Phase 1 Study of ULSC in Patients With Polymyositis (PM) and Dermatomyositis (DM)

Inclusion criteria

• Adult, male or female, age ≥18 years old
• Diagnosis of definite or probable DM or PM, according to the criteria of Bohan and Peter
• Patients with PM will either be positive for a myositis-associated antibody or have undergone evaluation to exclude mimics, as deemed appropriate by the Investigator (See Note below).
• Signs informed consent.

Exclusion criteria

• A diagnosis of inclusion body myositis, juvenile DM or PM, myositis in the context of significant overlap with another systemic autoimmune rheumatologic disease.
• Non immune myopathies.
• Cancer associated myositis.
• Hypersensitivity to study product components. History of hypersensitivity to dimethyl sulfoxide (DMSO).
• Pregnant or lactating women.
• Concomitant severe cardiac, pulmonary disease, active infection or other conditions that preclude assessment of safety and efficacy of the study product.
• Patients with predominant muscle atrophy secondary to uncontrolled or chronic DM or PM, based on clinical, biochemical, and/or radiologic assessment, despite previous optimized treatment.
• Anticipated need for surgery during the trial period.
• A history of prevalent noncompliance with medical therapy.
• Recipient of an organ transplant.
• Neutropenia (absolute neutrophil count<1,800/mm3 [or <1,000/mm3 in African-American subjects]).
• Severe impairment in renal function (estimated glomerular filtration rate <30 ml/kg*min).
• Recent or planned use of vaccination with live attenuated viruses.
• Active cancer or prior diagnosis of cancer within the past 2 years (patients with basal and squamous cell cancer of skin will not be excluded).
• Condition that would impair an assessment of muscle strength, including neurological disorders such as Parkinson's disease or severe musculoskeletal condition.
• Any other condition that, in the judgment of the Investigator or Sponsor, would be a contraindication to enrollment, study product administration, or follow-up.
• History of Atrial septal defect or ventricular septal defect