non-cash stock-based compensation expense of $7.4$3.5 million; and

•$1.5$1.3 million increasedecrease in facility related and other primarily relateddue to thea ongoinghigher build outproportion of our facility atspace 60being Firstutilized Street.in research and development activities.

Accretion (amortization) of investments

Accretion (amortization) of investments for each of the periods presented is a result of increase (decrease) in the pricevalue atof whichthe our investmentsmarketable are purchased. If the investments aresecurities purchased at a pricediscount different(premium) fromto their parface value, the difference is accreted, if lower than par, or amortized, if higher than par, until the investment matures or is sold.value.

Since our inception, we have incurred significant operating losses. We expect to incur significant expenses and operating losses for the foreseeable future as we commence the clinical development of our programs and continue our platform development and early-stage research activities. We have not yet commercialized any products and we do not expect to generate revenue from sales of products for several years, if at all. To date, we have funded our operations primarily with proceeds from sales of preferred stock, public offerings of our common stock, and through payments from our collaboration partners. As of December 31, 2024,2025, we had cash and cash equivalents, short-term investments, and related party short-term investments of $190.4$177.7 million, excluding our restricted cash, or $204.5$191.4 million, including restricted cash.

In November 2023, we entered into an Open Market Sale AgreementSM, or the Sales Agreement, with Jefferies LLC, or Jefferies, under which we may, from time to time, issue and sell shares of our common stock having an aggregate sales proceeds of up to $300.0 million, in a series of one or more at-the-market equity offerings, or the 2023 ATM Program. Any shares will be sold pursuant to the New Registration Statement and the sales agreement prospectus filed therewith, which covers the offer and sale of shares of our common stock under the 2023 ATM Program having an aggregate offering price of up to $200.0 million of the $300.0 million authorized under the Sales Agreement. If we wish to offer and sell additional shares of our common stock under the Sales Agreement in excess of the $200.0 million registered under the New Registration Statement, for up to an additional $100.0 million, we must file with the SEC one or more additional prospectus supplements to register under the Securities Act, the offer and sale of any such additional shares of our common stock we wish to offer and sell from time to time under the Sales Agreement. Jefferies is not required to sell any specific share amounts but acts as our sales agent, using commercially reasonable efforts consistent with its normal trading and sales practices. We will pay Jefferies a commission equal to 3.0% of the aggregate gross proceeds we receive from each sale of our shares of common stock. Pursuant to the Sales Agreement, any shares will be sold pursuant to our shelf registration statement on Form S-3 (File No. 333-275321) filed with the SEC on November 3, 2023, including the base prospectus contained therein, as declared effective by the SEC on November 13, 2023. Our common stock will be sold at prevailing market prices at the time of the sale, and as a result, prices may vary. As of December 31, 2024,2025, we have not sold any shares of common stock under the 2023 ATM Program.

In FebruaryAugust 2024,2025, we issued and sold 22,560,00143,700,000 shares of our common stock, including 3,360,0005,700,000 shares pursuant to the exercise of the underwriters’ option to purchase additional shares, at a price to the public of $6.25$3.30 per share. Further, in lieu of common stock to certain investors, we sold pre-funded warrants to purchase 3,200,005 shares of common stock at a public offering price of $6.24999 per pre-funded warrant, which represents the per share public offering price of each share of common stock less the $0.00001 per share exercise price for each pre-funded warrant. As a result of the offering, we received approximately $150.9$138.4 million in net proceeds, after deducting underwriting discounts, commissions and estimated offering costs of $10.1approximately $5.8 million.

In accordance with Accounting Standards Codification, or ASC, 205-40, Going Concern, or ASC 205-40, we evaluated whether there are conditions and events, considered in the aggregate, that raise substantial doubt about our ability to continue as a going concern within one year after the date on which this Annual Report on Form 10-K is filed. Based on the our cash, cash equivalents, short-term investments, and related party short-term investments as of December 31, 2024,2025, our current and forecasted level of operations and forecasted cash flows, our ability to continue as a going concern is dependent upon our ability to obtain the necessary financing to meet our obligations and repay our liabilities arising from normal business operations when they come due. Management plans to provide for capital requirements through financing or other transactions, and selling shares under our “at the market offering” program. There can be no assurance that we will be able to raise additional capital to fund operations with terms acceptable to us, or at all. Because certain elements of our plans to mitigate the conditions that raised substantial doubt about our ability to continue as a going concern are outside of our control, including the ability to raise capital through an equity or other financing, those elements cannot be considered probable according to ASC 205-40, and therefore cannot be considered in the evaluation of mitigating factors. As a result, we concluded that substantial doubt exists about our ability to continue as a going concern for 12 months from the date these consolidated financial statements are issued.

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, 2025. 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, 2025.2025, except as set forth below.

We are advancing our in vivo programs to cure two of the largest genetic liver diseases, Wilson Diseasedisease and AATD. BothIn programsJune are2026, currentlywe received clearance of the CTA for PM577a, an investigational Prime Editor for Wilson disease, in lateNew stagesZealand, representing the first clinical authorization for one of pre-clinicalour developmentin vivo Prime Editing therapies and enabling the initiation of our global Phase 1/2 clinical trial. In July 2026, the FDA cleared our IND application for PM577a. The IND clearance opens participation in our global Phase 1/2 clinical trial to patients in the United States, where H1069Q is the single most common pathogenic variant causing Wilson disease. Additionally, we are on track for IND application submission and/or ClinicalCTA Trial Application filingsfiling in the firstthird halfquarter of 2026 for WilsonPM647 Disease and the middle of 2026 forin AATD. We intend to leverage the modularity of our platform to expeditiously and efficiently develop these programs supported by our universal liver lipid nanoparticle along with potential regulatory, clinical and other synergies from our modular technology.

In August 2025, we announced additional data from the first patient dosed and initial data from the second patient dosed in our Phase 1/2 trial in CGD. We continue to engage in regulatory dialogue with the FDA toward a potential Biologics License Application filingsubmission for PM359.PM359, which is planned for the first half of 2027. In June 2026, the FDA granted RMAT designation for PM359, which provides opportunities for intensive FDA guidance and potential expedited review during the program’s development.

Comparison of the Three Months Ended MarchJune 31,30, 2026 and 2025

The $6.5$8.0 million decrease in research and development expenses for the three months ended MarchJune 31,30, 2026 as compared to the three months ended MarchJune 31,30, 2025 was primarily driven by:

•$3.7$3.6 million decrease in personnel expenses, driven primarily by fewer R&Dpersonnel-related personnelcosts resulting from the workforce reduction announced in May 2025.2025;

The $4.1$2.1 million increasedecrease in general and administrative expenses for the three months ended MarchJune 31,30, 2026 as compared to the three months ended MarchJune 31,30, 2025 was primarily driven by a $5.7 million increase in professional and consultant fees, a majority of which are arbitration-related legal expenses. This was offset by a $1.6 million decrease in personnel expenses driven primarily by fewer G&A personnel resulting from the workforce reduction announced in May 2025.:

The change in fair value of related party short-term investment for the threesix months ended MarchJune 31,30, 2025 was the result of Beam’s stock price movement.

Since our inception, we have incurred significant operating losses. We expect to incur significant expenses and operating losses for the foreseeable future as we advance the preclinical development of our current research programs, commence the clinical development of any product candidates we may identify, and continue our platform development and early-stage research activities. We have not yet commercialized any products and we do not expect to generate revenue from sales of products for several years, if at all. To date, we have funded our operations primarily with proceeds from sales of preferred stock and from our public offerings and through payments from our collaboration partners. As of MarchJune 31,30, 2026, we had cash, cash equivalents, and investments of $135.5$95.1 million, excluding our restricted cash, or $149.2$108.8 million, including restricted cash.

In November 2023, we entered into the Sales Agreement with Jefferies under which we may, from time to time, issue and sell shares of our common stock having an aggregate sales proceeds of up to $300.0 million, in a series of one or more at-the-market equity offerings as part of our 2023 ATM Program. Any shares will be sold pursuant to the Registration Statement and the sales agreement prospectus filed therewith, which covers the offer and sale of shares of our common stock under the 2023 ATM Program having an aggregate offering price of up to $200.0 million of the $300.0 million authorized under the Sales Agreement. If we wish to offer and sell additional shares of our common stock under the Sales Agreement in excess of the $200.0 million registered under the Registration Statement, for up to an additional $100.0 million, we must file with the SEC one or more additional prospectus supplements to register under the Securities Act, the offer and sale of any such additional shares of our common stock we wish to offer and sell from time to time under the Sales Agreement. Jefferies is not required to sell any specific share amounts but acts as our sales agent, using commercially reasonable efforts consistent with its normal trading and sales practices. We will pay Jefferies a commission equal to 3.0% of the aggregate gross proceeds we receive from each sale of our shares of common stock. Our common stock will be sold at prevailing market prices at the time of the sale, and as a result, prices may vary. As of March 31, 2026, we have not sold any shares of common stock under the 2023 ATM Program.

Since our inception, we have incurred substantial losses. As of MarchJune 31,30, 2026, we had an accumulated deficit of $937.5$979.6 million and we expect to generate operating losses and negative operating cash flows for the foreseeable future. As stated above, as of MarchJune 31,30, 2026, we maintained cash, cash equivalents, and short-term investments of $135.5$95.1 million.

In accordance with ASC 205-40, we evaluated whether there are conditions and events, considered in the aggregate, that raise substantial doubt about our ability to continue as a going concern within one year after the date on which this Quarterly Report on Form 10-Q is filed. Based on the our cash, cash equivalents, and short-term investments as of MarchJune 31,30, 2026, our current and forecasted level of operations and forecasted cash flows, our ability to continue as a going concern is dependent upon our ability to obtain the necessary financing to meet our obligations and repay our liabilities arising from normal business operations when they come due. Management plans to provide for capital requirements through financing or other transactions, and selling shares under our “at the market offering” program. There can be no assurance that we will be able to raise additional capital to fund operations with terms acceptable to us, or at all. Because certain elements of our plans to mitigate the conditions that raised substantial doubt about our ability to continue as a going concern are outside of our control, including the ability to raise capital through an equity or other financing, those elements cannot be considered probable according to ASC 205-40, and therefore cannot be considered in the evaluation of mitigating factors. As a result, we concluded that substantial doubt exists about our ability to continue as a going concern for 12 months from the date these condensed consolidated financial statements are issued.

The condensed consolidated financial statements as of MarchJune 31,30, 2026 have been prepared under the assumption that we will continue as a going concern for the next 12 months and that contemplates the realization of assets and satisfaction of liabilities and commitments in the normal course of business. Our ability to continue as a going concern is dependent upon our uncertain ability to obtain additional capital, reduce expenditures and/or execute on itsour business plan. These condensed consolidated financial statements do not include any adjustments that might result from the outcome of this uncertainty.

Net cash used in operating activities for the threesix months ended MarchJune 31,30, 2026 was driven primarily by the following uses of cash:

•$1.9$3.9 million change in lease liabilities.liabilities;

•$8.9$18.1 million of non-cash amounts included in net loss, which primarily consisted of stock-based compensation expense, non-cash lease expense, and depreciation expense; and

Net cash used in operating activities for the threesix months ended MarchJune 31,30, 2025 was driven primarily by the following uses of cash:

•$1.4$2.4 million change in deferred revenue from— considerationrelated received from BMS in September 2024.party;

•$1.9$2.1 million change in accountslease payable.liabilities;

Net cash provided by investing activities for the threesix months ended MarchJune 31,30, 2026 was driven primarily by $43.6$67.7 million of maturities of marketable securities,investments, net of purchases.

Net cash used in investing activities for the threesix months ended MarchJune 31,30, 2025 was driven primarily by the following:

•$45.3$41.0 million of purchases of marketable securities,investments, net of maturities; and

Net cash provided by financing activities for the threesix months ended MarchJune 31,30, 2025 was driven by $6.0 million of proceeds received under our agreement with Cystic Fibrosis Foundation.

During the threesix months ended MarchJune 31,30, 2026, except for the minimum lease commitments disclosed in Note 6, Leases, to the unaudited condensed consolidated financial statements in this Quarterly Report on Form 10-Q, there were no significant changes to our contractual obligations and commitments described under Management’s Discussion and Analysis of Financial Condition and Results of Operations in our Annual Report on Form 10-K for the year ended December 31, 2025.

During the threesix months ended MarchJune 31,30, 2026, there were no material changes to our critical accounting policies and significant judgments described under Management’s Discussion and Analysis of Critical Accounting Policies and Significant Judgments and Estimates which are included in our Annual Report on Form 10-K for the year ended December 31, 2025.