Abstract: Complex karyotypes have been associated with inferior outcomes in chronic lymphocytic leukemia (CLL) treated with chemoimmunotherapy (CIT), whereas their prognostic impact in the context of venetoclax-based treatments is still debated. In this prospective analysis on karyotype complexity in CLL, we evaluated the impact of complex (≥3 chromosomal aberrations [CAs], CKTs) and highly complex karyotypes (≥5 CAs; hCKTs) as well as specific aberrations in previously untreated patients without TP53 aberrations undergoing either CIT or time-limited venetoclax-based therapies in the phase 3 GAIA/CLL13 trial. Karyotype analyses were available for 895 of 926 patients (96.7%), of whom 153 (17%) had a CKT and 43 (5%) hCKT. In the CIT arm, CKT was associated with shorter progression-free survival (PFS) (hazard ratio [HR] 2.58; 95% confidence interval [95% CI], 1.54-4.32; P  & lt; .001) and overall survival (HR, 3.25; 95% CI, 1.03-10.26; P = .044). In the pooled venetoclax arms, a multivariable analysis identified hCKTs (HR, 1.96; 95% CI, 1.03-3.72; P = .041), but not CKTs, as independent adverse prognosticators for PFS. The presence of translocations (unbalanced and/or balanced) was also independently associated with shorter PFSs in the venetoclax arms. CIT led to the acquisition of additional CAs (mean CAs, 2.0-3.4; from baseline to CLL progression), whereas karyotype complexity remained stable after venetoclax-based treatments (2.0, both time points). This analysis establishes highly complex karyotypes and translocations as adverse prognostic factors in the context of venetoclax-based combination treatments. The findings of this study support the incorporation of karyotyping into the standard diagnostic workup of CLL, because it identifies patients at high risk of poor treatment outcomes and thereby improves prognostication. This trial was registered at www.clinicaltrials.gov as #NCT02950051.

Abstract: Activating mutations of the BRAF kinase (BRAF V600E) are found in virtually all cases of classical hairy-cell leukemia (HCL), suggesting disease-specific oncogene dependence. Case reports and early trial data demonstrate impressive activity of BRAF inhibitors, but optimal dosing and treatment duration remain unclear. Methods: We report on 21 patients with hairy cell leukemia across Europe (Heidelberg, Innsbruck, Nice, Munich, Cambridge, Erfurt, Freiburg, Luzern, Cologne, Leicester, London) treated with vemurafenib, a specific BRAF inhibitor outside of trials from 2011-2014. Centers provided clinical data and pathology specimen where available. Results: Presence of the BRAFV600E mutation was demonstrated in all patients. Median age of all patients included in this study was 64 (range 45-89) years. Patients received a median of 3 (range 0 to 12) prior treatment lines. Two patients were treated upfront (age, comorbidity). Median time between initial diagnosis and experimental treatment with vemurafenib was 8 (range 0-31) years. Vemurafenib was started at a dose of 240 mg bid in 18 patients and was continued at this dose in 14 patients. In four patients doses were escalated to 720 mg (n=1) and 960 mg (n=3), respectively. Three patients received 480 mg (n=2) bid or 960 mg (n=1) bid upfront. Median therapy duration was 90 (range 55-167) days, and 2 patients are still on therapy (day 85 and 275) at last follow up. All patient's blood counts improved meeting response criteria (Hb 〉 12g/dl, platelets 100.000/ µl, neutrophils 〉 1000µl), except for a 89-year-old patient who did not improve with his hemoglobin due to renal anemia. Median time to neutrophil recovery ( 〉 1000/ µl) was 39 (range 9-126) days, to platelet recovery ( 〉 100.000 µl) 28 (range: 10-105) days and time to improvement of anemia (Hb 〉 12 g/dl) 67 (range: 10-105) days, respectively. Seven patients achieved a CR and 13 a PR. Patients who received more than 240 mg bid (n=8) did not have significant more CRs than patients who received 240 mg (n=14) (Fishers test p=0.16). CR did not translate into better EFS (HR 1.2, p=0.7, Figure 1). Immune histology staining was performed to assess p-ERK signaling. Median observation time was 12 months (range: 3-31 months) and median event free survival (retreatment or death) was 17 months for all patients (Figure 1). Survival at 12 months was 87%. Three of 21 patients died; one patient due to HCL disease progression after termination of vemurafenib, one patient developed an AML M6 and one patient died at the age of 89 years due to pneumonia off treatment in remission. Seven patients (28%) including the 2 patients treated upfront were retreated at relapse after a median of 10 months (range: 4-16 months) after stopping vemurafenib. Six patients were reexposed to vemurafenib and one received cladribine. All patients responded again to vemurafenib and two patients continue to receive ongoing treatment at 240mg bid and 480mg bid respectively, 18 months and 8.5 months from restarting therapy. Conclusion: Targeting a BRAF V600E can provide disease control in HCL. CR was achieved in 30% of patients and can be achieved with 240 mg bid. Relatively short EFS suggests that treatment duration and dosing regimen should be optimized and combination treatments involving BRAF inhibitors should be explored in refractory HCL patients. Moreover, dosing schedules and treatment duration may need to be individualized in patients with HCL carefully taking into account individual pharmacodynamics and response. Figure 1: EFS (re-treatment or death) of HCL patients after vemurafenib treatment. Patients with CR (solid line) and patients with PR (dashed line) have similar EFS. Figure 1:. EFS (re-treatment or death) of HCL patients after vemurafenib treatment. Patients with CR (solid line) and patients with PR (dashed line) have similar EFS. Disclosures Herold: Roche Pharma AG/Germany: Honoraria, Research Funding. Dearden:Roche, GSK, Gilead, Janssen, Napp: Honoraria.

Abstract: Abstract 2860 Introduction: In the last decade, important progress has been achieved in the treatment of CLL through the use of purine analog-based chemoimmunotherapies. Several conditions remain a challenge, often with a poor outcome. Amongst these therapeutic problems are Richter's transformation (RT), refractoriness to F-based therapies (Fref), and the occurrence of AIC, which are sometimes induced by F. Fref and RT pts have a very poor prognosis with an estimated overall survival (OS) of only 10 and 8 months (mos), respectively. Therefore, therapeutic alternatives are urgently warranted. CHOP-R has improved the outcome of pts with aggressive non-Hodgkin's lymphoma. To test the efficacy and tolerability of the CHOP-R regimen in CLL patients with RT, Fref, or AIC, the GCLLSG initiated a prospective phase II trial. Material and Methods: 62 patients were included in the study. Due to protocol violations, 2 patients were excluded. Within the group of Fref pts, the medical review detected 11 patients who had received pre-treatment with F (Fpret), but were not refractory according to the updated guidelines (Hallek et al., Blood 2008). Thus, 26 pts were classified as Fref/pret, 19 pts as AIC and 15 pts as RT. All patients received CHOP every 3 weeks (cyclophosphamide 750mg/m2, adriamycin 50mg/m2 and vincristine 1, 4mg/m2 d1; prednisone 100mg/m2 d1–5). Rituximab was added starting with the 2nd cycle (375mg/m2 on each d0, and 21 days after the last CHOP-R). RT pts received up to 8, Fref/pret and AIC up to 6 courses of CHOP-R. In case of PD after 3 cycles, pts went off-study. The primary endpoints were remission rate, quality and duration of response. Results: 79%, 73%, and 40% of AIC, Fref/pret, and RT pts were male, respectively. The median age was 65 years (y) for Fref/pret-pts, 66y in the AIC and 69y in the RT group. Binet stages for Fref/pret pts were: A: 8%; B: 27% C: 65 %. All but 3 AIC pts were at Binet stage C. Initial RT stages according to Ann Arbor were: II: 13%, III: 13%, IV 73%. The median number of previous therapies were 3 for Fref/pret, 2 for AIC and 2 for RT. A total of 314 cycles were administered, with a median number of 3 cycles for AIC and Fref pts and a median number of 4 cycles for the RT group. Due to toxicity 73% of cycles in the Fref/pret group, 66% in the AIC and 87% in the RT group were dose-reduced. 69% of Fref/pret-pts and 58% of AIC-pts received full 6 cycles of therapy and only 40% of RT-pts completed 8 cycles of therapy. Treatment was stopped in 6 pts because of PD. Due to treatment related toxicity treatment was stopped in 16 pts (27%). Treatment related mortality was 3% (2 pts). Treatment toxicity was reported according to NCI common toxicity criteria (CTC) version 2.0. Adverse events grade 3 or 4 for anemia, neutropenia and thrombocytopenia were documented in 75%, 55% and 65% of patients, respectively. Infections were the most common non-hematologic toxicity and occurred in 67%; severe infections CTC grade 3 or 4 occurred in 28%. All 26 Fref/pret-pts were available for response evaluation. CHOP-R achieved 54% PR, 35% SD and 12% PD. The median progression-free survival (PFS) and median treatment-free survival (TFS) were 11 and 14 mos. OS was 27 mos with a significant difference concerning F-ref (n=15) and F-pret (n=11) pts (17 vs. 35m; p=0.05). We evaluated the response of all 15 RT-pts with 60% PR, 7% CR, 13% SD and 20% PD. The PFS was 15 mos, TFS was 17 mos and OS 27 mos. 17 AIC pts were available for response evaluation with 82% PR, 6% SD and 12% PD. The PFS and TFS were only 14 and 16 mos. The OS was 50 mos. The population had a high incidence of unfavourable genetic markers: deletion of chromosome 17p [del(17p)] was detected in 24%, del(11q) in 34% and unmutated IGHV in 70%. 85% had high levels of serum thymidine kinase (sTK 〉 10 U/l), and 49% had high levels of ß2-microglobulin (ß2M 〉 3.5 mg/l). Patients with del(17p) had an unfavourable response rate and achieved significant less a PR or CR (36% vs. 76%; p=0.03). Multivariate analyses showed that del(17p) and ECOG performance status had a negative prognostic impact on OS (p 〈 0.0001). Moreover the presence of a del(17p) predicted a short PFS (6 vs. 16.9 mos; p=0.001). Conclusion: CHOP-R achieves promising response rates in CLL patients with Fref and RT and very good response rates in patients with AIC. However, the progression-free survival and overall survival remain unsatisfactory. Therefore, CHOP-R might be used as induction therapy prior to allogeneic stem cell transplantation in physically fit patients. Disclosures: Eichhorst: Hoffmann La Roche: Honoraria, Research Funding, Travel Grants; Mundipharma: Research Funding, Travel Grants; Gilead: Consultancy. Dreyling:Roche: Research Funding, Scientific advisory board, Speakers Bureau. Bergmann:Celgene: Honoraria. Stilgenbauer:Hoffmann La Roche: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Travel Grants. Fink:Hoffmann La Roche: travel grants. Fischer:Hoffmann La Roche:. Wendtner:Hofmann-La Roche: Consultancy, Honoraria, Research Funding. Hallek:Roche: Consultancy, Honoraria, Research Funding; Mundipharma: Research Funding; Celgene: Honoraria.

Abstract: Introduction Chronic lymphocytic leukemia (CLL) is a disease of the elderly patient with a median age of 72 years at diagnosis. In addition to a generally increased obesity prevalence, higher age is also associated with increased body fat contents, and currently 22.5% of men and 31.8% of women above 65 years in Germany qualify as obese (body mass index [BMI] ≥30 kg/m²). While high BMI values are regarded as a risk factor for certain cancers, the impact of obesity on treatment outcomes is controversial and differs between genders. In aggressive B-cell lymphoma the prognosis of obese elderly women was worse following R-CHOP chemoimmunotherapy (CIT). With this meta-analysis the question whether obesity has an impact in CLL was addressed. Methods We analyzed pooled data from three prospective phase III trials (CLL4, CLL8, CLL10) of the German CLL study group (GCLLSG). With the aim to assess the effect of rituximab, patients treated with fludarabine monotherapy (F) or bendamustine and rituximab (BR) were excluded from this analysis. Underweighted patients (BMI 〈 18.5 kg/m², n=10) were excluded as well. Finally, the total analysis cohort comprised 1237 previously untreated patients receiving fludarabine and cyclophosphamide (FC) or FC plus rituximab (FCR). We analyzed progression-free survival (PFS) and overall survival (OS) according to baseline BMI (normal weight (NW) 18.5-24.9 kg/m²; overweight (OW) 25-29.9 kg/m²; obese (OB) ≥ 30 kg/m²), gender and treatment regimen. Kaplan-Meier curves were plotted and compared by non-stratified log-rank test. Hazard ratios (HR) and 95% confidence intervals (CI) were calculated using Cox regression modelling. Results In this combined cohort 560 (45.3%) patients received FC and 677 (54.7%) received FCR. 319 (25.8%) patients were female, 918 (74.2%) were male, median age was 60 years (range 30-81). The cohort comprised 497 (40.2%) NW patients, 521 (42.1%) OW patients and 219 (17.7%) OB patients. Median BMI was 25.1 kg/m² (range 18.6-45.0) in the female and 26.0 kg/m² (range 18.7-45.2) in the male study population. Clinical characteristics, in particular CLL-IPI risk groups and other prognostic factors, were equally distributed between BMI subgroups. Median observation time was 68.4 (range 0.4-151.3) months. OB patients received lower CIT doses compared to NW patients with regard to planned doses based on body surface area (Table 1). Medians of given dose intensities were for fludarabine: NW 95.1% (range 10.8-124.7) vs. OB 84.0% (range 9.2-121.0), for cyclophosphamide: NW 93.5% (range 11.1-105.7) vs. OB 84.0% (range 9.2-102.3), and for rituximab: NW 98.2% (range 0.1-108.7) vs. OB 88.9% (range 26.8-101.3). This difference was observed in male and female patients. We found significantly increased creatinine clearance rates in OB patients of both genders calculated by three different methods including the Salazar/Corcoran method that adjusts for obesity. PFS and OS according to the three BMI groups were not different in the entire cohort comprising both genders or males only. However, obese females had significantly worse outcomes following FCR treatment compared to NW females: median PFS was 44.6 in OB vs. 73.0 months in NW females (HR 1.743 [1.022-2.973]; p=0.041) and the median OS was 83.7 months compared to not reached in the female NW group (HR 3.013 [1.345-6.752] ; p=0.007) (Figure 1). These survival differences could not be detected in FC treated females (Figure 2). Conclusions Our data suggest that obesity is associated with significantly shorter PFS and OS in female CLL patients undergoing FCR chemoimmunotherapy but not conventional FC chemotherapy without rituximab. Therefore we assume that lower relative chemotherapy dose exposition that OB females received was not the major contributing factor to this survival difference. In contrast, we assume lower rituximab exposure in OB females treated with FCR due to obesity-associated increased clearance rates as described before. The significantly increased creatinine clearance rates in OB female patients might have additionally contributed to this effect, however the detailed mechanisms remain to be characterized. Our results are in line with recently published data on obesity as a survival risk factor in female patients with aggressive B-cell lymphoma undergoing R-CHOP CIT. Taken together, this warrants closer metabolic and anthropometric status evaluation in future immunotherapeutic studies. Disclosures Hopfinger: Roche: Consultancy, Honoraria; Takeda: Consultancy, Honoraria; GlaxoSmithKline: Honoraria; Celgene: Honoraria; Novartis: Consultancy, Honoraria; Janssen: Honoraria; Gilead: Honoraria, Research Funding. Fink:Celgene: Consultancy, Research Funding; AbbVie: Consultancy, Other: travel geants; Roche: Other: travel grants; Mundipharma: Other: travel grants. Al-Sawaf:Roche: Honoraria; Gilead: Honoraria; Abbvie: Honoraria. Langerbeins:Sunesis: Consultancy; AbbVie: Research Funding; Janssen: Consultancy, Honoraria, Other: Travel support, Research Funding; Mundipharma: Consultancy, Other: Travel grants; Roche: Consultancy, Other: Travel grants, Research Funding. Cramer:Mundipharma: Other: Travel grants; Roche: Honoraria, Other: Travel grants, Research Funding; Acerta: Consultancy, Research Funding; Novartis: Consultancy, Research Funding; GlaxoSmithKline: Research Funding; Gilead: Other: Travel grants, Research Funding; Abbvie: Consultancy, Honoraria, Other: Travel grants, Research Funding; AstraZeneca: Consultancy; Janssen: Consultancy, Honoraria, Other: Travel grants, Research Funding. Von Tresckow:Celgene: Consultancy, Other: Travel grants; Roche: Consultancy, Honoraria, Other: Travel grants, Research Funding; Janssen-Cliag: Consultancy, Honoraria, Other: Travel grants, Research Funding; AbbVie: Consultancy, Honoraria. Kutsch:Janssen: Other: Travel support; AbbVie: Other: Travel support; Mundipharma: Other: Travel support; Gilead: Research Funding. Hoechstetter:Hexal: Other: Travel Grants; Abbvie: Other: Travel Grants; Gilead Sciences: Consultancy, Other: Travel Grants. Dreyling:Gilead: Consultancy, Honoraria; Mundipharma: Consultancy, Research Funding; Janssen: Consultancy, Honoraria, Research Funding; Celgene: Consultancy, Honoraria, Research Funding; Bayer: Consultancy, Honoraria; Roche: Consultancy, Honoraria, Research Funding; Acerta: Consultancy; Sandoz: Consultancy. Kneba:AbbVie: Consultancy, Honoraria; Roche: Consultancy, Honoraria. Stilgenbauer:Genetech: Consultancy, Honoraria, Other: travel support, Research Funding; Novartis: Consultancy, Honoraria, Other: travel support, Research Funding; Celgene: 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; Pharmacyclics: Consultancy, Honoraria, Other: travel support, Research Funding; Mundipharma: Consultancy, Honoraria, Other: travel support, Research Funding; Roche: Consultancy, Honoraria, Other: travel support, Research Funding; Gilead: Consultancy, Honoraria, Other: travel support, Research Funding; Janssen: Consultancy, Honoraria, Other: travel support, Research Funding. Döhner:AbbVie: Consultancy, Honoraria; Sunesis: Consultancy, Honoraria, Research Funding; AbbVie: Consultancy, Honoraria; Astellas: Consultancy, Honoraria; Seattle Genetics: Consultancy, Honoraria; Astex Pharmaceuticals: Consultancy, Honoraria; Novartis: Consultancy, Honoraria, Research Funding; Seattle Genetics: Consultancy, Honoraria; Astellas: Consultancy, Honoraria; Bristol Myers Squibb: Research Funding; Amgen: Consultancy, Honoraria; AROG Pharmaceuticals: Research Funding; Amgen: Consultancy, Honoraria; Jazz: Consultancy, Honoraria; Janssen: Consultancy, Honoraria; Janssen: Consultancy, Honoraria; AROG Pharmaceuticals: Research Funding; Agios: Consultancy, Honoraria; Agios: Consultancy, Honoraria; Novartis: Consultancy, Honoraria, Research Funding; Sunesis: Consultancy, Honoraria, Research Funding; Pfizer: Research Funding; Celgene: Consultancy, Honoraria, Research Funding; Jazz: Consultancy, Honoraria; Celator: Consultancy, Honoraria; Bristol Myers Squibb: Research Funding; Astex Pharmaceuticals: Consultancy, Honoraria; Celator: Consultancy, Honoraria; Celgene: Consultancy, Honoraria, Research Funding; Pfizer: Research Funding. Hensel:Roche: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Celgene: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Shire: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; AbbVie: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Gilead: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Janssen: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees. Jaeger:Amgen: Membership on an entity's Board of Directors or advisory committees; Gilead: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Bioverativ: Membership on an entity's Board of Directors or advisory committees; Takeda-Millenium: Membership on an entity's Board of Directors or advisory committees; MSD: Research Funding; Takeda-Millenium: Membership on an entity's Board of Directors or advisory committees; AOP Orphan: Membership on an entity's Board of Directors or advisory committees; Janssen: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Infinity: Membership on an entity's Board of Directors or advisory committees; GSK: Membership on an entity's Board of Directors or advisory committees; Mundipharma: Membership on an entity's Board of Directors or advisory committees; Celgene: 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, Research Funding; Novartis: Membership on an entity's Board of Directors or advisory committees, Research Funding; AbbVie: Consultancy, Honoraria. Wendtner:Gilead: Consultancy, Honoraria, Research Funding; Abbvie: Consultancy, Honoraria, Other: travel support, Research Funding; GlaxoSmithKline: Consultancy, Honoraria, Other: travel support, Research Funding; Gilead: Consultancy, Honoraria, Other: travel support, Research Funding; MorphoSys: Consultancy, Honoraria, Other: travel support, Research Funding; Roche: Consultancy, Honoraria, Other: travel support, Research Funding; Mundipharma: Consultancy, Honoraria, Research Funding; Janssen: Consultancy, Honoraria, Other: travel support, Research Funding; Genetech: Consultancy, Honoraria, Other: travel support, Research Funding; Pharmacyclics: Consultancy, Honoraria, Other: travel support, Research Funding. Goede:Janssen: Honoraria, Other: Travel grants; Abbvie: Consultancy; Gilead: Consultancy, Honoraria; Roche: Consultancy, Honoraria, Other: Travel grants. Fischer:Roche: Other: Travel support. Hallek:Janssen: Honoraria, Research Funding; Celgene: Honoraria, Research Funding; Abbvie: Honoraria, Research Funding; Roche: Honoraria, Research Funding; Gilead: Honoraria, Research Funding; Pharmacyclics: Honoraria, Research Funding; Mundipharma: Honoraria, Research Funding. Eichhorst:AbbVie, Celgene, Gilead, Janssen, Mundipharma, Novartis, Roche: Honoraria, Other: Travel support, Research Funding.

Abstract: INTRODUCTION Chronic lymphocytic leukemia (CLL) is frequently associated with an impaired humoral and cellular immunity. On a global scale chemoimmunotherapy (CIT) has remained one of the most frequently used treatment option. Thus, patients (pts) may experience further cytopenia, particularly treatment-related neutropenia, increasing the risk of infections. In order to better characterize incidence, characteristics and outcomes of infections during and after therapy, a pooled analysis of phase II and III German CLL Study Group trials was performed. METHODS Data of first line pts from 5 clinical trials (CLL7, pts treated with fludarabine, cyclophosphamide, rituximab [FCR]; CLL8, FC vs FCR; CLL10, FCR vs bendamustine-rituximab [BR] ; CLL11, chlorambucil [CLB] vs CLB-R vs CLB-Obinutuzumab [CLB-Ob] and CLL2M, BR) were analyzed. Clinical, laboratory, genetic and event-related data were pooled. Infections defined as severe (CTC grade 3-5) from initiation of therapy until 4 weeks after completion of study treatment were considered related. Due to varying reporting periods for infections of the respective trials later events of infections were not included. Kaplan-Meier curves for landmark overall survival (OS) from completion of study treatment plus 4 weeks were plotted and compared by non-stratified log-rank test. Hazard ratios (HR) and 95% confidence intervals (CI) were calculated using Cox proportional-hazard regression modelling. RESULTS Data from 2,291 pts receiving at least one dose of CIT were pooled. Median observation time was 71.7 months, ranging between 43.7 months (CLL2M) and 81.0 months (CLL10). Seven-hundred and twenty-seven pts received FCR, 396 pts FC, 395 pts BR, 116 pts CLB, 326 pts CLB-R and 331 pts CLB-Ob. Overall, 274 severe grad 3/4/5 infections were reported in 229 pts (10.0% of 2,291 pts). Of those 189 pts (82.5%) had max. grade 3 infections, 22 (9.6%) pts had grade 4 infections and 18 (7.9%) pts died due to infectious complications. Median time to severe infection from start of treatment was 1.8 months (IQR 0.9-3.6), with a median number of infectious episodes per patient of 1 (range 1-4). Thirty-one (13.5%) of 229 pts had bacterial infections, 35 (15.3%) viral infections, 5 (2.2%) fungal infections and 172 (75.1%) unspecified infections. Higher grade (i.e. ≥ CTC grade 3) leukopenia and/or neutropenia was reported in 121 (52.8%) pts with severe infections. Eighty-eight (12.1%) of FCR treated pts had severe infections, followed by BR 45 (11.4%), CLB 12 (10.3%), FC 35 (8.8%), CLB-Ob 25 (7.6%) and CLB-R 24 (7.4%). Median age was 64 years in the entire cohort; no differences between pts with and without infections were observed with regards to age, sex, ECOG or creatinine clearance. Molecular and cytogenetic characteristics (deletion 17p, deletion 11q, trisomy 12) and IGHV status were similarly distributed between both groups. Median neutrophil count at enrolment was 4.4x10-9/l in both groups, respectively. Prior to therapy, levels of immunoglobulin were comparable between pts with and without infections (median IgG 7.0 vs 7.5 g/L, IgM 0.3 g/L vs 0.3 g/L). Also, pts with at least one episode of ≥ CTC grade 3 leukopenia/neutropenia had comparable rates of severe infections to pts without higher grade leukopenia/neutropenia (147 [53.6%] vs 127 [46.4%] pts). No differences were observed between pts with or without infections regarding the response to first line treatment (183 pts [79.9%] with complete response or partial response to treatment vs 1715 pts [83.2%] ) as well as the rate of undetectable minimal residual disease levels (50 [21.8%] vs 477 [23.1%] ). Overall survival from 4 weeks after completion of study treatment was significantly shorter in pts with severe infections compared to pts without severe infections (median 73.7 months vs 97.3 months, HR 1.503, 95% CI 1.217-1.856, p & lt; 0.001). CONCLUSION This analysis confirms that prognosis of CLL pts who received first line treatment with (immuno)chemotherapy is influenced by severe infections. This risk does not correlate with the explored cyto- or molecular genetic risk factors, nor with response to treatment, pre-therapeutic levels of immunoglobulins or occurrence of higher grade neutropenia. Pts who experience severe infections have a significantly shorter overall survival compared to pts without severe infections. Due to their vulnerability, careful management of infectious complications in CLL pts is warranted. Figure 1 Disclosures Al-Sawaf: AbbVie: Consultancy, Honoraria, Other: personal fees, Research Funding; Janssen: Consultancy, Honoraria, Other: personal fees, Research Funding; AstraZeneca: Consultancy, Honoraria, Other: personal fees; BeiGene: Research Funding; Roche: Consultancy, Honoraria, Other: personal fees, Research Funding; Gilead: Consultancy, Honoraria, Other: personal fees. Fink:Janssen: Honoraria; Celgene: Research Funding; AbbVie: Other: travel grants. Cramer:F. Hoffmann-LaRoche: Honoraria, Other: travel support, Research Funding; AstraZeneca: Consultancy, Honoraria, Other: travel support, Research Funding; Acerta: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Janssen-Cilag: Consultancy, Honoraria, Other: travel support, Research Funding; Beigene: Research Funding; Novartis: Consultancy, Research Funding; Gilead: Other: travel support, Research Funding; AbbVie: Honoraria, Other: travel support. Herling:Roche: Other: Travel support, Research Funding. Von Tresckow:Janssen-Cilag: Honoraria, Other: travel grants, Research Funding; Celgene: Other: travel grants; F. Hoffmann-LaRoche: Honoraria, Other: travel grants, Research Funding; AbbVie: Honoraria. Böttcher:Novartis: Honoraria; AbbVie: Honoraria, Research Funding; Celgene: Research Funding; Janssen: Honoraria, Research Funding; Roche: Consultancy, Honoraria, Research Funding. Dreyling:Astra Zeneca: Consultancy; Abbvie: Research Funding; Roche: Consultancy, Research Funding, Speakers Bureau; Bayer: Consultancy, Speakers Bureau; Beigene: Consultancy; Gilead: Consultancy, Research Funding, Speakers Bureau; Janssen: Consultancy, Research Funding, Speakers Bureau; Novartis: Consultancy; Celgene: Consultancy, Research Funding, Speakers Bureau. Jaeger:F. Hoffmann-La Roche: Honoraria, Research Funding; Gilead: Honoraria, Research Funding; BMS/Celgene: Consultancy, Honoraria, Research Funding; Infinity: Honoraria; Takeda: Honoraria; Amgen: Honoraria; Karyopharm: Honoraria; CDR Life AG: Consultancy, Research Funding; Miltenyi: Consultancy, Honoraria; True North: Honoraria, Research Funding; AbbVie: Honoraria; Novartis: Consultancy, Honoraria, Research Funding. Gregor:Roche: Honoraria; Mundipharma: Honoraria; AbbVie: Honoraria; Amgen: Honoraria; Celgene: Honoraria; Janssen: Honoraria; Pfizer: Honoraria. Ritgen:Pfizer: Consultancy, Honoraria; BMS: Consultancy, Honoraria, Other: travel grants; F. Hoffman-La Roche: Consultancy, Honoraria, Other: travel grants, Research Funding; Gilead: Other: travel grants. Dürig:Janssen: Consultancy; AbbVie: Consultancy; Celgene: Consultancy. Tausch:AbbVie: Consultancy, Honoraria, Research Funding; Janssen-Cilag: Consultancy, Honoraria, Research Funding; Roche: Consultancy, Honoraria, Research Funding. Stilgenbauer:GlaxoSmithKline: Consultancy, Honoraria, Other: travel support, Research Funding; Janssen-Cilag: Consultancy, Honoraria, Other: travel support, Research Funding; Mundipharma: Consultancy, Honoraria, Other, Research Funding; Gilead: Consultancy, Honoraria, Other: travel support, Research Funding; Genzyme: Consultancy, Honoraria, Other: travel support, Research Funding; Novartis: Consultancy, Honoraria, Other, Research Funding; Pharmacyclics: Consultancy, Honoraria, Other, Research Funding; Genentech: 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; Amgen: Consultancy, Honoraria, Other: travel support, Research Funding; AbbVie: Consultancy, Honoraria, Other: travel support, Research Funding. Wendtner:Janssen-Cilag: Consultancy, Honoraria, Other: travel support, Research Funding; GlaxoSmithKline: Consultancy, Honoraria, Other: travel support, Research Funding; Gilead: Consultancy, Honoraria, Other: travel support, Research Funding; Genentech: Consultancy, Honoraria, Other: travel support, Research Funding; Hoffmann-LaRoche: Consultancy, Honoraria, Other: travel support, Research Funding; AbbVie: Consultancy, Honoraria, Other: travel support, Research Funding; Mundipharma: Consultancy, Honoraria, Other: travel support, Research Funding; Pharmacyclics: Consultancy, Honoraria, Other: travel support, Research Funding. Fischer:F. Hoffmann-La Roche: Honoraria, Other: travel grants; AbbVie: Honoraria. Goede:AbbVie: Membership on an entity's Board of Directors or advisory committees; F. Hoffmann-LaRoche: Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: travel grants; Janssen: Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: travel grants; Gilead: Honoraria, Membership on an entity's Board of Directors or advisory committees. Hallek:F. Hoffmann-LaRoche: Consultancy, Honoraria, Research Funding; AbbVie: Consultancy, Honoraria, Research Funding; Celgene: Consultancy, Honoraria, Research Funding; Janssen: Consultancy, Honoraria, Research Funding; Mundipharma: Consultancy, Honoraria, Research Funding; Gilead: Consultancy, Honoraria, Research Funding. Eichhorst:Oxford Biomedica: Consultancy, Honoraria, Other: travel support, Research Funding; AstraZeneca: Consultancy, Honoraria, Other: travel support, Research Funding; Gilead: Consultancy, Honoraria, Other: travel support, Research Funding; BeiGene: Consultancy, Honoraria, Other: travel support, Research Funding; ArQule: Consultancy, Honoraria, Other: travel support, Research Funding; Novartis: Consultancy, Honoraria, Other: travel support, Research Funding; Celgene: Consultancy, Honoraria, Other: travel support, Research Funding; Janssen-Cilag: Consultancy, Honoraria, Other: travel support, Research Funding; AbbVie: Consultancy, Honoraria, Other: travel support, Research Funding; F. Hoffmann-LaRoche: Consultancy, Honoraria, Other: travel support, Research Funding. Langerbeins:AbbVie: Honoraria, Other: travel grants, Research Funding; F. Hoffmann-LaRoche: Honoraria, Other: travel grants, Research Funding; Janssen-Cilag: Honoraria, Other: travel grants, Research Funding; Mundipharma: Honoraria, Other: travel grants, Research Funding.

Abstract: Introduction: In CLL, chemoimmunotherapies (CIT) and combinations with novel agents have proven to be highly effective with regard to eradication of minimal residual disease (MRD), while complete remissions (CR) are frequently not achieved due to residual lymphadenopathy. We have previously reported that minimal residual disease (MRD) negativity after CIT is a prognostic factor irrespective of the clinical response (Kovacs et al., JCO 2016). Because inferior outcome was observed in small subgroups of patients (pts) with residual lymphadenopathy, we analyzed the prognostic value of residual lymphadenopathy after CIT in comparison to MRD detection in a larger pt population. Methods: We included 361 pts receiving frontline CIT within 3 prospective clinical trials of the GCLLSG (CLL2M: 23 pts, CLL8: 113 pts, CLL10: 225 pts) with available CT/MRI scans to assess abdominal lymphadenopathy at the final restaging (FR; 2 months after the end of last treatment cycle). Pts with available data on all classical lymph node regions (N=217) were analyzed separately (Figure 1). Enlarged lymph nodes (LN+) were defined as 〉 1.5 cm in the longest diameter according to iwCLL 2008 guidelines regardless of the investigator-assessed response category. MRD levels in peripheral blood (PB) were assessed at FR. PFS and OS was analyzed from time point of radiological assessment. Kaplan-Meier curves were plotted and compared using the log-rank test. Hazard ratios (HR) and 95% confidence intervals (CI) were calculated using Cox regression modelling. Results: Of the 361 pts included in this analysis, 227 (62.9%) received fludarabine, cyclophosphamide and rituximab (FCR) and 134 (37.1%) pts received bendamustine and R (BR). Median age was 60 years (range, 34-79); median observation time was 55.8 months (mo) (3.2-85.5). 62 (17.2%) pts had residual abdominal LN+, 299 (82.8%) had no residual abdominal lymphadenopathy (LN-) at FR. Of 217 pts with documented CT/MRI of all LN regions at FR, 48 (22.1%) pts had residual LN+ in at least one LN region and 169 (77.9%) showed no residual LN in any of the regions. Baseline characteristics were equally distributed between pts with and without available radiological assessments, between pts with radiological assessments of all regions or only abdominal and between LN+ and LN- pts. MRD in PB was available for 231 (64.0%) pts in this analysis group; of these, 165 pts (71.4%) showed MRD negativity (MRD-) at FR. PFS and OS were analyzed for different LN size categories (≤1 cm; 〉 1 & ≤2 cm; 〉 2 & ≤3 cm; 〉 3 cm). Patient outcome decreased with larger residual abdominal LN size at FR with regard to PFS (median, 52.9 mo vs. 24.6 mo vs. 30.5 mo vs. 10.6 mo; p 〈 0.001) and OS (median, NR vs. 63.2 mo vs. 57.0 mo vs. 45.9 mo; p 〈 0.001). However, the iwCLL guideline cut-off at 1.5 cm was found to be appropriate. Using this 1.5 cm cut-off, PFS and OS were significantly worse in abdominal LN+ pts compared to abdominal LN- pts (median PFS: 20.4 mo vs. 52.5 mo; HR 2.806; CI=2.030-3.879; p 〈 0.001; median OS: 57 mo vs. not reached [NR]; HR 4.294; CI=2.600-7.091; p 〈 0.001). In pts with residual lymphadenopathy 〉 1.5 cm in any lymph node region, PFS and OS was significantly worse compared to LN- pts (median PFS: 27.3 mo vs. 60.4 mo; HR 2.409; CI=1.622-3.577; p 〈 0.001; median OS: 60.7 mo vs. NR; HR 4.445; CI=2.208-8.947; p 〈 0.001). In a multivariate analysis, abdominal LN size at FR was an independent prognostic factor for PFS and OS, while LN size in any lymph node region failed to show independent prognostic value (Table 1). In the MRD- group, PFS was significantly shorter in MRD-/LN+ pts compared to MRD-/LN- pts (abdominal LN: median, 34.7 mo vs. 75.6 mo; HR 2.150; CI=1.190-3.883; p=0.011; any LN: median, 34.7 mo vs. 75.6 mo; HR 2.343; CI=1.221-4.497; p=0.01). This observation was confirmed for OS (abdominal LN: 5-year survival, 52.9% vs. 88.8%; HR 3.153; CI=1.183-8.407; p=0.022; any LN: 5-year survival, 61.9% vs. 94.3%; HR 4.213; CI=1.179-15.016; p=0.027) (Figures 2 & 3). Conclusions: Residual abdominal lymphadenopathy at FR is an independent prognostic factor for PFS and OS regardless of MRD negativity. It remains to be determined whether these findings can be transferred to novel targeted agents such as kinase inhibitors, venetoclax, novel CD20 antibodies or combinations of these. Residual disease in the lymph node compartment may identify a pt population which might benfit from strategies using consolidation therapies. Disclosures Bahlo: Roche: Honoraria, Other: Travel Grants. Fink:Celgene: Consultancy, Research Funding; AbbVie: Consultancy, Other: travel geants; Roche: Other: travel grants; Mundipharma: Other: travel grants. Dreyling:Roche: Consultancy, Honoraria, Research Funding; Janssen: Consultancy, Honoraria, Research Funding; Mundipharma: Consultancy, Research Funding; Bayer: Consultancy, Honoraria; Celgene: Consultancy, Honoraria, Research Funding; Sandoz: Consultancy; Acerta: Consultancy; Gilead: Consultancy, Honoraria. Hess:CTI: Research Funding; Janssen: 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, Research Funding; Pfizer: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Celgene: Consultancy, Honoraria, Other: travel expenses, Research Funding; Abbvie: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees. Ritgen:Roche: Honoraria, Research Funding; abbvie: Research Funding. Kneba:AbbVie: Consultancy, Honoraria; Roche: Consultancy, Honoraria. Döhner:Bristol Myers Squibb: Research Funding; Jazz: Consultancy, Honoraria; Pfizer: Research Funding; Astellas: Consultancy, Honoraria; Celgene: Consultancy, Honoraria, Research Funding; Astex Pharmaceuticals: Consultancy, Honoraria; Amgen: Consultancy, Honoraria; Seattle Genetics: Consultancy, Honoraria; Astellas: Consultancy, Honoraria; Janssen: Consultancy, Honoraria; Celator: Consultancy, Honoraria; Pfizer: Research Funding; Amgen: Consultancy, Honoraria; AROG Pharmaceuticals: Research Funding; Agios: Consultancy, Honoraria; Sunesis: Consultancy, Honoraria, Research Funding; AROG Pharmaceuticals: Research Funding; AbbVie: Consultancy, Honoraria; Sunesis: Consultancy, Honoraria, Research Funding; AbbVie: Consultancy, Honoraria; Seattle Genetics: Consultancy, Honoraria; Novartis: Consultancy, Honoraria, Research Funding; Novartis: Consultancy, Honoraria, Research Funding; Agios: Consultancy, Honoraria; Celgene: Consultancy, Honoraria, Research Funding; Janssen: Consultancy, Honoraria; Jazz: Consultancy, Honoraria; Celator: Consultancy, Honoraria; Astex Pharmaceuticals: Consultancy, Honoraria; Bristol Myers Squibb: Research Funding. Stilgenbauer:AbbVie: Consultancy, Honoraria, Other: travel support, Research Funding; Roche: Consultancy, Honoraria, Other: travel support, Research Funding; Genetech: Consultancy, Honoraria, Other: travel support, Research Funding; Pharmacyclics: Consultancy, Honoraria, Other: travel support, Research Funding; Celgene: Consultancy, Honoraria, Other: travel support, Research Funding; Amgen: Consultancy, Honoraria, Other: travel support, Research Funding; GlaxoSmithKline: Consultancy, Honoraria, Other: travel support, Research Funding; Gilead: Consultancy, Honoraria, Other: travel support, Research Funding; Janssen: Consultancy, Honoraria, Other: travel support, Research Funding; Mundipharma: Consultancy, Honoraria, Other: travel support, Research Funding; Novartis: Consultancy, Honoraria, Other: travel support, Research Funding. Wendtner:Mundipharma: Consultancy, Honoraria, Research Funding; Pharmacyclics: Consultancy, Honoraria, Other: travel support, Research Funding; Gilead: Consultancy, Honoraria, Research Funding; GlaxoSmithKline: Consultancy, Honoraria, Other: travel support, Research Funding; Roche: Consultancy, Honoraria, Other: travel support, Research Funding; Abbvie: Consultancy, Honoraria, Other: travel support, Research Funding; Genetech: Consultancy, Honoraria, Other: travel support, Research Funding; Gilead: Consultancy, Honoraria, Other: travel support, Research Funding; Janssen: Consultancy, Honoraria, Other: travel support, Research Funding; MorphoSys: Consultancy, Honoraria, Other: travel support, Research Funding. Goede:Roche: Consultancy, Honoraria, Other: Travel grants; Janssen: Consultancy, Honoraria, Other: Travel grants; Gilead: Consultancy, Honoraria; AbbVie: Consultancy. Fischer:Roche: Other: Travel support. Böttcher:Genentech: Research Funding; Roche: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; AbbVie: Honoraria, Research Funding; Janssen: Honoraria; Celgene: Research Funding. Hallek:Janssen: Honoraria, Research Funding; Pharmacyclics: Honoraria, Research Funding; Abbvie: Honoraria, Research Funding; Roche: Honoraria, Research Funding; Celgene: Honoraria, Research Funding; Gilead: Honoraria, Research Funding; Mundipharma: Honoraria, Research Funding. Eichhorst:AbbVie, Celgene, Gilead, Janssen, Mundipharma, Novartis, Roche: Honoraria, Other: Travel support, Research Funding.

Abstract: Low doses of the BRAF inhibitor vemurafenib are highly effective in refractory hairy cell leukemia. Abrogation of BRAF V600E–induced signaling was consistently seen with 240 mg of vemurafenib twice daily.

Abstract: Introduction: For physically fit CLL pts with low comorbidity burden FCR is the standard frontline regimen in advanced CLL. The CLL10 study, an international phase III study evaluated the efficacy and tolerance of BR in comparison to FCR in frontline therapy of fit pts without del(17p). Methods and Patients: 158 sites in five countries (Germany, Austria, Switzerland, Denmark and Czech Republic) registered 688 CLL pts for central screening including immunophenotyping, FISH, comorbidity burden and renal function. 564 CLL pts with CIRS score ≤ 6, creatinine clearance 〉 70 ml/min and without del(17p) were enrolled between 10/2008 and 6/2011. Pts were randomly assigned 1:1 to receive 6 courses of FCR (N= 284; F 25mg/m2 i.v. d1–3, C 250 mg/m2 i.v. d1–3, R 375 mg/m2 i.v. d 0 at first cycle and 500 mg/m2 d1 all subsequent cycles; q 28 days) or BR (N=280; B 90mg/m² i.v. d1+2, R 375 mg/m2 i.v. d 0 at first cycle and 500 mg/m2 d1 all subsequent cycles; q 28 days). A general prophylactic use of antibiotics or growth factors was not recommended. Three patients (2 FCR, 1 BR) were excluded because of deferred treatment. The median CIRS score was 2. There was no difference in median age (61.6 years (yrs) for all pts), but a significantly higher proportion of pts ≥ 70 yrs was included in the BR arm (22% vs 14%, p=0.020). Binet A was present in 22%, Binet B in 38 % and Binet C in 40 %. Unmutated IGHV status was not balanced between both groups (68% in BR versus 55% in FCR arm; p=0.003). All other characteristics showed no differences. The mean number of administered FCR courses was 5.27 courses vs 5.41 BR course (p=0.017). Results: The median observation time for all patients was 35.9 months (mo). 547 pts (FCR 274 ; BR 273) were evaluable for response and all pts (282 FCR ; 279 BR) included for progression-free survival (PFS) and overall survival (OS) analysis. The overall response rate in both arms was 97.8% (p=1.0). The complete response (CR) rate according to IWCLL and confirmed by central bone marrow immunohistology was 40.7% with FCR compared to 31.5% with BR (p=0.026). Four-colour-flow MRD data from peripheral blood (sensitivity 10-4) were available from 355 pts (185 FCR; 170 BR) at final staging. In the FCR arm 74.1% and 62.9% in the BR arm respectively of all evaluated pts were MRD negative (p=0.024). Bone marrow samples, available in 129 FCR and 98 BR pts, were MRD negative in 58.1% and 31.6% of pts, respectively (p 〈 0.001). At 12 mo follow-up 58.2% of the pts in the FCR arm (46/79) were still MRD negative in comparison to 26.3% (20/76) after BR (p 〈 0.001). At 18 mo there were 53.8% (35/65) MRD negative cases versus 24.6% (16/65; p=0.006). Median PFS was 53.7 mo in the FCR arm and 43.2 mo in the BR arm (HR=1.589, 95% CI 1.25-2.079; p=0.001). While PFS was statistically not significant different between both arm in pts with mutated IGHV, pts with unmutated IGHV status had a median time to progression of 43.9 mo after FCR compared to 34.0 mo after BR (p=0.015). Physically fit subgroups (CIRS max 3, only one CIRS item, age 〈 65 yrs) benefited most from FCR therapy. The difference in PFS was statistically not significant between both arms in pts ≥ 65 years, CIRS 4-6 or 〉 1 CIRS item. Multivariate analysis identified treatment arm, age ≥ 65 yrs, male sex, high serum TK, del(11q), absence of del(13q) and IGHV status as independent prognostic factors for PFS. No difference in OS was observed (at 36 mo 90.6% for FCR vs 92.2% for BR; HR=1.030, 95% CI 0.618-1.717; p=0.910). For OS male gender, age ≥ 60 yrs, high serum TK and IGHV status were assessed as independent prognostic factors. Severe neutropenia was more often observed in the FCR arm (87.7% vs 67.8%, p 〈 0.001), but no significant difference in the incidence of anemia (14.2% vs. 12.0%; p=0.46) or thrombocytopenia (22.4% vs 16.5%; p=0.096) was documented. Severe infections occurred significantly more frequent (39.8% vs 25.4%, p=0.001) in the FCR arm during treatment phase until 6 months follow-up, especially in older pts (48.4% vs 26.8%; p=0.001). Treatment related mortality was 3.9% (FCR) and 2.1% (BR), respectively. Conclusion: The final analysis of the CLL10 study shows that FCR remains the standard therapy in very fit CLL patients, because it yields higher CR rates, more MRD negativity and longer PFS in comparison to BR. However, in elderly fit pts high toxicity rates and infection rates result into dose reductions leading to similar efficacy between both arms. Elderly fit pts or pts with previous infections might benefit from BR as alternative regimen. Disclosures Eichhorst: Roche: Membership on an entity's Board of Directors or advisory committees, Research Funding, Travel grant Other; Mundipharma: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding, Travel grant, Travel grant Other; GSK: Consultancy, Membership on an entity's Board of Directors or advisory committees; Janssen: Consultancy, Membership on an entity's Board of Directors or advisory committees; Gilead: Consultancy. Off Label Use: The Combination of Bendamustine and Rituximab is not approved for frontline chemoimmunotherapy of CLL. Fink:Celgene: Other. Maurer:Mundipharma: Travel grant Other. Kiehl:Roche: Membership on an entity's Board of Directors or advisory committees. Gregor:Roche: Consultancy, Honoraria; Mundipharma: Consultancy, Honoraria. Trneny:Roche: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Celgene: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Novartis: Research Funding; Janssen: Honoraria, Membership on an entity's Board of Directors or advisory committees. Fischer:Roche: Other. Döhner:Roche: Research Funding. Kneba:Roche: Consultancy, Research Funding; Mundipharma: Consultancy, Research Funding. Wendtner:Mundipharma: Consultancy, Honoraria, Research Funding; Hoffmann-La Roche: Consultancy, Honoraria, Research Funding. Klapper:Hoffmann-La Roche: Research Funding; Takeda/Millenium: Research Funding. Kreuzer:Roche: Consultancy, Research Funding; Mundipharma: Consultancy, Research Funding. Stilgenbauer:Roche: Consultancy, Honoraria, Research Funding; Mundipharma: Consultancy, Honoraria, Research Funding. Böttcher:Roche: Honoraria, Research Funding, Travel grant Other. Hallek:Roche: Consultancy, Research Funding; Mundipharma: Consultancy, Research Funding.

Abstract: Introduction Chemoimmunotherapy with FCR is the current standard for physically fit CLL patients (pts) without TP53 deletion/mutation. Due to better tolerability, BR should be considered in pts aged ≥ 65. Data from studies in CLL and other lymphomas suggest that women might have a better overall survival (OS) than male pts. The aim of this study was to evaluate the impact of gender on progression-free (PFS) and OS as well as on the rate of toxicities during and after therapy with FCR or BR. Methods Data from three clinical trials (phase II/III) of the GCLLSG including 1078 treatment naïve pts were analyzed. 683 pts received FCR (404 in CLL8 [FCR vs FC], 279 in CLL10 [FCR vs BR] ) and 395 received BR (278 in CLL10, 117 in CLL2M). Laboratory markers, genetic parameters as well as event-related data were pooled. Kaplan-Meier curves were plotted and compared by non-stratified log-rank test. Hazard ratios (HR) and 95% confidence intervals (CI) were calculated using Cox regression modelling. Independent prognostic factors for PFS and OS were identified by multivariate analyses using Cox regression modelling with stepwise selection procedures. Results Median age was 61 years (y) (30-81). 291 (27%) pts were female, 787 (73%) were male. Distribution of Binet stages was similar between women and men, as well as age, frequency of unfavorable genetic aberrations and mutations (17p deletion, 11q deletion, unmutated IGHV) or elevated serum parameters (thymidine kinase [TK], β2-microglobulin [B2M] ) except for trisomy 12 (18.7% in female vs 9.8% in male). Median observation time was 69.7 months in the CLL8 trial, 42.7 in CLL2M and 58.2 in CLL10 and 63.6 in the overall cohort. The CR rate with FCR treatment was 50% in female pts vs 41.9% in male pts and 29.5 vs 29.1% with BR treatment. At final restaging, 66.4% of female pts were MRD negative in peripheral blood (defined as & lt;10-4) vs 66.7% of male pts. 45.2% of female pts achieved MRD negativity in bone marrow vs 44.9% of male pts. 5-y-PFS was higher for women after FCR (52.5% vs 45.5%; HR=1.197 [0.949-1.510]; p =0.13) as well as after BR (44.8% vs 23.2%; HR=1.523 [1.124-2.063] ; p=0.007). While BR was significantly inferior to FCR in male pts (5-y-PFS 23.2% vs. 45.5%; HR=1.644 [1.359-1.988]; p & lt;0.001) the difference was not statistically significant in female pts (5-y-PFS 44.8% vs. 52.5%; HR=1.277 [95%CI 0.912-1.788]; p=0.154). Median OS for all groups was not yet reached. 5-y-OS after BR was 84.6% in women vs 74.7% in men (HR=1.705 [95%CI, 0.965-3.014]; p=0.07) and 80% vs 79.6% after FCR (HR=1.179 [0.831-1.673] ; p=0.36). OS according to gender did not differ significantly between men and women (5-y-OS 78.4 % vs 81.8%; HR=1.301 [0.966-1.752]; p=0.083), while PFS did differ significantly (5-y-PFS 38.6 % vs 50.1%; HR=1.283 [1.067-1.542] ; p=0.008). In multivariate analyses, independent adverse prognostic factors for PFS were BR treatment, male gender, TK ( & gt;10.0 U/l), unmutated IGHV, deletion 17p and deletion 11q. Factors associated with OS were age ( & gt;65y), B2M ( & gt;3.5 mg/l), TK ( & gt;10.0 U/l), unmutated IGHV and deletion 17p, but not gender. CTC grade 3 and 4, hematological adverse events (AE) were more frequent in female pts treated with FCR, particularly anemia (8.6% vs 5.6% in male), leukopenia (51.4% vs 41.0%) and neutropenia (57.3% vs 46.0%), but not thrombocytopenia (11.4% vs 11.8%). Frequency of dose reductions and median number of administered treatment cycles did not differ. Though frequency of hematological AEs was lower with BR compared to FCR, female pts experienced more severe anemia (10.4 % vs 8.7%), leukopenia (50% vs 36.3%), neutropenia (50.9% vs 39.8%), but not thrombocytopenia (15.1% vs 15.2%) compared to male pts. The rate of infections and infestations did not differ between genders during FCR (18.9 % vs 20.9%) as well as BR (12.3% vs 15.6%). After 5 years less female pts developed second primary malignancies (SPM) after FCR compared to male pts (6.7% vs 12.8%), while the rate of SPM after BR was similar between both genders (13.8% vs 13.1%). Conclusions Based on this pooled analysis of three prospective clinical trials in CLL, women had longer PFS than men after chemoimmunotherapy with either FCR or BR although the rate of hematological toxicities during therapy was higher. Understanding the causes of this observation can enable a more tailored, gender-specific approach in CLL treatment. Figure Overall survival (A) and progression free survival (B) according to treatment and gender. Figure. Overall survival (A) and progression free survival (B) according to treatment and gender. Disclosures Al-Sawaf: Gilead: Other: Travel grants. Bahlo:F. Hoffman-La Roche: Honoraria, Other: Travel grant. Fink:Mundipharma: Other: Travel grants; AbbVie: Other: Travel grants; Celgene: Research Funding; Roche: Honoraria, Other: Travel grants. Cramer:Hoffmann-LaRoche: Honoraria, Other: Travel grants, Research Funding; Gilead: Other: Travel grants, Research Funding; GlaxoSmithKline/Novartis: Research Funding; Janssen-Cilag: Honoraria, Other: Travel grants, Research Funding; Astellas: Other: Travel grants; Mundipharma: Other: Travel grants. Maurer:Mundipharma: Other: Travel grants. Bergmann:Mundipharma: Honoraria; Roche: Consultancy, Honoraria; Celgene: Honoraria; Glaxo-SmithKline: Honoraria; Gilead: Consultancy, Honoraria; Janssen: Honoraria. Dreyling:Roche: Consultancy, Honoraria, Research Funding, Speakers Bureau. Kneba:Roche: Consultancy, Honoraria, Other: Travel grants, Research Funding; Janssen-Cilag: Consultancy, Honoraria, Other: Travel grants; Gilead: Consultancy, Honoraria, Other: Travel grants, Research Funding; AbbVie: Consultancy, Honoraria, Other: Travel grants; Glaxo-SmithKline: Other: Travel grants; Amgen: Research Funding. Stilgenbauer:Boehringer-Ingelheim: Consultancy, Honoraria, Research Funding; Pharmacyclics LLC, an AbbVie Company: Consultancy, Honoraria, Other: Travel, Accommodations, Expenses, Research Funding, Speakers Bureau; Genentech: Consultancy, Honoraria, Research Funding; Amgen: Consultancy, Honoraria, Research Funding; Genzyme: Consultancy, Honoraria, Research Funding; Hoffman La-Roche: Consultancy, Honoraria, Research Funding; Novartis: Consultancy, Honoraria, Research Funding; AbbVie: Consultancy, Honoraria, Other: Travel, Accommodations, Expenses, Research Funding, Speakers Bureau; GlaxoSmithKline: Consultancy, Honoraria, Research Funding; Janssen: Consultancy, Honoraria, Other: Travel, Accommodations, Expenses, Research Funding, Speakers Bureau; Mundipharma: Consultancy, Honoraria, Research Funding; Celgene: Consultancy, Honoraria, Research Funding; Gilead: Consultancy, Honoraria, Research Funding; Sanofi: Consultancy, Honoraria, Research Funding. Kiehl:Roche: Consultancy, Other: Travel grants, Speakers Bureau. Jäger:Roche: Other: Personal fees, Research Funding. Wendtner:AbbVie: Consultancy, Honoraria, Research Funding; Genentech: Consultancy, Honoraria, Research Funding; Hoffmann-La Roche: Consultancy, Honoraria, Research Funding; Glaxo-SmithKline: Consultancy, Honoraria, Research Funding; Gilead: Consultancy, Honoraria, Research Funding; Novartis: Consultancy, Honoraria, Research Funding; Janssen-Cilag: Consultancy, Honoraria, Research Funding; Servier: Consultancy, Honoraria, Research Funding; Mundipharma: Consultancy, Honoraria, Research Funding. Fischer:Roche: Other: travel grants. Hallek:Gilead: Consultancy, Honoraria, Other: travel support, Research Funding, Speakers Bureau; F. Hoffmann-LaRoche: Consultancy, Honoraria, Other: travel support, Research Funding, Speakers Bureau; Janssen-Cilag: Consultancy, Honoraria, Other: travel support, Research Funding, Speakers Bureau; Mundipharma: Consultancy, Honoraria, Other: travel support, Research Funding, Speakers Bureau; AbbVie: Consultancy, Honoraria, Other: travel support, Research Funding, Speakers Bureau; Amgen: Consultancy, Honoraria, Other: travel support, Research Funding, Speakers Bureau; Celgene: Consultancy, Honoraria, Other: travel support, Research Funding, Speakers Bureau. Eichhorst:Janssen-Cilag: Consultancy, Honoraria, Other: travel support, Research Funding, Speakers Bureau; Roche: Consultancy, Research Funding, Speakers Bureau; Mundipharma: Consultancy, Research Funding, Speakers Bureau; GlaxoSmithKline: Consultancy, Honoraria, Other: travel support, Research Funding, Speakers Bureau; AbbVie: Consultancy; Celgene: Consultancy, Honoraria, Other: travel support, Research Funding; Gilead: Consultancy, Honoraria, Other: travel support, Research Funding, Speakers Bureau. Hopfinger:Mundipharma: Honoraria; Roche: Honoraria; Janssen: Honoraria; Gilead: Honoraria; Takeda: Honoraria.