Atrial fibrillation is when the heart's two upper chambers (called atria) beat chaotically and irregularly, out of coordination with the two lower chambers (called ventricles) of the heart. This can lead to blood clots forming in the heart chamber.

Patients with atrial fibrillation will be treated with either 60 mg or 75 mg of edoxaban for up to 12 months, with a 2-4 week follow-up, after which their participation is complete.

Blood samples will be collected before the first dose of study drug (Day 0), and on Days 30, 90 and 360 (at pre dose, 1-2 hours post dose and 4-8 hours post-dose).

Inclusion Criteria:

• Meets protocol-specified criteria for qualification
• Is able to follow the protocol specified contraception methods
• Is willing and able to comply with any restrictions related to food, drink and medications
• Voluntarily consents to participate and provides written informed consent prior to any protocol-specific procedures

Exclusion Criteria:

• Has history or current use of over-the-counter medications, dietary supplements, or drugs (including nicotine and alcohol) outside protocol-specified parameters

• Has signs, symptoms or history of any condition that, per protocol or in the opinion of the investigator, might compromise:

  1. the safety or well-being of the participant or study staff
  2. the safety or well-being of the participant's offspring (such as through pregnancy or breast-feeding)
  3. the analysis of results

De-identified individual participant data (IPD) and applicable supporting clinical trial documents may be available upon request at https://vivli.org/. In cases where clinical trial data and supporting documents are provided pursuant to our company policies and procedures, Daiichi Sankyo will continue to protect the privacy of our clinical trial participants. Details on data sharing criteria and the procedure for requesting access can be found at this web address: https://vivli.org/ourmember/daiichi-sankyo/

Studies for which the medicine and indication have received European Union (EU) and United States (US), and/or Japan (JP) marketing approval on or after 01 January 2014 or by the US or EU or JP Health Authorities when regulatory submissions in all regions are not planned and after the primary study results have been accepted for publication.

Formal request from qualified scientific and medical researchers on IPD and clinical study documents from clinical trials supporting products submitted and licensed in the United States, the European Union and/or Japan from 01 January 2014 and beyond for the purpose of conducting legitimate research. This must be consistent with the principle of safeguarding study participants' privacy and consistent with provision of informed consent.