Welcome to our dedicated page for Cyclerion Therapeutics SEC filings (Ticker: CYCN), a comprehensive resource for investors and traders seeking official regulatory documents including 10-K annual reports, 10-Q quarterly earnings, 8-K material events, and insider trading forms.
Cyclerion Therapeutics filings document material-event disclosures for a clinical-stage biopharmaceutical company developing neuropsychiatric therapeutics. Recent Form 8-K filings cover CYC-126 development updates, a clinical advisory board, and material agreements tied to technology for neuropsychiatric disorders and anesthetic delivery systems.
The company’s SEC records also describe its common stock listing under CYCN, shareholder voting results, director elections, auditor ratification, executive-compensation votes, governance matters, and exhibit-based press-release disclosures. The filings provide formal records of Cyclerion’s licensing arrangements, collaboration rights, capital structure, and transition from legacy sGC stimulator assets toward a neuropsychiatric pipeline.
Cyclerion Therapeutics, Inc. filed an Amendment No. 1 to Form S-4 proposing a merger with Korsana Biosciences pursuant to an Agreement and Plan of Merger and Reorganization amended April 17, 2026. The transaction contemplates an exchange of Korsana securities for Cyclerion common stock (estimated Exchange Ratio ~1.1009), a Korsana pre-closing financing of approximately $380.0 million, and post-closing ownership in which former Korsana holders are expected to hold approximately 98.5% of the Combined Company on a fully-diluted basis (Cyclerion holders ~1.5%), subject to adjustments including Cyclerion net cash at closing and a proposed reverse stock split.
The merger contemplates conversion of options, RSUs, warrants and preferred stock into corresponding Cyclerion instruments or cash in specified circumstances, a Contingent Value Right program for certain Cyclerion legacy assets, and requested shareholder votes on proposals including an authorized share increase, reverse stock split, redomestication to the Cayman Islands, and approval of issuance under Nasdaq rules. The Merger closing is conditioned on customary items including Nasdaq confirmation of listing for the Combined Company and required shareholder approvals.
Cyclerion Therapeutics reported a first-quarter 2026 net loss of $3.2M, wider than the prior year, on no revenue as operating expenses rose to $3.2M. Cash and cash equivalents were $2.8M against total assets of $8.5M, and management disclosed substantial doubt about the company’s ability to continue as a going concern beyond the third quarter of 2026 without additional funding.
The company has agreed to merge with privately held Korsana Biosciences, after which Korsana’s neurodegenerative disease programs will become the primary business and Cyclerion will be renamed Korsana Biosciences, Inc. A concurrent Korsana financing of approximately $380.0M and a Contingent Value Rights Agreement are intended to capture potential value from Cyclerion’s legacy assets for current shareholders.
Cyclerion Therapeutics Inc ownership filing shows FMR LLC beneficially owns 649,547 shares of common stock, representing 15.0% of the class as of 04/30/2026. The filing states portions of that interest are held on behalf of Fidelity Growth Company Commingled Pool (287,563 shares, 6.6%) and Fidelity Growth Company Fund (218,257 shares, 5.0%). The schedule is a passive institutional disclosure listing voting and dispositive powers and refers to an attached exhibit and a power of attorney.
Cyclerion Therapeutics filed an amended annual report mainly to add Part III disclosures on board structure, executive pay and share ownership. The company highlights an independent chairman, three key board committees, and policies covering risk oversight, insider trading and clawbacks. It reports that as of March 26, 2026 there were 4,330,314 common shares outstanding, with directors and officers as a group beneficially owning 26.6%. The filing details 2025 compensation for CEO Regina Graul and CFO Rhonda Chicko, including salary, cash bonuses and stock-based awards, and summarizes equity incentive and employee stock purchase plans. It also describes a March 2025 private placement raising $1.375 million and notes a previously announced proposed merger with Korsana Biosciences expected to close in the third quarter of 2026, subject to shareholder approvals and other conditions.
Cyclerion Therapeutics, Inc. is filing a Form S-4 to register securities in connection with a proposed merger with Korsana Biosciences, Inc., pursuant to an Agreement and Plan of Merger and Reorganization amended on April 17, 2026. The transaction contemplates exchanging Korsana securities for Cyclerion common stock (an estimated Exchange Ratio of approximately 1.1009 based on certain capitalization assumptions) and related instruments, and includes a Korsana pre-closing financing of approximately $380.0 million. Immediately after the Merger, Cyclerion holders are expected to own about 1.5% of the Combined Company (fully diluted) and former Korsana holders about 98.5%, subject to adjustments including Cyclerion Net Cash at closing and shareholder approvals. The Merger is conditioned on shareholder approvals, Nasdaq listing confirmation, and customary closing conditions; completion is anticipated in Q3 2026.
Cyclerion Therapeutics entered into a definitive Merger Agreement to combine with Korsana Biosciences. The transaction contemplates a two-step merger structure intended to qualify as a tax-free reorganization under Section 368(a). Concurrently, investors agreed to a Private Placement for approximately $380M to fund the combined company. On a pro forma basis (and prior to the described financing), pre-Merger Korsana stockholders are expected to own approximately 1.5% of the combined company and pre-Merger Cyclerion shareholders approximately 98.5%. The deal includes a Beneficial Ownership Limitation (initially up to 14.99%) and use of pre-funded warrants for excess shares, creation of a non-voting Series B Preferred Stock convertible into 1,000 shares of Cyclerion common stock with a conversion cap of 19.99%, a Contingent Value Right plan for pre-Merger Cyclerion shareholders, and customary closing conditions including shareholder approvals, Nasdaq listing approval, HSR clearance and receipt of not less than $150,000,000 under a securities purchase agreement. The transaction was approved by both Boards and is expected to close in Q3 2026, subject to the stated conditions. Cyclerion amended the CEO offer letter to provide a change-of-control bonus of up to $150,000, nine months’ severance, accelerated vesting on certain terminations and health premium contributions for 12 months.
Cyclerion Therapeutics agreed to merge with privately held Korsana Biosciences in an all‑stock transaction that effectively hands control to Korsana. Based on the agreed exchange ratio and before the large financing, pre‑merger Korsana stockholders are expected to own approximately 98.5% of the combined company, with pre‑merger Cyclerion shareholders owning about 1.5%.
Concurrently, Korsana investors committed approximately $380 million in a private placement expected to fund operations into 2029 and support development of lead Alzheimer’s candidate KRSA‑028. Cyclerion shareholders will also receive contingent value rights tied to future monetization of legacy assets, while the company plans to rename itself Korsana Biosciences, implement a reverse stock split, create new Series B non‑voting convertible preferred stock and reconstitute the board under Korsana’s leadership.
Cyclerion Therapeutics outlines a major strategic shift toward developing CYC-126, an anesthetic-based, technology-enabled treatment for treatment-resistant depression (TRD), while monetizing legacy soluble guanylate cyclase (sGC) assets through licensing and its equity stake in Tisento Therapeutics.
The company signed a license with MIT for TRD-related IP with up to $4.4 million in milestones and a collaboration and option-to-license agreement with Medsteer SAS with up to $3.7 million in milestones, plus low single-digit royalties to both partners. CYC-126 is planned to enter a Phase 2 proof-of-concept trial in Australia in the second half of 2026, with U.S. enrollment expected in the first half of 2027.
Cyclerion continues to benefit from its praliciguat out-license to Akebia, having received a $1.0 million Phase 2 initiation milestone in 2026 and being eligible for up to approximately $557.5 million in future milestones and tiered mid-single-digit to twenty percent royalties. However, the company reported a net loss of $3.5 million in 2025, ended the year with $3.2 million in cash and cash equivalents, and explicitly states there is substantial doubt about its ability to continue as a going concern without near-term capital raises.
Cyclerion Therapeutics reported progress on CYC-126, its lead neuropsychiatric therapy for treatment-resistant depression. The company received positive written feedback from the FDA on the design of a Phase 2 proof-of-concept study and the overall regulatory pathway, helping support its planned IND submission.
The planned trial is a randomized, double-blind, two-part study in adults with treatment-resistant depression, using FDA-accepted endpoints such as the MADRS scale. Cyclerion aims to start the Phase 2 study in the second half of 2026, with first patients in Australia and U.S. enrollment beginning in the first half of 2027.
The company also formed a five-member Clinical Advisory Board of leaders in neuropsychiatry, anesthesiology, and clinical development to guide CYC-126 and broader pipeline strategy. The press release reiterates forward-looking risks, including regulatory uncertainty, funding needs, and substantial doubt about the company’s ability to continue as a going concern referenced in prior filings.
Cyclerion Therapeutics entered into a Collaboration and Option Agreement with Medsteer, SAS. Medsteer granted Cyclerion a non-exclusive, worldwide, royalty-free license to use certain Medsteer technology and software to jointly develop an anesthetic delivery system, and also granted Cyclerion an exclusive option to obtain a worldwide, royalty-bearing license to develop or commercialize related products in the defined Company Field.
The option may be exercised at Cyclerion’s discretion during an initial two-year period, which can be extended by an additional two years upon payment of a nominal fee or by mutual agreement. Medsteer is eligible for up to $3.7 million in development, regulatory and sales milestone payments, plus annual and low single-digit percentage royalties on future net sales. Cyclerion and Medsteer will jointly own know-how from the collaboration, and Cyclerion receives a right of first negotiation on transactions involving that know-how. The company also issued a press release and investor presentation updating progress on CYC-126, its lead product candidate.