Matched-related allogeneic stem cell transplantation in Saudi patients with Fanconi anemia: 10 year's experience

Fludarabine-Based Low-Intensity Conditioning for Fanconi Anemia is Associated with Good Outcomes in Aplastic Anemia but not in MDS - a Single-Center Experience

Background

Hematopoietic stem cell transplantation (HSCT) is the only curative option for patients with Fanconi Anemia (FA) with hematological abnormalities.

Materials and Methods

This is a retrospective analysis of patients with FA who underwent a matched-related donor HSCT.

Results

Sixty patients underwent 65 transplants between 1999-2021 using a fludarabine-based low-intensity conditioning regimen. The median age at transplant was 11 years (range: 3-37). Aplastic anemia (AA) was the underlying diagnosis in 55 (84.6%), while 8 (12.4%) had myelodysplastic syndrome (MDS) and 2 (3%) had acute myeloid leukemia (AML). The conditioning regimen used was Fludarabine with low-dose Cyclophosphamide for aplastic anemia and Fludarabine with low-dose Busulfan for MDS/AML. Graft versus host disease (GVHD) prophylaxis consisted of Cyclosporine and methotrexate. Peripheral blood was the predominant stem cell graft source (86.2%). Engraftment occurred in all but one patient. The median time to neutrophil and platelet engraftment was 13 days (range: 9-29) & 13 days (range: 5-31), respectively. Day 28 chimerism analysis showed complete chimerism in 75.4 % and mixed chimerism in 18.5%. Secondary graft failure was encountered in 7.7%. Grade II-IV acute GVHD occurred in 29.2%, while Grade III-IV acute GVHD occurred in 9.2%. Chronic GVHD was seen in 58.5% and was limited in most patients. The median follow-up is 55 months (range: 2-144) & the 5-year estimated overall survival (OS) is 80.2 ± 5.1%. Secondary malignancies were noted in 4 patients. The 5-year OS was significantly higher in patients undergoing HSCT for AA (86.6 + 4.7%) as compared to MDS/AML (45.7+16.6%) (p= 0.001).

Conclusion

SCT using a fully matched donor provides good outcomes with low-intensity conditioning regimens in patients with FA who have aplastic marrow.

Unmanipulated haploidentical haematopoietic cell transplantation with radiation-free conditioning in Fanconi anaemia: A retrospective analysis from the Chinese Blood and Marrow Transplantation Registry Group

Haematopoietic cell transplantation (HCT) is the only curative treatment for haematological complications in patients with Fanconi anaemia (FA). Haploidentical (haplo-) HCT is a promising alternative for FA. We aimed to analyse the outcomes of unmanipulated haplo-HCT in patients with FA with radiation-free conditioning. A total of 56 patients from 11 centres between 2013 and 2021 in China were retrospectively analysed. The mean (SD) cumulative incidence was 96.4% (0.08%) for 30-day neutrophil engraftment and 85.5% (0.24%) for 100-day platelet engraftment. With a median (range) follow-up of 2.4 (0.2-5.8) years, favourable mean (SD) overall survival of 80.9% (5.5%) and event-free survival of 79.3% (5.6%) were achieved. The mean (SD) incidences of acute graft-versus-host disease (aGvHD) Grade II-IV and Grade III-IV were 55.4% (0.45%) and 42.9 (0.45%) respectively. The mean (SD) cumulative incidence of 3-year chronic graft-versus-host disease (cGvHD) was 34.7% (0.86%) and that of moderate-to-severe cGvHD was 9.0% (0.19%). Our data demonstrate that in unmanipulated haplo-HCT for patients with FA, radiation-free regimens based on fludarabine and low-dose cyclophosphamide ± busulfan achieved favourable engraftment and survival with relatively high incidences of aGvHD and cGvHD. These results prompt the use of low-intensity conditioning without radiation and intensive GvHD prophylaxis when considering unmanipulated haplo-HCT in patients with FA.

Bone Marrow Failure in Fanconi Anemia: Clinical and Genetic Spectrum in a Cohort of 20 Pediatric Patients

Prognostic refinement in Fanconi anemia (FA) is needed, especially when considering allogeneic hematopoietic stem cell transplantation (HCT). We studied 20 children with FA and bone marrow failure from a single center. According to Hôpital Saint-Louis risk classification for FA, patients were classified in stage A (no or mild cytopenia/dysplasia), B (single non-high-risk cytogenetic abnormality), C (severe cytopenia and/or significant dysplasia and/or high-risk cytogenetic abnormality), and D (myelodysplastic syndrome with excess of blasts/acute myeloid leukemia) in 4, 2, 13, and 0 cases, respectively. Nine patients received androgens +/- steroids, with a response rate of 30%, and 11 patients underwent HCT. Ten-year cumulative incidence (CI) of myelodysplastic syndrome/acute myeloid leukemia and overall survival (OS) were 21.9% and 45.3%, respectively, in the entire cohort, whereas cumulative incidence of transplantation-related mortality and OS were 27% and 63%, respectively, in patients who underwent HCT. Patients with significant dysplasia at diagnosis (stages C and D) had significantly shorter OS post-HCT as compared with patients without dysplasia. All patients in stages C and D at diagnosis or during evolution died from their disease. HCT in recent years was associated with more favorable outcomes. Larger cohorts could validate homogenous reporting of risk and help decision-making, particularly for HCT.

First report of pediatric hematopoietic stem cell transplantation activities in the eastern mediterranean region from 1984 to 2011: on behalf of the pediatric cancer working committee of the eastern mediterranean blood and marrow transplantation group

To describe the hematopoietic stem cell transplantation (HSCT) activities for children in the Eastern Mediterranean (EM) region, data on transplants performed for children less than 18 years of age between 1984 and 2011 in eight EM countries (Egypt, Iran, Jordan, Lebanon, Oman, Pakistan, Saudi Arabia and Tunisia) were collected. A total of 5187 transplants were performed, of which 4513 (87%) were allogeneic and 674 (13%) were autologous. Overall, the indications for transplantation were malignant diseases in 1736 (38.5%) and non-malignant in 2777 (61.5%) patients. A myeloablative conditioning regimen was used in 88% of the allografts. Bone marrow (BM) was the most frequent source of stem cells (56.2%), although an increasing use of PBSC was observed in the last decade. The stem cell source of autologous HSCT has shifted over time from BM to PBSC, and 80.9% of autologous HSCTs were from PBSCs. The donors for allogeneic transplants were matched-related in 94.5% of the cases, and unrelated transplants, mainly cord blood (99%) in 239 (5.5%) cases. This is the first report to describe the pediatric HSCT activities in EM countries. Non-malignant disorders are the main indication for allogeneic transplantation. Frequency of alternate donor transplantation is low.

Fanconi Anemia: Overview of the Disease and the Role of Hematopoietic Transplantation

Fanconi anemia (FA) is an inherited bone marrow failure syndrome characterized by congenital abnormalities and chromosomal breakages with the occurrence of hematological and solid malignancies. FA is the most common type of inherited bone marrow failure and poses tremendous challenges. FA patients are uniquely hypersensitive to hematopoietic stem cell transplantation (HSCT) conditioning agents due to the underling chromosomal instability. HSCT has shown important progress in the last years, especially after the introduction of fludarabine and the reduction of cyclophosphamide in the preparative regimen. For patients with HLA-identical-related donors HSCT should be performed as first-line therapy, for patients with alternative donors HSCT remains a therapy with increased morbidity and mortality.

Outcomes of mismatched and unrelated donor hematopoietic stem cell transplantation in Fanconi anemia conditioned with chemotherapy only

Fanconi anemia (FA) is a genomic instability syndrome associated with bone marrow failure, myelodysplastic syndrome (MDS), and/or acute myeloid leukemia (AML) requiring hematopoietic stem cell transplantation (HSCT) to restore normal hematopoiesis. Although low-intensity fludarabine-based preparative regimens without radiation confer excellent outcomes in FA HSCTs with HLA-matched sibling donors, outcomes for FA patients with alternative donors are less encouraging, albeit improving. We present our experience with 17 FA patients who completed mismatched related or unrelated donor HSCT using a non-radiation fludarabine-based preparative regimen at Charité University Medicine Berlin. All patients engrafted; however, one patient had unstable chimerism in the setting of multi-viral infections that necessitated a stem cell boost to revert to full donor chimerism. Forty-seven percent of patients developed grade I acute graft-verus-host disease (aGVHD). No grade II-IV aGVHD or chronic graft-versus-host disease of any severity occurred. At a median follow-up of 30 months, 88 % of patients are alive with normal hematopoiesis. Two patients died of infections 4 months post-transplantation. These results demonstrate that short-term outcomes for FA patients with mismatched and unrelated donor HSCTs can be excellent using chemotherapy only conditioning. Viral reactivation, however, was a major treatment-related complication.

Allogeneic hematopoietic cell transplantation for fanconi anemia in patients with pretransplantation cytogenetic abnormalities, myelodysplastic syndrome, or acute leukemia

PURPOSE

Allogeneic hematopoietic cell transplantation (HCT) can cure bone marrow failure in patients with Fanconi anemia (FA). Data on outcomes in patients with pretransplantation cytogenetic abnormalities, myelodysplastic syndrome (MDS), or acute leukemia have not been separately analyzed.

PATIENTS AND METHODS

We analyzed data on 113 patients with FA with cytogenetic abnormalities (n = 54), MDS (n = 45), or acute leukemia (n = 14) who were reported to the Center for International Blood and Marrow Transplant Research from 1985 to 2007.

RESULTS

Neutrophil recovery occurred in 78% and 85% of patients at days 28 and 100, respectively. Day 100 cumulative incidences of acute graft-versus-host disease grades B to D and C to D were 26% (95% CI, 19% to 35%) and 12% (95% CI, 7% to 19%), respectively. Survival probabilities at 1, 3, and 5 years were 64% (95% CI, 55% to 73%), 58% (95% CI, 48% to 67%), and 55% (95% CI, 45% to 64%), respectively. In univariate analysis, younger age was associated with superior 5-year survival (≤ v > 14 years: 69% [95% CI, 57% to 80%] v 39% [95% CI, 26% to 53%], respectively; P = .001). In transplantations from HLA-matched related donors (n = 82), younger patients (≤ v > 14 years: 78% [95% CI, 64% to 90%] v 34% [95% CI, 20% to 50%], respectively; P < .001) and patients with cytogenetic abnormalities only versus MDS/acute leukemia (67% [95% CI, 52% to 81%] v 43% [95% CI, 27% to 59%], respectively; P = .03) had superior 5-year survival.

CONCLUSION

Our analysis indicates that long-term survival for patients with FA with cytogenetic abnormalities, MDS, or acute leukemia is achievable. Younger patients and recipients of HLA-matched related donor transplantations who have cytogenetic abnormalities only have the best survival.

Matched sibling donor stem cell transplantation for Fanconi anemia patients with T-cell somatic mosaicism

SCT from HLA-identical sibling donors is generally associated with an excellent survival in FA patients if performed prior to the development of MDS or leukemia. However, the optimal conditioning regimen has not been defined. We report here our experience with 15 Japanese FA patients who underwent HLA-matched sibling donor SCT. The aim of this study is to compare radiation-based conditioning to Flu-based conditioning for FA patients in a Japanese population where the T-cell somatic mosaicism is higher than in the Caucasian population. Eight patients (a-group) received a radiation-based conditioning (500-600 cGy of thoracoabdominal/TBI) with CY dose modification (20-120 mg/kg), and ATG; two patients exhibited rejection. Seven patients (b-group) received CY (40 mg/kg), 150-180 mg/m(2) of Flu, and ATG. Durable engraftment was demonstrated in all patients. In FA patients, Flu-based conditioning may allow stable engraftment in matched sibling donor transplantation without radiation, even in patients with T-cell somatic mosaicism.

Trends of hematopoietic stem cell transplantation in the Eastern Mediterranean region, 1984-2007

Hematopoietic stem cell transplantation (HSCT) activity was surveyed in the 9 countries in the World Health Organization Eastern Mediterranean region that reported transplantation activity. Between the years of 1984 and 2007, 7933 transplantations were performed. The number of HSCTs per year has continued to increase, with a plateau in allogeneic HSCT (allo-HSCT) between 2005 and 2007. Overall, a greater proportion of transplantations were allo-HSCT (n = 5761, 77%) compared with autologous HSCT (ASCT) (n = 2172, 23%). Of 5761 allo-HSCT, acute leukemia constituted the main indication (n = 2124, 37%). There was a significant proportion of allo-HSCT for bone marrow failures (n = 1001, 17%) and hemoglobinopathies (n = 885, 15%). The rate of unrelated donor transplantations remained low, with only 2 matched unrelated donor allo-HSCTs reported. One hundred umbilical cord blood transplantations were reported (0.017% of allo-HSCT). Peripheral blood stem cells were the main source of graft in allo-HSCT, and peripheral blood stem cells increasingly constitute the main source of hematopoietic stem cells overall. Reduced-intensity conditioning was utilized in 5.7% of allografts over the surveyed period. ASCT numbers continue to increase. There has been a shift in the indication for ASCT from acute leukemia to lymphoproliferative disorders (45%), followed by myeloma (26%). The survey reflects transplantation activity according to the unique health settings of this region. Notable differences in transplantation practices as reported to the European Group for Blood and Marrow Transplantation over recent years are highlighted.

Fanconi anemia - learning from children

Fanconi Anemia (FA) is a rare autosomic recessive and X-linked disease with chromosomal instability after exposure to crosslinking agents as the hallmark. Clinical features of FA are somatic malformations, progressive bone marrow failure and cancer proneness, however there is wide clinical heterogeneity. The symptom most frequently and early associated with morbidity and mortality is progressive pancytopenia in the first decade of life although acute myelogenous leukemia (AML) or myelodysplastic syndrome (MDS) can appear before aplastic anemia. Squamous cell carcinoma (SCC) of the head-neck, intestinal or genital tract has a very high incidence in FA and can appear at young age. This paper will focus on treatment of bone marrow failure in FA.

Cellular therapy for fanconi anemia: the past, present, and future

Allogeneic hematopoietic cell transplantation (HCT) remains the only proven curative therapy for the hematologic manifestation of Fanconi anemia (FA). Over the past 2 decades, major advances have been made such that transplant outcomes have markedly improved. With the development of in vitro fertilization and preimplantation genetic diagnosis, HLA-matched sibling donor umbilical blood transplantation may be an option for more patients with FA. Recently, the use of pluripotent stem cells has been explored as a novel approach to model the hematopoietic developmental defects in FA, and to provide a potential source of autologous stem cells that can be genetically manipulated and used to generate corrected hematopoietic progenitors.

Haematopoeitic cell transplantation for Fanconi anaemia - when and how?

Allogeneic haematopoietic cell transplantation (HCT) remains the only treatment that can correct the haematological manifestations in patients with Fanconi anaemia. Over the last two decades, sequential changes to the approach to HCT have resulted in reduced regimen-related toxicity, superior engraftment and less graft-versus-host disease (GVHD), resulting in improved survival. The two pivotal changes that most influenced these improvements were the addition of fludarabine to the preparative regimen to augment engraftment, and the use of T cell depletion to reduce GVHD. With these improved HCT outcomes, indications for HCT are quite consistent regardless of donor source. Emphasis is now being placed on developing HCT regimens that will improve quality of life by reducing late effects, particularly the risk of malignancy, sterility and endocrinopathies. This paper will review the unique challenges of HCT in FA patients, with particular emphasis on the timing and approach to HCT.

Bone marrow transplantation for inherited bone marrow failure syndromes

The inherited bone marrow failure (BMF) syndromes are characterized by impaired hematopoiesis and cancer predisposition. Most inherited BMF syndromes are also associated with a range of congenital anomalies. Progress in improving the outcomes for children with inherited BMF syndromes has been limited by the rarity of these disorders, as well as disease-specific genetic, molecular, cellular, and clinical characteristics that increase the risks of complications associated with hematopoietic stem cell transplantation (HSCT). As a result, the ability to develop innovative transplant approaches to circumvent these problems has been limited. Recent progress has been made, as best evidenced in studies adding fludarabine to the preparative regimen for children undergoing unrelated donor HSCT for Fanconi anemia. The rarity of these diseases coupled with the far more likely incremental improvements that will result from ongoing research will require prospective international clinical trials to improve the outcome for these children.

Hematopoietic stem cell transplantation for bone marrow failure syndromes in children

Bone marrow failure (BMF) syndromes include a broad group of diseases of varying etiologies, in which hematopoeisis is abnormal or completely arrested in one or more cell lines. BMF can be an acquired aplastic anemia (AA) or can be congenital, as part of such syndromes as Fanconi anemia (FA), Diamond Blackfan anemia, and Schwachman Diamond syndrome (SDS). In this review, we first address the evolution and current status of bone marrow transplantation (BMT) in the pediatric population in the most common form of BMF, acquired AA. We then discuss pediatric BMT in some of the more common inherited BMF syndromes, with emphasis on FA, in which experience is greatest. It is important to consider the possibility of a congenital etiology in every child (and adult) with marrow failure, because identification of an associated syndrome provides insight into the likely natural history of the disease, as well as prognosis, treatment options for the patient and family, and long-term sequelae both of the disease itself and its treatment.

Better posttransplant outcome with fludarabine based conditioning in multitransfused fanconi anemia patients who underwent peripheral blood stem cell transplantation

Several investigators have been looking for less toxic conditioning regimen for stem cell transplantation in Fanconi anemia (FA) patients because of sensitivity to DNA cross-linking agents and tendency to malignancy. We report 16 multitransfused FA patients who underwent peripheral stem cell transplantation from 13 related and 3 unrelated donors. Although the first 6 patients received thoraco-abdominal irradiation + cyclophosphamide + antithymocyte globulin (regimen A) for conditioning, fludarabine (FLU) + cyclophosphamide + antithymocyte globulin (regimen B) were used in the last 10 patients in which 3 of them received unrelated graft. Cyclosporin A was given alone for the related allografts but also included mycophenolate mofetil for the unrelated allograft as graft versus host disease prophylaxis. We observed a lower risk of peritransplant morbidity and mortality with fewer and milder graft versus host disease in FLU based group. We lost 3 patients in regimen A group and 1 of them from secondary acute myeloid leukemia. Three patients are alive with transfusion independent. In regimen B group, 9 of 10 patients are alive with normal hematologic parameters and full donor chimerism. The longest follow-up durations are 90 and 60 months in regimen A and B, respectively. In conclusion, FLU based conditioning is more effective and successful with lower toxicity in multitransfused FA patients. However, it needs more experience and longer follow up duration.