Unmanipulated haploidentical transplants compared with other alternative donors and matched sibling grafts

Haploidentical Hematopoietic Cell Transplant with Post-Transplant Cyclophosphamide and Peripheral Blood Stem Cell Grafts in Older Adults with Acute Myeloid Leukemia or Myelodysplastic Syndrome

Many hematologic malignancies are diseases of aging, and the use of hematopoietic cell transplant (HCT) is growing rapidly among older adults. Modern post-transplant cyclophosphamide (PTCy) protocols with haploidentical (haplo) donors have dramatically expanded the donor pool for patients requiring HCT. Initial studies were performed with bone marrow grafts, which require the donor to undergo anesthesia during harvest. However, the use of mobilized peripheral blood stem cells (PBSCs) may be desirable, especially with older donors. However, data on PBSC haplo-HCT in older adults are lacking. To characterize the impact of age on outcomes in haplo-HCT, we identified all adult patients undergoing haplo-HCT with PTCy for acute myeloid leukemia (AML) or myelodysplastic syndrome (MDS) at our institution from January 2009 to June 2016. Patients were grouped into 3 cohorts: Age 1 (≤55), Age 2 (55 to 65), and Age 3 (≥65). To characterize the impact of donor type on outcomes in older patients, we identified age- and disease risk index (DRI)-matched patient age ≥ 65 undergoing HLA-matched unrelated donor (MUD) HCT for AML or MDS during the same time frame. Patients were scored for disease risk and underlying comorbidities using the DRI and HCT-specific comorbidity index. Overall survival (OS) was analyzed using 3 different Cox proportional hazards models. We identified 112 haplo-HCT patients, 95 with AML and 17 with MDS. There were 61 patients in Age 1, 29 patients in Age 2, and 22 in Age 3. Median OS was 448, 397, and 147 days in Age 1, Age 2, and Age 3 patients (log-rank, P = .04). After adjusting for other risk factors, age ≥ 65 was associated with significantly worse OS after haplo-HCT (aHR, 2.16; 95% CI, 1.15 to 4.07). There was a trend toward increased relapse among older patients at 2 years (56%; 95% CI, 32% to 79%) versus Age 1 (41%; 95% CI, 28% to 54%) and Age 2 (31%; 95% CI, 12% to 50%) (P = .08). Among patients age ≥ 65, donor type (MUD versus haplo) did not impact OS (aHR, 1.03; 95% CI, .56 to 1.88) after adjusting for other risk factors. Prior allo-HCT (aHR, 4.95; 95% CI, 1.82 to 13.49) and myeloablative conditioning (aHR, 1.97; 95% CI, 1.04 to 3.73) were associated with inferior survival. Although age ≥ 65 was associated with inferior OS in our haplo-HCT cohort, no difference was seen in survival between MUD and haplo-HCT. Therefore, the use of haploidentical donors in older patients is a reasonable treatment option, especially if there is concern for clinical deterioration. A careful pretransplant evaluation and analysis of risks and benefits is warranted when offering this transplant modality to older adults, especially in patients with previous transplant or poor performance status. Strategies to reduce the risk of relapse and decrease nonrelapse mortality in older adults are areas of ongoing research, and prospective studies are needed.

Similar outcomes after haploidentical transplantation with post-transplant cyclophosphamide versus HLA-matched transplantation: a meta-analysis of case-control studies

Background

Outcomes of haploidentical hematopoietic cell transplantation (haplo-HCT) with post-transplant cyclophosphamide (PT-Cy) have greatly improved. It remains unknown whether haplo-HCT with PT-Cy was associated with poor outcomes when compared with HLA-matched HCT. To address this issue, we performed a meta-analysis to compare outcomes of haplo-HCT with PT-Cy with those of HLA-matched HCT.

Methods

A systematic search for case-control studies were performed in PubMed, Embase and Cochrane Library databases. Using a random model, the risk ratios (RRs) and 95% confidence intervals (95% CI) were pooled for the final analysis.

Results

Nine case-control studies including 2258 patients (827 patients in the haplo-HCT with PT-Cy group, 748 controls from HLA-matched related donors (MRD), and 683 controls from HLA-matched unrelated donors (MUD)) met the inclusion criteria. No differences were found between haplo-HCT with PT-Cy and HLA-matched HCT with regard to acute graft-versus-host-disease (GVHD), non-relapse mortality, relapse, progression free survival and overall survival. However, haplo-HCT with PT-Cy was found to be associated with a lower incidence of moderate to severe chronic GVHD (Haplo vs MRD: RR=0.54; 95% CI=0.39-0.75; Haplo vs MUD: RR=0.70; 95% CI=0.56-0.88).

Conclusions

The results of this meta-analysis suggest that haplo-HCT with PT-Cy can achieve comparable outcomes with those of HLA-matched HCT. Haploidentical donors can be a feasible and valid alternative when conventional HLA-matched donors are unavailable.

Mobilized Peripheral Blood Stem Cells Versus Unstimulated Bone Marrow As a Graft Source for T-Cell-Replete Haploidentical Donor Transplantation Using Post-Transplant Cyclophosphamide

Purpose T-cell-replete HLA-haploidentical donor hematopoietic transplantation using post-transplant cyclophosphamide was originally described using bone marrow (BM). With increasing use of mobilized peripheral blood (PB), we compared transplant outcomes after PB and BM transplants. Patients and Methods A total of 681 patients with hematologic malignancy who underwent transplantation in the United States between 2009 and 2014 received BM (n = 481) or PB (n = 190) grafts. Cox regression models were built to examine differences in transplant outcomes by graft type, adjusting for patient, disease, and transplant characteristics. Results Hematopoietic recovery was similar after transplantation of BM and PB (28-day neutrophil recovery, 88% v 93%, P = .07; 100-day platelet recovery, 88% v 85%, P = .33). Risks of grade 2 to 4 acute (hazard ratio [HR], 0.45; P < .001) and chronic (HR, 0.35; P < .001) graft-versus-host disease were lower with transplantation of BM compared with PB. There were no significant differences in overall survival by graft type (HR, 0.99; P = .98), with rates of 54% and 57% at 2 years after transplantation of BM and PB, respectively. There were no differences in nonrelapse mortality risks (HR, 0.92; P = .74) but relapse risks were higher after transplantation of BM (HR, 1.49; P = .009). Additional exploration confirmed that the higher relapse risks after transplantation of BM were limited to patients with leukemia (HR, 1.73; P = .002) and not lymphoma (HR, 0.87; P = .64). Conclusion PB and BM grafts are suitable for haploidentical transplantation with the post-transplant cyclophosphamide approach but with differing patterns of treatment failure. Although, to our knowledge, this is the most comprehensive comparison, these findings must be validated in a randomized prospective comparison with adequate follow-up.

Donor and recipient age, gender and ABO incompatibility regardless of donor source: validated criteria for donor selection for haematopoietic transplants

Prior data indicate similar outcomes after transplants from human leukocyte antigen (HLA)-haplotype-matched relatives, HLA-identical siblings and HLA-matched unrelated donors. We used our prospective data set to answer a clinically important question: who is the best donor for a person with acute leukaemia transplanted in first complete remission. Patients were randomly divided into training (n=611) and validation (n=588) sets. A total of 1199 consecutive subjects received a transplant from an HLA-haplotype-matched relative using granulocyte colony-stimulating factor and anti-thymocyte globulin (n=685) or an HLA-identical sibling (n=514); 3-year leukaemia-free survivals (LFSs) were 75 and 74% (P=0.95), respectively. The multivariate model identified three major risk factors for transplant-related mortality (TRM): older donor/recipient age, female-to-male transplants and donor-recipient ABO major-mismatch transplants. A risk score was developed based on these three features. TRMs were 8%, 15% and 31% for subjects with scores of 0-1, 2 and 3, respectively, (P<0.001). Three-year LFSs were 78%, 74% and 58%, respectively, (P=0.003). The risk score was validated in an independent cohort. In conclusion, our data confirm donor source is not significantly correlated with transplant outcomes. Selection of the best donor needs to consider donor-recipient age, matching for gender and ABO incompatibility among persons with acute leukaemia receiving related transplants under our transplant modality.

Single-agent GvHD prophylaxis with tacrolimus after post-transplant high-dose cyclophosphamide is a valid option for haploidentical transplantation in adults with hematological malignancies

Eighty-one patients with high-risk hematological malignancies received unmanipulated haploidentical stem cell transplants (haploSCT) using the same protocol at four Spanish institutions. The conditioning regimen was thiotepa, busulfan and fludarabine; following bone marrow or peripheral blood infusion. GvHD prophylaxis with high-dose cyclophosphamide on days +3 and +4, and IV tacrolimus from day +5 was administered. 62% were in complete remission, 17% had received previous allogeneic SCT and 44% had a high-very high refined disease risk index. One patient had primary graft failure and three more died before +21. The median days to neutrophil and platelet recoveries were +18 and +23, respectively, and 93% achieved a full donor chimerism on day +30. At 1 year, cumulative incidences (CumInc) of non-relapse mortality and relapse were 27 and 19%. One-year overall survival and PFS were 61 and 51%. CumInc of grade II-IV and III-IV were 23 and 14%. At 30 months, CumInc of limited and extensive GvHD were 20 and 22%. In conclusion, patients with hematological malignancies who receive an unmanipulated haploSCT with post-transplant cyclophosphamide may benefit from less intense pharmacological prophylaxis for GvHD prophylaxis. Whether this approach potentiates the graft-versus-tumor effect and decreases relapses requires further investigation.

Engineering cord blood to improve engraftment after cord blood transplant

Umbilical cord blood transplant (CBT) has traditionally been associated with slower engraftment of neutrophils, delayed immune reconstitution and consequently higher risk of infections as compared with peripheral blood progenitor cell (PBPC) or bone marrow (BM) transplants. This is primarily due to low numbers of total nucleated cells (TNCs) and the naive nature of CB immune cells. The use of double unit CB transplant (DCBT) increases the total cell dose in the graft, but it still does not produce as rapid engraftment as seen with PBPC or even BM transplants. Herein, we discuss strategies to improve engraftment after CBT. We describe methods of (I) expansion of CB graft ex vivo to increase the total cell dose; and (II) enhancement of BM homing capability of CB progenitor cells; (III) ex vivo expansion of CB derived T cells for improving T cell function against viruses, tumors and protection from graft versus host disease (GVHD). With these novel approaches, engraftment after CBT is now reaching levels comparable to that of other graft types.

Alternative Donor Graft Sources for Adults with Hematologic Malignancies: A Donor for All Patients in 2017!

Hematopoietic stem cell transplant (HSCT) is potentially curative for a wide variety of malignant diseases, including acute and leukemias, lymphoma, and myelodysplasia. Choice of a stem cell donor is dependent on donor availability, donor compatibility and health, recipient disease type, and recipient condition. Current sources of stem cell donation for HSCT are matched sibling donors (MSDs), matched unrelated donors (MUDs), 1-antigen mismatched unrelated donors (MMUDs), haploidentical donors (haplo), and umbilical cord blood (UCB) units. Historically, preferred donors for HSCT have been human leukocyte antigen (HLA)-matched sibling donors; however, only about 30% of U.S. patients will have a MSD available. The majority of patients referred for HSCT will require an alternative donor graft: MUD, MMUD, UCB, or haplo. The likelihood of finding a MUD varies depending on the ethnicity of the recipient. White Caucasians of European descent have the greatest chance of finding a MUD. Chances of finding a MUD are significantly less for African-American or Hispanic recipients due to HLA polymorphisms. Therefore, MMUD, UCB, and haplo donor graft sources expand the donor pool for recipients who do not have a MSD or MUD available. Given the variety of different donor stem cell sources available today, nearly every patient who needs an allogeneic HSCT has a potential donor in 2017. All transplant-eligible patients with hematologic malignancies should be evaluated by a transplant center to determine if HSCT is a viable treatment option for their underlying disease process.

IMPLICATIONS FOR PRACTICE

The goal of this review is to increase the awareness of oncology practitioners to the availability of alternative donor stem cell transplants for patients with hematologic malignancies. Despite new agents, stem cell transplant remains the only curative therapy for many patients with acute and chronic leukemia, myelodysplasia, and lymphoma. Given the variety of different donor stem cell sources available today, nearly every patient who needs an allogeneic stem cell transplant will have a donor.

A review of infectious complications after haploidentical hematopoietic stem cell transplantations

BACKGROUND

Allogeneic hematopoietic stem cell transplantation from haploidentical donor is a feasible option for patients with hematological diseases who lack a suitable HLA-matched donor, but viral and fungal infections are still the most common causes of morbidity and mortality in haploidentical transplantation setting because of delayed immune reconstitution, increased risk of graft vs host disease (GvHD) or systemic steroid use. Therefore, this review will focus on the infectious complications after haploidentical hematopoietic stem cell transplantation (HSCT).

MATERIALS AND METHODS

Electronic publications were searched until February 2017 throughout databases, including Pubmed, Cochrane, and Embase. The following keywords were used 'haploidentical transplantation', 'infection', 'T cell replete', and 'T cell deplete'.

RESULTS

An increased incidence of bacterial, fungal, or viral infections is detected in haplo-HSCT compared to related, unrelated, or cord blood transplantations. Neutropenia and use of systemic steroid for GvHD and delayed immune reconstitution are important risk factors for infection after haplo-HSCT.

CONCLUSION

A shift towards T cell repletes haplo-HSCT with post-transplant cyclophosphamide (CY) for GvHD has been emerged in recent years, in which the incidence of viral and fungal infections is detected to be lower. Prophylaxis and pre-emptive treatment strategies should be applied according to patient status.

Fever after peripheral blood stem cell infusion in haploidentical transplantation with post-transplant cyclophosphamide

OBJECTIVE/BACKGROUND

Noninfection-related fever can occur after peripheral blood stem cell infusion in haploidentical hematopoietic stem cell transplantation with post-transplant cyclophosphamide. The objective of this study was to analyze the incidence of fever and characterize some clinical features of affected patients.

METHODS

A retrospective case-series study with 40 patients who received haploidentical hematopoietic stem cell transplantation was carried out.

RESULTS

Thirty-three patients (82.5%) developed fever; no baseline characteristic was associated with its development. Median time to fever onset was 25.5h (range, 9.5-100h) and median peak temperature was 39.0°C (range, 38.1-40.5°C). Not a single patient developed hemodynamic or respiratory compromise that required admission to the intensive care unit. Fever was not explained by infection in any case. Ninety-one percent of the febrile episodes resolved within 96h of cyclophosphamide administration. No significant difference in overall survival, event-free survival, or graft versus host disease-free/relapse-free survival was found in the group of febrile individuals after peripheral blood stem cell infusion.

CONCLUSION

Fever after peripheral blood stem cell infusion in this clinical setting was common; it usually subsides with cyclophosphamide administration. The development of fever was not associated with an adverse prognosis.

Outcomes of haploidentical transplant compared with matched donor allogeneic stem cell transplant

The risk of acute and chronic graft-versus-host disease (GVHD) with haploidentical transplant with post-transplant high-dose cyclophosphamide may be lower compared with matched unrelated donor transplant and largely similar to matched related donor transplant. The lower probability of GVHD with the haploidentical donor may result in a risk of nonrelapse mortality that is at least similar to or even lower than the matched donor. The incidence of relapse and survival are also largely similar to different donor types. Haploidentical transplant may be associated with slower engraftment. Given a lower risk of GVHD, haploidentical transplant has gained popularity. Additionally, the use of post-transplant high-dose cyclophosphamide has been extended to lower the risk of GVHD with matched donor and mismatched unrelated donor transplant.

Alternative donors for allogeneic hematopoietic stem cell transplantation in poor-risk AML in CR1

Allogeneic hematopoietic stem cell transplantation (alloHSCT) remains the treatment of choice to consolidate remission in patients with poor-risk acute myeloid leukemia (AML). With increasing alternative donors available, the preferred donor or stem cell source is debated. We set out to study outcome in recipients of alloHSCT with poor-risk AML in first complete remission (CR1) by donor type. A total of 6545 adult patients with poor-risk AML in CR1 receiving an alloHSCT using matched related donor (MRD, n = 3511) or alternative donors, including 10/10 (n = 1959) or 9/10 matched unrelated donors (MUDs, n = 549), umbilical cord blood (UCB) grafts (n = 333), or haplo-identical (haplo) donors (n = 193) were compared. Overall survival (OS) at 2 years following MRD alloHSCT was an estimated 59 ± 1%, which did not differ from 10/10 MUD (57 ± 1%) and haplo alloHSCT (57 ± 4%). OS, however, was significantly lower for 9/10 MUD alloHSCT (49 ± 2%) and UCB grafts (44 ± 3%), respectively (P < .001). Nonrelapse mortality (NRM) depended on donor type and was estimated at 26 ± 3% and 29 ± 3% after haplo alloHSCT and UCB grafts at 2 years vs 15 ± 1% following MRD alloHSCT. Multivariable analysis confirmed the impact of donor type with OS following MRD, 10/10 MUD, and haplo alloHSCT not being statistically significantly different. NRM was significantly higher for alternative donors as compared with MRD alloHSCT. Collectively, these results suggest that alloHSCT with MRDs and 10/10 MUDs may still be preferred in patients with poor-risk AML in CR1. If an MRD or 10/10 MUD is not available, then the repertoire of alternative donors includes 9/10 MUD, UCB grafts, and haplo-identical donors. The latter type of donor is increasingly applied and now approximates results with matched donors.

Related haploidentical donors are a better choice than matched unrelated donors: Counterpoint

Publisher's Note: This article has a companion Point by Fuchs. Publisher's Note: Join in the discussion of these articles at Blood Advances Community Conversations.

Related haploidentical donors are a better choice than matched unrelated donors: Point

Publisher's Note: This article has a companion Counterpoint by Shaw. Publisher's Note: Join in the discussion of these articles at Blood Advances Community Conversations.

Epidemiology of infections following haploidentical peripheral blood hematopoietic cell transplantation

BACKGROUND

The use of T-cell replete haploidentical hematopoietic cell transplant (haplo-HCT) has increased substantially since the introduction of post-transplant cyclophosphamide (PTCy) regimens. Limited data exist concerning infectious complications of haplo-HCT utilizing mobilized peripheral blood (PB) hematopoietic cells.

METHODS

This retrospective cohort study included all adult patients at our institution undergoing PB haplo-HCT with PTCy between June 2009 and June 2015. Infections were microbiologically confirmed. Invasive fungal infections (IFI) classified as "proven" or "probable" by standard definitions were included.

RESULTS

In total, 104 patients were identified. Median follow-up was 218 days (range: 6-1576). A total of 322 episodes of infection were recorded. Eighty-nine percent of patients experienced at least one infection. Median time to first infection was 22 days. Patients experiencing at least one bacterial, viral, and IFI were 62%, 72%, and 6%, respectively. The majority (69%) of bacterial infections were caused by enteric organisms. Seven cases of Staphylococcus aureus infection were recorded, with one bacteremia case. Cytomegalovirus (CMV) viremia occurred in 54/71 (76%) at-risk patients at a median time of 24 days. Sixteen (15%) patients developed CMV disease. Nineteen percent (20/104) of patients developed BK polyomavirus-associated cystitis. Six (6%) patients experienced a total of seven IFI. Infection was the primary cause of death for 12% (6/51) of patients and was a secondary cause for 41%.

CONCLUSION

In PB haplo-HCT patients, a high incidence of CMV viremia and disease was observed. Infections with enteric bacteria were common. Fungal and staphylococcal infections were uncommon. Further studies are needed to compare infectious complications in haplo-HCT with other transplant modalities.

Intesive fludarabine-high dose cytarabine-idarubicin combination as induction therapy with risk-adapted consolidation may improve treatment efficacy in younger Acute Myeloid Leukemia (AML) patients: Rationales, evidences and future perspectives

Acute Myeloid Leukemia (AML) is the commonest form of leukemia in the adults, with an incidence of 3-4 cases per 100,000 people/year. After the first description of the effective cytarabine + antracycline (3+7) induction regimen, in the last 3 decades, no effective targeted drug has been included in the standard treatment of AML. Many efforts of modifying 3+7 adding a third drug or increasing the dose of anthracycline, cytarabine or both did not lead to substantial improvements, mainly due to increased toxicity. Many in vitro and in vivo evidences suggested that fludarabine may increase efficacy of cytarabine through a synergistic effect. Considering the continuous improvements in supportive care and management of infectious complications the feasibility of more intensive induction strategies have increased and a renewed interest in fludarabine-containing induction strategies arose. The recent MRC AML 15 trial has shown that a fludarabine-containing induction, FLAG-Ida, resulted superior to conventional 3+7 in terms of complete remission rates, relapse incidence and survival, although only a minority of patients could complete the whole planned consolidation program due to an excessive hematological toxicity. Our group recently published a 10-year experience with a fludarabine-containing induction that slightly differed from the MRC one and resulted in good efficacy and higher feasibility. In this commentary we review the major evidences supporting the employ of a fludarabine-containing induction in AML, and discuss the future perspectives.

A comparison between allogeneic stem cell transplantation from unmanipulated haploidentical and unrelated donors in acute leukemia

BACKGROUND

In the absence of a HLA-matched related or matched unrelated donor, allogeneic stem cell transplantation (allo-SCT) from mismatched unrelated donors or haploidentical donors are potential alternatives for patients with acute leukemia with an indication to allo-SCT. The objective of this study was to compare the outcome of allo-SCT from T cell-replete haploidentical (Haplo) versus matched (MUD 10/10) or mismatched unrelated donor at a single HLA-locus (MMUD 9/10) for patients with acute leukemia in remission.

METHODS

Two hundred sixty-five adult patients with de novo acute leukemia in first or second remission that received a Haplo-SCT between January 2007 and December 2013 were compared with 2490 patients receiving a MUD 10/10 and 813 receiving a MMUD 9/10. Propensity score weighted analysis was conducted in order to control for disease risk imbalances between the groups.

RESULTS

The weighted 3-year non-relapse mortality and relapse incidence were 29 and 30% for Haplo, 21 and 29% for MUD 10/10, and 29 and 25% for MMUD 9/10, respectively. The weighted 3-year leukemia-free survival (LFS) and overall survival (OS) were 41 and 46% for Haplo, 50 and 56% for MUD 10/10, and 46 and 48% for MMUD 9/10, respectively. Using weighted Cox model, both LFS and OS were significantly higher in transplants from MUD 10/10 compared from those in Haplo but not different between transplants from MMUD 9/10 and Haplo. The type of donor was not significantly associated with neither acute nor chronic graft-versus-host disease.

CONCLUSIONS

Patients with acute leukemia in remission have better outcomes if transplanted from a MUD 10/10. We did not find any significant difference in outcome between transplants from MMUD 9/10 and Haplo, suggesting that both can be equally used in the absence of a 10/10 MUD. KEY POINT 1: Better outcomes using fully (10/10) matched unrelated donor for allo-SCT in acute leukemia in remission. KEY POINT 2: Similar outcomes after allo-SCT from unmanipulated haploidentical graft or mismatched (9/10) unrelated donor in acute leukemia in remission.

Haploidentical transplantation of hematopoietic stem cells

OBJECTIVE

To review and discuss the literature on hematopoietic stem cell transplantation (HSCT) with haploidentical donors in Brazil.

METHOD

Literature review.

RESULTS

The haploidentical hematopoietic stem cell transplantations have become a safe option in hematology since the 80s, with the possibility of ex-vivo T-cell depletion. However, its broad use worldwide occurred with the advent of haploidentical nonmyeloablative transplants using in vivo T-cell depletion with the administration of post-transplant cyclophosphamide. The results were encouraging, despite the increased risk of infection and post-transplantation recurrence. Recent publications on acute myeloid leukemia, myelodysplastic syndrome and Hodgkin's lymphoma have shown similar results among haploidentical, unrelated and related full-match transplants. Obviously, these findings of retrospective studies should be confirmed by clinical trials.

CONCLUSIONS

Transplantation with haploidentical donor has shown to be feasible in Brazil and the first publications and results are showing encouraging results.

Comparable post-relapse outcomes between haploidentical and matched related donor allogeneic stem cell transplantation

We investigated the impact of donor type on post-relapse survival (PRS) in 85 patients with hematological relapse after their first allogeneic hematological stem cell transplantation (allo-HSCT) for hematological malignancy. The median follow-up was 64 months among survivors. Both 3-year overall survival and 3-year PRS were similar in haploidentical donor (HID) and matched sibling donor (MRD) transplantation (13.0%±4.7% vs 19.4%±7.1%, P=0.913 and 7.7±3.9% vs 9.7±5.3%, P= 0.667). Higher rates of post-relapse grade II-IV and III-IV acute GvHD (aGvHD) were observed in HID transplantation patients. A higher cumulative incidence of post-relapse extensive chronic GvHD was also observed for HID transplantation patients. Multivariate analyses confirmed that treatment including donor lymphocyte infusion (DLI), late relapse >1 year, and in first CR at transplantation were associated with superior PRS (P=0.012, hazard ratio (HR)=0.527 (0.320-0.866)); P=0.033, HR=0.534 (0.300-0.952) and P=0.046, HR=0.630 (0.400-0.992). The data suggest that post-relapse outcomes are comparable in HID and MRD transplantation, and that DLI is safe for relapsed patients after haploidentical transplantation.

Immunity to Infections after Haploidentical Hematopoietic Stem Cell Transplantation

The advantage of using a Human Leukocyte Antigen (HLA)-mismatched related donor is that almost every patient who does not have an HLA-identical donor or who urgently needs hematopoietic stem cell transplantation (HSCT) has at least one family member with whom shares one haplotype (haploidentical) and who is promptly available as a donor. The major challenge of haplo-HSCT is intense bi-directional alloreactivity leading to high incidences of graft rejection and graft-versus-host disease (GVHD). Advances in graft processing and pharmacologic prophylaxis of GVHD have reduced these risks and have made haplo-HSCT a viable alternative for patients lacking a matched donor. Indeed, the haplo-HSCT has spread to centers worldwide even though some centers have preferred an approach based on T cell depletion of G-CSF-mobilized peripheral blood progenitor cells (PBPCs), others have focused on new strategies for GvHD prevention, such as G-CSF priming of bone marrow and robust post-transplant immune suppression or post-transplant cyclophosphamide (PTCY). Today, the graft can be a megadose of T-cell depleted PBPCs or a standard dose of unmanipulated bone marrow and/or PBPCs. Although haplo-HSCT modalities are based mainly on high intensity conditioning regimens, recently introduced reduced intensity regimens (RIC) showed promise in decreasing early transplant-related mortality (TRM), and extending the opportunity of HSCT to an elderly population with more comorbidities. Infections are still mostly responsible for toxicity and non-relapse mortality due to prolonged immunosuppression related, or not, to GVHD. Future challenges lie in determining the safest preparative conditioning regimen, minimizing GvHD and promoting rapid and more robust immune reconstitution.

Comparable composite endpoints after HLA-matched and HLA-haploidentical transplantation with post-transplantation cyclophosphamide

Composite endpoints that not only encompass mortality and relapse, but other critical post-transplant events such as graft-versus-host disease, are being increasingly utilized to quantify survival without significant morbidity after allogeneic blood or marrow transplantation. High-dose, post-transplantation cyclophosphamide reduces severe graft-versus-host disease with allogeneic marrow transplantation, making composite endpoints after this management particularly interesting. We retrospectively analyzed 684 adults with hematologic malignancies who received T-cell-replete bone marrow grafts and cyclophosphamide after myeloablative HLA-matched related (n=192) or unrelated (n=120), or non-myeloablative HLA-haploidentical (n=372) donor transplantation. The median follow up was 4 (range, 0.02-11.4) years. Graft-versus-host disease-free, relapse-free survival was defined as the time after transplantation without grade III-IV acute graft-versus-host disease, chronic graft-versus-host disease requiring systemic treatment, relapse, or death. Chronic graft-versus-host disease-free, relapse-free survival was defined as the time after transplantation without moderate or severe chronic graft-versus-host disease, relapse, or death. One-year graft-versus-host disease-free, relapse-free survival and chronic graft-versus-host disease-free, relapse-free survival estimates were, respectively, 47% (95% CI: 41-55%) and 53% (95% CI: 46-61%) after myeloablative HLA-matched related, 42% (95% CI: 34-52%) and 52% (95% CI: 44-62%) after myeloablative HLA-matched unrelated, and 45% (95% CI: 40-50%) and 50% (95% CI: 45-55%) after non-myeloablative HLA-haploidentical donor transplantation. In multivariable models, there were no differences in graft-versus-host disease-free, or chronic graft-versus-host disease-free, relapse-free survival after either myeloablative HLA-matched unrelated or non-myeloablative HLA-haploidentical, compared with myeloablative HLA-matched related donor transplantation. Although limited by inclusion of dissimilar cohorts, we found that post-transplantation cyclophosphamide-based platforms yield comparable composite endpoints across conditioning intensity, donor type, and HLA match.

Haploidentical hematopoietic transplantation for the cure of leukemia: from its biology to clinical translation

The present review describes the biology of human leukocyte antigen haplotype mismatched ("haploidentical") transplantation, its translation to clinical practice to cure leukemia, and the results of current transplantation protocols. The 1990s saw what had been major drawbacks of haploidentical transplantation, ie, very strong host-versus-graft and graft-versus-host alloresponses, which led respectively to rejection and graft-versus-host disease (GVHD), being overcome through transplantation of a "mega-dose" of T cell-depleted peripheral blood hematopoietic progenitor cells and no posttransplant pharmacologic immunosuppression. The absence of posttransplant immunosuppression was an opportunity to discover natural killer cell alloreactions that eradicated acute myeloid leukemia and improved survival. Furthermore, it also unveiled the benefits of transplantation from mother donors, a likely consequence of the mother-to-child interaction during pregnancy. More recent transplantation protocols use unmanipulated (without ex vivo T-cell depletion) haploidentical grafts combined with enhanced posttransplant immunosuppression to help prevent GVHD. Unmanipulated grafts substantially extended the use of haploidentical transplantation with results than even rival those of matched hematopoietic transplantation. In T cell-depleted haploidentical transplantation, recent advances were made by the adoptive transfer of regulatory and conventional T cells.

Long-term systemic lupus erythematosus disease control after allogeneic bone marrow transplantation

Systemic lupus erythematosus (SLE), a disorder of the immune system, is potentially curable by allogeneic bone marrow transplantation (alloBMT). Until recently, alloBMT was limited by donor availability and toxicity. Reduced intensity conditioning (RIC) combined with post-transplantation cyclophosphamide (PTCy) has improved the availability and safety of alloBMT permitting its exploration in severe-refractory autoimmune illnesses. We report the six-year follow-up of a young female whose refractory SLE-associated nephrosis resolved after RIC alloBMT with PTCy.

Reappraising the timing of transplant for indolent non-Hodgkin lymphomas

INTRODUCTION

Indolent non-Hodgkin lymphomas (iNHL) remain incurable with standard approaches. The timing of autologous stem cell transplant (ASCT) is changing following the introduction of new drugs that can potentially defer the transplant, improved reduced intensity conditioning (RIC) and haploidentical allogeneic SCT (allo-SCT).

AREAS COVERED

The most relevant aspects concerning the role of hematopoietic stem cell transplantation in the management of iNHL are discussed. Literature search methodology included examination of PubMed index and meeting presentations. Expert commentary: ASCT is not currently employed as consolidation in first-line, being reserved to patients with refractory/relapsed disease. The curative potential of graft-versus-lymphoma (GVL) after RIC allo-SCT could be particularly beneficial in patients with iNHL relapsing after ASCT. This scenario could be modified in the near future by better definition of high-risk patients at diagnosis, by the improvement of minimal residual disease (MRD) evaluation and by the introduction of new drugs in the therapeutic algorithm.

The impact of HLA-matching on reduced intensity conditioning regimen unrelated donor allogeneic stem cell transplantation for acute myeloid leukemia in patients above 50 years-a report from the EBMT acute leukemia working party

Background

Data comparing fully matched and mismatched-unrelated-donor (M- and mM-URD) allogeneic hematopoietic stem cell transplant (allo-SCT) following reduced intensity conditioning regimens for acute myeloid leukemia are limited.

Methods

We retrospectively compared the outcome of 3398 patients above the age of 50 years who underwent 10/10 M-URD (n = 2567), 9/10 (n = 723), or 8/10 (n = 108) mM-URD allo-SCT for acute myeloid leukemia after reduced intensity conditioning regimen between 2000 and 2013. The Kaplan-Meier estimator, the cumulative incidence function, and Cox proportional hazards regression models were used where appropriate.

Results

HLA matching had no impact on engraftment (p = 0.31). In univariate analysis, in comparison to 10/10 M-URD, mM-URD was associated with higher incidence of grade II–IV acute graft-versus-host disease (GVHD) (p = 0.0002), similar rates of chronic GVHD (p = 0.138) but increased incidence of its extensive form (p = 0.047). Compared to 10/10 M-URD, patients transplanted in the first complete remission (CR1) with a 9 or an 8/10 mM-URD had decreased 2-year leukemia free (LFS) (p = 0.005) and overall survivals (OS) (56.7, 46.1, and 50.2 %, respectively, p = 0.005), while outcomes were comparable between all groups for patients transplanted beyond CR1. In multivariate analysis, 9/10 versus 10/10 URD was associated with higher non-relapse mortality (HR 1.34, p = 0.001), similar risk of relapse and chronic GVHD and inferior LFS (HR 1.25, p = 0.0001), and OS (HR 1.27, p = 0.0001). There was no difference in adjusted transplant outcomes between 9/10 and 8/10 mM-URD.

Conclusions

Reduced intensity conditioned allo-SCT with a 10/10 M-URD remains the preferable option for AML patients above the age of 50 years. The use of a 9/10 or an 8/10 mM-URD in patients not having a fully matched donor represents an alternative therapeutic option that should be compared to other alternative donor transplant strategies.

Electronic supplementary material

The online version of this article (doi:10.1186/s13045-016-0295-9) contains supplementary material, which is available to authorized users.

Haploidentical transplantation in children with unmanipulated peripheral blood stem cell graft: The need to look beyond post-transplantation cyclophosphamide in younger children

Haploidentical transplantation with PTCY following marrow or PBSC graft has been associated with low incidence of GVHD in adults with similar data lacking in children. We report on the outcome of 25 patients <20 yr of age (median age 12 yr), undergoing a haploidentical PBSC transplantation for both malignant and non-malignant disorders. Engraftment was prompt and sustained. Cumulative incidences of acute GVHD and chronic GVHD were 40.3% and 16.7%, respectively. On subgroup analysis, it was evident that acute GVHD developed in 80% of patients <10 yr compared to only 13.3% in those between 10 and 20 yr [log-rank p = 0.001], despite similar graft composition with significantly higher NRM (60% vs. 0%; p = 0.001). The FFS was 63.5%; (79% in >10 yr and 40% in <10 yr, p = 0.01). Our data suggest that PTCY-based haploidentical PBSC transplantation is feasible in older children, but results in early and severe alloreactivity in younger children. These findings, despite being counterintuitive, could be explained by the variable metabolism of CY and oral mycophenolate in younger children indicating that PTCY-based approach as used in adults might not be adequate for younger children.

High feasibility and antileukemic efficacy of fludarabine, cytarabine, and idarubicin (FLAI) induction followed by risk-oriented consolidation: A critical review of a 10-year, single-center experience in younger, non M3 AML patients

About 105 consecutive acute myeloid leukemia (AML) patients treated with the same induction-consolidation program between 2004 and 2013 were retrospectively analyzed. Median age was 47 years. The first induction course included fludarabine (Flu) and high-dose cytarabine (Ara-C) plus idarubicin (Ida), with or without gemtuzumab-ozogamicin (GO) 3 mg/m(2) (FLAI-5). Patients achieving complete remission (CR) received a second course without fludarabine but with higher dose of idarubicin. Patients not achieving CR received an intensified second course. Patients not scheduled for early allogeneic bone marrow transplantation (HSCT) where planned to receive at least two courses of consolidation therapy with Ara-C. Our double induction strategy significantly differs from described fludarabine-containing regimens, as patients achieving CR receive a second course without fludarabine, to avoid excess toxicity, and Ara-C consolidation is administrated at the reduced cumulative dose of 8 g/m(2) per cycle. Toxicity is a major concern in fludarabine containing induction, including the recent Medical Research Council AML15 fludarabine, cytarabine, idaraubicin and G-CSF (FLAG-Ida) arm, and, despite higher anti-leukemic efficacy, only a minority of patients is able to complete the full planned program. In this article, we show that our therapeutic program is generally well tolerated, as most patients were able to receive subsequent therapy at full dose and in a timely manner, with a 30-day mortality of 4.8%. The omission of fludarabine in the second course did not reduce efficacy, as a CR rate of 83% was achieved and 3-year disease-free survival and overall survival (OS) were 49.6% and 50.9%, respectively. Our experience shows that FLAI-5/Ara-C + Ida double induction followed by risk-oriented consolidation therapy can result in good overall outcome with acceptable toxicity. Am. J. Hematol. 91:755-762, 2016. © 2016 Wiley Periodicals, Inc.

Transplantation from haploidentical donor is not inferior to that from identical sibling donor for patients with chronic myeloid leukemia in blast crisis or chronic phase from blast crisis

OBJECTIVES

Allogeneic hematopoietic stem cell transplantation (HSCT) is the only curative therapy for chronic myeloid leukemia (CML) patients in blast crisis (BC), and haploidentical donors (HID) are immediately available for most patients. We compared the outcomes of HID transplantation with those of matched related donor (MRD) transplantation in a cohort study.

PATIENTS AND METHODS

A total of 90 consecutive patients who received allogeneic HSCT because of CML-BC were investigated retrospectively. A total of 67 patients underwent transplantation from HID and 23 from MRD. Survival outcomes were compared between the two cohorts.

RESULTS

Of the 90 patients, 86 patients were engrafted. Three-year overall survival (OS) and relapse-free survival (RFS) were comparable between HID and MRD recipients (OS: 60.0% vs 55.3%, respectively, P=.580; RFS: 51.1% vs 47.8%, respectively, P=.512). Three-year incidences of transplant-related mortality (TRM) and relapse did not differ between HID and MRD recipients (relapse: 21.0% vs 26.1%, respectively, P=.626; TRM: 27.9% vs 26.1%, respectively, P=.937). In multivariate analyses, previous chemotherapy history and not achieving CHR before HSCT are independent adverse predictors of OS.

CONCLUSIONS

For CML-blast crisis or chronic phase from blast crisis patients, HID transplantation achieves comparable survival to MRD transplantation. HID donors can be regarded as regular donors for these special patients at selected centers.

Haploidentical Stem Cell Transplantation in Adult Haematological Malignancies

Haematopoietic stem cell transplantation is a well-established treatment option for both hematological malignancies and nonmalignant conditions such as aplastic anemia and haemoglobinopathies. For those patients lacking a suitable matched sibling or matched unrelated donor, haploidentical donors are an alternative expedient donor pool. Historically, haploidentical transplantation led to high rates of graft rejection and GVHD. Strategies to circumvent these issues include T cell depletion and management of complications thereof or T replete transplants with GVHD prophylaxis. This review is an overview of these strategies and contemporaneous outcomes for hematological malignancies in adult haploidentical stem cell transplant recipients.

Comparison of Outcomes after Peripheral Blood Haploidentical versus Matched Unrelated Donor Allogeneic Hematopoietic Cell Transplantation in Patients with Acute Myeloid Leukemia: A Retrospective Single-Center Review

Recent studies comparing allogeneic hematopoietic cell transplantation (HCT) using HLA-matched unrelated donors (MUD) versus HLA-haploidentical donors in patients with acute myeloid leukemia (AML) have suggested equivalent outcomes. The graft source used in most studies of haploidentical transplants has been bone marrow. Similar comparisons between MUD and haplo-HCT using peripheral blood as a graft source have not been adequately performed. We reviewed the records of all 52 AML patients who underwent haplo-HCT (using peripheral blood and post-transplantation high-dose cyclophosphamide) between January 2010 and August 2015 at our institution and compared their outcomes with 88 patients who had a MUD transplant in the same time frame and were frequency matched (preanalysis) to the haploidentical group for conditioning intensity. Multivariate analysis found no difference in outcomes between the 2 groups with the exception of slower count recovery after haploidentical allografts (HR, .48; 95% CI, .32 to .74 for platelets, and HR, .47; 95% CI, .32 to .71 for neutrophils; P < .001 for both comparisons). Our retrospective analysis, although limited by the small sample size, suggests largely similar outcomes with peripheral blood haploidentical versus MUD transplants for AML.

Haploidentical hematopoietic stem cell transplantation with post-transplant high-dose cyclophosphamide in high-risk children: A single-center study

Recently, haploidentical transplantations have been performed with unmanipulated BM or PBSC. This approach is becoming more widely adopted with the use of PTCY. However, there is limited evidence about this approach in children. We present 15 children who received 16 haploidentical HSCT with unmanipulated BM or PBSC using PTCY for GVHD prophylaxis. Post-transplant CY(50 mg/kg IV) was given on the third and fifth day, and CsA or tacrolimus with MMF or MP was also used for GVHD prophylaxis. All patients engrafted at a median of 16 and 18 days for neutrophil and thrombocyte recovery, respectively. Grades II-III acute GVHD developed in seven patients, and mild chronic GVHD was found in two patients. Two patients died within the first 100 days due to sepsis (TRM 12.5%). Eleven patients are currently alive, with a median follow-up of 12 months (range 6-22 months). The 12-month OS and DFS were 75 ± 10.8% and 68.8 ± 11.6%, respectively. Our results with these high-risk patients are encouraging for haploidentical HSCT in pediatric patients. Future studies should continue to assess haploidentical HSCT, including comparison of other modalities, in a primary pediatric population.

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.

How do we choose the best donor for T-cell-replete, HLA-haploidentical transplantation?

In haploidentical stem cell transplantations (haplo-SCT), nearly all patients have more than one donor. A key issue in the haplo-SCT setting is the search for the best donor, because donor selection can significantly impact the incidences of acute and chronic graft-versus-host disease, transplant-related mortality, and relapse, in addition to overall survival. In this review, we focused on factors associated with transplant outcomes following unmanipulated haplo-SCT with anti-thymocyte globulin (ATG) or after T-cell-replete haplo-SCT with post-transplantation cyclophosphamide (PT/Cy). We summarized the effects of the primary factors, including donor-specific antibodies against human leukocyte antigens (HLA); donor age and gender; killer immunoglobulin-like receptor-ligand mismatches; and non-inherited maternal antigen mismatches. We also offered some expert recommendations and proposed an algorithm for selecting donors for unmanipulated haplo-SCT with ATG and for T-cell-replete haplo-SCT with PT/Cy.

HLA Haplotype Mismatch Transplants and Posttransplant Cyclophosphamide

The use of high dose posttransplant cyclophosphamide (PT-CY) introduced by the Baltimore group approximately 10 years ago has been rapidly adopted worldwide and is becoming a standard for patients undergoing unmanipulated haploidentical (HAPLO) transplants. PT-CY has been used following nonmyeloablative as well as myeloablative conditioning regimens, for bone marrow or peripheral blood grafts, for patients with malignant and nonmalignant disorders. Retrospective comparisons of HAPLO grafts with conventional sibling and unrelated donor grafts have been published and suggest comparable outcome. The current questions to be answered include the use of PT-CY for sibling and unrelated donors transplant, possibly in the context of prospective randomized trial.