Phase 1 First-in Human randomized, open-label, active control standard of care study of the safety of HBN-1 administered as pharmacologically induced hypothermia as an adjunct to standard of care targeted temperature management in adult patients who have experienced out-of-hospital-cardiac arrest. HBN-1 will be administered IV as a loading dose infusion followed by a 12-hour maintenance infusion.

Phase 1 First-in Human randomized, open-label, active control standard of care study of the safety of HBN-1 administered as pharmacologically induced hypothermia as an adjunct to standard of care targeted temperature management in adult patients who have experienced out-of-hospital-cardiac arrest.

HBN-1 will be administered as an IV solution according to a weight-based escalating loading dose infusion rate scheme involving three sequential cohorts with a loading dose of HBN 1 administered over 60 minutes (Cohort A), 45 minutes (Cohort B), or 30 minutes (Cohort C). For all cohorts, the loading dose will be followed by a 12-hour maintenance infusion of HBN-1.

Dosing cohorts will include a minimum of 6 subjects randomized in a 2:1 ratio of HBN-1 plus standard of care versus standard of care alone. Individual cohorts may be expanded to up to a maximum of 12 subjects . If the cohort is expanded, the additional subjects will receive HBN-1 + SOC.

During the loading dose and maintenance infusion, physical exam, temperature, assessment of shivering, ECG, vital signs, clinical laboratory, blood alcohol level, and neurologic status will be monitored.

Inclusion Criteria:

1. Age 40 to 80 years, inclusive
2. Documented diagnosis of OHCA with ventricular tachycardia/fibrillation, asystole or pulseless electrical activity
3. Return of spontaneous circulation within 50 minutes of the event
4. FOUR Motor Score <4
5. Maximum estimated weight not to exceed 100 kg

Exclusion Criteria:

1. Return of spontaneous circulation >8 hours
2. Known history of prior cardiac arrest, alcohol, or substance abuse or dependence
3. Presumed etiology of cardiac arrest is trauma, hemorrhage, or sepsis
4. Comfort measures only or anticipated withdrawal of life-support within 24 hours
5. Is within a protected population group (eg, pregnant or breastfeeding or incarcerated persons)
6. Has history or evidence of significant hepatic dysfunction (Sequential Organ Failure Assessment Hepatic score >2)
7. Any other condition, that in the opinion of the investigator, would preclude the subject from being a suitable candidate, e.g. end-stage chronic illness with no reasonable expectation of survival to hospital discharge
8. Is able to obey to verbal commands
9. Is receiving IV vasopressin or lidocaine hydrochloride