The outcomes of family haploidentical hematopoietic stem cell transplantation in hematologic malignancies are not associated with patient age

Acute Leukemia Relapse after Hematopoietic Stem Cell Transplantation: The Good, the Bad, and the Ugly of Isolated Extramedullary Relapse in a Latin American Population

Hematopoietic stem cell transplantation (HSCT) is an effective therapy for acute leukemia (AL). Relapse represents the main cause of mortality. Isolated extramedullary relapse (iEMR) is atypical and has been related to better outcomes. Here we describe the clinical characteristics and outcomes of AL relapse after HSCT in our study population and analyze the impacts of different types of relapse on survival outcomes. This retrospective, multicenter study included 124 patients age ≥15 years with AL who underwent HSCT between 2004 and 2019. At diagnosis, 66.1% of the patients had lymphocytic AL, 19.7% presented with high-risk features, and 18.5% had extramedullary disease (EMD). At HSCT, 83.1% of the patients were in complete remission (CR), and 44.8% had negative measurable residual disease (MRD). The vast majority of donors were related (96%), including 48.4% HLA-matched and 47.6% haploidentical. Myeloablative conditioning was provided to 80.6% of patients. The median overall survival (OS) was 15 months (95% confidence interval [CI] 9.9 to 20.1 months). Factors associated with improved OS were adolescent and young adult (AYA) patient (P = .035), first or second CR (P = .026), and chronic graft-versus-host disease (GVHD) (P < .001). Acute GVHD grade III-IV (P = .009) was associated with increased mortality. The median relapse-free survival was 13 months (95% CI, 7.17 to 18.8 months); early disease status (P = .017) and chronic GVHD (P < .001) had protective roles. Sixty-eight patients (55%) relapsed after HSCT, with a median time to relapse of 6 months (95% CI, 3.6 to 8.4 months). iEMR was reported in 16 patients (23.5%). The most commonly involved extramedullary sites were the central nervous system and skin. Compared to patients with bone marrow relapse, all patients with iEMR had a diagnosis of acute lymphoid leukemia (P = .008), and 93.8% belonged to the AYA group; regarding pre-HSCT characteristics, iEMR patients had higher rates of negative MRD (P = .06) and a history of EMD (P = .009). Seventy-seven percent of relapsed patients received additional treatment with curative intent. The median OS after relapse (OSr) was 4 months (95% CI, 2.6 to 5.4 months). Factors related to increased OSr included lymphoid phenotype (P = .03), iEMR (P = .0042), late relapse (≥6 months) (P = .014), receipt of systemic therapy including second HSCT (P < .001), and response to therapy (P < .001). Rates of relapse and iEMR were higher than those previously reported in other studies. Advanced disease, reduced-intensity conditioning, and a diminished graft-versus-leukemia effect were factors influencing these findings. At relapse, presenting with iEMR after 6 months and receiving intensive therapy with adequate response were associated with better outcomes. Our results strongly suggest that a personalized approach to treating patients with HSCT is needed to counterbalance specific adverse factors and can positively impact clinical outcomes.

The Superiority of Allogeneic Hematopoietic Stem Cell Transplantation Over Chemotherapy Alone in the Treatment of Acute Myeloid Leukemia Patients with Mixed Lineage Leukemia (MLL) Rearrangements

BACKGROUND Acute myeloid leukemia (AML) patients with mixed lineage leukemia (MLL) gene rearrangements always had a very poor prognosis. In this study, we report the incidence of MLL rearrangements in AML patients using gene analysis, as well as the clinical significance and prognostic features of these rearrangements. MATERIAL AND METHODS This retrospective study took place from April 2008 to November 2011 in the People's Liberation Army General Hospital. A total 433 AML patients were screened by multiple nested reverse transcription polymerase chain reaction (RT-PCR) to determine the incidence of the 11 MLL gene rearrangements. There were 68 cases of MLL gene rearrangements, for a positive rate of 15.7%. A total of 24 patients underwent allogeneic hematopoietic stem cell transplantation (Allo-HSCT), and 34 patients received at least 4 cycles of chemotherapy. Ten patients were lost to follow-up. RESULTS The median follow-up was 29 months. The complete remission (CR) rate was 85.4%. The overall survival (OS) was 57.4±5.9 months for the Allo-HSCT group and 21.0±2.1 months for the chemotherapy group. The Allo-HSCT group had superior survival compared with the chemotherapy group (5-year OS: 59±17% vs. 13±8%, P<0.01; 5-year disease-free survival [DFS]: 65±10% vs. 40±16%, P>0.05). Multivariate analysis showed that transplantation, platelets >50×10^9/L at onset, and CR are associated with a better OS in MLL rearranged AML patients. Patients with thrombocytopenia and extramedullary involvement were prone to relapse. CONCLUSIONS Our results suggest that Allo-HSCT is superior to chemotherapy alone for treating MLL rearranged AML patients. Patients treated with Allo-HSCT have a better prognosis and a longer survival. CR is an independent prognostic factor for OS, and extramedullary involvement is an independent prognostic factor for DFS. MLL rearranged AML patients with thrombocytopenia at onset <50×10^9 had very bad OS and DFS.

Good outcome of haploidentical hematopoietic SCT as a salvage therapy in children and adolescents with acquired severe aplastic anemia

Haploidentical hematopoietic SCT (haplo-HSCT) is to be established in patients with acquired severe aplastic anemia (SAA) refractory to immunosuppressive therapy and lacking HLA-matched related or unrelated donors. Graft failure (GF) and GVHD have been major obstacles to HSCT. A total of 17 children and adolescents with SAA underwent haplo-HSCT in our center. The conditioning regimen consisted of BU, fludarabine, CY and anti-thymocyte globulin. All patients received cyclosporine, short-term MTX, mycophenolate mofetil and basiliximab for GVHD prophylaxis. Mesenchymal stem cells derived from unrelated umbilical cord were infused on day 1. Neutrophil engraftment was achieved in all 17 patients in a median time of 16 days (range 9-25 days). The median time of platelet engraftment was 22 days (range 9-95 days) in 16 patients. The cumulative incidence (CI) of II-IV acute GVHD (aGVHD) at day +100 was 30.53±11.12% and III-IV aGVHD occurred in only one patient. The CI of chronic GVHD was 21.25±13.31%. Secondary GF with autologous hematopoiesis recovery occurred in one patient. The OS was 71.60±17.00% at a median follow-up of 362 (36-1321) days. These limited promising data suggest that haplo-HSCT is feasible as a salvage therapy for children and adolescents with refractory SAA who lack matched donors.

The superiority of haploidentical related stem cell transplantation over chemotherapy alone as postremission treatment for patients with intermediate- or high-risk acute myeloid leukemia in first complete remission

We report the results of a prospective, patient self-selected study evaluating whether haploidentical related donor stem cell transplantation (HRD-HSCT) is superior to chemotherapy alone as postremission treatment for patients with intermediate- or high-risk acute myeloid leukemia (AML) in first complete remission (CR1). Among totally 419 newly diagnosed AML patients, 132 patients with intermediate- and high-risk cytogenetics achieved CR1 and received chemotherapy alone (n = 74) or HSCT (n = 58) as postremission treatment. The cumulative incidence of relapse at 4 years was 37.5% ± 4.5%. Overall survival (OS) and disease-free survival (DFS) at 4 years were 64.5% ± 5.1% and 55.6% ± 5.0%, respectively. The cumulative incident of relapse for the HRD-HSCT group was significantly lower than that for the chemotherapy-alone group (12.0% ± 4.6% vs 57.8% ± 6.2%, respectively; P < .0001). HRD-HSCT resulted in superior survival compared with chemotherapy alone (4-year DFS, 73.1% ± 7.1% vs 44.2% ± 6.2%, respectively; P < .0001; 4-year OS, 77.5% ± 7.1% vs 54.7% ± 6.3%, respectively; P = .001). Multivariate analysis revealed postremission treatment (HRD-HSCT vs chemotherapy) and high WBC counts at diagnosis as independent risk factors affecting relapse, DFS, and OS. Our results suggest that HRD-HSCT is superior to chemotherapy alone as postremission treatment for AML.