What changed in Design Therapeutics, Inc.'s 2025 10-K compared to 2024?

Across the narrative sections we track, Design Therapeutics, Inc. (DSGN) added 193 paragraphs, removed 184, and edited 156 between the 2024 and 2025 10-K filings. The biggest movers are Item 1C. Cybersecurity (+193/−184).

Did Design Therapeutics, Inc. update its Cybersecurity disclosure (Item 1C) in 2025?

Item 1C Cybersecurity has 193 paragraph-level changes between the 2024 and 2025 filings.

Where does this DSGN 10-K diff come from?

The source filings are Design Therapeutics, Inc.'s official 2024 and 2025 Form 10-K annual reports from SEC EDGAR. 10q10k.net parses each filing, aligns paragraphs by section (Item 1, 1A, 1C, 2, 3, 7, 7A), and highlights every added, removed and edited sentence side-by-side.

What changed in Design Therapeutics, Inc.'s 10-K — 2024 vs 2025

Paragraph-level year-over-year comparison of Design Therapeutics, Inc.'s 2024 and 2025 10-K annual filings, covering the Business, Risk Factors, Legal Proceedings, Cybersecurity, MD&A and Market Risk sections. Every new, removed and edited paragraph is highlighted side-by-side so you can see exactly what management changed in the 2025 report.

+193 added−184 removedSource: 10-K (2026-03-09) vs 10-K (2025-03-10)

Top changes in Design Therapeutics, Inc.'s 2025 10-K

193 paragraphs added · 184 removed · 156 edited across 1 sections

Item 1C. Cybersecurity+193 / −184 · 156 edited

Item 1C. Cybersecurity

Cybersecurity — threats and controls disclosure

156 edited+37 added−28 removed163 unchanged

2024 filing

2025 filing

Biggest changeDue to the existence of the valuation allowance, limitations created by future ownership changes, if any, will not impact the Company’s effective tax rate. 141 Significant components of the Company's net deferred tax assets at December 31, 2024 and 2023 were as follows (in thousands): December 31, 2024 December 31, 2023 Deferred tax assets: Net operating losses $ 18,885 $ 15,074 Capitalized research costs 20,545 16,635 Research and development credits 9,352 6,996 Lease liability 492 641 Stock-based compensation 3,908 3,255 Other 797 810 Total gross deferred tax assets 53,979 43,411 Valuation allowance ( 53,143 ) ( 42,436 ) Total deferred tax assets 836 975 Deferred tax liabilities: Right of use asset ( 467 ) ( 618 ) Other ( 369 ) ( 357 ) Total deferred tax liabilities ( 836 ) ( 975 ) Net deferred tax assets $ — $ — A reconciliation of the Company's income tax expense (benefit) to the amount computed by applying the federal statutory income tax rate for the periods presented were as follows (in thousands): December 31, 2024 December 31, 2023 Expected tax benefit at federal statutory rate $ ( 10,413 ) $ ( 14,042 ) State income taxes, net of federal benefit ( 34 ) ( 37 ) Research and development credits ( 2,354 ) ( 3,722 ) Stock-based compensation 1,310 906 162(m) officer's compensation 799 383 Other ( 102 ) 132 Change in valuation allowance 10,794 16,380 Provision for income taxes $ — $ — The Company recognizes a tax benefit from an uncertain tax position when it is more likely than not that the position will be sustained upon examination by tax authorities.

Biggest changeSignificant components of the Company's net deferred tax assets at December 31, 2025 and 2024 were as follows (in thousands): December 31, 2025 December 31, 2024 Deferred tax assets: Net operating losses $ 31,412 $ 18,885 Capitalized research costs 19,621 20,545 Research and development credits 11,678 9,352 Lease liability 326 492 Stock-based compensation 3,810 3,908 Other 1,026 797 Total gross deferred tax assets 67,873 53,979 Valuation allowance ( 67,327 ) ( 53,143 ) Total deferred tax assets 546 836 Deferred tax liabilities: Right of use asset ( 305 ) ( 467 ) Other ( 241 ) ( 369 ) Total deferred tax liabilities ( 546 ) ( 836 ) Net deferred tax assets $ — $ — A reconciliation of the Company's income tax expense (benefit) to the amount computed by applying the federal statutory income tax rate for the periods presented were as follows (in thousands): Year ended December 31, 2025 2024 Income taxes (benefit) at statutory rate: $ ( 14,656 ) 21.00 % $ ( 10,413 ) 21.00 % State and local income taxes, net of federal benefit:* ( 181 ) 0.26 % ( 141 ) 0.28 % Tax credits: Research and development credits ( 1,997 ) 2.86 % ( 2,104 ) 4.24 % Change in valuation allowance: 13,271 ( 19.02 ) % 10,159 ( 20.49 ) % Nontaxable or nondeductible items: Officer's compensation 1,721 ( 2.47 ) % 799 ( 1.61 ) % Stock-based compensation 1,381 ( 1.98 ) % 1,310 ( 2.64 ) % Other 25 ( 0.04 ) % ( 29 ) 0.06 % Changes in Unrecognized Tax Benefits: 474 ( 0.68 ) % 452 ( 0.91 ) % Other, net ( 38 ) 0.07 % ( 33 ) 0.07 % $ — 0.00 % $ — 0.00 % * State taxes in California comprise the majority (greater than 50 percent) of the tax effect in this category.

Our future research and development expenses may vary significantly based on a wide variety of factors such as: 116 • the number and scope, rate of progress, expense and results of our discovery, nonclinical and clinical development activities; • the number of trials required for approval; • the number of sites included in the trials; • the countries in which the trials are conducted; • the length of time required to enroll eligible patients; • the number of patients that participate in the trials; • the number of doses that patients receive; • the drop-out or discontinuation rates of patients; • potential additional safety monitoring requested by regulatory agencies; • the scope and costs of designing and implementing drug product improvements (including alternate formulations) and manufacturing our product candidates; • the duration of patient participation in the trials and follow-up; • the phase of development of the product candidate; • the efficacy and safety profile of the product candidate; • the timing, receipt, and terms of any approvals from applicable regulatory authorities including FDA and non-U.S. regulators; • maintaining a continued acceptable safety profile of our product candidates following approval, if any, of our product candidates; • establishing clinical or commercial manufacturing capabilities or making arrangements with third-party manufacturers in order to ensure that we or our third-party manufacturers are able to make product successfully; • significant and changing government regulation and regulatory guidance; • the impact of any business interruptions to our operations or to those of the third parties with whom we work; and • the extent to which we establish additional strategic collaborations or other arrangements.

Our future research and development expenses may vary significantly based on a wide variety of factors such as: • the number and scope, rate of progress, expense and results of our discovery, nonclinical and clinical development activities; • the number of trials required for approval; • the number of sites included in the trials; • the countries in which the trials are conducted; • the length of time required to enroll eligible patients; • the number of patients that participate in the trials; • the number of doses that patients receive; • the drop-out or discontinuation rates of patients; • potential additional safety monitoring requested by regulatory agencies; • the scope and costs of designing and implementing drug product improvements (including alternate formulations) and manufacturing our product candidates; • the duration of patient participation in the trials and follow-up; • the phase of development of the product candidate; • the efficacy and safety profile of the product candidate; • the timing, receipt, and terms of any approvals from applicable regulatory authorities including FDA and non-U.S. regulators; • maintaining a continued acceptable safety profile of our product candidates following approval, if any, of our product candidates; • establishing clinical or commercial manufacturing capabilities or making arrangements with third-party manufacturers in order to ensure that we or our third-party manufacturers are able to make product successfully; • significant and changing government regulation and regulatory guidance; 121 • the impact of any business interruptions to our operations or to those of the third parties with whom we work; and • the extent to which we establish additional strategic collaborations or other arrangements.

In addition, the number of shares of common stock available for issuance under the ESPP will automatically increase on January 1 of each calendar year through January 1, 2031 in an amount equal to the lesser of (i) 1% of the total number of shares outstanding of the Company’s common stock on the last day of the calendar month before the date of each automatic increase and (ii) 1,200,000 shares; provided that before the date of any such increase, the Company’s board of directors may determine that such increase will be less than the amount set forth in clauses (i) and (ii).

In addition, the number of shares of common stock available for issuance under the ESPP automatically increases on January 1 of each calendar year through January 1, 2031 in an amount equal to the lesser of (i) 1% of the total number of shares outstanding of the Company’s common stock on the last day of the calendar month before the date of each automatic increase and (ii) 1,200,000 shares; provided that before the date of any such increase, the Company’s board of directors may determine that such increase will be less than the amount set forth in clauses (i) and (ii).

For example, cybersecurity risk is addressed as a component of our enterprise risk management program; our Chief Operating Officer and General Counsel work with management to prioritize our risk management processes and mitigate cybersecurity threats that are expected to be more likely to lead to a material impact to our business; our Chief Operating Officer and General Counsel evaluate material risks from cybersecurity threats against our overall business objectives and our Chief Operating Officer reports to the audit committee of the board of directors, which evaluates our overall enterprise risk.

For example, cybersecurity risk is addressed as a component of our enterprise risk management program; our Chief Operating Officer and General Counsel work with management to prioritize our risk management processes and mitigate cybersecurity threats that are expected to be more likely to lead to a material impact to our business; our Chief Operating Officer and General Counsel evaluate material risks from 114 cybersecurity threats against our overall business objectives and our Chief Operating Officer reports to the audit committee of the board of directors, which evaluates our overall enterprise risk.

Level 3: Unobservable inputs in which there is little or no market data, which require the reporting entity to develop its own assumptions. The carrying value of the Company’s cash, accounts payable and accrued liabilities are considered to be representative of their respective fair values due to the short-term nature of those instruments.

Level 3: Unobservable inputs in which there is little or no market data, which require the reporting entity to develop its own assumptions. 138 The carrying value of the Company’s cash, accounts payable and accrued liabilities are considered to be representative of their respective fair values due to the short-term nature of those instruments.

Unless terminated earlier by the parties, the term of the License Agreement will continue until the last licensed patent expires in all countries. In May 2024, we entered into a license agreement pursuant to which we received exclusive, worldwide, royalty-bearing, sublicensable rights to certain patents and technology to be used in the development and commercialization of certain products.

Unless terminated earlier by the parties, the term of the License Agreement will continue until the last licensed patent expires in all countries. 125 In May 2024, we entered into a license agreement pursuant to which we received exclusive, worldwide, royalty-bearing, sublicensable rights to certain patents and technology to be used in the development and commercialization of certain products.

Unless terminated earlier by the parties, the term of the license agreement will continue until the last valid patent claim expires. 121 Additionally, we enter into agreements in the normal course of business with third-party vendors for nonclinical studies, clinical trial related services, research supplies and other services and products for operating purposes.

Unless terminated earlier by the parties, the term of the license agreement will continue until the last valid patent claim expires. Additionally, we enter into agreements in the normal course of business with third-party vendors for nonclinical studies, clinical trial related services, research supplies and other services and products for operating purposes.

Unless terminated earlier by the parties, the term of the License Agreement will continue until the last licensed patent expires in all countries. 13. Related Party Transactions Lease Agreement In February 2021, the Company entered into the Lease with Crossing Holdings, LLC to rent laboratory and office space.

As a basis for considering such assumptions, the accounting guidance establishes a three-tier fair value hierarchy, which prioritizes the inputs used in measuring fair value as follows: 134 Level 1: Observable inputs such as quoted prices in active markets. Level 2: Inputs, other than the quoted prices in active markets that are observable either directly or indirectly.

As a basis for considering such assumptions, the accounting guidance establishes a three-tier fair value hierarchy, which prioritizes the inputs used in measuring fair value as follows: Level 1: Observable inputs such as quoted prices in active markets. Level 2: Inputs, other than the quoted prices in active markets that are observable either directly or indirectly.

In March 2020, the Consulting Agreement was terminated and replaced with an amended consulting agreement (the “2020 Consulting Agreement”), which provides for the similar services and use of office space for a monthly fee of $ 20,000 . Pursuant to the terms of the 2020 Consulting Agreement, it shall remain in effect until otherwise terminated.

In March 2020, the 2019 Consulting Agreement was terminated and replaced with an amended consulting agreement (the “2020 Consulting Agreement”), which provides for the similar services and use of office space for a monthly fee of $ 20,000 . Pursuant to the terms of the 2020 Consulting Agreement, it shall remain in effect until otherwise terminated.

Termination may occur at any time upon mutual agreement or unilaterally upon 30 days’ written notice. If the Company unilaterally terminates the 2020 Consulting Agreement for any reason other than cause, it would be subject to a $ 240,000 termination fee.

Termination may occur at any time upon mutual agreement or unilaterally upon 30 days’ written notice. If the Company unilaterally terminates the 2020 Consulting Agreement for any reason other than 148 cause, it would be subject to a $ 240,000 termination fee.

Depending on the nature of the services provided, the sensitivity of the Information Systems and Data at issue, and the identity of the provider, these processes may include a risk assessment of the vendor, security 111 questionnaire, security assessments, security assessment calls with the vendor’s security personnel and imposition of contractual obligations on the vendor.

Depending on the nature of the services provided, the sensitivity of the Information Systems and Data at issue, and the identity of the provider, these processes may include a risk assessment of the vendor, security questionnaire, security assessments, security assessment calls with the vendor’s security personnel and imposition of contractual obligations on the vendor.

In March 2022, the Company entered into the Lease Amendment with Crossing Holdings, LLC amending the Lease for additional space in the same building. Dr. Pratik Shah and entities that he controls are the sole members of Crossing Holdings, LLC.

Pratik Shah and entities that he controls are the sole members of Crossing Holdings, LLC. In March 2022, the Company entered into the Lease Amendment with Crossing Holdings, LLC amending the Lease for additional space in the same building.

The Company does not believe any of the NOL and credit carryforwards generated through December 31, 2021 would expire solely as a result of annual limitations on the utilization of those attributes.

The 145 Company does not believe any of the NOL and credit carryforwards generated through December 31, 2021 would expire solely as a result of annual limitations on the utilization of those attributes.

Regardless of outcome, litigation can have an adverse impact on us due to defense and settlement costs, diversion of management resources, negative publicity and reputation harm, and other factors. It em 4. Mine Safety Disclosures. Not applicable. 112 PART II It em 5. Market for Registrant’s Common Equity, Related Stockholder Matters and Issuer Purchases of Equity Securities.

Regardless of outcome, litigation can have an adverse impact on us due to defense and settlement costs, diversion of management resources, negative publicity and reputation harm, and other factors. It em 4. Mine Safety Disclosures. Not applicable. 116 PART II It em 5. Market for Registrant’s Common Equity, Related Stockholder Matters and Issuer Purchases of Equity Securities.

Further, we may be required to pay sublicense fees in the mid-single digits percentage for fees, royalties or other payments earned from the granting of sublicenses to the WARF patents and know-how. The Company will recognize these milestone payments and royalties when paid or payable. There were no additional payments or royalties recorded through December 31, 2024.

The information required by this item and not set forth below will be set forth in the sections headed Election of Directors, Executive Officers and Information Regarding the Board of Directors and Corporate Governance contained in the Proxy Statement for our 2025 annual meeting of stockholders, to be filed with the Securities and Exchange Commission on or before April 30, 2025 (the “Proxy Statement”).

The information required by this item and not set forth below will be set forth in the sections headed Election of Directors, Executive Officers and Information Regarding the Board of Directors and Corporate Governance contained in the Proxy Statement for our 2026 annual meeting of stockholders, to be filed with the Securities and Exchange Commission on or before April 30, 2026 (the “Proxy Statement”).

In addition, the number of shares of common stock available for issuance under the 2021 Plan will automatically increase on January 1 of each calendar year through January 1, 2031 in an amount equal to 5% of the total number of shares outstanding of the Company’s common stock on the last day of the calendar month before the date of each automatic increase, or a lesser number of shares determined by the Company’s board of directors.

In addition, the number of shares of common stock available for issuance under the 2021 Plan automatically increases on January 1 of each calendar year through January 1, 2031 in an amount equal to 5% of the total number of shares outstanding of the Company’s common stock on the last day of the calendar month before the date of each automatic increase, or a lesser number of shares determined by the Company’s board of directors.

Further, the Company may be required to pay sublicense fees in the mid-single digits percentage for fees, royalties or other payments earned from the granting of sublicenses to the WARF patents and know-how. The Company will recognize these milestone payments and royalties when paid or payable. There were no additional payments or royalties recorded through December 31, 2024.

An impairment loss is recorded if and when events and circumstances indicate that assets might be impaired and the undiscounted cash flows estimated to be generated by those assets are less than the carrying amount of those assets. The Company has no t recognized any impairment losses for the years ended December 31, 2024 and 2023.

T he Company’s management of segment profit or loss and assets are evaluated at the consolidated level, and it manages its research activities on a consolidated basis. 131 Concentrations of Credit Risk Financial instruments that potentially subject the Company to significant concentrations of credit risk consist primarily of cash, cash equivalents and investment securities.

T he Company’s management of segment profit or loss and assets are evaluated at the consolidated level, and it manages its research activities on a consolidated basis. 135 Concentrations of Credit Risk Financial instruments that potentially subject the Company to significant concentrations of credit risk consist primarily of cash, cash equivalents and investment securities.

The Company had no such contingent liabilities as of December 31, 2024 or December 31, 2023. 12. License Agreements In May 2024, the Company entered into a license agreement pursuant to which it received exclusive, worldwide, royalty-bearing, sublicensable rights to certain patents and technology to be used in the development and commercialization of certain products.

The Company had no such contingent liabilities as of December 31, 2025 or December 31, 2024 . 12. License Agreements In May 2024, the Company entered into a license agreement pursuant to which it received exclusive, worldwide, royalty-bearing, sublicensable rights to certain patents and technology to be used in the development and commercialization of certain products.

The Company’s CODM is its chief executive officer. The CODM primarily utilizes long-range financial projections and cash runway in order to allocate resources and to assess performance. As of December 31, 2024, the Company has no revenue and all the Company’s long-lived assets were located within the United States.

The Company’s CODM is its chief executive officer . The CODM primarily utilizes long-range financial projections and cash runway in order to allocate resources and to assess performance. As of December 31, 2025 , the Company has no revenue and all the Company’s long-lived assets were located within the United States.

It em 6. [Reserved]. 113 It em 7. Management’s Discussion and Analysis of Financial Condition and Results of Operations. You should read the following discussion and analysis of our financial condition and results of operations together with our financial statements and notes thereto included in “Item 8. Financial Statements and Supplementary Data” of this Annual Report on Form 10-K.

It em 6. [Reserved]. 117 It em 7. Management’s Discussion and Analysis of Financial Condition and Results of Operations. You should read the following discussion and analysis of our financial condition and results of operations together with our financial statements and notes thereto included in “Item 8. Financial Statements and Supplementary Data” of this Annual Report on Form 10-K.

In our opinion, the financial statements present fairly, in all material respects, the financial position of the Company at December 31, 2024 and 2023, and the results of its operations and its cash flows for each of the two years in the period ended December 31, 2024, in conformity with U.S. generally accepted accounting principles.

In our opinion, the financial statements present fairly, in all material respects, the financial position of the Company at December 31, 2025 and 2024, and the results of its operations and its cash flows for each of the two years in the period ended December 31, 2025, in conformity with U.S. generally accepted accounting principles.

If we make any substantive amendments to the Code of Business Conduct and Ethics or grants any waiver from a provision of the Code of Business Conduct and Ethics to any executive officer or director that are required to be disclosed pursuant to SEC rules, we will promptly disclose the nature of the amendment or waiver on our website.

If we make any substantive amendments to the Code of Business Conduct and Ethics or grants any waiver from a provision of the Code of Business Conduct and Ethics to any executive officer or director that are required to be disclosed pursuant to SEC rules, we intend to promptly disclose the nature of the amendment or waiver on our website.

We are responsible for reimbursing WARF for costs incurred in connection with prosecuting and maintaining patent rights that are specific to the License Agreement. Expenses recognized in connection with legal patent fees under this License Agreement were immaterial for each of the years ended December 31, 2024 and 2023.

Ansari, Ph.D., dated December 27, 2017, as amended (incorporated by reference to Exhibit 10.12 to the Registrant’s Registration Statement on Form S-1, as amended, filed March 22, 2021). 10.13* Third Amendment to Consulting Agreement, by and between the Registrant and Aseem Z.

Ansari, Ph.D., dated December 27, 2017, as amended (incorporated by reference to Exhibit 10.12 to the Registrant’s Registration Statement on Form S-1, as amended, filed March 22, 2021). 10.14* Third Amendment to Consulting Agreement, by and between the Registrant and Aseem Z.

The Company is responsible for reimbursing WARF for costs incurred in connection with prosecuting and maintaining patent rights that are specific to the License Agreement. Expenses recognized in connection with legal patent fees under this License Agreement were immaterial for the years ended December 31, 2024 and 2023.

The Company had no accrued interest or penalties related to income tax matters on its balance sheets at December 31, 2024 or 2023, and has no t recognized interest or penalties in its statements of operations and comprehensive loss for the years ended December 31, 2024 and 2023, respectively.

The Company had no accrued interest or penalties related to income tax matters on its balance sheets at December 31, 2025 or 2024, and has no t recognized interest or penalties in its statements of operations and comprehensive loss for the years ended December 31, 2025 and 2024, respectively.

Management has assessed the effectiveness of our internal control over financial reporting based on the framework set forth by the Committee of Sponsoring Organizations of the Treadway Commission (COSO) in Internal Control-Integrated Framework (2013 framework). Based on our evaluation, management has concluded that our internal control over financial reporting was effective as of December 31, 2024.

Changes in Internal Control over Financial Reporting There were no changes in our internal control over financial reporting that occurred during the quarter ended December 31, 2024 that have materially affected, or are reasonably likely to materially affect, our internal control over financial reporting. It em 9B. Other Information. None . It em 9C.

Changes in Internal Control over Financial Reporting There were no changes in our internal control over financial reporting that occurred during the quarter ended December 31, 2025 that have materially affected, or are reasonably likely to materially affect, our internal control over financial reporting. It em 9B. Other Information. None . It em 9C.

The information required by this item will be set forth in the sections headed Ratification of Selection of Independent Registered Public Accounting Firm contained in the Proxy Statement and is incorporated herein by reference. 148 PART IV It em 15.

Net cash provided by financing activities for each of the years ended December 31, 2024 and 2023 was comprised of proceeds received from the issuance of common stock through our employee stock purchase plan and from employee stock option exercises.

Net cash provided by financing activities for each of the years ended December 31, 2025 and 2024 was comprised of proceeds received from the issuance of common stock through our employee stock purchase plan and from employee stock option exercises.

(the Company) as of December 31, 2024 and 2023, the related statements of operations, comprehensive loss, stockholders' equity and cash flows for each of the two years in the period ended December 31, 2024, and the related notes (collectively referred to as the “financial statements”).

(the Company) as of December 31, 2025 and 2024 , the related statements of operations, comprehensive loss, stockholders' equity and cash flows for each of the two years in the period ended December 31, 2025, and the related notes (collectively referred to as the “financial statements”).

Evaluation of Disclosure Controls and Procedures As required by Rules 13a-15(b) and 15d-15(b) of the Exchange Act, our management with the participation of our Chief Executive Officer and principal financial officer, evaluated the effectiveness of our disclosure controls and procedures as of December 31, 2024.

In December 2023, the FASB issued ASU 2023-09, ASC Topic 740, Income Taxes: Improvements to Income Tax Disclosures, which requires disaggregated information about a reporting entity’s effective tax rate reconciliation as well as information on income taxes paid. ASU 2023-09 is effective for fiscal years beginning after December 15, 2024, with early adoption permitted.

Accounting Standards Updates In December 2023, the FASB issued ASU 2023-09, ASC Topic 740, Income Taxes: Improvements to Income Tax Disclosures, which requires disaggregated information about a reporting entity’s effective tax rate reconciliation as well as information on income taxes paid. ASU 2023-09 is effective for fiscal years beginning after December 15, 2024 , with early adoption permitted.

The decrease in net cash provided by investing activities was primarily due to a net decrease in cash provided from the maturities and purchases of our investment securities during the year ended December 31, 2024 compared to the year ended December 31, 2023.

Based on the evaluation of our disclosure controls and procedures as of December 31, 2024, our Chief Executive Officer and our principal financial officer concluded that, as of such date, our disclosure controls and procedures were effective at the reasonable assurance level.

Based on the evaluation of our disclosure controls and procedures as of December 31, 2025, our Chief Executive Officer and our principal financial officer concluded that, as of such date, our disclosure controls and procedures were effective at the reasonable assurance level.

The expected lease term includes noncancelable lease periods and, when applicable, periods covered by an option to extend the lease if the Company is reasonably certain to exercise that option, as well as periods covered by an option 132 to terminate the lease if the Company is reasonably certain not to exercise the option.

The expected lease term includes noncancelable lease periods and, when applicable, periods covered by an option to extend the lease if the Company is reasonably certain to exercise that option, as well as periods covered by an option 136 to terminate the lease if the Company is reasonably certain not to exercise the option.

The 2022 Shelf Registration Statement permits: (i) the offering, issuance and sale by the Company of up to a maximum aggregate offering price of $ 300.0 million of common stock, preferred stock, debt securities and warrants in one or more offerings and in any combination; and (ii) the offering, issuance and sale by the Company of up to a maximum aggregate offering price of $ 100.0 million of our common stock that may be issued and sold under an "at-the-market ” sales agreement ( the “ATM Program” ).

The 2025 Shelf Registration Statement permits: (i) the offering, issuance and sale by the Company of up to a maximum aggregate offering price of $ 300.0 million of common stock, preferred stock, debt securities and warrants in one or more offerings and in any combination; and (ii) the offering, issuance and sale by the Company of up to a maximum aggregate offering price of $ 100.0 million of the Company's common stock that may be issued and sold under an "at-the-market ” sales agreement ( the “ATM Program” ).

Funding Requirements Based on our current operating plan, we believe that our existing cash, cash equivalents and investments will be sufficient to fund our planned operating expenses and capital expenditure requirements for more than the next 12 months following the date of this Annual Report.

Funding Requirements Based on our current operating plan, we believe that our existing cash, cash equivalents and investment securities will be sufficient to fund our planned operating expenses and capital expenditure requirements for more than the next 12 months following the date of this Annual Report.

Other Information Emerging Growth Company Status We are an emerging growth company, as defined in the Jumpstart Our Business Startups Act, as amended (JOBS Act), and we may remain an emerging growth company until as late as December 31, 2026 (the fiscal year-end following the fifth anniversary of the completion of our initial public offering).

Other Information Emerging Growth Company Status We are an emerging growth company, as defined in the Jumpstart Our Business Startups Act, as amended (JOBS Act), and we will remain an emerging growth company until December 31, 2026 (the fiscal year-end following the fifth anniversary of the completion of our initial public offering).

Research and development expenses are recognized as incurred. Direct costs include: • external research and development expenses incurred under agreements with contract research organizations, consultants and other vendors that conduct our clinical, nonclinical and discovery activities; • expenses related to manufacturing our product candidates for clinical and nonclinical studies; • laboratory supplies; and • license fees.

Direct costs include: • external research and development expenses incurred under agreements with contract research organizations, consultants and other vendors that conduct our clinical, nonclinical and discovery activities; • expenses related to manufacturing our product candidates for clinical and nonclinical studies; • laboratory supplies; and • license fees.

The Company obtains the fair value of its available-for-sale debt securities from a professional pricing service. Level II securities are valued using quoted market prices for similar instruments, non-binding market prices that are corroborated by observable market data and include our investments in marketable debt instruments of government sponsored enterprises. 135 5.

The Company obtains the fair value of its available-for-sale debt securities from a professional pricing service. Level 2 securities are valued using quoted market prices for similar instruments, non-binding market prices that are corroborated by observable market data and include our investments in marketable debt instruments of government sponsored enterprises. 139 5.

Ite m 3. Legal Proceedings. From time to time, we may be involved in legal proceedings arising in the ordinary course of our business. We are not presently a party to any legal proceedings that, in the opinion of management, would have a material adverse effect on our business.

From time to time, we may be involved in legal proceedings arising in the ordinary course of our business. We are not presently a party to any legal proceedings that, in the opinion of management, would have a material adverse effect on our business.

Ite m 7A. Quantitative and Qualitative Disclosures About Market Risk. As a "smaller reporting company," we are not required to provide the information otherwise required by this item. 123 Ite m 8. Financial Statements and Supplementary Data.

Quantitative and Qualitative Disclosures About Market Risk. As a "smaller reporting company," we are not required to provide the information otherwise required by this item. 127 Ite m 8. Financial Statements and Supplementary Data.

Employee Benefit Plans The Company maintains a retirement plan, which is qualified under section 401(k) of the Code. The plan allows eligible employees to defer, at the employee's discretion, pretax compensation up to the IRS annual limits.

Employee Benefit Plans The Company maintains a retirement plan, which is qualifie d under section 401(k) of the Code. The plan allows eligible employees to defer, at the employee's discretion, pretax compensation up to the IRS annual limits.

There were 12 and 71 securities in an unrealized loss position at December 31, 2024 and 2023, respectively. The Company determined that unrealized losses on its available-for-sale investment securities were primarily attributable to changes in interest rates. Each security remained at a high credit quality rating.

There were 4 and 12 securities in an unrealized loss position at December 31, 2025 and 2024, respectively. The Company determined that unrealized losses on its available-for-sale investment securities were primarily attributable to changes in interest rates. Each security remained at a high credit quality rating.

As of December 31, 2024, unrecognized compensation expense related to ESPP rights was $ 0.5 million, which is expected to be recognized over a remaining period of 1.9 years. 10. Income Taxes The Company is subject to taxation in the United States and various state jurisdictions.

As of December 31, 2025, unrecognized compensation expense related to ESPP rights was $ 0.6 million, which is expected to be recognized over a remaining period of 1.9 years. 10. Income Taxes The Company is subject to taxation in the United States and various state jurisdictions.

The Company elected to make matching contributions of $ 0.4 million and $ 0.5 million to the plan for the years ended December 31, 2024 and 2023, respectively. 146 It em 9. Changes in and Disagreements with Accountants on Accounting and Financial Disclosure. None. I tem 9A. Controls and Procedures.

The Company elected to make matching contributions of $ 0.5 million and $ 0.4 million to the plan for the years ended December 31, 2025 and 2024 , respectively. 149 It em 9. Changes in and Disagreements with Accountants on Accounting and Financial Disclosure. None. I tem 9A. Controls and Procedures.

Disclosure Regarding Foreign Jurisdictions that Prevent Inspections. None. 147 PART III It em 10. Directors, Executive Officers and Corporate Governance.

Disclosure Regarding Foreign Jurisdictions that Prevent Inspections. None. 150 PART III It em 10. Directors, Executive Officers and Corporate Governance.

Section 1350, as Adopted Pursuant to Section 906 of the Sarbanes-Oxley Act of 2002. 97.1 Incentive Compensation Recoupment Policy of the Registrant (incorporated by reference to Exhibit 97.1 to the Registrant’s Annual Report on Form 10-K for the year ended December 31, 2023, filed March 19, 2024). 101.INS Inline XBRL Instance Document – the instance document does not appear in the Interactive Data File because XBRL tags are embedded within the Inline XBRL document. 101.SCH Inline XBRL Taxonomy Extension Schema Document 101.CAL Inline XBRL Taxonomy Extension Calculation Linkbase Document 101.DEF Inline XBRL Taxonomy Extension Definition Linkbase Document 101.LAB Inline XBRL Taxonomy Extension Label Linkbase Document 101.PRE Inline XBRL Taxonomy Extension Presentation Linkbase Document 104 Cover Page Interactive Data File (embedded within the Inline XBRL document) * Indicates management contract or compensatory plan. Schedules have been omitted pursuant to Item 601(a)(5) of Regulation S-K.

Section 1350, as Adopted Pursuant to Section 906 of the Sarbanes-Oxley Act of 2002. 97.1 Incentive Compensation Recoupment Policy of the Registrant (incorporated by reference to Exhibit 97.1 to the Registrant’s Annual Report on Form 10-K for the year ended December 31, 2023, filed March 19, 2024). 101.INS Inline XBRL Instance Document – the instance document does not appear in the Interactive Data File because XBRL tags are embedded within the Inline XBRL document. 101.SCH Inline XBRL Taxonomy Extension Schema With Embedded Linkbase Documents 104 Cover Page Interactive Data File (embedded within the Inline XBRL document) * Indicates management contract or compensatory plan. Schedules have been omitted pursuant to Item 601(a)(5) of Regulation S-K.

In addition, the Company has federal and state research and development (“R&D”) credit carryforwards totali ng $ 9.0 million and $ 3.2 million, respectively. The federal R&D credit carryforwards will begin to expire in 2038 unless previously utilized. The state R&D credit carryforwards do not expire.

In addition, the Company has federal and state research and development (“R&D”) credit carryforwards totali ng $ 11.0 million and $ 4.2 million, respectively. The federal R&D credit carryforwards will begin to expire in 2038 unless previously utilized. The state R&D credit carryforwards do not expire.

Form 1 0-K Summary None. 150 SIGNATURES Pursuant to the requirements of Section 13 or 15(d) of the Securities Exchange Act of 1934, as amended, the Registrant has duly caused this Report to be signed on its behalf by the undersigned, thereunto duly authorized . Design Therapeutics, Inc. Date: March 10, 2025 By: /s/ Pratik Shah, Ph.D. Pratik Shah, Ph.D.

Form 1 0-K Summary None. 153 SIGNATURES Pursuant to the requirements of Section 13 or 15(d) of the Securities Exchange Act of 1934, as amended, the Registrant has duly caused this Report to be signed on its behalf by the undersigned, thereunto duly authorized . Design Therapeutics, Inc. Date: March 9, 2026 By: /s/ Pratik Shah, Ph.D. Pratik Shah, Ph.D.

We may also be required to pay royalties based on annual net product sales in the low single digits on our or our sublicensees’ net product sales on a country-by-country and product-by-product basis, and are subject to a minimum royalty of $100,000 per calendar year upon first commercial product sale.

We may also be required to pay royalties based on annual net product sales in the low single digits on our or our sublicensees’ net product sales on a country-by-country and product-by-product basis, and are subject to a minimum royalty of $0.1 million per calendar year upon first commercial product sale.

As consideration for the license, the Company agreed to pay an upfront fee of $ 0.3 million, which the Company immediately expensed as research and development expense in its statements of operations as there was no alternative future use for the license. 143 In 2022, pursuant to the License Agreement, the Company paid $ 0.1 million upon the acceptance of an Investigational New Drug Application ( “ IND”) in the U.S.

As consideration for the license, the Company agreed to pay an upfront fee of $ 0.3 million, which the Company immediately expensed as research and development expense in its statements of operations as there was no alternative future use for the license. 147 In 2022, pursuant to the License Agreement, the Company paid $ 0.1 million upon the acceptance of an Investigational New Drug Application ( “ IND”) in the United States.

The audit committee also receives and has access to various reports, summaries or presentations related to cybersecurity threats, risk and mitigation. It em 2. Properties. We lease approximately 12,370 square feet of laboratory and office space in Carlsbad, California, pursuant to a lease agreement, with a related party, that commenced in September 2021 and expires in August 2027.

The audit committee also receives and has access to various reports, summaries or presentations related to cybersecurity threats, risk and mitigation. It em 2. Properties. We lease approximately 12,370 square feet of laboratory and office space in Carlsbad, California, pursuant to a lease agreement that commenced in September 2021 and expires in December 2029.

As of December 31, 2024, the weighed-average remaining lease term for the Company's leases was 2.7 years and the weighted-average discount rate used to determine the right-of-use asset and corresponding operating lease liability was 7.37 %.

As of December 31, 2025, the weighed-average remaining lease term for the Company's leases was 1 .7 years and the weighted-average discount rate used to determine the right-of-use asset and corresponding operating lease liability was 7.37 %.

The Company’s currently available cash and cash equivalents as of December 31, 2024 are sufficient to meet its anticipated cash requirements for more than 12 months following the date the financial statements are issued . 2.

The Company’s currently available cash, cash equivalents and investment securities as of December 31, 2025 are sufficient to meet its anticipated cash requirements for more than 12 months following the date the financial statements are issued . 2.

Rent, and related operating expenses recognized by the Company under the Lease and Lease Amendment during the periods presented were as follows (in thousands): Year Ended December 31, 2024 2023 Research and development $ 848 $ 845 General and administrative 297 298 Total expenses $ 1,145 $ 1,143 Consulting Agreements In January 2019, the Company entered into an agreement with the Marlinspike Group, LLC (“Marlinspike Group”) for research support, management, and business consulting services (the “2019 Consulting Agreement”).

Rent and related operating expenses recognized by the Company under the Lease and Lease Amendment during the periods presented were as follows (in thousands): Year Ended December 31, 2025 2024 Research and development $ 872 $ 848 General and administrative 288 297 Total expenses $ 1,160 $ 1,145 Consulting Agreements In January 2019, the Company entered into an agreement with the Marlinspike Group, LLC (“Marlinspike Group”) for research support, management, and business consulting services (the “2019 Consulting Agreement”).

Further, Marlinspike Group provides the use of approximately 2,120 square feet of its office space in Carlsbad, California to the Company on an as-available basis from time to time pursuant to the agreement. The Company’s Chief Executive Officer and Chairperson of its board of directors is an executive officer of Marlinspike Group.

Further, Marlinspike Group provides the use of its office space in Carlsbad, California to the Company on an as-available basis from time to time pursuant to the agreement. The Company’s Chief Executive Officer and Chairperson of its board of directors is an executive officer of Marlinspike Group.

The 2022 Shelf Registration Statement permits: (i) the offering, issuance and sale by us of up to a maximum aggregate offering price of $300.0 million of common stock, preferred stock, debt securities and warrants in one or more offerings and in any combination; and (ii) the offering, issuance and sale by us of up to a maximum aggregate offering price of $100.0 million of our common stock that may be issued and sold under an "at-the-market” sales agreement (ATM Program).

The 2025 Shelf Registration Statement permits: (i) the offering, issuance and sale by us of up to a maximum aggregate offering price of $300.0 million of common stock, preferred stock, debt securities and warrants in one or more offerings and in any combination; and (ii) the offering, issuance and sale by us of up to a maximum aggregate offering price of $100.0 million of our common stock that may be issued and sold under our ATM Program.

Exhibit Index Exhibit Number Description 3.1 Amended and Restated Certificate of Incorporation (incorporated by reference to Exhibit 3.1 to the Registrant’s Current Report on Form 8-K, filed March 30, 2021). 3.2 Amended and Restated Bylaws (incorporated by reference to Exhibit 3.2 to the Registrant’s Current Report on Form 8-K, filed March 30, 2021). 4.1 Form of Common Stock Certificate (incorporated by reference to Exhibit 4.1 to the Registrant’s Registration Statement on Form S-1, as amended, filed March 22, 2021). 4.2 Amended and Restated Investors’ Rights Agreement, by and between the Registrant and certain of its stockholders, dated January 25, 2021 (incorporated by reference to Exhibit 4.2 to the Registrant’s Registration Statement on Form S-1, filed March 5, 2021). 4.3 Description of the Registrant’s Common Stock (incorporated by reference to Exhibit 4.3 to the Registrant’s Annual Report on Form 10-K for the year ended December 31, 2023, filed March 19, 2024). 10.1* Form of Indemnity Agreement, by and between the Registrant and its directors and officers (incorporated by reference to Exhibit 10.1 to the Registrant’s Registration Statement on Form S-1, filed March 5, 2021). 10.2* Design Therapeutics, Inc. 2018 Equity Incentive Plan, as amended, and Forms of Option Grant notice, Option Agreement, Notice of Exercise, Early Exercise Stock Purchase Agreement, Restricted Stock Grant Notice and Restricted Stock Award Agreement thereunder (incorporated by reference to Exhibit 10.2 to the Registrant’s Registration Statement on Form S-1, filed March 5, 2021). 10.3* Design Therapeutics, Inc. 2021 Equity Incentive Plan, and Forms of Option Grant Notice, Option Agreement and Notice of Exercise thereunder (incorporated by reference to Exhibit 10.3 to the Registrant's Annual Report on Form 10-K for the year ended December 31, 2021, filed with the SEC on March 10, 2022). 10.4* Design Therapeutics, Inc. 2021 Employee Stock Purchase Plan (incorporated by reference to Exhibit 10.4 to the Registrant’s Registration Statement on Form S-1, as amended, filed March 22, 2021). 10.5* Employment Agreement, by and between the Registrant and Pratik Shah, Ph.D., dated March 1, 2020 (incorporated by reference to Exhibit 10.5 to the Registrant’s Registration Statement on Form S-1, filed March 5, 2021). 10.6* Employment Agreement, by and between the Registrant and Sean Jeffries, dated May 21, 2019 (incorporated by reference to Exhibit 10.7 to the Registrant’s Registration Statement on Form S-1, filed March 5, 2021). 149 10.7* Non-Employee Director Compensation Policy of the Registrant (incorporated by reference to Exhibit 10.7 to the Registrant’s Annual Report on Form 10-K for the year ended December 31, 2023, filed March 19, 2024). 10.8 Human Therapeutics Exclusive License Agreement, by and between the Registrant and Wisconsin Alumni Research Foundation, dated February 20, 2019 (incorporated by reference to Exhibit 10.9 to the Registrant’s Registration Statement on Form S-1, filed March 5, 2021). 10.9 * Consulting Agreement, by and between the Registrant and Marlinspike Group, LLC, dated March 1, 2020 (incorporated by reference to Exhibit 10.10 to the Registrant’s Registration Statement on Form S-1, filed March 5, 2021). 10.10* Lease, by and between the Registrant and Crossing Holdings, LLC, dated February 2, 2021 (incorporated by reference to Exhibit 10.11 to the Registrant’s Registration Statement on Form S-1, as amended, filed March 5, 2021). 10.11* First Amendment to Lease Agreement, by and between the Registrant and Crossing Holdings, LLC, dated March 18, 2022 (incorporated by reference to Exhibit 10.1 to the Registrant's Current Report on Form 8-K, filed March 22, 2022). 10.12* Consulting Agreement, by and between the Registrant and Aseem Z.

Exhibit Index Exhibit Number Description 3.1 Amended and Restated Certificate of Incorporation (incorporated by reference to Exhibit 3.1 to the Registrant’s Current Report on Form 8-K, filed March 30, 2021). 3.2 Amended and Restated Bylaws (incorporated by reference to Exhibit 3.2 to the Registrant’s Current Report on Form 8-K, filed March 30, 2021). 4.1 Form of Common Stock Certificate (incorporated by reference to Exhibit 4.1 to the Registrant’s Registration Statement on Form S-1, as amended, filed March 22, 2021). 4.2 Amended and Restated Investors’ Rights Agreement, by and between the Registrant and certain of its stockholders, dated January 25, 2021 (incorporated by reference to Exhibit 4.2 to the Registrant’s Registration Statement on Form S-1, filed March 5, 2021). 4.3 Description of the Registrant’s Common Stock (incorporated by reference to Exhibit 4.3 to the Registrant’s Annual Report on Form 10-K for the year ended December 31, 2023, filed March 19, 2024). 10.1* Form of Indemnity Agreement, by and between the Registrant and its directors and officers (incorporated by reference to Exhibit 10.1 to the Registrant’s Registration Statement on Form S-1, filed March 5, 2021). 10.2* Design Therapeutics, Inc. 2018 Equity Incentive Plan, as amended, and Forms of Option Grant notice, Option Agreement, Notice of Exercise, Early Exercise Stock Purchase Agreement, Restricted Stock Grant Notice and Restricted Stock Award Agreement thereunder (incorporated by reference to Exhibit 10.2 to the Registrant’s Registration Statement on Form S-1, filed March 5, 2021). 10.3* Design Therapeutics, Inc. 2021 Equity Incentive Plan, and Forms of Option Grant Notice, Option Agreement and Notice of Exercise thereunder. 10.4* Design Therapeutics, Inc. 2021 Employee Stock Purchase Plan (incorporated by reference to Exhibit 10.4 to the Registrant’s Registration Statement on Form S-1, as amended, filed March 22, 2021). 10.5* Employment Agreement, by and between the Registrant and Pratik Shah, Ph.D., dated March 1, 2020 (incorporated by reference to Exhibit 10.5 to the Registrant’s Registration Statement on Form S-1, filed March 5, 2021). 10.6* Employment Agreement, by and between the Registrant and Sean Jeffries, dated May 21, 2019 (incorporated by reference to Exhibit 10.7 to the Registrant’s Registration Statement on Form S-1, filed March 5, 2021). 10.7* Employment Agreement, by and between the Registrant and Chris Storgard, dated April 9, 2025. 152 10.8* Non-Employee Director Compensation Policy of the Registrant (incorporated by reference to Exhibit 10.7 to the Registrant’s Annual Report on Form 10-K for the year ended December 31, 2023, filed March 19, 2024). 10.9 Human Therapeutics Exclusive License Agreement, by and between the Registrant and Wisconsin Alumni Research Foundation, dated February 20, 2019 (incorporated by reference to Exhibit 10.9 to the Registrant’s Registration Statement on Form S-1, filed March 5, 2021). 10.10 * Consulting Agreement, by and between the Registrant and Marlinspike Group, LLC, dated March 1, 2020 (incorporated by reference to Exhibit 10.10 to the Registrant’s Registration Statement on Form S-1, filed March 5, 2021). 10.11 Lease, by and between the Registrant and TREF V Hidden Valley Owner LLC (as successor in interest, via assignment), dated February 2, 2021 (incorporated by reference to Exhibit 10.11 to the Registrant’s Registration Statement on Form S-1, as amended, filed March 5, 2021). 10.12 First Amendment to Lease Agreement, by and between the Registrant and TREF V Hidden Valley Owner LLC (as successor in interest, via assignment), dated March 18, 2022 (incorporated by reference to Exhibit 10.1 to the Registrant's Current Report on Form 8-K, filed March 22, 2022). 10.13* Consulting Agreement, by and between the Registrant and Aseem Z.

President, Chief Executive Officer and Chairperson (Principal Executive and Financial Officer) March 10, 2025 Pratik Shah, Ph.D. /s/ Julie Burgess Chief Accounting Officer (Principal Accounting Officer) March 10, 2025 Julie Burgess /s/ Simeon George, M.D. Director March 10, 2025 Simeon George, M.D. /s/ Rodney Lappe, Ph.D.

President, Chief Executive Officer and Chairperson (Principal Executive and Financial Officer) March 9, 2026 Pratik Shah, Ph.D. /s/ Julie Burgess Chief Accounting Officer (Principal Accounting Officer) March 9, 2026 Julie Burgess /s/ Simeon George, M.D. Director March 9, 2026 Simeon George, M.D. /s/ Rodney Lappe, Ph.D.

Further, the Company is not currently under examination by any federal, state or local tax authority. At December 31, 2024, the Company had federal and state net operating loss (“NOL”) carryforwards of $ 86.4 million an d $ 11.1 million, r espectively. Federal NOL carryforwards totaling $ 0.1 million b egin to expire in 2037 , unless previously utilized.

Further, the Company is not currently under examination by any federal, state or local tax authority. At December 31, 2025, the Company had federal and state net operating loss (“NOL”) carryforwards of $ 145.5 million an d $ 13.1 million, r espectively. Federal NOL carryforwards totaling $ 0.1 million b egin to expire in 2037 , unless previously utilized.

We then shifted focus to developing DT-216 with a potentially improved formulation to enable higher exposure and chronic administration for treatment of FA. These efforts resulted in a new product candidate, DT-216P2, which uses the same drug substance, DT-216.

We then shifted focus to developing DT-216 with a potentially improved formulation to enable more sustained exposure for the treatment of FA. These efforts resulted in a new product candidate, DT-216P2, which uses the same drug substance, DT-216.

The following table summarizes the Company’s financial instruments measured at fair value on a recurring basis at December 31, 2024 and 2023 (in thousands): Fair Value Measurement at End of Period Using: Quoted Prices In Active Markets Significant For Other Significant Identical Observable Unobservable Assets Inputs Inputs Total (Level 1) (Level 2) (Level 3) As of December 31, 2024: Assets: Money market funds (1) $ 20,800 $ 20,800 $ — $ — Certificates of deposit 2,898 2,898 — — U.S.

The following table summarizes the Company’s financial instruments measured at fair value on a recurring basis at December 31, 2025 and 2024 (in thousands): Fair Value Measurement at End of Period Using: Quoted Prices In Active Markets Significant For Other Significant Identical Observable Unobservable Assets Inputs Inputs Total (Level 1) (Level 2) (Level 3) As of December 31, 2025: Assets: Money market funds (1) $ 15,141 $ 15,141 $ — $ — U.S.

The Company’s lead product candidate is in Friedreich ataxia (“FA”), its second product candidate is in Fuchs endothelial corneal dystrophy (“FECD”), and it is also advancing GeneTAC ® programs to address other diseases.

The Company’s lead product candidate is in Friedreich ataxia (“FA”), its second product candidate is in Fuchs endothelial corneal dystrophy (“FECD”), its third product candidate is in myotonic dystrophy type-1 (DM1), and it is also advancing GeneTAC ® programs to address other diseases.

(incorporated by reference to Exhibit 10.13 to the Registrant’s Annual Report on Form 10-K for the year ended December 31, 2023, filed March 19, 2024). 19.1 Insider Trading Policy of the Registrant. 23.1 Consent of Independent Registered Public Accounting Firm 24.1 Power of Attorney (see signature page hereto). 31.1 Certification of Principal Executive and Financial Officer Pursuant to Rules 13a-14(a) and 15d-14(a) under the Securities Exchange Act of 1934, as Adopted Pursuant to Section 302 of the Sarbanes-Oxley Act of 2002. 32.1 Certification of Principal Executive and Financial Officer Pursuant to 18 U.S.C.

Ansari, Ph.D., dated November 9, 2023 (incorporated by reference to Exhibit 10.13 to the Registrant’s Annual Report on Form 10-K for the year ended December 31, 2023, filed March 19, 2024). 10.15* Consulting Agreement by and between the Registrant and Rodney Lappe, Ph.D., dated November 22, 2023 (incorporated by reference to Exhibit 10.14 to the Registrant’s Annual Report on Form 10-K for the year ended December 31, 2023, filed March 19, 2024). 19.1 Insider Trading Policy of the Registrant (incorporated by reference to Exhibit 19.1 to the Registrant’s Annual Report on Form 10-K for the year ended December 31, 2024, filed March 10, 2025). 23.1 Consent of Independent Registered Public Accounting Firm 24.1 Power of Attorney (see signature page hereto). 31.1 Certification of Principal Executive and Financial Officer Pursuant to Rules 13a-14(a) and 15d-14(a) under the Securities Exchange Act of 1934, as Adopted Pursuant to Section 302 of the Sarbanes-Oxley Act of 2002. 32.1 Certification of Principal Executive and Financial Officer Pursuant to 18 U.S.C.

Based on the baseline characteristics data, we have chosen approximately 100 patients for future follow-up visits. This will inform our clinical development efforts and we believe it could potentially increase the probability of DT-168 programmatic success. Our third program based on the GeneTAC ® platform is focused on DM1.

We may be obligated to make aggregate regulatory milestone payments of up to $0.8 million for each product incorporating licensed patent rights and pay a royalty on worldwide net sales on a product-by-product basis. The Company will recognize these milestone payments and royalties when paid or payable. There were no additional payments or royalties recorded through December 31, 2024.

Our future capital requirements will depend on many factors, including: • the scope, rate of progress and costs of our drug discovery, nonclinical development activities and clinical trials for any product candidates; • the number and scope of clinical programs we decide to pursue; • the scope and costs of designing and implementing drug product improvements (including alternate formulations) and manufacturing our product candidates and any future commercial manufacturing activities; • the emergence of competing therapies and other adverse market developments; 119 • the cost, timing and outcome of seeking FDA, European Medicines Agency (EMA) and any other regulatory approvals for any product candidates; • the costs of preparing, filing and prosecuting patent applications, maintaining and enforcing our intellectual property rights and defending intellectual property-related claims; • the terms and timing of establishing and maintaining strategic collaborations, licenses and other similar arrangements and the financial terms of such agreements; • our efforts to enhance operational systems and our ability to attract, hire and retain qualified personnel, including personnel to support the development of our product candidates; • the costs associated with being a public company; • the timing of any milestone and royalty payments to our current and future licensors; • the extent to which we acquire or in-license other product candidates and technologies; • our need and ability to retain key management and hire scientific, technical, business, and medical personnel; • our implementation of additional internal systems and infrastructure, including operational, financial and management information systems; • the costs associated with expanding our facilities or building out additional laboratory space; and • the cost associated with commercialization activities for any of our current or future product candidates, if approved.

Our future capital requirements will depend on many factors, including: • the scope, rate of progress and costs of our drug discovery, nonclinical development activities and clinical trials for any product candidates; • the number and scope of clinical programs we decide to pursue; • the scope and costs of designing and implementing drug product improvements (including alternate formulations) and manufacturing our product candidates and any future commercial manufacturing activities; • the emergence of competing therapies and other adverse market developments; • the cost, timing and outcome of seeking FDA, European Medicines Agency (EMA) and any other regulatory approvals for any product candidates; • the costs of preparing, filing and prosecuting patent applications, maintaining and enforcing our intellectual property rights and defending intellectual property-related claims; • the terms and timing of establishing and maintaining strategic collaborations, licenses and other similar arrangements and the financial terms of such agreements; • our efforts to enhance operational systems and our ability to attract, hire and retain qualified personnel, including personnel to support the development of our product candidates; • the costs associated with being a public company; • the timing of any milestone and royalty payments to our current and future licensors; • the extent to which we acquire or in-license other product candidates and technologies; • our need and ability to retain key management and hire scientific, technical, business, and medical personnel; • our implementation of additional internal systems and infrastructure, including operational, financial and management information systems; • the costs associated with expanding our facilities or building out additional laboratory space; and • the cost associated with commercialization activities for any of our current or future product candidates, if approved. 124 Until such time, if ever, as we can generate substantial revenues from product sales to support our cost structure, we expect to finance our cash needs through public or private equity offerings, debt financings, or other capital sources which may include strategic collaborations, licensing arrangements or other arrangements with third parties.

INDEX TO FINANCIAL STATEMENTS Report of Independent Registered Public Accounting Firm (PCAOB ID: 42 ) 125 Balance Sheets as of December 31, 2024 and 2023 126 Statements of Operations for the Years ended December 31, 2024 and 2023 127 Statements of Comprehensive Loss for the Years Ended December 31, 2024 and 2023 128 Statements of Stockholders’ Equity for the Years ended December 31, 2024 and 2023 129 Statements of Cash Flows for the Years ended December 31, 2024 and 2023 130 Notes to Financial Statements 131 124 Report of Independent Registered Public Accounting Firm To the Stockholders and the Board of Directors of Design Therapeutics, Inc.

INDEX TO FINANCIAL STATEMENTS Report of Independent Registered Public Accounting Firm (PCAOB ID: 42 ) 129 Balance Sheets as of December 31, 2025 and 2024 130 Statements of Operations for the Years ended December 31, 2025 and 2024 131 Statements of Comprehensive Loss for the Years Ended December 31, 2025 and 2024 132 Statements of Stockholders’ Equity for the Years ended December 31, 2025 and 2024 133 Statements of Cash Flows for the Years ended December 31, 2025 and 2024 134 Notes to Financial Statements 135 128 Report of Independent Registered Public Accounting Firm To the Stockholders and the Board of Directors of Design Therapeutics, Inc.

To date, we have incurred net losses and negative cash flows from operations since our inception and as of December 31, 2024, had an accumulated deficit of $227.2 million.

To date, we have incurred net losses and negative cash flows from operations since our inception and as of December 31, 2025, had an accumulated deficit of $297.0 million.

For the year ended December 31, 2022, pursuant to the License Agreement, we paid $0.1 million to WARF upon the acceptance of an IND in the U.S. and will be required to make further aggregate milestone payments of up to $17.5 million upon achievement of certain other regulatory and commercial milestones.

In 2022, pursuant to the License Agreement, we paid $0.1 million to WARF upon the acceptance of an IND in the United States. We will be required to make further aggregate milestone payments of up to $17.5 million upon achievement of certain other regulatory and commercial milestones.

The weighted average inputs used for the ESPP for the year ended December 31, 2024, were as follows: Year Ended December 31, 2024 2023 Expected term (years) 1.39 1.51 Expected volatility 88.9 % 85.4 % Risk-free interest rate 4.82 % 4.44 % Expected dividend yield 0.0 % 0.0 % 140 Stock-based compensation expense for all equity awards has been reported in the statements of operations and comprehensive loss as follows (in thousands): Year Ended December 31, 2024 2023 Research and development $ 6,575 $ 6,152 General and administrative 6,497 6,936 Total $ 13,072 $ 13,088 As of December 31, 2024, unrecognized compensation expense related to unvested stock option awards was $ 17.1 million, which is expected to be recognized in expense over a weighted-average period of 1.3 years.

The weighted average inputs used for the ESPP for the year ended December 31, 2025, were as follows: Year Ended December 31, 2025 2024 Expected term (years) 1.35 1.39 Expected volatility 89.7 % 88.9 % Risk-free interest rate 3.71 % 4.82 % Expected dividend yield 0.0 % 0.0 % Stock-based compensation expense for all equity awards has been reported in the statements of operations and comprehensive loss as follows (in thousands): Year Ended December 31, 2025 2024 Research and development $ 6,563 $ 6,575 General and administrative 7,986 6,497 Total $ 14,549 $ 13,072 As of December 31, 2025 , unrecognized compensation expense related to unvested stock option awards was $ 20.7 million, which is expected to be recognized in expense over a weighted-average period of 1.3 years.

Maturities of operating lease liabilities, related party as of December 31, 2024 are as follows (in thousands): 2025 $ 945 2026 973 2027 663 Total future minimum lease payments 2,581 Less: Present value adjustment ( 247 ) Operating lease liabilities, related party $ 2,334 Rent expense was $ 0.9 million for each of the years ended December 31, 2024 and 2023. 8.

Maturities of operating lease liabilities, related party as of December 31, 2025 are as follows (in thousands): 2026 973 2027 663 Total future minimum lease payments 1,636 Less: Present value adjustment ( 101 ) Operating lease liabilities, related party $ 1,535 Rent expense was $ 0.9 million for each of the years ended December 31, 2025 and 2024.

As of December 31, 2024, we had used approximately $102.5 million of the net proceeds received from our initial public offering to support our operations.

As of December 31, 2025, we had used approximately $133.7 million of the net proceeds received from our initial public offering to support our operations.

As consideration for the license, we agreed to pay an upfront fee of $0.3 million, which we immediately expensed as a research and development expense in our statements of operations as there was no alternative future use for the license.

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