Severe regimen-related toxicity of second transplantation for graft failure following reduced-intensity cord blood transplantation in an adult patient

Outcomes of salvage haploidentical transplantation using posttransplant cyclophosphamide for graft failure following allogeneic hematopoietic stem cell transplantation

Haploidentical donors have emerged as an alternative donor source for salvage stem cell transplantation (SCT) after graft failure; however, data regarding salvage haploidentical SCT using posttransplant cyclophosphamide (PTCy) are limited. Using nationwide data (2011-2019), we retrospectively investigated transplant outcomes after salvage haploidentical SCT using PTCy for graft failure (n = 33, median age 34 years). The total dose of PTCy was 75-100 mg/kg (standard dose) in 26 patients (78.8%) and 40-50 mg/kg (lower dose) in 5 patients (15.2%). The neutrophil engraftment rate at 30 days was 81.8%. One-year overall survival (OS) and non-relapse mortality (NRM) rates were 47.4% and 46.0%, respectively. The standard-dose group exhibited better OS (61.1% vs. 0.0% at 1 year, P = 0.022) and NRM (35.1% vs. 80.0% at 1 year, P = 0.052) than the lower-dose group. Moreover, the standard-dose group was less prone to both grades II-IV (11.5% vs. 40.0%) and III-IV (0.0% vs. 40.0%) acute graft-versus-host disease (GVHD). Use of cyclophosphamide in previous SCT and conditioning did not affect OS or NRM. In conclusion, haploidentical salvage SCT using PTCy offers promising survival outcomes. Prospective studies are required to validate the efficacy of salvage haploidentical SCT using PTCy.

Prognostic factors in salvage transplantation for graft failure following allogeneic hematopoietic stem cell transplantation

Although graft failure (GF) is a fatal complication after allogeneic stem cell transplantation (SCT), no mortality risk assessments after salvage SCT have been reported. We developed a comprehensive prognostic scoring system consisting of patient and comorbidity factors with 470 patients as a training cohort out of 940; these patients underwent salvage SCT for GF. The multivariate analysis demonstrated that older age, poorer performance status, a continuation of antimicrobial treatment, and severe organ dysfunction were independently associated with worse overall survival (OS) and non-relapse mortality (NRM). Based on each factor's hazard ratio, weighted scores of 1-3 were assigned to these factors. Using the summed scores (0-8), a prognostic scoring system successfully stratified outcomes after salvage SCT in the cohort. For patients in the low (0-2, n = 122), intermediate (3-4, n = 209), and high score (5-8, n = 110) groups, the 1-year OS was 62.8%, 40.8%, and 14.2%, respectively (P < 0.001), whereas the 1-year NRM was 24.1%, 43.9%, and 72.7%, respectively (P < 0.001). The prognostic value of the scoring system was confirmed in the validation cohort (n = 470). Our scoring system is useful for predicting survival after salvage SCT.

Comparison of immunosuppressant regimens in salvage cord blood transplantation for graft failure after allogeneic hematopoietic stem cell transplantation

Graft failure (GF) is a life-threatening complication after allogeneic stem cell transplantation. Although salvage cord blood transplantation (CBT) is a curative therapy for GF, the optimal immunosuppression after salvage CBT remains unknown. Using nationwide registration data, we compared the transplant outcomes of patients who developed GF and underwent salvage CBT using immunosuppressants, including calcineurin (CNI) alone (n = 177); CNI plus methotrexate (CNI+MTX, n = 150); and CNI plus mycophenolate mofetil (CNI+MMF, n = 161). The CNI+MMF group, in comparison with the CNI+MTX and CNI alone groups, demonstrated better neutrophil recovery at 30 days (62.7 vs. 42.7 vs. 53.1%, P < 0.001); better overall survival (OS) at 12 months (48.4 vs. 33.5 vs. 28.3%, P < 0.001); and lower non-relapse mortality (NRM) at 12 months (35.2 vs. 53.9 vs. 56.5%, P < 0.001). On multivariate analysis, CNI+MMF had the best neutrophil recovery (hazard ratio (HR), 1.71; P < 0.001) and OS (HR, 0.64; P = 0.002) and the lowest NRM (HR, 0.53; P < 0.001). Hemorrhage was relatively less frequent in the CNI+MMF group. CNI+MMF can be a promising immunosuppressant regimen after salvage CBT for GF, with better engraftment and survival outcomes, compared with CNI alone and CNI+MTX.

Comparison of the outcomes after haploidentical and cord blood salvage transplantations for graft failure following allogeneic hematopoietic stem cell transplantation

Graft failure (GF) is a life-threatening complication after allogeneic stem cell transplantation (SCT). Although salvage SCTs can be performed with haploidentical donor (HID) or cord blood (CB), no study has compared the performances of these two sources. Using nationwide registration data, we compared the transplant outcomes of patients who developed GF and underwent salvage transplantation from HID (n = 129) and CB (n = 570) from 2007 to 2016. The HID group demonstrated better neutrophil recovery (79.7 vs. 52.5% at 30 days, P < 0.001). With a median follow-up of 3 years, both groups demonstrated similar overall survival (OS) and nonrelapse mortality (NRM; 1-year OS, 33.1 vs. 34.6% and 1-year NRM, 45.1 vs. 49.8% for the HID and CB groups). After adjustments for other covariates, OS did not differ in both groups. However, HID was associated with a lower NRM (hazard ratio, 0.71; P = 0.038) than CB. The incidence of acute graft-versus-host disease (GVHD)-related deaths was significantly higher in the HID group, although infection-related deaths were observed more frequently in the CB group. HID may be a promising salvage SCT option after GF due to its faster engraftment and low NRM.

Comparative analysis of graft-versus-host disease prophylaxis with tacrolimus in combination with methylprednisolone or methotrexate after umbilical cord blood transplantation

Post-transplant early immune disorders and engraftment failure/delay are major issues in unrelated umbilical cord blood transplantation (UCBT). We evaluated graft-versus-host disease (GVHD) prophylaxis approaches after UCBT by comparing UCBT outcomes with GVHD prophylaxis using tacrolimus plus methylprednisolone (Tac/mPSL, n = 32) to that with Tac plus methotrexate (Tac/MTX, n = 31) at a single pediatric transplantation center. The 30-day cumulative incidence rates of neutrophil engraftment and median neutrophil engraftment times in the Tac/mPSL and Tac/MTX groups were 70.1% and 90.3% and 19 and 17 days, respectively (p = 0.09). Pre-engraftment immune reactions (PIR) and acute GVHD were improved with Tac/MTX; PIR incidence (p = 0.020) and cumulative incidence of 100-day acute GVHD (grade II-IV, 38.7% vs 68.8%, p = 0.045; grade III-IV, 9.7% vs 34.4%, p = 0.021) were significantly lower in the Tac/MTX group than in the Tac/mPSL group. However, the incidence rates of relapse (p = 0.921) and cytomegalovirus reactivation (p = 0.908), and the estimated overall (p = 0.87) and event-free survival (p = 0.88) were comparable between the two groups. These data indicate that GVHD prophylaxis with Tac/MTX is associated with favorable results, including reduced PIR and acute GVHD incidence after UCBT, without adverse effects.

Feasibility of salvage cord blood transplantation using a fludarabine, melphalan, and low-dose anti-thymocyte globulin conditioning regimen

Primary graft failure (PGF) is a lethal complication that occurs early after allogeneic stem cell transplantation (allo-SCT). Cord blood transplantation (CBT) is a potential re-transplantation option. Total body irradiation (TBI) is often incorporated into the pre-salvage CBT conditioning regimen following PGF; however, patients experiencing PGF are not always amenable to TBI, and non-TBI regimens for salvage CBT should be established. Here, we report five patients with hematologic malignancies who received salvage CBT for PGF following a non-TBI regimen using fludarabine (Flu), melphalan (Mel), and low-dose anti-thymocyte globulin (ATG). The median intervals between the failed allo-SCT and salvage CBT, as well as between the diagnosis of PGF and salvage CBT, were 37 days and 8 days, respectively. The median neutrophil recovery period was 21 days (range 18-21 days). Four of five patients achieved neutrophil engraftment following salvage CBT; all four exhibited sustained engraftment with complete donor chimerism. Three of the five patients were alive after a median follow-up time of 907 days (range 315-909 days) post-salvage CBT; two patients died of causes unrelated to recurrence. These data suggest that CBT following the non-TBI regimen described here is feasible in patients with PGF.

Alemtuzumab, Fludarabine, Low-Dose TBI, and Double Umbilical Cord Transplant for Primary Graft Failure in a Patient with Recurrent HLH

Graft failure occurs at relatively low frequency, but commonly in hemophagocytic lymphohistiocytosis (HLH), especially with umbilical cord blood transplant (UCBT). No standard approaches to management of graft failure exist. We present a challenging case of relapsed HLH following first UCBT with primary graft failure following second UCBT. We report a novel reduced intensity conditioning regimen of alemtuzumab, 4 Gy total body irradiation and fludarabine for salvage of primary graft failure followed by double UCBT. The reported patient successfully engrafted with 100% donor chimerism following salvage UCBT with no occurrence of acute or chronic graft-versus-host disease.

Feasibility of reduced-intensity cord blood transplantation as salvage therapy for graft failure: results of a nationwide survey of adult patients

To evaluate whether rescue with cord blood transplantation (CBT) could improve the poor survival after graft failure (GF), we surveyed the data of 80 adult patients (median age, 51 years) who received CBT within 3 months of GF (primary 64, secondary 16), with fludarabine-based reduced-intensity regimens with or without melphalan, busulfan, cyclophosphamide, and/or 2-4 Gy total-body irradiation (TBI). A median number of 2.4 × 10(7)/kg total nucleated cells (TNC) were infused, and among the 61 evaluable patients who survived for more than 28 days, 45 (74%) engrafted. The median follow-up of surviving patients was 325 days, and the 1-year overall survival rate was 33% despite poor performance status (2-4, 60%), carryover organ toxicities (grade 3/4, 14%), and infections (82%) prior to CBT. Day 100 transplantation-related mortality was 45%, with 60% related to infectious complications. Multivariate analysis showed that the infusion of TNC ≥2.5 × 10(7)/kg and an alkylating agent-containing regimen were associated with a higher probability of engraftment, and that high risk-status at the preceding transplantation and grade 3/4 organ toxicities before CBT were associated with an increased risk of mortality. In conclusion, in an older population of patients, our data support the feasibility of CBT with a reduced-intensity conditioning regimen for GF.

Unrelated cord blood transplantation in pediatric patients: a report from Saudi Arabia

In unrelated cord blood (UCB) transplantation, survival has been shown to correlate with the degree of HLA matching. Thus, to extend transplant access to different ethnic backgrounds, many western UCB transplantation banks now encourage donation from non-Caucasians. Until recently, Saudi Arabia did not have a national UCB bank. In this study we report our experience in UCB transplantation in children using units procured from western cord blood banks. A total of 97 children underwent unrelated UCB transplantation at King Faisal Specialist Hospital and Research Center (KFSHRC), of which 95 were of Arab ethnicity. A total of 30 patients had malignant disorders, 25 patients had non-malignant hematological disorders and 42 patients had inborn errors. Conditioning was according to disease, with six patients receiving reduced-intensity regimens. In all, 46 patients received one-Ag-mismatched units and 51 received two-Ag-mismatched units. Engraftment occurred in 93% of patients, the 100-TRM was 15%, acute GVHD developed in 20% of patients and chronic GVHD occurred in 9% of patients. The 5-year OS and EFS estimates were 52 and 43%, respectively. The search for UCB transplantation units for Saudi patients in western banks yielded reasonably compatible units for our patients; the results are consistent with published data. Our data are encouraging for UCB transplant programs in countries in which there are no national UCB transplantation banks.

Second unrelated donor hematopoietic cell transplantation for primary graft failure

Failure to engraft donor cells is a devastating complication after allogeneic hematopoietic cell transplantation (HCT). We describe the results of 122 patients reported to the National Marrow Donor Program between 1990 and 2005, who received a second unrelated donor HCT after failing to achieve an absolute neutrophil count of >or=500/microL without recurrent disease. Patients were transplanted for leukemia (n = 83), myelodysplastic disorders (n = 16), severe aplastic anemia (n = 20), and other diseases (n = 3). The median age was 29 years. Twenty-four patients received second grafts from a different unrelated donor. Among 98 patients who received a second graft from the same donor, 28 received products that were previously collected and cryopreserved for the first transplantation. One-year overall survival (OS) after second transplant was 11%, with 10 patients alive at last follow-up. We observed no differences between patients who received grafts from the same or different donors, or in those who received fresh or cryopreserved product. The outcomes after a second allogeneic HCT for primary graft failure are dismal. Identifying risk factors for primary graft failure can decrease the incidence of this complication. Further studies are needed to test whether early recognition and hastened procurement of alternative grafts can improve transplant outcomes for primary graft failure.

Short-term methotrexate could reduce early immune reactions and improve outcomes in umbilical cord blood transplantation for adults

Post transplant immune disorders are problematic in cord blood transplantation (CBT) for adult patients, and optimal prophylaxis has not been established. We investigated whether intensive graft-versus-host disease (GVHD) prophylaxis using short-term methotrexate (MTX) has a prognostic impact on CBT. Post-CBT immune reactions were classified according to time course as pre-engraftment immune reaction (PIR), engraftment syndrome (ES) or acute GVHD. Between March 2001 and November 2005, a total of 77 patients underwent CBT at eight transplantation centers. Median age was 48 years (range, 18-69 years). Preparative regimens comprised myeloablative (n=31) or reduced-intensity (n=46). Acute GVHD prophylaxis included cyclosporine alone (n=23), tacrolimus alone (n=12), cyclosporine plus MTX (n=17), tacrolimus plus short-term MTX (n=23) or cyclosporine plus methylprednisolone (n=2). Cumulative incidences of PIR, ES and grade II-IV GVHD were 36, 12 and 23%, respectively. Short-term MTX exerted significant favorable effects on post-CBT immune reactions (hazard ratio, 0.55; 95% confidence interval (95% CI), 0.31-0.98; P=0.04) in multivariate analysis. Overall survival rates for patients with and without short-term MTX at day 180 were 59% (95% CI, 42-73%) and 16% (95% CI, 6.6-30%) (P=0.0001), respectively. Short-term MTX could offer one optimal regimen to reduce immune reactions and improve outcomes in CBT.