License and Option Agreement	12 Months Ended
Dec. 31, 2024
License Agreement [Abstract]
License and Option Agreement	15. License and Option Agreement Option Agreement On July 22, 2024, the Company entered into an Option to License Agreement (the “Option Agreement”) with a third party (the “Optionee”), pursuant to which the optionee has an option (the “Option”), to enter into an exclusive license to olinciguat for human therapeutics, subject to certain carveouts. Under the terms of the Option Agreement, the Optionee paid the Company an Option fee of $150,000 in August 2024. The Optionee may exercise the Option on or before March 20, 2025, which may be extended for an additional two-month period for an additional fee of $25,000. If the Optionee exercises the Option during the Option Period, the Parties shall promptly commence negotiations of the definitive license agreement. The terms of the license agreement will be negotiated in good faith within a period not to exceed 90 days after the date of exercise of the Option. If the parties cannot reach agreement, all rights revert to the Company. In addition, the Optionee has agreed to reimburse the Company for certain patent expenses incurred during the Option period. The Company recognized revenue of $0.2 million related to the Option fee payment and expense reimbursement for the year ended December 31, 2024. Akebia License Agreement On June 3, 2021, the Company and Akebia entered into a License Agreement (the “Akebia License Agreement”) relating to the exclusive worldwide license by the Company to Akebia of our rights to the development, manufacture, medical affairs and commercialization of pharmaceutical products containing the pharmaceutical compound known as praliciguat and other related products and forms thereof enumerated in the License Agreement (collectively, the “Products”). Pursuant to the Akebia License Agreement, Akebia will be responsible for all future research, development, regulatory, and commercialization activities for the Products. Akebia paid a $3.0 million up-front payment to the Company upon signing of the License Agreement. On December 13, 2024, the Company and Akebia entered into Amendment #1 to License Agreement (the “Amendment”) to the original License Agreement between the parties dated June 3, 2021 (the “2021 License Agreement”). Under the terms of the Amendment, Akebia paid the Company $1.25 million in December 2024 and is obligated to pay an additional $0.5 million on or before September 30, 2025. In addition, Akebia has agreed to assume control of the preparation, filing, prosecution and maintenance of certain Cyclerion patents, and the expenses associated therewith, at an earlier date than as originally agreed between the parties. The parties have agreed to the reduction of certain development milestones and the increase of certain royalty rates on net sales and sublicense income. Pursuant to the terms of the 2021 License Agreement, as amended, Cyclerion is eligible to receive up to $558.5 million in total potential future development, regulatory, and commercialization milestone payments, and Akebia will pay Cyclerion tiered royalties ranging from mid-single digit to twenty percent of net sales. Cyclerion’s obligations to deliver certain drug products have also ceased. Pursuant to the Akebia License Agreement, the Company determined the Akebia License Agreement represents a service arrangement under the scope of ASC 606. Given the reversion of the rights under the Akebia License Agreement represents a penalty in substance for a termination by Akebia, the contract term would be the stated term of the License Agreement. The Company determined that the grant of license to its patents and trademarks, know how transfer, the assignment of regulatory submissions and trademarks and additional knowledge transfer assistance obligations represent a single promise and performance obligation to be transferred to Akebia over time due to the nature of the promises in the contract. The provision of development materials on hand was identified as a separate performance obligation. However, it is immaterial in the context of the contract as the development materials are low value and do not have an alternative use to the Company. The consideration related to sales-based milestone payments, including royalties, will be recognized when the related sales occur as these amounts have been determined to relate predominantly to the license. The Company will re-evaluate the probability of achievement of the milestones and any related constraints each reporting period.

License and Option Agreement

12 Months Ended

Dec. 31, 2024

15. License and Option Agreement

Option Agreement

On July 22, 2024, the Company entered into an Option to License Agreement (the “Option Agreement”) with a third party (the “Optionee”), pursuant to which the optionee has an option (the “Option”), to enter into an exclusive license to olinciguat for human therapeutics, subject to certain carveouts. Under the terms of the Option Agreement, the Optionee paid the Company an Option fee of $150,000 in August 2024. The Optionee may exercise the Option on or before March 20, 2025, which may be extended for an additional two-month period for an additional fee of $25,000. If the Optionee exercises the Option during the Option Period, the Parties shall promptly commence negotiations of the definitive license agreement. The terms of the license agreement will be negotiated in good faith within a period not to exceed 90 days after the date of exercise of the Option. If the parties cannot reach agreement, all rights revert to the Company. In addition, the Optionee has agreed to reimburse the Company for certain patent expenses incurred during the Option period. The Company recognized revenue of $0.2 million related to the Option fee payment and expense reimbursement for the year ended December 31, 2024.

Akebia License Agreement

On June 3, 2021, the Company and Akebia entered into a License Agreement (the “Akebia License Agreement”) relating to the exclusive worldwide license by the Company to Akebia of our rights to the development, manufacture, medical affairs and commercialization of pharmaceutical products containing the pharmaceutical compound known as praliciguat and other related products and forms thereof enumerated in the License Agreement (collectively, the “Products”). Pursuant to the Akebia License Agreement, Akebia will be responsible for all future research, development, regulatory, and commercialization activities for the Products.

Akebia paid a $3.0 million up-front payment to the Company upon signing of the License Agreement. On December 13, 2024, the Company and Akebia entered into Amendment #1 to License Agreement (the “Amendment”) to the original License Agreement between the parties dated June 3, 2021 (the “2021 License Agreement”).

Under the terms of the Amendment, Akebia paid the Company $1.25 million in December 2024 and is obligated to pay an additional $0.5 million on or before September 30, 2025. In addition, Akebia has agreed to assume control of the preparation, filing, prosecution and maintenance of certain Cyclerion patents, and the expenses associated therewith, at an earlier date than as originally agreed between the parties. The parties have agreed to the reduction of certain development milestones and the increase of certain royalty rates on net sales and sublicense income. Pursuant to the terms of the 2021 License Agreement, as amended, Cyclerion is eligible to receive up to $558.5 million in total potential future development, regulatory, and commercialization milestone payments, and Akebia will pay Cyclerion tiered royalties ranging from mid-single digit to twenty percent of net sales. Cyclerion’s obligations to deliver certain drug products have also ceased.

Pursuant to the Akebia License Agreement, the Company determined the Akebia License Agreement represents a service arrangement under the scope of ASC 606. Given the reversion of the rights under the Akebia License Agreement represents a penalty in substance for a termination by Akebia, the contract term would be the stated term of the License Agreement.

The Company determined that the grant of license to its patents and trademarks, know how transfer, the assignment of regulatory submissions and trademarks and additional knowledge transfer assistance obligations represent a single promise and performance obligation to be transferred to Akebia over time due to the nature of the promises in the contract. The provision of development materials on hand was identified as a separate performance

obligation. However, it is immaterial in the context of the contract as the development materials are low value and do not have an alternative use to the Company.

The consideration related to sales-based milestone payments, including royalties, will be recognized when the related sales occur as these amounts have been determined to relate predominantly to the license. The Company will re-evaluate the probability of achievement of the milestones and any related constraints each reporting period.