A Study With Intranasal Kinetic Oscillation Stimulation (KOS) in the Prevention of Chronic Migraine

Inclusion Criteria 1. The subject is legally competent, has been informed of the nature, the scope and the relevance of the study, voluntarily agrees to participation and the study's provisions, and has duly signed the informed consent form. 2. Male or female aged between 18 and 70 years (inclusive) at the time of providing informed consent. 3. Diagnosed as suffering from chronic migraine with or without aura (≥15 headache days per month including at least 8 migraine days for more than 3 months before screening) according to the International Headache Society classification (International Classification of Headache Disorders III); 4. Migraine onset before the age of 50 years. 5. Reported history of migraine for at least 1 year before screening. 6. If subjects are on a preventive treatment at the time of screening, this must have been stable over the preceding 3 months. 7. If subjects are on preventive treatment at the time of screening, they have to be able and willing to maintain current preventive treatment regimen (no change in type, frequency or dose) from screening to end of follow- 8. Failed at least 3 different preventive medications and 3 months of treatment with a CGRP targeting therapy. 9. Women of childbearing potential must be willing to use highly effective contraceptive methods (failure rate \<1% per year when used consistently and correctly) during the study. Exclusion Criteria 1. Unable to distinguish between migraine and other headache types. 2. An ongoing upper respiratory infection, nasal tumors, or wounds in the nasal cavity. 3. Nasal cavity abnormalities that prevents catheter insertion. 4. A concomitant condition that could cause excessive nose bleeding or ongoing treatment with anticoagulant medication (except Aspirin and Clopidogrel). 5. A known allergy to polyurethane (polyurethane is used in the catheter balloon). 6. Systemic diseases with manifestations in the nose. 7. Previous treatment with radiation therapy to the nasal area. 8. Nasal surgery performed within the last six months. 9. Concurrent condition or risk of non-compliance that, in the investigator's opinion, may affect the interpretation of performance or safety data or which otherwise contraindicates participation in a clinical investigation; 10. Pregnant and lactating women; 11. Participation in a clinical investigation within 3 months of enrolment or planned participation at any time during this clinical investigation; 12. Previous participation in this study; 13. Employees of the study site or the sponsor directly involved with the conduct of the study, or immediate family members of any such individuals;