A Study of GEn-1124 in Subjects With Acute Respiratory Distress Syndrome (ARDS)

Inclusion Criteria: 1. Male or female subject between the ages of 18 and 85 years old, inclusive. 2. Written informed consent . 3. Dosing as early as possible after first meeting ARDS 2023 Global definition. 4. Acceptable method of birth control. Exclusion Criteria: 1. Subject, surrogate, or physician not committed, or eligible, to receive full supportive care measures. 2. Pregnant or breastfeeding 3. Currently incarcerated in a correctional institution or involuntarily committed to an inpatient mental health facility. 4. Active malignancy (other than non-melanoma skin cancer) requiring treatment with immunosuppressant drugs within the last 3 months or within the last 6 months if an anti-B cell antibody was received. 5. Any other irreversible disease or condition for which 6-month mortality is estimated to be \>50%. 6. Moderate to severe liver failure. 7. Estimated glomerular filtration rate (eGFR) \<10 mL/min/1.73 m2 or requiring dialysis at screening. 8. Subjects with known: 1. New York Heart Association Class IV heart disease; or 2. Acute Coronary Syndrome within the past 30 days (e.g., myocardial infarction, unstable angina) or dosing; or 3. Cardiac arrest within 30 days of dosing with sequelae likely to increase mortality. 9. Severe chronic respiratory disease with continuous home oxygen \>2 liters per minute (LPM) or \>28% (adjusted for altitude); and/or home noninvasive ventilation (except for the treatment of obstructive sleep apnea). 10. Poly-traumatic injury resulting in significant blood loss and/or likely to require major surgery within the study period, or subject condition that would interfere with study procedures. 11. History of any type of solid organ or cellular transplant. 12. Receiving immunosuppressive therapy for solid organ or hematopoietic cancer, transplant anti-rejection medication, and/or other chronic conditions. 13. Moribund subject not expected to survive 24 hours. 14. Do not resuscitate (DNR) status. 15. World Health Organization (WHO) functional class III or IV pulmonary hypertension. 16. Subject has been on mechanical ventilation for more than 7 days at time of dosing. 17. Burn victims currently undergoing treatment for \>40% total body surface area (TBSA) involvement or for known airway inhalation injury. 18. Neuromuscular disease that could impact ability to wean from mechanical ventilation. 19. History of tuberculosis (TB); undergoing treatment for latent TB infection (LTBI); untreated LTBI (as determined by documented results within 3 months of Screening of a positive TB test). 20. Active Hepatitis B, positive Hepatitis C (and has not completed antiviral treatment), or positive human immunodeficiency (HIV) screen. 21. Use of any investigational drug or device within last 30 days of dosing or 5 half-lives, whichever is longer. 22. Any other medical, psychiatric, or social condition that, in the opinion of the investigator, is likely to unfavorably alter the risk-benefit of subject participation, to interfere with protocol compliance, or to confound safety.