The clinical study with UMC119-06 is designed to investigate the safety in patients with moderate acute respiratory distress syndrome ("ARDS"). This will be a dose escalation, open-label, single-center study in adult with ARDS. UMC119-06 is ex vivo cultured human umbilical cord derived mensenchymal stem cells (hUC-MSCs) product which is intended for treatment of ARDS.

ARDS, a noncardiogenic respiratory disease, is characterized by progressive hypoxemia and respiratory distress, associated with explosive acute inflammation and alveolar edema. ARDS occurs in all age group of patients, where mortality rates increase in advancing age.

In animal studies of ARDS, mensenchymal stem cells (MSCs) can attenuate lipopolysaccharides (LPS)-induced lung injury and pulmonary permeability edema through modulating the inflammatory. These findings show that MSCs may improve the clinical outcomes and prognosis of ARDS patient. Meridigen is developing UMC119-06, human umbilical cord-derived MSCs, for the treatment of ARDS. The purpose of this study is to assess the safety of UMC119-06 in patients with ARDS.

Inclusion Criteria:

• Subjects of age ≥ 20 years and ≤ 85 years.

• Subject has a diagnosis of moderate ARDS according to the Berlin definition of ARDS:

  1. No clinical evidence of left atrial hypertension for bilateral pulmonary infiltrates.
  2. Bilateral infiltrates consistent with pulmonary edema on frontal chest radiograph.
  3. Hypoxemia: PaO2/ FiO2 > 100 mmHg to ≤ 200 mmHg with PEEP ≥ 5 cm H2O.
  4. The time of onset of ARDS is when all of the specified ARDS criteria (2a-c) are met.

• Patient is intubated and mechanically ventilated.

• Subjects who had an onset of ARDS within 72 to 120 hours before start of treatment.

• Subjects with body weight between 40 to 90 kg.

• No decompensated heart failure.

• Subject is willing to provide written informed consent to participate in the study after reading the informed consent form and the information provided.

• Women of child-bearing potential should have a negative serum pregnancy test prior to administration of investigational product., UNLESS they meet the following criteria:

  1. Post-menopausal: 12 months of natural (spontaneous) amenorrhea or 6 months of spontaneous amenorrhea with serum Follicle Stimulating Hormone (FSH) levels > 40 mIU/ml, OR;
  2. 6 weeks post-surgical bilateral oophorectomy with or without hysterectomy.

Exclusion Criteria:

• Greater than 72 hours since first meeting ARDS criteria per the Berlin definition.

• No intent/unwillingness to follow lung protective ventilation strategy or fluid management protocol.

• Expected life < 3 months from other cause than the respiratory failure.

• Subject is receiving extra-corporeal membrane oxygenation, high-frequency oscillatory ventilation or any form of extra-corporeal lung support.

• Subjects with history of any type of malignancy.

• Major trauma in the prior 5 days.

• Subjects with major surgery (body organs that require anesthesia, such as tumor removal, open chest, heart surgery, abdominal surgery, intracranial surgery, or normal surgery for more than 3 hours, etc.) within previous 14 days.

• Subjects who are pregnant (or plan to become pregnant within 3 months of investigational product treatment) or lactating.

• Subjects who have a significant concomitant illness as judged by principal investigator (PI).

• Subjects who have significant abnormal laboratory tests at screening:

  1. >5 × upper limit of normal for alanine aminotransferase (ALT) or aspartate aminotransferase (AST).
  2. >3 × upper limit of normal for total bilirubin.
  3. >2 × upper limit of normal for serum creatinine.

• Subjects with known human immunodeficiency virus infection or who are immune compromised.

• Subjects who are unable to return for follow-up visits for clinical evaluation, laboratory studies, or imaging evaluation.

• Subjects with a history of severe allergic or anaphylactic reactions.

• Subjects with known allergy or hypersensitivity to any component of the formulation (normal saline and human serum albumin).

• Subjects who have participated in another clinical study of new investigational therapies or have received an investigational therapy within the 12 weeks before study drug administration.