Abstract 6
Introduction
An expanded access protocol (EAP) of autologous or sibling umbilical cord blood (CB) infusion was established in 2017 under Investigational New Drug #15949 to provide access to this investigational procedure for individuals with certain neurological conditions who do not qualify for available clinical trials.
Objective
The objective was to report updated enrollment and safety data from a single center EAP of autologous/sibling CB infusion for children with acquired neurological conditions.
Methods
Children with autism, cerebral palsy, and other related conditions were screened remotely under a separate institutional review board‐approved screening protocol, including review of parental questionnaires, medical records, basic labs, and CB unit reports. Based on emerging clinical trial data, the minimum cell dose was increased to a total nucleated cell count (TNCC) >2.0 × 107/kg. CB units also had to have viability >70%, negative sterility cultures and maternal donor screening labs, and a segment available for identity confirmation and potency testing, and sibling units had to be at least human leukocyte antigen‐haploidentical. CB units were thawed, washed, and infused via peripheral IV after premedication with IV diphenhydramine and methylprednisolone. Some children received repeated doses, when the TNCC allowed.
Results
A total of 2,001 children were screened from November 2017 to June 2021, and 464 children received 494 CB infusions under the EAP, including 20 children who had previously participated in a clinical trial and elected to return to receive a subsequent infusion. Due to COVID restrictions, enrollment was suspended for 18 weeks (March 11, 2020, to July 21, 2020). Patient and CB characteristics are shown in Table 1. Infusions were generally well‐tolerated. Forty‐one (9%) adverse events, all hypersensitivity reactions, were probably or definitely related to CB infusion. Serious adverse events were documented in 8 children, all expected and unrelated to CB infusion. There were 6 (0.01%) positive post‐thaw cultures; none developed infections or required antibiotics. Parental surveys were completed 1 year (n = 244, 72%) and 2 years (n = 105, 51%) post‐infusion. Parental assessment varied regarding clinical improvement.
Table 1.
Recipient, cord blood, and infusion characteristics
| Characteristics | Median | Range or % |
|---|---|---|
| Patient characteristics (N = 464) | ||
| Age, years, median (range) | 6.0 | 0.2‐23.4 |
| Sex, n (%) | ||
| Male | 335 | 72% |
| Female | 129 | 28% |
| Race, n (%) | ||
| Caucasian | 335 | 72% |
| Non‐Caucasian | 129 | 28% |
| Diagnosis, n (%) | ||
| Autism | 278 | 60% |
| Cerebral palsy | 122 | 26% |
| Other | 64 | 14% |
| Number of infusions, n (%) | ||
| 1 | 419 | 90% |
| 2+ | 45 | 10% |
| Cord blood infusion characteristics (n = 494) | ||
| Source, n (%) | ||
| Autologous | 246 | 50% |
| Sibling | 248 | 50% |
| Precryo TNCC (×108), median (range) | 4.34 | 0.3‐22.4 |
| Precryo viability (%), median (range) | 94 | 74‐100 |
| Post‐thaw cell dose infused (×107/kg), median (range) | 2.50 | 0.07‐90.2 |
| Positive post‐thaw sterility. n (organisms) | 6 |
Coagulase negative Staphylococcus, ×5 E. coli, ×1 |
Discussion
Autologous/sibling CB infusions conducted under an EAP for children with neurological conditions are safe and feasible with varied reported responses to the infusions. CB eligibility was amended to incorporate early phase clinical trial outcomes regarding cell dose. Efficacy continues to be evaluated in ongoing clinical trials.