Introduction: Achievement of prolonged minimal residual disease (MRD) negativity after both induction and ASCT is a strong independent prognostic marker in mantle cell lymphoma (MCL). A high-dose aracytine- (HA) and salt platinum-containing (P) chemotherapy regimen with Rituximab followed by autologous stem cell transplantation (ASCT) consolidation plus 3 years Rituximab maintenance is considered as a standard of care for untreated younger patients with MCL (Le Gouill et al. NEJM 2017). Obinutuzumab is a glycoengineered, type II, anti-CD20 monoclonal antibody designed to improve the antibody-dependent cell mediated cytotoxicity compared to Rituximab. in vitro experiments suggest that Obinutuzumab may provide better anti-MCL activity (Chiron et al., Blood 2016) than Rituximab but no in vivo data are available regarding Obinutuzumab in naive MCL patients. Methods: The LYMA-101 study is a prospective and open phase II trial testing the effect of Obitunuzumab in untreated MCL patients under 66 years of age and eligible for intensive therapy. Induction consisted of 4 cycles of Obinutuzumab-DHAP (O-DHAP) before consolidation with ASCT (BEAM conditioning plus Obinutuzumab) followed by Obinutuzumab maintenance for 3 years then Obinutuzumab on-demand for MRD positive patients. The LYMA-101 primary objective was the MRD negativity rate after 4 cycles of O-DHAP. MRD in the BM was assessed by IGH clonospecific or bcl1-JH PCR, and quantification with a sensitivity of at least 10-4was reach by dd-PCR following Euro-MRD lymphoma group recommendations. We hypothesized that O-DHAP would be considered as an effective induction chemotherapy regimen if MRD negativity was ≥ 70%. We calculated that a minimum of 83 patients should be included (α risk of 0.05 and β of 0.20 one-sided test). Results: We enrolled 86 patients between Nov 2016 and May 2018. One patient withdrew consent before starting treatment. Sixty-three patients (73.3%) were male and median age was 55.5 years (32-65). MIPI and MIPI-b risk scores were low in 47 (54.7%) and 9 (10.5%) cases, intermediate in 24 (27.9%) and 38 (44.2%) cases and high in 14 (16.3%) and 21 (24.4%) cases. Fifteen patients (17.4%) presented with a blastoid variant. At the time of analysis, median FU was 14 months (3.8-24.4). Twelve patients out of 85 were not evaluable for MRD, essentially due to purely nodal disease and no detectable MCL clone in PB or BM. Among the 73 MRD-informative patients, 62 reached MRD negativity in the BM (84.9%) while 6 were MRD positive after O-DHAP. The remaining 5 patients were not evaluated because 4 stopped treatment during induction due to AEs and one progressed then died. 72 patients underwent ASCT and 68 started Obinutuzumab maintenance. Twelve patients stopped treatment before ASCT (including disease progression in 2 cases and AE in 7 cases), 3 before maintenance (2 because of AE, one died during ASCT), and 9 during maintenance (including disease progression in one case, death in another, AE in 4 cases or other malignancies in 2 cases). In the whole population (n=85), 3 patients progressed, three died. At one year, PFS is 93.4% (IC95%, 84.7-97.2) and OS is 96% (IC95%, 88.1-98.7). Conclusion: The Lyma-101 trial successfully achieved its primary endpoint (84.9% of MRD BM negativity after induction) and demonstrates the high efficacy of O-DHAP as induction chemotherapy regimen before ASCT with an unprecedented high level of MRD negativity, which predict better PFS and OS. Longer FU is needed to evaluate patient outcome after O-DHAP/ASCT/Obinutuzumab on-demand maintenance. However, both PFS and OS are highly encouraging at one year. Keywords: mantle cell lymphoma (MCL); minimal residual disease (MRD); obinutuzumab. Disclosures: Le Gouill, S: Consultant Advisory Role: Roche Genentech; Honoraria: Roche Genentech; Research Funding: Roche Genentech.

Background:Achievement of prolonged minimal residual disease (MRD) negativity after both induction and ASCT is a strong independent prognostic marker in mantle cell lymphoma (MCL). A high‐dose aracytine‐ (HA) and salt platinum‐containing (P) chemotherapy regimen with Rituximab followed by autologous stem cell transplantation (ASCT) consolidation plus 3 years Rituximab maintenance is considered as a standard of care for untreated younger patients with MCL (Le Gouill et al. NEJM 2017). Obinutuzumab is a glycoengineered, type II, anti‐CD20 monoclonal antibody designed to improve the antibody‐dependent cell mediated cytotoxicity compared to Rituximab. In vitro experiments suggest that Obinutuzumab may provide better anti‐MCL activity (Chiron et al., Blood 2016) than Rituximab but no in vivo data are available regarding Obinutuzumab in naive MCL patients.Aims:The LYMA‐101 study is a prospective and open phase II trial testing the effect of Obitunuzumab in untreated MCL patients under 66 years of age and eligible for intensive therapy. Induction consisted of 4 cycles of Obinutuzumab‐DHAP (O‐DHAP) before consolidation with ASCT (BEAM conditioning plus Obinutuzumab) followed by Obinutuzumab maintenance for 3 years then Obinutuzumab on‐demand for MRD positive patients.Methods:The LYMA‐101 primary objective was the MRD negativity rate after 4 cycles of O‐DHAP. MRD in the BM was assessed by IGH clonospecific or bcl1‐JH PCR, and quantification with a sensitivity of at least 10‐4 was reach by dd‐PCR following Euro‐MRD lymphoma group recommendations. We hypothesized that O‐DHAP would be considered as an effective induction chemotherapy regimen if MRD negativity was ≥ 70%. We calculated that a minimum of 83 patients should be included (α risk of 0.05 and β of 0.20 one‐sided test).Results:We enrolled 86 patients between Nov 2016 and May 2018. One patient withdrew consent before starting treatment. Sixty‐three patients (73.3%) were male and median age was 55.5 years (32–65). MIPI and MIPI‐b risk scores were low in 47 (54.7%) and 9 (10.5%) cases, intermediate in 24 (27.9%) and 38 (44.2%) cases and high in 14 (16.3%) and 21 (24.4%) cases. Fifteen patients (17.4%) presented with a blastoid variant. At the time of analysis, median FU was 14 months (3.8–24.4). Twelve patients out of 85 were not evaluable for MRD, essentially due to purely nodal disease and no detectable MCL clone in PB or BM. Among the 73 MRD‐informative patients, 62 reached MRD negativity in the BM (84.9%) while 6 were MRD positive after O‐DHAP. The remaining 5 patients were not evaluated because 4 stopped treatment during induction due to AEs and one progressed then died. 72 patients underwent ASCT and 68 started Obinutuzumab maintenance. Twelve patients stopped treatment before ASCT (including disease progression in 2 cases and AE in 7 cases), 3 before maintenance (2 because of AE, one died during ASCT), and 9 during maintenance (including disease progression in one case, death in another, AE in 4 cases or other malignancies in 2 cases). In the whole population (n = 85), 3 patients progressed, three died. At one year, PFS is 93.4% (IC95%, 84.7–97.2) and OS is 96% (IC95%, 88.1–98.7).Summary/Conclusion:The Lyma‐101 trial successfully achieved its primary endpoint (84.9% of MRD BM negativity after induction) and demonstrates the high efficacy of O‐DHAP as induction chemotherapy regimen with an unprecedented high level of MRD negativity. Longer FU is needed to evaluate patient outcome after O‐DHAP/ASCT/Obinutuzumab on‐demand maintenance. However, both PFS and OS are highly encouraging at one year.

Introduction: Angioimmunoblastic T-cell lymphoma (AITL) is the most frequent peripheral T-cell lymphoma. Treatment with CHOP has limited efficacy. In the recent analysis of the REVAIL study, a phase 2 trial assessing the combination of Lenalidomide and CHOP in previously untreated patients with AITL, the mutational landscape (i.e TET2, DNMT3A, IDH2 or RHOA) has limited impact on survival (Lemonnier, Safar et al. ASH 2018), making important to find alternative methods to predict the prognosis of AITL patients. Methods: The 72 patients included in REVAIL study with a centrally confirmed diagnosis of AITL are analyzed. Bone marrow involvement (BMI) was determined locally on BM trephine biopsy. Fresh blood samples were centrally collected for flow cytometry and DGGE PCR analyses aiming at detecting circulating neoplastic T cells by aberrant immunophenotype or a monoclonal TCR rearrangement. Total metabolic tumor volume (TMTV) was measured on baseline PET CT as previously reported (PMID: 28864629). Results: At inclusion, 33/67 (49%) patients had a BMI. No difference in median age, performance status or presence of B symptoms was observed between patients with or without BMI. However, IPI was higher in patients with BMI (60% of patients with BMI vs 30% of patients without BMI had IPI 4-5, p = 0.02). Although the complete metabolic response rate was similar in patients with or without BMI [13/33 (39%) vs 18/34 (53%) (p = 0.33)], BMI was associated to poorer outcome, as the median progression-free survival (PFS) was 9 months versus 36 months (p = 0.029) and the median overall survival (OS) was 17 vs 54 months (p = 0.006) in patients with or without BMI, respectively. We thus compared the relevance of three prognostic models [International prognosis index, Prognostic Index for Peripheral T-Cell Lymphoma (PIT), and Prognostic Index for AITL] used in T-cell lymphomas. As shown in the figure, PIT, which includes BMI as a prognostic factor, gave the best discrimination between high-risk and low-risk patients with a 2yr OS of 38% for PIT 3-4 and 79% for PIT 0-2. Flow cytometry identified abnormal circulating cells in 30/51 (59%) patients, and DGGE PCR identified a circulating clonal population in 39/59 (66%) patients. However, the presence of circulating cells identified by flow cytometry or PCR had no impact on survival and was not correlated with the presence of BMI. We also observed that lymphomas with BMI had a higher percentage of neoplastic T cells in the tumor and higher TMTV. Mutational analysis revealed that BMI was present in 12/13 (92%) IDH2-mutated samples and in 19/47 (40%) IDH2 unmutated samples (p = 0.001). Keywords: angioimmunoblastic T-cell lymphoma (AITL); prognostic indices. Disclosures: Bachy, E: Consultant Advisory Role: Beigene, Celgene; Honoraria: Amgen, Roche; Research Funding: Takeda. Cartron, G: Consultant Advisory Role: Celgene; Honoraria: Celgene. Casasnovas, O: Consultant Advisory Role: Celgene, Roche, Takeda, BMS, MSD, Gilead, Janssen; Research Funding: Takeda, Gilead, Roche. Meignan, M: Honoraria: Roche. Gaulard, P: Consultant Advisory Role: Takeda; Honoraria: Takeda; Research Funding: Takeda.

Allogeneic haematopoietic stem-cell transplantation (HSCT) is the only curative treatment for myelofibrosis. We retrospectively analyzed the outcome of patients who underwent allogeneic HSCT, 1994–2008, and the potential risk factors affecting non-relapse mortality (NRM), OS and relapse-free survival (RFS). A total of 39 patients, 15–65 (median 49) years old, diagnosed with primary (n=27) or secondary (n=12) myelofibrosis underwent HSCT (25 related and 14 unrelated). In ten patients, disease had transformed into acute leukaemia. Lille prognosis score was low for 9, intermediate for 16 and high for 14 patients. The conditioning regimen was myeloablative (MAC) for 15 and reduced-intensity (RIC) fludarabine-based for 24, with successful engraftment in 38 patients. A total of 31 patients developed grade I–IV GvHD; 19 developed chronic GvHD. The 3-year OS, RFS and NRM rates (95% confidence interval) were 60% (42–74), 54% (37–59) and 30% (30–45), respectively.

Abstract Introduction: HSCT has been developed in few Wm cases and is nowadays challenged by other innovative approaches. However, high dose therapy followed by autologous HSCT (HD-auto) produces high response rate and some long term responses while allogeneic HSCT performed after either myeloablative (MA-allo) or reduced intensity conditioning (RIC-allo) regimens may be cure of Wm (Dreger 1998, Tournilhac 2003, Maloney 2006). Methods: We updated and extended our retrospective experience on 32 HD-auto, 11 MA-allo and 11-RIC-allo performed from 1990 to 2006 in 51 patients from 18 institutions. A MA-allo and a RIC-allo were performed in 1 and 2 cases respectively following relapse after a 1st HD-auto. Results: Data are presented in the table. HD-auto MA-allo RIC-allo Nb 32 11 11 Median age at transplant 56 46 56 Interval: diagnosis-transplant 38 50 74 Chemoresistance at transplant 25% 36% 55% Conditioning regimen BEAM (13), TBI/melphalan (9), TBI/endoxan (7), other (3) TBI/endoxan (9), other (2) TBI/fluda (10), other (1) Donor Sibling (9), unrelated (2) Sibling (8), unrelated (2), cord blood (1) Median follow up (m) 45 (3–121) 68 (3–132) 22(2–60) Relapse 18 (56%) 4 (36%) 0 Transplant related mortality 12,5% (one 2th cancer) 36% 27% (one 2th cancer) overall survival (1;3;5y) 87%, 77%, 58% 64%, 54%, 54% 82%, 68%, 68% Event free survival (5y) 25% 48% 68% Acute GVHD developed following 9 MA-allo [Grade III-IV (n=1)] and 8 RIC-allo [Grade III-IV (n=1)]. Chronic GVHD developed following 7 MA-allo [limited (n=5), extensive (n=2)] and 5 RIC-allo [limited (n=2), extensive (n=3)]. Conclusion: We confirm that autologous HSCT achieves some long term responses even in heavily pretreated patients. Allogeneic HSCT induces very long term disease control and may cure WM. Specially, the RIC-allo gives impressive results on disease control in a set of older patients, with refractory disease, mostly heavily pretreated.

ZFHX1B encodes Smad-interacting protein 1, a transcriptional corepressor involved in the transforming growth factors β (TGFβ) signaling pathway. ZFHX1B mutations cause a complex developmental phenotype characterized by severe mental retardation (MR) and multiple congenital defects. We compared the distribution of ZFHX1B transcripts during mouse and human embryogenesis as well as in adult mice and humans. This showed that this gene is strongly transcribed at an early stage in the developing peripheral and central nervous systems of both mice and humans, in all neuronal regions of the brains of 25-week human fetuses and adult mice, and at varying levels in numerous nonneural tissues. Northern blot analysis suggested that ZFHX1B undergoes tissue-specific alternative splicing in both species. These results strongly suggest that ZFHX1B determines the transcriptional levels of target genes in various tissues through the combinatorial interactions of its isoforms with different Smad proteins. Thus, as well as causing neural defects, ZFHX1B mutations may also cause other malformations.

Mutations or deletions involving ZFHX1B (previously SIP1) have recently been found to cause one form of syndromic Hirschsprung disease (HSCR), associated with microcephaly, mental retardation, and distinctive facial features. Patients with the characteristic facial phenotype and severe mental retardation, but without HSCR, have now also been shown to have mutations in this gene. Mutations of ZFHX1B are frequently associated with other congenital anomalies, including congenital heart disease, hypospadias, renal tract anomalies, and agenesis of the corpus callosum (ACC). We present the clinical data and mutation analysis results from a series of 23 patients with this clinical syndrome, of whom 21 have proven ZFHX1B mutations or deletions (15 previously unpublished). Two patients with the typical features (one with and one without HSCR) did not have detectable abnormalities of ZFHX1B. We emphasize that this syndrome can be recognized by the facial phenotype in the absence of either HSCR or other congenital anomalies, and needs to be considered in the differential diagnosis of dysmorphism with severe mental retardation +/- epilepsy.

Hirschsprung disease (HD) has been described in association with microcephaly, mental retardation and characteristic facial features, delineating a syndrome possibly caused by mutations localized at chromosome 2q22--q23. We have analyzed a de novo translocation breakpoint at 2q22 in one patient presenting with this syndrome, and identified a gene, SIP1, which is disrupted by this chromosomal rearrangement. SIP1 encodes Smad interacting protein 1, a new member of the delta EF1/Zfh-1 family of two-handed zinc finger/homeodomain transcription factors. We determined the genomic structure and expression of the human SIP1 gene. Further analysis of four independent patients showed that SIP1 is altered by heterozygous frameshift mutations causing early truncation of the protein. SIP1, among other functions, seems to play crucial roles in normal embryonic development of neural structures and neural crest. Its deficiency, in altering function of the TGF beta/BMP/Smad-mediated signalling cascade, is consistent with some of the dysmorphic features observed in this syndrome, in particular the enteric nervous system defect that underlies HD.

Comparative genomic hybridization (CGH) is a new molecular cytogenetic technique which can detect and map whole and partial aneuploidies throughout a genomic specimen DNA without culturing specimen cells. Thus, CGH may be used as a comprehensive and rapid screening test in prenatal unbalanced chromosomal abnormalities detection. We report the results of the first prospective study to evaluate the use of the CGH technique on uncultured amniocytes. Seventy-one amniotic fluid samples, obtained by transabdominal amniocentesis between the 14th and 35th weeks of gestation, were simultaneously investigated using CGH and conventional cytogenetics. Amniocentesis were done for advanced maternal age (21.1%), fetal ultrasound anomalies (73.3%) and high level of biochemical markers in maternal serum (5.6%). Sixty-six (93%) informative results were generated on a total of 71 analysed specimens. Fifty-nine samples were reported as disomic for all autosomes with a normal sex chromosome constitution using CGH and conventional cytogenetics. Among them, three pericentromeric chromosomal inversions were undetected by CGH analysis. Seven numerical aberrations were characterized, including one case of trisomy 13, one case of trisomy 18 and five cases of trisomy 21. Advantages and limitations of CGH for a rapid prenatal screening of unbalanced chromosomal aberrations are discussed.

We report on clinical and cytogenetic findings in a boy with partial 9p duplication, dup(9)(p21pter). Clinical manifestations included facial and hand anomalies and mental retardation. Fluorescence in situ hybridization (FISH) and comparative genomic hybridization (CGH) were used to characterize further and confirm the conventional banding data. Investigation by FISH using whole chromosome 9 paint probe showed that the additional material was derived from chromosome 9. Using CGH, a region of gain was found in the chromosome segment 9p21pter. YACs and telomeric probes confirmed the duplicated region. Using the all-human telomeric sequences probe, intrachromosomal telomeric signal was noted on the short arm of the abnormal chromosome 9. Mechanism of formation of the duplication, including intrachromosomal telomeric sequences, is discussed.