The purpose of this study is to compare the absorption and blood levels of IX-01 when given as a capsule compared to liquid form, and how food affects the absorption in healthy men.

Inclusion Criteria:

• A body mass index (Quetelet index) in the range 18-30 kilograms/meters squared (kg/m2)
• Body Mass Index = weight [kg] divided by (height [m])2
• Total body weight greater than (>)50 kg at screening
• Ability to communicate satisfactorily with the investigator and to participate in, and comply with the requirements of, the entire trial
• Participants and their partners must be willing to use adequate forms of contraception and to comply with the contraception requirements during the trial and for 4 months after the last dose of medication
• Willingness to give written consent to have data entered into The Over Volunteering Prevention System

Exclusion Criteria:

• Clinically relevant abnormal history, physical findings, ECG, or laboratory values at the pre-trial screening assessment, including:

  • Lipid and/or liver function test results >1.25 x Upper Limit of Normal (ULN) or other clinical laboratory blood biochemistry test results outside the normal reference range unless discussed and approved by sponsor
  • International normalised ratio (INR) of >1.2 or a platelet count < 150 x 109/Liter
  • History of unexplained syncope
  • Family history of unexplained sudden death, or sudden death due to long QT syndrome
  • Fridericia Correction Formula (QTcF) interval >450 milliseconds (msec) at screening
  • Bundle branch block and other conduction abnormalities, other than mild first degree atrio-ventricular block
  • Irregular rhythms other than sinus arrhythmia or occasional supraventricular ectopic beats
  • T-wave configuration of insufficient quality for determination of QT interval, as assessed by the investigator

• Presence of acute or chronic illness or history of chronic illness sufficient to invalidate participation in the trial

• Impaired gastrointestinal, endocrine, thyroid, hepatic, cardiovascular, respiratory, haematological, renal or neurological function, diabetes mellitus, coronary heart disease, or history of any psychotic mental illness

• Surgery (for example (e.g.) stomach bypass) or medical condition that might affect absorption, metabolism or elimination of medicines

• Any skin condition, abnormality of the lumbar spine, medical or surgical condition that would preclude lumbar puncture (e.g. coagulopathy, local or systemic infection, left ventricular outflow obstruction, aortic stenosis, previous back surgery)

• Presence or history of severe adverse reaction to any drug

• Use of any prescription or over-the-counter medicine during the 14 days before the first dose of trial medication, or intention to use any medicine during the trial, with the exception of short courses of medication considered by the investigator not to interfere with the safety of the participant or the integrity of the trial data (such as acetaminophen (paracetamol))

• Current use of any herbal remedy or nutritional supplement, or intention to use any such product during the study

• Participation in another clinical trial of a new chemical entity or a prescription medicine within the previous 3 months.

• Previous participation in this trial or any other clinical trial of an oxytocin receptor antagonist

• Presence or history of drug or alcohol abuse, or intake of more than 21 units of alcohol weekly or more than 5 cigarettes daily

• Blood pressure and heart rate in supine position at the screening examination outside the ranges 100-130 millimeters of mercury (mm Hg) systolic, 60-90 mm Hg diastolic; heart rate 50-100 beats/minute. Measurements must be made in duplicate, and all values must fall within the acceptable ranges

• Possibility that the participant will not cooperate with the requirements of the protocol

• Evidence of drug abuse on urine testing

• Positive test for hepatitis B, hepatitis C, Human Immunodeficiency Virus 1 (HIV1) or Human Immunodeficiency Virus 2 (HIV2)

• Loss of more than 400 mL blood during the 3 months before the trial, e.g. as a blood donor

• Objection by General Practitioner (GP), on medical grounds, to participant entering trial

• Employee of the investigator site or any company involved in sponsoring, organizing or conducting the trial, or immediate family of the employee

Up to 6 weeks

The onset date/time of one non-serious event (toothache) was not recorded, so the treatment arm was unknown and not shown below, otherwise all events that occurred during the study period are shown including those that were unrelated