Background There are sparse data on long-term and late effects of hematopoietic cell transplantation (HCT) for sickle cell disease (SCD) Objectives To establish an international registry of long-term outcomes post-HCT for SCD and demonstrate the feasibility of recruitment at a single site in the US. Methods The STELLAR registry is designed to enroll SCD patients ≥ 1-year post-HCT, their siblings without SCD, and non-transplanted SCD controls to collect participant self-report of health status and practices using the BMT survivor study surveys, HRQOL using PROMIS 25 or 29, cGVHD using the symptom scale survey, daily pain using an electronic pain diary, economic impact of HCT using the financial hardship survey, and sexual function using PROMIS SexFSv2.0. We also piloted retrieval of clinical data previously submitted to CIBMTR, recorded demographics, height, weight, BP, hip and waist circumference, timed-up-and-go, and handgrip test, and obtained blood for metabolic screening, gonadal function, fertility potential, and biorepository of plasma, serum, RNA, and DNA. Results Among 100 eligible post-HCT patients, we enrolled 72 participants 9-38 (median 17) years age. We also enrolled 19 siblings 5-32 (median10)years age and 28 non-transplanted SCD controls 4-46 (median 22) years age. Of 119 participants, 73 completed 85 sets of surveys and 41 contributed samples to the biorepository. We successfully piloted retrieval of data submitted to CIBMTR and expanded recruitment to seven US, Canada, UK, and Nigeria sites. Conclusions It is feasible to recruit subjects and conduct study procedures for the STELLAR registry of long-term and late effects of HCT for SCD.

Background: The NIH non-myeloablative regimen has been successfully implemented for pediatric sickle cell disease (SCD) patients undergoing matched sibling donor (MSD) hematopoietic stem cell transplant (HSCT) in an effort to prevent late complications, including infertility and other endocrine sequelae. This retrospective cohort analysis evaluated the prevalence of endocrine complications in 17 pediatric SCD patients who underwent non-myeloablative MSD HSCT. Procedure: Medical records between June 2013 and June 2020 were reviewed. Data was extracted from baseline and 1,2,3, and 5-years post HSCT. Results: There were 12 females and 5 males. Follicle stimulating hormone (FSH) elevation post HSCT occurred in 42.8%; 4 females and 2 males. All females with elevated FSH had subsequent normalization of their values with time. FSH elevation in males did not resolve. Post HSCT secondary amenorrhea or oligomenorrhea was described in 4 females; however, improvement or resolution occurred in all. One female subject with normal gonadotrophin levels post HSCT had a successful pregnancy and live birth. Vitamin D deficiency (100% when measured), and obese or overweight body mass index post HSCT (41.2%) were also reported. Conclusions: A notable endocrine issue post HSCT described in this cohort is FSH elevation. The elevation was transient in females, and we identified one successful pregnancy, suggesting that non-myeloablative conditioning may convey favorable fertility outcomes compared to busulfan-based conditioning. Not all patients had baseline endocrine evaluations or consistent post HSCT endocrine testing. We recommend standardizing pre- and post HSCT endocrinology assessments for this population.

Background Hematopoietic stem cell transplantation can be curative for children with difficult to treat leukemia. The conditioning regimen utilised is known to influence outcomes. We report outcomes of the conditioning regimen used at the Alberta Children’s Hospital, consisting of busulfan (with pharmacokinetic target of 3750μmol*min/day +/-10%) for 4 days, higher dose (250 mg/m2) fludarabine and 400 centigray of total body irradiation. Procedure This retrospective study involved children receiving transplant for acute lymphoblastic leukemia (ALL). It compared children who fell within the target range for busulfan with those who were either not measured or were measured and fell outside this range. All other treatment factors were identical. Results Twenty-nine children (17 within target) were evaluated. All subjects engrafted neutrophils with a median (IQR) time of 14 days (8-30 days). The cumulative incidence of acute graft versus host disease was 44.8% (95% CI 35.6 – 54.0%), while chronic graft versus host disease was noted in 16.0% (95% CI 8.7% - 23.3%). At two years, the overall survival was 78.1% (95% CI 70.8% - 86.4%) and event free survival was 74.7% (95% CI 66.4% - 83.0%). Cumulative incidence of relapse was 11.3% (95% CI 5.1% - 17.5%). There were no statistically significant differences in between the group that received targeted busulfan compared with the untargeted group. Conclusion The current regimen used in children with ALL results in outcomes comparable to standard treatment with acceptable toxicities and significant reduction in radiation dose. Targeting Busulfan dose in this cohort did not result in improved outcomes.

Background/Objectives. Despite advances in the treatment of sickle cell disease (SCD), cerebrovascular and cognitive consequences can be lifelong. Hematopoietic cell transplantation (HCT) is an established curative therapy and recent studies have demonstrated efficacy with reduced toxicity nonmyeloblative (NMA) regimens, but little is known about neuropsychological outcomes. The objective of this study was to describe neuropsychological, behavioral, and quality of life outcomes with medical correlates in children with SCD who received an NMA matched sibling donor (MSD) HCT. Design/Methods. This retrospective cohort analysis of nine patients with hemoglobin SS SCD underwent MSD HCT using the National Institutes of Health (NIH) NMA protocol. Results. Mean full scale intellectual functioning (FSIQ) was average pre-HCT (FSIQ=92.1, SD 9.0; n=8) and 2 years post-HCT (mean FSIQ=96.6; SD 11.1; N=9). Neuropsychological functioning was largely average across all cognitive domains. Moderate improvements were seen in processing speed and verbal memory (Cohen’s d=0.50-0.57) post-HCT, and declines occurred in measures of attention and fine motor speed and dexterity (Cohen’s d=0.70-0.81). Parents reported improved quality of life (Cohen’s d=0.91), less impact of SCD on their family, and less worry about their child’s future (Cohen’s d=1.44). Exploratory analysis showed relationships between pre-HCT hemoglobin (r=0.74, p<0.05) and creatinine (r=-0.75, p<0.01) with cognitive functioning, and a positive relationship between processing speed and time post-HCT (r=0.73). Conclusion. Neuropsychological functioning in a sample of children and adolescents treated identically with NMA MSD HCT remained stable or improved in most cognitive domains, and improvements in quality of life and family functioning were observed.