Hamadani, Mehdi

Abstract The optimal source of donor hematopoietic stem cells (HSC) is controversial. Granulocyte colony stimulating factor (G-CSF) mobilized peripheral blood (G-PB) has replaced bone marrow (BM) as the most common allograft source in adults but is associated with donor morbidity and higher rates of chronic graft versus host disease (GVHD) compared to BM. The CXCR4 antagonist plerixafor (Px) mobilizes HSC into the PB (Px-PB) faster than G-CSF and preliminary data suggest both quantitative and qualitative differences in allograft content that may impact clinical outcomes. We sought to assess the efficacy and safety of transplanted allografts collected following mobilization with Px alone in HLA-identical sibling transplantation. This was a Phase II, two-strata, multi-center prospective trial (NCT01696461) to evaluate Px-PB allografts prior to reduced intensity conditioning (RIC) and myeloablative conditioning (MAC) based hematopoietic cell transplantation (HCT). Patients aged 18-65 years with an HLA-ID sibling donor and a hematological malignancy suitable for HCT were eligible. The primary objective was to determine the proportion of donors whose cells could be successfully mobilized and collected with a sufficient CD34+ cell dose using Px as the sole mobilizing agent. Px mobilization was considered successful if ≥ 2.0x10^6 CD34+ cells/kg recipient weight were collected in no more than two leukapheresis (LP) collections. All donors receiving Px were included in the analysis of the primary objective based on the intention-to-treat principle. Secondary objectives included the incidence of acute and chronic adverse events in donors, rates of hematopoietic engraftment, donor chimerism, rates of acute and chronic GVHD, non-relapse mortality (NRM), progression free survival (PFS) and overall survival (OS) for the recipients. From July 2013 to December 2014, 64 donor/recipient pairs were enrolled at 12 centers. Donors received Px at 240μg/kg subcutaneously 4 hours prior to LP. LP was performed processing at least 4X blood volume for up to two consecutive days (a third day was allowed for low CD34+ cell yields after 2 LP procedures) to achieve a target CD34+ cell dose of ≥ 4.0 x 10^6/kg recipient weight with a minimum goal of ≥ 2.0 x 10^6/kg. All allografts were cryopreserved. GVHD prophylaxis included cyclosporine or tacrolimus in combination with methotrexate, mycophenolate mofetil, or sirolimus. G-CSF was given routinely post HCT only to MAC recipients. Patient demographics are provided in Table 1. The median donor age was 56 years (18-65). 64% of the donors were male. Donors underwent one (23%), two (72%), or three (5%) LP procedures. 63 of 64 (98%) donors achieved the primary objective. The median total CD34+ cell dose/kg recipient weight collected within 2 days was 4.6 (0.9-9.6). Maximal donor toxicity following Px injection and LP was grades 0 (30%), 1 (52%), 2 (17%), and 3 (2%). Bloating, flatulence, abdominal pain, headache, paresthesisas, injection site reaction, and dizziness were the most commonly observed toxicities. Bone pain was not observed. The one grade 3 toxicity was a vasovagal episode felt related to LP and unlikely to Px. Toxicities typically resolved within a week of LP. The median follow up is 6.3 months. Median days to ANC (>0.5 x10^9/L) and Platelet count (>20 x 10^9/L) recovery were 13.5 (10-148) and 19 (1-76) after MAC and 14.5 (0-25) and 18 (0-141) after RIC, respectively. The cumulative incidence of acute GVHD grades 2-4 and 3-4 at day 100 were 47% (95% CI: 30-64) and 9% (95% CI: 2-22) after MAC and 19% (95% CI: 6-38) and 5% (95% CI: 0-18) after RIC. Probability of NRM at day 100 was 4% (95% CI: 0-13) and 0% after MAC and RIC, respectively. The probability of OS at day 100 was 97% (95% CI: 88-100) and 90% (95% CI: 78-98) after MAC and RIC, respectively. In conclusion, this is the first multi-center trial to demonstrate that as an alternative to G-CSF, Plerixafor rapidly, safely, and effectively mobilizes sufficient numbers of CD34+ cells from HLA-ID sibling donors for HCT following both RIC and MAC regimens. Engraftment was generally prompt and early results of secondary endpoints in recipients are encouraging. Longer follow-up and more extensive analysis of donor allografts and recipient outcomes will be presented at the time of the meeting. Research support was provided in part by Genzyme, a Sanofi Company. Table 1. Characteristics of recipients Table 1. Characteristics of recipients Disclosures Chen: Bayer: Consultancy, Research Funding. Devine:Genzyme: Research Funding.

BackgroundThe outcomes for patients with diffuse large B‐cell lymphoma (DLBCL) with adverse clinical prognostic factors such as a high age‐adjusted International Prognostic Index (aaIPI) are not optimal. In the current study, the authors performed a systematic review and meta‐analysis to assess the totality of evidence pertaining to the efficacy of autologous hematopoietic stem cell transplantation (auto‐HCT) consolidation for patients with DLBCL in first remission.MethodsThe authors searched the Cochrane and MEDLINE/PubMed databases through December 1, 2018, for studies comparing conventional chemotherapy with rituximab (R‐chemo) versus R‐chemo and auto‐HCT. Two authors independently reviewed all references for study inclusion and extracted data related to benefits (overall survival, progression‐free survival, and response rates) and harms (treatment‐related mortality and adverse events).ResultsFour studies (1173 patients) met the inclusion criteria and were included in the current analysis. The median duration of follow‐up ranged from 42 to 76 months. There was no difference noted with regard to the overall survival (hazard ratio, 1.01; 95% CI, 0.74‐1.37), progression‐free survival (hazard ratio, 0.77; 95% CI, 0.58‐1.04), or response rates (risk ratio, 0.98; 95% CI, 0.92‐1.04) between patients who received R‐chemo and auto‐HCT and those who received R‐chemo alone. The risk of mortality and therapy failure was not found to be different when the analysis was limited to high aaIPI between the 2 groups. Although there was no difference noted with regard to the risk of treatment‐related mortality, there was a significantly higher incidence of CTCAE grade 3 or 4 adverse events in patients who received R‐chemo and auto‐HCT compared with patients treated with R‐chemo alone.ConclusionsThe findings from what to the authors' knowledge is the first meta‐analysis performed in the rituximab era demonstrated no beneficial effect of upfront auto‐HCT consolidation in patients with aggressive B‐cell non‐Hodgkin lymphoma, including high‐risk clinical groups (high aaIPI).

Abstract Purpose: To develop a prognostic model and cytogenetic risk classification for previously treated patients with chronic lymphocytic leukemia (CLL) undergoing reduced intensity conditioning (RIC) allogeneic hematopoietic cell transplantation (HCT). Experimental Design: We performed a retrospective analysis of outcomes of 606 patients with CLL who underwent RIC allogeneic HCT between 2008 and 2014 reported to the Center for International Blood and Marrow Transplant Research. Results: On the basis of multivariable models, disease status, comorbidity index, lymphocyte count, and white blood cell count at HCT were selected for the development of prognostic model. Using the prognostic score, we stratified patients into low-, intermediate-, high-, and very-high-risk [4-year progression-free survival (PFS) 58%, 42%, 33%, and 25%, respectively, P < 0.0001; 4-year overall survival (OS) 70%, 57%, 54%, and 38%, respectively, P < 0.0001]. We also evaluated karyotypic abnormalities together with del(17p) and found that del(17p) or ≥5 abnormalities showed inferior PFS. Using a multivariable model, we classified cytogenetic risk into low, intermediate, and high (P < 0.0001). When the prognostic score and cytogenetic risk were combined, patients with low prognostic score and low cytogenetic risk had prolonged PFS (61% at 4 years) and OS (75% at 4 years). Conclusions: In this large cohort of patients with previously treated CLL who underwent RIC HCT, we developed a robust prognostic scoring system of HCT outcomes and a novel cytogenetic-based risk stratification system. These prognostic models can be used for counseling patients, comparing data across studies, and providing a benchmark for future interventions. For future study, we will further validate these models for patients receiving targeted therapies prior to HCT.

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 < .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.

BACKGROUNDEarly treatment failure (ETF) in follicular lymphoma (FL), defined as relapse or progression within 2 years of frontline chemoimmunotherapy, is a newly recognized marker of poor survival and identifies a high‐risk group of patients with an expected 5‐year overall survival (OS) rate of approximately 50%. Transplantation is an established option for relapsed FL, but its efficacy in this specific ETF FL population has not been previously evaluated.METHODSThis study compared autologous hematopoietic stem cell transplantation (auto‐HCT) with either matched sibling donor (MSD) or matched unrelated donor (MUD) allogeneic hematopoietic cell transplantation (allo‐HCT) as the first transplantation approach for patients with ETF FL (age ≥ 18 years) undergoing auto‐HCT or allo‐HCT between 2002 and 2014. The primary endpoint was OS. The secondary endpoints were progression‐free survival, relapse, and nonrelapse mortality (NRM).RESULTSFour hundred forty FL patients had ETF (auto‐HCT, 240; MSD hematopoietic stem cell transplantation [HCT], 105; and MUD HCT, 95). With a median follow‐up of 69 to 73 months, the adjusted probability of 5‐year OS was significantly higher after auto‐HCT (70%) or MSD HCT (73%) versus MUD HCT (49%; P = .0008). The 5‐year adjusted probability of NRM was significantly lower for auto‐HCT (5%) versus MSD (17%) or MUD HCT (33%; P < .0001). The 5‐year adjusted probability of disease relapse was lower with MSD (31%) or MUD HCT (23%) versus auto‐HCT (58%; P < .0001).CONCLUSIONSPatients with high‐risk FL, as defined by ETF, undergoing auto‐HCT for FL have low NRM and a promising 5‐year OS rate (70%). MSD HCT has lower relapse rates than auto‐HCT but similar OS. Cancer 2018;124:2541‐51. © 2018 American Cancer Society.

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.

Summary For diffuse large B‐cell lymphoma ( DLBCL ) patients progressing after autologous haematopoietic cell transplantation (auto HCT ), allogeneic HCT (allo HCT ) is often considered, although limited information is available to guide patient selection. Using the Center for International Blood and Marrow Transplant Research ( CIBMTR ) database, we identified 503 patients who underwent allo HCT after disease progression/relapse following a prior auto HCT . The 3‐year probabilities of non‐relapse mortality, progression/relapse, progression‐free survival ( PFS ) and overall survival ( OS ) were 30, 38, 31 and 37% respectively. Factors associated with inferior PFS on multivariate analysis included Karnofsky performance status ( KPS ) <80, chemoresistance, auto HCT to allo HCT interval <1‐year and myeloablative conditioning. Factors associated with worse OS on multivariate analysis included KPS <80, chemoresistance and myeloablative conditioning. Three adverse prognostic factors were used to construct a prognostic model for PFS , including KPS <80 (4 points), auto HCT to allo HCT interval <1‐year (2 points) and chemoresistant disease at allo HCT (5 points). This CIBMTR prognostic model classified patients into four groups: low‐risk (0 points), intermediate‐risk (2‐5 points), high‐risk (6‐9 points) or very high‐risk (11 points), predicting 3‐year PFS of 40, 32, 11 and 6%, respectively, with 3‐year OS probabilities of 43, 39, 19 and 11% respectively. In conclusion, the CIBMTR prognostic model identifies a subgroup of DLBCL patients experiencing long‐term survival with allo HCT after a failed prior auto HCT .