This is a phase 2, multi-center, randomized study (n=82, 1:1 MSC:placebo) where consented patients will receive 4 intravenous doses of IMP over a period of 2 weeks. Patients must provide written informed consent and meet the all Inclusion Criteria and none of the Exclusion Criteria to be eligible. Screening procedures include obtaining medical history, current medications, questionnaires, vital signs, Chest Xray, 6 Minute walk test and blood tests. Historical chest CT and full lung function from 12 weeks prior to screening may be used. Bronchoscopy with biopsy must have been performed no more than 6 months prior to screening. A bronchoscopy with bronchoalveolar lavage (BAL) is required, however will not need to be repeated if performed within 14 days prior to the baseline visit. Patients will then receive 4 infusions of MSC/placebo over a period of 2 weeks, with follow up at Week 3,6,10,14,28,41 and week 54.