Waller, Edmund K.

Abstract Abstract 739 The combination of a calcineurin inhibitor and methotrexate has been the standard of care in graft-vs.-host disease (GVHD) prophylaxis for over 25 years, with resultant rates of grade II-IV acute GVHD between 30–50%. The mTOR inhibitor, sirolimus, has demonstrated promise in a number of Phase II trials as an immunosuppressant used for GVHD prophylaxis. The BMT CTN, sponsored by the NHLBI and NCI, conducted a multicenter, randomized controlled trial comparing the combination of tacrolimus and sirolimus (Tac/Sir) with tacrolimus and methotrexate (Tac/Mtx) as GVHD prophylaxis after matched, related donor (MRD) hematopoietic stem cell transplantation (HSCT). Methods: Eligible patients were between ages 2 – 60 years, and had acute leukemia in remission, myelodysplasia or chronic myeloid leukemia in chronic or accelerated phase. All had adequate organ function, and a 6/6 HLA-A, B, DRB1 matched sibling donor. 304 patients were randomly assigned to either Tac/Sir (n = 151) or Tac/Mtx (n = 153) as GVHD prophylaxis after TBI-based conditioning and MRD HSCT. An intent-to-treat analysis was performed on the primary endpoint of Grade II-IV GVHD-free survival 114 days from randomization. Ten subjects who received busulfan-based conditioning and were previously reported were excluded from analysis. Three subjects who did not undergo HSCT are included in the primary analysis, but not secondary analyses. Results: Treatment groups were well balanced. The median age of participants was 44 years (range 13 – 59) and 83% had acute leukemia. Neutrophil and platelet engraftment were both faster in the Tac/Sir group (14 vs. 16 days, p < 0.001; 16 vs. 19 days, p = 0.03, respectively), but this did not affect the time to first hospital discharge (20 vs. 21 days, p = 0.37). The incidence of grade II-IV and grade III-IV acute GVHD at 100 days were lower in the Tac/Sir group (26 vs. 34%, p = 0.17; 8 vs. 15%, p = 0.05). Day 100 treatment-related mortality was no different between groups (7 vs. 7%, p = 0.43). The primary endpoint of 114-day acute GVHD-free survival was not statistically different between groups (67 vs. 62%, p = 0.38, Figure). The cumulative incidence of relapse at 2 years from transplantation was not different between groups (27 vs. 30%, p = 0.81). The competing-risk cumulative incidence of chronic GVHD was higher in the Tac/Sir arm (54 vs. 43%, p =0.044). Overall toxicities were not different between groups, with two notable exceptions. The peak and average OMAS oral mucositis scores were lower in the Tac/Sir arm (peak 0.70 vs. 0.96, p < 0.001; average 0.31 vs. 0.47, p < 0.001), however, there was an increased rate of the endothelial injury syndromes, veno-occlusive disease (11 vs. 4%, p = 0.03), and thrombotic microangiopathy (5 vs. 1%, p = 0.05) in the Tac/Sir arm. Causes of death were not different between groups. At 2 years from transplantation, disease-free (DFS) and overall survival (OS) were not different between study arms (DFS 53 vs. 53%, p = 0.76; OS 60 vs. 61%, p = 0.44). Conclusions: No difference in 114-day acute GVHD-free survival was noted between treatment arms. Compared with Tac/Mtx in MRD HSCT, Tac/Sir is associated with more rapid engraftment, less severe acute GVHD and oral mucositis, excess chronic GVHD and endothelial injury syndromes, and similar long-term outcomes. Understanding the trade-offs between regimens, Tac/Sir can be used as an alternative to Tac/Mtx in MRD HSCT. Disclosures: Cutler: Pfizer, inc: Research Funding; Astellas, Inc: Consultancy, Research Funding. Off Label Use: Sirolimus - Prevention of GVHD Tacrolimus - Prevention of GVHD. Waller:Outsuka: Research Funding.

Abstract HLA-haploidentical hematopoietic cell transplantation (Haplo-HCT) using posttransplantation cyclophosphamide (PT-Cy) has improved donor availability. However, a matched sibling donor (MSD) is still considered the optimal donor. Using the Center for International Blood and Marrow Transplant Research database, we compared outcomes after Haplo-HCT vs MSD in patients with acute myeloid leukemia (AML) in first complete remission (CR1). Data from 1205 adult CR1 AML patients (2008-2015) were analyzed. A total of 336 patients underwent PT-Cy–based Haplo-HCT and 869 underwent MSD using calcineurin inhibitor–based graft-versus-host disease (GVHD) prophylaxis. The Haplo-HCT group included more reduced-intensity conditioning (65% vs 30%) and bone marrow grafts (62% vs 7%), consistent with current practice. In multivariable analysis, Haplo-HCT and MSD groups were not different with regard to overall survival (P = .15), leukemia-free survival (P = .50), nonrelapse mortality (P = .16), relapse (P = .90), or grade II-IV acute GVHD (P = .98). However, the Haplo-HCT group had a significantly lower rate of chronic GVHD (hazard ratio, 0.38; 95% confidence interval, 0.30-0.48; P &lt; .001). Results of subgroup analyses by conditioning intensity and graft source suggested that the reduced incidence of chronic GVHD in Haplo-HCT is not limited to a specific graft source or conditioning intensity. Center effect and minimal residual disease–donor type interaction were not predictors of outcome. Our results indicate a lower rate of chronic GVHD after PT-Cy–based Haplo-HCT vs MSD using calcineurin inhibitor–based GVHD prophylaxis, but similar other outcomes, in patients with AML in CR1. Haplo-HCT is a viable alternative to MSD in these patients.

Abstract Plerixafor, a direct antagonist of CXCR4/stromal-derived factor 1, can safely and rapidly mobilize allografts without the use of granulocyte colony-stimulating factor (G-CSF). We conducted a phase 2, multicenter, prospective study of plerixafor-mobilized HLA-identical sibling allografts for allogeneic hematopoietic cell transplantation in recipients with hematological malignancies. Donors (n = 64) were treated with subcutaneous plerixafor (240 µg/kg) and started leukapheresis (LP) 4 hours later. The primary objective was to determine the proportion of donors who were successfully mobilized: defined as collection of ≥2.0 × 106 CD34+ cells per kilogram recipient weight in ≤2 LP sessions. Recipients subsequently received reduced intensity (RIC; n = 33) or myeloablative (MAC; n = 30) conditioning. Sixty-three of 64 (98%) donors achieved the primary objective. The median CD34+ cell dose per kilogram recipient weight collected within 2 days was 4.7 (0.9-9.6). Plerixafor was well tolerated with only grade 1 or 2 drug-related adverse events noted. Bone pain was not observed. Plerixafor-mobilized grafts engrafted promptly. One-year progression-free and overall survivals were 53% (95% confidence interval [CI], 36% to 71%) and 63% (95% CI, 46% to 79%) for MAC and 64% (95% CI, 47% to 79%) and 70% (95% CI, 53% to 84%) for RIC recipients, respectively. Donor toxicity was reduced relative to G-CSF mobilized related donors. This is the first multicenter trial to demonstrate that, as an alternative to G-CSF, plerixafor rapidly and safely mobilizes sufficient numbers of CD34+ cells from matched sibling donors for HCT. Engraftment was prompt, and outcomes in recipients were encouraging. This trial was registered at clinicaltrials.gov as #NCT01696461.

Key Points There was no difference in overall survival after allogeneic transplant between patients aged 55-64 years and patients ≥65 years. Age alone should not be a determinant for allogeneic transplant eligibility among older non-Hodgkin lymphoma patients.

BACKGROUNDPatients with FMS like tyrosine kinase 3 (FLT3)‐mutated acute myeloid leukemia (AML) have a poor prognosis and are referred for early allogeneic hematopoietic stem cell transplantation (HCT).METHODSData from the Center for International Blood and Marrow Transplant Research (CIBMTR) were used to evaluate 511 adult patients with de novo AML who underwent HCT during 2008 through 2011 to determine whether FLT3 mutations had an impact on HCT outcomes.RESULTSIn total, 158 patients (31%) had FLT3 mutations. Univariate and multivariate analyses revealed an increased risk of relapse at 3 years in the FLT3 mutated group compared with the wild‐type (WT) group (38% [95% confidence interval (CI), 30%‐45%] vs 28% [95% CI, 24%‐33%]; P = .04; relative risk, 1.60 [95% CI, 1.15‐2.22]; P = .0048). However, FLT3 mutation status was not significantly associated with nonrelapse mortality, leukemia‐free survival, or overall survival. Although more patients in the FLT3 mutated group died from relapsed primary disease compared with those in the WT group (60% vs 46%), the 3‐year overall survival rate was comparable for the 2 groups (mutated group: 49%; 95% CI, 40%‐57%; WT group: 55%, 95% CI, 50%‐60%; P = .20).CONCLUSIONSThe current data indicate that FLT3 mutation status did not adversely impact overall survival after HCT, and about 50% of patients with this mutation who underwent HCT were long‐term survivors. Cancer 2016;122:3005‐3014. © 2016 American Cancer Society.

Key Points Tac/Sir prophylaxis provides equivalent GVHD-free survival when compared with Tac/Mtx in MRD transplantation. Tac/Sir is associated with more rapid engraftment and reduced oropharyngeal mucositis after MRD transplantation.

PurposeTo examine the outcomes of patients with chemotherapy-sensitive mantle-cell lymphoma (MCL) following a first hematopoietic stem-cell transplantation (HCT), comparing outcomes with autologous (auto) versus reduced-intensity conditioning allogeneic (RIC allo) HCT and with transplantation applied at different times in the disease course.Patients and MethodsIn all, 519 patients who received transplantations between 1996 and 2007 and were reported to the Center for International Blood and Marrow Transplant Research were analyzed. The early transplantation cohort was defined as those patients in first partial or complete remission with no more than two lines of chemotherapy. The late transplantation cohort was defined as all the remaining patients.ResultsAuto-HCT and RIC allo-HCT resulted in similar overall survival from transplantation for both the early (at 5 years: 61% auto-HCT v 62% RIC allo-HCT; P = .951) and late cohorts (at 5 years: 44% auto-HCT v 31% RIC allo-HCT; P = .202). In both early and late transplantation cohorts, progression/relapse was lower and nonrelapse mortality was higher in the allo-HCT group. Overall survival and progression-free survival were highest in patients who underwent auto-HCT in first complete response. Multivariate analysis of survival from diagnosis identified a survival benefit favoring early HCT for both auto-HCT and RIC allo-HCT.ConclusionFor patients with chemotherapy-sensitive MCL, the optimal timing for HCT is early in the disease course. Outcomes are particularly favorable for patients undergoing auto-HCT in first complete remission. For those unable to achieve complete remission after two lines of chemotherapy or those with relapsed disease, either auto-HCT or RIC allo-HCT may be effective, although the chance for long-term remission and survival is lower.

Key Points In combination with cyclophosphamide, intravenous busulfan is associated with better leukemia-free and overall survival in AML than TBI.

SummaryPre‐existing central nervous system (CNS) involvement may influence referral for autologous haematopoietic cell transplantation (AHCT) for patients with non‐Hodgkin lymphoma (NHL). The outcomes of 151 adult patients with NHL with prior secondary CNS involvement (CNS+) receiving an AHCT were compared to 4688 patients without prior CNS lymphoma (CNS−). There were significant baseline differences between the cohorts. CNS+ patients were more likely to be younger, have lower performance scores, higher age‐adjusted international prognostic index scores, more advanced disease stage at diagnosis, more aggressive histology, more sites of extranodal disease, and a shorter interval between diagnosis and AHCT. However, no statistically significant differences were identified between the two groups by analysis of progression‐free survival (PFS) and overall survival (OS) at 5 years. A matched pair comparison of the CNS+ group with a subset of CNS− patients matched on propensity score also showed no differences in outcomes. Patients with active CNS lymphoma at the time of AHCT (n = 55) had a higher relapse rate and diminished PFS and OS compared with patients whose CNS lymphoma was in remission (n = 96) at the time of AHCT. CNS+ patients can achieve excellent long‐term outcomes with AHCT. Active CNS lymphoma at transplant confers a worse prognosis.