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In previously untreated, medically fit patients with chronic lymphocytic leukemia, research is focused on developing fixed-duration strategies to improve long-term outcomes whilst sparing patients from serious toxicities. The ICLL-07 trial evaluated a fixed-duration (15-month) immunochemotherapy approach where, following obinutuzumab-ibrutinib induction for 9 months, patients (n=10) in complete remission (CR) with bone marrow (BM) measurable residual disease (MRD)

Waldenström's disease is a B-cell neoplasm characterized by the accumulation of lymphoplasmacytic cells (LPCs) in the bone marrow, and more rarely in the lymph nodes and the spleen, which produce a monoclonal immunoglobulin M (IgM) protein. The diagnosis requires the identification of LPCs in the bone marrow, using specific markers in flow cytometry. The MYD88L265P mutation is found in 95% of cases and the CXCR4 mutation in 30-40% of cases. These markers must be sought because they have a diagnostic and prognostic role, and they might become predictive in the future. The clinical presentation is very variable, and includes anomalies related to the bone marrow infiltration of the LPCs (such as anemia), but also anomalies of the physico-chemical and/or immunological activity of the overproduced IgM (hyperviscosity, AL amyloidosis, cryoglobulinemia, anti-MAG neuropathies, etc.). Prognostic scores (IPSSWM) now make it possible to understand the prognosis of symptomatic WM requiring appropriate treatment. The therapeutic management depends on many parameters, such as the specific clinical presentation, the speed of evolution and of course the age and comorbidities. Immuno-chemotherapy is often the 1st line treatment (rituximab-cyclophosphamide-dexamethasone (RCD) or bendamustine-rituximab (BR)) but the role of targeted therapies is becoming preponderant. Bruton tyrosine kinase inhibitors (BTKi) are used today in first relapse. Other therapeutic perspectives will certainly allow us tomorrow to better understand this incurable chronic disease, such as new generations of BTKi, BCL2 inhibitors, anti-CXCR4, bi-specific antibodies, and CAR-T cells.

The FIRE study investigated the real-world effectiveness and safety of ibrutinib in prospectively observed patients with chronic lymphocytic leukemia (CLL)/small lymphocytic lymphoma (SLL) and mantle cell lymphoma (MCL) in France. Patients were mostly relapsed/refractory with high-risk features. First-line CLL/SLL patients had del17p and/or TP53 mutations. In this interim analysis, the median follow-up time for patients with CLL/SLL and MCL was 17.7 and 15.1 months, respectively. In the effectiveness populations for CLL/SLL (n = 200) and MCL (n = 59), the median progression-free survival was not estimable and 12.4 months, respectively; the 12-month overall survival rates were 88.5% and 65.8%, respectively. Treatment-emergent adverse events of interest for patients with CLL/SLL (n = 202) and MCL (n = 59) included: infections and infestations (53.5% and 32.2%), major bleeding (5.0% and 5.1%), and atrial fibrillation (5.9% and 8.5%); 135 (66.8%) and 20 (33.9%) patients were continuing treatment at the time of data cutoff. Future analyses will report on longer-term follow-up (Trial registration: ClinicalTrials.gov, NCT03425591. Registered 1 February 2018—Retrospectively registered, https://clinicaltrials.gov/ct2/show/NCT03425591).

International audience; Cytarabine-based immuno-chemotherapy followed by autologous stem cell transplantation (ASCT) consolidation is standard of care for fit patients with Mantle Cell Lymphoma (MCL). BEAM (Carmustine, Etoposide, Aracytine, Melphalan) is among the most frequently used conditioning regimen. Studies comparing BEAM with Bendamustine-EAM (BeEAM) have suggested that patients treated with BeEAM have a better progression-free survival (PFS). We performed a cross-study analysis to better evaluate BeEAM. Thirty-five patients from a retrospective study who received R-DHAP/BeEAM were compared to 245 patients from the LyMa trial (NCT00921414) who all received R-DHAP followed by R-BEAM. PFS and Overall Survival (OS) were estimated using Kaplan-Meier methods. At 2 years there was no difference between R-BEAM and BeEAM in either PFS (84.9% versus 87.9%; p = 0.95) or OS (91.8% versus 94.2%; p = 0.30). Analyses were repeated on a propensity score to reduce biases. Each patient from the BeEAM cohort (n = 30) was matched to three patients from the R-BEAM cohort (n = 90) for age, sex, MIPI score, pre-transplant status disease and rituximab maintenance (RM). PFS and OS at 2 years remained similar between R-BEAM and BeEAM with more renal toxicity in BeEAM group. MCL patients who received R-DHAP induction before ASCT have similar outcome after R-BEAM or BeEAM conditioning regimen.

Immunocompromised individuals such as patients with chronic lymphocytic leukemia (CLL) are at risk of impaired immune responses to vaccination. The objective of our study was to evaluate severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)–specific antibody responses in patients with CLL after the first, second, and third doses of the BNT162b2 or mRNA-1273 vaccines and after a single dose for patients with confirmed previous COVID-19. In all, 530 patients were included in the study. Patients received 2 doses at a 4-week interval and a third dose if they were seronegative after the second dose. Response rate was 27% after dose 1 and 52% after dose 2. Post-dose 2 treatment-naïve patients had the highest response rate (72%) followed by patients previously treated by chemoimmunotherapy (60%). Among patients receiving therapy, those receiving Bruton tyrosine kinase inhibitor alone (22%) or in combination with anti-CD20 monoclonal antibodies or venetoclax (0%) had the poorer response rate whereas patients who received venetoclax monotherapy achieved a significantly higher response rate (52%). A multivariable analysis identified age older than 65 years, ongoing CLL treatment, and gamma globulin ≤6 g/L as independent predictors of the absence of seroconversion. Post-dose 2 seronegative patients had a global response rate of 35% after dose 3. This study provides an argument for the use of a third dose and for prophylactic SARS-CoV-2 neutralizing monoclonal antibodies.

The impact of a third dose of COVID-19 vaccine on antibody responses is unclear in immunocompromised patients. The objective of this retrospective study was to characterize antibody responses induced by a third dose of mRNA COVID-19 vaccine in 160 kidney transplant recipients and 20 patients treated for chronic lymphocytic leukemia (CLL). Prevalence of anti-spike IgG ≥ 7.1 and ≥ 30 BAU/mL after the third dose were 47% (75/160) and 39% (63/160) in kidney transplant recipients, and 57% (29/51) and 50% (10/20) in patients treated for CLL. Longitudinal follow-up identified a moderate increase in SARS-CoV-2 anti-spike IgG levels after a third dose of vaccine in kidney transplant recipients (0.19 vs. 5.28 BAU/mL, p = 0.03) and in patients treated for CLL (0.63 vs. 10.7 BAU/mL, p = 0.0002). This increase in IgG levels had a limited impact on prevalence of anti-spike IgG ≥ 30 BAU/mL in kidney transplant recipients (17%, 2/12 vs. 33%, 4/12, p = 0.64) and in patients treated for CLL (5%, 1/20 vs. 45%, 9/20, p = 0.008). These results highlight the need for vaccination of the general population and the importance of non-medical preventive measures to protect immunocompromised patients.

International audience; Dasatinib is a second-generation BCR-ABL1 tyrosine kinase inhibitor approved for patients with chronic myeloid leukaemia (CML). Dasatinib 100 mg per day is associated with an increased risk of pleural effusion (PlEff). We randomly evaluated whether therapeutic drug monitoring (TDM) may reduce dasatinib-associated significant adverse events (AEs) by 12 months (primary endpoint). Eligible patients started dasatinib at 100 mg per day followed by dasatinib (C)min assessment. Patients considered overdosed [(C)min ≥ 3 nmol/l) were randomised between a dose-reduction strategy (TDM arm) and standard of care (control arm). Out of 287 evaluable patients, 80 patients were randomised. The primary endpoint was not met due to early haematological AEs occurring before effective dose reduction. However, a major reduction in the cumulative incidence of PlEff was observed in the TDM arm compared to the control arm (4% vs. 15%; 11% vs. 35% and 12% vs. 39% at one, two and three years, respectively (P = 0·0094)). Molecular responses were superimposable in all arms. Dasatinib TDM during treatment initiation was feasible and resulted in a significant reduction of the incidence of PlEff in the long run, without impairing molecular responses. (NCT01916785; https://clinicaltrials.gov).

International audience

The BCL2 inhibitor venetoclax is transforming the management of patients with chronic lymphocytic leukemia (CLL), given its high efficacy in relapsed/refractory CLL as observed in both early-phase and randomized clinical trials. The present study aimed to determine whether venetoclax is effective and well tolerated in patients with CLL or Richter's syndrome (RS) in a real-world setting and to highlight factors impacting survival. Data from a venetoclax French compassionate use program were collected for 67 patients (60 with CLL and 7 with RS). Most patients presented adverse genetic features, such as TP53 disruption (74%) or complex karyotype (58%). Tumor lysis syndrome was observed in 14 (22%) patients, and 16 (24%) patients were hospitalized for grade III/IV infection. In the CLL cohort, ORR was 75 %, 1-year PFS was 61% (95% CI = 47-72%) and 1-year OS 70% (95% CI = 56-80%). No impact of TP53 disruption was noted while complex karyotype was identified as a predictor of both inferior PFS (HR = 3.46; 95% CI = 1-12; log-rank p = 0.03) and OS (HR = 3.2; 95% CI = 0.9-11.4, log-rank p = 0.047). Among the seven patients with RS, two achieved an objective response to venetoclax; however, the median OS was only 1.1 month. The well-balanced safety/efficacy profile of venetoclax is confirmed in this real-world setting. Complex karyotype should be evaluated as a predictive factor of survival for patients treated by venetoclax.

The coexistence of dual hematological neoplasms is very rare. Sequential or synchronous neoplasms in hematology are an uncommon and complex clinical situation. The aim of the Hemo2 study was to describe the clinical characteristics and analyze the outcome of these patients. We performed a retrospective review of all patients diagnosed with sequential or synchronous hematological malignancies in the university hospital of Tours, between 2007 and 2018. We identified 49 patients in our study, with a prevalence of 0.89%. Sequential and synchronous combinations were found in 36 (73%) and 13 (27%) patients, respectively. One patient presented three sequential neoplasms. The median cumulative incidence was 6 years (95% CI 3–7). Among all neoplasms diagnosed (n = 99), we found 79 lymphoid neoplasms (LNs) (80%) and 20 myeloid neoplasms (MNs) (20%). Sex ratio was 1.88 with 65% of males and 35% of females. The most common LNs were Hodgkin lymphoma (n = 16; 16%) and multiple myeloma (n = 11; 11%). The most frequent MN was essential thrombocythemia (n = 5; 5%). The most common combination was Hodgkin lymphoma and follicular lymphoma in five (10%) patients. The overall survival from the first diagnosis (OS1) at 5 years was 82.4% (95% CI 72.1–94.3). The median overall survival from the second diagnosis (OS2) was 98 months (95% CI 44–NR) and 5-year OS2 was 58.7% (95% CI 45.5–75.7). Median progression-free survival from the second diagnosis (PFS) was 47 months (95% CI 27–NR) with 5-year PFS of 49% (95% CI 35.9–67). OS and PFS did not statistically differ between synchronous and sequential dual neoplasms. In this cohort, that the death relative risk (RR) was significantly lower if the second neoplasm appeared after more than 4 years following the first diagnosis (OR 0.37 (95% CI 0.16–0.90)). The Hemo2study confirmed the rarity of dual hematological neoplasms. In this cohort, HL and FL were the most frequent combinations. Our results may support that synchronous and sequential dual neoplasms bear the same prognosis. Further studies are needed to better characterize these uncommon clinical situations.

Richter syndrome (RS) occurs during the disease course of 2 to 10% of Chronic Lymphocytic Leukemia (CLL). Diffuse Large B-Cell Lymphoma (DLBCL) subtype accounts for 90-95% of RS cases. While presenting with the same morphology as de novo DLBCLs, DLBCL subtype of RS is associated with a very poor outcome. Proteins are the primary cellular biological effectors. Proteome composition is highly dependent on regulatory mechanisms located both upstream and downstream translation (transcriptional regulation, post-translational modifications, protein metabolism). Thus, the analysis of the genome and the transcriptome only allows a putative extrapolation of the expressed proteome. Proteomic studies have been performed in the context of de novo DLBCLs (Fornecker et al. Sci Rep. 2019), unravelling a set of proteins associated with refractoriness. In CLL, it showed different profiles according to IGHV mutational status after B-Cell Receptor activation (Perrot et al. Blood 2011). No proteomic study of RS has been carried out to date. RS sample selection was performed across 7 French institutions affiliated to the FILO (French Innovative Leukemia Organization). A total of 49 fresh frozen biopsies were collected, including 28 de novo DLBCLs and 21 RS, mostly treated with first line R-CHOP. All biopsies were centrally reviewed. RS samples were characterized, with data on CLL-RS clonal relationship and mutational status for a 13-gene panel representing the most frequently mutated genes in CLL. Only DLBCL subtype RS samples with at least 50% tumor purity (range 50-95%) and a minimum 10 mg weight were selected. Peptide measurements were performed using liquid chromatography coupled with tandem mass spectrometry, according to published methods (Muller et al. Sci Rep. 2018). Stringent quality controls were applied to ensure sample integrity, abundance accuracy and overall reproducibility. Proteome reconstruction at peptide and at protein level was achieved with a specifically devised pipeline involving conditional filtering, full normalization, categorization and imputation of missing values. These tools made use of the R/Bioconductor DEP package (Zhang et al. Nat Protoc. 2018). Supervised (Bayesian linear models) and unsupervised (hierarchical clustering, K-means, PCA) analyses were further applied to identify differential protein signatures. These were functionally annotated with ReactomePA (Yu et al. Mol Biosyst. 2016) for pathways and STRING (Szklarczyk et al. Nucleic Acids Res. 2019) for association networks. Extended proteomics analysis identified 1,772 proteins, among which 191 were differentially expressed (False Discovery Rate/FDR < 0.05) in RS samples compared to de novo DLBCLs, with 82 increased and 109 decreased proteins. Hierarchical clustering revealed a highly correlated expression profile of these top candidates and clearly separated the 21 RS and the 28 de novo DLBCL samples (Figure 1). Sample distribution was independent from chemosensitivity/resistance, for DLBCL samples, and also unrelated to GCB/Non-GCB phenotype according to Hans algorithm, Epstein-Barr virus positivity or tumor purity. Functional interactome is an in silico protein-protein interaction network built on published data from the literature and available in public databases. The functional interactome computed from the 82 proteins overexpressed in RS showed a strongly enriched association network (protein-protein interactions; p-value < 1e-16), with an over-representation in BCR pathway, VEGF signaling, JAK-STAT pathway and Interleukin-12, Rho GTPase, and actin coiling (FDR < 0.05; Figure 1). Proteins underexpressed in RS (109) also displayed highly associated interactions (p-value < 1e-16) with a main node including proteins involved in cell death regulation, extracellular matrix organization, regulation of Insulin Growth Factor, and signaling by receptor tyrosine kinase (FDR < 0.05; Figure 1). Here we performed proteomics on a 49-sample cohort of 28 de novo DLBCLs and 21 RS, which revealed a specific and differential signature in RS. This includes increased expression of targets within the druggable signaling pathways BCR and JAK-STAT. Furthermore the decrease in proteins involved in cell death regulation and extracellular matrix organization suggests resistance mechanisms to apoptosis and immune system in RS. Disclosures Dartigeas: Janssen: Honoraria; Roche: Honoraria; Gilead: Other: non-financial support. Tausch:AbbVie: Consultancy, Honoraria, Research Funding; Roche: Consultancy, Honoraria, Research Funding; Janssen-Cilag: Consultancy, Honoraria, Research Funding. Leblond:AstraZeneca: Consultancy, Honoraria; Lilly: Consultancy; Janssen: Consultancy, Honoraria, Research Funding, Speakers Bureau; Amgen: Honoraria; Gilead: Honoraria, Speakers Bureau; AbbVie: Consultancy, Honoraria, Other: Travel/accommodations/expenses, Research Funding, Speakers Bureau; Roche: Consultancy, Honoraria, Other: Travel/accommodations/expenses, Research Funding, Speakers Bureau. Thieblemont:Hospira: Research Funding; Amgen: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: TRAVEL, ACCOMMODATIONS, EXPENSES (paid by any for-profit health care company); Bristol-Myers Squibb: Consultancy, Other: TRAVEL, ACCOMMODATIONS, EXPENSES (paid by any for-profit health care company); Cellectis: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: TRAVEL, ACCOMMODATIONS, EXPENSES (paid by any for-profit health care company), Speakers Bureau; Roche: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: TRAVEL, ACCOMMODATIONS, EXPENSES (paid by any for-profit health care company), Research Funding; Celgene: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: TRAVEL, ACCOMMODATIONS, EXPENSES (paid by any for-profit health care company); Incyte: Honoraria; Kite, a Gilead Company: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: TRAVEL, ACCOMMODATIONS, EXPENSES (paid by any for-profit health care company); Novartis: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: travel support; AbbVie: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: TRAVEL, ACCOMMODATIONS, EXPENSES (paid by any for-profit health care company); Bayer: Honoraria. Stilgenbauer:Mundipharma: Consultancy, Honoraria, Other, Research Funding; Novartis: Consultancy, Honoraria, Other, Research Funding; Pharmacyclics: Consultancy, Honoraria, Other, Research Funding; Gilead: Consultancy, Honoraria, Other: travel support, Research Funding; Genentech: Consultancy, Honoraria, Other: travel support, Research Funding; Genzyme: Consultancy, Honoraria, Other: travel support, Research Funding; F. Hoffmann-LaRoche: Consultancy, Honoraria, Other: travel support, Research Funding; Celgene: Consultancy, Honoraria, Other: travel support, Research Funding; Boehringer-Ingelheim: Consultancy, Honoraria, Other: travel support, Research Funding; GlaxoSmithKline: Consultancy, Honoraria, Other: travel support, Research Funding; Amgen: Consultancy, Honoraria, Other: travel support, Research Funding; AbbVie: Consultancy, Honoraria, Other: travel support, Research Funding; Janssen-Cilag: Consultancy, Honoraria, Other: travel support, Research Funding. Guieze:abbvie: Honoraria, Other: advisory board, travel funds; janssen cilag: Honoraria, Other: advisory board, travel funds; roche: Other: travle funds; gilead: Honoraria, Other: travel funds; astrazanecka: Honoraria, Other: advisory board. Perrot:Amgen, BMS/Celgene, Janssen, Sanofi, Takeda: Consultancy, Honoraria, Research Funding. Feugier:astrazeneca: Consultancy, Honoraria, Research Funding; abbvie: Consultancy, Honoraria, Research Funding; roche: Consultancy, Honoraria, Research Funding; gilead: Consultancy, Honoraria, Research Funding; janssen: Consultancy, Honoraria, Research Funding. Broséus:AstraZeneca: Consultancy, Honoraria; Janssen: Honoraria, Research Funding; Novartis: Honoraria, Research Funding; Gilead: Honoraria.

Richter Syndrome (RS) corresponds to the transformation of Chronic Lymphocytic Leukemia (CLL) or Small Lymphocytic Lymphoma (SLL) into an aggressive lymphoma, in most cases a Diffuse Large B-Cell Lymphoma (DLBCL). RS outcome is variable and still poorly understood. The aim of our study was to analyze the clinical, biological and molecular features liable to predict survival in a retrospective series of newly diagnosed RS from the French Innovative Leukemia Organization (FILO). From 10 French centers, 103 biopsy-confirmed DLBCL subtype RS, diagnosed from 2001 to 2019, were identified. Fresh-frozen biopsies (FB) were available in 58 cases. All biopsies were centrally reviewed. Clinical and biological characteristics at CLL and RS diagnoses including cytogenetics, clonal relationship with the pre-existing CLL, Epstein-Barr virus (EBV) status, cell of origin (COO) according to the Hans algorithm, RS prognostic scores (Tsimberidou et al. J Clin Oncol. 2006, Rossi et al. Blood 2011) as well as treatment and outcomes were collected. Targeted next generation sequencing was used on RS FB for the following gene set: TP53, ATM, SF3B1, NOTCH1, BIRC3, FBXW7, RPS15, EGR2, MYD88, XPO1, POT1, BRAF, and NFKBIE. Overall Survival (OS) was defined as time from RS diagnosis until the date of death or end of follow-up and analyzed using Kaplan-Meier method. Multivariable analysis was performed using Cox regression model for variables with a p-value Clinical and biological characteristics and outcomes were broadly similar between the full 103-patient cohort and the subset of 58 patients with available gene mutation data. The latter only was considered for the subsequent analyses. The median age at CLL/SLL diagnosis was 60 (range 34-81) and 39 patients (67.2%) were male. Prior to RS, 24 (41.38%) received more than 1 line of treatment for CLL. The median time to transformation was 5 years (range 0-22). The median OS from RS diagnosis was 8 months (Figure 1a). The median age at RS diagnosis was 65.5 years (range 42-87). ECOG Performance Status (PS) was >1 in 29/53 patients (54.8%) and 32/56 (57.1%) had a Bulky disease. Elevated Lactate DeHydrogenase (LDH) levels (≥ 1.5N) were found in 38/49 patients (77.6%). Unmutated IGHV was observed in 45/58 (77.6%) RS samples. CLL and RS were clonally related for 29/33 (87.9%) RS with available IGHV sequence at CLL diagnosis. TP53 disruption was detected in 34/56 (60.7%) RS cases including TP53 mutations in 23/58 (39.7%). According to Tsimberidou et al., 10/46 (21.7%) RS were in the low-risk group, 10 in the low-intermediate risk group, 11 (23.9%) in the high-intermediate risk group and the other 15 in the high-risk group. According to the Rossi score, only 4/51 RS (7.8%) were low risk, and 19 (37.3%) and 28 (54.9%) intermediate and high-risk, respectively. The most frequent treatment for RS was R-CHOP-like regimen [38/56 (67.9%)], 5 and 2 patients received autologous or allogeneic stem cell transplantation respectively. Most patients, 40/56 (71.4%) failed to reach complete remission after the first line. By bivariate analysis (Figure 1b-e), ECOG PS, platelet count and TP53 disruption worsened OS (p1, platelet count RS outcome is poor. Here, we focused specifically on Richter cells on diagnostic biopsies for genetic analyses. Unmutated IGHV status was identified as prognostic factor for RS, in addition to the previously described: ECOG PS, platelet count and TP53 disruption. More molecular studies are necessary to increase knowledge about RS and improve the survival of patients with DLBCL-type RS. Disclosures Dartigeas: Janssen: Honoraria; Roche: Honoraria; Gilead: Other: non-financial support. Tausch:Roche: Consultancy, Honoraria, Research Funding; AbbVie: Consultancy, Honoraria, Research Funding; Janssen-Cilag: Consultancy, Honoraria, Research Funding. Leblond:Roche: Consultancy, Honoraria, Other: Travel/accommodations/expenses, Research Funding, Speakers Bureau; AbbVie: Consultancy, Honoraria, Other: Travel/accommodations/expenses, Research Funding, Speakers Bureau; Janssen: Consultancy, Honoraria, Research Funding, Speakers Bureau; Gilead: Honoraria, Speakers Bureau; Amgen: Honoraria; AstraZeneca: Consultancy, Honoraria; Lilly: Consultancy. Thieblemont:Incyte: Honoraria; Bristol-Myers Squibb: Consultancy, Other: TRAVEL, ACCOMMODATIONS, EXPENSES (paid by any for-profit health care company); Cellectis: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: TRAVEL, ACCOMMODATIONS, EXPENSES (paid by any for-profit health care company), Speakers Bureau; AbbVie: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: TRAVEL, ACCOMMODATIONS, EXPENSES (paid by any for-profit health care company); Celgene: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: TRAVEL, ACCOMMODATIONS, EXPENSES (paid by any for-profit health care company); Amgen: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: TRAVEL, ACCOMMODATIONS, EXPENSES (paid by any for-profit health care company); Roche: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: TRAVEL, ACCOMMODATIONS, EXPENSES (paid by any for-profit health care company), Research Funding; Novartis: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: travel support; Kite, a Gilead Company: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: TRAVEL, ACCOMMODATIONS, EXPENSES (paid by any for-profit health care company); Hospira: Research Funding; Bayer: Honoraria. Laribi:abbvie: Honoraria, Research Funding; amgen: Research Funding; novartis: Honoraria, Research Funding; takeda: Research Funding. Stilgenbauer:F. Hoffmann-LaRoche: Consultancy, Honoraria, Other: travel support, Research Funding; Genentech: Consultancy, Honoraria, Other: travel support, Research Funding; Genzyme: Consultancy, Honoraria, Other: travel support, Research Funding; Gilead: Consultancy, Honoraria, Other: travel support, Research Funding; GlaxoSmithKline: Consultancy, Honoraria, Other: travel support, Research Funding; Janssen-Cilag: Consultancy, Honoraria, Other: travel support, Research Funding; Mundipharma: Consultancy, Honoraria, Other, Research Funding; Novartis: Consultancy, Honoraria, Other, Research Funding; Pharmacyclics: Consultancy, Honoraria, Other, Research Funding; Boehringer-Ingelheim: Consultancy, Honoraria, Other: travel support, Research Funding; Celgene: Consultancy, Honoraria, Other: travel support, Research Funding; Amgen: Consultancy, Honoraria, Other: travel support, Research Funding; AbbVie: Consultancy, Honoraria, Other: travel support, Research Funding. Guieze:abbvie: Honoraria, Other: advisory board, travel funds; janssen cilag: Honoraria, Other: advisory board, travel funds; roche: Other: travle funds; gilead: Honoraria, Other: travel funds; astrazanecka: Honoraria, Other: advisory board. Feugier:gilead: Consultancy, Honoraria, Research Funding; janssen: Consultancy, Honoraria, Research Funding; roche: Consultancy, Honoraria, Research Funding; abbvie: Consultancy, Honoraria, Research Funding; astrazeneca: Consultancy, Honoraria, Research Funding. Broséus:Novartis: Honoraria, Research Funding; Janssen: Honoraria, Research Funding; AstraZeneca: Consultancy, Honoraria; Gilead: Honoraria.

Introduction In previously untreated, medically fit patients with chronic lymphocytic leukaemia (CLL) and no 17p deletion, there is current research interest in improving survival outcomes and potentially sparing some patients from the standard 6 cycles of fludarabine, cyclophosphamide and rituximab (FCR). The phase II ICLL-07 (NCT02666898) trial, conducted by the French Innovative Leukemia Organization (FILO), aimed to explore the efficacy of obinutuzumab and ibrutinib treatment induction for 9 months, followed by a minimal residual disease (MRD)-driven strategy. Methods Following assessment at Month 9, patients in complete response (CR) with bone marrow (BM) MRD ResultsBetween 10/2015 and 05/2017, 135 patients were enrolled. At Month 9, only 8% of patients reached CR with BM MRD Conclusion These findings from the ICLL-07 trial demonstrated that, in previously untreated, medically fit patients with CLL and no 17p deletion, treatment induction with obinutuzumab and ibrutinib followed by an MRD-driven strategy yielded a high rate of CR with BM and PB MRD Disclosures Salles: Roche, Janssen, Gilead, Celgene: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Educational events; Amgen: Honoraria, Other: Educational events. Leblond:Gilead: Honoraria, Speakers Bureau; Abbvie: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Janssen: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Roche: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Amgen: Honoraria, Speakers Bureau; Astra Zeneca: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau. Cartron:Roche, Celgene: Consultancy; Sanofi, Gilead, Janssen, Roche, Celgene: Honoraria. Cymbalista:Sunesis: Research Funding; Roche: Research Funding; Janssen: Honoraria; Abbvie: Honoraria; AstraZeneca: Honoraria; Gilead: Honoraria. Le Garff-Tavernier:Alexion: Consultancy, Honoraria. Letestu:Alexion: Membership on an entity's Board of Directors or advisory committees, Other: speaker fee, expert contracts; Roche: Membership on an entity's Board of Directors or advisory committees, Other: speaker fee, expert contracts; Janssen: Membership on an entity's Board of Directors or advisory committees, Other: speaker fee, expert contracts; Abbvie: Membership on an entity's Board of Directors or advisory committees, Other: speaker fee, expert contracts. Feugier:janssen: Honoraria, Research Funding, Speakers Bureau; gilead: Honoraria, Research Funding, Speakers Bureau; abbvie: Honoraria, Research Funding, Speakers Bureau; roche: Honoraria, Research Funding, Speakers Bureau.

Summary Background Most patients with chronic lymphocytic leukaemia relapse after initial therapy combining chemotherapy with rituximab. We assessed the efficacy and safety of rituximab maintenance treatment versus observation for elderly patients in remission after front-line abbreviated induction by fludarabine, cyclophosphamide, and rituximab (FCR). Methods This randomised, open-label, multicentre phase 3 trial at 89 centres in France enrolled treatment-naive and fit patients aged 65 years or older with chronic lymphocytic leukaemia without del(17p). Eligible patients had an Eastern Cooperative Oncology Group performance status of 0–1 and adequate renal and hepatic function. Patients in response to complete induction treatment with four monthly courses of full-dose FCR with two interim rituximab doses on day 14 of cycles 1 and 2 (oral fludarabine [40 mg/m 2 per day] and oral cyclophosphamide [250 mg/m 2 per day] for the first 3 days of each cycle, rituximab at 375 mg/m 2 intravenously on day 0 of cycle 1 and subsequently at 500 mg/m 2 on day 14 of cycle 1, days 1 and 14 of cycle 2, and day 1 of cycles 3 and 4) were eligible for randomisation. Recovery from FCR toxicity and patient willingness to continue the trial were mandatory. We randomly assigned (1:1) patients to either receive intravenous rituximab (500 mg/m 2 ) every 8 weeks for up to 2 years or undergo observation, with a central computer-generated randomisation list using randomly permuted blocks of variable sizes. Randomisation was stratified by IGHV mutational status, the presence or absence of del(11q), and response level to induction treatment. The primary endpoint was progression-free survival, with the objective to assess the superiority of rituximab maintenance relative to observation. The final analysis was done in the intention-to-treat population. Safety was analysed in all patients who received at least one dose of study drug in the rituximab group and in all patients in the observation group. This trial is closed to accrual whilst continuing patient follow-up. The study is registered with ClinicalTrials.gov, number NCT00645606. Findings Between Dec 14, 2007, and Feb 18, 2014, 542 patients were enrolled, of whom 525 started FCR induction. Between June 10, 2008, and Aug 14, 2014, 409 (78%) patients were randomly assigned to rituximab maintenance (n=202) or observation (n=207). Four (2%) patients in the rituximab group did not receive the allocated treatment (progressive disease [n=1], adverse events [n=3]). After a median follow-up of 47·7 months (IQR 30·4–65·8), median progression-free survival in the rituximab group (59·3 months, 95% CI 49·6–not estimable) was improved compared with the observation group (49·0 months, 39·9–60·5; hazard ratio 0·55, 95% CI 0·40–0·75; p=0·0002). Neutropenia and grade 3–4 infections were more common with rituximab maintenance (105 [53%] of 198 patients vs 74 [36%] of 207 patients and 38 [19%] vs 21 [10%], respectively) during the study. The most common grade 3–4 infection was lower respiratory tract infection (24 [12%] vs eight [4%]). The incidence of second cancers, except basal cell carcinoma, was similar in both groups (29 [15%] vs 23 [11%]). Deaths were related to adverse events for 23 (11%) patients in the rituximab group and 16 (8%) in the observation group. Interpretation 2-year maintenance rituximab in selected elderly patients improves progression-free survival and shows an acceptable safety profile. Immunotherapy maintenance strategy is a relevant option in front-line treatment of chronic lymphocytic leukaemia, even in the age of targeted therapy. Funding French National Cancer Institute (INCa), Roche, Chugai.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is responsible for an ongoing global pandemic. Phase III trials have demonstrated excellent efficacies of mRNA vaccines against SARS-CoV-2 in large population studies (Baden LR, NEJM, 2021; Polack FP, NEJM, 2020). Immunosuppressed individuals such as chronic lymphocytic leukemia (CLL) patients are at risk for a suboptimal response to 2 vaccine doses (Herishanu Y, Blood, 2021). The French National Authority for Health recommends the use of a third dose in immunosuppressed patients. However, seroconversion rate after the triple-dose vaccine is not yet known. The objective of our study was to evaluate SARS-CoV-2 antibody responses after the first, second and third doses of the BNT162b2 and mRNA-1273 vaccines. Data were collected from 17 French Innovative Leukemia Organization (FILO) investigating centers and the French CLL patients' association (SILLC). SARS-CoV-2 IgG anti-Spike levels were measured at 4-6 weeks after each vaccine dose. A total of 530 patients and 14 controls were included in the study. Vaccine response was evaluated post-dose 1 for 158 CLL patients, post-dose 2, for 506 patients and post-dose 3 for 66 patients. Peripheral blood lymphocyte subsets were studied post-dose 2 by flow cytometry in 80 CLL patients and 14 controls. The median age of the patients was 71 years (range 37-93), 218 (40%) were treatment-naïve (TN), 136 (26%) had a prior CLL treatment and 176 (34%) were on therapy. Post-dose 1, the global response rate was 27% (43/158). TN patients had a response rate of 34% (23/67), similar to those who had a prior CLL treatment (33%,12/36), and higher compared to on-therapy patients (15%, 8/55, P=0.02). Post-dose 2, the global response rate was 52% (265/506). TN patients had the highest response rate of 72% (151/210) compared to previously treated patients, mostly by immunochemotherapy (60%, 78/130, P=0.02) and on-therapy patients (22%, 36/166, P65 years (OR 0.55, 95% CI 0.33-0.92, P=0.02), ongoing CLL treatment (OR 0.13, 95% CI 0.07-0.23, P Flow cytometry results suggest a differential balance of the T CD4+ cell subpopulations in Binet stage A and in patients on targeted therapy compared to healthy controls. Post-dose 2 seronegative patients were proposed a third dose and to date, 66 have been tested for the antibody response 4-6 weeks post-dose 3. The post-dose 3 response rate was 42% (28/66). TN patients and previously treated patients had a significantly higher response rate (57%, 16/28) compared to on-therapy patients (32%, 12/38, P=0.03). We further analyzed patients tested post-dose 2 with the Abbott Architect SARS-CoV-2 IgG anti-Spike assay (n=24). Those who achieved seroconversion after the third dose (n=10) had significantly higher titers post-dose 2 (median 12, IQR 3.0-40.8) compared to those who remained seronegative (n=14) (median 2.2, IQR 0.5-5.1, p An additional cohort of 40 CLL patients who presented a SARS-CoV-2 infection prior to vaccination participated to the study and was analyzed independently. All patients achieved seroconversion after infection and a single dose of vaccine, even though 30% (n=12) had an ongoing CLL treatment. In conclusion, double-dose mRNA vaccination generated a humoral response in 52% of our CLL cohort and a third dose induced seroconversion in 42% of the patients who remained seronegative after the second dose. The major independent predictor of negative antibody response was ongoing treatment with BTKi. The strongest boost to immune response against the virus seems to be SARS-CoV-2 infection, as a substantial increase in anti-Spike antibodies was observed in all CLL patients with prior infection, after a single dose vaccination. Figure 1 Figure 1. Disclosures Letestu: Janssen: Research Funding, Speakers Bureau; Roche: Speakers Bureau; AbbVie: Research Funding, Speakers Bureau. Dartigeas: Astra-Zeneca: Membership on an entity's Board of Directors or advisory committees, Other: travel grants/Congress; Abbvie: Membership on an entity's Board of Directors or advisory committees, Other: travel grants/Congress; Janssen: Membership on an entity's Board of Directors or advisory committees, Other: travel grants/Congress. Laribi: Astellas Phama, Inc.: Other: Personal Fees; BeiGene: Other: Personal Fees; AstraZeneca: Other: Personal Fees; IQONE: Other: Personal Fees; AbbVie: Other: Personal Fees, Research Funding; Takeda: Other: Personal Fees, Research Funding; Novartis: Other: Personal Fees, Research Funding; Le Mans Hospital: Research Funding; Jansen: Research Funding. Cymbalista: Lilly-LOXO: Honoraria, Membership on an entity's Board of Directors or advisory committees; Janssen: Honoraria, Membership on an entity's Board of Directors or advisory committees; ASTRA ZENECA: Honoraria, Membership on an entity's Board of Directors or advisory committees; Abbvie: 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.

With the emergence of targeted therapies, defining the best strategy for the treatment of previously untreated CLL patients remains challenging. The aim of this phase 2 study was to compare the efficacy of an association with ibrutinib and venetoclax (IV) to the standard FCR regimen in fit patients with intermediate risk CLL defined by either unmutated IGHV status, 11q deletion or complex karyotype in the absence of TP53 abnormality. Patients were randomized 1:1 between two treatment arms, ie FCR 6 cycles or IV. After a lead-in phase of ibrutinib as a single agent from month (M)1 to M3, the total duration of treatment with IV was based on the response achieved at M9; if bone marrow (BM) MRD was < 0.01% using flow cytometry, the treatment was continued for 6 additional months until M15 and then stopped; if BM MRD at M9 was ≥ 0.01%, the treatment with IV was continued for 18 additional months until M27. The primary endpoint was the percentage of patients with BM MRD < 0.01% at M27 in both arms. We present here the preliminary results on the first evaluation done at M9 including CT-scan, BM biopsy and MRD assessment in PB and BM after the inclusion of all the 120 patients as initially planned. One hundred and twenty patients were enrolled from September 2019 to February 2021. The median age was 59 [34-72] and 61 [34-74] years in the FCR and IV arms, respectively. The characteristics of the patients were well balanced between the 2 arms in terms of gender (male 72% FCR, 74% IV), PS ECOG 0-1 (59% FCR, 68% IV) and Binet stage (A, B and C 15%, 64%, 21% for FCR ; 8.5%, 59% and 32% for IV). No major difference in terms of cytogenetic features was noted, all patients but one had unmutated IGHV. At the time of data cut-off for this interim analysis, the median follow-up for the all cohort was 11 [2.9 - 19.8] months. The frequency of all grades adverse events (AE) observed so far was 53% (grade 3-4, 24%) in the FCR arm and 47% (grade 3-4, 17%) in the IV arm. The rate of infusion-related reactions (IRR) in the FCR arm was 35% on cycle 1-day 1 (14% grade 3-4) ; for the IV arm, 6% of patients experienced tumor lysis syndrome (TLS) (grade 4 for 4 patients). ibrutinib doses were reduced for 7 patients (4 permanently stopped and 3 resumed at a lower dose because of toxicities (digestive, hepatic or haematological)). Venetoclax was permanently discontinued before M9 in 4 patients (digestive toxicities and grade 4 neutropenia). Forty serious adverse events were reported of which 15 in the IV arm (1 sudden death, 1 ischemic stroke, 2 atrial fibrillations, 2 clinical TLS, 1 hepatitis, 1 neutropenia, 4 COVID pneumonitis and one osteoporotic fracture) and 25 in the FCR arm (2 neutropenias, 1 anemia, 1 thrombocytopenia, 1 autoimmune haemolytic anemia, 3 IRR, 4 TLS, 2 COVID pneumonitis, 4 fever episodes of undetermined origin, 1 community-acquired pneumonia, 1 gastrointestinal toxicity, 1 confusion, 2 chest pains, 1 acute myeloid leukemia, 1 myelodysplasic syndrome). The patients with COVID pneumonitis had a favorable evolution with the need for intensive care and convalescent plasma for 3 of them. The first 60 patients included in the study have reached M9 and among them, 6 prematurely discontinued the study, 3 in each arm (active hemolysis, ischemic stroke and sudden death in the IV arm; 2 grade 4 hematologic toxicities and 1 early progression in the FCR arm). In the evaluated patients (n=54), 71% of patients in the FCR arm and 48% of patients in the IV arm achieved bone BM MRD < 0.01%. The complete (CR, CRi) and partial response rates were 54% and 46% in the FCR arm and 76% and 24% in the IV arm respectively. In conclusion, the preliminary results show a lower BM MRD rate in the IV arm compared to the FCR arm at M9, with a toxicity that remains significant and relatively similar between the two arms. However, BM MRD rate should improve after longer exposure to the IV combination and the analysis of the primary endpoint at M27 will be decisive in determining the best therapeutic strategy. Disclosures Quinquenel: Abbvie: Honoraria; Janssen: Honoraria; AstraZeneca: Honoraria. Laribi: Le Mans Hospital: Research Funding; Novartis: Other: Personal Fees, Research Funding; Takeda: Other: Personal Fees, Research Funding; BeiGene: Other: Personal Fees; IQONE: Other: Personal Fees; AbbVie: Other: Personal Fees, Research Funding; Astellas Phama, Inc.: Other: Personal Fees; AstraZeneca: Other: Personal Fees; Jansen: Research Funding. Cymbalista: Lilly-LOXO: Honoraria, Membership on an entity's Board of Directors or advisory committees; Janssen: Honoraria, Membership on an entity's Board of Directors or advisory committees; ASTRA ZENECA: Honoraria, Membership on an entity's Board of Directors or advisory committees; Abbvie: 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. Leblond: AstraZeneca: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Lilly: Consultancy; AbbVie: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Travel Support; Roche: Honoraria; Amgen: Honoraria; Beigene: Honoraria, Membership on an entity's Board of Directors or advisory committees; Janssen: Honoraria, Membership on an entity's Board of Directors or advisory committees. Dartigeas: Astra-Zeneca: Membership on an entity's Board of Directors or advisory committees, Other: travel grants/Congress; Abbvie: Membership on an entity's Board of Directors or advisory committees, Other: travel grants/Congress; Janssen: Membership on an entity's Board of Directors or advisory committees, Other: travel grants/Congress. Ferrant: Janssen: Other: Travel, Accommodations, Expenses; AbbVie: Honoraria, Other: Travel, Accommodations, Expenses; AstraZeneca: Honoraria. de Guibert: Janssen: Consultancy, Honoraria; AbbVie: Consultancy, Honoraria; Gilead: Consultancy, Honoraria. Feugier: Astrazeneca: Consultancy, Honoraria; Gilead: Consultancy, Honoraria; Abbvie: Consultancy, Honoraria; Amgen: Honoraria; Janssen: Consultancy, Honoraria. Cartron: Roche, Celgene-BMS: Consultancy; Danofi, Gilead, Novartis, Jansen, Roche, Celgene-BMS, Abbvie, Takeda: Honoraria. Ysebaert: Abbvie, AstraZeneca, Janssen, Roche: Other: Advisory Board, Research Funding.

Background: Covalent Bruton's Tyrosine Kinase (BTK) inhibitors (BTKi) have transformed the management of chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL), but these treatments are not curative and the majority of patients will require additional treatment. Covalent BTKi share pharmacologic liabilities (e.g. low oral bioavailability, short half-life) that collectively may lead to suboptimal BTK target coverage, for example in rapidly proliferating tumors with high BTK protein turnover such as accelerating CLL/SLL, ultimately manifesting as acquired resistance in some patients. To address these limitations, pirtobrutinib, a highly selective, non-covalent BTKi that inhibits both wild type (WT) and C481-mutated BTK with equal low nM potency was developed. In a phase 1/2 BRUIN study, pirtobrutinib achieved pharmacokinetic exposures that exceeded its BTK IC96 at trough, was well tolerated, and demonstrated promising efficacy in CLL/SLL patients regardless of prior therapy, number of prior lines of therapy, or BTK C481 mutation status (Mato et al. Lancet 2021;397, 10277:892-901). Study Design and Methods: BRUIN CLL-313 is a randomized, open-label, global phase 3 study comparing pirtobrutinib monotherapy versus bendamustine plus rituximab (BR) in treatment naïve CLL/SLL patients with retained 17p. Approximately 250 patients will be randomized 1:1. Randomization will be stratified by IGHV mutation status (mutated vs unmutated), and Rai stage (low/intermediate vs high). Patients in the BR arm are eligible to crossover to pirtobrutinib monotherapy if they experience progressive disease per iwCLL 2018 and confirmed by an independent review committee (IRC). Eligible patients are adults with confirmed diagnosis of CLL/SLL and who require therapy per iwCLL 2018 criteria. Key exclusion criteria include CNS involvement by CLL/SLL, Richter transformation to DLBCL, prolymphocytic leukemia or Hodgkin lymphoma any time pre-enrollment, presence of 17p deletion, prior systemic therapy for CLL/SLL, and significant cardiovascular disease. The primary endpoint is progression-free survival (PFS) per iwCLL assessed by an IRC. Secondary endpoints include investigator-assessed PFS, overall survival (OS), overall response rate (ORR), duration of response (DoR), safety and tolerability, and patient reported outcomes. The global study is currently enrolling patients. Disclosures Jurczak: Abbvie, AstraZeneca, BeiGene, Celtrion, Celgene, Debbiopharm, Epizyme, Incyte, Janssen, Loxo Oncology, Merck, Mei Pharma, Morphosys, Novo Nordisk, Roche, Sandoz, Takeda, TG Therapeutics: Research Funding; Astra Zeneca, BeiGene, Janssen, Loxo Oncology, Sandoz, Roche,: Membership on an entity's Board of Directors or advisory committees. Dartigeas: Astra-Zeneca: Membership on an entity's Board of Directors or advisory committees, Other: travel grants/Congress; Abbvie: Membership on an entity's Board of Directors or advisory committees, Other: travel grants/Congress; Janssen: Membership on an entity's Board of Directors or advisory committees, Other: travel grants/Congress. Coscia: Gilead: Honoraria; AbbVie: Honoraria, Other; Janssen: Honoraria, Other, Research Funding; AstraZeneca: Honoraria. Wang: Eli Lilly and Company: Current Employment, Current equity holder in publicly-traded company. Bao: Loxo Oncology at Lilly: Current Employment; Genentech: Ended employment in the past 24 months. Leow: Loxo Oncology at Lilly: Current Employment, Current equity holder in publicly-traded company. Shahda: Loxo Oncology at Lilly: Current Employment, Current equity holder in publicly-traded company. Zinzani: Eusapharma: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Kyowa Kirin: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Merck: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Gilead: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Incyte: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; BMS: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Takeda: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Roche: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Servier: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Merck Sharp & Dohme: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; ADC Therapeutics: Consultancy, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Verastem: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Janssen Cilag: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Immune Design: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; TG Therapeutics: Honoraria, Speakers Bureau; Celtrion: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Sanofi: Consultancy; Beigene: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Celgene: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Abbvie: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Novartis: Consultancy, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Sandoz: Membership on an entity's Board of Directors or advisory committees; Portola: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Janssen: Consultancy, Honoraria, Speakers Bureau.

Background: Mantle cell lymphoma (MCL) is an aggressive type of non-Hodgkin lymphoma (NHL) and accounts for 6% of all NHL cases in Western countries (Thandra KC. Med Sci. 2021;9:5). First-line treatment options are not curative and most patients (pts) experience relapse (Wu H. Front Oncol. 2020:10:588314; Kumar A. Blood Cancer J. 2019;9:50). Targeted therapies, including Bruton's tyrosine kinase (BTK) inhibitors, are used as second- and later-lines; however, treatment intolerance and failure are common with poor survival outcomes (Epperla N. Hematol Oncol. 2017;35:528-35; Jain P. Br J Haematol. 2018;182:404-11). Thus, novel therapies are needed for pts with relapsed or refractory (R/R) MCL. Parsaclisib is a potent, highly selective, next-generation inhibitor of phosphatidylinositol 3-kinase (PI3K) δ. Here, we report results of the primary analysis of the cohort of BTK inhibitor-naive pts with R/R MCL treated with parsaclisib monotherapy in the open-label, phase 2 study CITADEL-205 (NCT03235544, EudraCT 2017-003148-19). Methods: Eligible pts were ≥18 years old, had pathologically confirmed MCL with documented cyclin D1 overexpression or t(11;14) translocation, and an Eastern Cooperative Oncology Group performance status (ECOG PS) ≤2. Pts must have received 1-3 prior systemic therapies and not had any prior treatment with a BTK and/or PI3K inhibitor. Pts were allocated to receive parsaclisib 20 mg once daily (QD) for 8 weeks followed by either 20 mg once weekly (weekly-dosing group [WG]) or 2.5 mg QD (daily-dosing group [DG]). Prophylaxis for Pneumocystis jirovecii pneumonia was required. The primary endpoint was objective response rate (ORR) as determined by an independent review committee (IRC); secondary endpoints included complete response rate (CRR), duration of response (DOR), overall survival (OS), progression-free survival (PFS), and safety and tolerability. All radiology-based endpoints were confirmed by an IRC. Results: At data cutoff for the primary analysis (Jan 15, 2021), 108 pts naive to prior BTK inhibitor had been treated (WG, n=31; DG, n=77). Median (range) age was 72.0 (43-90) years, 79.6% of pts were male, 92.6% had ECOG PS ≤1, and median (range) time since initial diagnosis was 3.6 (0.1-20.9) years. Among all pts, 63.9% had received 1 line and 25.9% had received 2 lines of prior systemic therapy (median [range], 1 [1-3]); 31.5% of pts had prior hematopoietic stem cell transplant, and 50.0% had relapsed and 43.5% were refractory to their most recent prior therapy. 78 pts (72.2%) had discontinued treatment; primary reasons were progressive disease in 49 (45.4%) and adverse events in 25 (23.1%) pts. Median (range) treatment duration and follow-up from first dose to data cutoff were 8.3 (0.1-30.0) and 22.9 (11.6-35.9) months for all pts, and 7.9 (1.7-27.4) and 18.2 (11.6-35.9) months for DG, respectively. The ORR (95% CI) was 68.5% (58.9-77.1) for all pts and 70.1% (58.6-80.0) for the DG (Table 1); CRR (95% CI) was 17.6% (10.9-26.1) for all pts and 15.6% (8.3-25.6) for the DG. Among all treated pts with complete or partial response, 89.2% of responses occurred at the first disease assessment. Median (95% CI) DOR was 13.7 (9.0-19.9) months for all pts and 12.1 (9.0-not estimable) months for the DG. Median (95% CI) PFS was 11.99 (8.3-16.9) months for all pts and 13.6 (10.0-16.9) months for the DG. Median OS was not reached. Among 108 treated pts, treatment-emergent adverse events (TEAEs) occurred in 90.7% (n=98) pts (grade ≥3 in 62.0% [n=67]). The most common TEAEs were diarrhea (34.3%), pyrexia (17.6%), and constipation (13.0%); most common grade ≥3 TEAEs were diarrhea (13.9%) and neutropenia (8.3%). TEAEs leading to dose interruption or dose reduction occurred in 47.2% and 8.3% of all pts, respectively. TEAEs led to treatment discontinuation in 25.0% of all pts; the most common were diarrhea (11.1%), colitis (4.6%), and hypokalemia (2.8%). Serious TEAEs occurred in 42.6% (n=46) of all pts; the most common were diarrhea (9.3%) and colitis (4.6%). Six pts (5.6%) overall experienced fatal TEAEs. Conclusion: Parsaclisib monotherapy demonstrated a rapid and durable response, had an acceptable safety profile, and was generally well tolerated in BTK inhibitor-naive pts with R/R MCL. These data suggest that parsaclisib could be a potential treatment option for pts with R/R MCL. Figure 1 Figure 1. Disclosures Mehta: Seattle Genetics; Incyte; TG Therapeutics: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Seattle Genetics; Incyte; TG Therapeutics: Consultancy; Affirmed; Kite/Gilead; Roche-Genetech; Celgene/BMS; Oncotartis; Innate Pharmaceuticals; Seattle Genetics; Incyte; Takeda; Fortyseven Inc/Gilead; TG Therapeutics; Merck; Juno Pharmaceuticals/Bristol Myers Squibb: Research Funding. Trněný: Janssen: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Travel, Accommodations, Expenses; MorphoSys: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Roche: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Travel, Accommodations, Expenses; Celgene: Consultancy; Takeda: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Travel, Accommodations, Expenses; 1st Faculty of Medicine, Charles University, General Hospital in Prague: Current Employment; Novartis: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Portola: Honoraria, Membership on an entity's Board of Directors or advisory committees; Amgen: Consultancy, Honoraria; AbbVie: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Travel, Accommodations, Expenses; Incyte: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; AstraZeneca: Honoraria; Gilead Sciences: Consultancy, Honoraria, Other: Travel, Accommodations, Expenses; Bristol-Myers Squibb: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Travel, Accommodations, Expenses. Walewski: Abbvie: 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, Research Funding; Amgen: Consultancy, Honoraria; Takeda: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Novartis: 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; BMS: Consultancy, Honoraria; Celgene: Consultancy, Honoraria; Janssen: Consultancy, Honoraria; Servier: Consultancy, Honoraria. Ribrag: Incyte: Membership on an entity's Board of Directors or advisory committees; Epizyme: Honoraria, Research Funding; Nanostring: Membership on an entity's Board of Directors or advisory committees; Roche: Membership on an entity's Board of Directors or advisory committees; GSK: Research Funding; Roche: Membership on an entity's Board of Directors or advisory committees; Argen-X: Research Funding; Bristol Myers Squibb: Membership on an entity's Board of Directors or advisory committees; Servier: Consultancy, Membership on an entity's Board of Directors or advisory committees; AstraZeneca: Membership on an entity's Board of Directors or advisory committees; Gilead: Membership on an entity's Board of Directors or advisory committees; PharmaMar: Honoraria, Membership on an entity's Board of Directors or advisory committees; MSD Pharmaceuticals: Membership on an entity's Board of Directors or advisory committees; Infinity Pharmaceuticals: Membership on an entity's Board of Directors or advisory committees; Astex Pharmaceuticals: Research Funding. Dartigeas: Astra-Zeneca: Membership on an entity's Board of Directors or advisory committees, Other: travel grants/Congress; Abbvie: Membership on an entity's Board of Directors or advisory committees, Other: travel grants/Congress; Janssen: Membership on an entity's Board of Directors or advisory committees, Other: travel grants/Congress. Pane: AbbVie; Amgen; Novartis: Other: Travel, accommodation, expenses; Novartis Pharma SAS;: Research Funding; AbbVie; Amgen; Novartis, GSK , Incyte: Consultancy; AbbVie; Amgen; Novartis, GSK, Incyte: Speakers Bureau; Daiichi Sankyo: Consultancy, Membership on an entity's Board of Directors or advisory committees, Other: Travel, Accommodations, ; Janssen: Other: Travel, Accommodations, ; Jazz Pharmaceuticals: Consultancy, Other: Travel, Accommodations, Speakers Bureau. Rodriguez: Bristol-Myers Squibb; Celgene; EUSA Pharma; Janssen; Roche; Takeda: Consultancy; Bristol-Myers Squibb; Celgene; Janssen; Roche; Takeda: Speakers Bureau. Taszner: Roche, Takeda: Consultancy, Other: Travel. Zilioli: Takeda: Other: travel expenses, accommodation; Roche, Italfarmaco: Consultancy, Honoraria; MSD, Janssen: Consultancy, Membership on an entity's Board of Directors or advisory committees, Other: Travel, Accommodations; Gentili, Takeda, Gilead, Servier: Consultancy, Speakers Bureau. Zheng: Incyte Corporation: Current Employment, Current equity holder in publicly-traded company. DeMarini: Incyte: Current Employment, Current equity holder in publicly-traded company. Jiang: Incyte: Current Employment, Current equity holder in publicly-traded company. Zinzani: Portola: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Servier: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Abbvie: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Celltrion: Consultancy, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Janssen-Cilag: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; BeiGene: Consultancy, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Takeda: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; ImmuneDesign: Consultancy, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Sanofi: Consultancy, Membership on an entity's Board of Directors or advisory committees; Verastem: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Bristol Myers Squibb: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Kyowa Kirin: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; TG Therapeutics Inc: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Roche: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Novartis: Consultancy, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Sandoz: Consultancy, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Incyte: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Celgene: Consultancy, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Merck Sharp & Dohme: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; ADC Therapeutics: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; EUSA Pharma: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Gilead: Consultancy, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau. OffLabel Disclosure: Investigational PI3Kdelta inhibitor (parsaclisib) for patients with MCL

Median age at diagnosis of chronic lymphocytic leukemia is 72 years. However, only few patients over 80 years of age are included in clinical trials, even in those devoted to unfit patients. In order to evaluate both efficiency and safety of venetoclax in this category of patients, we conducted a multicentric retrospective study and collected data from 77 CLL patients from 19 FILO centers who started venetoclax after 80 years of age. Median age at venetoclax initiation was 86 years old (81-97). 63% of patients had a history of heart disease, 62% had renal failure (moderate 59% and severe 3%) and 29% had a history of severe infections. Despite their comorbidities and a CIRS greater than 6 in 70% of cases, their autonomy was preserved with a median performans status of 1 (0-4). In this comorbid geriatric population, pretherapeutic geriatric assessment was only performed in a single patient. The median number of prior therapies was 2 (0-6) with an exposure to a BCR inhibitor in 56% of cases. 11q and 17p deletion were found in 39% and 30% of cases respectively, 39% of patients had a complex karyotype and 30% harbored a TP53 mutation. However, in this real life population, these prognostic factors were only performed in half of patients. IGHV mutational status was only available in 11 patients, and 83% of them had unmutated IGHV. At the time of venetoclax initiation, the tumor lysis syndrome (TLS) risk was moderate in 57% of cases and high in 8% of cases. Venetoclax was administered as a single agent (42%) or in association with rituximab (58%). In total, half of the patients were hospitalized at each dose ramp-up, and only 3 patients were treated on outpatient basis. 82% of the cohort was able to reach the daily dose of 400mg. Half of the patients were included in a phone call monitoring program with oncology nurses to pre-emptively manage side effects and foster therapy adherence. The safety study reported 14% of TLS, with 2 discontinuations of treatment within the first month: one of which led to dialysis and the other to death. As in the previously published studies, 25% of patients had infectious complications, and grade 3 haematological and digestive toxicities were reported in 42% and 22% of cases, respectively. The reduction of the daily dose of venetoclax was necessary for 33%. Permanent discontinuation of venetoclax occurred in 40% of subjects, including 29% of early withdrawal (within the first 3 months). Main reasons for discontinuation were intolerance (21%), CLL progression (21%), death (21%) and scheduled treatment discontinuation (10%). The overall response rate was 86%, consisting of 49% of complete response (unconfirmed by bone marrow biopsy) and 37% of partial response. With a median follow-up of 21months, estimated progression free survival and overall survival were 29 and 38 months respectively. Prior exposure to a BCR inhibitor had no impact on progression free survival. To conclude, venetoclax has a manageable safety profile in elderly patients with comorbidities and can induce prolonged responses. Finally, if additional follow-up by oncology nurses seems to be more and more implemented, the pre-therapeutic onco-geriatric evaluation remains underexploited in this population. Disclosures Ferrant: AstraZeneca: Honoraria; AbbVie: Honoraria, Other: Travel, Accommodations, Expenses; Janssen: Other: Travel, Accommodations, Expenses. Feugier: Janssen: Consultancy, Honoraria; Gilead: Consultancy, Honoraria; Abbvie: Consultancy, Honoraria; Amgen: Honoraria; Astrazeneca: Consultancy, Honoraria. Laribi: AstraZeneca: Other: Personal Fees; Le Mans Hospital: Research Funding; AbbVie: Other: Personal Fees, Research Funding; Jansen: Research Funding; Novartis: Other: Personal Fees, Research Funding; IQONE: Other: Personal Fees; Astellas Phama, Inc.: Other: Personal Fees; BeiGene: Other: Personal Fees; Takeda: Other: Personal Fees, Research Funding. Tchernonog: JANSSEN: Consultancy; ABBVIE: Consultancy; ASTRAZENECA: Consultancy. Dartigeas: Astra-Zeneca: Membership on an entity's Board of Directors or advisory committees, Other: travel grants/Congress; Abbvie: Membership on an entity's Board of Directors or advisory committees, Other: travel grants/Congress; Janssen: Membership on an entity's Board of Directors or advisory committees, Other: travel grants/Congress. Quinquenel: Abbvie: Honoraria; Janssen: Honoraria; AstraZeneca: Honoraria.

Background: Mantle cell lymphoma (MCL) accounts for approximately 5-7% of non-Hodgkin lymphomas (NHL). A number of therapies are used for second- and later-line treatment including Bruton's tyrosine kinase inhibitors (BTKi). However, treatment failure and intolerance are common and alternative therapies are needed. Parsaclisib is a potent, highly-selective, next-generation PI3Kδ inhibitor that demonstrated clinical activity in patients (pts) with relapsed or refractory (R/R) NHL. We report preliminary results for a cohort of BTK inhibitor-naïve pts with R/R MCL treated with parsaclisib monotherapy in the open-label, phase 2 study CITADEL-205 (NCT03235544). Methods: Pts must be ≥18 years of age with pathologically confirmed MCL, R/R to the most recent treatment, documented cyclin D1 overexpression or t(11;14) translocation, have Eastern Cooperative Oncology Group performance status (ECOG PS) ≤2, and received 1 to 3 prior systemic treatments. Prior treatment with BTKi and PI3Ki were prohibited. Pts were allocated to receive parsaclisib 20 mg once daily (QD) for 8 weeks followed by either 20 mg once weekly (weekly-dosing group [WG]) or 2.5 mg QD (daily-dosing group [DG]). Prophylaxis for Pneumocystis jirovecii pneumonia (PJP) was required. Objective response rate (ORR) was the primary endpoint; complete response rate (CRR), duration of response (DOR), progression-free survival (PFS), overall survival (OS), and safety and tolerability were secondary endpoints. All radiology-based endpoints were based on independent review. Results: From October 2017 to January 17, 2020 (data cut-off), 104 pts were treated (WG, n = 31; DG, n = 73). Enrollment was ongoing (target:100 pts). At cut-off, a total of 50 (48%) pts had discontinued treatment, including 31 (30%) pts for disease progression. The median exposure (range) was 4.0 months (0.1-19.1). The median age was 72 years and 80% of pts were men. The median time since initial diagnosis was 3.6 years. The majority of pts (92%) had ECOG PS ≤1, and 57% had high-risk MCL International Prognostic Index. The median number of previous systemic therapies was 1; 31% of pts had prior hematopoietic stem cell transplant, and 44% were refractory to their most recent systemic therapy. At the data cut-off, 92 pts were evaluable for efficacy including 31 in WG and 61 in DG (Table). The median follow-up duration (range) for this population was 11.8 months (1.9-24.0) overall and 9.1 (1.9-24.0) for DG. The ORR (95% confidence interval CI) and CRR were 66.3% (55.7-75.8) and 15.2%, respectively in all evaluable pts, and were 65.6% (52.3-77.3) and 11.5% for DG. The median time to response for pts with a complete or partial response was 7.9 weeks. The median DOR (95% CI) was 11.0 months (6.6-14.7) for all responders and 9.0 months (7.7-14.7) for DG. The median PFS (95% CI) was 11.1 (5.8-16.6) months overall, and 11.1 (5.6-16.6) months for DG. Among 104 safety-evaluable pts, most common treatment-emergent AEs (TEAEs) occurring in >10% of pts were diarrhea (25.0%), pyrexia (16.3%), constipation (11.5%), and neutropenia (10.6%). Most common grade ≥3 TEAEs reported in ≥5% of pts were neutropenia (8.7%) and diarrhea (7.7%). TEAEs leading to dose interruption or dose reduction occurred in 31.7% and 1.9% of pts, respectively. TEAEs leading to discontinuation occurred in 16.3% of pts including diarrhea (5.8%) and colitis (2.9%). Serious TEAEs reported in ≥2 pts included diarrhea (5.8%), colitis (2.9%), pyrexia (2.9%) and cytomegalovirus infection (1.9%). Four pts experienced fatal TEAEs. The fatal TEAEs in one pt (monocytic acute myeloid leukemia, leukocytosis, and acute kidney injury) were considered related to treatment. TEAEs of clinical interest included neutropenia (10.6%), rash (8.7%), colitis (4.8%), pneumonia (1.9%), PJP and pneumonitis (1% each). New or worsening grade ≥3 laboratory test values of clinical interest included decreased neutrophils (8.7%), platelets (7.7%), and hemoglobin (1.9%), and increases in alanine/aspartate aminotransferase (2.9%/1.9%). Conclusion: Parsaclisib demonstrated a high rate of rapid and durable response, and had an acceptable safely profile and was generally well tolerated. These preliminary results suggest that parsaclisib represents a potentially new drug class and treatment option for BTKi-naïve, R/R MCL. Updated study results will be presented. Disclosures Mehta: Takeda: Research Funding; Gelgene/BMS: Research Funding; Oncotartis: Research Funding; Merck: Research Funding; Incyte: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Kite/Gilead: Research Funding; Roche-Genentech: Research Funding; Affimed: Research Funding; TG Therapeutics: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Seattle Genetics: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Innate Pharmaceuticals: Research Funding; Juno Parmaceuticals/BMS: Research Funding; fortyseven Inc/Gilead: Research Funding. Trněný:AbbVie: Consultancy, Honoraria, Other: TRAVEL, ACCOMMODATIONS, EXPENSES (paid by any for-profit health care company); Incyte: Consultancy, Honoraria; Roche: Consultancy, Honoraria, Other: TRAVEL, ACCOMMODATIONS, EXPENSES (paid by any for-profit health care company), Research Funding; Celgene: Consultancy; MorphoSys: Consultancy, Honoraria; 1st Faculty of Medicine, Charles University, General Hospital in Prague: Current Employment; Amgen: Consultancy, Honoraria; Bristol Meyers Squibb: Consultancy, Honoraria, Other: TRAVEL, ACCOMODATIONS, EXPENSES (paid by any for-profit health care company); Takeda: Consultancy, Honoraria, Other: TRAVEL, ACCOMODATIONS, EXPENSES (paid by any for-profit health care company); Gilead Sciences: Consultancy, Honoraria, Other: TRAVEL, ACCOMMODATIONS, EXPENSES (paid by any for-profit health care company); Janssen: Consultancy, Honoraria, Other: TRAVEL, ACCOMMODATIONS, EXPENSES (paid by any for-profit health care company). Walewski:Servier: Consultancy, Honoraria; GSK: Research Funding; Janssen: Consultancy, Honoraria, Research Funding; Novartis: Consultancy, Honoraria, Research Funding; Roche: Consultancy, Honoraria, Other: Travel Support, Research Funding; Takeda: Consultancy, Honoraria, Research Funding; Abbvie: Consultancy, Honoraria; Amgen: Consultancy, Honoraria; BMS: Consultancy, Honoraria; Celgene: Consultancy, Honoraria; Gilead: Consultancy, Honoraria. Ribrag:Incyte: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Immune Design: Consultancy, Membership on an entity's Board of Directors or advisory committees; Roche/Genentech: Consultancy, Membership on an entity's Board of Directors or advisory committees; arGEN-X-BVBA: Research Funding; BAY1000394 studies on MCL: Patents & Royalties; Gilead: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; AstraZeneca: Honoraria, Membership on an entity's Board of Directors or advisory committees; F. Hoffmann-La Roche: Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Travel Expenses; Eisai: Honoraria; AZD: Honoraria, Other; Pharmamar: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Servier: Consultancy, Honoraria; Nanostring: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; BMS: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Travel Expenses; MSD: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Infinity: Consultancy, 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; Epizyme: Consultancy, Current equity holder in publicly-traded company, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Institut Gustave Roussy: Current Employment; argenX: Current equity holder in publicly-traded company, Research Funding. Dartigeas:Janssen: Honoraria; Roche: Honoraria; Gilead: Other: non-financial support. Pane:Bristol Myers Squibb: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Daiichi Sankyo: Consultancy, Other: Travel Expenses; Janssen: Other: Travel Expenses; Novartis pharma SAS: Consultancy, Other: Travel Expenses, Research Funding, Speakers Bureau; Jazz Pharmaceuticals: Consultancy, Other: travel expenses, Speakers Bureau; Celgene: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Amgen: Consultancy, Other: Travel Expenses, Speakers Bureau; AbbVie: Consultancy, Other: Travel Expenses, Speakers Bureau. Rodríguez:Celgene: Consultancy, Speakers Bureau; Janssen: Consultancy, Speakers Bureau; Roche: Consultancy, Speakers Bureau; Takeda: Consultancy, Speakers Bureau; Bristol-Myers Squibb: Consultancy, Speakers Bureau; EUSA Pharma: Consultancy. Zheng:Incyte: Current Employment, Current equity holder in publicly-traded company. DeMarini:Incyte Corporation: Current Employment, Current equity holder in publicly-traded company. Jiang:Incyte Corporation: Current Employment, Current equity holder in publicly-traded company. Zinzani:TG Therapeutics, Inc.: Honoraria, Speakers Bureau; Kyowa Kirin: Consultancy, Speakers Bureau; ADC Therapeutics: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Sanofi: Consultancy, Membership on an entity's Board of Directors or advisory committees; Immune Design: Consultancy, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Sandoz: Consultancy, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; MSD: Consultancy, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Immune Design: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; BMS: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; AbbVie: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Takeda: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Incyte: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Roche: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Janssen: Consultancy, Honoraria, Speakers Bureau; Servier: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Janssen-Cilag: Consultancy, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Kirin Kyowa: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Verastem: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Celgene: Consultancy, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; EUSA Pharma: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Portola: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Eusapharma: Consultancy, Speakers Bureau; Merck: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Celltrion: Consultancy, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Gilead: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau.

In patients with chronic lymphocytic leukaemia, achievement of a complete response with minimal residual disease of less than 0·01% (ie,1 chronic lymphocytic leukaemia cell per 10 000 leukocytes) in bone marrow has been associated with improved progression-free survival. We aimed to explore the activity of induction therapy for 9 months with obinutuzumab and ibrutinib, followed up with a minimal residual disease-driven therapeutic strategy for 6 additional months, in previously untreated patients.We did a single-arm, phase 2 trial in 27 university hospitals, general hospitals, and specialist cancer centres in France. Eligible patients were at least 18 years old and previously untreated, and had immunophenotypically confirmed B-cell chronic lymphocytic leukaemia; an Eastern Cooperative Oncology Group (ECOG) performance status score of less than 2; a Binet stage C according to IWCLL 2008 criteria or Binet stage A and B with active disease; no 17p deletion or absence of p53 mutation; and were considered medically fit. In the first part of the study (induction phase), all participants received eight intravenous infusions of obinutuzumab 1000 mg over six 4-weekly cycles and oral ibrutinib 420 mg once per day for 9 months. In part 2, after assessment on day 1 of month 9, patients with a complete response and bone marrow minimal residual disease of less than 0·01% received only oral ibrutinib 420 mg once per day for 6 additional months. Patients with a partial response, or with a complete response and bone marrow minimal residual disease of 0·01% or more, received 6 months of four 4-weekly cycles of intravenous fludarabine, cyclophosphamide, and obinutuzumab 1000 mg, alongside continuing ibrutinib 420 mg once per day. The primary endpoint was the proportion of patients achieving a complete response with bone marrow minimal residual disease less than 0·01% on day 1 of month 16 assessed by intention to treat (ITT). This trial is registered with ClinicalTrials.gov (number NCT02666898) and is still open for follow-up.Between Oct 27, 2015, and May 16, 2017, 135 patients were enrolled. After induction treatment (day 1 of month 9), 130 patients were evaluable, of which ten (8%) achieved a complete response with bone marrow minimal residual disease of less than 0·01% and were assigned to ibrutinib, and 120 (92%) were assigned to ibrutinib plus fludarabine, cyclophosphamide, and obinutuzumab. After minimal residual disease-guided treatment (day 1 of month 16), 84 (62%, 90% CI 55-69) of 135 patients (ITT population) achieved a complete response with bone marrow minimal residual disease of less than 0·01%. The most common haematological adverse event was thrombocytopenia (in 45 [34%] of 133 patients at grade 1-2 in months 1-9 and in 43 [33%] of 130 patients at grade 1-2 in months 9-15). The most common non-haematological adverse events were infusion-related reactions (in 83 [62%] patients at grade 1-2 in months 1-9) and gastrointestinal disorders (in 62 [48%] patients at grades 1 and 2 in months 9-15). 49 serious adverse events occurred, most frequently infections (ten), cardiac events (eight), and haematological events (eight). No treatment-related deaths occurred.Obinutuzumab and ibrutinib induction therapy followed by a minimal residual disease driven strategy is safe and active in patients with previously untreated chronic lymphocytic leukaemia. With longer follow-up, including assessing the evolution of minimal residual disease, if response is maintained, this strategy could be an option in the first-line setting in patients with chronic lymphocytic leukaemia, although randomised evidence is needed.Roche, Janssen.

The coexistence of dual hematological neoplasms is very rare. Sequential or synchronous neoplasms in hematology are an uncommon and complex clinical situation. The aim of the Hemo

Introduction: About 2 to 10% of patients (pts) diagnosed with Chronic Lymphocytic Leukemia (CLL) develop diffuse large B-cell lymphoma (DLBCL, so-called Richter transformation (RT)) over long-term follow-up. The outcomes of pts with RT are variable and poorly understood and there is no consensus on the best therapeutic approach. The aim of this study was to analyze the clinical characteristics, outcomes and factors predictive of survival in a large series of RT from the French Innovative Leukemia Organization (FILO). Methods: Biopsy-confirmed RT (limited to DLBCL and excluding Hodgkin lymphoma) diagnosed from 2001 to 2018 were identified from eight FILO centers. Clinical and biological characteristics of CLL and RT at diagnosis, including cytogenetics, clonal relation with the pre-existing CLL, Epstein-Barr virus (EBV) status, cell of origin (COO) analyzed by immunohistochemistry and RT score (Tsimberidou AM et al, J Clin Oncol, 2006) were analyzed as well as treatment and outcomes. Overall survivals (OS) were defined as time from CLL and RT diagnosis to death from any cause and analyzed using the Kaplan-Meier method. Statistical analyses were performed with SAS version 9.4. Results: A total of 70 CLL pts who developed RT were identified. The median age at CLL diagnosis was 62 years old (range 35-82), and 50 (71.4 %) were male. The median time to transformation was 5.5 years (range 0 to 22 years), with 12 simultaneous diagnosis of CLL and RT. Prior to RT, 20 (29%) pts had not been treated for CLL, 50 received one (n=21) or more (n= 29) line of treatment ; 6 pts had received a novel agent (ibrutinib, idelalisib or venetoclax). The median age at RT diagnosis was 68 years old (range 42-88). All biopsies were centrally reviewed; 38/58 pts (66%) had elevated LDH (>1.5N) ; 35/65 pts (54 %) had bulky disease (≥ 5 cm); 10/54 (18.5%) pts had del(17p) or TP53 mutation ; 9/42 pts (21%) had a complex karyotype (at least 3 abnormalities). The CLL and RT were clonally related in 27/27 (100%) tested pts. COO by Hans algorithm was non germinal center B cell-like (GCB) in 26/28 pts (93%). EBV was positive or detected in 5/40 (12.5%) pts. The median of Ki67 positivity was 70% (range 30% to 100%). The RT score (based at RT diagnosis on ECOG performance status 2-4, LDH >1.5 x normal, platelets5 cm and >1 prior therapy for CLL) was : low risk in 17 pts (31%), low-intermediate risk in 10 pts (19%), high-intermediate risk in 14 pts (25%) and high risk in 14 pts (25%). The most common first-line treatment of RT was immunochemotherapy (n=57, 87%) including R-CHOP-like regimen (n=48, 73%). Autologous or allogeneic transplantation was performed for 7 pts (11%). Response to first-line treatment was complete or partial response in 26 pts (40%), and stable disease or progression in 39 pts (60%). After a median follow-up of 8 years, 51/64 pts (80%) have died. The main causes of death were progressive DLBCL (n=36, 71%), infection (n=8, 16%) or progressive CLL (n=2, 4%). The median OS of the cohort from CLL and RT diagnosis (Figure 1) were 7.8 years and 9.5 months, respectively. In univariate analysis, patients with TP53 disruption at CLL stage, low platelets count, elevated LDH, elevated beta2-microglobulin, high ECOG score, high RT score, EBV positivity and absence of response to first-line RT treatment had worse OS. The ECOG score, platelets count and TP53 disruption remain significant in multivariate Cox-regression. Last, we compared the clinical and biological parameters of two Richter groups defined as: (i) short-term survivors (48 months, n = 18). Long survival was significantly associated with elevated platelets count, low LDH, low ECOG, low RT score and response to RT first-line treatment. Discussion: The clinical outcomes of RT patients is poor and novel treatment options are needed. However, a group of long-term survivors was identified, characterized by elevated platelets count, low LDH, low ECOG, low RT score and response to immunochemotherapy. Disclosures Leblond: Astra Zeneca: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Gilead: Honoraria, Speakers Bureau; Roche: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Janssen: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Abbvie: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Amgen: Honoraria, Speakers Bureau. Thieblemont:Roche: Honoraria, Research Funding; Gilead: Honoraria; Novartis: Honoraria; Kyte: Honoraria; Janssen: Honoraria; Celgene: Honoraria; Cellectis: Membership on an entity's Board of Directors or advisory committees. Cymbalista:Janssen: Honoraria; Gilead: Honoraria; AstraZeneca: Honoraria; Sunesis: Research Funding; Roche: Research Funding; Abbvie: Honoraria. Guièze:Abbvie: Honoraria; Janssen: Honoraria; Gilead: Honoraria; Roche: Honoraria. Broseus:Janssen: Honoraria; Gilead: Honoraria; Novartis: Research Funding. Feugier:gilead: Honoraria, Research Funding, Speakers Bureau; janssen: Honoraria, Research Funding, Speakers Bureau; abbvie: Honoraria, Research Funding, Speakers Bureau; roche: Honoraria, Research Funding, Speakers Bureau.

International audience; We present results of a prospective, multicenter, phase II study evaluating rituximab, bendamustine, bortezomib and dexamethasone as first-line treatment for patients with mantle cell lymphoma aged 65 years or older. A total of 74 patients were enrolled (median age, 73 years). Patients received a maximum of six cycles of treatment at 28-day intervals. The primary objective was to achieve an 18-month progression-free survival rate of 65% or higher. Secondary objectives were to evaluate toxicity and the prognostic impact of mantle cell lymphoma prognostic index, Ki67 expression, [18F]fluorodeoxyglucose-positron emission tomography and molecular minimal residual disease, in peripheral blood or bone marrow. With a median follow-up of 52 months, the 24-month progression-free survival rate was 70%, hence the primary objective was reached. After six cycles of treatment, 91% (54/59) of responding patients were analyzed for peripheral blood residual disease and 87% of these (47/54) were negative. Four-year overall survival rates of the patients who did not have or had detectable molecular residual disease in the blood at completion of treatment were 86.6% and 28.6%, respectively (P

International audience; Emergence of new agents has deeply modified treatment options and the role of chlorambucil (CLB) in B-cell malignancies. We conducted a systematic review of prospective, randomized, controlled trials (RCTs) investigating the benefits and harms of CLB used alone or in combination with other treatment in patients suffering from chronic lymphocytic leukemia (CLL), low-grade non-Hodgkin lymphoma (NHL) or Waldenström macroglobulinemia (WM). For CLL, review of the nine RCTs showed that the main advantage of CLB is its low toxicity in comparison with purine nucleoside analogs like fludarabine in either CLL or NHL. In CLL, the major disadvantage is the very low rate of complete response, except when combining an anti-CD20 antibody. For B-cell lymphoma and WM, six RCTs were summarized. Results according to the usual criteria are presented and the role of CLB, used mostly in combination with an anti-CD20 antibody, is discussed for each indication, in particular for unfit patients.

International audience