Dyne Therapeutics, Inc.

Previous wording

The following discussion and analysis of our financial condition and results of operations should be read in conjunction with our condensed consolidated financial statements and related notes appearing elsewhere in this Quarterly Report on Form 10-Q, or this Quarterly Report, and our audited condensed consolidated financial statements and related notes for the year ended December 31, 2024, included in our Annual Report on Form 10-K filed with the Securities and Exchange Commission, or SEC, on February 27, 2025. Some of the information contained in this discussion and analysis or set forth elsewhere in this Quarterly Report, including information with respect to our plans and strategy for our business, includes forward-looking statements that involve risks and uncertainties. As a result of many factors, including those factors set forth in the “Risk Factors” section of this Quarterly Report, our actual results could differ materially from the results described in, or implied by, the forward-looking statements contained in the following discussion and analysis.

Current wording

The following discussion and analysis of our financial condition and results of operations should be read in conjunction with our condensed consolidated financial statements and related notes appearing elsewhere in this Quarterly Report on Form 10-Q, or this Quarterly Report, and our audited consolidated financial statements and related notes for the year ended December 31, 2025, included in our Annual Report on Form 10-K filed with the Securities and Exchange Commission, or SEC, on March 2, 2026. Some of the information contained in this discussion and analysis or set forth elsewhere in this Quarterly Report, including information with respect to our plans and strategy for our business, includes forward-looking statements that involve risks and uncertainties. As a result of many factors, including those factors set forth in the “Risk Factors” section of this Quarterly Report, our actual results could differ materially from the results described in, or implied by, the forward-looking statements contained in the following discussion and analysis.

Previous wording

We are a clinical-stage company focused on delivering functional improvement for people living with genetically driven neuromuscular diseases. Leveraging the modularity of our FORCE platform, we are developing targeted therapeutics that are designed to overcome limitations in delivery to muscle tissue and the central nervous system, or CNS. Our proprietary FORCE platform therapeutics consist of a payload that we rationally design to target the genetic basis of the disease we are seeking to treat, a linker and an antigen-binding fragment, or Fab, that we attach to the payload using the linker. With our FORCE platform, we have the flexibility to deploy different classes of payloads (such as oligonucleotides and enzymes) with specific mechanisms of action that modify target functions. We leverage this modularity to focus on neuromuscular diseases with high unmet need, with etiologic targets and with clear translational potential from preclinical disease models to well-defined clinical development and regulatory pathways.

Current wording

We are a clinical-stage company focused on delivering functional improvement for people living with genetically driven neuromuscular diseases. Our proprietary FORCE platform is designed to leverage the transferrin receptor 1, or TfR1, to deliver targeted therapeutics to muscle tissue and the central nervous system, or CNS. The FORCE platform utilizes an antigen-binding fragment antibody, or Fab, targeting TfR1 linked to a payload that we rationally design to target the genetic basis of the disease we are seeking to treat. With our FORCE platform, we have the flexibility to deploy different classes of payloads (such as oligonucleotides and enzymes) with specific mechanisms of action that modify target functions. We currently leverage this modularity to focus on neuromuscular diseases with high unmet need, with etiologic targets and with clear translational potential from preclinical disease models to well-defined clinical development and regulatory pathways.

Previous wording

Using our FORCE platform, we are assembling a broad portfolio of product candidates, including product candidates being developed for myotonic dystrophy type 1, or DM1, Duchenne muscular dystrophy, or DMD, facioscapulohumeral dystrophy, or FSHD, and Pompe disease. In addition, we plan to expand our portfolio through development efforts focused on rare skeletal muscle diseases, as well as cardiac and metabolic muscle diseases, including some with larger patient populations, and diseases involving the CNS. We have identified product candidates for each of our DM1, DMD, FSHD and Pompe programs that are in varying stages of preclinical and clinical development.

Current wording

Using our FORCE platform, we are assembling a broad portfolio of product candidates, including product candidates being developed for Duchenne muscular dystrophy, or DMD, myotonic dystrophy type 1, or DM1, facioscapulohumeral dystrophy, or FSHD, and Pompe disease. In addition, we plan to expand our portfolio through development efforts focused on diseases involving the CNS, rare skeletal muscle diseases, and cardiac and metabolic muscle diseases, including some with larger patient populations. We have identified product candidates for each of our DMD, DM1, FSHD and Pompe programs that are in varying stages of preclinical and clinical development.

Previous wording

Accelerated Approval planned for early in the third quarter of 2027. We began the U.S. site activation process in June 2025 and in September 2025, U.S. site activation began. In October 2025, U.S. patient enrollment and dosing were initiated. As of October 31, 2025, we have enrolled approximately half of the registrational expansion cohort. We continue to advance preparations for a Phase 3 clinical trial of z-basivarsen and plan to initiate the trial in the first quarter of 2026. We continue to pursue approval pathways for z-basivarsen outside of the U.S. We anticipate a potential launch of z-basivarsen in the first quarter of 2028, assuming we receive favorable data, priority review is granted, and FDA approval is received on the anticipated timeline.

Current wording

Z-basivarsen is being evaluated in the ACHIEVE trial, a global Phase 1/2 clinical trial designed to be registrational, and the HARMONIA trial, a global Phase 3 clinical trial designed to be confirmatory, which was initiated in March 2026. We have aligned with the FDA on the HARMONIA trial design and protocol. We have also reached our enrollment target of 60 participants in the registrational expansion cohort, or REC, of the ACHIEVE trial. We plan to allow any participants currently in screening to enroll if they meet all eligibility criteria. As a result, we expect to complete enrollment of more than 60 participants in the second quarter of 2026. We plan to announce data from the REC in the first quarter of 2027 to support a potential BLA submission to the FDA for U.S. Accelerated Approval early in the third quarter of 2027. We anticipate a potential U.S. launch of z-basivarsen in the first quarter of 2028, assuming we receive favorable data from the REC, priority review is granted, and FDA approval is received on the anticipated timeline. We continue to pursue approval pathways outside of the United States for z-basivarsen.

Previous wording

In June 2024 and June 2025, we announced new preclinical data for DYNE-302, our product candidate for FSHD, that demonstrated robust and durable DUX4 suppression and functional benefit in a mouse model. We generated these data using an innovative hTfR1/iFLExD mouse model we developed that expresses the human transferrin 1 receptor, or TfR1, and enables tunable DUX4 induction in skeletal muscle. In hTfR1/iFLExD mice, a single intravenous dose of DYNE-302 resulted in dose-dependent and robust reduction of the DUX4 transcriptome that lasted up to three months, with benefit on muscle structure. DYNE-302 also demonstrated prevention as well as reversal of muscle weakness. We are progressing DYNE-302 through IND/CTA-enabling studies.

Current wording

In June 2024 and June 2025, we announced preclinical data for DYNE-302, our product candidate for FSHD, that demonstrated robust and durable DUX4 suppression and functional benefit in a mouse model. We generated these data using an innovative hTfR1/iFLExD mouse model we developed that expresses TfR1 and enables tunable DUX4 induction in skeletal muscle. In hTfR1/iFLExD mice, a single intravenous dose of DYNE-302 resulted in dose-dependent and robust reduction of the DUX4 transcriptome that lasted up to three months, with benefit on muscle structure. DYNE-302 also demonstrated prevention and reversal of muscle weakness.

Previous wording

We are developing a product candidate, DYNE-401, to deliver an enzyme replacement therapy to address the deficiency of the lysosomal enzyme, GAA, that causes Pompe disease. We engineered FORCE-GAA by leveraging the FORCE platform and evaluated efficacyin vivo using hTfR1/6 Neo mice, that were developed by crossing the well-established 6 Neo mouse model of Pompe with mice expressing human transferrin receptor 1. Using this approach, intravenous, or IV, administration cleared glycogen in muscle and the CNS and normalized lysosomal size in hTfR1/6 Neo mice. This approach reduced serum neurofilament light chain, a biomarker of axonal injury, providing evidence of benefit in the CNS and displayed superior dose potency compared to GAA alone. Additional data with this approach supported the potential for monthly dosing which is less frequent than approved enzyme replacement therapies for Pompe.

Current wording

We are developing DYNE-401 for the treatment of Pompe disease. DYNE-401 is designed to deliver an enzyme replacement therapy to address the deficiency of the lysosomal enzyme, GAA, that causes Pompe disease. We engineered DYNE-401 by leveraging the FORCE platform to deliver GAA. We evaluated GAA delivery with our FORCE platform in vivo using hTfR1/6Neo mice, that were developed by crossing the well-established 6Neo mouse model of Pompe with mice expressing human transferrin receptor 1. Using this approach, intravenous administration cleared glycogen in muscle and the CNS and normalized lysosomal size in hTfR1/6Neo mice. This approach reduced serum neurofilament light chain, a biomarker of axonal injury, providing evidence of benefit in the CNS and displayed superior dose potency compared to GAA alone. Additional data with this approach supported the potential for monthly dosing, which is less frequent than approved enzyme replacement therapies for Pompe.

Previous wording

We were incorporated and commenced operations in 2017. Since our incorporation, we have devoted substantially all of our financial resources and efforts to organizing and staffing our company, business planning, raising capital, conducting research and development activities and filing and prosecuting patent applications. We do not have any products for sale and have not generated any revenue from product sales or otherwise. To date, we have principally raised capital through sales of equity securities and our initial borrowing under our Loan and Security Agreement, or the Loan Agreement, with Hercules Capital, Inc., or Hercules.

Current wording

We were incorporated and commenced operations in 2017. Since our incorporation, we have devoted substantially all of our financial resources and efforts to organizing and staffing our company, business planning, raising capital, conducting research and development activities and filing and prosecuting patent applications. We do not have any products for sale and have not generated any revenue from product sales or otherwise. To date, we have principally raised capital through sales of equity securities and our borrowing under our Loan and Security Agreement, or the Loan Agreement, with Hercules Capital, Inc., or Hercules.

Previous wording

Since our inception, we have incurred significant operating losses. Our ability to generate any product revenue or product revenue sufficient to achieve profitability will depend on the successful development and eventual commercialization of one or more product candidates. For the nine months ended September 30, 2025 and 2024, we reported net losses of $334.3 million and $227.9 million, respectively. As of September 30, 2025, we had an accumulated deficit of $1.3 billion.

Current wording

Since our inception, we have incurred significant operating losses. Our ability to generate any product revenue or product revenue sufficient to achieve profitability will depend on the successful development and eventual commercialization of one or more product candidates. For the three months ended March 31, 2026 and 2025, we reported net losses of $120.9 million and $115.4 million, respectively. As of March 31, 2026, we had an accumulated deficit of $1.5 billion.

Previous wording

advance our product candidates for DM1, DMD, FSHD and Pompe and conduct research programs in additional indications;

Current wording

advance our product candidates for DMD, DM1, FSHD and Pompe and conduct research programs in additional indications;

Previous wording

hire additional clinical, regulatory and scientific personnel;

Current wording

hire additional clinical, regulatory, scientific, medical affairs and commercial operations personnel;

Previous wording

establish manufacturing sources for any product candidate we may develop, including the Fab antibody, linkers and therapeutic payload that will comprise the product candidate, and secure supply chain capacity to provide sufficient quantities for preclinical and clinical development and commercial supply;

Current wording

establish manufacturing sources for any product candidate we may develop, including the Fab, linkers and therapeutic payload that will comprise the product candidate, and secure supply chain capacity to provide sufficient quantities for preclinical and clinical development and commercial supply;

Previous wording

ultimately establish a sales, marketing and distribution infrastructure to commercialize any products for which we may obtain marketing approval; and

Current wording

establish a sales, marketing and distribution infrastructure to commercialize any products for which we may obtain marketing approval; and

Previous wording

As a result, we will need substantial additional funding to support our continuing operations and pursue our growth strategy. Until such time as we can generate significant revenue from product sales, if ever, we expect to finance our operations through a combination of equity offerings, debt financings, collaborations, strategic alliances and licensing arrangements. We may be unable to raise additional funds or enter into such other agreements or arrangements when needed, on favorable terms, or at all. If we fail to raise capital or enter into such agreements or arrangements as and when needed, we may have to significantly delay, reduce or eliminate the development or future commercialization of one or more product candidates we may develop.

Current wording

As a result, we will need substantial additional funding to support our continuing operations and pursue our growth strategy. Until such time as we can generate significant revenue from product sales, if ever, we expect to finance our operations through a combination of equity offerings, debt financings, collaborations, strategic alliances and licensing arrangements, and terms loans under our Loan Agreement with Hercules. We may be unable to raise additional funds or enter into such other agreements or arrangements when needed, on favorable terms, or at all. If we fail to raise capital or enter into such agreements or arrangements as and when needed, we may have to significantly delay, reduce or eliminate the development or future commercialization of one or more product candidates we may develop.

Previous wording

We believe that our existing cash, cash equivalents and marketable securities will enable us to fund our operating expenses, debt service obligations and capital expenditure requirements into the third quarter of 2027. Based on our current plans and anticipated timelines and assuming positive data results from the Registrational Expansion Cohorts of our ACHIEVE and DELIVER clinical trials and assuming no additional testing is required by the FDA, we estimate that these cash resources would be sufficient to enable us to obtain data from the Registrational Expansion Cohorts of our ACHIEVE and DELIVER clinical trials, submit applications for marketing approval to the FDA for z-rostudirsen in DMD and z-basivarsen in DM1 using the Accelerated Approval pathway and obtain a decision from the FDA with respect to the application for marketing approval for z-rostudirsen and, if approved, commercially launch z-rostudirsen in the United States.

Current wording

We believe that our existing cash, cash equivalents and marketable securities will enable us to fund our operating expenses, debt service obligations and capital expenditure requirements into the first quarter of 2028.

Previous wording

We have based our estimates as to how long we expect we will be able to fund our operations, debt service obligations and capital expenditure requirements on assumptions that may prove to be wrong. We could use our available capital resources sooner than we currently expect, in which case we would be required to obtain additional financing, which may not be available to us on acceptable terms, or at all. Our failure to raise capital as and when needed would have a negative impact on our financial condition and our ability to pursue our business strategy. See “—Liquidity and capital resources” below. These estimates do not give effect to any additional funding tranches we may obtain access to under our Loan Agreement with Hercules, subject to the achievement of specified clinical, regulatory and commercial milestones, and do not give effect to any revenue we may generate on commercial sales of any products for which we obtain regulatory approval.

Current wording

We have based our estimate as to how long we expect we will be able to fund our operations, debt service obligations and capital expenditure requirements on assumptions that may prove to be wrong. We could use our available capital resources sooner than we currently expect, in which case we would be required to obtain additional financing, which may not be available to us on acceptable terms, or at all. Our failure to raise capital as and when needed would have a negative impact on our financial condition and our ability to pursue our business strategy. See “—Liquidity and capital resources” below. These estimates do not give effect to any additional funding tranches we may obtain access to under our Loan Agreement with Hercules, subject to the achievement of specified clinical, regulatory and commercial milestones, and do not give effect to any revenue we may generate on commercial sales of any products for which we obtain regulatory approval.

Previous wording

The new U.S. administration has announced or imposed a series of tariffs on U.S. trading partners. In response, several countries have threatened or imposed retaliatory measures. While we have not experienced, and do not currently expect to experience, any significant direct impact from these tariffs and retaliatory measures, the full extent of the future impact of these and other threatened measures remains uncertain. We continue to monitor these tariffs and retaliatory measures and their possible effects on our business.

Current wording

The U.S. administration has announced or imposed multiple series of tariffs on U.S. trading partners, and there is uncertainty as to whether, when, or to what extent they may apply to our supply chain. In response, several countries have threatened or imposed retaliatory measures, and multiple states have challenged these tariffs in court. While we have not experienced, and do not currently expect to experience, any significant direct impact from these tariffs or retaliatory measures, we could experience a negative impact on our costs of materials and production processes and supply chain disruptions, and the uncertainty surrounding the future of U.S. trade policy may itself negatively impact our supply chain operations and the costs of materials and production processes. Supply chain disruptions may impact the development, testing and clinical trials of our product candidates, and regulatory approval or commercial launch of any resulting product may be delayed or not obtained, which could significantly harm our business. The full extent of the future impact of these and other threatened measures remains uncertain. We continue to monitor these tariffs, retaliatory measures, and related litigation, and their possible effects on our business. See Part II, Item 1A. “Risk Factors—Risks related to regulatory approval and other regulatory and legal compliance matters” in this Quarterly Report for additional risks associated with current U.S. trade policy.

Previous wording

the cost of laboratory supplies and acquiring, developing and manufacturing materials for use in our research, preclinical studies and clinical trials, including those incurred under agreements with third parties, such as consultants and CMOs;

Current wording

the cost of laboratory supplies and acquiring, developing and manufacturing materials for use in our research, preclinical studies and clinical trials, including those incurred under agreements with third parties, such as consultants and contract manufacturing organizations, or CMOs;

Previous wording

Product candidates in later stages of clinical development generally have higher development costs than those in earlier stages of clinical development, primarily due to the increased size and duration of later-stage clinical trials. Accordingly, we expect that our research and development expenses will increase substantially as we advance z-basivarsen and z-rostudirsen through clinical trials, in connection with our preclinical and clinical development activities of DYNE-302, our FSHD product candidate, and DYNE-401, our Pompe disease product candidate, and if, and as, we advance any other product candidates through preclinical studies and clinical trials. At this time, we cannot accurately estimate or know the nature, timing and costs of the efforts that will be necessary to complete the preclinical and clinical development of any product candidates we may develop. The successful development of any product candidate is highly uncertain. This is due to the numerous risks and uncertainties associated with product development, including the following:

Current wording

Product candidates in later stages of clinical development generally have higher development costs than those in earlier stages of clinical development, primarily due to the increased size and duration of later-stage clinical trials. Accordingly, we expect that our research and development expenses will increase substantially as we advance z-rostudirsen and z-basivarsen through clinical trials, in connection with our preclinical and clinical development activities of DYNE-302, our FSHD product candidate, and DYNE-401, our Pompe disease product candidate, and if, and as, we advance any other product candidates through preclinical studies and clinical trials.

Previous wording

General and administrative expenses consist primarily of employee-related expenses, including salaries, related benefits and stock-based compensation, for employees in executive, finance, corporate and business development and administrative functions. General and administrative expenses also include legal fees relating to patent and corporate matters; professional fees for accounting, auditing, tax and administrative consulting services; insurance costs; administrative travel expenses; and facility-related expenses, which include allocated expenses for rent, depreciation and maintenance of facilities and other operating costs.

Current wording

General and administrative expenses consist primarily of employee-related expenses, including salaries, related benefits and stock-based compensation, for employees in executive, finance, corporate and business development, commercial and administrative functions. General and administrative expenses also include legal fees relating to patent and corporate matters; professional fees for accounting, auditing, tax and administrative consulting services; insurance costs; administrative travel expenses; commercial readiness activities; and facility-related expenses, which include allocated expenses for rent, depreciation and maintenance of facilities and other operating costs.

Previous wording

Expenses related to z-basivarsen increased in the three months ended September 30, 2025 compared to the three months ended September 30, 2024. This was attributable to higher manufacturing activity in the three months ended September 30, 2025 to produce a sufficient clinical supply of drug product for the ongoing ACHIEVE trial and an increase in clinical trial activity primarily for the registrational expansion cohort of the ACHIEVE trial. Expenses related to z-rostudirsen decreased in the three months ended September 30, 2025 compared to the three months ended September 30, 2024. This was attributable to lower manufacturing cost in the three months ended September 30, 2025 due to the timing of a new raw material purchase in the three months ended September 30, 2024.

Current wording

Expenses related to z-rostudirsen increased in the three months ended March 31, 2026 compared to the three months ended March 31, 2025. This was attributable to higher manufacturing activity in the first quarter of 2026 for drug substance conjugation primarily for clinical supply for the long-term extension of the DELIVER trial and the anticipated commencement of the global confirmatory Phase 3 clinical trial of z-rostudirsen in the second quarter of 2026. Additionally, higher clinical costs were incurred in the first quarter of 2026 due to z-rostudirsen Phase 3 start-up costs. Expenses related to z-basivarsen decreased in the three months ended March 31, 2026 compared to the three months ended March 31, 2025. This was primarily attributable to higher manufacturing activity in the first quarter of 2025 for process performance qualification batches of oligonucleotide payload and the timing of drug substance conjugation activities, partially offset by higher clinical trial costs due to the ongoing enrollment of the registrational expansion cohort of the ACHIEVE trial and the commencement of the HARMONIA trial in March 2026.

Previous wording

The increase in platform and external research and development expenses in the nine months ended September 30, 2025 compared to the nine months ended September 30, 2024 was primarily due to increased external research activity associated with our preclinical programs and product candidates. The increase in personnel-related expenses was primarily due to increased headcount in our research and development function. The increase in facility-related and other expenses was primarily due to the increased costs of supporting a larger number of research and development personnel.

Current wording

The increase in platform and external research and development expenses in the three months ended March 31, 2026 compared to the three months ended March 31, 2025 was due to increased external research activity associated with our preclinical programs and product candidates, primarily DYNE-302 and DYNE-401. The increase in personnel-related expenses was primarily due to increased headcount in our research and development function of 37 employees and higher stock-based compensation expense for awards granted to new hires and existing employees. The increase in facility-related and other expenses was primarily due to the increased costs of supporting a larger number of research and development personnel.

Previous wording

The increase in personnel-related and stock-based compensation expenses in the three months ended September 30, 2025 compared to the three months ended September 30, 2024 was due to increased headcount in our general and administrative function. Professional and consulting fees increased due to the higher consulting costs to support the growth of the organization in the three months ended September 30, 2025. Facility-related and other expenses increased due to higher costs of supporting a larger number of general and administrative personnel in the three months ended September 30, 2025.

Current wording

The increase in personnel-related and stock-based compensation expenses in the three months ended March 31, 2026 compared to the three months ended March 31, 2025 was due to increased headcount in our general and administrative function of 34 employees. Professional and consulting fees increased due to the higher consulting costs for preparation activities for the potential launch of z-rostudirsen and the overall growth of the organization in the three months ended March 31, 2026. Facility-related and other expenses increased due to higher costs of supporting a larger number of general and administrative personnel in the three months ended March 31, 2026.

Previous wording

Interest income for the nine months ended September 30, 2025 and 2024 was $22.2 million and $19.3 million, respectively, due to interest earned on invested cash balances. The increase in interest income was due to an increased cash, cash equivalents and marketable securities balance throughout the nine months ended September 30, 2025 compared to the nine months ended September 30, 2024.

Current wording

Interest income for the three months ended March 31, 2026 and 2025 was $8.8 million and $7.1 million, respectively, due to interest earned on invested cash balances. The increase in interest income was due to increased cash, cash equivalents and marketable securities balances in the three months ended March 31, 2026 compared to the three months ended March 31, 2025.

Previous wording

Interest expense for the three months ended September 30, 2025 was $2.9 million due to our entry into the Loan Agreement with Hercules in June 2025. No interest expense was incurred in the three months ended September 30, 2024.

Current wording

Interest expense for the three months ended March 31, 2026 was $4.2 million due to our entry into the Loan Agreement with Hercules in June 2025. No interest expense was incurred in the three months ended March 31, 2025.

Previous wording

Other income for the three months ended September 30, 2025 was $0.3 million while other expense for the three months ended September 30, 2024 was $0.7 million due to realized foreign currency gains.

Current wording

Other income for the three months ended March 31, 2026 and 2025 was $0.1 million in each quarter due to realized foreign currency gains.

Previous wording

Since our inception, we have incurred significant operating losses. We expect to incur significant expenses and operating losses for the foreseeable future as we support our continued research activities and development of our product candidates and platform. We have not yet commercialized any product candidates, and we do not expect to generate revenue from sales of any product candidates at least until 2027, if at all. To date, we have funded our operations primarily with proceeds from sales of equity securities and our initial borrowing under the Loan Agreement with Hercules. As of September 30, 2025 we had cash, cash equivalents and marketable securities of $791.9 million.

Current wording

Since our inception, we have incurred significant operating losses. We expect to incur significant expenses and operating losses for the foreseeable future as we support our continued research activities and development of our product candidates and platform. We have not yet commercialized any product candidates, and we do not expect to generate revenue from sales of any product candidates at least until 2027, if at all. To date, we have funded our operations primarily with proceeds from sales of equity securities and our borrowing under the Loan Agreement with Hercules. As of March 31, 2026 we had cash, cash equivalents and marketable securities of $972.2 million.

Previous wording

In November 2021, we filed a universal shelf registration statement on Form S-3, or the 2021 Shelf Registration Statement, to register for sale from time to time up to $400.0 million of common stock, preferred stock, debt securities, warrants and/or units in one or more offerings. Further, in November 2021, we entered into an Open Market Sale Agreement SM, or the Sales Agreement, with Jefferies LLC, or Jefferies, and included in the 2021 Shelf Registration Statement a prospectus relating to the Sales Agreement, pursuant to which, from time to time, we may offer and sell shares of our common stock having an aggregate offering price of up to $150.0 million, which we refer to as our at-the-market offering program. Sales of common stock under the Sales Agreement through Jefferies may be made by any method that is deemed an “at-the-market” offering as defined in Rule 415(a)(4) under the Securities Act of 1933, as amended, or Securities Act. On January 4, 2024, we notified Jefferies that we were suspending and terminating the prospectus filed under our 2021 Shelf Registration Statement relating to the Sales Agreement for our at-the-market offering program.

Current wording

In November 2021, we entered into an Open Market Sale Agreement SM, or the Sales Agreement, with Jefferies LLC, or Jefferies. On March 5, 2024, we filed a universal shelf registration statement on Form S-3, or the 2024 Shelf Registration Statement, and included a prospectus relating to the Sales Agreement. Under the 2024 Shelf Registration Statement, we may offer and sell debt securities, common stock, preferred stock, units and/or warrants from time to time at an indeterminate aggregate offering price in one or more offerings. In November 2024, we filed a prospectus supplement relating to the Sales Agreement, pursuant to which, in accordance with the Sales Agreement, we may offer and sell shares of our common stock having an aggregate offering price of up to $300.0 million, which we refer to as our at-the-market offering program. Sales of common stock under the Sales Agreement through Jefferies may be made by any method that is deemed an “at-the-market” offering as defined in Rule 415(a)(4) under the Securities Act. During the three months ended March 31, 2026, we did not issue or sell any shares of common stock pursuant to the Sales Agreement.

Previous wording

In June 2025, we entered into the Loan Agreement with Hercules, in its capacity as administrative agent and collateral agent and as a lender, and certain other financial institutions that from time to time become parties to the Loan Agreement as lenders, which we refer to collectively as the Lenders. The Loan Agreement provides for term loans in an aggregate principal amount of up to $275.0 million under multiple tranches, available as follows: (i) an initial term loan tranche funded on the closing date of the Loan Agreement in aggregate principal amount of $100.0 million; (ii) subject to the achievement of specified clinical, regulatory and commercial milestones, three additional term loan tranches totaling up to $115.0 million; and (iii) subject to approval by the Lenders’ investment committee in their discretion, a final term loan tranche of up to $60.0 million. On June 27, 2025, we received net proceeds of $98.8 million from the initial term loan tranche, after deducting debt issuance costs payable by us. Refer to Note 7, “Long-Term Debt” in the accompanying notes to the condensed consolidated financial statements for a discussion of the Loan Agreement with Hercules.

Current wording

In June 2025, we entered into the Loan Agreement with Hercules, in its capacity as administrative agent and collateral agent and as a lender, and certain other financial institutions that from time to time become parties to the Loan Agreement as lenders, which we refer to collectively as the Lenders. In December 2025, we entered into the First Amendment to the Loan Agreement with Hercules. The Loan Agreement, as amended by the First Amendment, provides for term loans in an aggregate principal amount of up to $275.0 million under multiple tranches, available as follows: (i) an initial term loan tranche funded on the closing date of the Loan Agreement in aggregate principal amount of $100.0 million; (ii) subject to the achievement of specified clinical, regulatory and commercial milestones, and after the borrowing of the second term loan tranche of $50.0 million in December 2025, two additional term loan tranches totaling up to $75.0 million; and (iii) subject to approval by the Lenders’ investment committee in their discretion, a final term loan tranche of up to $50.0 million. At March 31, 2026, the principal term loan balance was $150.0 million. Refer to Note 7, “Debt” in the accompanying notes to the condensed consolidated financial statements for a discussion of the Loan Agreement with Hercules.

Previous wording

During the nine months ended September 30, 2025, operating activities used $291.4 million of cash, due to our net loss of $334.3 million, partially offset by non-cash charges of $35.0 million and changes in our operating assets and liabilities of $7.9 million. Net cash provided by changes in our operating assets and liabilities primarily consisted of a $17.7 million increase in accounts payable and other liabilities and a $3.2 million decrease in prepaid expenses and other current assets, partially offset by a $13.0 million increase in other non-current assets. During the nine months ended September 30, 2024, operating activities used $208.0 million of cash, due to our net loss of $227.9 million and net cash used by changes in our operating assets and liabilities of $14.4 million, partially offset by non-cash charges of $34.2 million. Net cash used by changes in our operating assets and liabilities primarily consisted of a $8.0 million decrease in accounts payable and other liabilities and a $6.4 million increase in prepaid expenses and other current assets. Changes in our operating assets and liabilities during these periods were generally due to the growth of our business, increased clinical trial activity, increased manufacturing activities, advancement of our product candidates, the timing of vendor invoices and payments and annual bonus payments.

Current wording

During the three months ended March 31, 2026, operating activities used $144.9 million of cash, due to our net loss of $120.9 million and net cash used by changes in our operating assets and liabilities of $37.6 million, partially offset by non-cash charges of $13.6 million. Net cash used in changes in our operating assets and liabilities primarily consisted of a $32.8 million increase in prepaid expenses and other current assets and a $4.8 million decrease in accounts payable and other liabilities. During the three months ended March 31, 2025, operating activities used $105.9 million of cash, due to our net loss of $115.4 million and net cash used by changes in our operating assets and liabilities of $3.6 million, partially offset by non-cash charges of $13.1 million. Net cash used by changes in our operating assets and liabilities primarily consisted of a $8.6 million decrease in accounts payable and other liabilities and a $5.0 million decrease in prepaid expenses and other current assets. Changes in our operating assets and liabilities during these periods were generally due to the growth of our business, increased clinical trial activity, increased manufacturing activities, advancement of our product candidates, the timing of vendor invoices and payments and annual bonus payments.

Previous wording

During the nine months ended September 30, 2025, net cash used in investing activities was $29.7 million due to purchases of marketable securities of $153.8 million, an advance payment for long-lead equipment for $18.8 million, and purchases of property and equipment of $1.4 million, partially offset by maturities of marketable securities of $135.8 million and sales of marketable securities of $8.5 million. During the nine months ended September 30, 2024, net cash used in investing activities was $188.1 million due to purchases of marketable securities of $264.7 million and purchases of property and equipment of $1.3 million, partially offset by maturities of marketable securities of $76.2 million and sales of marketable securities of $1.7 million.

Current wording

During the three months ended March 31, 2026, net cash used in investing activities was $2.4 million due to purchases of marketable securities of $64.3 million and purchases of property and equipment of $0.2 million, partially offset by maturities of marketable securities of $33.5 million and sales of marketable securities of $28.6 million. During the three months ended March 31, 2025, net cash provided by investing activities was $1.5 million due to maturities of marketable securities of $65.4 million and sales of marketable securities of $3.0 million, partially offset by purchases of marketable securities of $66.0 million and purchases of property and equipment of $1.0 million.

Previous wording

During the nine months ended September 30, 2025, net cash provided by financing activities was $459.3 million, consisting of $215.8 million in aggregate net proceeds from sales of common stock under our follow-on offering in July 2025, $140.6 million in aggregate net proceeds from sales of common stock under our at-the-market offering program, $98.8 million in net proceeds from the initial term loan tranche under the Loan Agreement with Hercules and $4.6 million in proceeds received from stock option exercises. These cash inflows are partially offset by $0.5 million in payment of debt issuance costs. During the nine months ended September 30, 2024, net cash provided by financing activities was $806.3 million, consisting of $675.2 million in aggregate net proceeds from sales in our public offerings in January 2024 and May 2024, $97.9 million in aggregate net proceeds from sales of our common stock under our at-the-market offering program and $33.2 million in net proceeds received from stock option exercises.

Current wording

During the three months ended March 31, 2026, net cash provided by financing activities was $7.1 million, including $6.8 million in proceeds from our vendor financing arrangement that we entered into during the quarter and $1.3 million in proceeds received from stock option exercises. These cash inflows were partially offset by $0.6 million in repayments related to our vendor financing arrangement and the payment of $0.4 million of issuance costs from the follow-on public offering we completed in December 2025, pursuant to which we issued and sold 21,827,549 shares of our common stock and from which we received net proceeds of $377.7 million, after deducting underwriting discounts and commissions and offering expenses paid by us. During the three months ended March 31, 2025, net cash provided by financing activities was $141.2 million, consisting of $140.6 million in aggregate net proceeds from sales of our common stock under our at-the-market offering program and $0.6 million in net proceeds received from stock option exercises.

Previous wording

We expect our expenses to increase in connection with our ongoing activities, particularly as we advance the clinical development of z-basivarsen and z-rostudirsen, the development of our FSHD and Pompe programs and additional research programs. The timing and amount of our operating expenditures will depend largely on:

Current wording

We expect our expenses to increase in connection with our ongoing activities, particularly as we advance the clinical development of z-rostudirsen and z-basivarsen, the development of our FSHD, Pompe and DMD franchise programs and additional research programs. The timing and amount of our operating expenditures will depend largely on:

Previous wording

the costs and timing of future commercialization activities, including product manufacturing, marketing, sales and distribution, for any product candidate we may develop for which we obtain marketing approval;

Current wording

the costs and timing of future commercialization activities and related preparations, including product manufacturing, marketing, sales and distribution, for any product candidate we may develop for which we obtain marketing approval;

Previous wording

We believe that our existing cash, cash equivalents and marketable securities will enable us to fund our operating expenses, debt service obligations and capital expenditure requirements into the third quarter of 2027. Based on our current plans and anticipated timelines and assuming positive data results from the registrational expansion cohorts of our ACHIEVE and DELIVER clinical trials and assuming no additional testing is required by the FDA, we estimate that these cash resources would be sufficient to enable us to obtain data from the registrational expansion cohorts of our ACHIEVE and DELIVER clinical trials, submit applications for marketing approval to the FDA for z-rostudirsen in DMD and z-basivarsen in DM1 using the Accelerated Approval pathway and obtain a decision from the FDA with respect to the application for marketing approval for z-rostudirsen and, if approved, commercially launch z-rostudirsen in the United States. We have based these estimates on assumptions that may prove to be wrong, and we could exhaust our available capital resources sooner than we expect.

Current wording

We believe that our existing cash, cash equivalents and marketable securities will enable us to fund our operating expenses, debt service obligations, and capital expenditure requirements into the first quarter of 2028. We have based this estimate on assumptions that may prove to be wrong, and we could exhaust our available capital resources sooner than we expect.

Previous wording

Until such time, if ever, as we can generate substantial product revenue, we expect to finance our cash needs through a combination of equity offerings, debt financings, collaborations, strategic alliances, and marketing, distribution or licensing arrangements with third parties. To the extent that we raise additional capital through the sale of equity or convertible debt securities, the ownership interest of our stockholders may be materially diluted, and the terms of such securities could include liquidation or other preferences that adversely affect the rights of holders of our common stock. Debt financing and preferred equity financing, if available, may involve agreements that include restrictive covenants that limit our ability to take specified actions, such as incurring additional debt, making capital expenditures or declaring dividends. If we raise funds through collaborations, strategic alliances or marketing, distribution or licensing arrangements with third parties, we may have to relinquish valuable rights to our technologies, future revenue streams, research programs or product candidates or grant licenses on terms that may not be favorable to us. We may be unable to raise additional funds or enter into such other agreements or arrangements when needed, on favorable terms, or at all. If we fail to raise capital or enter into such agreements other arrangements as and when needed, we may have to significantly delay, reduce or eliminate the development or future commercialization of one or more of our product candidates we may develop. See Item 1A. “Risk factors” in this Quarterly Report for additional risks associated with our substantial capital requirements.

Current wording

Until such time, if ever, as we can generate substantial product revenue, we expect to finance our cash needs through a combination of equity offerings, debt financings, collaborations, strategic alliances, and marketing, distribution or licensing arrangements with third parties. To the extent that we raise additional capital through the sale of equity or convertible debt securities, the ownership interest of our stockholders may be materially diluted, and the terms of such securities could include liquidation or other preferences that adversely affect the rights of holders of our common stock. Debt financing and preferred equity financing, if available, may involve agreements that include restrictive covenants that limit our ability to take specified actions, such as incurring additional debt, making capital expenditures or declaring dividends. If we raise funds through collaborations, strategic alliances or marketing, distribution or licensing arrangements with third parties, we may have to relinquish valuable rights to our technologies, future revenue streams, research programs or product candidates or grant licenses on terms that may not be favorable to us. We may be unable to raise additional funds or enter into such other agreements or arrangements when needed, on favorable terms, or at all. If we fail to raise capital or enter into such agreements or arrangements as and when needed, we may have to significantly delay, reduce or eliminate the development or future commercialization of one or more of our product candidates we may develop. See Part II, Item 1A. “Risk Factors” in this Quarterly Report for additional risks associated with our substantial capital requirements.

Previous wording

We enter into contracts in the normal course of business with CROs, CMOs and other third parties for preclinical research studies, clinical trials and testing and manufacturing services. These contracts typically do not contain minimum purchase commitments and are generally cancelable by us upon written notice. Payments due upon cancellation consist of payments for services provided or expenses incurred, including noncancelable obligations of our service providers, up to the date of cancellation and in the case of certain arrangements with CROs and CMOs may include non-cancelable fees.

Current wording

We enter into contracts in the normal course of business with CROs, CMOs and other third parties for preclinical research studies, clinical trials and testing and manufacturing services. Except for the master manufacturing services agreements described below, these contracts typically do not contain significant minimum purchase commitments and are generally cancelable by us upon written notice. Payments due upon cancellation consist of payments for services provided or expenses incurred, including noncancelable obligations of our service providers, up to the date of cancellation and in the case of certain arrangements with CROs and CMOs may include non-cancelable fees.

Previous wording

We have also entered into a license agreement with the University of Mons under which we are obligated to make specified milestone and royalty payments. The payment obligations under this agreement are contingent upon future events, such as our achievement of specified development, regulatory and commercial milestones, or generating product sales. We are unable to estimate the timing or likelihood of achieving these milestones or generating future product sales.

Current wording

We have also entered into a license agreement with the University of Mons under which we are obligated to make specified milestone and royalty payments. The payment obligations under this agreement are contingent upon future events, such as our achievement of specified development, regulatory and commercial milestones, or generating product sales. We are unable to estimate the timing or likelihood of achieving these milestones or generating future product sales. For additional information about our license agreement with the University of Mons and amounts that could become payable in the future under that agreement, see Item 1. "Business—Intellectual Property—License Agreement with the University of Mons" in the Annual Report on Form 10-K filed with the SEC on March 2, 2026.

Previous wording

On January 15, 2025, we entered into a master manufacturing services agreement with a CMO which secures capacity at the CMO's manufacturing facilities for certain of our product candidates and components thereof. As of September 30, 2025, we have paid $31.2 million towards non-current assets under this agreement and pursuant to a mutually agreed rolling forecast we have committed to pay an additional $65.6 million in fees through September 2027. In specified termination circumstances, the agreement requires us to pay the CMO for services completed, the cost of the CMO's raw materials that cannot be repurposed and specified cancellation fees. This agreement formalizes and supersedes a letter agreement that we entered into with the CMO on July 18, 2024.

Current wording

On January 15, 2025, we entered into a master manufacturing services agreement with a CMO which secures capacity at the CMO's manufacturing facilities for certain of our product candidates and components thereof. As of March 31, 2026, we have paid $27.7 million towards current assets and $31.2 million towards non-current assets under this agreement and pursuant to a mutually agreed rolling forecast we have committed to pay an additional $107.6 million in fees through March 2028. In specified termination circumstances, the agreement requires us to pay the CMO for services completed, the cost of the CMO's raw materials that cannot be repurposed and specified cancellation fees. This agreement formalizes and supersedes a letter agreement that we entered into with the CMO on July 18, 2024.

Previous wording

On October 31, 2025, we entered into another master manufacturing services agreement with a CMO which also secures capacity at the CMO's manufacturing facilities for certain of our product candidate components. The agreement obligates us to compensate the CMO for producing certain of our product candidate components pursuant to a mutually agreed rolling forecast. Upon execution, we committed to compensate the CMO at least $25.5 million in fees thorugh March 2027. In specified termination circumstances, the agreement requires us to pay the CMO for services completed, the cost of the CMO's raw materials that cannot be repurposed, capital equipment and certain manufacturing activities previously committed to.

Current wording

On October 31, 2025, we entered into another master manufacturing services agreement with a CMO which also secures capacity at the CMO's manufacturing facilities for certain of our product candidate components. The agreement obligates us to compensate the CMO for producing certain of our product candidate components pursuant to a mutually agreed rolling forecast, pursuant to which, as of March 31, 2026, we have committed to pay an additional $52.7 million in fees through September 2027. In specified termination circumstances, the agreement requires us to pay the CMO for services completed, the cost of the CMO's raw materials that cannot be repurposed, capital equipment and certain manufacturing activities previously committed to.

Previous wording

We define our critical accounting policies as those accounting principles generally accepted in the United States of America that require us to make subjective estimates and judgments about matters that are uncertain and are likely to have a material impact on our financial condition and results of operations as well as the specific manner in which we apply those principles. Management has determined that our most critical accounting policies are those relating to accrued research and development expenses and stock-based compensation and that these policies have the most significant level of estimation uncertainty and have and are reasonably likely to have a material impact on our financial condition and results of operations. As we advance our product candidates into and through clinical development, we expect research and development expenses and, in particular, our accounting for accrued research and development expenses to be an increasingly important critical accounting policy.

Current wording

We define our critical accounting policies as those accounting principles generally accepted in the United States of America that require us to make subjective estimates and judgments about matters that are uncertain and are likely to have a material impact on our financial condition and results of operations as well as the specific manner in which we apply those principles. Management has determined that our most critical accounting policies are those relating to accrued research and development expenses and stock-based compensation. As we advance our product candidates into and through clinical development, we expect research and development expenses and, in particular, our accounting for accrued research and development expenses to be an increasingly important critical accounting policy.