Human leucocyte antigen-matched related haematopoietic stem cell transplantation using low-dose cyclophosphamide, fludarabine and thymoglobulin in children with severe aplastic anaemia.

When human leucocyte antigen-matched related donors are available, haematopoietic stem cell transplantation (HSCT) in children with severe aplastic anaemia (SAA) represents the standard of care. Cyclophosphamide (Cy) 200 mg/kg and anti-thymocyte globulin (ATG) are frequently administered, but to-date, no standard conditioning regimen exists. In this study, we investigated the efficacy of a unified HSCT conditioning protocol consisting of low-dose Cy 80 mg/kg, fludarabine and ATG. Data were reviewed from children aged ≤14 years with either acquired SAA or non-Fanconi anaemia inherited bone marrow failure syndrome (IBMFS) between 2011 and 2022 at various Saudi institutions. Graft-versus-host disease (GVHD) prophylaxis included mycophenolate mofetil and calcineurin inhibitors. HSCT was performed in 32 children (17 females and 15 males). Nine patients had deleterious mutations (two ERCC6L2, two ANKRD26, two TINF2, one LZTFL1, one RTEL1 and one DNAJC21). Four patients had short telomeres. All 32 patients engrafted successfully. At 3 years post-transplant, the event-free survival was 93% and overall survival was 95%. Two patients experienced secondary graft failure or myelodysplastic syndrome. A low probability of GVHD was observed (one acute GVHD II and one mild chronic GVHD). These data highlight how HSCT using low-dose Cy as part of a fludarabine-based regimen is safe and effective in SAA/non-Fanconi anaemia IBMFS.

Outcomes of blinatumomab based therapy in children with relapsed, persistent, or refractory acute lymphoblastic leukemia: a multicenter study focusing on predictors of response and post-treatment immunoglobulin production.

The management of Refractory/Relapsed B-cell Acute Lymphoblastic Leukemia (R/R ALL) remains challenging. Incorporating blinatumomab in R/R ALL treatment has shown encouraging results. We describe the outcome and predictors of response in children receiving blinatumomab as a bridge to definitive therapy. Immunoglobulin (Ig) G and viral serology before and after therapy were evaluated. Thirty-three patients that failed standard first-line treatments due to relapsed ALL (n = 22), persistent minimal residual disease (MRD) (n = 8), or refractory disease (n = 3) received blinatumomab. Grade 2 toxicity occurred in 27.2% of patients. MRD remission (<0.01%) was achieved in 72.7% of patients. Pre-blinatumomab absolute lymphocyte count (ALC) and MRD/ALC ratio significantly associated with MRD-response. Patients with t(1;19) translocation had lower response rate, compared to all other cytogenetic categories (p = 0.013). One-year event-free survival (EFS) and overall survival (OS) were 69.2% and 79.7%, respectively. Analysis of OS and EFS showed pre-blinatumomab MRD level, ALC, MRD/ALC ratio, t(1;19), and post-blinatumomab MRD remission associated with survival. Following blinatumomab, 83% (15/18) of tested patients had low IgG levels. IgG seronegative status was observed in 83% (12/15) for varicella zoster, 35% (6/17) for herpes zoster, 18% (3/17) for cytomegalovirus, and 26% (5/17) for Epstein Barr virus. Blinatumomab produced encouraging results in children with R/R ALL and low disease burden bridging to definitive therapy. Incorporating baseline genetics and biomarkers may help identify subgroups likely to be responsive/resistant to therapy. Viral serological testing pre- and post-blinatumomab is recommended to optimize supportive and preemptive therapy.Supplemental data for this article is available online at https://doi.org/10.1080/08880018.2022.2049936 .

High-dose Chemotherapy With Autologous Stem Cell Rescue in Saudi Children Less Than 3 Years of Age With Embryonal Brain Tumors.

High-dose chemotherapy with autologous stem cell rescue (HDC/ASCR) has been used in children under the age of 3 years with embryonal brain tumors to avoid or delay the use of radiation. We reviewed the medical records of 10 Saudi children less than 3 years of age with embryonal brain tumors who underwent HDC/ASCR. All 10 patients underwent surgical resection followed by 3 to 5 cycles of induction chemotherapy and 1 to 3 cycles of HDC/ASCR using carboplatin and thiotepa. Isotretinoin was used as a maintenance therapy in 4 patients. Five patients had medulloblastoma, 3 had atypical teratoid/rhabdoid tumors, 1 had an embryonal tumor with abundant neuropil and true rosettes, and 1 had pineoblastoma. The median age of the patients was 1.9 years. A total of 19 HDC/ASCR procedures were performed. Radiotherapy (RT) was administered to 5 patients after HDC/ASCR and as a salvage therapy in 1 patient. The progression-free survival rate was 50% at 1 year and at 2 years, with a median follow-up of 24 months. All 5 patients with medulloblastoma are still alive without evidence of disease, but the other patients died secondary to tumor progression. This experience suggests that strategies combining myeloablative chemotherapy and autologous stem cell rescue appear to be feasible for children with embryonal brain tumors in the Middle East.

Clinical characteristics and genetic subtypes of Fanconi anemia in Saudi patients.

We reviewed our institutional experience from 2011 to 2015 on new cases of Fanconi anemia (FA). Ten unrelated cases were diagnosed during this period. Four patients with severe aplastic anemia (SAA) had c.2392C > T (p.Arg798*) BRIP1/FANCJ mutation. Another child with SAA had novel c.1475T > C (p.Leu492Pro) FANCC mutation. One individual with SAA and acute myeloid leukemia had c.637_643del (p.Tyr213Lysfs*6) FANCG mutation. Three patients presented with early onset of cancer, two had BRCA2 mutation c.7007G > A (p.Arg2336His) and one had a novel c.3425del (p.Leu1142Tyrfs*21) PALB2 mutation. Another infant with c.3425del PALB2 mutation had clonal aberration with partial trisomy of the long arm of chromosome 17. Mutations in FA downstream pathway genes are more frequent in our series than expected. Our preliminary observation will be confirmed in a large multi-institutional study.

Hematopoietic stem cell transplantation in the Eastern Mediterranean Region (EMRO) 2011-2012: A comprehensive report on behalf of the Eastern Mediterranean Blood and Marrow Transplantation group (EMBMT).

OBJECTIVE/BACKGROUND: The Eastern Mediterranean Blood and Marrow Transplantation (EMBMT) group has accumulated over 31 years of data and experience in hematopoietic stem cell transplantation (HSCT), particularly in hemoglobinopathies, severe aplastic anemia, inherited metabolic and immune disorders, in addition to a wide array of hematologic malignancies unique to this region. A regional update in current HSCT trends is highly warranted. We studied the trends of HSCT activities in World Health Organization-Eastern Mediterranean (EMRO) region, surveyed by the EMBMT, between 2011 and 2012. METHODS: Retrospective analysis of the survey data mainly of cumulative number of transplants, types of transplants (autologous vs. allogeneic), types of conditioning such as myeloablative versus reduced intensity was conducted. Also, trends in leukemias, hemoglobinopathies, severe aplastic anemia, inherited bone marrow failure syndromes, amongst others were analyzed. RESULTS: Twenty-one teams from nine EMRO countries reported their data (100% return rate) to the EMBMT for the years 2011-2012, with a total of 3,546 first HSCT (1,670 in 2011; 1,876 in 2012). Allogeneic HSCT (allo-HSCT) represented the majority (62%) in both years. The main indications for allo-HSCT were acute leukemias (988; 46%), bone marrow failure syndromes (421, 20%), hemoglobinopathies (242; 11%), and immune deficiencies (157; 7%). There was a progressive increase in the proportions of chronic myeloid leukemia cases transplanted beyond first chronic phase (37 [7%] of all chronic myeloid leukemia cases in 2011 vs. 39 [29%] in 2012). The main indications for autologous transplants were multiple myeloma/plasma cell disorders (510; 39%), Hodgkin lymphoma (311; 24%), non-Hodgkin lymphoma (259; 20%), and solid tumors (163; 12%). Reduced intensity conditioning continued to show a progressive decrease over years (9.5% in 2011 vs. 7.9% in 2012), yet remained relatively low compared with contemporary practices in Europe published by EBMT. The vast majority (91%) of allo-HSCT source was from sibling donors with continued dominance of peripheral blood (64%) followed by bone marrow (33%).While umbilical cord blood transplants increased to 4% of allo-HSCT, matched unrelated donor remained underutilized and there was no haplo-identical transplant reported. Large centers with >50 HSCT/year, showed a continued increase in the total number of allo-HSCT over the past 2years that may be related to capacity building issues and require further studies. CONCLUSION: There is a discernable increase of HSCT rate in the EMRO region with a significant expansion in utilization of cord blood transplants and allogeneic peripheral blood-HSCT as a valuable source. However, further research of outcome data and the development of regional donor banks (cord blood and matched unrelated donors) may help to facilitate future planning to satisfy the escalating regional needs and augment collaboration within the EMBMT and globally.