[The present and future of haploidentical hematopoietic stem cell transplantation in China].

The lack of donors is the biggest obstacle to the widespread use of hematopoietic stem cell transplantation. The establishment and improvement of new transplantation schemes have made haploid hematopoietic stem cell transplantation a clinical routine, benefiting a large number of patients with hematological diseases. Haploid donors have become the most important source of donors for allogeneic hematopoietic stem cell transplantation in China. This article focuses on the current situation and future development trends of haploid hematopoietic stem cell transplantation in China, in order to increase the understanding of clinical doctors on haploid hematopoietic stem cell transplantation.

Ruxolitinib is an effective salvage treatment for multidrug-resistant graft-versus-host disease after haploidentical allogeneic hematopoietic stem cell transplantation without posttransplant cyclophosphamide.

The purpose of our study is to identify the efficacy of ruxolitinib in human leukocyte antigen (HLA) haploidentical hematopoietic stem cell transplantation (haplo-HSCT) recipients with multidrug-resistant (MDR)-graft-versus-host disease (GVHD, n = 34). MDR-GVHD was defined as GVHD showing no improvement after at least 3 types of treatments. The median number of previous GVHD-therapies was 4 for both MDR-acute GVHD (aGVHD) and MDR-chronic GVHD (cGVHD). For MDR-aGVHD (n = 15), the median time to response was 10 days (range 2 to 65), and the overall response rate (ORR) was 60.0% (9/15), including 40.0% (6/15) complete response (CR) and 20.0% (3/15) partial response (PR). The 1-year probability of overall survival after ruxolitinib was 66.7%. The rates of hematologic and infectious toxicities were 73.3% and 46.7% after ruxolitinib treatment. For MDR-cGVHD (n = 19), the median time to response was 29 days (range 6 to 175), and the ORR was 89.5% (17/19), including 26.3% (5/19) CR and 63.2% (12/19) PR. All patients remained alive until our last follow-up. The rates of hematologic and infectious toxicities were 36.8% and 47.4% after ruxolitinib treatment. Ruxolitinib is an effective salvage treatment for MDR-GVHD in haplo-HSCT recipients.

Unmanipulated haplo-identical donor transplantation compared with identical sibling donor had better anti-leukemia effect for refractory/relapsed acute myeloid leukemia not in remission status.

Prior studies have suggested that for leukemia patients with high-risk features, haplo-identical-hematopoietic stem cell transplantation (HID-HSCT) has a stronger anti-leukemia effect compared with HSCT using an identical sibling donor (ISD-HSCT). However, it is unclear whether an HID-HSC transplant also augments the graft-versus-leukemia (GVL) effect among refractory/relapsed (R/R) acute myeloid leukemia (AML) patients who are not in remission (NR). We conducted a retrospective analysis of 124 R/R AML patients with NR status who underwent HID-HSCT between April 2012 and December 2016 and compared these to 27 R/R AML patients who underwent an ISD-HSCT within the same timeframe. Among all of the patients, 68 (45.0%) had primary induction failure (PIF) and 83 (54.9%) were relapsed and had failed to respond to at least one cycle of salvage combination chemotherapy. Myeloablative conditioning regimens were administered to all patients. Here, we present a retrospective multivariate analysis of pre-transplantation risk factors and characteristics of all 151 patients and developed a predictive scoring system to predict patient survival. The median period of follow-up was 46 months for all patients. The HID cohort had a higher 5-year overall survival (OS) compared with the ISD cohort (48.6% ± 4.6% vs 25.9% ± 8.4, respectively; P = 0.017) and higher LFS (leukemia-free survival) (41.6% ± 7.5% vs 25.9% ± 8.4%, respectively; P = 0.019). There was no difference in the 5-year cumulative incidence of non-relapse mortality (NRM) (18.0% ± 3.8% and 34.9% ± 12.6%, respectively; P = 0.212) between the two group. However, the 5-year cumulative incidence of relapse (CIRs) was lower in the HID group compared with the ISD group (55.4% ± 8.9% vs 67.3% ± 9.9%, respectively; P = 0.021). Multivariate analysis showed three risk factors associated with OS and LFS: (1) ISD-HSCT, (2) use of a standardized conditioning regimen, and (3) less than 50% proportional reduction of blast cells in the bone marrow (BM). Based on these three risk factors, we developed a predictive scoring system for R/R AML patients undergoing HSCT. Patients who had a predictive score of 0 and 1 had a 66.6% ± 4.5% and 44.1% ± 3.6% OS rate at 5 years, respectively. Patients with a score ≥ 2 had only a 4.4 ± 0.2% OS rate at 5 years. An HID-HSCT had a better anti-leukemia effect among R/R AML patients with an NR status compared with an ISD-HSCT. We also identified pre-transplantation risk factors to delineate subgroups that could derive maximal benefit from HSCT.

Evolution of the role of haploidentical stem cell transplantation: past, present, and future.

INTRODUCTION: The accessibility to haplo-donors has led to an increase in the number of haplo-HSCT worldwide. A systematic search of the PubMed database between 2000 to present was performed. AREAS COVERED: In this review, the authors discussed the most used approaches to perform haplo-HSCT and its results: T-cell depletion (TCD, including Perugia platform and its modifications) and T-cell repleted haplo (TCR, including the high-dose post-transplant cyclophosphamide strategy (Baltimore protocol) and the Beijing protocol). The improvements and modifications made to the different strategies have increased the indications of haplo-HSCT, including both malignant and nonmalignant disorders. Focusing on the Baltimore protocol, the authors review the results of the retrospective studies that have compared it to other donor transplants. The limitations of this strategy in terms of toxicity, graft complications, and GVHD are also discussed in detail. Finally, possible approaches to improve the outcomes of TCR haplo-HSCT are presented. EXPERT OPINION: The recent advances in the field of haplo-HSCT have allowed a large number of patients with incurable diseases to benefit from this procedure despite not having a matched donor. With all available strategies, virtually no patient who needs an allogeneic transplant should be excluded by the absence of a donor.

Rescue haploidentical peripheral blood stem cell transplantation for engraftment failure: a single-centre case series.

Graft failure affects approximately 5% of allogeneic stem cell transplants, with a poor prognosis. Salvage second allogeneic stem cell transplantation (alloSCT2) is limited by high rates of transplant-related mortality from infection and graft-versus-host disease. We report on five adult patients receiving rescue alloSCT2 using haploidentical peripheral blood stem cells. All patients achieved neutrophil engraftment, two subsequently died from sepsis and disease relapse, respectively. Three patients remain alive up to 2 years post-transplant. We suggest consideration of haploidentical alloSCT2 for patients with graft failure.

Is the use of unrelated donor transplantation leveling off in Europe? The 2016 European Society for Blood and Marrow Transplant activity survey report.

Hematopoietic cell transplantation (HCT) is an established procedure for acquired and congenital disorders of the hematopoietic system. In 2016, there was a tendency for continued activity in this field with 43,636 HCT in 39,313 patients [16,507 allogeneic (42%), 22,806 autologous (58%)] reported by 679 centers in 49 countries in 2016. The main indications were myeloid malignancies 9547 (24%; 96% allogeneic), lymphoid malignancies 25,618 (65%; 20% allogeneic), solid tumors 1516 (4%; 2% allogeneic), and non-malignant disorders 2459 (6%; 85% allogeneic). There was a remarkable leveling off in the use of unrelated donor HCT being replaced by haploidentical HCT. Continued growth in allogeneic HCT for marrow failure, AML, and MPN was seen, whereas MDS appears stable. Allogeneic HCT for lymphoid malignancies vary in trend with increases for NHL and decreases for Hodgkin lymphoma and myeloma. Trends in CLL are not clear, with recent increases after a decrease in activity. In autologous HCT, the use in myeloma continues to expand but is stable in Hodgkin lymphoma. There is a notable increase in autologous HCT for autoimmune disease. These data reflect the most recent advances in the field, in which some trends and changes are likely to be related to development of non-transplant technologies.

T-cell-depleted haploidentical stem cell transplantation results improve with time in adults with acute leukemia: A study from the Acute Leukemia Working Party of the European Society of Blood and Marrow Transplantation (EBMT).

BACKGROUND: T-cell-depleted, haploidentical transplantations (haplos) are commonly offered to patients who have high-risk, acute leukemia in the absence of a human leukocyte antigen (HLA) full-matched donor. METHODS: To determine the effect of transplantation period, the authors divided 308 adults with de novo, acute leukemia who underwent T-cell-depleted haplo from 2005 to 2015 into 2 groups, according the year in which they underwent transplantation (2005-2011 [n = 191] and 2012-2015 [n = 117]). RESULTS: The median age was 41 years in patients who underwent transplantation before 2012 and 46 years in those who underwent transplantation after 2012 (P = .04). Most patients had acute myeloid leukemia (75% vs 69%; P = .26) and were in first complete remission (CR1) (55% vs 64%; P = .12) at the time of transplantation. The cumulative incidence of grade 2, 3, and 4 acute graft-versus-host disease (GvHD) and chronic GvHD were not different between the 2 groups (acute GvHD: 20% vs 22% cumulative incidence in patients who underwent haplo before and after 2012, respectively [P = .67]; chronic GvHD: 19% vs 11% cumulative incidence, respectively; P = .12]. The 2-year relapse incidence was 20%, the nonrelapse mortality (NRM) rate was 48%, and no difference was observed over time (21% vs 19% [P = .72] and 54% vs 38% [P = .11] for patients who underwent haplo before and after 2012, respectively). The main cause of NRM was infection. Haplo after 2012 (hazard ratio [HR], 0.57; P = .01), younger age (HR, 0.82; P = .02), and receipt of a reduced-intensity conditioning (RIC) regimen (HR, 0.53; P = .01) were independently associated with lower NRM. The 2-year overall survival rate was 36% and improved after 2012 (29% vs 47% before 2012; P = .02); and it was higher for patients who underwent transplantation in CR1 (41% vs 29%; P = .01). In multivariate analysis, haplo after 2012 (HR, 0.54; P = .003) and receipt of a RIC regimen (HR, 0.54; P = .005) were independently associated with better overall survival. Similarly, leukemia-free survival and GvHD-free/relapse-free survival (GRFS) improved over time: the leukemia-free survival rate was 31% (25% vs 43% in the groups who underwent transplantation before and after 2012, respectively; P = .05), and the GRFS rate was 24% (19% vs 34%, respectively; P = .09). In addition, leukemia-free survival and GRFS improved among patients who received a RIC regimen. CONCLUSIONS: The outcome of patients with acute leukemia who underwent T-cell-depleted haplo has improved over time. Cancer 2018;124:2142-50. © 2018 American Cancer Society.

Proceedings From the Fourth Haploidentical Stem Cell Transplantation Symposium (HAPLO2016), San Diego, California, December 1, 2016.

The resurgence of haploidentical stem cell transplantation (HaploSCT) over the last decade is one of the most important advances in the field of hematopoietic stem cell transplantation (HSCT). The modified platforms of T cell depletion either ex vivo (CD34+ cell selection, "megadoses" of purified CD34+ cells, or selective depletion of T cells) or newer platforms of in vivo depletion of T cells, with either post-transplantation high-dose cyclophosphamide or intensified immune suppression, have contributed to better outcomes, with survival similar to that in HLA-matched donor transplantation. Further efforts are underway to control viral reactivation using modified T cells, improve immunologic reconstitution, and decrease the relapse rate post-transplantation using donor-derived cellular therapy products, such as genetically modified donor lymphocytes and natural killer cells. Improvements in treatment-related mortality have allowed the extension of haploidentical donor transplants to patients with hemoglobinopathies, such as thalassemia and sickle cell disease, and the possible development of platforms for immunotherapy in solid tumors. Moreover, combining HSCT from a related donor with solid organ transplantation could allow early tapering of immunosuppression in recipients of solid organ transplants and hopefully prevent organ rejection in this setting. This symposium summarizes some of the most important recent advances in HaploSCT and provides a glimpse in the future of fast growing field.

Advances in haploidentical stem cell transplantation for hematologic malignancies.

One of the most important advances in allogeneic hematopoietic stem cell transplantation (allo-HSCT) is the use of alternative donors and cell sources, such as haploidentical transplants (haplo-HSCT) from family donors. Several approaches have been developed to overcome the challenging bidirectional alloreactivity. We discuss these approaches, including ex vivo T-cell-depleted grafts with megadose of CD34(+) cells, not requiring immunosuppression after allogeneic transplantation for graft-versus-host disease (GVHD) prophylaxis, and other strategies using unmanipulated T-cell-replete grafts with intensive immunosuppression or post-transplantation cyclophosphamide to minimize the GVHD. We also address the role of other strategies developed in the context of the haplo-HSCT platforms, such as ex vivo selective depletion of alloreactive donor T-cell subpopulations, infusion of antigen-specific T-cells against several pathogens, and infusion of regulatory T-cells, among other experimental approaches. Finally, some considerations about the selection of the most suitable donor, when more than one family member is available, are also addressed.