The 2010 and 2017 editions of the European LeukemiaNet (ELN) recommendations for diagnosis and management of acute myeloid leukemia (AML) in adults are widely recognized among physicians and investigators. There have been major advances in our understanding of AML, including new knowledge about the molecular pathogenesis of AML, leading to an update of the disease classification, technological progress in genomic diagnostics and assessment of measurable residual disease, and the successful development of new therapeutic agents, such as FLT3, IDH1, IDH2, and BCL2 inhibitors. These advances have prompted this update which includes a revised ELN genetic risk classification, revised response criteria, and treatment recommendations.

Although nonmyeloablative conditioning regimen transplantations (NMTs) induce engraftment of allogeneic stem cells with a low spectrum of toxicity, graft-versushost disease (GVHD) remains a significant cause of morbidity and mortality. In vivo T-cell depletion, using alemtuzumab, has been shown to reduce the incidence of GVHD. However, this type of maneuver, although reducing GVHD, may have an adverse impact on disease response, because NMTs exhibit their antitumor activity by relying on a graft-versus-malignancy effect. To explore the efficacy of alemtuzumab compared with methotrexate (MTX) for GVHD prophylaxis, we have compared the results in 129 recipients of a sibling NMT enrolled in 2 prospective studies for chronic lymphoproliferative disorders. Both NMTs were based on the same combination of fludarabine and melphalan, but the United Kingdom regimen (group A) used cyclosporin A plus alemtuzumab, whereas the Spanish regimen (group B) used cyclosporin A plus MTX for GVHD prophylaxis. Patients receiving alemtuzumab had a higher incidence of cytomegalovirus (CMV) reactivation (85% versus 24%, P < .001) and a significantly lower incidence of acute GVHD (21.7% versus 45.1%, P ‫؍‬ .006) and chronic GVHD (5% versus 66.7%, P < .001). Twenty-one percent of patients in group A and 67.5% in group B had complete or partial responses 3 months after transplantation (P < .001). Eighteen patients in group A received donor lymphocyte infusions (DLIs) to achieve disease control.At last follow-up there was no difference in disease status between the groups with 71% versus 67.5% (P ‫؍‬ .43) of patients showing complete or partial responses in groups A and B, respectively. No significant differences were observed in event-free or overall survival between the 2 groups. In conclusion, alemtuzumab significantly reduced GVHD but its use was associated with a higher incidence of CMV reactivation. Patients receiving alemtuzumab often required DLIs to achieve similar tumor control but the incidence of GVHD was not significantly increased after DLI. (Blood. 2002;100: 3121-3127)

FMS-like tyrosine kinase 3 (FLT3) is a transmembrane protein expressed on normal hematopoietic stem and progenitor cells (HSC) and retained on malignant blasts in acute myeloid leukemia (AML). We engineered CD8 and CD4 T-cells expressing a FLT3-specific chimeric antigen receptor (CAR) and demonstrate they confer potent reactivity against AML cell lines and primary AML blasts that express either wild-type FLT3 or FLT3 with internal tandem duplication (FLT3-ITD). We also show that treatment with the FLT3-inhibitor crenolanib leads to increased surface expression of FLT3 specifically on FLT3-ITD AML cells and consecutively, enhanced recognition by FLT3-CAR T-cells in vitro and in vivo. As anticipated, we found that FLT3-CAR T-cells recognize normal HSCs in vitro and in vivo, and disrupt normal hematopoiesis in colony-formation assays, suggesting that adoptive therapy with FLT3-CAR T-cells will require subsequent CAR T-cell depletion and allogeneic HSC transplantation to reconstitute the hematopoietic system. Collectively, our data establish FLT3 as a novel CAR target in AML with particular relevance in high-risk FLT3-ITD AML. Further, our data provide the first proof-of-concept that CAR T-cell immunotherapy and small molecule inhibition can be used synergistically, as exemplified by our data showing superior antileukemia efficacy of FLT3-CAR T-cells in combination with crenolanib.

BackgroundAlthough Hodgkin's lymphoma is a highly curable disease with modern chemotherapy protocols, some patients are primary refractory or relapse after first-line chemotherapy or even after high-dose therapy and autologous stem cell transplantation. We investigated the potential role of allogeneic stem cell transplantation in this setting. Design and MethodsIn this phase II study 92 patients with relapsed Hodgkin's lymphoma and an HLA-identical sibling, a matched unrelated donor or a one antigen mismatched, unrelated donor were treated with salvage chemotherapy followed by reduced intensity allogeneic transplantation. Fourteen patients showed refractory disease and died from progressive lymphoma with a median overall survival after trial entry of 10 months (range, 6-17). Seventy-eight patients proceeded to allograft (unrelated donors, n=23). Fifty were allografted in complete or partial remission and 28 in stable disease. Fludarabine (150 mg/m 2 iv) and melphalan (140 mg/m 2 iv) were used as the conditioning regimen. Anti-thymocyte globulin was additionally used as graft-versus-host-disease prophylaxis for recipients of grafts from unrelated donors. ResultsThe non-relapse mortality rate was 8% at 100 days and 15% at 1 year. Relapse was the major cause of failure. The progression-free survival rate was 47% at 1 year and 18% at 4 years from trial entry. For the allografted population, the progression-free survival rate was 48% at 1 year and 24% at 4 years. Chronic graft-versus-host disease was associated with a lower incidence of relapse. Patients allografted in complete remission had a significantly better outcome. The overall survival rate was 71% at 1 year and 43% at 4 years. ConclusionsAllogeneic stem cell transplantation can result in long-term progression-free survival in heavily pre-treated patients with Hodgkin's lymphoma. The reduced intensity conditioning approach significantly reduced non-relapse mortality; the high relapse rate represents the major remaining challenge in this setting. Blood and Marrow Transplantation. Haematologica 2012;97(2):310-317. doi:10.3324/haematol.2011 . Allogeneic stem cell transplantation after reduced intensity conditioning in patients with relapsed or refractory Hodgkin's lymphoma. Results of the HDR-ALLO study -a prospective clinical trial by the Grupo Español de Linfomas/ Trasplante de Médula Osea (GEL/TAMO) and the Lymphoma Working Party of the European Group for

We analyzed the impact of CD34 ؉ cell dose on the outcome of 86 patients undergoing reduced-intensity conditioning (RIC) allogeneic peripheral blood stem cell transplantation.

SummaryThe graft‐versus‐host disease (GVHD) characteristics of 150 consecutive patients undergoing reduced intensity conditioning allogeneic (allo‐RIC) transplants and 88 patients undergoing myeloablative conditioning regimen were analysed. All patients received the same GVHD prophylaxis and peripheral blood stem cells from a human leucocyte antigen identical sibling. The cumulative incidence of acute GVHD (aGVHD) was 67% and 44% in the myeloablative and allo‐RIC regimen groups, respectively (P < 0·001), and was 39% vs. 29%, respectively (P = 0·043), for grades 2–4 aGVHD. Only conditioning type (myeloablative versus allo‐RIC) significantly influenced the incidence of aGVHD in multivariate analysis: Hazard ratio (HR) = 2·16 [95% confidence interval (CI): 1·52–3·07], P < 0·0001. The cumulative incidence of chronic GVHD (cGVHD) was 63% and 71% among myeloablative and allo‐RIC patients respectively (P = 0·084). This trend was because of the higher incidence of limited cGVHD, but not extensive cGVHD among allo‐RIC recipients [HR = 3·3 (95% CI: 1·42–8·08), P = 0·0017]. Moreover, among patients who developed cGVHD, the cumulative incidence of limited cGVHD was significantly lower in the myeloablative group than in the allo‐RIC group (7% vs. 25%, P = 0·007). Duration of immunosuppression was shorter among allo‐RIC patients (35·5% vs. 68·8% required systemic immunosuppression 36 months after transplant, P = 0·028). Although prospective controlled trials are required to further evaluate the effect of the conditioning regimen on GVHD, our results suggest that RIC modifies the incidence and characteristics of both acute and cGVHD after allogeneic transplantation, and decreases the immunosuppression requirements in long‐term follow up when compared with myeloablative conditioning.

Summary. The outcome of 29 multiple myeloma patients receiving fludarabine and melphalan-based non-myeloablative allogeneic transplant (NMT) was evaluated. Eventfree survival (EFS) at 24 months was 33%, being significantly higher for patients who developed chronic graft-versus-host disease (cGVHD) when compared with those who did not [51% vs 0% respectively, P ¼ 0AE02; hazard rate ¼ 3AE16 (95% confidence interval ¼ 1AE09-9AE15, P ¼ 0AE03)] as well as for patients transplanted in complete remission/partial response (CR/PR) or stable disease (SD), compared with those with refractory/progressive disease (43% vs 0% respectively, P ¼ 0AE02). Overall survival (OS) at 24 months was 60% [72% vs 42% for patients who did and did not develop cGVHD respectively (P ¼ 0AE1); 63% vs 41% for patients in CR/PR or SD vs refractory/progressive disease at transplant respectively (P ¼ 0AE013)]. At a median follow-up of 366 d, 13 patients remained in CR/PR (45% overall response rate). Nine patients have died, three of them as a result of disease progression and six (21%) as a result of transplant-related mortality (TRM). Actuarial incidence of TRM was 37% for patients who developed acute GVHD vs 13% for those who did not (log rank, P ¼ 0AE04). The present study suggests that graft-versus-myeloma effect is the main weapon for disease control after NMT in MM patients and the efficacy of this immune effect depends on tumour burden before transplant.

Summary:We have performed a prospective study to evaluate early chimerism and its kinetics after allogeneic peripheral blood stem cell transplantation among 68 patients who received a reduced-intensity conditioning (RIC) regimen with fludarabine plus melphalan (n ¼ 40) or busulphan (n ¼ 28). Chimerism was analyzed by polymerase chain reaction amplification of short tandem repeats in unfractionated (UF) and/or fractionated nucleated cells from bone marrow and peripheral blood (PB). All of the patients showed initial donor engraftment and no patient presented primary or secondary graft failure. In UF samples, the probability of achieving stable complete donor chimerism (CDC) in PB within the first 6 months was 70% on day +30, 85% on day +100 and 95% on day +180. CDC in granulocytes was observed in nearly all cases from day +30 onwards. CDC in T cells, however, differed among melphalan and busulphan recipients during the first 3 months (100 vs 0% on day +30 and 93 vs 20% on day +90, respectively). In multivariate analysis, the only significant variable associated with the achievement of early CDC was having received more than two lines of chemotherapy pretransplant (Po0.02). No correlation was found between the rate of achieving early CDC and the occurrence of acute graft-versus-host disease (GVHD) or disease progression post-transplant. In multivariate analysis, the only variable that influenced the incidence of disease progression posttransplant was the development of chronic extensive GVHD (Po0.05). In conclusion, a state of CDC is readily obtained within the first 6 months after our RIC protocols. Donor myeloid engraftment occurs rapidly in all cases, while early T-cell CDC is more common in more immunosuppressed hosts and, perhaps, in melphalan recipients.