MDS disease characteristics, not donor source, predict hematopoietic stem cell transplant outcomes.

Myelodysplastic syndrome (MDS) is a heterogeneous group of hematological malignancies with considerably variable prognoses and curable only with hematopoietic cell transplantation (HCT). Few studies comparing MDS HCT outcomes between sibling and umbilical cord blood (UCB) donors exist. Using the University of Minnesota Blood and Marrow Transplant (BMT) database, we retrospectively analyzed HCT outcomes among 89 MDS patients undergoing either sibling or double UCB HCT in 2000-2013. We observed similar survival, relapse and non-relapse mortality between sibling and UCB donor sources. Relapse was increased in those with monosomal karyotype (P=0.04) and with reduced intensity conditioning (P<0.01). In summary, our data highlight similar MDS HCT outcomes regardless of donor source and support the use of UCB as an alternative donor when a sibling is unavailable.

Lymphodepleting chemotherapy with donor lymphocyte infusion post-allogeneic HCT for hematological malignancies is associated with severe, but therapy-responsive aGvHD.

Donor lymphocyte infusion (DLI) is an option for relapsed hematologic malignancies or incomplete chimerism of non-malignant diseases following allogeneic hematopoietic cell transplantation (HCT). We analyzed the incidence of acute GvHD (aGvHD) in patients treated with DLI. From 1995 to 2013, 171 DLIs were given to 120 patients. The cumulative incidence of post-DLI grade II-IV aGvHD was 33% (CI 25-42%, n=40; 12 grade II), and of grade III-IV 24% (CI 16-32%, n=28). GvHD after DLI (n=46) involved the skin in 70% (n=32), lower gastrointestinal (GI) 65% (n=30), upper GI 43% (n=20) and liver 35% (n=16). Patients receiving chemotherapy accompanying the DLI (chemo-DLI) (n=37) had more frequent aGvHD and particularly lower GI GvHD. Risk factors for grade II-IV aGvHD included age >40, chemo-DLI, malignant disease and time from HCT to DLI <200 days. aGvHD response to treatment at 8 weeks was complete in 40% and complete/partial (CR/PR) in 52%. Chemo-DLI had higher response rates to aGVHD treatment in non-CML malignancies. We observed frequent, yet therapy-responsive aGvHD following DLI. GI GvHD in particular is a significant risk when giving chemotherapy prior to DLI. Improvements in DLI efficacy and GvHD management are still needed.

Novel disease burden assessment predicts allogeneic transplantation outcomes in myelodysplastic syndrome.

Among patients with myelodysplastic syndrome (MDS) undergoing hematopoietic cell transplantation (HCT), the impact of residual pretransplant cytogenetically abnormal cells on outcomes remains uncertain. We analyzed HCT outcomes by time of transplant disease variables, including (1) blast percentage, (2) percentage of cytogenetically abnormal cells and (3) Revised International Prognostic Scoring System (R-IPSS) cytogenetic classification. We included 82 MDS patients (median age 51 years (range 18-71)) transplanted between 1995 and 2013 with abnormal diagnostic cytogenetics. Patients with higher percentages of cytogenetically abnormal cells experienced inferior 5-year survival (37-76% abnormal cells: relative risk (RR) 2.9; 95% confidence interval (CI) 1.2-7.2; P=0.02; and 77-100% abnormal cells: RR 5.6; 95% CI 1.9-19.6; P<0.01). Patients with >10% blasts also had inferior 5-year survival (RR 2.9; 95% CI 1.1-7.2; P=0.02) versus patients with ⩽2% blasts. Even among patients with ⩽2% blasts, patients with 77-100% cytogenetically abnormal cells had poor survival (RR 4.4; 95% CI 1.1-18.3; P=0.04). Increased non-relapse mortality (NRM) was observed with both increasing blast percentages (P<0.01) and cytogenetically abnormal cells at transplant (P=0.01) in multivariate analysis. We observed no impact of disease burden characteristics on relapse outcomes due to high 1-year NRM. In conclusion, both blast percentage and percentage of cytogenetically abnormal cells reflect MDS disease burden and predict post-HCT outcomes.

Hemorrhagic cystitis after allogeneic hematopoietic cell transplantation: risk factors, graft source and survival.

Although hemorrhagic cystitis (HC) is a common complication of allogeneic hematopoietic cell transplantation (alloHCT), its risk factors and effects on survival are not well known. We evaluated HC in a large cohort (n=1321, 2003-2012) receiving alloHCT from all graft sources, including umbilical cord blood (UCB). We compared HC patients with non-HC (control) patients and examined clinical variables at HC onset and resolution. Of these 1321 patients, 219 (16.6%) developed HC at a median of 22 days after alloHCT. BK viruria was detected in 90% of 109 tested HC patients. Median duration of HC was 27 days. At the time of HC diagnosis, acute GVHD, fever, severe thrombocytopenia and steroid use were more frequent than at the time of HC resolution. In univariate analysis, male sex, age <20 years, myeloablative conditioning with cyclophosphamide and acute GVHD were associated with HC. In multivariate analysis, HC was significantly more common in males and HLA-mismatched UCB graft recipients. Severe grade HC (grade III-IV) was associated with increased treatment-related mortality but not with overall survival at 1 year. HC remains hazardous and therefore better prophylaxis, and early interventions to limit its severity are still needed.

The effect of equine antithymocyte globulin on the outcomes of reduced intensity conditioning for AML.

Whether or not the benefits of antithymocyte globulin (ATG) on engraftment and GVHD are offset by increased risk of relapse, delayed T-cell recovery and increased infections remains controversial. We retrospectively studied the effect of ATG in 144 AML patients, 34 of whom received ATG, undergoing reduced intensity conditioning (RIC) umbilical cord blood transplantation (UCB) or HLA-matched sibling PBSC. ATG patients had not received intensive chemotherapy for 3 months before transplantation for UCB, 6 months for PBSC. There were no differences in engraftment between ATG and non-ATG patients. The cumulative incidences of TRM as well as acute and chronic GVHD in ATG-treated patients were not statistically different. ATG patients had significantly more infections between 46 and 180 days post transplantation. Unexpectedly, after adjusting for donor type, relapse was lower among ATG recipients (relative risk (RR) 0.5, 95% confidence interval (CI) 0.3-1.0, P=0.04). In summary, administration of ATG to AML patients undergoing RIC had no adverse impact on major clinical outcomes. ATG may be indicated for patients at higher risk of graft failure after allogeneic hematopoietic cell transplantation (allo-HCT).

Clinical outcomes of AML patients relapsing after matched-related donor and umbilical cord blood transplantation.

AML relapse remains the leading cause of transplant failure among Allo-SCT recipients. A single institution study was conducted on 348 patients with AML who received an Allo-SCT from an umbilical cord blood (UCB, 222) or HLA-matched-related (RD, 126) donor between 2000-2011. Relapse after Allo-SCT occurred in 72 UCB and 32 RD transplant recipients. Three patients achieved CR after withdrawal of immune suppression with no further therapy. Fifty-two patients received intensive post-relapse therapy, defined as systemic chemotherapy (22 UCB, 7 RD), second Allo-SCT (nine UCB, two RD), or DLI±systemic chemotherapy (0 UCB, 12 RD); of these, 25% achieved CR (21% UCB vs 35% RD, P=0.16). Survival at 1 year after relapse was 22% for all patients (19% UCB vs 28% RD, P=0.36). In multivariable analysis, post-relapse mortality was lower in patients receiving intensive therapy for relapse (hazard ratio (HR)=0.4; 95% confidence interval (CI) 0.2-0.6, P<0.01) and higher in patients with peripheral blood blasts above the median (HR=3.8; 95% CI 2.2-6.6, P<0.01), active infection (HR=1.9; 95% CI 1.0-3.5, P=0.05) and non-infectious medical complications (HR=2.0; 95% CI 1.2-3.5, P=0.01). In conclusion, patients with AML relapsing after Allo-SCT who were in good-enough clinical condition to receive intensive therapy had superior short-term survival.

Higher therapeutic CsA levels early post transplantation reduce risk of acute GVHD and improves survival.

We studied whether early CsA trough levels were associated with the risk of acute GVHD in 337 patients after either sibling PBSC or double umbilical cord blood transplantation. All patients, regardless of donor type, started CsA at a dose of 5 mg/kg i.v. divided twice daily, targeting trough concentrations 200-400 ng/mL. The CsA level was studied by a weighted average method calculated by giving 70% of the weight to the level that was measured just before the onset of the event or day +30. We found that higher weighted average CsA trough levels early post transplantation contributed to lower risk of acute GVHD, and lower non-relapse and overall mortality. Thus, our data support close monitoring with active adjustments of CsA dosing to maintain therapeutic CsA levels in the first weeks of allo-HCT. In patients who are near or even modestly above the CsA target trough level, in the absence of CsA-related toxicity, dose reduction should be cautious to avoid subtherapeutic drug levels resulting in higher risk of acute GVHD.

Similar outcomes between adolescent/young adults and children with AML following allogeneic hematopoietic cell transplantation.

We recently reported that adolescents and young adults (AYAs) with B-cell ALL receiving allogeneic hematopoietic cell transplantation (allo-HCT) have inferior survival compared with children, primarily because of greater TRM. We therefore hypothesized that in the setting of allo-HCT for AML, similar inferior outcomes would be observed in AYA patients as compared with children. We reviewed outcomes of 168 consecutive patients (ages 0-30 years) with AML undergoing allo-HCT at our institution. Of these, 60% (n=101) were <15 years of age and 40% (n=67) were AYAs (15-30 years of age). We identified no significant differences in 5-year overall survival (48% vs 50%, P=0.89), disease-free (47% vs 47%, P=0.89), relapse (24% vs 33%, P=0.30) or TRM (27% vs 16%, P=0.10) between the two groups. However, AYA patients had a greater incidence of grade II-IV acute (48% vs 31%, P=0.01) and chronic GVHD (22% vs 7%, P<0.01). Based on this analysis we identified no differences in survival, relapse or TRM between AYAs and children with AML receiving allo-HCT.

Achieving stringent CR is essential before reduced-intensity conditioning allogeneic hematopoietic cell transplantation in AML.

Reduced-intensity conditioning (RIC) allogeneic hematopoietic cell transplantation (allo-HCT) can cure patients with AML in CR. However, relapse after RIC allo-HCT may indicate heterogeneity in the stringency of CR. Strict definition of CR requires no evidence of leukemia by both morphologic and flow cytometric criteria. We re-evaluated 85 AML patients receiving RIC allo-HCT in CR to test if a strict definition of CR had direct implications for the outcome. These patients had leukemia immunophenotype documented at diagnosis and analyzed at allo-HCT. Eight (9.4%) had persistent leukemia by flow cytometric criteria at allo-HCT. The patients with immunophenotypic persistent leukemia had a significantly increased relapse (hazard ratio (HR): 3.7; 95% confidence interval (CI): 1.3-10.3, P=0.01) and decreased survival (HR: 2.9; 95% CI: 1.3-6.4, P<0.01) versus 77 patients in CR by both morphology and flow cytometry. However, the pre-allo-HCT bone marrow (BM) blast count (that is, 0-4%) was not significantly associated with risks of relapse or survival. These data indicate the presence of leukemic cells, but not the BM blast count affects survival. A strict morphologic and clinical lab flow cytometric definition of CR predicts outcomes after RIC allo-HCT, and therefore is critical to achieve at transplantation.

Reduced-intensity hematopoietic cell transplantation in older patients with AML/MDS: umbilical cord blood is a feasible option for patients without HLA-matched sibling donors.

Umbilical cord blood (UCB) has increased access to hematopoietic cell transplantation (HCT) for patients without HLA-matched sibling donors (MSD). We compared outcomes of HCT using MSD (N=38) or UCB (N=60) among older patients (age ≥ 55 years) with AML or myelodysplastic syndromes (MDS). All patients received a reduced intensity regimen consisting of CY, fludarabine and 200 cGy TBI. Median age at HCT was 63 years for MSD and 61 years for UCB recipients. Among UCB recipients, 95% received two UCB units and 88% received 1-2 locus HLA-mismatched units to optimize cell dose. OS at 3-years was 37% for MSD and 31% for UCB recipients (P=0.21). On multivariate analysis, donor source (MSD vs UCB) did not impact risks of OS, leukemia-free survival and relapse or treatment-related mortality. UCB is feasible as an alternative donor source for reduced-intensity conditioning HCT among older patients with AML and MDS who do not have a suitable MSD.

Myelodysplastic syndromes: review of pathophysiology and current novel treatment approaches.

Myelodysplastic syndromes (MDS) are a heterogeneous group of clonal disorders of hematopoietic progenitors manifest by cytopenias, bleeding, infection, and potential for progression to acute myelogenous leukemia. The wide spectrum of clinical manifestations, including variability in illness severity and potential for progression, suggest that myelodysplastic syndromes encompass a multitude of disorders, likely involving numerous pathologic pathways. In fact, it is the effort to understand the underlying biology of these syndromes that has led to recent advances in treatment approaches, including the FDA approval of three new agents (5-azacitidine, decitabine, and lenalidomide) for the treatment of MDS. This review will present data supporting each of the current pathophysiologic pathways implicated in the development and progression of MDS; summarize the emerging clinical paradigms for treating patients with MDS; and offer insights into several novel approaches attempting to improve treatment options for future MDS patients.