Here is the design of a clinical trial:

Official Title: Allogeneic Human Umbilical Cord-derived Mesenchymal Stem/Stromal Cells for Chronic Obstructive Pulmonary Disease (COPD): Study Protocol for a Matched Case-control, Phase I/II Trial

Included conditions:
- COPD

Study Armgroups:
- {'label': 'Treatment (UC-MSC trasnplatation)', 'type': 'EXPERIMENTAL', 'description': '1 x 10\\^6 umbilical Cord Mesenchymal Stem Cells per body kg will transplant via the intravenous at baseline, and the second transplantation will be performed 3 months after the first transplantation and combination with Vietnames MOH procedure', 'interventionNames': ['Biological: Umbilical Cord Mesenchymal Stem Cells transplantation', 'Drug: drug therapy according to Vietnamese MOHS procedure']}
- {'label': 'control arm', 'type': 'OTHER', 'description': 'drug therapy according to Vietnamese MOHS procedure', 'interventionNames': ['Drug: drug therapy according to Vietnamese MOHS procedure']}

Interventions:
- {'type': 'BIOLOGICAL', 'name': 'Umbilical Cord Mesenchymal Stem Cells transplantation', 'description': 'Patients assigned to UC-MSC administration groups will receive two administrations at a dose of 1 million cells/kg patient body weight via the IV route with a 3-month intervening interval', 'armGroupLabels': ['Treatment (UC-MSC trasnplatation)']}
- {'type': 'DRUG', 'name': 'drug therapy according to Vietnamese MOHS procedure', 'description': 'Salbutamol, Terbutaline', 'armGroupLabels': ['Treatment (UC-MSC trasnplatation)', 'control arm']}

Primary Outcomes:
- {'measure': 'Adverse events and serious adverse events', 'description': 'To assess safety, the number of AEs or SAEs during stem cell administration (72 h) at 3 months, 6 months, and 12 months after discharge will be evaluated', 'timeFrame': 'up to the 12-month period following treatment'}

Please estimate the sample size based on the assumption: 
α = 0.05, β = 0.2
Sample size
        As a previous study indicated that the FEV1 (%) of patients with COPD was reduced to 35.4%Â±7.1% (6% reduction) after 6 months postadministration, we set this indicator at 18% reduction after 12 months postadministration to calculate the minimum sample size for the proposed study.18 21 According to the continuous endpoint of two independent sample studies,22 we assumed Î± was 0.05 and type-II error Î² was 0.2; thus, the smallest sample size was 40 patients. The calculated sample size was 20 for each group.