Korro Bio, Inc.

Previous wording

Since inception, we have incurred significant operating losses. Our net loss was $19.6 million and $23.4 million for the three months ended March 31, 2026 and 2025, respectively. As of March 31, 2026, we had an accumulated deficit of $403.5 million. We have financed our operations primarily through private placements of our convertible preferred stock and common stock, and sales under our ATM offering program. 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, and recently, a $30.9 million impairment charge in the fourth quarter of 2025 related to our operating lease right-of-use asset and fixed assets. We expect to continue to incur significant expenses, increasing operating losses, and negative operating cash flows for the foreseeable future. The net losses we incur may fluctuate significantly from quarter to quarter. We anticipate that our expenses will increase substantially if and as we:

Current wording

Since inception, we have incurred significant operating losses. Our net loss was $38.5 million and $49.2 million for the six months ended June 30, 2026 and 2025, respectively. As of June 30, 2026, we had an accumulated deficit of $422.4 million. We have financed our operations primarily through private placements of our convertible preferred stock and common stock, and sales under our ATM offering program. 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, and recently, a $30.9 million impairment charge in the fourth quarter of 2025 related to our operating lease right-of-use asset and fixed assets. We expect to continue to incur significant expenses, increasing operating losses, and negative operating cash flows for the foreseeable future. The net losses we incur may fluctuate significantly from quarter to quarter. We anticipate that our expenses will increase substantially if and as we:

Previous wording

progress our development candidates, including KRRO-121, through clinical development;

Current wording

progress our development candidates, including KRRO-121 and KRRO-111, through clinical development;

Previous wording

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, our lead candidates and development candidates. Because we have limited financial and managerial resources, we have prioritized our research programs and oligonucleotide optimization efforts in specific indications among many potential options. Specifically, our initial development programs target liver and central nervous systems indications, amongst others. As a result of this prioritization, we may forego or delay pursuit of opportunities with other lead candidates or development 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. Our resource allocation decisions may cause us to fail to capitalize on viable commercial products or profitable market opportunities. For example, KRRO-110, which used an LNP delivery system, did not reach projected levels of protein in patients in our now terminated Phase 1/2a REWRITE clinical trial for AATD and we have since transitioned to a GalNAc-conjugated delivery system for our AATD program. Our spending on current and future research and development programs, lead candidates, and development candidates for specific indications may not yield any commercially viable products.

Current wording

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, our lead candidates and development candidates. Because we have limited financial and managerial resources, we have prioritized our research programs and REO optimization efforts in specific indications among many potential options. Specifically, our initial development programs target liver and central nervous systems indications, amongst others. As a result of this prioritization, we may forego or delay pursuit of opportunities with other lead candidates or development 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. Our resource allocation decisions may cause us to fail to capitalize on viable commercial products or profitable market opportunities. For example, KRRO-110, which used an LNP delivery system, did not reach projected levels of protein in patients in our now terminated Phase 1/2a REWRITE clinical trial for AATD and we have since transitioned to a GalNAc-conjugated delivery system for our AATD program and are now developing KRRO-111, a GalNAc-conjugated REO for AATD. Our spending on current and future research and development programs, lead candidates, and development candidates for specific indications may not yield any commercially viable products.

Previous wording

As of March 31, 2026, our cash, cash equivalents and marketable securities were $157.1 million, excluding restricted cash, or $160.5 million, including restricted cash. We believe our existing cash, cash equivalents and marketable securities will be sufficient to fund our operating expenses and capital expenditure requirements through several value-creating milestones and into the second half of 2028. However, our operating plan may change as a result of factors currently unknown, and expectations regarding our cash runway and ability to reach data inflection points are based on numerous assumptions that may prove to be untrue. As a result, we may be required to raise capital sooner than anticipated and our exposure to certain contingent liabilities and contractual obligations may be greater than anticipated. Our future capital requirements will depend on many other 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.”

Current wording

As of June 30, 2026, our cash, cash equivalents and marketable securities were $137.9 million, excluding restricted cash, or $140.3 million, including restricted cash. We believe our existing cash, cash equivalents and marketable securities will be sufficient to fund our operating expenses and capital expenditure requirements through several value-creating milestones and into the second half of 2028. However, our operating plan may change as a result of factors currently unknown, and expectations regarding our cash runway and ability to reach data inflection points are based on numerous assumptions that may prove to be untrue. As a result, we may be required to raise capital sooner than anticipated and our exposure to certain contingent liabilities and contractual obligations may be greater than anticipated. Our future capital requirements will depend on many other 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.”

Previous wording

We did not reach projected levels of protein in patients in our now terminated Phase 1/2a REWRITE clinical trial of KRRO-110 for AATD and have transitioned to GalNAc-conjugated delivery for our AATD program, and may experience delays in developing a potential treatment for AATD. We have not completed any clinical trials nor reported any clinical trial results for any of our proposed delivery methods or RNA editing approaches. Any favorable results we may have from our earlier preclinical studies may not be predictive of results that may be observed in later preclinical studies or clinical trials.

Current wording

We did not reach projected levels of protein in patients in our now terminated Phase 1/2a REWRITE clinical trial of KRRO-110 for AATD and have transitioned to KRRO-111, a GalNAc-conjugated delivery for our AATD program, and may experience delays in developing a potential treatment for AATD. We have not completed any clinical trials nor reported any clinical trial results for any of our proposed delivery methods or RNA editing approaches. Any favorable results we may have from our earlier preclinical studies may not be predictive of results that may be observed in later preclinical studies or clinical trials.

Previous wording

The scientific evidence to support the feasibility of developing development candidates using our proprietary RNA editing technology is both preliminary and limited. We dosed very few participants in our now terminated Phase 1/2a REWRITE clinical trial of KRRO-110 for AATD. Although we observed functional protein in AATD patients following a single administration of KRRO-110, we did not reach projected levels of protein in patients as of the data cut off date. We have not completed any clinical trials for any of our proposed delivery methods or RNA editing approaches, and we have transitioned from LNP to GalNAc-conjugated delivery for our AATD program. Accordingly, we may experience delays in developing a potential treatment for AATD. In the future, we may use other delivery modalities to deliver our other lead candidates. While LNPs have been validated clinically to deliver oligonucleotides, such as siRNA, they were not clinically proven to deliver oligonucleotides for RNA editing, such as KRRO-110 and our other lead candidates. Similarly, while GalNAc-conjugated delivery has been validated in multiple FDA-approved oligonucleotide therapeutics, there are no FDA-approved GalNAc-conjugated RNA editing oligonucleotide therapeutics. Both of our most advanced programs, KRRO-121 and our AATD program, utilize GalNAc-conjugated delivery. If GalNAc-conjugated delivery fails to effectively deliver our RNA editing oligonucleotides, multiple programs in our pipeline could be adversely affected.

Current wording

The scientific evidence to support the feasibility of developing development candidates using our proprietary RNA editing technology is both preliminary and limited. We dosed very few participants in our now terminated Phase 1/2a REWRITE clinical trial of KRRO-110 for AATD. Although we observed functional protein in AATD patients following a single administration of KRRO-110, we did not reach projected levels of protein in patients as of the data cut off date. We have not completed any clinical trials for any of our proposed delivery methods or RNA editing approaches, and we have transitioned from LNP to GalNAc-conjugated delivery for KRRO-111, our REO for our AATD program. Accordingly, we may experience delays in developing a potential treatment for AATD. In the future, we may use other delivery modalities to deliver our other lead candidates. While LNPs have been validated clinically to deliver oligonucleotides, such as siRNA, they were not clinically proven to deliver oligonucleotides for RNA editing, such as KRRO-110 and our other lead candidates. Similarly, while GalNAc-conjugated delivery has been validated in multiple FDA-approved oligonucleotide therapeutics, there are no FDA-approved GalNAc-conjugated REO therapeutics. Both of our most advanced programs, KRRO-121 and KRRO-111, utilize GalNAc-conjugated delivery. If GalNAc-conjugated delivery fails to effectively deliver our REOs, multiple programs in our pipeline could be adversely affected.

Previous wording

We have concentrated a significant portion of our current resources and efforts on the advancement of KRRO-121, our lead development candidate for the treatment of hyperammonemia, including UCD and HE. KRRO-121 is in preclinical development and has not been tested in humans. KRRO-121 utilizes GalNAc-conjugated delivery and is designed to generate a stabilized, de novo variant of GS with enhanced ammonia clearance capacity. We anticipate submitting a regulatory filing to enable commencement of a first-in-human clinical trial in the second half of 2026. However, there can be no assurance that KRRO-121 will demonstrate safety or efficacy in humans, that our regulatory filing will be accepted, or that we will be able to initiate or complete clinical trials on our anticipated timeline. If KRRO-121 fails to demonstrate safety or efficacy, or if we experience significant delays in its regulatory filing or clinical development, our business, financial condition, results of operations and prospects would be materially and adversely affected. Following the termination of our REWRITE clinical program investigating KRRO-110 for AATD, KRRO-121 is our only nominated development candidate, which increases the concentration of risk in a single program. Our other programs, including our AATD GalNAc-conjugated program, our longevity and liver health program targeting AMPKγ1, and our ALS program targeting TDP-43, are in earlier stages of preclinical development and may not advance to clinical development on a timely basis, or at all.

Current wording

We have concentrated a significant portion of our current resources and efforts on the advancement of KRRO-121, our lead development candidate for the treatment of hyperammonemia, including UCD and HE. KRRO-121 is in preclinical development and has not been tested in humans. KRRO-121 utilizes GalNAc-conjugated delivery and is designed to generate a stabilized, de novo variant of GS with enhanced ammonia clearance capacity. We anticipate submitting a regulatory filing to enable commencement of a first-in-human clinical trial in the second half of 2026. However, there can be no assurance that KRRO-121 will demonstrate safety or efficacy in humans, that our regulatory filing will be accepted, or that we will be able to initiate or complete clinical trials on our anticipated timeline. If KRRO-121 fails to demonstrate safety or efficacy, or if we experience significant delays in its regulatory filing or clinical development, our business, financial condition, results of operations and prospects would be materially and adversely affected. Following the termination of our REWRITE clinical program investigating KRRO-110 for AATD, we only recently nominated KRRO-111, our GalNac-conjugated REO for AATD and it is in early stages of clinical development. Our other programs, including our longevity and liver health program targeting AMPKγ1, and our ALS program targeting TDP-43, are in earlier stages of preclinical development and may not advance to clinical development on a timely basis, or at all.

Previous wording

The success of our business depends primarily upon our ability to identify, develop and commercialize development candidates. We are very early in our development efforts and have focused our research and development efforts to date on developing OPERA, our RNA editing platform, and identifying our initial targeted disease indications. We currently only have one nominated development candidate in our pipeline, KRRO-121, as we terminated further development of KRRO-110 after it failed to reach projected levels of protein in our first in-human clinical trial. Although we believe we can demonstrate many of the key advantages of RNA editing, because we are very 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 any candidates we successfully develop. Such uncertainties include, but are not limited to, the level of editing efficiency needed in a target tissue type to achieve a clinical benefit, and associated safety of our edits in humans. We have also not yet shown that preclinical editing activity can result in clinically important effects, nor that the data generated by our preclinical studies can translate into positive results in clinical trials.

Current wording

The success of our business depends primarily upon our ability to identify, develop and commercialize development candidates. We are very early in our development efforts and have focused our research and development efforts to date on developing OPERA, our RNA editing platform, and identifying our initial targeted disease indications. We currently only have two nominated development candidates in our pipeline, KRRO-121, and more recently, KRRO-111, as we terminated further development of KRRO-110 after it failed to reach projected levels of protein in our first in-human clinical trial. Although we believe we can demonstrate many of the key advantages of RNA editing, because we are very 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 any candidates we successfully develop. Such uncertainties include, but are not limited to, the level of editing efficiency needed in a target tissue type to achieve a clinical benefit, and associated safety of our edits in humans. We have also not yet shown that preclinical editing activity can result in clinically important effects, nor that the data generated by our preclinical studies can translate into positive results in clinical trials.

Previous wording

We are very early in our development of development candidates and have focused our efforts to date primarily on platform development, discovery, research, and preclinical development and had only dosed a small number of participants in our now terminated Phase 1/2a REWRITE clinical trial of KRRO-110 for AATD. Our development candidate, KRRO-121, is advancing toward a regulatory filing anticipated in the second half of 2026. All of our other programs are still in the research or preclinical stage of development. Our ability to generate product revenues, which we do not expect will occur for many years, if ever, will depend heavily on the successful development, marketing approval and eventual commercialization of our development candidates, which may never occur. We have not yet generated revenue from product sales or otherwise, and we may never be able to develop or commercialize a marketable product.

Current wording

We are very early in our development of development candidates and have focused our efforts to date primarily on platform development, discovery, research, and preclinical development and had only dosed a small number of participants in our now terminated Phase 1/2a REWRITE clinical trial of KRRO-110 for AATD. Our development candidate, KRRO-121, is advancing toward a regulatory filing anticipated in the second half of 2026 and we only recently nominated KRRO-111 as our GalNac-conjugated REO for AATD. All of our other programs are still in the research or preclinical stage of development. Our ability to generate product revenues, which we do not expect will occur for many years, if ever, will depend heavily on the successful development, marketing approval and eventual commercialization of our development candidates, which may never occur. We have not yet generated revenue from product sales or otherwise, and we may never be able to develop or commercialize a marketable product.

Previous wording

Our development candidates are based upon new discoveries, technologies and therapeutic approaches. Key participants in pharmaceutical marketplaces, such as physicians, third-party payors and consumers, may not adopt a product intended to improve therapeutic results that is based on the technology employed by oligonucleotides. As a result, it may be more difficult for us to convince the medical community and third-party payors to accept and use our product, or to provide favorable reimbursement.

Current wording

Our development candidates are based upon new discoveries, technologies and therapeutic approaches. Key participants in pharmaceutical marketplaces, such as physicians, third-party payors and consumers, may not adopt a product intended to improve therapeutic results that is based on the technology employed by REOs. As a result, it may be more difficult for us to convince the medical community and third-party payors to accept and use our product, or to provide favorable reimbursement.

Previous wording

Because we are developing oligonucleotides, which are considered a relatively new class of drugs, there is increased risk that the outcome of our clinical trials will not be sufficient to obtain regulatory approval.

Current wording

Because we are developing REOs, which are considered a relatively new class of drugs, there is increased risk that the outcome of our clinical trials will not be sufficient to obtain regulatory approval.

Previous wording

The FDA and comparable ex-U.S. regulatory agencies have relatively limited experience with oligonucleotides, which may increase the complexity, uncertainty and length of the regulatory review process for any development candidates. Even though the FDA issued two draft guidance documents in December 2021 relating to IND submissions for individualized antisense oligonucleotide drugs for severely debilitating or life-threatening genetic diseases, one with clinical focus, the other with chemistry manufacturing and controls focus, and in June 2024 final guidance on clinical pharmacology considerations for the development of oligonucleotide therapeutics, the FDA and its foreign counterparts have not yet established any definitive policies, practices or guidelines in relation to overall development considerations for RNA editing oligonucleotide therapies. The general lack of policies, practices or guidelines specific to oligonucleotides may hinder or slow review by the FDA or other foreign regulatory agencies of any regulatory filings that we may submit. Moreover, the FDA or other foreign regulatory agencies may respond to these submissions by defining requirements we may not have anticipated. Addressing such requirements could lead to significant delays in the development of our development candidates. In addition, because there may be approved treatments for some of the diseases for which we may seek approval, in order to receive regulatory approval, we may need to demonstrate through clinical trials that the development candidates we develop to treat these diseases, if any, are not only safe and effective, but safer or more effective than existing products. Furthermore, in recent years, there has been increased public and political pressure on the FDA with respect to the approval process for new drugs. As a result of the foregoing factors, we may never receive regulatory approval to market and commercialize any development candidate. Even if we obtain regulatory approval, the approval may be for disease indications or patient populations that are not as broad as we intended or desired or may require labeling that includes significant use or distribution restrictions or safety warnings. We may be required to perform additional or unanticipated clinical trials to obtain regulatory approval or be subject to additional post-marketing studies or other requirements to maintain such approval. As a result, we may never succeed in developing a marketable product, we may not become profitable and the value of our common stock could decline.

Current wording

The FDA and comparable ex-U.S. regulatory agencies have relatively limited experience with oligonucleotides, which may increase the complexity, uncertainty and length of the regulatory review process for any development candidates. Even though the FDA issued two draft guidance documents in December 2021 relating to IND submissions for individualized antisense oligonucleotide drugs for severely debilitating or life-threatening genetic diseases, one with clinical focus, the other with chemistry manufacturing and controls focus, and in June 2024 final guidance on clinical pharmacology considerations for the development of oligonucleotide therapeutics, the FDA and its foreign counterparts have not yet established any definitive policies, practices or guidelines in relation to overall development considerations for REO therapies. The general lack of policies, practices or guidelines specific to oligonucleotides may hinder or slow review by the FDA or other foreign regulatory agencies of any regulatory filings that we may submit. Moreover, the FDA or other foreign regulatory agencies may respond to these submissions by defining requirements we may not have anticipated. Addressing such requirements could lead to significant delays in the development of our development candidates. In addition, because there may be approved treatments for some of the diseases for which we may seek approval, in order to receive regulatory approval, we may need to demonstrate through clinical trials that the development candidates we develop to treat these diseases, if any, are not only safe and effective, but safer or more effective than existing products. Furthermore, in recent years, there has been increased public and political pressure on the FDA with respect to the approval process for new drugs. As a result of the foregoing factors, we may never receive regulatory approval to market and commercialize any development candidate. Even if we obtain regulatory approval, the approval may be for disease indications or patient populations that are not as broad as we intended or desired or may require labeling that includes significant use or distribution restrictions or safety warnings. We may be required to perform additional or unanticipated clinical trials to obtain regulatory approval or be subject to additional post-marketing studies or other requirements to maintain such approval. As a result, we may never succeed in developing a marketable product, we may not become profitable and the value of our common stock could decline.

Previous wording

We and the third parties upon which we rely face a variety of evolving threats, which could cause cybersecurity incidents or data breaches. Cybersecurity incidents and data breaches are increasing in their frequency, sophistication and intensity, and have become increasingly difficult to detect. Cybersecurity incidents and data breaches could include wrongful conduct by hostile foreign governments, industrial espionage, wrongful conduct by employees or vendors, human error, wire fraud and other forms of cyber fraud, the deployment of harmful malware or ransomware, denial-of-service attacks, social engineering fraud (including successful phishing attacks) or other means to threaten data confidentiality, integrity and availability. A cybersecurity incident or data breach could cause serious negative consequences for us, including, without limitation, the disruption of operations, the misappropriation of confidential business information, including financial information, trade secrets, financial loss and the disclosure of corporate strategic plans.

Current wording

We and the third parties upon which we rely face a variety of evolving threats, which could cause cybersecurity incidents or data breaches. Cybersecurity incidents and data breaches are increasing in their frequency, sophistication and intensity, and have become increasingly difficult to detect. Cybersecurity incidents and data breaches could include wrongful conduct by hostile foreign governments, industrial espionage, wrongful conduct by employees or vendors, human error, wire fraud and other forms of cyber fraud, the deployment of harmful malware or ransomware, denial-of-service attacks, social engineering fraud (including successful phishing attacks) or other means to threaten data confidentiality, integrity and availability.

Previous wording

Like other companies in our industry, we and our third party vendors, have experienced, or may experience, threats and cybersecurity incidents relating to our and our third-party vendors’ information systems and infrastructure. Although we devote resources to protect our information systems, there can be no assurance that our efforts will prevent cybersecurity incidents or data breaches that could result in business, legal, financial or reputational harm to us, or would have a material adverse effect on our results of operations and financial condition. Attempts to disrupt or gain unauthorized access to our and our third-party vendors’ information systems from malicious third parties or insider threats may incorporate widely varying and frequently changing tactics, which may be enhanced or facilitated by artificial intelligence. Further, our contracts may not contain limitations of liability, and even where they do, there can be no assurance that limitations of liability in our contracts are sufficient to protect us from liabilities, damages, or claims related to our privacy and data security obligations. Although we maintain cyber liability insurance, this insurance may not provide adequate coverage against potential liabilities related to any experienced cybersecurity incident or breach. For additional information on our cybersecurity obligations as well as our cybersecurity program, see Item 1 “Business—Government Regulation—Privacy and Cybersecurity” and Item 1C “Cybersecurity” in the 2025 10-K.

Current wording

Although we devote resources to protect our information systems, there can be no assurance that our efforts will prevent cybersecurity incidents or data breaches that could result in business, legal, financial or reputational harm to us, or would have a material adverse effect on our results of operations and financial condition. Attempts to disrupt or gain unauthorized access to our and our third-party vendors’ information systems from malicious third parties or insider threats may incorporate widely varying and frequently changing tactics, which may be enhanced or facilitated by artificial intelligence. Further, our contracts may not contain limitations of liability, and even where they do, there can be no assurance that limitations of liability in our contracts are sufficient to protect us from liabilities, damages, or claims related to our privacy and data security obligations. Although we maintain cyber liability insurance, this insurance may not provide adequate coverage against potential liabilities related to any experienced cybersecurity incident or breach. For additional information on our cybersecurity obligations as well as our cybersecurity program, see Item 1 “Business—Government Regulation—Privacy and Cybersecurity” and Item 1C “Cybersecurity” in the 2025 10-K.

Previous wording

We have not yet manufactured our development candidates on a commercial scale, and may not be able to do so for any of our development candidates. We currently rely on third parties in the supply and manufacture of materials for our research, preclinical and clinical activities and may continue to do so for the foreseeable future, including if we received regulatory approval for any development candidate. We may do the same for the commercial supply of our drug product. We use third parties to perform additional steps in the manufacturing process, such as the filling, finishing and labeling of vials and storage of our development candidates and we expect to do so for the foreseeable future. There can be no assurance that our supply of research, preclinical and clinical development drug candidates and other materials will not be limited, interrupted or restricted or will be of satisfactory quality or continue to be available at acceptable prices. Replacement of any of the third parties we may engage could require significant effort and expertise because there may be a limited number of qualified replacements. In addition, raw materials, reagents, and components used in the manufacturing process, particularly those for which we have no other source or supplier, may not be available, may not be suitable or acceptable for use due to material or component defects, or may introduce variability into the supply of our development candidates. Furthermore, with the increase of companies developing nucleic acid therapeutics, there may be increased competition for the supply of the raw materials that are necessary to make our oligonucleotides, which could severely impact the manufacturing of our development candidates.

Current wording

We have not yet manufactured our development candidates on a commercial scale, and may not be able to do so for any of our development candidates. We currently rely on third parties in the supply and manufacture of materials for our research, preclinical and clinical activities and may continue to do so for the foreseeable future, including if we received regulatory approval for any development candidate. We may do the same for the commercial supply of our drug product. We use third parties to perform additional steps in the manufacturing process, such as the filling, finishing and labeling of vials and storage of our development candidates and we expect to do so for the foreseeable future. There can be no assurance that our supply of research, preclinical and clinical development drug candidates and other materials will not be limited, interrupted or restricted or will be of satisfactory quality or continue to be available at acceptable prices. Replacement of any of the third parties we may engage could require significant effort and expertise because there may be a limited number of qualified replacements. In addition, raw materials, reagents, and components used in the manufacturing process, particularly those for which we have no other source or supplier, may not be available, may not be suitable or acceptable for use due to material or component defects, or may introduce variability into the supply of our development candidates. Furthermore, with the increase of companies developing nucleic acid therapeutics, there may be increased competition for the supply of the raw materials that are necessary to make our REOs, which could severely impact the manufacturing of our development candidates.

Previous wording

As of March 31, 2026, we had 49 full-time employees, including 37 who hold Ph.D. degrees or other advanced degrees; 33 employees are engaged in research and development and 16 employees are engaged in management or general and administrative activities. In May 2025, we announced a workforce reduction and organizational streamlining and in November 2025, we announced a further workforce reduction to extend our cash runway. In connection with the growth and advancement of our pipeline, we expect that we will need to increase the number of our employees and the scope of our operations, particularly in the areas of drug development, regulatory affairs, and as any development candidates near later stage clinical trials and potential commercialization by us, and sales and marketing. To manage our anticipated future growth, we must continue to implement and improve our managerial, operational and financial systems, expand our facilities, and continue to recruit and train additional qualified personnel. Our workforce reduction may make these efforts more challenging. Due to our limited financial resources and the limited experience of our management team in managing a company with such anticipated growth, we may not be able to effectively manage the expected future expansion of our operations or recruit and train additional qualified personnel. Any inability to manage growth could delay the execution of our business plans or disrupt our operations.

Current wording

As of June 30, 2026, we had 57 full-time employees, including 42 who hold Ph.D. degrees or other advanced degrees; 40 employees are engaged in research and development and 17 employees are engaged in management or general and administrative activities. In May 2025, we announced a workforce reduction and organizational streamlining and in November 2025, we announced a further workforce reduction to extend our cash runway. In connection with the growth and advancement of our pipeline, we expect that we will need to increase the number of our employees and the scope of our operations, particularly in the areas of drug development, regulatory affairs, and as any development candidates near later stage clinical trials and potential commercialization by us, and sales and marketing. To manage our anticipated future growth, we must continue to implement and improve our managerial, operational and financial systems, expand our facilities, and continue to recruit and train additional qualified personnel. Our workforce reduction may make these efforts more challenging. Due to our limited financial resources and the limited experience of our management team in managing a company with such anticipated growth, we may not be able to effectively manage the expected future expansion of our operations or recruit and train additional qualified personnel. Any inability to manage growth could delay the execution of our business plans or disrupt our operations.

Previous wording

The future growth of our business may depend in part on our ability to in-license or otherwise acquire the rights to additional development candidates and technologies. 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. In order to market our development candidates, we may find it necessary or prudent to obtain licenses from 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 to develop or commercialize our development candidates or other key technologies. We may also require licenses from third parties for certain additional technologies, including technologies relating to RNA editing, such as guide RNA modification, or target sequences as well as delivery technologies for development candidates we may develop. 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 development candidates or allow our competitors or other third parties the chance to access technology that is important to our business.

Current wording

The future growth of our business may depend in part on our ability to in-license or otherwise acquire the rights to additional development candidates and technologies. 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 field of gene editing technology and filing patent applications potentially relevant to our business. In order to market our development candidates, we may find it necessary or prudent to obtain licenses from 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 to develop or commercialize our development candidates or other key technologies. We may also require licenses from third parties for certain additional technologies, including technologies relating to RNA editing, such as guide RNA modification, or target sequences as well as delivery technologies for development candidates we may develop. 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 development candidates or allow our competitors or other third parties the chance to access technology that is important to our business.

Previous wording

We are incurring and expect to continue to incur significant legal, accounting and other expenses operating as a public company, including costs associated with public company reporting obligations under the Exchange Act. Our management team includes some individuals who have not previously managed and operated a public company. These executive officers and other personnel will need to devote substantial time to gaining expertise related to public company reporting requirements and compliance with applicable laws and regulations to ensure that we continue to comply with all of these requirements. Any changes we make to comply with these obligations may not be sufficient to allow us to satisfy our obligations as a public company on a timely basis, or at all. These reporting requirements, rules and regulations, coupled with the increase in potential litigation exposure associated with operating our current business as a public company, could also make it more difficult for us to attract and retain qualified persons to serve on the board of

Current wording

We are incurring and expect to continue to incur significant legal, accounting and other expenses operating as a public company, including costs associated with public company reporting obligations under the Exchange Act. Our management team includes some individuals who have not previously managed and operated a public company. These executive officers and other personnel will need to devote substantial time to gaining expertise related to public company reporting requirements and compliance with applicable laws and regulations to ensure that we continue to comply with all of these requirements. Any changes we make to comply with these obligations may not be sufficient to allow us to satisfy our obligations as a public company on a timely basis, or at all. These reporting requirements, rules and regulations, coupled with the increase in potential litigation exposure associated with operating our current business as a public company, could also make it more difficult for us to attract and retain qualified persons to serve on the board of directors or on board committees or to serve as executive officers, or to obtain certain types of insurance, including directors’ and officers’ insurance, on acceptable terms.

Previous wording

Provisions in our restated certificate of incorporation, as amended, and bylaws may discourage, delay or prevent a merger, acquisition or other change in control that stockholders may consider favorable, including transactions in which our common stockholders might otherwise receive a premium price for their shares. These provisions could also limit the price that investors might be willing to pay in the future for shares of our common stock, thereby depressing the market price of our common stock. In addition, because our board of directors will be responsible for appointing the members of our management team, these provisions may frustrate or prevent any attempts by our stockholders to replace or remove our current management by making it more difficult for stockholders to replace members of our board of directors. Among other things, these provisions:

Current wording

Provisions in our restated certificate of incorporation, as amended, and bylaws may discourage, delay or prevent a merger, acquisition or other change in control that stockholders may consider favorable, including transactions in which our common stockholders might otherwise receive a premium price for their shares. These provisions could also limit the price that investors might be willing to pay in the future for shares of our common stock, thereby depressing the market price of our common stock. In addition, because our board of directors will be responsible for appointing the members of our management team, these provisions may frustrate

Previous wording

Our business may be impacted by macroeconomic conditions, including inflation, rising interest rates and volatile market conditions, and other uncertainties beyond our control, including geopolitical events, such as recent U.S. and Israeli military action in Iran, and effects thereof.

Current wording

Our business may be impacted by macroeconomic conditions, including inflation, rising interest rates and volatile market conditions, and other uncertainties beyond our control, including geopolitical events, such as ongoing U.S. and Israeli military action in Iran, and effects thereof.

Previous wording

Our ability to effectively run our business could be adversely affected by general conditions in the global economy and in the financial services industry. Various macroeconomic factors could adversely affect our business, including fears concerning the banking sector (such as what occurred in 2023), changes in inflation, interest rates and overall economic conditions and uncertainties (including as a result of announced tariffs or other policy changes by the current U.S. administration). Actual events involving limited liquidity, defaults, non-performance or other adverse developments that affect financial institutions, transactional counterparties or other companies in the financial services industry or the financial services industry generally, or concerns or rumors about any events of these kinds or other similar risks, have in the past and may in the future lead to market-wide liquidity problems. A severe or prolonged economic downturn could result in a variety of risks, including our ability to raise additional funding on a timely basis or on acceptable terms. A weak or declining economy could also impact third parties upon whom we depend to run our business. Although we assess our banking relationships as we believe necessary or appropriate, our access to funding sources in amounts adequate to finance or capitalize our current and projected future business operations could be significantly impaired by factors that affect us, the financial institutions with which we have arrangements directly, or the financial services industry or economy in general. Moreover, significant political, trade, regulatory developments, and other circumstances beyond our control, such as geopolitical events, like the recent U.S. and Israeli military action in Iran and effects thereof, could have a material adverse effect on our financial condition or results of operations.

Current wording

(including as a result of announced tariffs or other policy changes by the current U.S. administration). Actual events involving limited liquidity, defaults, non-performance or other adverse developments that affect financial institutions, transactional counterparties or other companies in the financial services industry or the financial services industry generally, or concerns or rumors about any events of these kinds or other similar risks, have in the past and may in the future lead to market-wide liquidity problems. A severe or prolonged economic downturn could result in a variety of risks, including our ability to raise additional funding on a timely basis or on acceptable terms. A weak or declining economy could also impact third parties upon whom we depend to run our business. Although we assess our banking relationships as we believe necessary or appropriate, our access to funding sources in amounts adequate to finance or capitalize our current and projected future business operations could be significantly impaired by factors that affect us, the financial institutions with which we have arrangements directly, or the financial services industry or economy in general. Moreover, significant political, trade, regulatory developments, and other circumstances beyond our control, such as geopolitical events, like the ongoing U.S. and Israeli military action in Iran and effects thereof, could have a material adverse effect on our financial condition or results of operations.

Previous wording

During the three months ended March 31, 2026, none of our officers (as defined in Rule 16a-1(f) under the Exchange Act) or directors informed us that they adopted contracts, instructions or written plans for the purchase or sale of our securities that were intended to satisfy the affirmative defense conditions of Rule 10b5-1(c) under the Exchange Actor a trading plan not intended to satisfy the affirmative defense conditions of Rule 10b5-1(c) under the Exchange Act.

Current wording

During the three months ended June 30, 2026, the following officers (as defined in Rule 16a-1(f) under the Exchange Act) adopted, amended or terminated contracts, instructions or written plans for the purchase or sale of our securities that were intended to satisfy the affirmative defense conditions of Rule 10b5-1(c) under the Exchange Act (each, a “Rule 10b5-1 plan”): On May 28, 2026, Loïc Vincent, our Chief Scientific Officer, terminated a Rule 10b5-1 plan providing for the potential sale of up to 7,292 shares of our common stock issuable upon the exercise of stock options, andon June 7, 2026, Dr. Vincent adopted a Rule 10b5-1 plan providing for the potential sale of up to 21,715 shares of our common stock issuable upon the vesting and settlement of restricted stock units, as well as up to 4,584 shares of our common stock issuable upon the exercise of stock options; this plan is scheduled to expire on February 1, 2028. On June 8, 2026, Oliver Dolan, our Senior Vice President, Finance, adopted a Rule 10b5-1 plan providing for the potential sale of up to 21,482 shares of our common stock issuable upon the vesting and settlement of restricted stock units; this plan is scheduled to expire on June 4, 2027. During the three months ended June 30, 2026, none of our other officers or directors informed us that they adopted, modified orterminated a Rule 10b5-1 plan or a trading plan not intended to satisfy the affirmative defense conditions of Rule 10b5-1(c) under the Exchange Act.