A Study of TAK-951 in Healthy Adults
Condition: Healthy Volunteer
Intervention: TAK-951; TAK-951 Placebo
Intervention description: TAK-951 intravenous infusion.; TAK-951 placebo-matching intravenous infusion.
Phase: Phase 1
Study type: Interventional
Primary purpose: Other
Allocation: Randomized
Intervention model: Sequential Assignment
Masking: Quadruple (Participant, Care Provider, Investigator, Outcomes Assessor)
Enrollment: 32.0
Sex: All
Minimum age: 19 Years
Maximum age: 55 Years
Healthy volunteers: Accepts Healthy Volunteers
Keywords: Drug Therapy

Summary:

      It is hoped that a medicine called TAK-951 will eventually be used to treat nausea and
      vomiting. Before then, the sponsor needs to understand how the body processes TAK-951 in
      healthy adults.

      The main aims of this study are as follows:

        -  To check for side effects from TAK-951 when given at a slow and fast infusion rate.

        -  To learn how much TAK-951 participants can receive without getting side effects from it.

      Participants will receive a single infusion of either TAK-951 or placebo. In this study, a
      placebo looks like TAK-951 but does not have any medicine in it. Participants will receive
      either a low dose or high dose of TAK-951. The infusion will take from 1-3 hours.

      Participants will stay in the study clinic for about 4 days to receive the study medicine
      (TAK-951 or placebo) and check for side effects. They will have follow-up visits at the
      clinic about 2 weeks and 4 weeks after treatment.
    

Eligibility criteria:

        Inclusion Criteria:

          1. Continuous non-smoker who has not used nicotine- and tobacco-containing products
             and/or cannabis products for at least 3 months prior to dosing and throughout the
             study.

          2. Body mass index (BMI) greater than or equal to (>=) 18.0 and less than or equal to
             (<=) 32.0 kilogram per square meter (kg/m^2) at screening.

          3. Female must be of non-childbearing potential.

        Exclusion Criteria:

          1. Is mentally or legally incapacitated or has significant emotional problems at the time
             of the screening visit or expected during the conduct of the study.

          2. Drink alcohol in excess of 21 glasses/units per week for males or 14 glasses/units per
             week for females, with one unit equal to (=) 150 milliliter (mL) of wine or 360 mL of
             beer or 45 mL of 45 percent (%) alcohol.

          3. Have any tattoos, scars or skin issue at planned IV infusion site which could
             interfere with dosing.

          4. History or presence of:

               -  Three (3) or more incidences of vasovagal syncope within the last 5 years prior
                  to screening.

               -  Family history of unexplained sudden death or channelopathy.

               -  Brugada syndrome (that is, right bundle branch block (RBBB) pattern with
                  ST-elevation in leads V1-V3).

               -  Cardiovascular or cerebrovascular disease, such as cardiac valvulopathy,
                  myocardial infarction, stroke, sick sinus syndrome, pulmonary congestion,
                  symptomatic or significant cardiac arrhythmia, second-degree AV block type 2,
                  third-degree AV block, prolonged corrected QT interval by Fredericia (QTcF)
                  interval, hypokalemia, hypomagnesemia, or conduction abnormalities;

               -  Risk factors for Torsade de Pointes (example, heart failure, cardiomyopathy, or
                  family history of Long QT Syndrome);

               -  Any clinically significant ECG findings or medical history including: long or
                  short QT interval with QTcF (over 450 msec or less than 360 msec), bifascicular
                  block or QRS >=120 msec or PR interval greater than (>) 200 msec at screening or
                  Day -1 pre-Hour 0.

               -  Documented history of sinoatrial block or sinus pause >=3 seconds.

          5. Semi-recumbent blood pressure (average of duplicate) is less than 90/60 millimeter of
             mercury (mmHg) or greater than 140/90 mmHg at screening.

          6. Has an average semi-recumbent heart rate <60 or >100 beats per minute (bpm) (at
             screening, at Day -1 pre-Hour 0, or at pre-dose Day 1); athletic participants with an
             average semi-recumbent heart rate <60 bpm can be enrolled only with medical monitor
             approval. If participant has heart rate <60 bpm Investigator should obtain medical
             approval from Sponsor.

          7. Has orthostatic hypotension defined as a decrease in systolic blood pressure >=20 mmHg
             or a decrease in diastolic blood pressure >=10 mmHg after 2 minutes of standing when
             compared with blood pressure from the semi-recumbent position at screening and at Day
             -1 pre-Hour 0. The semi-recumbent blood pressure will be an average of duplicate
             measurements.

          8. Has postural orthostatic tachycardia, defined as an increase of 30 bpm or heart rate
             >120 bpm after standing for 2 minutes.

          9. Positive urine drug or alcohol results at screening or check-in.

         10. Positive urine cotinine at screening or check-in.

         11. Positive results at screening for human immunodeficiency virus (HIV), hepatitis B
             surface antigen (HBsAg), or hepatitis C virus (HCV).

         12. Unable to refrain from or anticipates the use of any drug, including prescription and
             non-prescription medications, herbal remedies, or vitamin supplements beginning 14
             days prior to dosing and throughout the study. Thyroid hormone replacement medication
             may be permitted if the participant has been on same stable dose for the last 3 months
             prior to study drug administration. After dosing, acetaminophen (up to 2 g per 24
             hours) may be administered at the discretion of the Investigator or designee. Hormone
             replacement therapy will also be allowed.

         13. Has been on a diet incompatible with the on-study diet, in the opinion of the
             Investigator or designee, within the 30 days prior to dosing and throughout the study.

         14. Donation of blood or significant blood loss within 56 days prior to dosing.

         15. Plasma donation within 7 days prior to dosing.

         16. Has positive results for Coronavirus disease 2019 (COVID-19) testing at screening or
             check-in.