Abstract

NK cells can exert remarkable graft-versus-leukemia (GvL) effect in HLA-haploidentical hematopoietic stem cell transplantation (haplo-HSCT). Here, we dissected the NK-cell repertoire of 80 pediatric acute leukemia patients previously reported to have an excellent clinical outcome after aßT/B-depleted haplo-HSCT. This graft manipulation strategy allows the co-infusion of mature immune cells, mainly NK and ?dT cells, and hematopoietic stem cells (HSCs). To promote NK-cell based antileukemia activity, 36/80 patients were transplanted with an NK alloreactive donor, defined according to the KIR/KIR-Ligand mismatch in the graft-versus-host direction. The analysis of the reconstituted NK-cell repertoire in these patients showed relatively high proportions of mature and functional KIR(+)NKG2A(-)CD57(+) NK cells, including the alloreactive NK cell subset, one month after HSCT. Thus, the NK cells adoptively transfused with the graft persist as a mature source of effector cells while new NK cells differentiate from the donor HSCs. Notably, the alloreactive NK cell subset was endowed with the highest anti-leukemia activity and its size in the reconstituted repertoire could be influenced by human cytomegalovirus (HCMV) reactivation. While the phenotypic pattern of donor NK cells did not impact on post-transplant HCMV reactivation, in the recipients, HCMV infection/reactivation fostered a more differentiated NK-cell phenotype. In this cohort, no significant correlation between differentiated NK cells and relapse-free survival was observed.

Abstract

We have treated 69 patients with steroid refractory acute graft versus host disease (SR-aGvHD), with an anti-CD26 monoclonal antibody (Begelomab): 28 patients in two prospective studies (EudraCT No. 2007-005809-21; EudraCT No. 2012-001353-19), and 41 patients on a compassionate use study. The median age of patients was 42 and 44 years; the severity of GvHD was as follows: grade II in 8 patients, grade III in 33, and grade IV in 28 patients. There were no adverse events directly attributable to the antibody. Day 28 response was 75% in the prospective studies and 61% in the compassionate use patients, with complete response rates of 11 and 12%. Response for grade III GvHD was 83 and 73% in the two groups; response in grade IV GvHD was 66 and 56% in the two groups. Non relapse mortality (NRM) at 6 months was 28 and 38%. Overall there were 64, 56, 68% responses for skin, liver, and gut stage 3-4 GvHD. The overall survival at 1 year was 50% for the prospective studies and 33% for the compassionate use patients. In conclusion, Begelomab induces over 60% responses in SR-aGvHD, including patients with severe gut and liver GvHD, having failed one or more lines of treatment.

Abstract

Allogeneic hematopoietic stem cell transplantation (allo-HSCT) is curative for bone marrow failure in patients with Fanconi anemia (FA), but the presence of a malignant transformation is associated with a poor prognosis and the management of these patients is still challenging. We analyzed outcome of 74 FA patients with a diagnosis of myelodysplastic syndrome (n = 35), acute leukemia (n = 35) or with cytogenetic abnormalities (n = 4), who underwent allo-HSCT from 1999 to 2016 in EBMT network. Type of diagnosis, pre-HSCT cytoreductive therapies and related toxicities, disease status pre-HSCT, donor type, and conditioning regimen were considered as main variables potentially influencing outcome. The 5-year OS and EFS were 42% (30-53%) and 39% (27-51%), respectively. Patients transplanted in CR showed better OS compared with those transplanted in presence of an active malignant disease (OS:71%[48-95] vs 37% [24-50],P = .04), while none of the other variables considered had an impact. Twenty-two patients received pre-HSCT cytoreduction and 9/22 showed a grade 3-4 toxicity, without any lethal event or negative influence on survival after HSCT(OS:toxicity pre-HSCT 48% [20-75%] vs no-toxicity 51% [25-78%],P = .98). The cumulative incidence of day-100 grade II-IV a-GvHD and of 5-year c-GvHD were 38% (26-50%) and 40% (28-52%). Non-relapse-related mortality and incidence of relapse at 5-years were 40% (29-52%) and 21% (11-30%) respectively, without any significant impact of the tested variables. Causes of death were transplant-related events in most patients (34 out of the 42 deaths, 81%). This analysis confirms the poor outcome of transformed FA patients and identifies the importance of achieving CR pre-HSCT, suggesting that, in a newly diagnosed transformed FA patient, a cytoreductive approach pre-HSCT should be considered if a donor have been secured. This article is protected by copyright. All rights reserved.

Abstract

Allogeneic hematopoietic stem cell transplantation (HSCT) is a curative procedure in patients with Shwachman-Diamond syndrome (SDS) with bone marrow abnormalities. The results of 74 patients with SDS (6 acute myeloid leukemia, 7 myelodysplastic syndrome, and 61 bone marrow failure) treated with HSCT between 1988 and 2016 are reported. The donor source was: 24% sibling, 8% parent, and 68% unrelated donor. The stem cell source was: 70% bone marrow, 19% peripheral blood stem cells, and 11% cord blood. The conditioning regimen was myeloablative in 54% and reduced intensity in 46%. Neutrophil engraftment was achieved in 84% of patients after a median time of 17.5 days. Graft failure occurred in 15% of HSCTs. Grades I-IV acute and chronic GVHD were observed in 55% and 20% of patients, respectively. After a median follow-up of 7.3 years (95% CI 4.8-10.2), 28 patients died for progression/relapse (7) or toxicity (21). The 5-year overall survival and nonrelapse mortality were 63.3% (95% CI 50.8-73.4) and 19.8% (95% CI 10.8-30.8), respectively. In conclusion, this is the largest series so far reported and confirms that HSCT is a suitable option for patients with SDS. Further efforts are needed to lower transplant-related toxicity and reduce graft failure.

Abstract

Patients given allogeneic hematopoietic stem cell transplantation (alloHSCT) present an increased incidence of long-term toxicities that can be attributed to the preparative regimen. We retrospectively analyzed in a population of 670 children receiving allo-HSCT for acute leukemia the occurrence of different late effects in function of the choice made between total body irradiation (TBI) and busulfan, as part of the preparative regimen. In univariable analysis, we found that patients treated with TBI developed cataract in 24% of the cases compared with 4% in patients treated with BU (p = 0.0001) and that the incidence of secondary malignant neoplasia (SMN) was higher in patients treated with TBI (18%) as compared with those prepared to the allograft with a Bu-based regimen (0%) (p = 0.019). Conditioning regimen did not show a statistically significant correlation with the occurrence of all the other investigated late effects. In multivariable analysis, TBI remained associated with the occurrence of cataracts (Relative Risk: 0.33 p = 0.012) and secondary malignancies (Relative Risk 3.96 x 10e-6 p < 0.001); however, other variables, as GvHD and disease type, were also correlated with these long-term sequels, indicating that in our study population the preparative regimen is not the only factor influencing the incidence of these complications.

Abstract

Outcome of 333 children with acute myeloid leukaemia relapsing after a first allogeneic haematopoietic stem cell transplantation was analyzed. Four-year probability of overall survival (4y-pOS) was 14%. 4y-pOS for 122 children receiving a second haematopoietic stem cell transplantation was 31% and 3% for those that did not (P = <0.0001). Achievement of a subsequent remission impacted survival (P = <0.0001). For patients receiving a second transplant survival with or without achieving a subsequent remission was comparable. Graft source (bone marrow vs. peripheral blood stem cells, P = 0.046) and donor choice (matched family vs. matched unrelated donor, P = 0.029) positively impacted survival after relapse. Disease recurrence and non-relapse mortality at four years reached 45% and 22%.

Abstract

Although most children with acute lymphoblastic leukemia (ALL) receive fractionated total body irradiation (FTBI) as myeloablative conditioning (MAC) for allogeneic hematopoietic stem cell transplantation (allo-HSCT), it is an important matter of debate if chemotherapy can effectively replace FTBI. To compare outcomes after FTBI versus chemotherapy-based conditioning (CC), we performed a retrospective EBMT registry study. Children aged 2-18 years after MAC for first allo-HSCT of bone marrow (BM) or peripheral blood stem cells (PBSC) from matched-related (MRD) or unrelated donors (UD) in first (CR1) or second remission (CR2) between 2000 and 2012 were included. Propensity score weighting was used to control pretreatment imbalances of the observed variables. 3.054 patients were analyzed. CR1 (1.498): median follow-up (FU) after FTBI (1.285) and CC (213) was 6.8 and 6.1 years. Survivals were not significantly different. CR2 (1.556): median FU after FTBI (1.345) and CC (211) was 6.2 years. Outcomes after FTBI were superior as compared with CC with regard to overall survival (OS), leukemia-free survival (LFS), relapse incidence (RI), and nonrelapse mortality (NRM). However, we must emphasize the preliminary character of the results of this retrospective "real-world-practice" study. These findings will be prospectively assessed in the ALL SCTped 2012 FORUM trial.

Abstract

TcRalphabeta/CD19-cell depleted HLA-haploidentical hematopoietic stem cell transplantation (haplo-HSCT) represents a promising new platform for children affected by acute leukemia in need of an allograft and lacking a matched donor, disease recurrence being the main cause of treatment failure. The use of zoledronic acid to enhance TcRgammadelta+ lymphocyte function after TcRalphabeta/CD19-cell depleted haplo-HSCT was tested in an open-label, feasibility, proof-of-principle study. Forty-six children affected by high-risk acute leukemia underwent haplo-HSCT after removal of TcRalphabeta+ and CD19+ B lymphocytes. No post-transplant pharmacological graft-versus-host disease (GvHD) prophylaxis was given. Zoledronic acid was administered monthly at a dose of 0.05 mg/kg/dose (maximum dose 4 mg), starting from day +20 after transplantation. A total of 139 infusions were administered, with a mean of 3 infusions per patient. No severe adverse event was observed. Common side effects were represented by asymptomatic hypocalcemia and acute phase reactions (including fever, chills, malaise, and/or arthralgia) within 24-48 h from zoledronic acid infusion. The cumulative incidence of acute and chronic GvHD was 17.3% (all grade I-II) and 4.8% (all limited), respectively. Patients given 3 or more infusions of zoledronic acid had a lower incidence of both acute GvHD (8.8 vs. 41.6%, p = 0.015) and chronic GvHD (0 vs. 22.2%, p = 0.006). Transplant-related mortality (TRM) and relapse incidence at 3 years were 4.3 and 30.4%, respectively. Patients receiving repeated infusions of zoledronic acid had a lower TRM as compared to those receiving 1 or 2 administration of the drug (0 vs. 16.7%, p = 0.01). Five-year overall survival (OS) and disease-free survival (DFS) for the whole cohort were 67.2 and 65.2%, respectively, with a trend toward a better OS for patients receiving 3 or more infusions (73.1 vs. 50.0%, p = 0.05). The probability of GvHD/relapse-free survival was significantly worse in patients receiving 1-2 infusions of zoledonic acid than in those given ≥3 infusions (33.3 vs. 70.6%, respectively, p = 0.006). Multivariable analysis showed an independent positive effect on outcome given by repeated infusions of zoledronic acid (HR 0.27, p = 0.03). These data indicate that the use of zoledronic acid after TcRalphabeta/CD19-cell depleted haploHSCT is safe and may result in a lower incidence of acute GvHD, chronic GvHD, and TRM.

Abstract

PURPOSE Total body irradiation (TBI) before allogeneic hematopoietic stem cell transplantation (HSCT) in pediatric patients with acute lymphoblastic leukemia (ALL) is efficacious, but long-term side effects are concerning. We investigated whether preparative combination chemotherapy could replace TBI in such patients. PATIENTS AND METHODS FORUM is a randomized, controlled, open-label, international, multicenter, phase III, noninferiority study. Patients = 18 years at diagnosis, 4-21 years at HSCT, in complete remission pre-HSCT, and with an HLA-compatible related or unrelated donor were randomly assigned to myeloablative conditioning with fractionated 12 Gy TBI and etoposide versus fludarabine, thiotepa, and either busulfan or treosulfan. The noninferiority margin was 8%. With 1,000 patients randomly assigned in 5 years, 2-year minimum follow-up, and one-sided alpha of 5%, 80% power was calculated. A futility stopping rule would halt random assignment if chemoconditioning was significantly inferior to TBI (EudraCT: 2012-003032-22; ClinicalTrials.gov: NCT01949129). RESULTS Between April 2013 and December 2018, 543 patients were screened, 417 were randomly assigned, 212 received TBI, and 201 received chemoconditioning. The stopping rule was applied on March 31, 2019. The median follow-up was 2.1 years. In the intention-to-treat population, 2-year overall survival (OS) was significantly higher following TBI (0.91; 95% CI, 0.86 to 0.95; P < .0001) versus chemoconditioning (0.75; 95% CI, 0.67 to 0.81). Two-year cumulative incidence of relapse and treatment-related mortality were 0.12 (95% CI, 0.08 to 0.17; P < .0001) and 0.02 (95% CI, < 0.01 to 0.05; P = .0269) following TBI and 0.33 (95% CI, 0.25 to 0.40) and 0.09 (95% CI, 0.05 to 0.14) following chemoconditioning, respectively. CONCLUSION Improved OS and lower relapse risk were observed following TBI plus etoposide compared with chemoconditioning. We therefore recommend TBI plus etoposide for patients > 4 years old with high-risk ALL undergoing allogeneic HSCT.