Abstract: Mantle cell lymphoma (MCL) accounts for approximately 6% of non-Hodgkin's Lymphoma (NHL) in adults. MCL commonly responds to initial therapy but inevitably patients relapse and response duration decreases from one salvage therapy to the next. Indeed, there is an urgent need to control and/or eradicate residual MCL cells that are responsible for early and late relapses. Maintenance with Rituximab (RM) after R-CHOP has been shown to prolong OS in elderly MCL patients treated with R-CHOP (Kluin-Nelemans et al. NEJM). Induction with high-dose cytarabine followed by autologous stem cell transplant (ASCT) consolidation is standard of care for young patients but RM after ASCT has never been investigated so far. The LyMa trial (ClinicalTrials.gov, NCT00921414) is a prospective international randomized phase III trial that investigated RM after ASCT in young previously untreated MCL patients. Patients were included at diagnosis ( 〈 66y; stage 〉 I, untreated, diagnosis of MCL according to WHO 2008 classification). Induction immuno-chemotherapy consisted of 4 courses of R-DHAP every 21 days (Rituximab, Dexamethasone, High-dose cytarabine, salt Platinum) followed by ASCT consolidation. Patients who were not in response (CR/CRu or PR) after R-DHAP received 4 additional courses of R-CHOP-14 before ASCT. The conditioning regimen for ASCT was R-BEAM. Patients in response after ASCT were randomized (1:1) between RM or no RM. RM consisted of one infusion of Rituximab (375mg/m2) every 2 months for 3 years. The primary endpoint was event-free survival (EFS) calculated from time of randomization; events were defined as disease progression, relapse, death, severe infection or allergy to Rituximab. Progression-free survival (PFS) and overall survival (OS) from time of diagnosis and time of randomization were secondary endpoints. The interim analysis showed a trend for a longer EFS and PFS in favor of RM arm. (Le Gouill et al, ASH 2014, abs 146). Herein, we present the results of the final analysis. RESULTS. Two hundred and ninety nine patients were enrolled from September 2008 to August 2012. Demographic and clinical characteristics of the patients were as followed: median age of 57y (27-65), 79% of male, MIPI-low in 53.2%, MIPI-I in 27.4% and MIPI-H in 19.4%. After inclusion, 277 patients completed the 4 courses of R-DHAP. The CR/CRu rate after R-DHAP was 77.3% and ORR was 89.3%. Twenty patients received R-CHOP. In all, 257 patients (including 12 patients who received R-DHAP/R-CHOP) underwent ASCT. After ASCT, 240 patients were randomized (RM, n=120; no RM, n=120). Median follow-up (mFU) from inclusion and from randomization were 54.4m (52.7-59.2) and 50.2m (46.5-54.2), respectively. The mPFS and mOS from inclusion in an intention to treat analysis were not reached; the 4y-PFS and OS were 67.8% (95%CI, 62.1 to 72.8) and 78% (95%CI; 72.8 to 82.3), respectively. According to EFS definition, 47 (39.2%) patients had an event in the no RM versus 25 (20.8%) in the RM arm. The mEFS from randomization was not reached in both arms. The 4y-EFS was 61.4% (95%CI; 51.3 to 69.9) in the no RM arm vs 78.9% (95%CI; 69.6 to 85.6) in the RM arm (p=0.0012). The EFS duration was significantly superior in the RM arm with a 54.3% reduction in the risk of event (Hazard ratio (HR)= 0.457; 95%CI, 0.28 to 0.74; p=0.0016). The median PFS and OS from randomization were not reached in both arms. The 4y-PFS and OS from randomization were superior in the RM arm: 82.2% (95%CI; 73.2 to 88.4) vs 64.6% (95%CI; 54.6 to 73) (p=0.0005) and 88.7% (95%CI; 80.7 to 93.5) vs 81.4% (95%CI; 72.3 to 87.7)(p=0.0413). Patients in the RM arm had a 60% reduction of risk of progression (HR=0.4; 95%CI, 0.23 to 0.68; p=0.0007) and a 50% reduction of risk of death (HR=0.5; 95%CI, 0.25 to 0.98; p=0.0454). The per protocol analysis yielded similar results. In conclusion, The LyMa trial demonstrates for the first time that RM after ASCT prolongs EFS, PFS and OS. Thus, 4 courses of R-DHAP plus ASCT (without TBI) followed by RM maintenance (one infusion every 2 month for 3 years) is a new standard of care for young MCL patients. Disclosures Thieblemont: Gilead: Consultancy; Roche: Consultancy; Janssen: Consultancy. Ribrag:Pharmamar: Membership on an entity's Board of Directors or advisory committees; Esai: Membership on an entity's Board of Directors or advisory committees; Incyte: Membership on an entity's Board of Directors or advisory committees; NanoString: Membership on an entity's Board of Directors or advisory committees; Gilead: Membership on an entity's Board of Directors or advisory committees; Infinity: Membership on an entity's Board of Directors or advisory committees; BMS: Membership on an entity's Board of Directors or advisory committees; ArgenX: Research Funding. Casasnovas:BMS: Consultancy, Honoraria; Sanofi: Consultancy, Honoraria; Takeda: Consultancy, Honoraria; Abbvie: Consultancy, Honoraria; Gilead: Consultancy, Honoraria, Research Funding; ROCHE: Consultancy, Honoraria, Research Funding. Haioun:Janssen: 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; Sandoz: Honoraria, Membership on an entity's Board of Directors or advisory committees; Celgene: Honoraria, Membership on an entity's Board of Directors or advisory committees; Roche: Honoraria, Membership on an entity's Board of Directors or advisory committees. Hermine:Celgene: Research Funding; AB science: Consultancy, Equity Ownership, Membership on an entity's Board of Directors or advisory committees, Patents & Royalties, Research Funding, Speakers Bureau; Novartis: Research Funding; Alexion: Research Funding.

Abstract: A high frequency of diverse activating mutations in costimulatory/TCR-related signaling genes occurs in AITL and other TFH-derived PTCL. Deregulated TCR activation may play a role in the pathogenesis of TFH-derived PTCL, paving the way for developing novel targeted therapies.

Abstract: Introduction.The BCL-2 inhibitor venetoclax has demonstrated high efficiency in relapsed/refractory (R/R) CLL patients with an overall response rate (ORR) of 79%, regardless of the TP53gene status. Venetoclax has then been EMEA-approved for CLL patients with TP53disruption who are unsuitable for or have failed a BCR inhibitor (BCRi) and those without TP53 inactivation who have failed both immunochemotherapy and a BCRi. Whether this agent provides a well-balanced safety/efficacy profile and a prolonged survival in real-world practice remains to be investigated. Methods. An early access program (ATU) of venetoclax was available in France between July 22thand December 4th, 2016 for R/R CLL patients as per EMEA label. We retrospectively analyzed the outcome of patients included in this program who had received at least one day of venetoclax. Data quality was ensured using on-site data verification and computerized discrepancy errors. Results. Data concerning both clinical features andoutcome were available for 72 of the 93 patients for whom venetoclax was requested in this program. Among them, only 63 patients received at least one day of venetoclax for progressive CLL or Richter syndrome (RS) and were included in the present analysis. Median age was 69 years (range, 25-89) and sex ratioM/F was 47/16. A total of 56 patients received venetoclax for CLL and 7 for RS. Patients had previously received a median of 4 prior therapeutic lines (range, 0-7) including FCR in 43 (68%) of them, BTK inhibitor (BTKi) in 46 (73%) and PI3Kδ inhibitor (PI3Kδi) in 21 (33%); 5 had prior autologous stem cell transplantation (SCT) and 4 allogeneic SCT. At time of treatment with venetoclax, 32 (76%) patients carried TP53disruption (data available for 42 patients) and 19 (61%) had complex karyotype (CK) defined as ≥ 3 abnormalities (data available for 31 patients). IGHV mutational status was available for 26 patients. Treatment was administered as per label recommandations with a 5-week ramp up phase until the target dosage of 400 mg per day. Median follow-up was 17 months. Median time on therapy was 11.9 months (range, 0.1-24.6). Among adverse events of interest, tumor lysis syndrome (TLS) was observed in 19% of case, most of them being biological TLS and 3% were clinical TLS, and 15 (24%) patients developed infections requiring hospitalization. Autoimmune cytopenia was seen in 9.5% of patients. Four (7%) patients developed RS while on venetoclax for progressive CLL. To date, a total of 30% of patients remains on therapy. Three patients proceeded to allo-SCT after venetoclax therapy. Among the 7 patients who received venetoclax for RS, 2 had an objective response that lasted 7 and 14 months. However, median overall survival (OS) was only 1.1 months (95% CI, 0.7-1.5). Regarding the CLL cohort, ORR was 73%. It did not significantly differ according to the TP53status (90% with TP53disruption vs 69%, P= 0.189). Conversely, CK was associated with a lower ORR (92% vs 56%, P= 0.024). No impact of the type of prior BCRi (BTKi vs PI3Kδ inhibitor) was noted. 2-year progression-free survival (PFS) was 62% without significant impact of the TP53status (59% in case of TP53disruption vs 68% if wt-TP53,P= 0.587). Patients with CK had 2-year PFS of 44% compared to 78% for those without CK (P= 0.182). 2-year overall survival (OS) was 65% for the whole cohort and significantly better for responding patients than for non responders (76% vs 31%, P 〈 0.001). TP53disruption was associated with 2-year OS of 65% vs 90% (P= 0.176). Patients with CK had 53% of 2-year OS vs 62% for the remaining cohort (P= 0.236). There was no difference for the type of prior therapies (BTKi, PI3Kδ inhibitor or prior SCT) or IGHV mutational status. Patients who stopped venetoclax therapy had a very poor outcome with a median OS of 5 months. Conclusions.Our real-life study shows response rates and survival data that are in line with those observed in pioneer venetoclax clinical trials. CK should be evaluated as a predictive factor for response to venetoclax. Disclosures Herbaux: Janssen: Consultancy, Honoraria; Abbvie: Consultancy, Honoraria; Gilead Sciences, Inc.: Consultancy, Honoraria. Laribi:Roche: Other: Grant; Teva: Other: Grant; Hospira: Other: Grant; Sandoz: Other: Grant; Gilead: Other: Personal fees; Novartis: Other: Grant and personal fees; Takeda: Other: Grant and personal fees; Amgen: Other: Personal fees. Feugier:Abbvie: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Gilead: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Roche: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Janssen: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding. Guieze:abbvie: Honoraria; janssen: Honoraria; gilead: Honoraria.

Abstract: Unavailability of Carmustine and its dramatically increased cost by nearly 10 fold has led to its replacement by bendamustine (Be) and an increase use of Bendamustine-based (BeEAM) conditioning regimen before autologous stem cell transplantation for lymphoma. The aim of this study was to evaluate the safety of the BeEAM regimen in the real life use in several French centers. Median age of the 386 patients (233 male, 153 female) was 55 years (17-72). The majority of patients had aggressive B-cell (40%), follicular (17%), Hodgkin's (17%) and mantle cell lymphoma (15%). Two hundred and forty six patients (64%) were transplanted after 2nd line chemotherapy and the median number of prior lines of chemotherapy of 2 (1-9). Two hundred and sixty patients (67%) had received prior platinum chemotherapy and only 4% had a history of prior chronic renal failure (Table 1). The median creatinine level at conditioning initiation was 71(36-206) µmol/l. Be was administered at a median dose of 191 mg/m2/day (50-250) on day -7 and -6. Thirty two percent received 100-160 mg/m²/d and 58% of patients received more than 160 mg/m²/d. Median 24h-hydration volume was 3 l (1-6) which began within median time of 18 h (1-72) prior to conditioning initiation. The median duration time of Be perfusion was 60 min (30-143). Grade 1-4 acute renal failure (ARF) was reported in 107 cases (28%) (G ≥2; 34%) and appeared after a median time of 2 days (1-18) after conditioning start. Melphalan dosage was reduced, due to renal failure, in 10% of patients (Table 2). 84% of patients normalized their creatinine level within a median time of 10 days (1-77). The most frequent reported Grade 1-4 toxicities were mucositis (84%), gastroenteritis (53%), skin toxicity (34%), colitis (29%), liver toxicity (19%), pneumonitis (5%) and cardiac rhythm disorders (4%). Opportunistic infection was documented in 9.5% of patients, HHV6 reactivation in 6% of patients. Ten percent of patients needed intensive care management and toxic death was estimated at 5% (Table 3). Patients received a median of 3 (0-34) packed red blood cells and 4 (0-56) platelets units. The median time to neutrophils 〉 0.5 G/L and platelets 〉 20 G/L were 10 (0-50) and 12 (0-210) days. The median time of hospital stay was 23 (12-85) days. In comparison with the group of patient without renal failure, the group of patients with ARF had older age (58 vs 54), higher rate of pre-transplant chronic renal failure (10% vs 1%), higher rate of platinum treatment (77% vs 64%), higher day1 creatinine level (81 vs 69) and received higher median bendamustine (199 vs 182). Colitis (p=0.039), pneumonitis (p=0.008), cardia arrhythmia (p= 〈 0.0001), intensive care admission (p= 〈 0.0001), need for blood transfusion (p= 〈 0.0001), hospital stay duration (p= 〈 0.0001), and death (p= 〈 0.0001), were more frequent in patients with post conditioning renal failure. In multivariate analysis, creatinine level at day1, bendamustine dose 〉 160mg/m2 and age were independent prognostic factors for ARF. A three-point clinical predictor score for acute renal failure was identified and included creatinine level 〉 65µmol/l, bendamustine dose 〉 160mg/m² and age 〉 57 years. ARF stratified by score, was 4% with score 0, 17% with score 1, 30% with score 2 and 45% with score 3. In conclusion, BeEAM induced 5% non-relapse mortality with high rate of renal toxicity. A simple, three-point scoring system can stratify patients by levels of risk for ARF. Rapid identification of higher risk patients may allow a reduction of the bendamustine dose to improve clinical outcomes. Prospective comparative studies are needed to confirm toxicity extents of this conditioning as compared with other type of high dose therapy. Disclosures Soussain: Pharmacyclics: Research Funding; Celgene: Research Funding; Roche: Research Funding. Malak:Novartis: Membership on an entity's Board of Directors or advisory committees.

Abstract: Introduction CLL2007FMP (fit medically patients) is a Randomized Phase-III Trial conducted by the French Cooperative Group on CLL and WM (FCGCLL/WM) and the “Groupe Ouest-Est d'Etude des Leucémies et Autres Maladies du Sang” (GOELAMS), comparing FC plus Rituximab (FCR) to FC plus Campath (FCCam) in previously untreated fit patients with chronic lymphocytic leukemia (CLL). Early results showed that the FCCam regimen was associated with an unfavourable safety profile limiting significantly its use in this indication (Blood 2012). We present here the results of the extended follow up of the CLLFMP2007 trial, with particular emphasis on survival data, minimal residual disease (MRD) and late adverse events. Methods In this trial, 178 younger ( 〈 65) fit patients (pts) (cumulative illness rating scale (CIRS) score of up to 6), were enrolled between November 2007 and January 2009. Cases with del(17p) were excluded. Pts were randomly assigned to receive 6 oral courses of FCR (n=83) or FCCam arm (n=82). The primary endpoint of the study was 3-year progression-free survival (PFS). Secondary endpoints were safety, response to treatment, overall survival (OS) and MRD. MRD evaluation was performed by 6-color flow cytometry in an oligocentric manner. MRD testing was scheduled before therapy initiation and at final evaluation, (i.e. 3 months after completion of immunochemotherapy) where it was to be assessed for all responding patients in both peripheral blood (PB) and bone marrow (BM). Recruitment was interrupted in January 2009 after 165 pts had been randomized due to an excess of mortality in the FCCam arm. Results PFS and OS were not significantly different between the two arms. With a median follow-up of 55.5 months (interquartile range, 50-60), 57 pts in the FCCam arm were free of disease progression compared with 50 in the FCR arm, with a 3-year estimated PFS at 81% in both arms (p=0.80). Fourteen pts died in the FCCam arm (7 from progression and 7 from toxicity) and 9 died in the FCR arm (all from progression), with a 3-year estimated survival at 90% vs. 88% (p=0.85). PFS was significantly impacted by IGHV mutational status (p=0.001), Binet stage (p=0.0002) and MRD level. At final evaluation, MRD was established using the result in PB samples (available for 120 patients) and was determined in 103 pts by combining the results from blood and BM samples. Interpretation was based firstly on the use of the classical 10-4 threshold as reference and secondly on the limit of detection of the technique (0.7x10-5). In MRD-positive patients, the median PFS was 44.7 months (PB) whereas it was not reached in the group with MRD lower than 10-4 (p 〈 0.0001, figure 1) ; similar data were found in MRD-positive PB+BM patients with a median PFS of 46 months whereas it was not reached in the group with MRD lower than 10-4 (p=0.002). No significant difference was found regarding OS but follow-up is still short for this evaluation. Similar results were observed when considering the limit of detection of the MRD technique (data not shown). Late toxicities (occurring after the final evaluation at 3 months after the end of treatment or at the ninth month when treatment was prematurely stopped) included : 1 bile duct cancer, 1 myelodysplastic syndrome, 1 transient ischemic attack, 1 lung adenocarcinoma and one prostate cancer in the FCR arm and 3 febrile neutropenia, 3 pneumonia (1 due to legionella), 1 pneumococcal sepsis, 1 bronchitis, 1 toxoplasma eye infection, 1 pyelonephritis, 2 herpes zoster, 1 acrodermatitis, 1 subdural hematoma, 1 autoimmune thrombocytopenia, 1 agranulocytosis, 1 autoimmune haemolytic anaemia in the FCCam arm. Conclusion Results of this extended follow-up of the CLL2007FMP trial confirm the absence of superiority of the FCCam regimen on OS and PFS. Interestingly, longer follow-up did not reveal a higher rate of late toxicity in FCCam arm, notably in terms of secondary malignancies; Similarly to early toxicity, late was adverse events were mainly infectious. Finally, MRD status determined by 6-color technique in PB and/or BM at post-treatment evaluation was predictive of PFS whatever the treatment arm. This finding is in line with recent reports in other studies pointing out to the powerful value of MRD as prognostic factor, supporting its use as PFS surrogate primary endpoint in clinical trials. Disclosures: Feugier: roche: Honoraria. Cazin:roche: meeting invitation Other, Membership on an entity’s Board of Directors or advisory committees; GSK: meeting invitation, meeting invitation Other, Membership on an entity’s Board of Directors or advisory committees.

Abstract: Background: Ruxolitinib (RUX), a JAK1/JAK2 inhibitor, and venetoclax (VEN), a BCL-2 inhibitor are 2 drug candidates recently identified as promising candidate for the treatment of T-Cell prolymphocytic leukemia (T-PLL). We recently reported that JAK/STAT pathway inhibition with RUX enhances BCL-2 dependence, thereby sensitizing T-PLL cells to VEN (Herbaux et al., Blood, 2021). We also showed that JAK/STAT pathway mutational status could impact RUX activity. Here, we report results on the 15 first patients who were treated with RUX and VEN oral combination for T-PLL. All patients were refractory to, or ineligible for alemtuzumab, the principal therapeutic option to date. Methods: In this multicenter retrospective study from the French Innovative Leukemia Organization, 15 patients with T-PLL (according to consensus criteria) were included. All patients were informed about the off-label use of this combination and provided informed consent. Patients received a maximum dose of RUX 15 mg twice daily, and VEN 800 mg daily. VEN was started with daily ramp-up from 20 mg to 800 mg over 6 days, with TLS prophylaxis (rasburicase and IV hydration). Responses were assessed by consensus criteria. Next generation sequencing (NGS) was performed using a custom-designed panel of 33 genes, including among others: ATM, TP53, IL2R, JAK1, JAK3, and STAT5B. CytoScan HD microarray (Affymetrix) were used to study copy number variation and or uniparental disomy. In vivo dynamic BH3 profiling (DBP) was performed on samples obtained from two patients on treatment. Results: All 15 patients were refractory or relapsing after chemotherapy (mostly bendamustine and pentostatin), except one. They were either refractory to (n=10) or ineligible (n=5) for alemtuzumab (ineligibility was decided by the treating physician based on age and comorbidities). The median age was 70 years (48-88). Within a week of starting RUX, a transient increase of the absolute lymphocyte count was observed in 66.6% of the patients. Based on the molecular status of the JAK/STAT pathway, we established 2 groups of patients. One with samples where no mutations were found (WT, n=3), and one with at least one mutation in the JAK/STAT pathway (MUT, n=12). The overall response rate (ORR) was 73.3%, with only partial responses. Five patients nearly fulfilled CR criteria except that they had persistent lymphocytosis (over 4 x 10 9/L), all of them were in the MUT group. ORR was 83.3% in the MUT group, and only one patient of the WT group obtained a PR. With a median follow-up of 73 days (22 to 368), the median progression free survival was significantly shorter in the WT group in comparison to the MUT group (1.8 months versus 5.6 months, p=0.04, Figure). Of note, four patients were treated with VEN monotherapy before the start of the combination with RUX. With that treatment, 3 of these patients achieved stable disease followed by progression within 2 to 3 months, while 1 was primary refractory to VEN monotherapy. The most frequent reported adverse events (AEs) of the RUX plus VEN combination were cytopenias, with 46.6% grade 3 or 4 thrombocytopenia and 40% grade 3 or 4 neutropenia. DBP showed that overall priming and BCL2 dependence increased in vivo (n=2) during the treatment with RUX and VEN. Finally, SNP arrays identified clonal evolution in the 3 patients evaluated sequentially (before treatment versus at progression). In one case, emergence of EZH2 and JAK1 mutation was also observed at progression using NGS. Conclusions: These preliminary results suggest promising activity of RUX plus VEN in T-PLL, and justify the development of a prospective clinical trial of this combination. Our data seem to show that this combination may be especially active for patients with JAK/STAT pathway activating mutations and that disease progression is associated with clonal evolution. Updated results will be presented at the meeting. Figure 1 Figure 1. Disclosures Herbaux: Janssen: Honoraria; Roche: Honoraria; Abbvie: Honoraria, Research Funding; Takeda: Honoraria, Research Funding. Lemonnier: Gilead: Other: travel grant; Institut Roche: Research Funding. Laribi: Jansen: Research Funding; AstraZeneca: Other: Personal Fees; Takeda: Other: Personal Fees, Research Funding; Novartis: Other: Personal Fees, Research Funding; Astellas Phama, Inc.: Other: Personal Fees; IQONE: Other: Personal Fees; AbbVie: Other: Personal Fees, Research Funding; Le Mans Hospital: Research Funding; BeiGene: Other: Personal Fees. Moreaux: Diag2Tec: Consultancy. Morschhauser: Janssen: Honoraria; Servier: Consultancy; Incyte: Membership on an entity's Board of Directors or advisory committees; Epizyme: Consultancy, Membership on an entity's Board of Directors or advisory committees; AbbVie: Consultancy, Membership on an entity's Board of Directors or advisory committees; Celgene: Membership on an entity's Board of Directors or advisory committees; AstraZenenca: Membership on an entity's Board of Directors or advisory committees; BMS: Consultancy, Membership on an entity's Board of Directors or advisory committees; Chugai: Honoraria; Genentech, Inc.: Consultancy; Gilead: Consultancy, Membership on an entity's Board of Directors or advisory committees; Novartis: Consultancy, Membership on an entity's Board of Directors or advisory committees; Roche: Consultancy, Speakers Bureau; F. Hoffmann-La Roche Ltd: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Genmab: Membership on an entity's Board of Directors or advisory committees. Davids: Ascentage Pharma: Consultancy, Research Funding; MEI Pharma: Consultancy, Research Funding; Merck: Consultancy; Eli Lilly and Company: Consultancy; Adaptive Biotechnologies: Consultancy; Pharmacyclics: Consultancy, Research Funding; BMS: Consultancy, Research Funding; Research to Practice: Consultancy; BeiGene: Consultancy; Surface Oncology: Research Funding; Verastem: Consultancy, Research Funding; TG Therapeutics: Consultancy, Research Funding; Takeda: Consultancy; Astra-Zeneca: Consultancy, Research Funding; Novartis: Consultancy, Research Funding; Celgene: Consultancy; AbbVie: Consultancy; Genentech: Consultancy, Research Funding; Janssen: Consultancy; MEI Pharma: Consultancy. Ysebaert: Abbvie, AstraZeneca, Janssen, Roche: Other: Advisory Board, Research Funding. OffLabel Disclosure: Ruxolitinib and venetoclax are used offlabel for patients refractory to current therapeutic options, based on preclinical data.

Abstract: Background. POEMS syndrome is a rare form of B cell dyscrasia combining a proliferation usually of plasma cells, a polyneuropathy, osteocondensing bone lesions and multiple other clinical signs. The pathogenesis is not well understood but VEGF plays a major role. In patients with one or two sclerotic plasmacytoma and no bone marrow involvement, first line therapy should include radiation. For patients with diffuse sclerotic lesions, bone marrow involvement or absence of any bone lesion and for those who have not demonstrated stabilization of their disease 3 to 6 months after completing radiation systemic therapy is indicated, the most effective being high dose chemotherapy with autologous stem cell transplant (ASCT). Radiation of a single lesion is effective in about every other case and is accompanied by a fairly slow improvement of the neurological symptoms, often after initial worsening. ASCT seems to be accompanied by a number of important complications, in particular engraftment syndrome. Outside these 2 treatments there is no consensus therapy. Lenalidomide (LEN), a drug without serious neurological toxicity, has the advantage of being both anti-angiogenic and cytotoxic to malignant plasma cells (Richardson PG, Blood 2002;100(9):3063-7). We have recently reported a series of 20 French patients with POEMS syndrome treated by LEN with a good efficacy. We now report the first 27 patients of a prospective phase II trial using LEN + dexamethasone (LEN-DEX), 2 cycles preceding radiation or high dose treatment trying to obtain a rapid clinical response and to avoid engraftment syndrome or 9 cycles followed by 1 year LENalone in patients who cannot receive radiation or ASCT. Methods. Newly diagnosed or relapsing patients with POEMS syndrome who needed to be treated were eligible. Patients who can be treated by local radiation or intensive treatment with stem cell support receive two 28 day cycles of LEN 25 mg PO Days 1-21 and DEX 40 mg PO Days 1,8,15,22 before radiation or intensive treatment (Group 1), the other patients receive 9 cycles of the same LEN-DEX (Group 2) and then 12 cycles of continuous low dose LEN (10 mg). LEN dose was tapered to 10 mg for patients with a creatinine clearance between 30 and 50 ml/min and DEX to 20 mg for patients above 75 years of age and for those who were frail patients. Main eligibility criteria included a diagnosis of POEMS syndrome according to criteria by Dispenzieri et al (Am J Hematol 2012;87(8):804-14), an age of 18 or more, a creatinine clearance above 30 ml/min, no prior treatment with or contraindication to LEN and no uncontrolled thrombosis. Serum and plasma VEGF, serum electrophoresis, immunofixation and free light chain measurements were centrally monitored. Neurologic evaluations were performed using the Overall Neuropathy Limitations Scale (ONLS), the Neurological Impairment Scale (NIS) and the 10 meter walk test (10MWT). The primary endpoint was evaluation of the effectiveness of LEN-DEX combination using biological responses (decrease of monoclonal protein and serum VEGF level) and secondary endpoints were clinical and particularly neurological responses. Results. Twenty-seven patients have been included in 12 centres, median age was 61 (range 32-75), the median follow-up was 6.6 months (range 2-24). Eighteen patients were in group 1, with radiotherapy in 10 patients and ASCT in 8 patients; 9 patients were in group 2. Nineteen patients were in first line and 8 already treated. Only 2 patients experienced grade 3-4 adverse events due to LEN (cytopenia) and 2 patients had allergic rashes, no thrombotic event occurred. No engraftment syndrome was noted in the 5 patients already treated with ASCT. To date, no patient have died. Evolution of VEGF median values in serum and plasma, M-spike and dFLC levels and evolution of neurological measurements are reported in table 1. Neurological improvement was very rapid in some patients, using ONLS and 10MWT 11/18 evaluable patients had a neurological improvement after 2 cycles with an improvement of 1 or more of the ONLS score and/or change of 0.1 m/s or more in the 10MWT. Only one patient who progressed after nine cycles received another therapy. Conclusion. This is the first prospective trial of LEN-DEX in POEMS syndrome. This combination seems well tolerated in this disease with a good efficacy on VEGF measurements and rapid neurological improvement in the majority of patients. Updated data will be presented at the meeting. Figure 1 Figure 1. Disclosures Jaccard: Celgene: Drug supply to Trial Other. Tournilhac:mundipharma: Honoraria, Other, Research Funding; GSK: Honoraria, Other, Research Funding; Roche: Honoraria, Other, Research Funding. Moreau:celgene: Honoraria, Membership on an entity's Board of Directors or advisory committees.

Abstract: Despite improvement in treatment strategies, virtually all chronic lymphocytic leukemia (CLL) patients will relapse and experience tumor resistance. The 17p deletion resulting in loss of the TP53 gene, found in up to 20-40% of relapsing patients, is strongly associated with impaired response to genotoxic agents, reduced progression free survival and poor overall survival. The 17p deletion usually coincides with TP53 mutation, leading to the impairment of the p53-associated pathway. In addition, sole TP53 mutations (without 17p deletion) appear also associated with poor outcome in prospective trials. However, TP53 mutation screening is time consuming, can be not exhaustive, and the respective impact of different patterns of TP53 gene impairment on p53 function and prognostic remains unclear. We previously developed a functional assay to detect p53 dysfunction (Le Garff-Tavernier, 2011) and we aim to validate this analysis on a large prospective trial. Clinical and laboratory data were collected from CLL patients (pts) enrolled in the ICLL001 – BOMP phase II trial of the French CLL intergroup (NCT01612988) evaluating a prephase of ofatumumab (300 mg) followed by 6 monthly courses of BOMP including bendamustine (70 mg/m2 d1-2), ofatumumab 1000 mg TD (d1 and d15 on 1st and 2nd courses) and high dose methylprednisolone (1 g/m2 d1-3) in fit patients with relapsing CLL and IWCLL treatment criteria. In addition to conventional screening, we focused on p53 evaluation. FISH analysis for 17p deletion was done with a 10% cut-off for positive result, TP53 gene mutation screening was performed using Sanger sequencing of the entire coding region (exons 2–11) and the p53 functional status in CLL cells was determined by a flow cytometry assay based on induction of p53 and p21 protein expression after etoposide and nutlin-3a exposition. Data from the first 55 enrolled pts are available. Sex ratio M/F was 3.3 and median age was 63.8 yrs (44.6-76.4). CLL diagnostic had been done 7,2 (1,9-16,8) years before inclusion. All patients had according to IWCLL criteria an active disease of Binet stage of A (11%), B (57%) and C (32%) respectively. Patients had been previously pretreated with a median of 1 (1-3) lines, including FCR (or FCR-like) in 51 (93%) pts and 22 (42%) pts had experienced high-risk relapses within 24 months post-FCR, with 7 (13%) pts being fludarabine refractory (less than PR after fludarabine regiment and/or response lasting less than 6 months). IGVH gene status was unmutated in 90%, elevated β2-microglobulin ( 〉 4) was found in 52%. Karyotypes were complex (≥ 3 abnormalities) in 18/46 (39%) successful cases. Using FISH, we found 15/55 (27%) del17p (median of positive cells 71%, range 10-98), 6/55 (11%) tri12, 18/55 (33%) del11q, 35/55 (64%) del13q. Results of p53 functional assay was available for 52 pts with the following results: normal in 31 pts and abnormal in 21 pts including type A (n=4), type B (n=13) and type C (n=4) dysfunction. Mutation screening was available in 55 pts. No mutation were detected in 38 pts, one significant mutation was detected in 14 pts within exon 5 (n=1), exon 6 (n=2), exon 7 (n=2), exon 8 (n=6), exon 10 (n=1) and intronic splice site (n=2) ; 3 pts had 2 mutations within exons 7 and 8 (n=1), exons 7 and 10 (n=1), exons 5 and 7 (n=1). Among the 52 pts with available functional results we found the 7 following groups (Table). In this study, the sensitivity and specificity of the p53 functional test to detect patient with 17p deletion and/or TP53 mutation was 89.5% (66.9 –99.7) and 87.9% (71.8 – 96.6) respectively. Response to p53/21 functional assay 17p deletion TP53 mutation n % Group 1 Normal No No 29 56 Group 2 Abnormal Yes Yes 13 25 Group 3 Abnormal Yes No 1 2 Group 4 Abnormal No Yes 3 5.5 Group 5 Abnormal No No 4 7.5 Group 6 Normal Yes No 1 2 Group 7 Normal No Yes 1 2 This study shows that an in vitro p53 functional analysis can predict with an acceptable sensitivity the presence of TP53 gene disruption and could be useful to identify pts with TP53 mutation without 17p deletion. Interestingly, this functional assay coupled with cytogenetic and mutational screening could reveal 3 sub-groups of pts with potential clinical consequences: i) normal p53 function despite a del17p deletion (group 6) ii) normal p53 function despite a TP53 mutation (group 7) and in contrast iii) abnormal p53 function without any TP53 gene disruption (group 5) allowing to describe alternative alterations of p53 pathway. Disclosures: Dilhuydy: Roche: Honoraria. Leblond:Roche: Consultancy, Honoraria, Membership on an entity’s Board of Directors or advisory committees, Speakers Bureau; Janssen: Honoraria, Membership on an entity’s Board of Directors or advisory committees; Mundipharma: Honoraria, Membership on an entity’s Board of Directors or advisory committees, Speakers Bureau. Feugier:Roche: Honoraria, Membership on an entity’s Board of Directors or advisory committees. Tournilhac:MUNDIPHARMA: Consultancy, travel funding Other; GSK: Consultancy, travel funding, travel funding Other; Celgene: Consultancy, teaching, teaching Other.

Abstract: Reduced-intensity conditioning (RIC) regimens are increasingly used for allogeneic stem cell transplantation (allo-SCT). RIC has been shown to allow engraftment with minimal early transplantation-related mortality (TRM). However, in the context of RIC, predictive factors for acute and chronic graft-versus-host disease (aGVHD and cGVHD, respectively) and their effect on outcome remain unknown. In this report, we analyzed the outcome of 101 high-risk patients (70 hematologic and 31 nonhematologic malignancies) who received an HLA-identical sibling allo-SCT after RIC, including fludarabine, busulfan, and antithymocyte globulin (ATG). The cumulative incidence of grade II-IV aGVHD was 36% (95% confidence interval [CI], 27%-45%), whereas the cumulative incidence of cGVHD at 2 years was 43% (95% CI, 33%-53%). In multivariate analysis, the incidence of aGVHD was significantly associated with the ATG dose infused during conditioning (P = .0005), whereas peripheral blood as stem cell source was the only predictive factor for the development of cGVHD (P = .0007). The 1-year cumulative incidences of disease progression or relapse in patients with (n = 69) and without (n = 31) GVHD (whatever its form or grade) were 30% (95% CI, 19%-41%) and 55% (95% CI, 37%-72%), respectively (P = .02), suggesting that a potent graft-versus-tumor (GVT) effect can be achieved in high-risk patients following RIC. Moreover, the GVT effect was closely associated with GVHD without an increased risk of TRM (cumulative incidence of TRM, 18% [95% CI, 10%-25%] ). Collectively, these results provide a framework for the refinement of RIC approaches designed to enhance the GVT effect with an acceptable risk of GVHD.

Abstract: Abstract 2392 Mantle cell lymphoma (MCL) is an aggressive and rare B-cell lymphoma entity representing around 5–8% of non-Hodgkin's lymphomas (NHLs) in adults. The hallmark of MCL is the t(11;14) which promotes cycline D1 overexpression. In France as in several European countries, autologous stem cell transplantation (ASCT) is the standard care for young MCL patients. Some recent prospective trials have suggested that ASCT could be a curable treatment for a subgroup of MCL patients. However, additional studies with long term follow-up (FU) are needed in order to confirm or not this statement. The present study is a retrospective analysis conducted on behalf of the Société Française de Greffe de Moëlle et de Thérapie Cellulaire (SFGM-TC). We aimed to investigate the outcome of MCL patients who underwent ASCT and parameters that influence both OS and EFS. All transplanted MCL patients recorded in the SFGM-TC database were eligible for the present study. Participating centers were asked to confirm the MCL diagnosis, to update biological and clinical parameters and FU. Five hundred files have been analyzed to date. The number of ASCT for MCL patients increased during the last years with 144 patients transplanted from 2003 to 2005 as compared to only 149 patients prior 2003. Since 2003, around 50 MCL patients per year undergo ASCT in France. Patients'characteristics: sex gender was male in 79.2%. At time of diagnosis, 134 patients (26.8%) were 〈 50 years old and 128 (25.6%) were 〉 59 years old. More than half of the patients had a stage IV disease. The majority of these patients underwent ASCT upfront (78.8%; n=394). The conditioning regimens were BEAM (32%), TBI/Aracytin/Melphalan (TAM) (10.6%), TBI/melphalan (10.2%) or TBI/cyclophosphamide (13.2%) (data missing=156). The use of TBI for transplant conditioning decreased from 56% before 2003 to 39% after. Regarding patient outcomes, the medium FU for living patients is 34.4 months. The median EFS rate calculated after ASCT is 49.7 months and 191 experienced relapse or progression. The 3- and 5- year EFS estimates are 63.3% and 44.8%, respectively. One hundred thirty patients died and the median OS is 99 months. The 3- and 5- year OS estimates are 79.5% and 68.2%, respectively. Both EFS and OS curves show no plateau and late relapses have been reported more than 7 years after ASCT. Among patients with at least one year of FU (n=380), a secondary malignancies is reported in 27 cases (7%). In the group of patients who underwent ASCT upfront, the median EFS and OS duration are 58.8 and 114 months, respectively. For these patients (n=394), a blastic variant (p=3.10-5; p=.01), a Ki67 staining 〉 30 (p=.01; p=.01), ECOG PS 〉 2 (p=5.10-5; p=.01) and a high-risk MIPI (p=.003; p=.003) are adverse parameters that impact both EFS and OS, respectively. High-risk age-adjusted IPI have also an adverse prognostic impact on EFS (p=.001). At relapse, 25 patients underwent allogeneic stem cell transplantation and 19 (76%) obtained at least a partial response. This large retrospective analysis is ongoing and still represents one of the most important series of transplant MCL patients. Disclosures: No relevant conflicts of interest to declare.