Study to investigate the safety of ENX-101 and how well it works in healthy volunteers.

INTERVENTION: Administration of up to 50 mg of ENX‐101 or a matching placebo. CONDITION: Epilepsy, spasticity and anxiety disorders ; Not Applicable PRIMARY OUTCOME: The safety and tolerability of ENX‐101 will be assessed using the following:; 1. Adverse events (AEs) recorded throughout the study; 2. Physical examination at Screening, Day ‐2, Day 10, Prior to discharge on Day 13; 3. Vital signs* (blood pressure, HR, respiratory rate and tympanic body temperature) at Screening, Day –2, Day –1, Day 1 through Day 10: Pre‐dose, 2 and 6 hours after dosing, Day 11 through Day 13; *Vital signs will include two‐position blood pressure and heart rate (HR), respiratory rate, and tympanic temperature. Blood pressure and HR will be measured in both the supine and standing positions; measurements will be performed after at least 10 minutes lying down and then at 2 minutes after rising from the supine position to standing; 4. Continuous 12‐lead ECG holter monitoring on Day –1: timepoints scheduled to approximately match the Day 1 timepoints; Day 1: 60, 45, and 30 minutes pre‐dose and 0.5, 1, 2, 3, 4, 5, 6, 7, 8, 10, 12, and 24 hours after dosing; Day 10: 60, 45, and 30 minutes pre‐dose and 0.5, 1, 2, 3, 4, 5, 6, 7, 8, 10, 12, and 24 hours; 5. Clinical laboratory tests (hematology, serum chemistry, serum coagulation, urinalysis) at Screening, Day ‐2, Day 5, Day 10, and Day 13; 6. Suicidality (suicidal behavior and suicidal ideation) assessed using the Columbia Suicide Severity Rating Scale (C‐SSRS) at Screening, Day 1, Day 2, Day 5, Day 11, Day 13; 7. Degree of sedation assessed using the Modified Observer's Alertness/Sedation Scale (MOAA/S) at Day 1: Pre‐dose and 2, 4, 6, 8, 10, and 24 hours (Day 2) after dosing; Day 10: Pre‐dose and 2, 4, 6, 8, 10, and 24 hours (Day 11) after dosing; Day 12: 48 hours after Day 10 dosing; Day 13: 72 hours after Day 10 dosing INCLUSION CRITERIA: 1. Healthy male and female volunteers aged 18 to 55 years, inclusive, at Screening 2. Capable of giving written informed consent 3. Willing to give written consent to have data entered into "Verified Clinical Trials" 4. Female subjects 4.1. Of non‐childbearing potential, defined as either permanently sterilized (at least 4 months after surgical sterilization including bilateral salpingectomy, tubal ligation, or oophorectomy with or without hysterectomy) or post‐menopausal (defined as amenorrhea for 12 consecutive months and documented plasma follicle‐stimulating hormone level >40 IU/mL; in the event a subject's menopausal status has been clearly established and yet serum follicle‐stimulating hormone levels are not consistent with a post‐menopausal status, determination of the subject's eligibility to be included in the study will be at the Investigator's discretion following consultation with the Sponsor), and with a negative pregnancy test at Screening SECONDARY OUTCOME: 1. The effects of ENX‐101 on the following electrocardiogram (ECG) parameters in healthy volunteers: cardiac repolarization (corrected QT interval [QTc]), heart rate (HR), PR and QRS intervals, T‐wave morphology, and U‐wave presence; measured using 12‐lead ECG at Screening, Day ‐2, Day 1: Pre‐dose and 2 and 6 hours after dosing, Day 10: Pre‐dose and 2 and 6 hours after dosing, Day 13; 2. The PK of ENX‐101 and, if possible, ENX‐101 metabolites (ENX‐101‐M3, triazole aldehyde, triazole alcohol, and triazole acid), in plasma of healthy volunteers after the first dose and at plasma steady‐state at Day 1: Pre‐dose and at 0.5, 1, 2, 3, 4, 5, 6, 7, 8, 10, and 12 hours after dosing; Day 2: Pre‐dose (24 hours after Day 1 dose) and 1, 2, 4, 6, 8, 10, and 12 hours after dosing; Days 3, 4, 5, 6, 7, and 8: Pre‐dose (24 hours after the previous day’s dose); Day 9: Pre‐dose (24 hours after Day 8) and 1, 2, 4, 6, 8, 10, and 12 hours after dosing; Day 10: Pre‐dose (24 hours after Day 9) and at 0.5, 1, 2, 3, 4, 5, 6, 7, 8, 10, and 12 hours after dosing; Days 11, 12, 13: At 24, 48, and 72 hours respectively, after Day 10 dosing; 3. The effects of ENX‐101 on a battery of pharmacodynamic (PD) measures (NeuroCart®):; 3.1. Saccadic reaction time (seconds), saccadic peak velocity (degrees/second); 3.2. Smooth pursuit eye movements (percentage of time the eyes of the participant are in smooth pursuit of the target) (%); 3.3. Adaptive tracking (average performance) (%); 3.4. Body sway (anteroposterior sway) (mm); 3.5. Pupil size; 3.6. VAS according to Bond and Lader, to assess mood, alertness and calmness (mm); 3.7. VAS according to Bowdle, to assess external and internal perception; Measured at Screening, Day ‐2 (twice during the day for baseline measurement), Day 2 and Day 9: At 2, 4, 6, 8, 10, and 24 hours (i.e. Day 3 and Day 10) after dosing.; 4. The effects of ENX‐101 on the memory test: Visual Verbal Learning Test (VVLT): immediate recall, delayed recall, delayed recognition; measured on Day –2: Learning and Immediate Recall on first training and Delayed Recall and Delayed ; Recognition on second training; Day 2: Learning and Immediate Recall 4 hours after dosing; Delayed Recall and Delayed ; Recognition at 6 and 24 hours (pre‐dose on Day 3) after dosing; Day 9: Learning and Immediate Recall 4 hours after dosing; Delayed Recall and Delayed Recognition at 6 and 24 (pre‐dose on Day 10) hours after dosing; 5. The effects of ENX‐101 on qEEG parameters: a‐band (8.5 <12.5), ß‐band (12.5 <30.0), d‐band (1.5 <6), ?‐band (30.0 <40.0), ?‐band (6.0 <8.5); measured at Day –2; Days 2: Pre‐dose and 2, 4, 6, 8, 10, and 24 hours (Day 3) after dosing; Day 9: Pre‐dose and 2, 4, 6, 8, 10, and 24 hours (Day 10) after dosing ; 6. The effects of ENX‐101 on sedation measured with the MOAA/S on Day 1: Pre‐dose and 2, 4, 6, 8, 10, and 24 hours (Day 2) after dosing; Day 10: Pre‐dose and 2, 4, 6, 8, 10, and 24 hours (Day 11) after dosing; Day 12: 48 hours after Day 10 dosing; Day 13: 72 hours after Day 10 dosing