The main purpose of this study is to determine the effect of selpercatinib on the levels of dabigatran in the blood stream and how long it takes the body to remove dabigatran. This study will also look at how safe and well-tolerated of dabigatran when administered in combination with selpercatinib in healthy participants. This study will last approximately 22 to 25 days.

Inclusion Criteria:

• Overtly healthy males or females, as determined by medical history, physical examination and vital signs.
• Body mass index (BMI) within the range of 19 to 35 kilograms per meter squared (kg/m²)
• Male participants are not required to adhere to contraceptive requirements and female participants of childbearing potential must agree to be either remain abstinent or stay in a same sex relationship without sexual relationships with males or must agree to use a highly effective method of contraception and who underwent bilateral salpingectomy. The Female participants not of childbearing potential are not required to use contraception.

Exclusion Criteria:

• Have a positive pregnancy test at screening or Day -1, where applicable
• Are planning to become pregnant during the study or within 1 month of study completion
• Are women who are lactating
• Have known allergies to selpercatinib- or dabigatran-related compounds or any components of the formulation of selpercatinib or dabigatran, or history of significant atopy
• Have a history of allergic reactions to medications or food products
• Have a clinically significant abnormality of blood pressure and/or pulse rate as determined by the investigator
• Have known bleeding disorder including prior personal or familiar history of abnormal bleeding, hereditary or acquired coagulation or platelet disorder
• Clinically significant abnormalities on ECG as determined by the investigator or prolongation of the QTcB or QTcF >450 msec on more than 1 ECG obtained during screening only
• Have clinically significant active cardiovascular disease or history of myocardial infarction within 6 months prior to the planned start of selpercatinib
• Are currently enrolled in any other clinical study involving an investigational product or any other type of medical research judged not to be scientifically or medically compatible with this study
• Have an average weekly alcohol intake that exceeds 21 units per week (males ≤65 years old) and 14 units per week (females); 1 unit = 12 oz or 360 mL of beer; 5 oz or 150 mL of wine; 1.5 oz or 45 mL of distilled spirit(s)
• Are smokers of more than 10 cigarettes or e-cigarettes, or 3 cigars or 3 pipes, per day
• Consume excessive amounts of coffee, tea, cola, or other caffeinated beverages per day

All participants who received at least one dose of study drug.

Baseline up to 25 days

All participants who received at least one dose of study drug.