Korsana Biosciences, Inc.

The Nasdaq Capital Market Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 (§ 230.405 of this chapter) or Rule 12b-2 of the Securities Exchange Act of 1934 (§ 240.12b-2 of this chapter).

Emerging growth company ☐ If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act. ☐

Following the Reverse Stock Split (as defined below), which occurred immediately prior to the Closing of the Merger (as defined below), and as a result of and upon the effective time of the First Merger (as defined below) (the “ First Effective Time ”), (i) each then-outstanding share of common stock, par value $0.0001 per share, of Korsana (the “ Korsana common stock ”) and each then-outstanding share of Series A Preferred Stock, par value $0.0001 per share, of Korsana (the “ Korsana Series A preferred stock ”) (including shares of Korsana common stock issued in the Korsana Pre-Closing Financing (as defined below) and excluding shares canceled pursuant to the Merger Agreement and excluding dissenting shares) automatically converted solely into the right to receive a number of shares of common stock, no par value per share, of Cyclerion (the “ Company common stock ,” and prior to the effective time of the Merger, the “ Cyclerion common stock ”) equal to the Exchange Ratio (as defined below); provided, that to the extent the shares of Company common stock otherwise issuable to any holder would exceed such holder’s beneficial ownership limitation (initially set at a percentage of up to 9.99% of the outstanding Company common stock) (the “ Beneficial Ownership Limitation ”), such holder received, in lieu of the excess shares, pre-funded warrants to purchase an equal number of shares of Company common stock (the “ Merger Pre-Funded Warrants ”); (ii) each then-outstanding share of Series Seed Preferred Stock, par value $0.0001 per share, of Korsana (the “ Korsana Series Seed preferred stock ”) (excluding shares of Korsana Series Seed preferred stock canceled pursuant to the Merger Agreement and dissenting shares) automatically converted into the right to receive a number of shares of Series B Non-Voting Convertible Preferred Stock, no par value per share, of Cyclerion (which are each convertible into 1,000 shares of Company common stock) (the “ Company Series B Preferred Stock ,” and prior to the effective time of the Merger, the “ Cyclerion Series B Preferred Stock ”), equal to the Exchange Ratio divided by 1,000; (iii) each then-outstanding option (a “ Korsana Option ”) to purchase Korsana common stock was assumed by Cyclerion; (iv) each then-outstanding Korsana restricted stock unit was assumed by Cyclerion; (v) each then-outstanding warrant to purchase shares of Korsana common stock, including each pre-funded warrant issued in the Korsana Pre-Closing Financing, was converted into a warrant to purchase shares of Company common stock (each such warrant issued in respect of a Korsana pre-funded warrant, an “ Assumed Pre-Funded Warrant ,” and together with the Merger Pre-Funded Warrants, the “ Company pre-funded warrants ”).

Each share of Cyclerion common stock and Cyclerion Series A Convertible Preferred Stock, no par value per share (the “ Company Series A Preferred Stock ”) that was issued and outstanding at the First Effective Time remained issued and outstanding and such shares, subject to the Reverse Stock Split, were unaffected by the Merger. Prior to the First Effective Time, Cyclerion’s board of directors accelerated the vesting of all options to purchase shares of Cyclerion common stock (“ Cyclerion Options ”) and all restricted stock awards (“ Cyclerion RSAs ”). Each outstanding Cyclerion Option with an exercise price per share equal to or less than the volume weighted average closing trading price of a share of Cyclerion common stock on The Nasdaq Stock Market LLC (“ Nasdaq ”) for the five consecutive trading days ending three trading days prior to the Calculation Date (as defined in the Merger Agreement), as reported by Bloomberg L.P. (the “ Cyclerion Closing Price ” and such Cyclerion Options, “ In-the-Money Cyclerion Options ”), was cancelled at the First Effective Time and each holder thereof received an amount in cash, without interest, less any applicable tax withholding, equal to the product obtained by multiplying the excess of the Cyclerion Closing Price over the exercise price per share of the Cyclerion common stock underlying such Cyclerion Option by the number of shares of the Cyclerion common stock underlying such Cyclerion Option (“ Cyclerion Stock Option Cash Consideration ”). Each Cyclerion Option with an exercise price greater than the Cyclerion Closing Price (an “ Out-of-the-Money Cyclerion Option ”) was cancelled for no consideration.

No fractional shares of Company common stock were issued in connection with the Merger, and no certificates or scrip for any such fractional shares were issued. Any fractional shares of Company common stock resulting from the conversion of shares of Korsana common stock (including shares of Korsana common stock issued in the Korsana Pre-Closing Financing) were issued as follows: (i) one share of Company common stock if the aggregate amount of fractional shares of Company common stock of any individual holder of Korsana capital stock upon conversion was equal to or exceeded 0.50 or (ii) no shares of Company common stock if the aggregate amount of fractional shares of Company common stock of any individual holder of Korsana capital stock upon conversion was less than 0.50, with no cash being paid for any fractional share eliminated by such rounding. Any fractional shares of Company Series B Preferred Stock that a holder of Korsana Series Seed preferred stock would otherwise have been entitled to receive were aggregated with all fractional shares of Company Series B Preferred Stock issuable to such holder and rounded up to the nearest whole share of Company Series B Preferred Stock.

The material provisions of the Merger Agreement are described in Cyclerion’s definitive proxy statement/prospectus filed on Form S-4 with the U.S. Securities and Exchange Commission (the “ SEC ”), which registration statement was most recently amended on July 22, 2026 and declared effective on July 24, 2026 (the “ Proxy Statement/Prospectus ”), in the section entitled “ The Merger Agreement ” beginning on page 168 and are incorporated herein by reference.

The foregoing description of the Merger Agreement is not complete and is subject to and qualified in its entirety by reference to the complete text of the Merger Agreement, copies of which are attached hereto as Exhibits 2.1 and 2.2 and incorporated herein by reference.

Descriptions of the Support Agreements and the Lock-Up Agreements are included in the Proxy Statement/Prospectus in the sections entitled “ Agreements Related to the Merger—Support Agreements ” and “ Agreements Related to the Merger—Lock-Up Agreements ” beginning on page 188 and are incorporated herein by reference.

The foregoing descriptions of the Support Agreements and the Lock-Up Agreements are not complete and are subject to and qualified in their entirety by reference to the complete texts of the Form of Korsana Support Agreement, the Form of Cyclerion Support Agreement and the Form of Lock-Up Agreement, copies of which are attached hereto as Exhibits 10.1, 10.2 and 10.3, respectively, and are incorporated herein by reference.

The Korsana pre-funded warrants have an exercise price per share equal to $0.0001 (as adjusted from time to time as provided in the form of pre-funded warrant) and may be exercised at any time and from time to time after the original issue date. The Korsana pre-funded warrants do not expire. A holder may not exercise any portion of a Korsana pre-funded warrant to the extent that, immediately prior to or after giving effect to such exercise, the holder, together with its attribution parties, would beneficially own shares of common stock in excess of 14.99% of the shares of common stock outstanding immediately following such exercise. A holder may, upon written notice to the Company, increase or decrease such percentage to any other percentage not in excess of 19.99%, provided that any increase will not be effective until the sixty-first (61st) day after such notice is delivered to the Company.

The shares of Korsana common stock and Korsana pre-funded warrants that were issued in the Korsana Pre-Closing Financing were or have the right to be, respectively, converted into shares of Company common stock in the Merger.

In connection with the consummation of the Merger, on the Closing Date:

Korsana issued to the Financing Investors (prior to giving effect to the Exchange Ratio) an aggregate of 140,516,748 shares of Korsana common stock and 20,171,986 Korsana pre-funded warrants for gross proceeds of approximately $380.0 million; and all of the then-outstanding (a) (i) 6,000,000 shares of Korsana common stock, (ii) 75,500,000 shares of Korsana Series A preferred stock, and (iii) 140,516,748 shares of Korsana common stock purchased in the Korsana Pre-Closing Financing were automatically converted into the right to receive a number of shares of Company common stock and/or, to the extent otherwise issuable in excess of the applicable Beneficial Ownership Limitation, Company pre-funded warrants in lieu thereof equal to the exchange ratio calculated in accordance with the Merger Agreement (the “ Exchange Ratio ”); (b) 20,000,000 shares of Korsana Series Seed preferred stock were automatically converted into the right to receive a number of shares of Company Series B Preferred Stock equal to the Exchange Ratio divided by 1,000; (c) 20,171,986 pre-funded warrants purchased in the Korsana Pre-Closing Financing were converted into Company pre-funded warrants equal to the Exchange Ratio; and (d) options exercisable for 34,152,978 shares of Korsana common stock and warrants exercisable for 1,102,561 shares of Korsana common stock (the “ Parasa Warrants ”) were assumed by the Company and became options and warrants, respectively, in respect of shares of Company common stock, with the number of underlying shares and the exercise price adjusted in accordance with the Exchange Ratio.

45,541,425 shares of Company common stock (inclusive of issuances pursuant to the Merger Agreement and the Korsana Pre-Closing Financing);

5,361,846 shares of Company common stock issuable upon the exercise of Company pre-funded warrants, each exercisable for one share of Company common stock at a price of $0.0001 per share; and 4,148,000 shares of Company common stock issuable upon the conversion of Company Series B Preferred Stock.

FORM 10 INFORMATION

Item 2.01(f) of Form 8-K states that if the predecessor registrant was a “shell company” (as such term is defined in Rule 12b-2 under the Securities Exchange Act of 1934, as amended (the “ Exchange Act ”)), as Cyclerion was immediately before the Merger, then the registrant must disclose the information that would be required if the registrant were filing a general form for registration of securities on Form 10. Accordingly, the Company is providing the information below that would be included in a Form 10 if the Company were to file a Form 10. Please note that the information provided below relates to the Company as the combined company after the consummation of the Merger, unless otherwise specifically indicated or the context otherwise requires.

The information set forth in Item 5.02 of this Current Report on Form 8-K under the heading “ Committees of the Board of Directors ” is incorporated herein by reference.

Legal Proceedings The information set forth in the section of the Proxy Statement/Prospectus entitled “ Korsana ’ s Business—Legal Proceedings ” on page 345 is incorporated herein by reference.

As of the Closing Date and following the completion of the Merger, and after giving effect to the Reverse Stock Split legally effected on September 8, 2026, the Company had approximately 45,541,425 shares of Company common stock issued and outstanding held of record by approximately 130 holders. The number of holders of record does not include a substantially greater number of “street name” holders or beneficial holders whose shares of Company common stock are held of record by banks, brokers and other financial institutions.

The information set forth in the section of the Proxy Statement/Prospectus entitled “ Market Price and Dividend Information—Dividends ” on page 32 is incorporated herein by reference.

You should read the following discussion of Korsana’s financial condition and results of operations in conjunction with the financial statements and the related notes thereto and other financial information included as Exhibit 99.2 to the Current Report on Form 8-K filed with the U.S. Securities and Exchange Commission (the “SEC”) on September 11, 2026 (the “Current Report on Form 8-K”) of which this is Exhibit 99.3 is a part, as well as our audited financial statements and the related notes thereto of Cyclerion’s Registration Statement on Form S-4 most recently amended on July 22, 2026 and declared effective on July 24, 2026 (the “Registration Statement”). The following discussion contains forward-looking statements that reflect our current plans, forecasts, estimates and beliefs and involve risks and uncertainties. Our historical results are not necessarily indicative of the results that may be expected for any period in the future.

Our actual results, outcomes and the timing of events could differ materially from those discussed in the forward-looking statements. Forward-looking statements are not historical facts, reflect our current views with respect to future events, and apply only as of the date made. We do not intend, and undertake no obligation, to update these forward-looking statements, except as required by law. References to “we,” “us,” “our,” “Korsana” or “the Company” refer to Korsana Biosciences, Inc. and its consolidated subsidiaries after the Merger, unless context otherwise requires.

The proprietary THETA technology used to create KRSA-028 combines the benefits of TfR-mediated shuttling to the brain with Fc modifications to extend half-life and spare reticulocytes from destruction shown to be caused by third-party TfR-shuttled investigational products. The THETA technology was designed to retain phagocytic capacity, the mechanism by which the two approved disease-modifying products are thought to clear amyloid plaques from the brain. Korsana believes that the THETA platform will lead to meaningful improvements in the ability to deliver therapeutic modalities, such as antibodies, to the brain, while minimizing the frequency of adverse events associated with other TfR-based shuttle systems. Korsana intends to expand its pipeline by advancing other product candidates that incorporate THETA technology. Korsana anticipates disclosing details on its next product candidate in late 2026 or 2027.

Since its inception in November 2024, Korsana has devoted substantially all of its resources to raising capital, organizing and staffing Korsana, business and scientific planning, conducting discovery and research activities, establishing arrangements with third parties, and providing general and administrative support for these operations. Korsana does not have any programs approved for sale and has not generated any revenue from product sales. To date, Korsana has funded its operations primarily with proceeds from the issuance of convertible preferred stock. In November 2024, Korsana received $10.0 million in gross proceeds from the issuance of Series A preferred stock, subsequently reclassified to Series Seed preferred stock in September 2025. Additionally in September 2025, Korsana received $15.0 million in gross proceeds from the issuance of Series Seed preferred stock and $151.0 million in gross proceeds from the issuance of Series A preferred stock to various investors.

advances its existing and future research and development and discovery-related development of its programs 001 and 002 (Aß and TfR1) (together the “Aß program”) and its undisclosed program 003;

seeks and identifies additional research programs and product candidates and initiates discovery- related activities and preclinical studies for those programs;