Study of NNZ-2566 in Patients With Traumatic Brain Injury Under EFIC

Inclusion Criteria: * Non-penetrating TBI. * Age 16-75 years. * Admission to hospital. * Post resuscitation GCS 4-12. * Have at least one reactive pupil. * Able to receive investigational product within 8 hours of injury. * Hemodynamically stable after resuscitation (systolic blood pressure (SBP) \>100 mm Hg). * Able to read and write English and have sufficient motor dexterity prior to injury to undertake the neuropsychological and activities of daily living (ADL) testing, in the opinion of the investigator, at 1 month (defined as 4-6 weeks) and 3 months (defined as 12-14 weeks) post injury. Exclusion Criteria: * Penetrating brain injury. * Spinal cord injury. * Presence or known history of prior cerebral injury requiring hospitalization that would, in the opinion of the Investigator, interfere with or bias the assessment of efficacy. * Non-traumatic brain injury. * Known history of any medical or psychiatric disorder, or any severe concomitant disease that would, in the opinion of the Investigator, interfere with or bias the assessment of efficacy. * Significant non-central nervous system (CNS) injuries sustained at the time of the TBI would, in the opinion of the Investigator, interfere with or bias the assessment of efficacy. * Weight \>150 kg. * Participation in another clinical trial within the previous 4 weeks. * Clinical state requiring greater than 6 L blood, colloid or crystalloid fluid resuscitation prior to randomization. * Pregnant or nursing mothers. Women of child-bearing potential must have a negative urine or blood test prior to randomization. * Prior enrollment in this study. * QTc Exclusions. The study will use the exclusion criteria as defined in ICH Guideline E14 to exclude patients with a risk of QT/QTc prolongation, as follows: * A marked baseline prolongation of corrected QT/QTc interval \>450 ms. * History of risk factors for torsade de pointes (e.g. heart failure, hypokalemia (serum potassium at screening \<3.0 mmol/L)or family history of long QT syndrome).