Mesenchymal stem cells can be isolated from bone marrow, placenta, adipose tissue, human cord blood, and other human tissue. They can differentiate into bone, cartilage, muscle fat, and fibroblasts. Several preclinical investigations have reported that mesenchymal stem cells have an impressive ability to modulate the immune system; reducing the severity of organ injury as well as enhancing recovery. Mesenchymal stem cells also have a positive safety record in clinical trials so far and have been approved in Canada for use in patients with cancer.

The 9 patient Phase I clinical trial for safety has been completed with no safety concerns. The Phase II clinical trial has now begun with over 40 patients enrolled thus far and a planned enrollment of 60 patients. It is a blinded randomized trial with 2:1 randomization (2 mesenchymal stem cells to 1 placebo).

The purpose of this Phase II trial is to determine the safety of allogeneic bone marrow-derived human mesenchymal stem cells in patients with severe ARDS.

Inclusion Criteria:

Criteria 1-3 must all be present within a 24-hour time period and at the time of enrollment:

Acute onset of:

1. A need for positive pressure ventilation by an endotracheal or tracheal tube with a PaO2/FiO2 ratio < 200 with at least 8 cm H2O positive end-expiratory airway pressure (PEEP)

2. Bilateral infiltrates consistent with pulmonary edema on frontal chest radiograph

3. No clinical evidence of left atrial hypertension for bilateral pulmonary infiltrates

Exclusion Criteria:

1. Age less than 18 years

2. Greater than 96 hours since all inclusion criteria met

3. Pregnant or breast-feeding

4. Prisoner

5. Presence of any active malignancy that required treatment within the last 2 years or other irreversible disease or condition for which 6-month mortality is estimated to be greater than 50%

6. Moderate to severe liver failure (Childs-Pugh Score > 12)

7. Severe chronic respiratory disease with a PaCO2 > 50 mm Hg or the use of home oxygen

8. Patient, surrogate, or physician not committed to full support (Exception: a patient will not be excluded if he/she would receive all supportive care except for attempts at resuscitation from cardiac arrest).

9. Major trauma in the prior 5 days

10. No consent/inability to obtain consent

11. Moribund patient not expected to survive 24 hours

12. WHO Class III or IV pulmonary hypertension

13. Documented deep venous thrombosis or pulmonary embolism within past 3 months

14. No arterial line/no intent to place an arterial line

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

Patients can receive the stem cell treatment within 120 hours of the onset of ARDS symptoms.

More information about the study can be found here: clinicaltrials.gov