Outcome of haploidentical versus matched sibling donors in hematopoietic stem cell transplantation for adult patients with acute lymphoblastic leukemia: a study from the Acute Leukemia Working Party of the European Society for Blood and Marrow Transplantation.

BACKGROUND: Non-T-cell depleted haploidentical hematopoietic stem cell transplantation (HaploSCT) is being increasingly used in acute lymphoblastic leukemia (ALL) with improving patient outcomes. We have recently reported that outcomes of adult patients (pts) with ALL in complete remission (CR) receiving HaploSCT are comparable to unrelated donor transplants. We now compared HaploSCT and matched sibling donor (MSD) transplants in pts with ALL. AIM: To assess transplantation outcomes of HaploSCT and MSD transplants in pts with ALL in CR. METHODS: We retrospectively analyzed adult patients (≥ 18 years) with ALL who underwent their first allogeneic stem cell transplantation (alloSCT) in first or second CR between 2012 and 2018, either from a T cell replete Haplo or MSD donor, and whose data were reported to the Acute Leukemia Working Party (ALWP) of the European Society for Blood and Marrow Transplantation (EBMT). Multivariate analysis (MVA) adjusting for differences between the groups was performed using the Cox proportional hazards regression model. Propensity score matching was also performed to reduce confounding effects. RESULTS: The analysis comprised 2304 patients: HaploSCT-413; MSD-1891. Median follow-up was 25 months. Median age was 37 (range 18-75) and 38 (18-76) years in HaploSCT and MSD, respectively. HaploSCT patients were transplanted more recently than those transplanted from MSD (2016 vs 2015, p < 0.0001). A higher rate of HaploSCT was in CR2 (33.4% vs 16.7%, p < 0.0001), respectively, and fewer received myeloablative conditioning (68% vs 83.2%, p < 0.0001). Cytomegalovirus (CMV) seropositivity was lower in HaploSCT patients (22% vs 28%, p = 0.01) and donors (27.1% vs 33%, p < 0.02), and a higher proportion of the HaploSCTs were performed using a bone marrow (BM) graft (46.2% vs 18.6%, p < 0.0001). The 2 groups did not differ with regard to gender, Karnofsky performance status score, ALL phenotype, Philadelphia chromosome (Ph) positivity and pre-alloSCT measurable residual disease (MRD). Graft versus host disease (GVHD) prophylaxis was mainly post-transplant cyclophosphamide (PTCy) based (92.7%) in the HaploSCT setting, while it was mostly pharmacologic in the setting of MSD (18.7% received ATG). Cumulative incidence of engraftment at day 60 was higher in MSD transplants compared to HaploSCT (98.7% vs 96.3%, p = 0.001), respectively. Day 180 incidence of acute (a) GVHD II-IV and III-IV was higher in HaploSCT vs. MSD: 36.3% vs 28.9% (p = 0.002 and 15.2% vs 10.5% (p = 0.005), respectively. Conversely, the 2-year chronic (c) GVHD and extensive cGVHD were 32% vs 38.8% (p = 0.009) and 11.9% vs 19.5% (p = 0.001) in HaploSCT vs MSD, respectively. Main causes of death were leukemia (31.8% vs 45%), infection (33.1% vs 19.7%) and GVHD (16.6% vs 19.7%) for HaploSCT and MSD, respectively. Two-year relapse incidence (RI), non-relapse mortality (NRM), leukemia-free survival (LFS), overall survival (OS) and GVHD-free, relapse-free survival (GRFS) were 26% vs 31.6%, 22.9% vs 13%, 51% vs 55.4%, 58.8% vs 67.4% and 40.6% vs 39% for HaploSCT and MSD, respectively. In the MVA, RI was significantly lower in HaploSCT in comparison with MSD, hazard ratio (HR) = 0.66 (95% CI 0.52-0.83, p = 0.004), while NRM was significantly higher, HR = 1.9 (95% CI 1.43-2.53, p < 0.0001). aGVHD grade II-IV and grade III-IV were higher in HaploSCT than in MSD HR = 1.53 (95% CI 1.23-1.9, p = 0.0002) and HR = 1.54 (95% CI 1.1-2.15, p = 0.011), respectively. Extensive cGVHD was lower in HaploSCT compared with MSD, HR = 0.61 (95% CI 0.43-0.88, p = 0.007), while total cGVHD did not differ significantly, HR = 0.94 (95% CI 0.74-1.18, p = 0.58). LFS, OS and GRFS did not differ significantly between the 2 transplant groups, HR = 0.96 (95% CI 0.81-1.14, p = 0.66); HR = 1.18 (95% CI 0.96-1.43, p = 0.11) and HR = 0.93 (95% CI 0.79-1.09, p = 0.37), respectively. These results were confirmed in a matched-pair analysis. CONCLUSIONS: Outcomes of adult patients with ALL in CR receiving alloSCT from haploidentical donors are not significantly different from those receiving transplants from MSD in terms of LFS, OS and GRFS.

Haploidentical related donor compared to HLA-identical donor transplantation for chemosensitive Hodgkin lymphoma patients.

BACKGROUND: Allogeneic stem cell transplantation from haploidentical donor using an unmanipulated graft and post-transplantation cyclophosphamide (PT-Cy) is growing. Haploidentical transplantation with PT-Cy showed a major activity in Hodgkin lymphoma (HL), reducing the relapse incidence. The most important predictive factor of survival and toxicity was disease status before transplantation, which was better in patients with well controlled disease. METHODS: We included 198 HL in complete (CR) or partial remission (PR) before transplantation. Sixty-five patients were transplanted from haploidentical donor and 133 from a HLA identical donor (both sibling and unrelated donors). Survival analysis was defined according to the EBMT criteria. Survival curves were generated by using Kaplan-Meier method and differences between groups were compared by the log rank test or by the log rank test for trend when appropriated. RESULTS: The PFS, OS, and RI were significantly better in patients in CR compared to PR (55% vs 29% p = 0.001, 74% vs 55% p = 0.03, 27% vs 55% p <  0.001, respectively). The 2-year PFS was significantly better for HAPLO than HLA-id (63% vs 37%, p = 0.03), without difference in OS. The 1-year NRM was not different. The 2-year relapse incidence (RI) was lower in the HAPLO group (24% vs 44%, p = 0.008). Patients in CR receiving haplo HSCT showed higher 2-year PFS and lower 2-year RI than those allografted with HLA-id donor (75% vs 47%, p <  0.001 and 11% vs 34%, p < 0.001, respectively). In multivariate analysis, donor type and disease status before transplantation were independent predictors of PFS as well as they predict the risk of relapse. Disease status at transplantation and age were independently associated to OS. CONCLUSIONS: Nonetheless this is a retrospective study, limiting the wide applicability of results, data from this analysis suggest that HLA mismatch can induce a strong graft versus lymphoma effect leading to an enhanced PFS.

Haploidentical transplantation using posttransplant cyclophosphamide as GVHD prophylaxis in patients over age 70.

Hematologic malignancies in older people are unlikely to be cured with chemotherapy alone. Advances in allogeneic blood or marrow transplantation (alloBMT), especially nonmyeloablative (NMA) conditioning and the use of haploidentical donors, now make this therapy available to older people; however, long-term outcomes and predictors of success are unclear. We reviewed the outcomes of 93 consecutive patients aged 70 and older (median, 72; range, 70-78), who underwent haploidentical BMT at Johns Hopkins Hospital between 1 September 2009 and 1 April 2018. All patients received NMA conditioning and posttransplantation cyclophosphamide (PTCy) as graft-versus-host disease (GVHD) prophylaxis. The 2-year overall survival was 53%, and 2-year event-free survival was 43%. The 180-day cumulative incidence (CuI) of nonrelapse mortality (NRM) was 14%, and the 2-year CuI was 27%. The 2-year CuI of relapse was 30%. Of 78 patients who were alive and had their weight recorded on day 180, weight loss predicted subsequent NRM (subdistribution hazard ratio, 1.0; 95% CI, 1-1.13; P = .048). In conclusion, haploidentical BMT with PTCy is feasible and relatively safe in septuagenarians. Although early, 6-month NRM was relatively low at 14%, but overall NRM continued to climb to 27% at 2 years, at least in part because of late deaths that appeared to be somewhat age related. Further studies to elucidate predictors of NRM are warranted.

Comparison of Outcomes of Frontline Immunosuppressive Therapy and Frontline Haploidentical Hematopoietic Stem Cell Transplantation for Children with Severe Aplastic Anemia Who Lack an HLA-Matched Sibling Donor.

We compared the outcomes of immunosuppressive therapy (IST) with those of T cell-replete haploidentical donor hematopoietic stem cell transplantation (haplo-HSCT) in children and adolescents with severe aplastic anemia (SAA). The medical records of 49 patients with SAA who received frontline IST (n = 29) or frontline haplo-HSCT (n = 20) between 2012 and 2016 were analyzed retrospectively. Fourteen patients responded after the first IST, and 1 patient responded after the second IST in the frontline IST group; 12 patients underwent salvage HSCT after IST failure. Sixteen of the 20 patients who underwent frontline haplo-HSCT survived without treatment failure. The 3-year overall survival of the frontline IST group was comparable to that of the frontline haplo-HSCT group (79.3 ± 7.5% versus 85.0 ± 8.0%; χ2 = 0.110; P = .740). The 3-year failure-free survival was lower in the frontline IST group compared with the frontline haplo-HSCT group (35.9 ± 10.9% versus 80.0 ± 8.9%; χ2 = 4.089; P = .043). Five patients of the IST group who underwent salvage HSCT achieved long survival without event. The event-free survival was lower in the salvage HSCT group compared with the haplo-HSCT group (41.7 ± 14.2% versus 80.0 ± 8.9%; χ2 = 3.992; P = .046), and the incidences of acute GVHD, grade II-IV acute GVHD, chronic GVHD, and severe infection were comparable between the 2 groups. Our results suggest that frontline haplo-HSCT may be a better treatment than IST for children and adolescents with SAA who lack an HLA age-matched familial donor.

Effects of Low-Dose Glucocorticoid Prophylaxis on Chronic Graft-versus-Host Disease and Graft-versus-Host Disease-Free, Relapse-Free Survival after Haploidentical Transplantation: Long-Term Follow-Up of a Controlled, Randomized Open-Label Trial.

This long-term follow-up study evaluated the effects of corticosteroid prophylaxis on graft-versus-host disease (GVHD)-free, relapse-free survival (GRFS) based on a controlled open-label randomized trial in which 228 allotransplant recipients were categorized as low risk (n = 83, group A) or high risk; patients at high risk were randomly assigned to receive (n = 72, group B) or not receive (n = 73, group C) low-dose methylprednisolone prophylaxis. The cumulative incidences of chronic GVHD, relapse, nonrelapse mortality, leukemia-free survival, overall survival, and GRFS were 60%, 19%, 16%, 68%, 73%, and 46%, respectively, in all cases. Compared with the patients in group C, the cases in group B experienced a lower cumulative incidence of moderate to severe chronic GVHD (42% versus 20%; P = .010), herpes zoster infection (28% versus 12%; P = .010), pulmonary infections (42% versus 21%; P = .040), and osteonecrosis of the femoral head (ONFH; 16% versus 6%; P = .045) as well as better GRFS (59% versus 33%; P = .017). Factors associated with GRFS included total dose of corticosteroid used in the first 100days after transplantation (hazard ratio, 1.547; P = .015) and platelet recovery (hazard ratio, 1.456; P = .037). Our results suggest that low-dose glucocorticoid prophylaxis reduces GVHD and thus reduces the total dose of steroids, which might contribute to lower incidence of infections and ONFH and a superior GRFS, indicating that higher steroid doses are harmful. Reducing the total dose is of course beneficial. (ClinicalTrials.gov number, NCT01607580.).

Haploidentical transplantation is associated with better overall survival when compared to single cord blood transplantation: an EBMT-Eurocord study of acute leukemia patients conditioned with thiotepa, busulfan, and fludarabine.

BACKGROUND: Thiotepa-busulfan-fludarabine (TBF) is a widely used conditioning regimen in single umbilical cord blood transplantation (SUCBT). More recently, it was introduced in the setting of non-T cell depleted haploidentical stem cell transplantation (NTD-Haplo). Whether TBF based conditioning provides additional benefit in transplantation from a particular alternative donor type remains to be established. METHODS: This was a retrospective study based on an international European registry. We compared outcomes of de-novo acute myeloid leukemia patients in complete remission receiving NTD-Haplo (n = 186) vs. SUCBT (n = 147) following myeloablative conditioning (MAC) with TBF. Median follow-up was 23 months. Treatment groups resembled in baseline characteristics. RESULTS: SUCBT was associated with delayed engraftment and higher graft failure. In multivariate analysis no statistically significant differences were observed between the two groups in terms of acute or chronic graft-versus-host disease (GvHD) (HR = 1.03, p = 0.92 or HR = 1.86, p = 0.21) and relapse incidence (HR = 0.8, p = 0.65). Non-relapse mortality (NRM) was significantly higher in SUCBT as compared to NTD-Haplo (HR = 2.63, p = 0.001); moreover, SUCBT did worse in terms of overall survival (HR = 2.18, p = 0.002), leukemia-free survival (HR = 1.94, p = 0.007), and GvHD relapse-free survival (HR = 2.38, p = 0.0002). CONCLUSIONS: Our results suggest that TBF-MAC might allow for a potent graft-versus-leukemia, regardless of the alternative donor type. Furthermore, in patients receiving TBF-MAC, survival with NTD-Haplo may be better compared to SUCBT due to decreased NRM.

Peripheral Blood Grafts for T Cell-Replete Haploidentical Transplantation Increase the Incidence and Severity of Cytokine Release Syndrome.

T cell-replete post-transplant cyclophosphamide (PTCy)-based protocols have led to increasing use of haploidentical allogeneic hematopoietic cell transplantation (haploHCT). With this approach, bidirectional alloreactivity causing nonengraftment or severe graft-versus-host disease (GVHD) is no a longer major barrier to haploHCT. PTCy eliminates alloreactive lymphocytes but spares CD34+ stem cells and regulatory T lymphocytes, resulting in reliable hematopoietic recovery with relatively low incidence of GVHD. The immediate post-haploHCT course, usually before PTCy administration, is often complicated by cytokine release syndrome (CRS). The predictors of CRS and its effect on outcomes post-transplant have not been fully ascertained. We analyzed the outcomes of 66 patients who received haploHCT at our institution. Using published CRS criteria we identified 48 patients who developed CRS. In multivariate analysis peripheral blood grafts were significantly associated with grade ≥ 2 CRS, compared with bone marrow. Grade ≥ 2 CRS (compared with grade < 2) was not associated with differences in overall survival or nonrelapse mortality. Severe CRS was associated with a statistically nonsignificant trend toward higher incidences of grades III to IV acute GVHD, especially in the context of peripheral blood grafts. CRS is a common complication after T cell-replete peripheral blood haploHCT, but post-transplant survival outcomes may not be affected in those with severe CRS.

Cost-effectiveness analysis of haploidentical vs matched unrelated allogeneic hematopoietic stem cells transplantation in patients older than 55 years.

Due to limited donor availability, high comorbidities, and cost issues, allogeneic hematopoietic stem cell transplant is not universally accessible. The aim of this study was to conduct a cost-effectiveness analysis of haploidentical vs matched unrelated transplant. This retrospective study included patients with hematological malignancies older than 55 years who underwent haploidentical or matched unrelated transplant between 2011 and 2013 in Marseille. The incremental cost-effectiveness ratio has been calculated using the mean overall survival and the mean transplant costs. Costs were calculated using a micro-costing strategy from the hospital perspective and a time horizon at 2 years. Haploidentical transplant was considered an innovative procedure and matched unrelated transplant as the reference. Probabilistic and sensitivity analyses were performed on the incremental cost-effectiveness ratio. During inclusion, 29 patients underwent haploidentical transplant and 63 matched unrelated transplant. In haploidentical and matched unrelated transplant, the mean overall survival was 19.4 (1.6) months and 15.1 (1.2) months (p = 0.06), respectively, and the mean cost was 98,304 (40,872) € and 151,373 (65,742) € (p < 0.01), respectively. The incremental cost-effectiveness ratio was assessed to -148,485 (-1,265,550; -64,368) € per life year gained. Among older patients suffering from hematological malignancies, haploidentical transplant seemed in our analysis to be cost-effective compared with matched unrelated transplant.

Effect of donor characteristics on haploidentical transplantation with posttransplantation cyclophosphamide.

We studied the association between non-HLA donor characteristics (age, sex, donor-recipient relationship, blood group [ABO] match, and cytomegalovirus [CMV] serostatus) and transplant outcomes after T-cell-replete HLA-haploidentical transplantation using posttransplantation cyclophosphamide (PT-Cy) in 928 adults with hematologic malignancy transplanted between 2008 and 2015. Siblings (n = 358) and offspring (n = 450) were the predominant donors, with only 120 patients having received grafts from parents. Although mortality risks were higher with donors aged 30 years or older (hazard ratio, 1.39; P < .0001), the introduction of patient age to the Cox regression model negated the effect of donor age. Two-year survival adjusted for CMV seropositivity, disease, and disease risk index was lower in patients aged 55 to 78 years after transplantation of grafts from donors younger than 30 years (53%) or aged at least 30 years (46%) compared with younger patients who received grafts from donors younger than 30 years (61%) and at least 30 years (60%; P < .0001). Similarly, 2-year survival in patients aged 55 to 78 years was lower after transplantation of grafts from siblings (45%) or offspring (48%) compared with patients aged 18 to 54 years after transplantation of grafts from siblings (62%), offspring (58%), and parents (61%; P < .0001). Graft failure was higher after transplantation of grafts from parents (14%) compared with siblings (6%) or offspring (7%; P = .02). Other non-HLA donor characteristics were not associated with survival or graft failure. The current analyses suggest patient and disease, rather than non-HLA donor characteristics, predominantly influence survival in adults.

Superior Survival of Black Versus White Patients Following Post-Transplant Cyclophosphamide-Based Haploidentical Transplantation for Adults with Hematologic Malignancy.

Available evidence from large registry studies has shown inferior survival for black adult patients following both unrelated donor and cord blood transplantation. Post-transplant cyclophosphamide (PTCy)-based haploidentical donor transplantation (HIDT) is being increasingly used in ethnic minorities. However, no studies of the impact of race on outcomes following HIDT have been reported. We analyzed 203 consecutive patients (123 white, 80 black) who underwent first HIDT using PTCy for hematologic malignancy at a single institution. Median recipient age was 53 (range, 19-75) years. Peripheral blood stem cells (PBSCs) were used as the stem cell source in 66% of patients, and conditioning intensity was myeloablative (MA) in 41%. After a median follow-up of 36 months, the estimated 3-year overall survival (OS), disease-free survival (DFS), and cumulative incidence of relapse (CIR) were significantly better in black patients, compared with white patients (72% [95% confidence interval (CI), 60% to 81%], 65% [95% CI, 52% to 75%], and 25% [95% CI, 16% to 35] versus 50% [95% CI, 40% to 59%], 45% [95% CI, 36% to 54%], and 39% [95% CI, 31% to 47%], respectively; P < .001 for OS and DFS, P = .015 for CIR). In contrast, 3-year nonrelapse mortality was similar between black (11%) and white (16%) patients, as were the incidences of acute graft-versus-host disease (GVHD) and moderate-to-severe chronic GVHD. Improved survival was noted in all subgroups of black patients-younger versus older, male versus female, lower versus higher disease risk index, MA versus non-MA conditioning, or PBSC versus marrow stem cell source. In multivariate analysis, black race was independently associated with better OS (hazard ratio [HR], .47; P = .003), DFS (HR, .49; P = .003), and relapse (HR, .49; P = .01). Black patients achieve superior outcomes to their white counterparts following PTCy-based HIDT due to a decreased incidence of disease relapse.

Haploidentical Stem Cell Transplantation for Refractory/Relapsed Neuroblastoma.

Pediatric patients with refractory or relapsed metastatic neuroblastoma (NBL) have a poor prognosis despite autologous stem cell transplantation (SCT). Allogeneic SCT from a haploidentical donor has a remarkable alloreactive effect in patients with leukemia; thus, we evaluated this approach in children with very high-risk NBL. We analyzed data from 2 prospective phase I/II trials. A total of 26 patients with refractory (n = 5), metastatic relapsed (n = 20), or locally relapsed MYCN-positive (n = 1) NBL received a median of 17 × 106/kg T/B cell-depleted CD34+ stem cells with 68 × 103/kg residual T cells and 107 × 106/kg natural killer cells. The conditioning regimen comprised melphalan, fludarabine, thiotepa, OKT3, and a short course of mycophenolate mofetil post-transplantation. Engraftment occurred in 96% of the patients. Event-free survival and overall survival at 5 years were 19% and 23%, respectively. No transplantation-related mortality was observed, and the single death was due to progression/subsequent relapse. The median duration of follow-up was 8.1 years. Patients in complete remission before SCT had a significantly better prognosis than those with residual tumor load (P < .01). All patients with progressive disease before SCT relapsed within 1 year. Grade II and grade III acute graft-versus-host disease (GVHD) occurred in 31% and 12% of the patients, respectively. Chronic limited and extensive GVHD occurred in 28% and 10%, respectively. Our data indicate that haploidentical SCT is a feasible treatment option that can induce long-term remission in some patients with NBL with tolerable side effects, and may enable the development of further post-transplantation therapeutic strategies based on the donor-derived immune system.

Grade II Acute Graft-versus-Host Disease and Higher Nucleated Cell Graft Dose Improve Progression-Free Survival after HLA-Haploidentical Transplant with Post-Transplant Cyclophosphamide.

Compared with standard graft-versus-host disease (GVHD) prophylaxis platforms, post-transplantation cyclophosphamide (PTCy) after T cell-replete HLA-haploidentical (haplo) bone marrow transplantation (BMT) reduces the risk of grades III to IV acute (a) and chronic (c) GVHD, but maintains similar rates of grade II aGVHD. Given that mild GVHD has been associated with reduced treatment failure in HLA-matched BMT, we evaluated the risk factors for and effects of GVHD on survival in 340 adults with hematologic malignancies who engrafted after nonmyeloablative haplo-BMT with PTCy, mycophenolate mofetil, and tacrolimus. The cumulative incidence at 100 days of grade II and grades III to IV aGVHD were 30% (95% confidence interval [CI], 25% to 35%) and 2% (95% CI, 1% to 4%), respectively. The 1-year cumulative incidence of cGVHD was 10% (95% CI, 7% to 13%). In landmark analyses at 100 days, the 4-year probabilities of overall survival (OS) and progression-free survival (PFS) were, 48% (95% CI, 41% to 56%) and 39% (95% CI, 32% to 47%) for patients without grades II to IV aGVHD, compared with 63% (95% CI, 53% to 73%) and 59% (95% CI, 50% to 71%) for patients with grade II aGVHD (P = .05 and P = .009). In multivariable modeling, when compared with patients who never experienced GVHD, the hazard ratio (HR) for OS and PFS in patients with grade II aGVHD was .78 (95% CI, .54 to 1.13; P = .19) and .69 (95% CI, .48 to .98; P = .04). Higher nucleated cell graft dose was also associated with improved OS (HR, .88; 95% CI, .78 to 1.00; P = .05) and PFS (HR, .89; 95% CI, .79 to 1.0; P = .05) and decreased risk of grades III to IV aGVHD (subdistribution HR, .66; 95% CI, .46 to .96; P = .03). PTCy reduces grades III to IV aGVHD and cGVHD, but retains similar incidence of grade II aGVHD, the development of which improves PFS. Higher nucleated cell graft dose goals may also improve survival after nonmyeloablative haplo-BMT with PTCy.

Donor lymphocyte infusion and methotrexate for immune recovery after T-cell depleted haploidentical transplantation.

CD34+ cell selection minimizes graft-versus-host disease (GVHD) after haploidentical donor stem cell transplant but is associated with slow immune recovery and infections. We report a Phase I/II study of prophylactic donor lymphocyte infusion (DLI) followed by methotrexate (MTX) GVHD prophylaxis after CD34-selected haploidentical donor transplant. A prophylactic DLI was given between day +30 and +42. Rituximab was given with DLI for the last 10 patients. The goal of the study was to determine a DLI dose that would result in a CD4+ cell count > 100/µL at Day +120 in ≥ 66% of patients with ≤ 33% grade II-III, ≤ 17% grade III, and no grade IV acute GVHD by Day +180. Thirty-five patients with malignant (n = 25) or nonmalignant disease (n = 10) were treated after CD34-selected haploidentical donor peripheral blood stem cell transplant. The DLI dose of 5 × 104 /kg met the CD4/GVHD goal with 67% of patients having CD4+ cells > 100/µL and 11% grade II-IV acute GVHD. The cumulative incidence of chronic GVHD was 16%. Fatal viral and fungal infections occurred in 11%. The 2 year estimated overall survival was 69% and the relapse rate was 14% for patients in remission at transplant. There was no effect of NK alloreactivity on relapse. Nine of ten patients at the target DLI dose cohort of 5 × 104 /kg are alive with median follow-up of 18 mos (range 6-29). Delayed prophylactic DLI and MTX was associated with promising outcomes at the target DLI dose. This trial was registered at clinicaltrials.gov, # NCT01027702.

Impact of HLA Disparity in Haploidentical Bone Marrow Transplantation Followed by High-Dose Cyclophosphamide.

We studied the impact of HLA mismatching on the outcome of 318 consecutive patients who received an unmanipulated haploidentical bone marrow transplant, followed by post-transplant cyclophosphamide (PTCy). The number of HLA-mismatched antigens was tested for its impact on overall survival (OS) and nonrelapse mortality (NRM), whereas HLA mismatches in the graft-versus-host (GVH) direction were tested for prediction of graft-versus-host disease (GVHD and relapse. Finally, we studied whether graft rejection correlated with the number of HLA mismatched antigens in host-versus-graft (HVG) direction. Two hundred thirty-one donor-recipient pairs (72%) had 4/8 mismatches at the -A, -B, -C, -DRB1 HLA loci. HLA mismatches did not predict the 2-year OS (hazard ratio, .83; P = .58) and NRM (subhazard ratio, 1.08; P = .93). The cumulative incidence of acute GVHD (P = .13), 1-year chronic GVHD (P = .84), and relapse rate (P = .26) did not correlate with univectorial GVH mismatches. Similarly, no correlation was observed between the amount of HLA mismatch in the HVG direction and graft rejection. In multivariate analysis advanced disease at transplant was the strongest predictor of survival, NRM, relapse, and graft rejection. In conclusion, the degree of HLA mismatching should not be used as a criterion to select family haploidentical donors when using bone marrow as stem cell source and PTCy for GVHD prophylaxis.

Outcomes of haploidentical stem cell transplantation for chronic lymphocytic leukemia: a retrospective study on behalf of the chronic malignancies working party of the EBMT.

Allogeneic hematopoietic stem cell transplantation (HCT) may result in long-term disease control in high-risk chronic lymphocytic leukemia (CLL). Recently, haploidentical HCT is gaining interest because of better outcomes with post-transplantation cyclophosphamide (PTCY). We analyzed patients with CLL who received an allogeneic HCT with a haploidentical donor and whose data were available in the EBMT registry. In total 117 patients (74% males) were included; 38% received PTCY as GVHD prophylaxis. For the whole study cohort OS at 2 and 5 yrs was 48 and 38%, respectively. PFS at 2 and 5 yrs was 38 and 31%, respectively. Cumulative incidence (CI) of NRM in the whole group at 2 and 5 years were 40 and 44%, respectively. CI of relapse at 2 and 5 yrs were 22 and 26%, respectively. All outcomes were not statistically different in patients who received PTCY compared to other types of GVHD prophylaxis. In conclusion, results of haploidentical HCT in CLL seem almost identical to those with HLA-matched donors. Thereby, haploidentical HCT is an appropriate alternative in high risk CLL patients with a transplant indication but no available HLA-matched donor. Despite the use of PTCY, the CI of relapse seems not higher than observed after HLA-matched HCT.

Haploidentical Hematopoietic Stem Cell Transplantation for Myelodysplastic Syndrome.

This study aimed to validate the capability of the Center for International Blood and Marrow Transplant Research (CIBMTR) prognostic scoring system to predict outcomes of patients with myelodysplastic syndromes (MDS) who had undergone HLA-haploidentical related donor hematopoietic stem cell transplantation (haplo-HSCT). We also propose and validate a more suitable prognostic scoring system. A total of 157 patients with MDS who underwent haplo-HSCT were enrolled. The CIBMTR prognostic scoring system could predict the 2-year clinical outcomes, but failed to predict the 100-day clinical outcomes after haplo-HSCT. Our multivariable model identified 2 independent predictors of overall survival: age and monosomal karyotype (MK). Weighted scores of 5, 3, and 2 were assigned to age ≥50 years, age 30 to 49 years, and MK, respectively, and a 2-category system was created: low (score ≤3) and high (score >3). Our refined prognostic scoring system can predict both the 100-day and 2-year clinical outcomes after haplo-HSCT. Our findings indicate that the CIBMTR prognostic scoring system is predictive of the outcomes of patients with MDS following haplo-HSCT, and that older patients with MDS and/or patients with MK should be closely monitored after haplo-HSCT.

Reduced-Intensity Haploidentical Bone Marrow Transplantation with Post-Transplant Cyclophosphamide for Solid Tumors in Pediatric and Young Adult Patients.

High-risk, recurrent, or refractory solid tumors in pediatric, adolescent, and young adult (AYA) patients have an extremely poor prognosis despite current intensive treatment regimens. We piloted an allogeneic bone marrow transplant platform using reduced-intensity conditioning (RIC) and partially HLA-mismatched (haploidentical) related donors for this population of pediatric and AYA solid tumor patients. Sixteen patients received fludarabine, cyclophosphamide, melphalan, and low-dose total body irradiation RIC haploidentical BMT (haploBMT) followed by post-transplantation cyclophosphamide (PTCy), mycophenolate mofetil, and sirolimus. All assessable patients were full donor chimeras on day 30 with a median neutrophil recovery of 19 days and platelet recovery of 21 days. One patient (7%) exhibited secondary graft failure associated with concomitant infection. The median follow-up time was 15 months. Overall survival was 88%, 56%, and 21% at 6, 12, and 24 months, respectively. Median survival from transplant date was 14 months with a median progression-free survival 7 months. We observed limited graft-versus-host disease in 3 patients and nonrelapse mortality in 1 patient. We demonstrated that RIC haploBMT with PTCy is feasible and has acceptable toxicities in patients with incurable pediatric and AYA solid tumors; thus, this approach serves as a platform for post-transplant strategies to prevent relapse and optimize progression-free survival.

Haplo-Cord transplantation compared to haploidentical transplantation with post-transplant cyclophosphamide in patients with AML.

For patients with AML, the best alternative donor remains to be defined. We analyze outcomes of patients who underwent myeloablative umbilical cord blood or haploidentical hemopoietic stem cell transplantation (HSCT) in Spain. Fifty-one patients underwent single umbilical cord blood transplantation supported by a third party donor (Haplo-Cord) between 1999 and 2012, and 36 patients received an haploidentical HSCT with post-transplant cyclophosphamide (PTCY-haplo) between 2012 and 2014 in GETH centers. The Haplo-Cord cohort included a higher proportion of patients with high disease risk index and use of TBI in the conditioning regimen, and hematopoietic cell transplantation-age Comorbidity Age Index was higher in PTCY-haplo patients. Cumulative incidence of neutrophil engraftment was 97% in the Haplo-Cord and 100% in the PTCY-haplo group, achieved in a median of 12 and 17 days, respectively (P=0.01). Grade II-IV acute GvHD rate was significantly higher in the PTCY-haplo group (9.8% vs 29%, P=0.02) as well as chronic GvHD rates (20% vs 38%, P=0.03). With a median follow-up of 61 months for the Haplo-Cord group and 26 months for the PTCY-haplo cohort, overall survival at 2 years was 55% and 59% (P=0.66), event-free survival was 45% vs 56% (P=0.46), relapse rate was 27% vs 21% (P=0.79), and non-relapse mortality was 17% vs 23% (P=0.54), respectively. In this multicenter experience, Haplo-Cord and PTCY-haplo HSCT offer valid alternatives for patients with AML. Neutrophil engraftment was faster in the Haplo-Cord cohort, with similar survival rates, with higher GvHD rates after haploidentical HSCT.

Haploidentical Related Donor Hematopoietic Stem Cell Transplantation for Dedicator-of-Cytokinesis 8 Deficiency Using Post-Transplantation Cyclophosphamide.

Dedicator-of-cytokinesis 8 (DOCK8) deficiency, a primary immunodeficiency disease, can be reversed by allogeneic hematopoietic stem cell transplantation (HSCT); however, there are few reports describing the use of alternative donor sources for HSCT in DOCK8 deficiency. We describe HSCT for patients with DOCK8 deficiency who lack a matched related or unrelated donor using bone marrow from haploidentical related donors and post-transplantation cyclophosphamide (PT/Cy) for graft-versus-host disease (GVHD) prophylaxis. Seven patients with DOCK8 deficiency (median age, 20 years; range, 7 to 25 years) received a haploidentical related donor HSCT. The conditioning regimen included 2 days of low-dose cyclophosphamide, 5 days of fludarabine, 3 days of busulfan, and 200 cGy total body irradiation. GVHD prophylaxis consisted of PT/Cy 50 mg/kg/day on days +3 and +4 and tacrolimus and mycophenolate mofetil starting at day +5. The median times to neutrophil and platelet engraftment were 15 and 19 days, respectively. All patients attained >90% donor engraftment by day +30. Four subjects developed acute GVHD (1 with maximum grade 3). No patient developed chronic GVHD. With a median follow-up time of 20.6 months (range, 9.5 to 31.7 months), 6 of 7 patients are alive and disease free. Haploidentical related donor HSCT with PT/Cy represents an effective therapeutic approach for patients with DOCK8 deficiency who lack a matched related or unrelated donor.