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International audience; BACKGROUND: Voriconazole (VRC), a widely used triazole antifungal, exhibits significant inter- and intra-individual pharmacokinetic variability. The main metabolite voriconazole N-oxide (NOX) can provide information on the patient’s drug metabolism capacity. OBJECTIVES: Our objectives were to implement routine measurement of NOX concentrations and to describe the metabolic ratio (MR), and the contribution of the MR to VRC therapeutic drug monitoring (TDM) by proposing a suggested dosage-adjustment algorithm. PATIENTS AND METHODS: Sixty-one patients treated with VRC were prospectively included in the study, and VRC and NOX levels were assayed by LC-MS/MS. A mixed logistic model on repeated measures was implemented to analyze risk factors for the patient’s concentration to be outside the therapeutic range. RESULTS: Based on 225 measurements, the median and interquartile range were 2.4 μg/mL (1.2; 4.2), 2.1 μg/mL (1.5; 3.0), and 1.0 (0.6; 1.9) for VRC, NOX, and the MR, respectively. VRC C(min) 1.15 and

Relapsed B-cell acute lymphoblastic leukemia (B-ALL) after allogeneic stem cell transplantation (allo-HCT) still represents a major concern with poor outcomes. The aim of this study is to compare the efficacy and safety of blinatumomab and donor lymphocyte infusion (DLI) versus blinatumomab alone in this setting. This is a multicenter retrospective study from centers of SFGM-TC. All transplanted patients who received blinatumomab salvage therapy were included. Patients who received DLI from 1 month before to 100 days after the starting of blinatumomab were included in the blina-DLI group. Seventy-two patients were included. Medium follow-up was 38 months. Fifty received blinatumomab alone and 22 the association blinatumomab-DLI. Two-year overall survival (OS) was 31% in the blinatumomab group and 43% in the blinatumomab-DLI group (p=0.31). Studying DLI as a time dependent variable, PFS did not significantly differ between the 2 groups (HR:0.7, 95%CI:0.4-1.5). In multivariate analysis, DLI was not a prognostic factor for OS, progression-free survival and progression/relapse incidence. Adverse events and graft-versus-disease rates were comparable in the 2 groups. In conclusion, adding DLI between 1 month before and 100 days after start of blinatumomab is safe and does not seem to improve outcomes in B-ALL patients who relapsed after allo-HCT.

Early relapse (ER) following Autologous Hematopoietic Cell Transplantation (AHCT) confers a poor prognosis. We therefore developed a novel scoring system to predict ER. A total of 14,367 AHCT-1 patients were transplanted between 2014 and 2019, and were conditioned with Melphalan 200 mg/m2 (Mel200) (n = 7228; 2014–2017) (training cohort); Mel200 (n = 5616; 2018–2019) or Mel140 (n = 1523; 2018–2019) (validation cohorts). PFS-12 and the Cumulative Incidence of Relapse at 12 months were 84.1% and 14.7% (training Mel200), 87.2% and 11.6% (validation Mel200), and 80.3% and 16.9% (validation Mel140), respectively. The points in the risk score were: 0, 1,2 for ISS stages I, II, and III; Disease status: 0 (CR/VGPR); 1 (PR); 2 (SD/MR); 4 (Relapse/Progression); and 1 for Karnofsky ≤ 70. The distribution of scores: 0 (24%), 1 (33.9%), 2 (29.6 %), 3 (9.5%), and ≥4 (2.7%). The score separated PFS-12, with the lowest risk group (n = 1752) having a PFS-12 of 91.7% and the highest risk group (n = 195) 57.1%. This also applied in cytogenetically high-risk patients. If the pre-score baseline risks are 15% (standard risk) and 25% (high-risk), a score of ≥4 confers calculated risks of 38% and 54%, respectively. This novel EBMT ER score, therefore, allows for the identification of five discrete prognostic groups.

Allogeneic hematopoietic stem cell transplantation remains the best curative option for higher-risk myelodysplastic syndrome. The presence of monosomal karyotype and/or complex karyotype abnormalities predicts inferior survival after allo-SCT in MDS patients. Haploidentical allo-SCT has been increasingly used in acute leukemia (AL) and has similar results as using HLA-matched donors, but data on higher-risk MDS is sparse. We compared outcomes in 266 patients with higher-risk MDS after HLA-matched sibling donor (MSD, n = 79), HLA-matched unrelated donor (MUD, n = 139) and HLA haploidentical donor (HID, n = 48) from 2010 to 2019. Median donor age differed between the three groups (p p = 0.014). This observation could be explained by a higher progression-free survival with MUD (p = 0.014). The cumulative incidence of grade 2–4 acute GvHD was significantly higher in the HID group (p = 0.051). However, in multivariable analysis, patients transplanted using an HID had comparable mortality to patients transplanted using a MUD (subdistribution hazard ratio [sHR]: 0.58 [0.32–1.07]; p = 0.080) and a MSD ([sHR]: 0.56 [0.28–1.11]; p = 0.094). MUD do not remain a significant positive predictor of survival, suggesting that beyond the donor-recipient HLA matching, the donor age might impact recipient outcome.

We report the results from a multicentre retrospective study of 220 adult patients who underwent allogeneic hematopoietic stem cell transplantation (alloHSCT) for therapy-related acute myeloid leukemia (t-AML). Median age at t-AML diagnosis was 56 years, with a prior history of haematological (45%) or gynaecological neoplasia (37%). Median time from cytotoxic exposure to t-AML diagnosis was 54.7 months. At transplant, around 20% of patients had measurable residual disease and 3% of patients were not in complete remission. The median follow-up was 21.4 months (Q1-Q3, 5.9–52.8). At 12 months, overall survival (OS), event-free survival (EFS), and graft-versus-host-disease (GVHD)-free-relapse-free survival (GRFS) were 60.7% (95% CI 54.6–67.5), 52.8% (95% CI 46.5–68.4), and 44.1% (95% CI 37.6–51.8), respectively. At 5 years, OS, EFS, and GRFS were 44.1% (95% CI 37.4–52.1), 40.4% (95% CI 33.9–48.1), and 35.3% (95% CI 28.8–43.3), respectively. At last follow-up, 44% of patients were in complete remission (n = 96) and transplant-related mortality accounted for 39% of all deaths (n = 119). Multivariable analysis revealed that uncontrolled t-AML at transplant was associated with lower EFS (HR 1.94, 95% CI 1.0-3.7, p = 0.041). In conclusion, alloHSCT for t-AML shows encouraging results and offers additional opportunity with the emergence of novel pre-graft therapies.

Chimeric antigen receptor (CAR) T cells are a new class of anti-cancer therapy that involves manipulating autologous or allogeneic T cells to express a CAR directed against a membrane antigen. In Europe, tisagenlecleucel (Kymriah™) has marketing authorization for the treatment of relapsed / refractory acute lymphoblastic leukemia (ALL) in children and young adults, in addition to the treatment of relapsed/refractory diffuse large B-cell lymphoma (DLBCL); the marketing authorization for axicabtagene ciloleucel (Yescarta™) is for the treatment of relapsed / refractory high-grade B-cell lymphoma and for the treatment of primary mediastinal B-cell lymphoma. Both cell products are genetically modified autologous T cells directed against CD19. These recommendations, drawn up by a working group of the Francophone Society of Bone Marrow transplantation and cellular Therapy (SFGM-TC) relate to the management of patients and the supply chain: medium-term complications, in particular cytopenias and B-cell aplasia, nursing and psychological supportive care. In another work, we will address long-term monitoring, post-marketing authorization pharmacovigilance and issues relating to JACIE and regulatory authorities. These recommendations are not prescriptive; their aim is to provide guidelines for the use of this new therapeutic approach. The purpose of this workshop is to outline the organizational aspects of this new therapeutic approach.

International audience; Several scoring systems have been developed to assess suitability of individual patients for intensive acute myeloid leukemia (AML) therapy. We sought to compare the performance of these scores in a cohort of 428 consecutive adults with AML who received conventional induction chemotherapy in five academic centers in France. All scoring systems identified a subset of patients with increased 28 and 56-day mortality although the prediction accuracy was overall limited with C-statistics of ranging from 0.61 to 0.71 Overall survival (OS) prediction was more limited and restricted to scoring systems that include AML-related parameters. The outcome of 104 patients (24%) considered unsuitable for intensive chemotherapy based on criteria used in recent randomized trials was similar to that of the other 324 patients (28-day mortality, odds ratio [OR] = 1.88, P = 0.2; 56-day mortality, OR = 1.71, P = 0.21; event-free survival, hazard ratio [HR] = 1.08, P = 0.6; OS, HR = 1.25, P = 0.14) with low discrimination (C-statistic: 0.57, 0.56, 0.50, and 0.52 for 28-day, 56-day mortality, EFS, and OS, respectively). Together, our findings indicate that the accuracy of currently available approaches to identify patients at increased risk of early mortality and shortened survival after intensive AML therapy is relatively limited. Caution regarding the use of available scoring systems should be warranted in clinical decision-making.

Microtransplantation (MT) is based on injection of HLA-mismatched G-CSF mobilized hematopoietic stem cells, in combination with chemotherapy but without use of conditioning regimen nor immunosuppressive drugs. As a result, a transient microchimerism is induced without engraftment. Its efficacy relies both on host immune system stimulation (recipient versus tumor) and on a graft versus tumor effect. Data are scarce and concern mostly Asian patients with acute myeloid leukemia (AML) and high risk myelodysplastic syndrome (HR-MDS). In comparison to conventional treatment without MT, higher complete remission rates and longer disease free survival and overall survival have been reported. Safety seems acceptable. The most frequent adverse event is non-severe cytokine release syndrome. Risk of GVHD remains very low. Here, we summarize the published data and detail the practical aspects of the procedure. Current data are not strong enough to provide recommendations on indications. Nevertheless, it seems reasonable to propose MT to patients with AML or HR-MDS, regardless of age, presenting an indication for allogeneic stem cell transplantation but ineligible for it. MT is still under investigation and rather be proposed within clinical trials.

Introduction: Cellular composition of grafts is believed to be one of the significant determinants of outcomes of reduced-intensity conditioning (RIC) allogenic hematopoietic cell transplantation (allo-HCT). However, inconsistent results of the influence of CD34+ cells dose on the incidence of graft-versus-host disease (GVHD), disease control and survival have been reported in studies published thus far. Allo-HCT remains the only potentially curative treatment modality for eligible patients with myelofibrosis (MF). As patients with this diagnosis were underrepresented or not included in the above mentioned analyses, this EBMT registry study aimed to determine impact of CD34+ cell counts on allo-HCT results in this population. Methods: Six hundred and fifty seven patients with primary or secondary MF transplanted with use of peripheral blood (PB) as a source of stem cells after RIC regimen (Fludarabine/Melphalan, N=536 (82%); Fludarabine/Busulphan, N=121 (18%)) between 2000 and 2016 were included. Stem cell donor type was HLA-identical sibling (MSD; N=249, 38%) or unrelated (UD; N=408, 62%). Use of ex vivo T-cell depletion and post-transplant cyclophosphamide to prevent GVHD were the exclusion criteria. Median patient age was 58 (range, 22-76) years. In-vivo T-cell depletion was used in 526 (80%) of cases. Median transplanted CD34+ dose was 6.6 (2-29) x 10^6 per kg of recipient body weight. Median follow-up was 46 (2-194) months. Patient and transplant characteristics are summarized in Table 1. Results: We did not observe any impact of CD34+ cells dose on outcome variables in the whole study group. However, in an analysis adjusted for donor type, among patients transplanted from a MSD, the 2yr overall survival (OS) probability was 77% for those transplanted with higher doses of CD34+ cells (defined as >7.0 x 10^6/kg) compared to 60% for lower CD34+ counts (below 7.0 x 10^6/kg), P=0.007 (Figure 1). The corresponding probabilities of 2yr non-relapse mortality (NRM) were 16% and 29% (P=0.04), respectively (Figure 2). In multivariate analysis, for patients transplanted from a MSD, higher CD34+ dose was an independent predictor for better survival (HR 0.56; P=0.01) and lower risk of NRM (HR 0.54; P=0.02). We did not find any association between CD34+ counts with probability of engraftment, the incidence of acute (aGVHD) and chronic (cGVHD) nor disease relapse. The effect of cell dose was not seen in the UD cohort. Factors associated independently with an unfavorable outcome in the whole study group were: older patient age and transplantation from CMV seronegative donors to seropositive recipients for OS and NRM and use of an UD and female donor for NRM. Allo-HCT from UD was also an independent predictor for higher incidence of aGVHD and lower probability of engraftment. Use of in vivo T-cell depletion was a protective factor for aGVHD. It was in turn associated with higher risk of relapse. Conclusions: Our analysis suggests a potential survival benefit for MF patients treated with RIC PB-allo-HCT from MSD with higher doses of CD34+ cells (threshold > 7.0 x 10^6/kg). We suggest that this factor should be taken into consideration when planning and performing hematopoietic cell apheresis. Disclosures Kröger: Celgene: Honoraria, Research Funding; DKMS: Research Funding; JAZZ: Honoraria; Medac: Honoraria; Neovii: Honoraria, Research Funding; Novartis: Honoraria, Research Funding; Riemser: Research Funding; Sanofi-Aventis: Research Funding. Robin:Novartis Neovii: Research Funding. Chevallier:Daiichi Sankyo: Honoraria; Jazz Pharmaceuticals: Honoraria; Incyte: Consultancy, Honoraria. Mielke:Bellicum: Consultancy, Honoraria, Other: Travel (via institution); EBMT/EHA: Other: Travel support; Miltenyi: Consultancy, Honoraria, Other: Travel and speakers fee (via institution), Speakers Bureau; IACH: Other: Travel support; Jazz Pharma: Honoraria, Other: Travel support, Speakers Bureau; ISCT: Other: Travel support; GILEAD: Consultancy, Honoraria, Other: travel (via institution), Speakers Bureau; Celgene: Honoraria, Other: Travel support (via institution), Speakers Bureau; DGHO: Other: Travel support; Kiadis Pharma: Consultancy, Honoraria, Other: Travel support (via institution), Speakers Bureau. Snowden:Janssen: Honoraria; Mallinckrodt: Honoraria; Kiadis: Membership on an entity's Board of Directors or advisory committees; IDMC: Honoraria; Jazz: Honoraria; Gilead: Honoraria. Blaise:Sanofi: Honoraria; Pierre Fabre medicaments: Honoraria; Molmed: Consultancy, Honoraria; Jazz Pharmaceuticals: Honoraria. Hernandez Boluda:Incyte: Other: Travel expenses paid. McLornan:Jazz Pharmaceuticals: Honoraria, Speakers Bureau; Novartis: Honoraria.

International audience; Introduction Acute graft-versus-host disease (aGvHD) is a major source of mortality following allogeneic hematopoietic cell transplantation (allo-HCT). Standard 1st line therapy for the treatment of aGvHD involves corticosteroids (CS). However, more than 50% of patients are refractory to CS (SR-aGvHD) and the associated mortality rate is of up to 80%. Recently, Ruxolitinib has been approved as 2nd line treatment for SR-aGvHD. However, patients with severe gastrointestinal (GI) aGvHD seem less likely to respond to Ruxolitinib and have poor outcomes with limited therapeutic options.In this context, fecal microbiotherapy has shown promising results in several pilot studies in patients with refractory GI-aGvHD. Here we report clinical outcomes from 81 patients diagnosed with SR or dependent (SD) GI-aGvHD treated with the pooled allogeneic microbiotherapy MaaT013 as part of the Early Access Program (EAP) in France.Methods 81 patients with SR/SD GI-aGvHD (Classical n=62, late onset n=12, overlap syndrome n=7) were treated with MaaT013 as part of an EAP in France. These patients had failed 1 to 6 prior systemic GvHD treatment lines (median 2; 66/81 received Ruxolitinib). Most patients had grade III-IV aGvHD (11% grade II, 51% grade III, 38% grade IV).For each patient, a total of 3 MaaT013 administrations were planned every 7 +/- 2 days. Each dose comprised 30g of feces in 150 mL of diluent, from 4 to 8 healthy donors, administered by enema (except for 1 patient by nasogastric tube).Treatment response was calculated among all treated patients based on aGvHD staging and grading at day 28 (D28) at the time of the EAP request.Results At D28, the GI-overall response rate (ORR) was 56%: 30 complete response (CR, 37%), 11 very good response rate (VGPR, 14%), 4 partial response (PR, 5%). The GI-ORR was higher in patients with lower grade aGvHD (89% in grade II, 66% in grade III, 32% in grade IV) and higher in SD versus SR patients (92% versus 49%). Including skin and liver symptoms (n=78), response rate was 49%, including 24 CR, 11 VGPR and 3 PR and inversely correlated with aGvHD initial grade (88% in grade II, 55% in grade III, 30% in grade IV).Overall survival (OS) was 51% at 6 months (M6) and 39% at M12. The median follow-up among surviving patients was 355 days (range, 53-731). OS was significantly higher in patients achieving at least GI-PR at D28 (Responder, R; n=45) compared to patients in treatment failure (Non-responder, NR; n=35): 69% versus 28% at M6, 59% versus 14% at M12, respectively. Median survival duration in R was 451 days versus 32 days in NR.Interestingly, aGvHD response was improved in the subgroup of 31 patients previously treated with Ruxolitinib as 2nd line and MaaT013 as 3rd line (65% D28 GI-ORR, OS M6 55% and 49% M12 and 74% versus 15% at M6 and 74% versus 0% at M12 for R and NR respectively).MaaT013 displayed a good overall safety profile in the EAP population: 20 pharmacovigilance cases were reported in 18 patients: sepsis in 11 patients, C. difficile colitis in 2, E. coli osteoarthritis in 1, G. silvicola in stools from 1, P. aeruginosa sinusitis in 1, appearance of air bubbles in the mesorectum in 1, respiratory distress in 1. No pathogen transmission was reported. In 2 patients, non-pathogenic commensal bacteria isolated following infectious events were detected in the administered MaaT013 batch. Causality could not be formally excluded in these cases.The overall incidence of bacteremia (14%) remains low, compared to an incidence of 31% to 74% in bloodstream infections reported in patients with GI-aGvHD. This suggests that fecal microbiotherapy may have a protective effect on bacterial translocation, but this needs to be confirmed in further clinical trials.47 deaths have been reported; the cause of which was GvHD in 21 patients, severe infection in 13, relapse of underlying malignancy in 6, COVID-19 in 3, hemorrhage during surgery in 1, neurological complications post allo-HCT in 1, and cardiac arrest in 2 patients. No causality link with MaaT013 administration has been identified.Conclusion Overall, EAP clinical data showed that MaaT013 was safe and effective for the treatment of SR/SD-GI-aGvHD especially in patients having previously received ruxolitinib. Interestingly, GI-response to aGvHD correlates with increased OS, suggesting a strong favorable benefit-risk profile for MaaT013. A Phase 3 trial is currently ongoing to confirm these results in ruxolitinib-refractory patients (NCT04769895).

The role of spleen size and splenectomy for the prediction of post-allogeneic hematopoietic stem cell transplant (allo-HCT) outcome in myelofibrosis remains under debate. In EBMT registry, we identified a cohort of 1195 myelofibrosis patients transplanted between 2000-2017 after either fludarabine-busulfan or fludarabine-melphalan regimens. Overall, splenectomy was performed in 202 (16.9%) patients and its use decreased over time (28.3% in 2000-2009 vs 14.1% in 2010-2017 period). By multivariate analysis, splenectomy was associated with less NRM (HR 0.64, 95% CI 0.44-0.93, P = .018) but increased risk of relapse (HR 1.43, 95% CI 1.01- 2.02, P = .042), with no significant impact on OS (HR 0.86, 95% CI 0.67-1.12, P = .274). However, in subset analysis comparing the impact of splenectomy vs specific spleen sizes, for patients with progressive disease, an improved survival was seen in splenectomised subjects compared to those patients with a palpable spleen length ≥ 15 cm (HR 0.44, 95% CI 0.28-0.69, P < .001), caused by a significant reduction in NRM (HR 0.26, 95% CI 0.14- 0.49, P < .001), without significantly increased relapse risk (HR 1.47, 95% CI 0.87-2.49, P = .147). Overall, despite the possible biases typical of retrospective cohorts, this study highlights the potential detrimental effect of massive splenomegaly in transplant outcome and supports the role of splenectomy for myelofibrosis patients with progressive disease and large splenomegaly.

Chimeric antigen receptor (CAR) T cells are a new class of anti-cancer therapy that involves manipulating autologous or allogeneic T cells to express a CAR directed against a membrane antigen. In Europe, tisagenlecleucel (Kymriah™) has marketing authorization for the treatment of relapsed / refractory acute lymphoblastic leukemia (ALL) in children and young adults, in addition to the treatment of relapsed/refractory diffuse large B-cell lymphoma (DLBCL); the marketing authorization for axicabtagene ciloleucel (Yescarta™) is for the treatment of relapsed / refractory high-grade B-cell lymphoma and for the treatment of primary mediastinal B-cell lymphoma. Both cell products are genetically modified autologous T cells directed against CD19. These recommendations, drawn up by a working group of the Francophone Society of Bone Marrow transplantation and cellular Therapy (SFGM-TC) relate to the management of patients and the supply chain: medium-term complications, in particular cytopenias and B-cell aplasia, nursing and psychological supportive care. In another work, we will address long-term monitoring, post-marketing authorization pharmacovigilance and issues relating to JACIE and regulatory authorities. These recommendations are not prescriptive; their aim is to provide guidelines for the use of this new therapeutic approach. The purpose of this workshop is to outline the organizational aspects of this new therapeutic approach.

International audience; The Francophone Society of Bone Marrow Transplantation and Cellular Therapy (SFGM-TC) organizes annual workshops in the attempt to harmonize clinical practices among different francophone transplantation centers. Here, we report our recommendations regarding the prophylaxis of cytomegalovirus (CMV), herpes simplex virus (HSV), varicella zoster virus (VZV) and hepatitis B virus infection after allogeneic hematopoietic cell transplantation in adult patients.

International audience; The Francophone Society of Bone Marrow Transplantation and Cellular Therapy (SFGM-TC) organizes annual workshops in the attempt to harmonize clinical practices among different francophone transplantation centers. Here we report our recommendations regarding detection of the multidrug-resistant bacteria in hematology.

Rationale and Aim: In patients with Myeloma, early relapse following Autologous Haematopoietic Cell Transplantation (Auto-HCT) is a poor prognostic marker. Two groups have published scoring systems to predict early relapse. The CIBMTR score is based on cytogenetics, the bone marrow plasma cell percentage at the time of Auto-HCT and serum albumin. The GIMEMA Simplified early relapse in multiple myeloma (S-ERMM) score is a cumulative score based on a raised serum lactate dehydrogenase (LDH), t(4;14), del17p, low albumin, bone marrow plasma percentage >60%, and lambda light chain. The aim of the current study was to develop a scoring system to predict early relapse post-Auto-HSCT-1 using readily available variables. Study design and statistics: Within the EBMT database, there were 8,206 patients meeting the following eligibility criteria: First auto transplant 2014-2019, Known sex, ISS at diagnosis, cytogenetics analysis at diagnosis, disease status at Auto-HCT, Interval diagnosis-Auto-HCT > 1 month and Results: Comparison of the training and validation cohorts revealed no relevant differences (Table 1). Importantly, OS and PFS of both cohorts were overlapping with the probability of PFS at 12 months being 83.3% and 86.8%, respectively. The cumulative incidence of relapse at 12 month was 15.7% and 12.1%, respectively. Among patients who relapsed early, this occurred at a median of 6.64 months (0.56-11.99) in the first cohort, and at 5.85 months (0.1- 11.99) in the second cohort. The final model included (1) disease status at Auto-HCT, (2) age at Auto-HCT, and (3) ISS at diagnosis. Considering the order of magnitude of the coefficients, the points attributed in the risk score were: 0 for CR or VGPR; 1 for PR or SD/MR; 3 for Rel/Prog; 0 / 1/ 2 respectively for ISS I / II / III and -1 for Age=75 yrs. The Hazard Ratio for a +1 point is 1.52 i.e. the risk of early relapse/death increased on average by 52% for each additional point in the score. The distribution of risk scores was as follows: Score= -2 (n=757), -1 (n=1,481), 0 (n=1,358), 1 (n=647), and 2 (n=146). The score allows separation of the PFS12 curves (Figure 1), with the lowest risk group (N=757) having a PFS at 12 months of 91%, and the highest risk group (N=146) having a PFS at 12 months of 65%. Despite some minor differences in the risk factors between the training and validation cohorts, the score has a similar average effect (HR=1.48 i.e. + 48% hazard for each additional point) and worked well in separating the curves, in particular in identifying the patients at high risk of early relapse. Discussion and conclusion: The new EBMT score to predict early relapse post-Auto-HCT uses the easily available variables of age and ISS stage at diagnosis as well as the dynamic variable of response to induction. With this simple approach, we were able to clearly identify patients at high risk of early relapse. To our surprise, older age emerged as a protective factor against relapse. This may reflect a relative selection bias in that older patients with higher risk disease may not have been selected for transplant. Impact of cytogenetics will be presented at the Congress. In conclusion, this novel scoring system is robust and easy to use in routine daily practice. Figure 1 Figure 1. Disclosures Beksac: Amgen: Consultancy, Speakers Bureau; Janssen: Consultancy, Speakers Bureau; Celgene: Consultancy, Speakers Bureau; Sanofi: Consultancy, Speakers Bureau; Takeda: Consultancy, Speakers Bureau; Oncopeptides: Consultancy. Blaise: Jazz Pharmaceuticals: Honoraria. Leleu: Karyopharm Therapeutics: Honoraria; AbbVie: Honoraria; Bristol-Myers Squibb: Honoraria; Amgen: Honoraria; Merck: Honoraria; Mundipharma: Honoraria; Novartis: Honoraria; Carsgen Therapeutics Ltd: Honoraria; Oncopeptides: Honoraria; Janssen-Cilag: Honoraria; Gilead Sciences: Honoraria; Celgene: Honoraria; Pierre Fabre: Honoraria; Roche: Honoraria; Sanofi: Honoraria; Takeda: Honoraria, Other: Non-financial support. Forcade: Novartis: Consultancy, Other: Travel Support, Speakers Bureau; Gilead: Other: Travel Support, Speakers Bureau; Jazz: Other: Travel Support, Speakers Bureau; MSD: Other: Travel Support. Rabin: Janssen: Consultancy, Honoraria, Other: Travel support for meetings; BMS / Celgene: Consultancy, Honoraria, Other: Travel support for meetings; Takeda: Consultancy, Honoraria, Other: Travel support for meetings. Kobbe: Celgene: Research Funding. Sossa: Amgen: Research Funding. Hayden: Jansen, Takeda: Other: Travel, Accomodation, Expenses; Amgen: Honoraria. Schoenland: Pfizer: Honoraria; sanofi: Research Funding; janssen,Prothena,Takeda,: Consultancy, Honoraria. Yakoub-Agha: Jazz Pharmaceuticals: Honoraria.

Introduction Anemia is a common complication of hematological chemotherapy for acute leukemia and following hematopoietic stem cell transplantation (HSCT). Exposure to allogeneic blood transfusions has been associated with unfavorable outcome in several studies in a non-surgical settings. Retrospective studies in hematological intensive unit have suggested that single red blood cell (RBC) unit transfusion policy may reduce the number of RBC used in comparison with a classical double RBC unit transfusion policy, without clinical impact. The aim of the study was to demonstrate that single RBC transfusion was non inferior to the standard double RBC transfusion arm in terms of severe complication or mortality for inpatient with hematological malignancies. Key secondary endpoint, was the comparison of the numbers of RBC units transfused in each arm. Method In a phase 3 multicenter randomized trial, 245 adults' patients with acute leukemia requiring intensive chemotherapy or patients receiving autologous or allogeneic HSCT were randomly assigned (1:1) to receive either single RBC unit (1 RBC arm, n=125) per transfusion or double RBC (2 RBC arm, n=120) per transfusion when hemoglobin level was below 8g/dL. The primary composite endpoint was the percentage of patients who developed a grade ≥3 complications defined as stroke, transient ischemic attack, acute coronary syndrome, heart failure, elevated troponin level, intensive care unit transfer, death, new pulmonary infiltrates, and/or transfusion-related infections during hospital stays. The secondary endpoint was the number of red cell units transfused per patient per hospital stay. The primary endpoint was compared between groups by non-inferiority analysis for the proportion risk difference using Farrington-Manning method with a non-inferiority margin of 0.1, in ITT dataset. Results Hematological disease were as followed: AML (59%), ALL (13.1%), Lymphoma (16.4%), others (11.5%). The median age was 55 years. Baseline characteristics were well balanced between the 2 arms (Figure 1A). A total of 981 and 592 transfusions have been necessary in the 1 RBC arm and 2 RBC arm, respectively. The median of RBC unit per transfusion was 1(1-1) and 2(2-2) in the 1 RBC and 2 RBC arm, respectively. The mean pre transfusion hemoglobin level was 7.49 +/- 0.83 g/dL in the 1 RBC arm and 7.46 +/- 0.67 g/dL in the 2 RBC arm (p=0.275). Hemoglobin level at discharge was 9.35 +/-1.14 g/dL in the 1 RBC arm and 9.58 +/-1.13 g/dL in the 2 RBC arm (p=0.118). The median (IQR) of red-cell units transfused per patient was 7 (4-12) in the single arm and 8 (4-12) in the double arm (p=0.65). The median number of platelet transfusion event was 7 (3.5-11.5) in the 1 RBC arm and 7 (3-13) in the 2 RBC arm (p=0.69). The median (IQR) number of red cell unit transfused per cycle and per day was 7 (3-9) and 0.28 (0.17-0.37) in the 1RBC arm and 6 (4-10) and 0.27 (0.20-0.38) in the 2 RBC arm (p=0.61 and p=0.47). The predefined non-inferiority criteria was achieved with 28 patients developing a serious complication in the 1 CGR arm (22.4%) and 28 patients in the 2 RBC arm (23.3%) (Risk difference 0.009; 95% Confidence interval [-0.0791- 0.0978] (Figure 1B). Conclusion: Single RBC transfusion policy is non inferior to double RBC transfusion policy in hematological intensive care unit for patient receiving a bone marrow transplant or intensive chemotherapy. Single RBC unit transfusion can be used safely in daily clinical practice. The single RBC transfusion policy does not reduce the number of RBC transfusion. Figure 1 Figure 1. Disclosures Jardin: Genexpath: Patents & Royalties: The author is a potential inventor on a patent application for the LymphoSign, which has been licensed for by Genexpath Patents & Royalties. .

Background Post-transplant cyclophosphamide (PTCy) is a powerful strategy to prevent occurrence of graft-versus-host disease (GvHD) following allogeneic hematopoietic stem cell transplantation (HSCT). Initially developed in the setting of haploidentical HSCT, PTCy has been increasingly used for fully HLA-matched transplants with favorable results. The purpose of this retrospective multi-center study is to evaluate PTCy-based GvHD prevention for patients with acute leukemia receiving a traditionally prohibitive highly mismatched HSCT and to describe their outcome. Methods This is a registry-based study employing the data set of the Acute Leukemia Working Party (ALWP) of the European Society of Blood and Marrow Transplantation (EBMT). We retrospectively assessed the outcome of adult patients with acute myeloid or lymphoblastic leukemia (AML/ALL), transplanted between 2010 and 2020 with grafts from HLA-mismatched donors with more than 5/10 mismatches using PTCy-based GvHD prophylaxis. Results The study cohort consisted of 59 patients, with a median time of follow up of 20 (95% CI, 14-39) months. The median age was 47 (range, 18-69) years. Forty-four patients had a diagnosis of AML, 14 of ALL and one case of mixed phenotype acute leukemia. At time of transplant, 39 (66%) were in first or second complete remission, 4 (7%) were in later remission and 16 (27%) had active, relapsed or refractory, disease. Conditioning regimens were myeloablative for 54% of cases and peripheral blood was the preferred source of stem cells (64%). All donors were related. Most patients (85%) received a 4/10 HLA-matched transplant, the most commonly mismatched loci were C and DQB1, often with a double mismatch involving the same locus. Two cases of fully mismatched donors were also recorded. PTCy was always associated with other immunosuppressive treatments, especially with the standard combination of calcineurin inhibitors and mycophenolate mofetil. In only 8 cases in vivo T-cell depletion was realized with anti-thymocyte globulin. A large proportion of patients (86%) attained engraftment with a median time of 19 (range, 11-37) days. Only 8 patients did not reach engraftment and all of them died of infection or disease relapse in the first one-hundred days (range, 6-99) after HSCT. Thirty-three patients (58%) did not present any sign of acute GvHD (aGvHD). Cumulative incidence of grade II-IV and grade III-IV aGvHD at day 180 were 30.3% and 14.3%, respectively. At 2 years, the cumulative incidence of chronic GvHD (cGvHD) was 21%, and 7% for extensive cGvHD. Twenty-four patients died during the study period, mostly because of leukemia progression (n=13, 54%), infectious complications (n=6, 25%) and interstitial pneumonia (n=2, 8%). Other causes of death were hemorrhage, GvHD, and another non HSCT-related that accounted for one case (4%) each. At 2 years, the overall survival (OS), leukemia-free survival (LFS), and a GVHD and relapse free survival (GRFS) were 56%, 54% and 47% respectively. Rates of relapse incidence and non-relapse mortality were 28% and 19%, respectively. Conclusion According to this preliminary data overview, transplantation in a highly mismatched framework is possible, without unfavorable OS, LFS and GVHD rates. Despite the important limitation of the retrospective non-controlled nature of this analysis, these findings suggest that PTCy-based strategies could help overcome the barrier of HLA-matching and configure a new setting of transplantation, encouraging more in-depth investigations. Figure 1 Figure 1. Disclosures Labopin: Jazz Pharmaceuticals: Honoraria. Angelucci: Novartis: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Celgene BSM: Honoraria, Other: DMC; Blue Bird Bio: Honoraria, Membership on an entity's Board of Directors or advisory committees; Menarini-Stemline: Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: steering commitee, Speakers Bureau; Vertex Pharmaceuticals: Honoraria, Other: DMC; Crispr therapeutics: Honoraria, Other: DMC; Glaxo: Honoraria, Membership on an entity's Board of Directors or advisory committees; Gilead: Honoraria, Membership on an entity's Board of Directors or advisory committees. Yakoub-Agha: Jazz Pharmaceuticals: Honoraria. Mohty: Takeda: Honoraria; Jazz: Honoraria, Research Funding; Gilead: Honoraria; Adaptive Biotechnologies: Honoraria; Sanofi: Honoraria, Research Funding; Pfizer: Honoraria; Novartis: Honoraria; Janssen: Honoraria, Research Funding; Celgene: Honoraria, Research Funding; Bristol Myers Squibb: Honoraria; Amgen: Honoraria; Astellas: Honoraria.

Introduction Allogeneic Hematopoietic Cell Transplantation (allo-HCT) has proved its efficiency in reducing Acute Myeloid Leukemia (AML) recurrence, although it was associated with high rates of complications especially in older patients. The worldwide number of allo-HCT has increased within 35 years, from 10.000 transplantations before 1985 to over a million in 2012. The decision to perform transplantation depends on the estimated risk-benefit ratio. High-risk prognostic factors include cytogenetics, age at diagnosis, presence of comorbidities and the response to treatment. By using combination of risk factors, international recommendations have been published to harmonize AML care and maximize the benefit of using allo-HCT. The principal aim of this study is to describe real life AML care management in all consecutive patients diagnosed and registered on 3 regional cancer registries in France, to analyze their outcome after different therapeutic strategies, following or not the international recommendations. Method This retrospective study included all AML patients diagnosed between January 2012 and December 2016 reported to the French population data-based of regional cancer registries specialized in hematological malignancies. Allo-HCT data were extracted from the Société Française de Greffe de Moelle et de Thérapie Cellulaire (SFGM-TC) registry. Two groups of patients were defined according to the treatment received: i) group 1, patients who have received the best recommended care including allo-HCT considering HLA compatibility and best donor choice or best conventional treatment according to therapeutic guidelines based on individuals and clinical characteristics from The American Society for Blood and Marrow Transplantation guidance; ii) group 2, patients who received a treatment outside the recommendations. To study the impact of therapeutic decision on overall survival, a case-control study was performed using a one for one matching between group 1 and group 2. An exact matching on individual and disease characteristics (cytogenetic risk, Charlson score class, age group at diagnosis, subtype AML and response to treatment) allowed to pair-match patients following or not the international recommendations for therapeutic strategy. Net survival was estimated until five-year using non-parametric Pohar-Perme estimator (survival distribution compared using Grafféo test). Results A total of 1039 AML patients diagnosed from 2012 to 2016 were identified, 449 (43 %) received a curative treatment and 540 patients a non-curative treatment (hypomethylating agents, low dose of cytarabine or other palliative treatment, best supportive care combined to no effective treatment). Based on available clinical data, 430 patients were included in the study. Group 1 included 296 patients (68%), 167 males and 129 females with 54 receiving allo-HCT (32 geno-identical and 22 unrelated). Group 2 included 134 patients (31%), 72 males and 62 females with 94 receiving allo-HCT (14 geno-identical, 50 unrelated and 30 mismatched). In patients for whom allo-HCT represented the best option according to the recommendations (Figure B, n = 44), a very significant lower survival was observed in patients who did not receive allo-HCT when they were compared to patients who received allo-HCT, with a 5 year-overall survival probability of 7 % and 50 % respectively (p= 0.019). In patients for whom allo-HCT was not recommended (Figure A, n = 42), we did not observe any significant difference of survival between patients transplanted or not. Conclusion This analysis shows the importance of allo-HCT decision in AML patients, especially when following international guidelines. Although individual risks factors have been previously studied, our analysis sums up theses factors and allow to understand the importance of integrating allo-HCT in the therapeutic strategy of AML and to re-evaluate current practices and its impact on patient outcome. Figure 1 Figure 1. Disclosures Pigneux: Roche: Consultancy, Research Funding; BMS Celgene: Consultancy, Research Funding; Sunesis: Consultancy, Research Funding; Amgen: Consultancy; Novartis: Consultancy, Research Funding. Forcade: Novartis: Other: travel grant. Mohty: Pfizer: Honoraria; Novartis: Honoraria; Takeda: Honoraria; Jazz: Honoraria, Research Funding; Janssen: Honoraria, Research Funding; Gilead: Honoraria; Celgene: Honoraria, Research Funding; Bristol Myers Squibb: Honoraria; Astellas: Honoraria; Amgen: Honoraria; Sanofi: Honoraria, Research Funding; Adaptive Biotechnologies: Honoraria. Dulery: Novartis: Honoraria; Takeda: Consultancy; Gilead: Other: Travel support and registration fees for scientific meetings .

Rational: The significant increase in haplo-identical allogeneic cell transplantation (Allo-HCT) has led to the more frequent use of cyclophosphamide (Cy) after transplantation for graft-versus-host disease (GVHD) prophylaxis (PT-Cy). This strategy has subsequently been used in related and unrelated allogeneic HCT settings as well with some controversial results. Patients and Methods: We analyzed all consecutive Allo-HCTs from matched related (MR) and unrelated donors (HLA matched and mismatched: MUD and MMUD) reported to the SFGM-TC registry from January 2014 to December 2019 and who have received PT-Cy alone or in combination with other immunosuppressive molecules (IS). We therefore performed a pair-matched analysis (1/2) with transplantations using classic GVHD prophylaxis with (w) or without (wo) anti-thymocyte globulins (ATG). The primary objective was to evaluate the incidence and severity of acute and chronic GVHD in PT-Cy compared to other strategies. Secondary objectives included: modalities of PT-Cy and IS, cumulative incidence of relapse (CIR), non-relapse mortality (NRM), overall survival (OS), GVHD and relapse free-survival (GRFS), infection rates. Results: We analyzed a total of 1190 patients (pts), 386 (32%) received PT-Cy and matched with 804 (68%) pts who received classic GVHD prophylaxis (no PT-Cy). Among PT-Cy patients, 59% were males with a median age of 55.3 years (3.4-75.5), 49% were AML, 14% ALL, 20% MDS and MPS, 12.5% NHL and HL, and 4.5% Multiple Myeloma. Before transplantation, 61% of pts were in complete remission (CR), 34% not in CR, 2% in stable disease and 3% were not treated. Conditioning regimen was myeloablative in 35% of patients, 86% received peripheral blood stem cells, 31% were CMV negative pairs, 58% were sex-matched and 51% were ABO compatible. There was no significant difference between the PT-Cy and no PT-Cy groups regarding all the variables. We identified four groups: group 1: PT-Cy + IS (n=259), group 2: PT-Cy + ATG + IS (n=120), group 3: ATG w or wo IS (n=651) and group 4: other IS (n=160). We observed significant differences between the 4 groups for age (p The cumulative incidence of acute GVHD grades II, III/IV, chronic GVHD, relapse and NRM, the probability of OS and GRFS are shown in Table 1. The results of multivariate analysis (Table 2) showed a significant lower incidence of acute GVHD gr II, III, IV and chronic GVHD after PT-Cy + IS and a significant higher TRM after ATG ± IS. In addition, other well-known parameters were found to have a significant impact as age on OS and GRFS, use of unrelated donor on OS and CIR and PBSC on chronic GVHD. Regarding severe infections after HCT, there was no difference between PT-cy and pair-matched patients except for pneumonia (12.5% vs. 8% respectively, p=0.08) and septicemia (12% vs. 1.7% respectively, p In conclusion, there was a significant lower incidence and severity of acute and chronic GVHD in the PT-Cy group after related, HLA matched and mismatched unrelated Allo-HCT compared to matched patients with other GVHD prophylaxis with a higher NRM when patients received ATG. We did not observe significant translation into GRFS improvement probably due to the higher toxicity of PT-Cy. Figure 1 Figure 1. Disclosures Yakoub-Agha: Jazz Pharmaceuticals: Honoraria. Forcade: Novartis: Other: travel grant. Chalandon: Incyte, BMS, Pfizer, Abbie, MSD, Roche, Novartis, Gilead, Amgen, Jazz, Astra Zenec: Other: Travel EXpenses, Accomodation; Incyte: Speakers Bureau; Incyte, BMS, Pfizer, Abbie, MSD, Roche, Novartis, Amgen: Other: Advisory Board. Huynh: Jazz Pharmaceuticals: Honoraria. Dulery: Novartis: Honoraria; Takeda: Consultancy; Gilead: Other: Travel support and registration fees for scientific meetings .

Introduction Failure to respond to steroid therapy for intestinal acute graft-versus-host disease (aGvHD) is associated with limited further therapeutic options. Fecal microbiotherapy is defined as the perfusion of treated stool from one or several healthy donors via the upper or lower gastrointestinal (GI) route aiming at improving microbial diversity and functionality. Here we report clinical outcomes from a 76-patient cohort with steroid refractory (SR) GI-aGvHD treated with the pooled allogenic fecal microbiotherapeutic MaaT013. Twenty-four patients were treated in the prospective, single-arm, phase IIa, HERACLES study (NCT03359980) while 52 patients were treated in an expanded access program (EAP). Patients and methods For HERACLES, 24 patients with grade III-IV SR-GI-aGvHD were treated with MaaT013 in 26 European sites, as a 2 nd line therapy after SR diagnosis and evaluable for treatment response. In EAP, 52 patients with steroid-dependent or SR-GI-aGvHD (classical n=41, late onset n=3, overlap syndrome n=8) were treated. These patients had previously received and failed 1 to 6 lines (median 3; 40/52 received ruxolitinib) of GvHD systemic treatments. GI-GvHD response was evaluated weekly and 28 days after day (D) 0 (inclusion for HERACLES or 1st dose for EAP). For all patients, GI-overall response rate (ORR) at D28 was defined as the proportion of patients achieving complete response (CR), very good partial response (VGPR) or partial response (PR), compared to D0, without the use of additional systemic therapy. Other endpoints included the best overall response (BOR) achieved at any time, and overall survival (OS). Prepared under GMP, MaaT013 is characterized by a highly consistent richness of 455 ±3% OTUs and an Inverse Simpson index > 20. Treatment comprised 3 MaaT013 doses, each composed of 30 g of feces in 150 mL volume of inoculum (total 90 g of feces from 4 to 8 healthy donors) administered by enema (except for 2 EAP patients by nasogastric tube). All patients received at least 1 MaaT013 dose, 92% (HERACLES) and 87% (EAP) at least 2 doses, and 50% (HERACLES) and 71% (EAP) the full treatment course. In HERACLES, the reasons for not applying the 3 rd dose were death (n=5), physician decision to introduce salvage therapy (n=5), and ICU hospitalization (n=2)). Results In HERACLES, the GI-ORR was 38% including 5 CR, 2 VGPR and 2 PR. In EAP, positive GI-response was achieved in 31/52 patients (60% with 16 CR, 11 VGPR and 4 PR). Considering the GI-BOR, 13/24 (54%) and 35/52 (67%) achieved at least a PR in HERACLES and EAP respectively. In HERACLES, OS was 29% at month (M) 6 and 25% at M12. OS was significantly higher in responding (R) patients (achieving at least PR at D28) compared to non-responding (NR) (44% vs 20% at M6 and 44% vs 13% at M12, logrank p=0.047). In EAP, OS was 48% at M6 and 37% at M12, and significantly higher in R patients compared to NR (71% vs 17% at M6 and 62% vs 6% at M12, logrank p In HERACLES, treatment with MaaT013 was characterized by excellent tolerance: 252 Treatment-Emergent Adverse Events (TEAE) were reported for the 24 patients, the majority being infections (79%) and GI disorders (62%), as expected in GvHD patients. Of these 252 TEAE, only 2% (5 serious events in 2 patients) could not reasonably be excluded from being related to MaaT013 by the investigators. Shotgun sequencing in these 5 TEAE revealed that the causative infectious agents could not be detected in the administered MaaT013. In EAP, the safety profile of MaaT013 was considered satisfactory for all patients. 16S microbiome analyses were performed in the HERACLES population and showed that MaaT013 produced an early increase in α-diversity at genus level with a significant increase in Richness index at all evaluated timepoints (p Conclusion We herein report the treatment of 76 SR-GI-aGvHD patients using a full ecosystem, pooled-donor, high-richness biotherapeutic. The D28 GI-ORR was 38% and 60% in HERACLES and EAP respectively and this clinical benefit positively and significantly impacted OS (44% and 62% M12 in HERACLES and EAP R patients respectively). MaaT013 was shown to be safe and effective in these heavily immunocompromised patients, warranting further exploration of this approach. Figure 1 Figure 1. Disclosures Malard: JAZZ pharmaceuticals: Honoraria; Sanofi: Honoraria; Astellas: Honoraria; Biocodex: Honoraria; Therakos/Mallinckrodt: Honoraria; Janssen: Honoraria. Loschi: CELGENE/BMS: Honoraria; AbbVie: Ended employment in the past 24 months, Honoraria; Gilead: Ended employment in the past 24 months, Honoraria; Novartis: Ended employment in the past 24 months, Honoraria; Servier: Ended employment in the past 24 months, Honoraria; MSD: Honoraria. Cluzeau: Agios: Honoraria; Novartis: Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: travel, accommodations, expenses, Speakers Bureau; Roche: Consultancy, Honoraria; BMS/Celgene: Consultancy, Honoraria, Speakers Bureau; Jazz Pharma: Consultancy, Honoraria; Abbvie: Consultancy, Honoraria, Speakers Bureau; Amgen: Speakers Bureau; Pfizer: Other: travel, accommodations, expenses; Astellas: Speakers Bureau; Takeda: Other: travel, accommodations, expenses. Huynh: Jazz Pharmaceuticals: Honoraria. Holler: MaaT Pharma: Membership on an entity's Board of Directors or advisory committees; Novartis: Membership on an entity's Board of Directors or advisory committees. Vehreschild: SocraTec R&D GmbH: Consultancy, Speakers Bureau; Pfizer: Consultancy, Speakers Bureau; Ferring: Consultancy, Speakers Bureau; Farmak International Holding GmbH: Consultancy, Honoraria, Speakers Bureau; Bio-Mérieux: Consultancy, Speakers Bureau; Basilea: Consultancy, Speakers Bureau; Arderypharm: Consultancy, Speakers Bureau; Alb Fils Kliniken GmbH: Consultancy, Speakers Bureau; Takeda Pharmaceutical: Research Funding; Seres Therapeutics: Research Funding; Roche: Consultancy, Research Funding, Speakers Bureau; Organobalance: Consultancy, Research Funding, Speakers Bureau; Merck/MSD: Consultancy, Research Funding, Speakers Bureau; MaaT Pharma: Consultancy, Research Funding; Immunic AG: Consultancy, Research Funding, Speakers Bureau; Glycom: Research Funding; Gilead Sciences: Consultancy, Research Funding, Speakers Bureau; Evonik: Research Funding; Da Volterra: Consultancy, Research Funding, Speakers Bureau; Biontech: Research Funding; Astellas Pharma: Consultancy, Research Funding, Speakers Bureau; 3M: Research Funding. Gasc: MaaT Pharma: Current Employment. Plantamura: MaaT Pharma: Current Employment. Mohty: Sanofi: Honoraria, Research Funding; Pfizer: Honoraria; Novartis: Honoraria; Takeda: Honoraria; Jazz: Honoraria, Research Funding; Janssen: Honoraria, Research Funding; Gilead: Honoraria; Celgene: Honoraria, Research Funding; Bristol Myers Squibb: Honoraria; Astellas: Honoraria; Amgen: Honoraria; Adaptive Biotechnologies: Honoraria.

Microtransplantation (MT) is based on injection of HLA-mismatched G-CSF mobilized hematopoietic stem cells, in combination with chemotherapy but without use of conditioning regimen nor immunosuppressive drugs. As a result, a transient microchimerism is induced without engraftment. Its efficacy relies both on host immune system stimulation (recipient versus tumor) and on a graft versus tumor effect. Data are scarce and concern mostly Asian patients with acute myeloid leukemia (AML) and high risk myelodysplastic syndrome (HR-MDS). In comparison to conventional treatment without MT, higher complete remission rates and longer disease free survival and overall survival have been reported. Safety seems acceptable. The most frequent adverse event is non-severe cytokine release syndrome. Risk of GVHD remains very low. Here, we summarize the published data and detail the practical aspects of the procedure. Current data are not strong enough to provide recommendations on indications. Nevertheless, it seems reasonable to propose MT to patients with AML or HR-MDS, regardless of age, presenting an indication for allogeneic stem cell transplantation but ineligible for it. MT is still under investigation and rather be proposed within clinical trials.

Long-term efficacy of anti-PD1 therapy and the need for a consolidation with allogenic haematopoietic stem cell transplantation (allo-HSCT) remain unclear in patients with relapsed/refractory (R/R) Hodgkin lymphoma (HL).We retrospectively analysed 78 patients with R/R HL treated with nivolumab in the French Early Access Program and compared their outcomes according to subsequent allo-HSCT.After a median follow-up of 34.3 months, the best overall response rate was 65.8%, including 38.2% complete responses (CRs). The median progression-free survival (PFS) was 12.1 months. Patients reaching a CR upon nivolumab had a significantly longer PFS than those reaching a partial response (PR) (median = not reached vs 9.3 months, p 0.001). In our cohort, 13 patients who responded (i.e. in CR or PR) to nivolumab monotherapy underwent consolidation with allo-HSCT. Among responding patients, none of those who underwent subsequent allo-HSCT (N = 13) relapsed, whereas 62.2% of those who were not consolidated with allo-HSCT (N = 37) relapsed (p 0.001). There was no difference in overall survival (OS) between the two groups. Five of 6 patients who were not in CR at the time of transplantation (4 PRs and 1 progressive disease) converted into a CR after allo-HSCT.Most patients with R/R HL treated with anti-PD1 monotherapy eventually progressed, notably those who did not achieve a CR. Patients undergoing consolidation with allo-HSCT after anti-PD1 therapy experienced prolonged disease-free survival compared with non-transplanted patients, but this difference did not translate into a benefit in OS. This information should be considered when evaluating the risk/benefit ratio of allo-HSCT after anti-PD1 therapy.

The Francophone Society of Bone Marrow Transplantation and Cellular Therapy (SFGM-TC) organizes annual workshops in the attempt to harmonize clinical practices among different francophone transplantation centers. Here, we report our recommendations regarding the prophylaxis of cytomegalovirus (CMV), herpes simplex virus (HSV), varicella zoster virus (VZV) and hepatitis B virus infection after allogeneic hematopoietic cell transplantation in adult patients.

The Francophone Society of Bone Marrow Transplantation and Cellular Therapy (SFGM-TC) organizes annual workshops in the attempt to harmonize clinical practices among different francophone transplantation centers. Here we report our recommendations regarding detection of the multidrug-resistant bacteria in hematology.

Introduction Intestinal graft-versus-host disease (GvHD), following allogeneic hematopoietic stem cell transplantation (allo-HSCT), has a high mortality rate and a reduced life-expectancy. In this context, failure to respond to steroid therapy is associated with limited further therapeutic options, thereby representing an unmet medical need. Aiming at restoring microbiome functions, fecal microbiota transfer (FMT) has proved to be a promising treatment modality in this challenging clinical setting, with recent studies reporting favorable results in steroid refractory-acute GVHD (SR-aGvHD) patients. Here we report on the use of a next-gen FMT product "MaaT013", a standardized, pooled-donor, high-richness microbiota biotherapeutic, used to treat 29 patients with intestinal aGvHD as part of a compassionate use/expanded access treatment program. Patients and methods Twenty-nine allo-HSCT recipients with steroid-dependent or SR intestinal GvHD (classical aGVHD n=22, late-onset aGVHD n=2; aGvHD with overlap syndrome n=5) were treated with MaaT013 biotherapeutic as part of a compassionate use/expanded access treatment program of the developer MaaT Pharma. These patients had previously received and failed 1 to 5 lines (median 3; 22/29 received ruxolitinib) of GvHD systemic treatments. Each patient received 1 to 3 doses (median: 3; total doses administered: 71) of MaaT013, a 150 mL bag, by enema (n=28) or nasogastric tube (n=1). GI-GvHD response was evaluated 7 days after each administration and 28 days after the first dose. Prepared under Good Manufacturing Practices, MaaT013 biotherapeutics are characterized by a highly consistent richness of 455 ±3% Operational Taxonomic Units and an Inverse Simpson index greater than 20. Batch release specifications are based on potency (viability), identity (diversity), and purity (microbiological safety testing and proportion of proinflammatory species), ensuring the desired consistency across batches. Results We observed a GI overall response rate of 59% (17/29) at day 28 after first dosing, including 9 complete response (CR), 6 very good partial response (VGPR), and 2 partial response (PR). Considering the best GI response achieved, 20/29 patients (69%) achieved at least a PR, with 9 CR, 8 VGPR and 3 PR. Among the 29 treated patients, 16 were still alive at last follow-up (median follow-up (FU): 131.5 days; range [28; 413]) and 6 months overall survival was 54%. Among the 9 patients achieving CR, all were still alive at last follow-up (median FU: 197 days; [49; 301]) and were able to taper or stop steroids and immunosuppressants. Among these 9 patients, three patients presented GI symptom recurrence between 2 and 3 months after dosing. In 2 patients, this recurrence occurred after heavy antibiotic treatment, one of them received an additional MaaT013 dose and achieved a second CR. Of note, among these 9 patients, mild chronic mucosal GvHD symptoms persisted in one patient, and molecular relapse of hematologic malignancy was observed in another. The safety of the MaaT013 microbiota biotherapeutic was satisfactory for all patients. One patient developed "possibly related" sepsis one day after the third dosing but no pathogen was identified in blood cultures, and the patient recovered after a course of antibiotics. Another patient developed C. difficile diarrhea 24 hours post-administration. This was not causally related to MaaT013, as C. difficile testing was negative in the MaaT013 lot. Nosocomial transmission was suspected as the cause as several patients with C. difficile infection were hospitalized in the same unit during this period. Conclusions We herein report for the first time the treatment of 29 patients with steroid-dependent or SR intestinal aGvHD using a full ecosystem, standardized, pooled-donor, high-richness biotherapeutic. The overall response rate was 59% with the off-the-shelf MaaT013 product, which was shown to be safe and effective in these heavily pre-treated and immunocompromised patients, warranting further exploration of the full ecosystem microbiota restoration approach. Disclosures Malard: Astellas: Honoraria; JAZZ pharmaceutical: Honoraria; Sanofi: Honoraria; Janssen: Honoraria; Keocyt: Honoraria; Theralos/Mallinckrodt: Honoraria; Biocodex: Honoraria. Plantamura:MaaT Pharma: Current Employment. Mohty:BMS: Consultancy, Honoraria, Research Funding, Speakers Bureau; Sanofi: Consultancy, Honoraria, Research Funding, Speakers Bureau; Novartis: Consultancy, Honoraria, Research Funding, Speakers Bureau; GSK: Consultancy, Honoraria, Research Funding, Speakers Bureau; Takeda: Consultancy, Honoraria, Research Funding, Speakers Bureau; Jazz Pharmaceuticals: Consultancy, Honoraria, Research Funding, Speakers Bureau; Amgen: Consultancy, Honoraria, Research Funding, Speakers Bureau; Janssen: Consultancy, Honoraria, Research Funding, Speakers Bureau; Stemline: Consultancy, Honoraria, Research Funding, Speakers Bureau; Celgene: Consultancy, Honoraria, Research Funding, Speakers Bureau.

Background: Nivolumab demonstrated remarkable activity in patients with relapse or refractory (R/R) Hodgkin lymphoma (HL). However, long term efficacy and the need for a consolidation with allogenic stem cell transplantation remain unclear. Patient and method: We retrospectively analyzed 78 patients with R/R HL treated with nivolumab in the French Early Access Program and compared their outcome according to subsequent alloHSCT. Results: After a median follow-up of 31.5 months, the best overall response rate was 64%, including 37.3% complete response (CR). The median progression-free survival (PFS) was 12.1 months and median overall survival (OS) was not reached. At 3 years, PFS and OS rates were 35% and 65%, respectively. Patients reaching a CR upon nivolumab had a significantly longer PFS than those reaching a PR (median = not reached vs 10.1 months). In our cohort, 17 patients underwent consolidation with allogenic stem cells transplantation (alloHSCT) after nivolumab therapy (Figure 1). At the time of transplantation, 8 patients were in CR, 5 in partial response (PR) and 4 had progressed of whom 3 received a salvage therapy before alloHSCT. Interestingly, 6 out of 7 patients who were not in CR at the time of transplantation (5 PR and 1 progressive disease) converted into a CR after alloHSCT. At the time of analysis, 14 patients were alive and 13 remained disease-free after a median follow-up of 30.4 months. One-year OS and PFS from alloHSCT were 82% and 76%, respectively. Among responding patients (i.e. in CR or PR) after nivolumab monotherapy, those who underwent subsequent alloHSCT (N=13) had a better outcome than those who were not consolidated with alloHSCT (N=35) (Figure 2). In the transplanted group, none of the patients relapsed whereas in the non-transplanted group 60% of the patients relapsed (p Conclusions: Although patients who achieve a CR upon anti-PD1 therapy may experience prolonged remissions, most R/R HL patients treated with anti-PD1 antibody eventually progress or relapse. Our study demonstrates unprecedented disease-free survival in patients undergoing consolidation with alloHSCT after anti-PD1 therapy. Interestingly, alloHSCT post anti-PD1 can convert incomplete responses into CR in most cases. Despite expected toxicities, alloHSCT after anti-PD1 therapy appears manageable and safe in most patients. Our results suggest that consolidation with alloHSCT may represent a good option in patients treated with anti-PD1, notably in patients who are unable to achieve a CR. Disclosures Herbaux: Gilead Sciences, Inc.: Consultancy, Honoraria; Abbvie: Consultancy, Honoraria; Janssen: Consultancy, Honoraria. Stamatoullas:Millennium Pharmaceuticals, Inc., a wholly owned subsidiary of Takeda Pharmaceutical Company Ltd, Cambridge, MA, USA: Consultancy. Brice:bristol myers squibb: Consultancy, Honoraria. Houot:bristol myers squibb: Consultancy, Honoraria.

Gamma-delta (γδ) T cells contribute to the innate immune response against cancer. In samples of 20 patients upon DLBCL diagnosis, we found that Vδ1+ T cells were the major γδ T cell subset in tumors and PBMCs of patients, while Vδ2 T cells were preponderant in PBMCs of healthy subjects. Interestingly, the germinal center (GC) subtype was associated with an increase in Vδ1+ T cells in tumors, whereas the non-GC subtype was associated with a lower frequency of γδ T cells. While circulating Vδ1+ T cells of patients or HSs mostly exhibited a naive phenotype, the majority of tumor Vδ1+ T cells showed a central memory phenotype. Resident or circulating γδ T cells from patients were not functionally impaired since they produced high levels of IFN-γ. Collectively, our findings are in favor of γδ T cell activation in tumors and open new perspectives for their modulation in DLBCL immunotherapy.

The prognosis of refractory/relapsed acute myeloid leukemia (AML) remains poor. The complete response (CR) rate after relapse is around 25%, with 11% of patients still alive after 5 years. The efficacy and toxicity of fractionated gemtuzumab ozogamicin (fGO; 3 mg/m2, days 1, 4, 7) in combination with intensive chemotherapy were retrospectively evaluated in patients with refractory/relapsed AML. Thirty-six patients (median age 54 years) were included. European LeukemiaNet classification was as follows: favorable (n=6), intermediate-I (n=13), intermediate-II (n=8), adverse (n=9). Median CR duration was 7.16 months (1.63-96.8). The overall response rate was 38.8%, with CR in eight patients (22.2%) and CR with incomplete platelet recovery (CRp) in six patients (16.7%). Two-year overall survival was 26% (95% confidence interval [CI]: 12-42) and 2-year relapse free-survival was 18.5% (95% CI: 6.6-35.0). Salvage therapy with fractionated GO in patients with very high-risk disease produced a 38.8% response rate and may be considered as a bridge therapy to transplant.

Gamma-delta (γδ) T cells contribute to the innate immune response against cancer. In samples of 20 patients upon DLBCL diagnosis, we found that Vδ1

Introduction Intestinal Graft-versus-Host Disease (GvHD), following allogeneic Hematopoietic Stem Cell Transplantation (allo-HSCT), comes with a high mortality rate and a reduced life-expectancy. In this context, failure to respond to steroid therapy is associated with an absence of further therapeutic options, thereby representing an unmet medical need. A marked reduction in gut microbiota diversity leading to loss of functions was strongly associated with reduced overall survival in GvHD, while a high gut microbiota diversity appears to be protective. Aiming at restoring microbiome functions, Fecal Microbiota Transfer proved to be a promising treatment modality in this challenging clinical situation, with recent studies reporting favorable results in steroid refractory-acute GVHD (SR-aGvHD) patients. Here we report on the use of "MaaT013", a standardized, pooled-donor, high-richness microbiota biotherapeutic, used to treat 8 patients with intestinal-predominant aGvHD. Patients and methods Eight allo-HSCT recipients with steroid-dependent or steroid-refractory gastrointestinal GvHD (classical aGVHD n=3, late-onset aGVHD n=2; aGvHD with overlap syndrome n=3) were treated with the MaaT013 biotherapeutic as part of a compassionate use program. These patients had previously received and failed 1 to 5 lines (median 2.5) of GvHD systemic treatments. MaaT013 microbiota biotherapeutics were provided as a pharmaceutical preparation to hospitals by the developer, "MaaT Pharma". Each patient received 1 to 3 doses (median: 3; total doses administered: 21) of MaaT013, a 150 mL bag, by enema (n=7) or nasogastric tube (n=1). GvHD response was evaluated 7 days after each administration and 28 days after the first dose. Prepared under Good Manufacturing Practices, MaaT013 biotherapeutics are characterized by a highly consistent richness of 455 +/- 3% Operational Taxonomic Units (OTUs) and an Inverse Simpson index greater than 20. Batch release specifications are based on potency (viability), identity (diversity), and purity (microbiological safety testing following regulatory guidelines and proportion of proinflammatory species), ensuring the desired consistency between batches. Results We observed 6/8 positive responses at D28 after first dosing, including 3 Complete Responses (CR), one Very Good Partial Response (VGPR), and 2 Partial Responses (PR). Considering the best GI response achieved, all (8/8) patients experienced at least a PR, with 3 CRs, 2 VGPRs and 3 PRs. The 3 patients with CR were still alive at last follow-up (60 to 192 days after last dosing; median: 115 days) and were able to taper and stop steroids and immunosuppressants without relapse of GI symptoms. Of note, among these 3 patients, mild mouth chronic GvHD symptoms persisted in one patient, and relapse of hematologic malignancy was observed in another patient. Among the 8 treated patients, 5 were still alive at last follow-up (60 to 232 days after last dosing; median: 125 days). The safety of the MaaT013 microbiota biotherapeutic was satisfactory in all patients. One patient developed a possibly related sepsis one day after the third MaaT013 administration. In the latter case, no pathogen was identified in blood cultures, and the patient recovered after a course of antibiotics. Conclusions We herein report for the first time the treatment of 8 patients with steroid-dependent or steroid-refractory intestinal aGvHD using a full ecosystem, standardized, pooled-donor, high-richness biotherapeutic. Overall, 3/8 patients attained a complete response following treatment with the off-the-shelf MaaT013 product, shown to be safe and effective in these immunocompromised patients with severe conditions, warranting further exploration of the full ecosystem microbiota restoration approach. Disclosures Malard: Sanofi: Honoraria; JAZZ pharmaceutical: Honoraria; Astellas: Honoraria; Therakos/Mallinckrodt: Honoraria; Keocyte: Honoraria; Janssen: Honoraria. Plantamura:MaaT Pharma: Employment. Carter:MaaT Pharma: Employment. Chevallier:Jazz Pharmaceuticals: Honoraria; Incyte: Consultancy, Honoraria; Daiichi Sankyo: Honoraria. Blaise:Pierre Fabre medicaments: Honoraria; Molmed: Consultancy, Honoraria; Jazz Pharmaceuticals: Honoraria; Sanofi: Honoraria. Mohty:Jazz Pharmaceuticals: Honoraria, Research Funding.

Pseudomonas aeruginosa and Candida albicans are frequently coexisting opportunistic pathogens, responsible for colonization and infection in predisposed patients. They share a virulence specificity relying on auto-inducing, cell density-dependent molecules named quorum-sensing (QS). C. albicans virulence depends on its QS that influences morphological switch from yeast to filamentous form. Similarly, the production of P. aeruginosa virulence factors depends partly on QS molecules. Interactions have been investigated and demonstrated in vitro. P. aeruginosa may kill C. albicans either by producing toxins, such as pyocyanin, or by direct contact on its biofilm-dependent filamentous form. Cross-kingdom communication is a more subtle interaction: C. albicans can adapt its morphology in the presence of P. aeruginosa QS molecules, and inhibit P. aeruginosa QS-dependent virulence factor secretion, through farnesol, one of its QS molecule. But the in vivo relevance of these interactions is still controversial, as models of airway colonization/infection by C. albicans followed by subsequent P. aeruginosa pneumonia give contradictory results, suggesting the probable involvement of the immune system as a third party player. Finally, the authors of clinical studies performed in ventilated patients, indicate that C. albicans colonization could be a risk factor for P. aeruginosa pneumonia. The clinical outcome of C. albicans and P. aeruginosa interaction is uncertain, the virulence modulation demonstrated in these interactions opens new possibilities for future anti-infectious therapeutics.

BACKGROUND There is increasing evidence that excessive blood transfusion may be associated with impaired survival or cardiovascular events. One way to reduce the number of red blood cells (RBCs) is to transfuse 1 unit (1RBC) instead of 2 units of RBCs (2RBC). STUDY DESIGN AND METHODS Patients requiring blood transfusions in hematologic intensive care unit were included in a prospective study using a single RBC unit per transfusion and were compared with an historical cohort who received 2 RBC units per transfusion. RESULTS A total of 1323 units were transfused to 126 patients between 2013 and 2014. The 186 patients in the comparative cohort received a total of 1824 RBC units in a 2-RBC-unit policy between 2010 and 2012. The mean number of units was 7.35 (SD, 5.9 units; 95% confidence interval [CI], 6.5-8.2 units) in the 1RBC group and 8.14 units (SD, 6.2 units; 95% CI, 7.3-8.9 units) in the 2RBC group. The absolute mean difference was −0.79 (95% CI, −1.98 to 0.40; p = 0.09). In the 1RBC allogeneic hematopoietic stem cell transplantation (allo-HSCT) subgroup, a significant reduction in the number of RBC units transfused was observed in comparison with the historical 2RBC allo-HSCT group (5 units vs. 7.7 units; p = 0.01). No anemia-related side effects were reported. Overall survival did not differ between the two groups. CONCLUSION The 1RBC transfusion policy made is feasible in patients with transient hematologic toxicity after chemotherapy. The number of units transfused between the two groups was not different. However, in the allo-HSCT group, the use of a single RBC unit reduced significantly RBC consumption. A randomized trial comparing the two strategies is planned with a medicoeconomic evaluation.

Background Packed red blood cell (PRBC) transfusion is required in hematology patients treated with chemotherapy for acute leukemia, autologous (auto) or allogeneic (allo) hematopoietic stem cell transplantation (HSCT). In certain situations like septic shock, hip surgery, coronary disease or gastrointestinal hemorrhage, a restrictive transfusion strategy is associated with a reduction of infection and death. A transfusion strategy using a single PRBC unit has been retrospectively investigated and showed a safe reduction of PRBC consumption and costs. We therefore designed a study to prospectively demonstrate that the transfusion of a single PRBC unit is safe and not inferior to standard care. Methods The 1versus2 trial is a randomized trial which will determine if a single-unit transfusion policy is not inferior to a double-unit transfusion policy. The primary endpoint is the incidence of severe complication (grade ≥ 3) defined as stroke, transient ischemic attack, acute coronary syndrome, heart failure, elevated troponin level, intensive care unit transfer, death, new pulmonary infiltrates, and transfusion-related infections during hospital stays. The secondary endpoint is the number of PRBC units transfused per patient per hospital stay. Two hundred and thirty patients will be randomized to receive a single unit or double unit every time the hemoglobin level is less than 8 g/dL. All patients admitted for induction remission chemotherapy, auto-HSCT or allo-HSCT in hematology intensive care units will be eligible for inclusion. Sample size calculation has determined that a patient population of 230 will be required to prove that the 1-unit PRBC strategy is non-inferior to the 2-unit PRBC strategy. Hemoglobin threshold for transfusion is below 8 g/dL. Estimated percentage of complication-free hospital stays is 93 %. In a non-inferiority hypothesis, the number of patients to include is 230 with a power of 90 % and an alpha risk of 5 %. Trial Registration 14–128; Clinicaltrials.gov NCT02461264 (registered on 3 June 2015)

International audience; Cervical bilateral lymphadenopathy is a frequent event during chronic lymphocytic leukemia (CLL) natural history. However, lymph node biopsy is generally not required as long as transformation into an aggressive lymphoma (Richter syndrome) is not suspected. We present here a rare case of CLL patient who developed progressive bilateral cervical lymph node and bilateral tonsillar hypertrophy. CLL front-line therapy was ineffective leading to adenectomy and diagnosis of concomitant extramedullary plasmacytoma. Radiotherapy did not result in the disappearance of lymphadenopathy. Adenectomy should be performed in CLL cases to avoid misdiagnosis.

Pseudomonas aeruginosa, a major problem pathogen responsible for severe infections in critically ill patients, triggers, through a functional type-3 secretion system (T3SS), the activation of an intracellular cytosolic sensor of innate immunity, NLRC4. Although the NLRC4-inflammasome-dependent response contributes to increased clearance of intracellular pathogens, it seems that NLRC4 inflammasome activation decreases the clearance of P. aeruginosa, a mainly extracellular pathogen.We sought to determine the underlying mechanisms of this effect of the activation of NLRC4 by P. aeruginosa.We established acute lung injury in wild-type and Nlrc4(-/-) mice using sublethal intranasal inocula of P. aeruginosa strain CHA expressing or not a functional T3SS. We studied 96-hour survival, lung injury, bacterial clearance from the lungs, cytokine secretion in bronchoalveolar lavage, lung antimicrobial peptide expression by quantitative polymerase chain reaction, and flow cytometry analysis of lung cells.Nlrc4(-/-) mice showed enhanced bacterial clearance and decreased lung injury contributing to increased survival against extracellular P. aeruginosa strain expressing a functional T3SS. The mechanism involved decreased NLRC4-inflammasome-driven IL-18 secretion attenuating lung injury caused by excessive neutrophil recruitment. Additionally, in the lungs of Nlrc4(-/-) mice secretion of IL-17 by innate immune cells was increased and responsible for increased expression of lung epithelial antimicrobial peptides. Furthermore, IL-18 secretion was found to repress IL-17 and IL-17-driven lung antimicrobial peptide expression.We report a new role of the T3SS apparatus itself, independently of exotoxin translocation. Through NLRC4 inflammasome activation, the T3SS promotes IL-18 secretion, which dampens a beneficial IL-17-mediated antimicrobial host response.

Pseudomonas aeruginosa and Candida albicans are two pathogens frequently encountered in the intensive care unit microbial community. We have demonstrated that C. albicans airway exposure protected against P. aeruginosa -induced lung injury. The goal of the present study was to characterize the cellular and molecular mechanisms associated with C. albicans -induced protection. Airway exposure by C. albicans led to the recruitment and activation of natural killer cells, innate lymphoid cells (ILCs), macrophages, and dendritic cells. This recruitment was associated with the secretion of interleukin-22 (IL-22), whose neutralization abolished C. albicans -induced protection. We identified, by flow cytometry, ILCs as the only cellular source of IL-22. Depletion of ILCs by anti-CD90.2 antibodies was associated with a decreased IL-22 secretion and impaired survival after P. aeruginosa challenge. Our results demonstrate that the production of IL-22, mainly by ILCs, is a major and inducible step in protection against P. aeruginosa -induced lung injury. This cytokine may represent a clinical target in Pseudomonas aeruginosa -induced lung injury.

Objectives. The number of transfusion is increasing faster than the rate of new blood donations. Further more, a transfusion excess, causing iron overload may have a deleterious effect on long term survival of patient with a malignant blood disease. We therefore tried to reduce the number of Packed Red Blood Cells (PRBC) by transfusing only one PRBC per transfusion instead of two. Material and methods. We conducted a prospective monocentric study between January and December 2013, with an historic comparative arm (from January 2010 to December 2012). We compared the number of PRBC transfused per hospital stay between two cohorts receiving only one PRBC per transfusion (Experimental arm or 1PRBC arm) or two PRBC per transfusion (Historical or 2PRBC arm). All patients admitted for remission-inducing therapy for acute leukemia or allogenic hematopoietic stem cell transplant (alloHSCT) aged ≥ 18 were eligible. The study was approved by local ethical committee. Transfusion triggers were hemoglobin lower than 80g/l or symptomatic anemia. Data analysis was performed in intention to treat. Results are mean ± standard deviation. Results. Seventy-five patients were included in the 1PRBC arm and 194 in the 2PRBC arm. Population distribution for sex, age, pathology and treatment was comparable between the two arms. There was no significant difference of transfused PRBC per hospital stay between the two groups. (7,92±5,39 vs. 9,27±7,42, 15% decrease. p=0,18). However, the restrictive strategy saved 1PRBC per hospital stay (estimated mean of 75 PRBC/year in our center). In the subgroup analysis, alloHSCT recipients from the 1PRBC arm (N=23) received significantly less PRBC than the 2PRBC ones (N=81) (4,13±4,34 vs. 7,51±8,96, 45% decrease. p=0,0058). Savings in this arm is 3 PRBC by hospital stay (estimated mean of 69 PRBC/year in our center). The number of adverse events and symptomatic anemia did not significantly differ between the two arms. Conclusion. A restrictive transfusion strategy is not inferior to a standard 2PRBC transfusion strategy and saves 1 CGR per hospital stay. This effect is especially patent in alloHSCT recipients. A prospective randomized multicentric study is ongoing to confirm these preliminary results. Disclosures No relevant conflicts of interest to declare.

BACKGROUND Hematogones (HG) are normal bone marrow B-cells precursors, characterized on Multiparameter Flow Cytometry (MFC) study by CD19 expression, progressive loss of CD10 and CD34, acquisition of CD45 and CD20. HG level is lowered by age or medullar tumoral infiltration, but is higher (>5%) after chemotherapy, Hematopoietic Stem Cell Transplantation (HSCT) or viral infection. An HG level >0.01% in first complete remission in Acute Myeloid Leukemia (AML) patients is associated with a better Overall Survival (OS) and Progression Free Survival (PFS). Further correlations have been made between HG level and good evolutions in AML patients or HSCT recipients. Although Multiple Myeloma (MM) is a mature B-cell malignancy, no clinical study has focused on HG in MM patients. Furthermore, there is no data on prognostic impact of HG in treated MM patients. However, HG study could be of prime interest for medullar micro-environment evaluation which is not assessed by routine prognostic factors. AIM Our primary objective was to establish the presence and level of HG in the bone marrow of patients with Monoclonal Gammopathy of Undetermined Significance (MGUS), Smoldering Myeloma (SM) or active MM (aMM), and to analyze correlations with clinical characteristics. Our secondary objective was to determine a prognostic correlation between HG level at diagnosis and PFS or OS in aMM patients. METHODS In this monocentric prospective observational study conducted between March 2011 and January 2014, we analyzed all bone marrow samples sent to the MFC lab in our center of CHU de Caen, France. Samples were routinely obtained by bone marrow aspirations at diagnosis for MGUS or MM patients. Medullar cells were analyzed by 4-color MFC, using a CD20-FITc/CD19-PE/CD45-PerCp/CD10-APC panel for HG detection. HG level was calculated over all nuclear medullar cells, samples with less than 100.000 cells were excluded, and sensitivity was 1/104 cells. All biological data were recorded at diagnosis. The median follow-up was 16 months. All statistical analysis, including multivariate analysis, were performed with two-sided 95% confidence intervals. RESULTS A total of 90 patients have been included: 25 MGUS (27%), 12 SM (13%) and 53 aMM (58%). The mean age at diagnosis was respectively 63, 68 and 67 y (35-90), and mean β2-µglobulinemia (β2) was 2.5, 5 and 6.3 mg/l respectively. HG were detected in more than 90% of cases. The mean HG level was significantly higher in MGUS (2.86%, median 2%, p=0.006) or in SM (1.95%, median 1.5%, p=0.019) than in aMM (1.10% median 0.5%) (Figure 1). HG level at diagnosis was inversely correlated with age, plasma cell infiltration, hypoalbuminemia, or β2 (mean HG=2% if β2≤3.5 mg/l, and 0.8% if β2>5 mg/l). HG level was higher in patients with hemoglobin levels ≥10 g/dL (2.8% vs 0.7%, p=0.015). There were no correlations between HG level at diagnosis and white blood cells count, gender, renal insufficiency, plasma cell phenotype nor monoclonal component subtype. In the subgroup of 53 aMM patients, 22% were ISS1, 29% were ISS2 and 49% ISS3. Mean HG levels were 2.1%, 0.8% and 0.85% respectively (p=0.008 between ISS1 vs ISS2+3). All patients but one received a triple regimen chemotherapy including Bortezomib. Patients with HG level >0.5% at diagnosis (median of the group) had a longer median PFS (29.8 vs 13.5 months, n=26 and 27, p=0.002, cf. Figure 2) and a better OS (85% alive vs 60% at 20 months, median not reached, p=0.02). In multivariate analysis, a cut-off of 0.5% of HG at diagnosis was a prognostic factor for PFS in aMM patients (p=0.03, IC=0.14-0.9), with age (p=0.041, IC=1.0-1.09) but not ISS subgroup (p=0.6). Furthermore, patients who achieved Very Good Partial Response (VGPR) or more had higher HG level at diagnosis than patients who achieved Partial Response or less (IC=1.08-6.07, p=0.015). CONCLUSION HG are present in MM patients. The HG level is decreased in MM patients as compared to MGUS, and is inversely correlated with the disease biomarkers or activity. An HG level >0.5% at diagnosis is a good prognostic factor in treated MM patients, and may reflect bone marrow micro-environment condition. Figure 1. HG level and disease stage at diagnosis. Figure 1. HG level and disease stage at diagnosis. Figure 2. PFS of aMM patients sort by HG at diagnosis. Figure 2. PFS of aMM patients sort by HG at diagnosis. Disclosures No relevant conflicts of interest to declare.