The study has 2 Parts: The primary purpose of Part 1 is to determine the supratherapeutic dose of brensocatib to be used in Part 2 of the study.

The primary purpose of Part 2 is to assess brensocatib's potential for prolonging the QT interval.

Inclusion Criteria:

1. Body mass index (BMI) between 18.0 and 32.0 kilogram per square metre (kg/m^2), inclusive, and a total body weight greater than or equal to 50 kilograms (kg)
2. Females will not be pregnant or lactating, and females of childbearing potential and males will agree to use contraception
3. Able to comprehend and willing to sign an informed consent form (ICF) and to abide by the study restrictions
4. Able to swallow tablets

Exclusion Criteria:

1. History of significant hypersensitivity, intolerance, or allergy to any drug compound, food, or other substance, unless approved by the investigator (or designee)
2. History of stomach or intestinal surgery or resection that would potentially alter absorption and/or excretion of orally administered drugs
3. QTcF interval >430 ms for males and >440 ms for females or QRS >120 ms
4. A history of additional risk factors for torsade de pointes (eg, heart failure, hypokalemia, or family history of long QT syndrome)
5. Positive serology test results for hepatitis B panel and hepatitis C antibody and/or reactive human immunodeficiency virus 1/2 test
6. Administration of a coronavirus disease 2019 (COVID-19) vaccine in the past 14 days prior to dosing
7. Use or intend to use any medications/products known to alter drug absorption, metabolism, or elimination processes, including St. John's wort, within 30 days prior to dosing, unless deemed acceptable by the investigator (or designee)
8. Use or intend to use any prescription medications/products within 14 days prior to dosing, unless deemed acceptable by the investigator (or designee)
9. Use or intend to use slow-release medications/products considered to still be active within 14 days prior to check-in, unless deemed acceptable by the investigator (or designee)
10. Use or intend to use any nonprescription medications/products including vitamins, minerals, and phytotherapeutic/herbal/plant-derived preparations within 7 days prior to check-in, unless deemed acceptable by the investigator (or designee)
11. Use or intend to use any medications that may increase QT interval within 14 days prior to check-in
12. Participation in a clinical study involving administration of an investigational drug (new chemical entity) in the past 30 days prior to dosing
13. Have previously completed or withdrawn from this study or any other study investigating brensocatib, and have previously received brensocatib
14. Alcohol consumption of >14 units per week for males and >7 units for females. One unit of alcohol equals 12 ounce (oz) (360 milliliter [mL]) beer, 1½ oz (45 mL) liquor, or 5 oz (150 mL) wine
15. Consumption of caffeine-containing products within 48 hours prior to check-in, unless deemed acceptable by the investigator (or designee)
16. History of chemical abuse, illicit substance, or marijuana use within 1 year prior to check-in
17. Use of tobacco- or nicotine-containing products within 3 months prior to check-in
18. Receipt of blood products within 2 months prior to check-in
19. Donation of blood from 3 months prior to screening, plasma from 2 weeks prior to screening, or platelets from 6 weeks prior to screening
20. Poor peripheral venous access