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A second intensification is an option at first relapse in multiple myeloma (MM) after more than 36 months of initial remission. Many conditioning regimens have been tested, with or without total body irradiation (TBI). Recently, it was found that TBI could be replaced by total marrow irradiation (TMI) using helical tomotherapy, with promising results.This study was a prospective multicenter phase 1 trial that aimed to determine the maximum tolerated dose (MTD) of TMI administered in association with melphalan 140 mg/m², followed by autologous stem cell transplantation as consolidation at first relapse in MM. Four dose levels were explored: 8 Gy, 10 Gy, 12 Gy, and 14 Gy. The dose-limiting toxicity (DLT) was defined as grade 4 neutropenia15 days, grade 4 thrombopenia28 days, and all other grade 4 nonhematologic toxic effects except nausea, vomiting, alopecia, mucositis, and reaction to autologous stem cell infusion.Thirteen patients were included; only 1 DLT at the third escalated dose level (12 Gy) was observed, whereas 1 patient was treated at 14 Gy with no adverse events. The MTD was not reached. The rate of acute toxicity was low: 38% of grade 3-4 diarrhea, mucositis, or unexplained fever. Regarding the lungs, the mean dose administered was systematically less than 8 Gy. After a median follow-up of 55 months, 70% of participants were alive. Of these 13 patients, 38.5% were in very good partial response and 30.8% were in complete response. Three of them were progression-free. Six patients were long survivors, still alive after 55 months of follow-up.Total marrow irradiation provides good results with a good tolerance profile at first relapse in MM and makes it possible to increase the dose delivered to the planning target volume while sparing organs at risk. This technique could be discussed for all regimens before auto- or allo-stem cell rescue when TBI is required.

Androgens have represented the historical therapeutic backbone of bone marrow failure (BMF) syndromes. However, their role has been rarely analyzed in prospective setting and systematic and long-term data are currently unavailable regarding their usage, effectiveness and toxicity in both acquired and inherited BMF. Here, taking advantage of a unique disease-specific international dataset, we retrospectively analyzed the so far largest cohort of BMF patients who received androgens before or in absence of an allogeneic hematopoietic cell transplantation (HCT), reappraising their current use in these disorders. We identified 274 patients across 82 EBMT affiliated centers, 193 with acquired (median age of 32) and 81 with inherited BMF (median age of 8 years). With a median duration of androgen treatment of 5.6 and 20 months respectively, complete/partial remission rates at 3 months were of 6%/29% in acquired and 8%/29% in inherited disorders. Five-year overall survival and failure free survival (FFS) were respectively 63% and 23% in acquired and 78% and 14% in inherited contexts. Androgen initiation after second line treatments for acquired, and after > 12 months post-diagnosis for inherited group were identified as factors associated with improved FFS in multivariable analysis. Androgen use was associated with a manageable incidence of organ-specific toxicity and low rates of solid and hematological malignancies. Sub-analysis of transplant-related outcomes after exposure to these compounds showed probabilities of survival and complications similar to other transplanted BMF cohorts. This study delivers a unique opportunity to track androgen use in BMF syndromes and represents the basis for general recommendations on their use on behalf of the SAAWP of the EBMT.

Second- and third-generation tyrosine kinase inhibitors (TKI) play an important role in the treatment of Philadelphia chromosome-positive acute lymphoblastic leukemia (Ph + ALL). However, data on feasibility and efficacy of using these drugs for persisting or relapsed Ph + ALL after allogeneic stem cell transplantation (alloSCT) are scarce. Based on the EBMT Acute Leukemia Working Party registry, we evaluated the use of second-/third-generation TKI in 140 patients with Ph + ALL, suffering from measurable residual disease (MRD, n = 6), molecular relapse (MRel, n = 23), or hematological relapse (HRel, n = 111) following alloSCT. Treatment included dasatinib in 104, nilotinib in 18, or ponatinib in 18 patients. Forty-nine patients received TKI monotherapy, while 91 received additional treatment. Toxicity of second-/third-generation TKI post alloSCT was comparable to pretransplant use and could be managed with dose reduction or temporary discontinuation. Response rates were 71% (overall) and 61% (following TKI monotherapy). For the entire cohort, 2- and 5-year overall survival (OS) was 49% and 33%, respectively. OS was comparable among patients treated for persisting MRD/MRel and HRel. Among patients treated with TKI monotherapy, 2- and 5-year OS was 38% and 33%, respectively. The data underscore that second-/third-generation TKI are important compounds for the management of active Ph + ALL post alloSCT.

Item does not contain fulltext We assessed the incidence and outcome of early candidemia after hematopoietic stem cell transplant (HSCT). The analysis included all first HSCTs performed from 2000 to 2015 in adult and pediatric patients with a non-leukemic disease and recorded in the EBMT registry. Overall survival (OS), non-relapse mortality (NRM), and relapse mortality (RM) were evaluated. Candidemia was diagnosed in 420 of 49,852 patients at a median time of 17 days post HSCT (range 0-100), the cumulative incidence being 0.85%. In 65.5% of episodes, candidemia occurred by day 30 after HSCT. The mortality rate by day 7 was 6.2%, whereas 100-day NRM was higher (HR 3.47, p

Medication non-adherence (NA) after allogeneic hematopoietic cell transplantation (allo-HCT) can lead to serious complications. This study assesses NA in French adult and pediatric recipients and identifies factors associated with NA. In accordance with the EMERGE and STROBE guidelines, a cross sectional multicentric survey was conducted. We used a self-reported questionnaire that was adapted to adults and pediatrics and that could provide a picture of all three phases of medication adherence: initiation, implementation, persistence. We enrolled 242 patients, 203 adults (mean age: 51 years old, 50.7% male) and 39 children (mean age: 9 years old, 56.4% female). Reported NA was estimated at about 75% in both populations, adults and pediatrics. In adults, the univariate analysis showed that patients less than 50 years old (P = 0.041), (i) treated with cyclosporine (P = 0.02), (ii) treated with valacyclovir/acyclovir (P = 0.016), and (iii) experiencing side effects (P = 0.009), were significantly more non-adherent. In multivariate analysis, only recipient age was significantly associated to NA (P = 0.05). The limited size of the pediatric population did not allow us to draw any statistical conclusion about this population. To the best of our knowledge, this is the first study in France on NA in allo-HCT recipients. Our results highlight the age factor as the only factor related to NA. Further studies are needed to confirm our observations and refine results in pediatric populations, currently most at risk of medication NA.

Letermovir (LMV) is licensed for prophylaxis of CMV infection in allogeneic hematopoietic cell transplant adult CMV-seropositive patients. Due to its favorable safety profile, LMV brings potential for use in other clinical situations, outside the approved indication. The objective of the study was to analyze the efficacy and safety of the use of LMV in off-label indications in EBMT centers. A total of 49 patients were reported including 44 adults and 5 children. LMV was administered for: secondary prophylaxis (37 adults, 3 children), primary prophylaxis (2 children), pre-emptive treatment (5 adults), and therapy of CMV disease (2 adults; pneumonia, colitis). Cyclosporine was concomitantly used in 26 patients. Overall, LMV was used for a median 112 days (range: 10-473). Cumulative incidence of breakthrough infections during secondary prophylaxis was 10.1% (95% CI=3.1-21.9). Prophylactic treatment with LMV resulted in 94.9% (95% CI=81.0-98.7), and 81.9% (95% CI=65.7-90.9) probability of, respectively, 60 and 120-day survival without CMV infection in patients receiving secondary prophylaxis. During therapy of CMV infection/disease, probability of 60 and 120-day overall survival was 100% and 71.4% (95% CI=25.8-92.0), respectively. No breakthrough infection occurred in children on LMV prophylaxis. Adverse events were reported in 15/49 (30.4%) patients: the most common being nausea/vomiting (22.4%). In conclusion, the efficacy of the use of LMV as secondary prophylaxis was high, and the preliminary experience with the use of LMV for the treatment of patients with refractory CMV infection/disease was positive. Our data showed that higher dose or prolonged therapy did not result in increased rate of adverse events.

Recently a new three-group clinical classification was reported by an International Consortium to stratify CMML patients with regard to prognosis. The groups were defined as follows: (1) Myelodysplastic (MD)-CMML: WBC ≤ 10 × 109/l, circulating immature myeloid cells (IMC) = 0, no splenomegaly; (2) MD/MP (overlap)–CMML: WBC 10–20 × 109/l or WBC ≤ 10 × 109/l but IMC > 0 and/or splenomegaly; (3) Myeloproliferative (MP)-CMML: WBC > 20 × 109/l. By analysing EBMT Registry patients who underwent allo-HCT for CMML between 1997 and 2016, we aimed to determine the impact of this classification on transplantation outcome and to make a comparison with the conventional WHO classification (CMML-0/CMML-1/CMML-2). Patient grouping was based on the data registered at time of transplantation, with IMC replaced by peripheral blasts. Among 151 patients included in the analysis, 38% were classified as MD-CMML, 42% as MD/MP-CMML and 20% as MP-CMML. With a median survival of 17 months in the whole series, MD-CMML patients were distinguished as a low-risk group with higher CR rate at transplant and a longer post-transplant 2-year progression-free survival in comparison to others (44.5% vs 33.5%, respectively), whereas the WHO classification was superior in identifying high-risk patients (CMML-2) with inferior survival outcomes.

Autologous hematopoietic cell transplantation (auto-HCT) may be performed in multiple myeloma (MM) patients relapsing after a previous auto-HCT. For those without an adequate dose of stored stem cells, remobilization is necessary. This retrospective study included patients who, following disease relapse after the first auto-HCT(s), underwent stem cell remobilization and auto-HCT performed using these cells. There were 305 patients, 68% male, median age at salvage auto-HCT was 59 years. The median time to relapse after the first-line penultimate auto-HCT(s) was 30.6 months, the median follow-up after salvage auto-HCT 31 months. The 2- and 4-year non-relapse mortality (NRM) after the salvage auto-HCT was 5 and 9%, the relapse incidence 56 and 76%, respectively. Overall survival (OS) after 2 and 4 years was 76 and 52%, progression-free survival (PFS) 39 and 15%. In multivariable analysis an increasing interval between the penultimate auto-HCT and relapse was associated with better OS and PFS, later calendar year of salvage auto-HCT with better OS. In conclusion, salvage auto-HCT performed with cells remobilized after a previous auto-HCT was associated with acceptable NRM. The leading cause of failure was disease progression of MM, which correlated with a shorter interval from the penultimate auto-HCT to the first relapse.

BackgroundIn patients with acute leukemia, lymphoma and chronic malignancies, donor and/or recipient Epstein-Barr virus (EBV) seropositive status increases the risk of development of chronic graft-versus-host disease (cGVHD) after allo-hematopoietic cell transplantation (allo-HCT), while it has no influence on other transplant outcomes. No data are available on the impact of EBV serostatus on transplant outcomes in patients with nonmalignant hematological disorders.ObjectiveWe analyzed the influence of the recipient's (R) and donor's (D) EBV serostatus on transplant outcomes (overall survival (OS); relapse-free survival (RFS); relapse incidence (RI); nonrelapse mortality (NRM); acute graft-versus-host disease (aGVHD); cGVHD) in patients with nonmalignant hematological disorders undergoing allo-HCT.Patients and MethodsA total of 2,355 allo-HCTs performed between 1997 and 2016 for acquired bone marrow failure or hemoglobinopathies were included in this retrospective Registry megafile Infectious Diseases Working Party of the European Society of Blood and Marrow Transplantation (IDWP-EBMT) study.ResultsDemographics: The median age of recipient was 17.7 years (range: 0–77), and 50.8% were children. 79.0% of recipients and 75.4% of donors were EBV-seropositive. 67.8% had HCT from a matched family donor, 4.6% from a mismatched family donor, and 27.6% from an unrelated donor (UD). T-cell depletion was performed in vivo and ex vivo in 82.2% and 6.6% of patients, respectively. Conditioning regimen was myeloablative in 63.7% and reduced intensity conditioning (RIC) in 36.3% of patients. The median follow-up was 4.7 years. Transplant outcomes: EBV-seropositive recipients in comparison with EBV-seronegative recipients had lower OS (85.4% vs. 88.4%, p = 0.035) and higher NRM (10.0% vs. 6.4%, p = 0.018). No other significant differences were found for: RI, RFS, and aGVHD or cGVHD with respect to EBV pretransplant serostatus donor and/or recipient. Multivariate analysis: A trend toward higher risk of development of cGVHD (HR = 1.31; p = 0.081) and better survival (HR = 0.78; p = 0.087) in allo-HCT from EBV-seropositive donors was found. Allo-HCT in EBV-seropositive recipients had a trend toward lower risk of development of cGVHD (HR = 0.75; p = 0.065). When four subgroups (R−/D−, R−/D+, R+/D−, R+/D+ EBV serology) were analyzed, the EBV serostatus had no significant impact on OS, RFS, RI, NRM and development of aGVHD or cGVHD.ConclusionsAllo-HCT from EBV-seropositive versus EBV-seronegative donors are at 31% higher risk of cGVHD in patients with nonmalignant hematological disorders undergoing allo-HCT; however this difference is nonsignificant in multivariate analysis.

Objectives To describe the coinfections in invasive aspergillosis (IA), to identify factors associated with coinfections, and to evaluate the impact of coinfection on mortality. Patients and methods We conducted a monocentric retrospective study of consecutive putative, probable, or proven IA that occurred between 1997 and 2017. All coinfections, with an onset within 7 days before or after the first sign of aspergillosis, were identified. Factors associated with coinfections and mortality were analysed by multivariable analysis. Results Among the 690 patients with IA included in the study, the median age was 57 years (range 7 days to 90 years). A coinfection was diagnosed in 272/690 patients (39.4%, 95%CI 35.8–43.2). The location of this coinfection was pulmonary only in 131/272 patients (48%), bloodstream only in 66/272 patients (24%) and other/multiple sites in 75/272 patients (28%). Coinfections were bacterial (110/272 patients, 40%), viral (58/272, 21%), fungal (57/272, 21%), parasitic (5/272, 2%) or due to multiple types of pathogens (42/272, 15%). Factors associated with a coinfection in adjusted analysis were: allogeneic haematopoietic stem-cell transplantation (OR 2.3 (1.2–4.4)), other haematological malignancies (OR 2.1 (1.2–3.8)), other underlying diseases (OR 4.3 (1.4–13.6)), lymphopenia (OR 1.7 (1.1-2.5)), C-reactive protein >180 mg/L (OR 1.9 (1.2–3.0)), fever (OR 2.4 (1.5–4.1)), tracheal intubation (OR 2.6 (1.5–4.7)), isolation of two or more different Aspergillus species (OR 2.7 (1.1–6.3)), and the presence of non-nodular lesions on chest computed tomography (OR 2.2 (1.3–3.7) and OR 2.2 (1.2–4.0)). Coinfections were independently associated with a higher mortality at week 12 (adjusted HR 1.5 (1.1–1.9), p Conclusions Coinfections are frequent in IA patients and are associated with higher mortality.

Purpose: Relapse after allogeneic hematopoietic cell transplantation (allo-HCT) remains the first cause of transplant failure in patients with Philadelphia-positive (Ph+) acute lymphoblastic leukemia (ALL). In other hematologic malignancies, therapeutic advances resulted in significant improvement over time in survival of patients relapsing after transplant. Experimental Design: We compared outcomes at European Society for Blood and Marrow Transplantation (EBMT) participating centers of 899 adult patients with Ph+ ALL who relapsed between 2000 and 2019 after allo-HCT performed in first complete remission. Median follow-up for alive patients was 56 months. Results: Overall, 116 patients relapsed between 2000 and 2004, 225 between 2005 and 2009, 294 between 2010 and 2014, and 264 between 2015 and 2019. Patient and transplant characteristics were similar over the four time periods except for a progressive increase in unrelated donors, peripheral blood stem cells, reduced intensity conditioning, and in vivo T-cell depletion and a progressive decrease in total body irradiation. The 2-year overall survival (OS) after relapse increased from 27.8% for patients relapsing between 2000 and 2004 to 54.8% for 2015 and 2019 (P = 0.001). A second allo-HCT within 2 years after relapse was performed in 13.9% of patients resulting in a 2-year OS of 35.9%. In multivariate analysis, OS from relapse was positively affected by a longer time from transplant to relapse and the year of relapse. Conclusions: We observed a major progressive improvement in OS from posttransplant relapse for patients with Ph+ ALL over the years, likely multifactorial including transplant-related factors, posttransplant salvage, and improvement in supportive care. These large-scale real-world data can serve as a benchmark for future studies in this setting. See related commentary by Gale, p. 813

International audience; Objectives: The impact of conventional treatment for acute myeloid leukemia (AML) on the nutritional, cognitive, and functional status of elderly patients is seldom studied. This assessment was performed in the context of the LAMSA 2007 trial.Methods: The trial enrolled 424 patients with de novo AML. Among them, 316 benefited from geriatric assessment (GA) including nutritional, cognitive, and functional status and were scored according to Eastern Cooperative Oncology Group (ECOG) and sorror for the prediction of treatment toxicity, morbidity, and mortality. Patients were investigated at diagnosis for three times during follow-up.Results: This study showed that AML and its treatment have no impact on cognitive (P = .554) nor functional status (P = .842 for Activity of Daily Living and P = .087 for Instrumental Activities of Daily Living). The nutritional status improved over time (P = .041). None of these three parameters at baseline, associated or not with ECOG and sorror scores, impacted survivals or toxicities.Conclusions: The cognitive, functional, and nutritional status had no impact in this cohort of fit elderly AML patients without unfavorable cytogenetics. The GA tools used provided no additional information compared with ECOG and sorror scores, to predict toxicity, morbidity, or mortality due to intensive chemotherapy.

International audience; The association of Cyclosporine A (CsA) and mycophenolate mofetil (MMF) has increased in the setting of reduced intensity conditioning (RIC). Nevertheless, the use of CsA or CsA+MMF has not been reported in a large and uniform cohort. We analyzed 497 patients with acute myeloid leukemia in complete remission (CR) who underwent matched unrelated donor (MUD) hematopoietic stem cell transplantation (HSCT). All patients received a fludarabine busulfan RIC regimen and anti-thymocyte globulin (ATG) with either CsA alone or in combination with MMF. The cumulative incidence (CI) of grade II-IV acute GvHD was 27% (95% CI 21-33%) for CsA and 33% (95% CI 27-38%) for CsA+MMF (p = 0.25). The 2-year CI of chronic GvHD was 38% (95% CI 31-45%) and 33% (95% CI 28-39%) for the CsA and the CsA+MMF group, respectively (p = 0.26). On multivariate analysis, no statistically significant differences with respect to relapse incidence (RI), non-relapse mortality (NRM), leukemia-free survival (LFS), overall survival (OS), acute and chronic GvHD were found between the two groups, also when conducting a subgroup analysis in peripheral blood stem cells (PBSC) recipients. Our results support the importance of randomized trial to identify patients who could benefit from the addition of MMF in MUD HSCT.

Toxoplasmosis is a life-threatening infection in allogenic stem cell recipients usually involving the brain or retina and more rarely lungs or bone marrow. Digestive involvement has only been reported in AIDS patient. We report about a 38-year-old man who received a haploidentical allograft for acute myeloid leukemia and developed an unusual digestive presentation with severe protein-losing enteropathy following grade III acute digestive GvHD treated with steroids and ruxolitinib. Diagnosis was brought up because of concomitant brain involvement. Digestive symptoms fully recovered after treatment with sulfamethoxazole-trimethoprim. Digestive toxoplasmosis could be considered as a differential diagnosis or complication of severe digestive GvHD.

During vertebrate, definitive hematopoietic stem cells (HSCs) are first generated in the aorta-gonad-mesonephros (AGM) region of the posterior embryo.1 We previously showed that the angiotensin-converting enzyme (ACE) is a cell-surface marker of human HSCs in both adult bone marrow (BM)2 and all hematopoietic niches developmentduring human ontogeny.3 In the embryo, ACE identifies HSCs associated with the ventral side of the aortic endothelium (in the AGM region) and of vitelline and umbilical arteries, both in humans3 and mice.4 ACE is a key component of the renin-angiotensin system (RAS), catalyzing the production of angiotensin II (AngII),5 which we have recently shown to be involved in hematopoietic emergence during ontogeny.4 ACE overexpression, leading to AngII increase, has also been reported in the BM of patients with acute myeloid leukemia (AML), influencing malignancy6,7 ; however, its mechanisms of regulation are still unknown.8 The caudal-related homeobox gene 2 (CDX2) encodes an important transcription factor involved in tissue expansion and patterning of the posterior embryo.9,10 At midgestation, it becomes limited to the presumptive mid-/hindgut endoderm and maintains selectively in the adult intestinal epithelium11 where it has tumor-suppressor activity.12-14 Conversely, although CDX2 is not expressed in adult HSCs, ectopic expression occurs in 80% of acute leukemia, which is considered a driver of leukemogenesis.15-17 Here, we investigated the ACE and CDX2 expression patterns during human and mouse hematopoietic development, as well as in AML, and we conducted functional assays supporting that CDX2 participates in ACE regulation.

Despite advances in drug treatments, multiple myeloma almost always remains a fatal disease. Technical advances in radiotherapy enable total marrow irradiation (TMI) by intensity-modulated radiation therapy (IMRT) to better protect healthy tissues and organs. This therapeutic modality can be proposed in conditioning for an autograft of peripheral stem cells (PSC). The purpose of this chapter is to report the French experience in first-recurrence multiple myeloma.

International audience; Graft-versus-host disease (GVHD) and cytomegalovirus (CMV)-related complications are leading causes of mortality after unrelated-donor hematopoietic cell transplantation (UD-HCT). The non-conventional MHC class I gene MICB, alike MICA, encodes a stress-induced polymorphic NKG2D ligand. However, unlike MICA, MICB interacts with the CMV-encoded UL16, which sequestrates MICB intracellularly, leading to immune evasion. Here, we retrospectively analyzed the impact of mismatches in MICB amino acid position 98 (MICB98), a key polymorphic residue involved in UL16 binding, in 943 UD-HCT pairs who were allele-matched at HLA-A, -B, -C, -DRB1, -DQB1 and MICA loci. HLA-DP typing was further available. MICB98 mismatches were significantly associated with an increased incidence of acute (grade II-IV: HR, 1.20; 95% CI, 1.15 to 1.24; P < 0.001; grade III-IV: HR, 2.28; 95% CI, 1.56 to 3.34; P < 0.001) and chronic GVHD (HR, 1.21; 95% CI, 1.10 to 1.33; P < 0.001). MICB98 matching significantly reduced the effect of CMV status on overall mortality from a hazard ratio of 1.77 to 1.16. MICB98 mismatches showed a GVHD-independent association with a higher incidence of CMV infection/reactivation (HR, 1.84; 95% CI, 1.34 to 2.51; P < 0.001). Hence selecting a MICB98-matched donor significantly reduces the GVHD incidence and lowers the impact of CMV status on overall survival.

BACKGROUND: Allogeneic hematopoietic cell transplantation (allo-HCT) is a standard of care for adults with high-risk acute lymphoblastic leukemia (ALL) in first or subsequent complete remission (CR). Myeloablative total body irradiation (TBI) combined with cyclophosphamide (Cy) is the most frequently used conditioning regimen. In order to reduce toxicity Cy may be replaced by fludarabine (Flu). The goal of this registry-based, retrospective study was to compare outcomes of allo-HCT following TBI/Cy vs. TBI/Flu conditioning. PATIENTS AND METHODS: Included in the analysis were 2255 patients aged 18-65 years, treated with allo-HCT from either a matched sibling (43%) or unrelated (57%) donor in CR1 (83%) or CR2 (17%), between the years 2010-2020. Patients with Ph(-) B-ALL, Ph(+) B-ALL, and T-ALL were represented in equal proportions. TBI 12Gy + Cy was used in 2105 cases while TBI 12Gy + Flu was administered to 150 patients. Patients treated with TBI/Flu were significantly older (median 35 years vs. 33 years, p=0.006), with poorer Karnofsky performance score ( RESULTS: Engraftment rate was 99% for both TBI/Cy and TBI/Flu patients. In a univariate analysis the use of TBI/Cy as compared to TBI/Flu was associated with a tendency to reduced incidence of relapse (24% vs. 29% at 2 years, p=0.1), increased incidence of grade 2-4 acute graft versus host disease (GVHD, 35.5% vs. 28%, p=0.08) and improved leukemia-free survival (LFS, 62% vs. 57%, p=0.18). The rates and causes of non-relapse mortality (NRM) did not differ significantly between the two conditioning groups. In a multivariate model adjusted for other prognostic factors, TBI/Cy conditioning was associated with reduced risk of relapse (HR=0.69, p=0.049) and increased risk of grade 2-4 acute GVHD (HR=1.57, p=0.03) without significant effect on other transplantation outcomes. An additional analysis was performed with TBI/Cy treated patients (n=132) matched strictly to those treated with TBI/Flu (n=132) in terms of disease subtype, disease status and donor type with the nearest neighbor for patient age, patient and donor sex, in vivo T-cell depletion, Karnofsky score and source of stem cells; the use of TBI/Cy as compared to TBI/Flu was associated with significantly reduced rate of relapse (18% vs. 30% at 2 years, p=0.015) and a tendency to an improved LFS (65% vs. 59%, p=0.07) and overall survival (OS, 73% vs. 68%, p=0.16) without effect on NRM and GVHD. CONCLUSIONS: The use of myeloablative TBI/CY as conditioning prior to allo-HCT for adult patients with ALL in CR1 or CR2 is associated with stronger anti-leukemic effect leading to significantly lower relapse rate compared to TBI/Flu and therefore should be likely considered a preferable regimen. Disclosures Giebel: Janssen: Honoraria, Speakers Bureau; Pfizer: Consultancy, Honoraria, Speakers Bureau; Novartis: Consultancy, Honoraria, Speakers Bureau; Amgen: Consultancy, Honoraria, Speakers Bureau. Labopin: Jazz Pharmaceuticals: Honoraria. Socie: Alexion: Research Funding. Yakoub-Agha: Jazz Pharmaceuticals: Honoraria. Kröger: Novartis: Research Funding; Riemser: Honoraria, Research Funding; Sanofi: Honoraria; Neovii: Honoraria, Research Funding; Jazz: Honoraria, Research Funding; Gilead/Kite: Honoraria; Celgene: Honoraria, Research Funding; AOP Pharma: Honoraria. Forcade: Novartis: Consultancy, Other: Travel Support, Speakers Bureau; Gilead: Other: Travel Support, Speakers Bureau; Jazz: Other: Travel Support, Speakers Bureau; MSD: Other: Travel Support. Huynh: Jazz Pharmaceuticals: Honoraria. Spyridonidis: Menarini: Current Employment. Perić: therakos: Honoraria; servier: Honoraria; MSD: Honoraria; Astellas: Honoraria; NOVARTIS: Honoraria; Abbvie: Honoraria; Pfizer: Honoraria. Mohty: Pfizer: Honoraria; Celgene: Honoraria, Research Funding; Amgen: Honoraria; Astellas: Honoraria; Gilead: Honoraria; Jazz: Honoraria, Research Funding; Janssen: Honoraria, Research Funding; Novartis: Honoraria; Bristol Myers Squibb: Honoraria; Takeda: Honoraria; Sanofi: Honoraria, Research Funding; Adaptive Biotechnologies: Honoraria.

Background: High dose melphalan (HDM) followed by autologous hematopoietic stem cell transplantation (ASCT) is widely used in multiple myeloma (MM) patients as upfront and salvage therapy. However, the safety and efficacy of ASCT in patients with renal insufficiency (RI) is controversial, which have led to an inconsistent arbitrary cut-off for creatinine clearance (CrCl) for performing ASCT. Here we analyzed prospectively the outcomes of MM patients with severe RI who underwent ASCT. Methods: We enrolled prospectively 50 newly diagnosed MM patients who had a serum CrCl of Results: The patients characteristics at enrollment are given in Table 1. We focused on 44 patients who were beyond 3 months post-ASCT. Light chain MM was frequent (12%), 10% had high risk cytogenetics, 36% increased serum LDH and 10% extramedullary disease. Induction chemotherapies included bortezomib plus IMiDs in 25/44 patients with ≥2 lines of chemotherapy in 12/44. The pre-transplant disease status was sCR in =5%, CR in =15%, VGPR in =39%, and PR in =41% of patients. The number of days of cytapheresis was 2 or less in 95% of cases and the median number of CD34+ cells collected was 3.3 x 106 (1.3-9.5). The median time from diagnosis to ASCT was 175 days (103-307). HDM was 140 mg/m2 in 42/44 patients and 200 mg/m2 in 2/44. All, except two, received consolidation post ASCT (34% missing) and 52% had maintenance therapy (all lenalidomide except two receiving bortezomib) and 7% had no maintenance (41% pending). Toxicity: We observed one death during the first 100 days post-ASCT, secondary to a septic shock on day 42. The median time to neutrophil engraftment was 12 days (9-68) and to platelet engraftment 13 days (10-70). Among patients receiving RBC transfusions (75%) and platelet transfusions (84%), the median number of RBC transfusions was 3 (1-6) and that of platelet transfusions was 3 (1-10). Response: Nine patients (70%) achieved dialysis independence from the time of diagnosis: 13 patients were on dialysis at diagnosis, 5 at the time of ASCT and 4 three months post-ASCT. Renal function improved post-ASCT in 34% of patients, 14% moving from a CrCl of Conclusions: In this preliminary analysis, HDM with ASCT proved to be safe and effective in MM patients with RI at transplant. We observed one death among 44 patients within the first 3 months post-ASCT. A more detailed report of the toxicity will be presented during the meeting along with the survival. Disclosures Vincent: takeda: Membership on an entity's Board of Directors or advisory committees, Other: Congress support; Celgene: Membership on an entity's Board of Directors or advisory committees, Other: Congress support; janssen: Membership on an entity's Board of Directors or advisory committees, Other: Congress support. Mohty:Jazz Pharmaceuticals: Consultancy, Honoraria, Research Funding, Speakers Bureau; BMS: Consultancy, Honoraria, Research Funding, Speakers Bureau; Novartis: Consultancy, Honoraria, Research Funding, Speakers Bureau; Stemline: Consultancy, Honoraria, Research Funding, Speakers Bureau; Janssen: Consultancy, Honoraria, Research Funding, Speakers Bureau; Celgene: Consultancy, Honoraria, Research Funding, Speakers Bureau; Takeda: Consultancy, Honoraria, Research Funding, Speakers Bureau; GSK: Consultancy, Honoraria, Research Funding, Speakers Bureau; Sanofi: Consultancy, Honoraria, Research Funding, Speakers Bureau; Amgen: Consultancy, Honoraria, Research Funding, Speakers Bureau. Karlin:AbbVie: Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Travel support; Celgene/Bristol-Myers Squibb: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Travel support; Takeda: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Travel support, personal fees; GlaxoSmithKline: Honoraria, Membership on an entity's Board of Directors or advisory committees; Celgene: Other: Personal fees; Sanofi: Honoraria; Amgen: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Travel support, personal fees; Janssen: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Travel support, personal fees. Morel:Janssen: Honoraria. Rubio:Medac: Consultancy; Gilead: Honoraria; MSD: Honoraria; Novartis: Honoraria; Neovii: Research Funding.

Cyclosporine A (CsA) alone or in combination with mycophenolate mofetil (MMF) has been used as graft-versus-host-disease (GvHD) prophylaxis since the development of reduced intensity conditioning (RIC). The association of CsA+MMF, while commonly used after transplantation from a matched unrelated donor (MUD), has never been tested in a large randomized prospective trial. We retrospectively investigated the outcomes of 497 adult patients with AML in complete remission (CR) undergoing a MUD transplant between 2007-2017 using CsA+MMF or CsA alone as GvHD prophylaxis, and registered with the ALWP of the EBMT. Patients had CsA alone (n=183) or CsA+MMF (n=314) as GvHD prophylaxis. All underwent a RIC regimen with fludarabine and busulfan and received anti-thymocyte globulin. The median age at transplant was similar (59 and 60 years in the CsA and CsA+MMF group). The median follow-up was not significantly different between the two groups (33 vs 34 months in CsA and CsA+MMF, respectively). Disease status at transplant was first complete remission (CR1) for 81% in CsA group and 86% in CsA+MMF group (p=NS). Peripheral blood stem cells (PBSC) was the graft source in 93% of patients receiving CsA alone and in 96% of patients who received CsA+MMF (p=0.17). All but 2 patients engrafted. The 100 day cumulative incidence (CI) of grade II-IV and grade III-IV acute GvHD were 30% and 10%, respectively. The 2-year CI of chronic GvHD was 35% and CI of extensive cGvHD was 15%. The 2-year CI of non-relapse mortality (NRM) and relapse were 19% and 25%, respectively. Disease recurrence (n=31), GvHD (n=20) and infection (n=17) were the most common causes of death in the CsA group. Relapse (n=53), GvHD (n=28) and infection (n=28) were the most frequent causes of death in the CsA+MMF group. The 2-year GVHD-free relapse-free survival (GRFS), leukemia- free survival (LFS), and overall survival (OS) were 45%, 56% and 60%, respectively. On multivariate analysis (MVA), no statistically significant differences between the two groups with respect to relapse, NRM, LFS, OS, acute and chronic GvHD were identified. A positive cytomegalovirus serology of the donor was associated with higher NRM [HR=2.03, p In a subgroup analysis in patients in CR1 who received PBSC, no differences were detected between the two groups for relapse, NRM, LFS, OS, or aGvHD. Patients who received CsA alone tended to have a higher cGvHD (p=0.05). However, this finding was not statistically significant in MVA. We observed comparable outcomes in AML patients in CR1 who underwent MUD transplantation and RIC with CsA+MMF or CsA alone as GvHD prophylaxis. This suggests that both strategies may be considered valid approaches. Randomized trials are needed to further assess which patients could benefit from the addition of MMF in GvHD prophylaxis

Monosomy 7 or deletion 7q (-7/7q-) is the most frequent adverse cytogenetic features reported in acute myeloid leukemia (AML), and is a common indication for allogeneic stem cell transplantation (SCT). Nevertheless, -7/7q- occurs frequently with other high-risk cytogenetic abnormalities such as complex karyotype (CK), monosomal karyotype (MK), monosomy 5 or deletion 5q (-5/5q-), 17p abnormalities (abn(17p)) or inversion of chromosome 3 (inv(3)), the presence of which may influence the outcomes after SCT. A total of 1109 patients were allocated to this study. Two-year probability of leukemia-free survival (LFS) and overall survival (OS) were 30% and 36%, respectively. Two-year probability of non-relapse mortality (NRM) was 20%. We defined five different cytogenetic subgroups: the "-7/7q- +/- CK group- designated group1," the "MK group-designated group 2," the "-5/5q- group- designated group 3," the "abn(17p) group- designated group 4" and the "inv(3) group- designated group 5." The 2-year probability of LFS in first remission was 48% for group 1, 36.4% for group 2, 28.4% for group 3, 19.1% for group 4 and 17.3% for group 5, respectively (P

The use of autologous haematopoietic stem cell transplantation (AHSCT) in autoimmune disease (AD) patients has increased progressively worldwide. We retrospectively analysed the long-term outcome of AHSCT for AD reported to the French Society for Bone Marrow Transplantation and Cellular Therapy (SFGM-TC). All French AD patients (≥ 18 years at transplant) with a first AHSCT between 1997 and 2013 were included. Primary data were derived from the European Society for Blood and Marrow Transplantation (EBMT) registry, and additional data were obtained through a specific questionnaire designed for the study. Primary end-point was overall survival (OS). Secondary end points were progression-free survival (PFS) and non-relapse mortality (NRM). Ninety-four AD patients were included, of whom 71% suffered from rheumatologic diseases (n = 67, including 56 systemic sclerosis (SSc)), 16% from neurological disease (n = 15, including 14 multiple sclerosis (MS)) and 13% from various other AD (n = 12). After a median (interquartile range, IQR) follow-up of 83 months (38–130), OS at 5 and 10 years were 77% (95% CI 68.5–86.2) and 64% (95% CI 51.7–76.3), and for PFS 51% (95% CI 40.4–61.6) and 44% (95% CI 32.8–55.3), respectively. Overall, NRM was 8.7% (95% CI 4.0–15.5) at day 100, 9.8% (95% CI 4.8–16.9) at 5 years and 13.6% (95% CI 6.9–22.5) at 10 years. This first SFGM-TC retrospective report shows long-term benefit of AHSCT in AD patients with acceptable toxicity.

Purpose We developed a prognostic scoring system to evaluate the prognosis of myelodysplastic syndrome (MDS) patients surviving more than 100 days allogeneic hematopoietic cell transplantation after (allo-HCT). Patients and methods We performed a landmark analysis on a derivation cohort of 393 cases to identify prognostic factors for 3-year overall survival. Potential predictor variables included demographic and clinical data, transplantation modalities and early post-transplant complications. The scoring system was tested against a validation cohort which included 391 patients. Results Complications occurring before day 100 such as relapse [HR = 6.7; 95%CI, 4.5-10.0] (4 points), lack of platelet recovery [HR, 3.6; 95%CI, 2.2-5.8] (2 points), grade-II acute GVHD [HR = 1.7; 95%CI, 1.2-2.5] (1 point) and grade-III/IV [HR = 2.6; 95%CI, 1.8 -3.8] (2 points) were the only independent predictors of 3-year OS. The 3-year OS associated with low (0), intermediate (1-3) and high (≥4) risk scores was respectively 70%, 46% and 6%. The model performed consistently in both cohorts, with good calibration. Conclusion This post-transplant scoring system is a powerful predictor of outcome after allo-HCT for MDS, and can provide useful guidance for clinicians. Additional studies are required to evaluate this scoring system for other hematologic malignancies.

Several approaches have been developed to overcome historical barriers associated with poor outcomes in the setting of HLA-haploidentical allogeneic transplantation (HaploSCT). Here, we examine the outcome of patients with various hematological disorders undergoing HaploSCT with high-dose, post-transplantation cyclophosphamide. We performed a retrospective study on 381 patients from 30 centers between January 2013 and December 2015. At the last follow-up, a total of 1058 infectious episodes were diagnosed, affecting 90.3% of the cohort. Median time to first infection was 13 days for bacterial, 32 days for viral and 20 days for fungal infections. Around 41% of these infections were of bacterial origin and 35% of viral origin, among which 48.8% of patients presented CMV reactivation. Median of GVHD relapse-free survival, progression-free survival and overall survival were 7.1 months, 19.9 months and 33.5 months, respectively. HSCT procedure was the primary or contributing cause of death (55.6%), followed by relapse of the original disease (34.2%). Infections accounted for 45.7% of the HSCT-related deaths. The present multicenter data on a large cohort of patients receiving HaploSCT with PTCy confirmed the feasibility of the procedure with an acceptable incidence of infectious complications, not different as compared to other haploidentical platforms or HLA-matched transplantation.

Background. Acute myeloid leukemia (AML) with unfavorable cytogenetics remains a therapeutic challenge. We previously established that ex vivo exposure of AML blasts to eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA) or fish oil emulsion (FO) induces Nrf2 pathway activation, metabolic switch and cell death (Picou et al., Pharmacol Res 2018;136:45-55). Objectives. The FILO group launched a pilot clinical study to evaluate the feasibility, safety and efficacy of the adjunction of a commercial FO emulsion (OMEGAVEN) to 3+7 in untreated AML with unfavorable cytogenetics. Patients and methods. The FAMYLY trial was a multicenter single-arm phase II study. Eligible patients had a diagnosis of untreated AML with unfavorable cytogenetics, 18 years old or above. For patients with WBC < 30 G/L, FO was administered at 2 mL/kg/d IV 2 days before 3+7 induction chemotherapy (daunorubicin 60 mg/m² days 1-3 and cytarabine 200 mg/m²/d as a continuous infusion days 1-7), until day 7 of induction. For patients with WBC >= 30 G/L, FO and 3+7 were started concomitantly, and FO was administered until day 9. The primary objective was complete response (CR) on the BM aspirate at the end of induction. Data from 75 patients with adverse cytogenetics and treated with daunorubicin and cytarabine in LAM2001 study (Lioure et al., Blood 2012) was used as a historical control. Serial blood samples were collected before treatment, and on days 1 and 3 after start of treatment, to evaluate the expression of NRF-2 target genes and antioxidant enzymes by RT-qPCR. Results. Thirty patients were included. The median age was 54 years (range: 30-64 years), and only 3 patients were hyperleukocytic. FO administration raised the plasma levels of EPA and DHA (p Conclusions. Altogether, FO emulsion adjunction to 3+7 is feasible and safe. Although CR rate improvement was not shown in this cohort of high-risk patients, further research aiming at finding the sufficient dose to trigger an NRF-2 response in vivo should be considered. ClinicalTrials.gov identifier: NCT01999413. Disclosures No relevant conflicts of interest to declare. OffLabel Disclosure: OMEGAVEN (fish oil emulsion) in Acute Myeloid Leukemia

To find out prognostic factors and to investigate different therapeutic approaches, we report on 147 consecutive patients who relapsed after allogeneic hematopoietic stem cell transplantation (allo-HSCT) for myelodysplastic syndrome (MDS). Sixty-two patients underwent immunotherapy (IT group, second allo-HSCT or donor lymphocyte infusion), 39 received cytoreductive treatment alone (CRT group) and 46 were managed with palliative/supportive cares (PSC group). Two-year rates of overall survival (OS) were 32%, 6%, and 2% in the IT, CRT, and PSC groups, respectively (P.001). In multivariate analysis, 4 factors adversely influenced 2-year rates of OS: history of acute graft-versus-host disease (hazard ratio [HR], 1.83; 95% confidence interval [CI], 1.26 to 2.67; P = .002), relapse within 6 months (HR, 2.69; 95% CI, .82 to 3.98; P.001), progression to acute myeloid leukemia (HR, 2.59; 95% CI, 1.75 to 3.83; P.001), and platelet count50 G/L at relapse (HR, 1.68; 95% CI, 1.15 to 2.44; P = .007). A prognostic score based on those factors discriminated 2 risk groups with median OSs of 13.2 versus 2.4 months, respectively (P.001). When propensity score, prognostic score, and treatment strategy were included in Cox model, immunotherapy was found to be an independent factor that favorably impacts OS (HR, .40; 95% CI, .26 to .63; P.001). In conclusion, immunotherapy should be considered when possible for MDS patients relapsing after allo-HSCT.

Inconsistent results have been reported regarding the influence of graft composition on the incidence of graft versus host disease (GVHD), disease control and survival after reduced-intensity conditioning (RIC) allogeneic peripheral blood stem cell transplantation (allo-PBSCT). These discrepancies may be at least in part explained by the differences in disease categories, disease status at transplant, donor type and conditioning. The current retrospective EBMT registry study aimed to analyze the impact of CD3+ and CD34+ cells dose on the outcome of RIC allo-PBSCT in patients with acute myelogenous leukemia (AML) in first complete remission, allografted from HLA-matched unrelated donors (10 of 10 match). We included 203 adults. In univariate analysis, patients transplanted with the highest CD3+ and CD34+ doses (above the third quartile cut-off point values, >347 x 10^6/kg and >8.25 x 10^6 /kg, respectively) had an increased incidence of grade III-IV acute (a) GVHD (20% vs. 6%, P = .003 and 18% vs. 7%, P = .02, respectively). There was no association between cellular composition of grafts and transplant-related mortality, AML relapse, incidence of chronic GVHD and survival. Neither engraftment itself nor the kinetics of engraftment were affected by the cell dose. In multivariate analysis, CD3+ and CD34+ doses were the only adverse predicting factors for grade III-IV aGVHD (HR = 3.6; 95%CI: 1.45-9.96, P = .006 and 2.65 (1.07-6.57), P = .04, respectively). These results suggest that careful assessing the CD3+ and CD34+ graft content and tailoring the cell dose infused may help in reducing severe acute GVHD risk without negative impact on the other transplantation outcomes. ispartof: Oncotarget vol:7 issue:19 pages:27255-27266 ispartof: location:United States status: published

Graft-versus-host disease (GVHD) is among the most challenging complications in unrelated donor hematopoietic cell transplantation (HCT). The highly polymorphic MHC class I chain-related gene A, MICA, encodes a stress-induced glycoprotein expressed primarily on epithelia. MICA interacts with the invariant activating receptor NKG2D, expressed by cytotoxic lymphocytes, and is located in the MHC, next to HLA-B. Hence, MICA has the requisite attributes of a bona fide transplantation antigen. Using high-resolution sequence-based genotyping of MICA, we retrospectively analyzed the clinical effect of MICA mismatches in a multicenter cohort of 922 unrelated donor HLA-A, HLA-B, HLA-C, HLA-DRB1, and HLA-DQB1 10/10 allele-matched HCT pairs. Among the 922 pairs, 113 (12.3%) were mismatched in MICA. MICA mismatches were significantly associated with an increased incidence of grade III-IV acute GVHD (hazard ratio [HR], 1.83; 95% confidence interval [CI], 1.50-2.23; P < .001), chronic GVHD (HR, 1.50; 95% CI, 1.45-1.55; P < .001), and nonelapse mortality (HR, 1.35; 95% CI, 1.24-1.46; P < .001). The increased risk for GVHD was mirrored by a lower risk for relapse (HR, 0.50; 95% CI, 0.43-0.59; P < .001), indicating a possible graft-versus-leukemia effect. In conclusion, when possible, selecting a MICA-matched donor significantly influences key clinical outcomes of HCT in which a marked reduction of GVHD is paramount. The tight linkage disequilibrium between MICA and HLA-B renders identifying a MICA-matched donor readily feasible in clinical practice.

Introduction Standard first line treatment for mantle cell lymphoma (MCL) in fit patients is induction with cytarabine containing chemo-immunotherapy and a consolidative autologous stem cell transplant (ASCT). Responses are excellent but there is a continuous pattern of relapse. Progression within 24 months (POD24) of standard first line therapy including ASCT has been shown to predict poorer outcomes, which may be ameliorated by alloSCT. Ibrutinib, a Bruton's Tyrosine Kinase inhibitor, is an effective therapy for relapsed MCL. However, there is a paucity of published data of ibrutinib's efficacy in patients treated at relapse after standard first line treatment with ASCT and very little regarding the impact of POD24 on outcomes after ibrutinib and outcomes of subsequent alloSCT. Methods This was a retrospective analysis of the EBMT registry. The inclusion criteria were: patients with MCL ≥18 years old, 1st line therapy containing cytarabine and rituximab, ASCT in first CR/PR between 2009 and 2016 and received ibrutinib for 1st relapse after ASCT. POD24 was defined as progressive disease in less than 24 months after ASCT. Results 66 patients met the inclusion criteria (Table 1) relapsing at a median of 25 months (range 15-33) post ASCT. Thirty-two patients progressed in less than 24 months after ASCT. Ibrutinib was started at a median of 30 days after relapse (range 10-54). Overall response rate (ORR) was 74% [32 (48%) achieving CR and 18 (27%) PR]. The median duration of response was 10.1 months (available for 28 patients). There were no significant differences in the duration of response to ibrutinib for patients with POD24 (median: 10.4 months, IQR 4.0-15.4) compared to POD after 24 months or more (POD≥24) [(median 9.8 months, IQR 6.5-20.7) p=0.9]. Relapse after/during ibrutinib occurred in 21 patients (33%) at a median of 12 months (range 1-34). 13 of those patients were on ibrutinib at the time of relapse and the remaining 8 after ibrutinib had been stopped for a SCT or because of toxicity. Ibrutinib therapy continues at last follow-up in 23 (35%) patients. Ibrutinib was stopped for the following reasons: 16 patients subsequent SCT, 13 relapse, 5 toxicity (cytopenia, infection, tachycardia, hepatitis and poor tolerance, 1 case each), 9 other/unknown reasons. Second SCT was undertaken in 23 patients (22 alloSCT, 1 ASCT), 16 of whom were in CR/PR after only ibrutinib at the time of relapse. For alloSCT recipients, the donor was MUD in 11, MSD in 5 and mismatch related in 6. The majority (n=19) had reduced intensity conditioning. 50% of the patients developed acute GvHD and 50% chronic GvHD (3 extensive). With a median follow up of 17 months post alloSCT, 18 (63%) are in remission. There were no significant differences in PFS (p=0.173) or OS (p=0.336) post alloSCT for patients with POD24 and POD≥24. At last follow up (median follow-up of 22 months after starting ibrutinib), 35 (71%) patients were in CR and 4 (8%) in PR. 17 patients have died; the most common reason was MCL (14 patients), 2 deaths were secondary to alloSCT toxicity and in 1 case the cause of death was unknown. 2-year OS after starting ibrutinib was 72% (69% for alloSCT patients) and 2-year PFS 62%. PFS after starting ibrutinib was significantly better for patients with POD≥24 compared to those with POD24 (72% vs. 53% at 2 years post ASCT, p=0.017) and this translated to an OS benefit (80% vs. 68% at 2 years post ASCT, p=0.019) (figures 1 and 2). Conclusion Ibrutinib therapy did not overcome the poor outcome for patients with POD24 after first line therapy and although there was a high ORR to ibrutinib the median duration of response is only 10.1 months. AlloSCT should therefore be undertaken if possible, in our retrospective cohort of patients it appeared to overcome the poor prognosis of POD24 patients. Disclosures Hunter: Jazz pharamceuticals: Honoraria, Other: speaker fees, Meeting attendance support; Novartis: Honoraria, Other: speaker fees; celegene: Other: Meeting attendance support. Peggs:Autolus: Membership on an entity's Board of Directors or advisory committees; Gilead: Consultancy, Speakers Bureau. Foà:Incyte: Consultancy, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Roche: Consultancy, Speakers Bureau; Abbvie: Consultancy, Speakers Bureau; Abbvie: Consultancy, Speakers Bureau; Janssen: Consultancy, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Pfizer: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Novartis: Consultancy, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Novartis: Consultancy, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Amgen Inc.: Consultancy, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Shire: Consultancy, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Shire: Consultancy, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Janssen: Consultancy, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Amgen Inc.: Consultancy, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Pfizer: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Celltrion: Membership on an entity's Board of Directors or advisory committees; Incyte: Consultancy, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Roche: Consultancy, Speakers Bureau; Celltrion: Membership on an entity's Board of Directors or advisory committees. Pillai:Celgene: Honoraria. Mufti:Celgene Corporation: Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Cellectis: Membership on an entity's Board of Directors or advisory committees, Research Funding.

Introduction Myeloproliferative Neoplasm (MPN) unclassifiable (MPN-U), is a heterogeneous disease that presents with an MPN-type clinical/ histological phenotype yet fails to meet diagnostic criteria for other MPN entities. Incidence is Methods This registry-based analysis was approved by the Chronic Malignancies Working Party of the EBMT. Patient selection was performed by identifying adult patients who underwent first allo-HCT for MPN-U between 2000-2015, using either Reduced Intensity Conditioning (RIC) or Myeloablative conditioning (MAC) as defined by standard EBMT criteria. Further data collection requests (MED-C) forms were sent to centres to improve data completeness. Statistical analyses were performed with SPSS 22 (SPSS Inc./IBM, Armonk, NY) and R. Overall Survival (OS) was calculated from the date of transplant until death or last observation alive. Cumulative incidence functions were used to estimate Non-Relapse Mortality (NRM) and Relapse Incidence (RI) within a competing risk setting. Results A total of 70 patients, 48 (69%) male and 22 (31%) female, with a confirmed diagnosis of MPN-U were analysed. Median age was 57 years (range (r), 22-70 years). Of these patients, 37 (53%) underwent allo-HCT in the period 2001-2010 and 33 (47%) between 2011-2015. MAC regimens were utilised in 31 (44%) patients while 39 (56%) received RIC. Patients were most frequently transplanted within the first two years from diagnosis, with a median time to allo-HCT of 13 months (r, 3-244 months). Diagnostic karyotype was normal in 36 (51%) and abnormal in 23 (33%) patients, with data missing for 11 (16%) patients. A total of 45 (64%) patients had received prior treatment, 23 (33%) patients were untreated and data was incomplete in 2 (3%) patients. Regarding donor type, 27 (39%) patients had a Matched Sibling Donor (MSD) and 43 (61%) an Unrelated Donor (URD). Most frequent conditioning regimens were TBI-based in the MAC cohort and Fludarabine-Busulphan in the RIC cohort. A trend towards higher rates of delayed/failed engraftment was noted in the RIC compared to MAC cohort (p=0.09). Where successful, median time to neutrophil engraftment in both cohorts was similar (18 days for MAC and 17 for RIC) and both platforms demonstrated similar platelet engraftment times (17.5 days). Incidence of grade II-IV aGVHD at 3 months was higher in the MAC (37%) compared to RIC cohort (16%; p=0.05) and the 12-month cumulative incidence of cGVHD for MAC was 52% (95%CI: 32.4, 71.6) and for RIC 32.1% (95%CI: 14.8, 49.4; p=0.117)). Median follow-up was 87 months (minimum and maximum of censored cases: 31 and 196 months). The median OS estimates at 1, 3 and 5-year were 77%, 55% and 42% (MAC) and 59%, 44% and 41% (RIC), respectively (p=0.33). No significant difference existed in OS rates between those who had pre-transplant therapy versus not. Relapse remained significant: cumulative incidences of relapse at 1,3 and 5-years were 10%, 23% and 27% (MAC) and 28%, 36% and 36% (RIC), respectively (p=0.28). NRM probabilities at 1, 3 and 5-years post allo-HCT were also considerable: 19%, 29%, and 34% (MAC) and 28%, 28% and 28% (RIC), respectively (p=0.84). Main causes of NRM were infection and GVHD. Univariate analysis associated use of an URD with a significantly worse OS and NRM compared with MSD. Moreover, the presence of abnormal karyotype at time of allo-HCT was associated with a trend towards a higher risk of relapse (p=0.06). Conclusions This study highlights the potentially curative role of allo-HCT in MPN-U and provides clinicians with robust engraftment, GVHD and outcome data. Both engraftment and OS rates appear acceptable yet NRM and CIR rates in both settings remain high and need to be addressed. The impact of abnormal karyotype at the time of allo-HCT and a trend towards higher risks of relapse requires further elucidation. Disclosures McLornan: Novartis: Honoraria; Jazz Pharmaceuticals: Honoraria, Speakers Bureau. Robin:Novartis Neovii: Research Funding. Chalandon:Novartis: Consultancy, Honoraria; Bristol-Myers Squibb: Consultancy, Honoraria; Pfizer: Consultancy, Honoraria; Incyte Biosciences: Consultancy, Honoraria. Beelen:Medac GmbH Wedel Germany: Consultancy, Honoraria. Kröger:Sanofi-Aventis: Honoraria; Riemser: Research Funding; Novartis: Honoraria, Research Funding; Neovii: Honoraria, Research Funding; Medac: Honoraria; JAZZ: Honoraria; DKMS: Research Funding; Celgene: Honoraria, Research Funding. Milojkovic:Novartis: Honoraria, Speakers Bureau; Incyte: Honoraria, Speakers Bureau; Pfizer: Honoraria, Speakers Bureau; BMS: Honoraria, Speakers Bureau. Hernandez Boluda:Incyte: Other: Travel expenses paid.