Cyclerion Therapeutics Inc. is a clinical-stage biopharmaceutical company headquartered in Cambridge, Massachusetts, focused on discovering, developing, and commercializing innovative human therapeutics. The company specializes in soluble guanylate cyclase stimulators, small molecules that work synergistically with nitric oxide to enhance cyclic guanosine monophosphate production. Cyclerion's lead program combines validated therapeutic modes of action with a personalized, tech-enabled delivery system targeting neuropsychiatric diseases. The company's foundational product candidate is CYC-126, an individualized therapy designed for treatment-resistant depression, a condition with significant unmet medical need. Cyclerion leverages well-characterized pharmacological approaches paired with biofeedback-driven technology to address complex neurological conditions and advance precision medicine in mental health treatment.