hCT-MSC in Children With Autism Spectrum Disorder

The purpose of this Phase II study is to determine the efficacy of human umbilical cord tissue-derived mesenchymal stromal cells (hCT-MSC) for improving social communication abilities in children with autism spectrum disorder (ASD).

Inclusion Criteria 1. Age ≥ 4 years to \< 12 years (11 years, 364 days) at the time of consent 2. Confirmed clinical DSM-5 diagnosis of Autism Spectrum Disorder using the DSM-5 Checklist as informed by the Brief Observation of Symptoms of Autism (BOSA) and the Autism Diagnostic Interview-Revised (ADI-R) 3. Fragile X testing performed and negative; CMA and/or whole exome sequencing performed and results not linked to autism diagnosis 4. Stable on current psychiatric medication regimen (dose and dosing schedule) for at least 2 months prior to infusion of study product 5. Normal absolute lymphocyte count (≥1200/uL for African American participants and ≥1500/uL for all other participants) 6. GAI ≥ 65 via cognitive testing by study personnel 7. Participant and parent/guardian are English speaking 8. Able to travel to Duke University two times (baseline, six months), and parent/guardian is able to participate in interim surveys and interviews 9. Parental/guardian consent from at least one parent/guardian Exclusion Criteria 1. General: 1. Review of medical records and/or screening assessments indicates ASD diagnosis and/or GAI \> 65 not confident 2. Known diagnosis of any of the following coexisting psychiatric conditions: depression, bipolar disorder, schizophrenia, obsessive compulsive disorder associated with bipolar disorder, Tourette syndrome 3. Screening data suggests that participant would not be able to comply with the requirements of the study procedures as assessed by the study team 4. Family is unwilling or unable to commit to participation in all study-related assessments, including protocol follow up 5. Sibling is enrolled in this (Duke IMPACT) study 2. Genetic: 1. Records indicate that child has a known genetic syndrome such as (but not limited to) Fragile X syndrome, neurofibromatosis, Rett syndrome, tuberous sclerosis, PTEN mutation, cystic fibrosis, muscular dystrophy or a genetic defect definitively known to be associated with ASD 2. Known pathogenic mutation or copy number variation (CNV) associated with ASD (e.g., 16p11.2, 15q13.2, 2q13.3) 3. Infectious: 1. Known active CNS infection 2. Evidence of uncontrolled infection based on records or clinical assessment 3. Known HIV positivity 4. Exposure to COVID-19 in the preceding 14 days or positive COVID-19 test in the previous 28 days. Subjects with a past history of infection with COVID-19 must be symptom-free for 14 days prior to the initial visit. 4. Medical: 1. Known metabolic disorder 2. Known mitochondrial dysfunction 3. History of unstable epilepsy or uncontrolled seizure disorder, infantile spasms, Lennox Gastaut syndrome, Dravet syndrome, or other similar chronic seizure disorder 4. Active malignancy or prior malignancy that was treated with chemotherapy 5. History of a primary immunodeficiency disorder 6. History of autoimmune cytopenias (i.e., ITP, AIHA) 7. Coexisting medical condition that would place the child at increased risk for complications of study procedures 8. Concurrent genetic or acquired disease or comorbidity(ies) that could require a future stem cell transplant 9. Significant sensory (e.g., blindness, deafness, uncorrected hearing impairment) or motor (e.g., cerebral palsy) impairment 10. Impaired renal or liver function as determined by serum creatinine \>1.5mg/dL or total bilirubin \>1.3mg/dL, except in patients with known Gilbert's disease 11. Significant hematologic abnormalities defined as: Hemoglobin \