Safety, Tolerability, Pharmacokinetics and Pharmacodynamics of TAK-438 in Healthy Male Participants

The purpose of this study was to evaluate the safety and pharmacokinetics of TAK-438 following multiple oral doses to healthy adult Japanese male participants

The drug being tested in this study is called TAK-438. TAK-438 was being tested to assess side effects and how TAK-438 moves throughout the body after multiple doses have been administered. This study looked at lab results and side effects in people who took TAK-438.

The study consisted of 5 steps covering dose ranges of TAK-438 from 10, 15, 20, 30 and 40 mg once daily for 7 days. The study population for each step included 12 participants. Within each step, 9 participants were randomized to TAK-438 and 3 participants were randomized to placebo. A total of 60 participants were enrolled.

The dosing groups in this study took place in sequential order. Therefore, the TAK-438 15 mg group did not start until the TAK-439 10 mg group had completed, etc. All participants in each dosing group were asked to take the study drug in the morning, after fasting for at least 10 hours, each day throughout the study.

This single-centre trial was conducted in the Japan. The overall time to participate in this study was up to 43 days. Participants made 3 visits to the clinic, including one 11-day period of confinement to the clinic, and a final visit 7 days after last dose of study drug for a follow-up assessment.

Eligibility Criteria:
Inclusion Criteria:

1. Healthy adult Japanese male volunteer.
2. Is 20-45 years old inclusive, at time of giving consent.
3. Is capable of understanding and complying with protocol requirements.
4. Signs a written, informed consent form prior to the initiation of any study procedure.
5. Weighs at least 50 kg and has a body mass index (BMI) of 18.5 to 25.0 kg/m\^2 inclusive at screening.
6. Tests negative for hepatitis B surface antigen (HBs), hepatitis C virus (HCV) antibody, human immunodeficiency virus (HIV) antigen-antibody and syphilis serum reaction test.
7. The participant who the investigator or subinvestigator confirmed to be eligible to participate in this study based on results of the screening tests, and physical examination, physical findings, vital signs, electrocardiogram (ECG), clinical laboratory tests etc. from 3 days before dosing to before the start of dosing on Day 1 with the study drug.

Exclusion Criteria:

1. Has undergone upper gastrointestinal resectioning or vagetomy.
2. Is judged to have hypoacidity or anacidity.
3. Presently has or a history of acid-related diseases (e.g., erosive esophagitis, duodenal ulcer, gastric ulcer, non-erosive esophagitis, Barrett's esophagitis or Zollinger-Ellison syndrome).
4. Received H. pylori eradication treatment within 6 months prior to the start of treatment with the study drug.
5. Presently has or has a history of hepatic disorder, renal disorder, cardiovascular system disease, blood disease, endocrine disease, metabolic disease, lung disease, gastrointestinal disease, nervous system disease, urological disease, immunological disease or mental illness that makes him not eligible to participate in this study.
6. Presently has or has a history of hypersensitivity or allergy towards drugs or food.
7. Has a history of drug abuse (defined as any illicit drug use) or a history of alcohol abuse within 5 years prior to the start of treatment with the study drug.
8. Participant for whom it is difficult to collect blood from the peripheral veins.
9. Has donated more than 200 mL of whole blood within 4 weeks (28 days) or more than 400 mL of whole blood within 12 weeks (84 days) prior to the start of treatment with the study drug.
10. Has donated a total volume of more than 800 mL of whole blood within 52 weeks (364 days) prior to the start of treatment with the study drug.
11. Has given plasma component and plaque component within 2 weeks (14 days) prior to the start of treatment with the study drug.
12. Has used a prescription drug (including over-the counter drugs) within 4 weeks (28 days) prior to the start of treatment with the study drug.
13. Has used vitamins, Chinese herbal remedies, or supplement (including St John's Wort, ginseng, kava kava, ginkgo biloba, melatonin) within 4 weeks (28 days) prior to the start of treatment with the study drug.
14. Has ingested any foods or beverages containing grapefruit (juice or pulp), caffeine, alcohol within 72 hours prior to the start of treatment with the study drug.
15. Administered another study drug within 16 weeks (112 days) prior to the start of treatment with this study drug.
16. Administered TAK-438 in the past.
17. Is considered by the investigator or subinvestigator, for any reason, to be an unsuitable candidate for participating in this study