 - For Cohort 5: Acute spinal cord injury tetraplegic patients with confirmed classification of ASIA A: Cervical lesions C5 lesion T1. 4-28 days post-injury i.e. study drug treatment must begin 4-28 days post injury. Tetraplegic patients who are allowed to start treatment are those who either do not require mechanical ventilation or who do not completely depend on mechanical ventilation but show some degree of spontaneous ventilation. Only those modes of ventilation where the patient must initiate all breaths are allowed e.g. continuous positive airway pressure CPAP. 