Cyclerion Therapeutics and Korsana Biosciences Announce Merger Agreement (Form 8-K)

Cyclerion Therapeutics and Korsana Biosciences Announce Merger Agreement

Combined company to operate as Korsana Biosciences and to advance Korsana's potential best-in-class therapeutics to treat neurodegenerative diseases

Korsana's lead program KRSA-028 is a next-generation shuttled monoclonal antibody targeting amyloid beta for the treatment of Alzheimer's disease

Concurrent private financing of approximately $380 million expected to fund Korsana's operations into

2029, including multiple clinical trial data readouts expected in 2027

Conference call scheduled for April 1, 2026, at 8:00 am ET

WALTHAM, Mass., April 1, 2026- Cyclerion Therapeutics, Inc. ("Cyclerion") (Nasdaq: CYCN) and Korsana Biosciences, Inc. ("Korsana"), a privately-held biotechnology company discovering and developing novel therapies to reduce the burden of neurodegenerative diseases, today announced that they have entered into a definitive merger agreement for an all-stock transaction. Upon completion of the transaction, the combined company plans to operate under the name Korsana Biosciences, Inc. and trade on Nasdaq under the ticker symbol "KRSA."

In support of the proposed merger, Korsana has secured commitments for an oversubscribed private investment that is expected to result in total gross proceeds of approximately $380 million from a syndicate of investors led by Fairmount and Venrock Healthcare Capital Partners, with participation from General Atlantic, TCGX, Forbion, Wellington Management, Commodore Capital, RA Capital Management, RTW Investments, Vivo Capital, Janus Henderson Investors, Foresite Capital, J.P. Morgan Life Sciences Private Capital, SR One, Sanofi Ventures, Kalehua Capital, Spruce Street Capital, and other leading investment management firms. The financing includes common stock and pre-funded warrants exercisable for shares of Korsana common stock.

The financing is expected to close immediately prior to completion of the proposed merger. The combined company's cash and cash equivalents balance at closing, including the funds from the private placement, is anticipated to fund Korsana's operations into 2029 and provides runway through key clinical milestones. These include the advancement of KRSA-028 through Phase 1 healthy volunteer data expected in mid-2027 and interim proof of concept data measuring amyloid plaque clearance in Alzheimer's patients expected by the end of 2027.

"Korsana is determined to deliver breakthrough medicines for patients suffering from neurodegenerative disorders. With our seasoned team and support from leading biotechnology investors, Korsana is well-positioned to advance a pipeline of innovative, next generation therapies," said Jonathan Violin, Ph.D., Korsana's President and Chief Executive Officer. "Patients deserve better options than what is currently available, and we believe our lead program KRSA-028 can deliver a best-in-class product to treat Alzheimer's disease. We are also building a broader pipeline leveraging our proprietary platform to target other devastating neurodegenerative disorders."

Korsana is the seventh company to launch with assets discovered and developed by Paragon Therapeutics. Korsana's lead program is KRSA-028, a next-generation shuttled antibody targeting amyloid beta for the treatment of Alzheimer's disease, discovered in partnership with Paragon Therapeutics. KRSA-028 utilizes the proprietary Therapeutic Targeting (THETA^™) platform, which incorporates clinically validated transferrin receptor (TfR1) and Fc engineering and is designed to improve brain delivery and solve limitations of other TfR1-based approaches. KRSA-028 was designed to increase amyloid plaque clearance, reduce the rate of amyloid-related imaging abnormalities (ARIA) and hematologic adverse events, and optimize convenience and compliance with a low-volume subcutaneous route of administration. Korsana is advancing a pipeline of innovative THETA-enabled therapies for other undisclosed, neurodegenerative diseases with high unmet need.

"Our transaction with Korsana is the result of a comprehensive strategic review, and we believe it represents the best path forward for Cyclerion," said Regina Graul, Ph.D., President and Chief Executive Officer of Cyclerion. "Korsana's promising and innovative pipeline targeting neurodegenerative disorders, beginning with Alzheimer's disease, provides the potential for significant value creation for Cyclerion's shareholders."

About the Proposed Transactions

Under the terms of the merger agreement, as of the closing of the proposed merger, the pre-merger Cyclerion shareholders are expected to own approximately 1.5% of the combined company and the pre-merger Korsana stockholders (inclusive of those investors participating in the pre-closing financing) are expected to own approximately 98.5% of the combined company. The percentage of the combined company that Cyclerion's shareholders will own as of the closing of the proposed merger is subject to adjustment based on the estimated amount of Cyclerion's net cash immediately prior to the closing date.

The transaction has received approval by the Board of Directors of both companies and is expected to close in the third quarter of 2026, subject to certain closing conditions, including, among others, approval by the stockholders of each company, the effectiveness of a registration statement to be filed with the U.S. Securities and Exchange Commission (the "SEC") to register the securities to be issued in connection with the proposed merger, expiration of the waiting period under the Hart-Scott-Rodino Antitrust Improvements Act of 1976, as amended, and the satisfaction of other customary closing conditions.

The combined company plans to operate under the name Korsana Biosciences, Inc. and will be led by Dr. Violin, Korsana's current Chief Executive Officer. Korsana's existing Board of Directors will become directors of the combined company, chaired by Tomas Kiselak, Founding Partner at Fairmount, and including Andrew Gottesdiener, M.D., Partner at Venrock Healthcare Capital Partners, Nilesh Kumar, Ph.D., Head of Biotech Private Investments at Wellington Management, Michelle Pernice, Operating Partner at Fairmount, Nimish Shah, Partner at Venrock Healthcare Capital Partners, and Dr. Violin.

Wedbush Securities Inc. is serving as exclusive strategic financial advisor and Gibson, Dunn & Crutcher LLP is serving as legal counsel to Korsana. Jefferies, TD Cowen, Stifel, UBS Investment Bank, and Wedbush & Co., LLC are serving as the placement agents to Korsana. Cooley LLP is serving as legal counsel to the placement agents. Gemini Valuation Services, LLC is serving as financial advisor and Ropes & Gray LLP is serving as legal counsel to Cyclerion.

Conference Call Details

The companies will hold a joint conference call on April 1, 2026, at 8:00 am ET to discuss the details of the proposed transactions.

Please access the presentation by clicking on the following link: https://register-conf.media-server.com/register/BIdbeaaec6359f483ab6e6685bd93e6312

About KRSA-028

KRSA-028 is an investigational, shuttled antibody targeting amyloid beta designed to advance the future of Alzheimer's treatment. KRSA-028 utilizes a proven mechanism of action, selectively binding forms of amyloid beta that are enriched in amyloid plaques. KRSA-028 leverages Korsana's Therapeutic Targeting (THETA^™) technology, which incorporates clinically validated transferrin receptor (TfR1) and Fc engineering and is designed to improve brain delivery, safety, and convenience.

About Cyclerion Therapeutics

Cyclerion is a biopharmaceutical company focused on developing treatments for neuropsychiatric diseases. Cyclerion's foundational product candidate, CYC-126, is an individualized therapy for treatment-resistant depression, a condition with significant unmet medical need and substantial commercial opportunity.

For more information about Cyclerion, please visit https://www.cyclerion.com/ and follow us on X (@Cyclerion) and LinkedIn (www.linkedin.com/company/cyclerion).

About Korsana Biosciences

Korsana Biosciences was founded to reduce the burden of neurodegenerative diseases for patients and caregivers. Developed in partnership with Paragon Therapeutics, Therapeutic Targeting (THETA^™) is a novel blood-brain barrier-penetrant shuttle platform designed to enable dramatically higher drug concentration inside the brain and overcome the limitations of earlier shuttle technologies. Korsana is advancing a pipeline of innovative THETA-enabled therapies for neurodegenerative diseases, starting with KRSA-028 for the treatment of Alzheimer's disease. For more information, please visit www.korsana.com.