Study halted prematurely and will not resume; participants are no longer being examined or receiving intervention.

This is a phase 1b randomized, double-blind, placebo-controlled study in adult subjects with Coronavirus Disease 2019 (COVID-19). This clinical trial will evaluate the preliminary safety and efficacy of BM-Allo.MSC vs placebo in treating subjects with severe disease requiring ventilator support during COVID 19 infection.

Inclusion Criteria:

1. Age ≥ 18 years old.

2. Able to understand and provide a signed informed consent that fulfills the relevant Institutional Review Board (IRB) or Independent Ethics Committee (IEC) guidelines. For subjects that are intubated and/or sedated, or otherwise unable to provide consent, prospective consent from a legally-authorized representative is required. The subject or his/her legally authorized representative must be able to provide consent.

3. Has laboratory-confirmed positive novel coronavirus (SARS-CoV-2) test, as determined by polymerase chain reaction (PCR), or other commercial or public health assay in any specimen < 72 hours prior to enrollment, or meets the criteria to guide the evaluation and testing of patients under investigation (PUI) for COVID-19 (https://emergency.cdc.gov/han/2020/HAN00428.asp).

4. Requiring mechanical ventilatory support with moderate to severe Acute Respiratory Distress Syndrome (ARDS) as determined by the Berlin criteria:

   1. Bilateral opacities present on a chest radiograph or computed tomographic (CT) scan. These opacities are not fully explained by pleural effusions, lobar collapse, lung collapse, or pulmonary nodules.

   2. Origin of Edema: Respiratory failure not fully explained by cardiac failure or fluid overload.

   3. Oxygenation: Moderate to severe impairment of oxygenation must be present, as defined by the ratio of arterial oxygen tension to fraction of inspired oxygen (PaO2/FiO2). The severity of the hypoxemia defines the severity of the ARDS:

      • Moderate: PaO2/FiO2 >100 mmHg and ≤ 200 mmHg, on ventilator settings that include PEEP ≥ 5 cm H2O
      • Severe: PaO2/FiO2 ≤100 mmHg on ventilator settings that include PEEP ≥5 cm H2O Subjects receiving extracorporeal membrane oxygenation (ECMO) will not be enrolled in this study.

5. High-sensitivity C-reactive Protein (hs-CRP) serum level > 4.0 mg/dL

6. Acute Physiology and Chronic Health Evaluation (APACHE IV) score > 5

7. Agrees to the collection of nasopharyngeal (NP) swabs and venous blood per protocol.

8. Ability to attend required study visits and return for adequate follow-up, as required by this protocol.

9. Agreement to practice effective contraception for female subjects of child-bearing potential and non-sterile males. Female subjects of child-bearing potential must agree to use effective contraception while on study and for at least 1 month after the last dose of BM-Allo.MSC. Non-sterile male subjects must agree to use a condom while on study and for up to 1 month after the dose of BM-Allo.MSC. Effective contraception includes surgical sterilization (eg, vasectomy, tubal ligation), two forms of barrier methods (eg, condom, diaphragm) used with spermicide, intrauterine devices (IUDs), oral contraceptives, and abstinence.

Exclusion Criteria:

1. Known hypersensitivity to any component of the study medication(s).
2. Signs of multisystem organ failure. Liver function tests (LFTs) > 5x normal.
3. Intubated > 72 continuous hours.
4. Assessed by the Investigator to be unable or unwilling to comply with the requirements of the protocol.
5. Pregnant and nursing women. A negative serum pregnancy test during screening (within 72 hours prior to the first dose) must be documented before MSCs are administered to a female subject of child-bearing potential.

From randomization through 30 days past the last dose, up to 34 days.

The study is terminated early due to low enrollment. Efficacy of the Investigational Product is not analyzed.

Race was not collected in the CRFs for subjects and therefore is not presented in the data output for these subjects.

Treatment-Emergent Adverse Events Table includes Serious Adverse Events.