Advanced Stage Chronic Lymphocytic Leukemia Research Articles

Omission of Anti-CD20 Antibody in Chronic Lymphocytic Leukemia during COVID-19 Pandemic: Twelve Month Course of Venetoclax Is a Safe and Effective Alternative Regimen

Introduction The current treatment for patients with advanced stages of Chronic Lymphocytic Leukemia (CLL) is the combination of the Rituximab - an Anti-CD 20 Antibody and Venetoclax - a BCL-2 inhibitor. However, during COVID-19 Pandemic, we were concerned that the immunodeficiency state induced by anti-CD20 antibody infusions would increase the risk of COVID-19 complications. Also, we were concerned about exposing cancer patients to long term anti-neoplastic treatments when there were so many unknowns about the new Sar-CoV-2 virus. Thus, in order to minimize these deleterious effects, and long exposure to cancer treatment, the CLL treatment was modified through omitting Rituximab, and using a 12-month course of Venetoclax as a single agent, with the goal of preventing COVID complications, but still achieving durable remissions. Methods Between February 2020 and September 2022, 13 patients with advanced stage CLL who met the treatment criteria, were treated with single agent Venetoclax with the mean age of 77 ranging from ages 56-99 and a Male to Female ratio of 10:3. Indications of treatment were as follows: bulky lymphadenopathy (8), markedly elevated lymphocyte count (3), and bone marrow failure (2). Among these 13 patients, there were 7 treatment naive patients and 6 had previously received between 1 to 3 treatments. These treatments included: Chlorambucil-Obinutuzumab, Ibrutinib, Fludarabine-Cyclophosphamide-Rituximab, and Bendamustine-Rituximab. Following are the FISH analysis results of these patients: 13Q14, 12+, TP53- , 11Q22-. Single agent venetoclax was administered to patients as a 5 week ramp up schedule per standard dosing guidelines, with the goal being to achieve 400 mg by week 5 of the treatment. The 400 mg dosage was continued for another 11 months and patients were monitored monthly for treatment response and toxicity. After the conclusion of 12 months of treatment, patients were followed up clinically at regular intervals to monitor durability of treatment response. Patients were informed that if there was progression noted during Venetoclax treatment, a new regimen that included Anti-CD20 Antibody will be started. Results Eleven out of 13 patients achieved full dosage escalation to 400 mg by week 5. Of the 2 patients that did not escalate the full dose, one patient - age 99- only achieved dosage up to 100 mg due to physician discretion, and the other patient achieved dosage up to 200 mg due to extreme fatigue. Common side effects amongst the patients were fatigue and mild cytopenia whilst the toxicity overall was manageable. One patient required treatment interruption for Autoimmune Hemolytic Anemia (AIHA) and only one patient contracted COVID-19. This patient recovered, however, quickly with no complications and treatment of Venetoclax was resumed at full dosage. Temporary increase in absolute lymphocyte count was noted in 8 patients. Mild persistent anemia was shown in 2 patients at the completion of treatment and mild thrombocytopenia was present in 7 patients. Neutropenia was not observed in any patients. Overall, treatment response was noted in 12 out of 13 patients with 11 complete remission (CR) and 1 partial remission (PR). Time to response was 3 months from the start of treatment for all responding patients. All patients who achieved CR and PR remain in remission during follow up with a median remission duration of 15 months. One patient had stable disease while on treatment but progressed immediately after discontinuation of Venetoclax. This patient then received the combination of Obinutuzumab-Acalabrutinib and achieved complete remission. Conclusion Thus, we can conclude that a 12-month course of Venetoclax administered without anti-CD 20 antibody, is an effective treatment regimen in advanced stage CLL. The avoidance of the anti-CD 20 antibody resulted in preservation of the immunity as noted in the one patient who contracted COVID-19 during treatment but recovered quickly from infection without any COVID-19 associated complication. We believe that although Rituximab with Venetoclax remains the standard of care in advanced stage CLL, but in unusual circumstances such as during the COVID-19 pandemic, short, limited course of single agent Venetoclax is a viable option of treatment to achieve durable remission.

Idelalisib (PI3Kδ inhibitor) therapy for patients with relapsed/refractory chronic lymphocytic leukemia: A Swedish nation-wide real-world report on consecutively identified patients.

We examined the efficacy and toxicity of the PI3Kδ inhibitor idelalisib in combination with rituximab salvage therapy in consecutively identified Swedish patients with chronic lymphocytic leukemia (CLL). Thirty-seven patients with relapsed/refractory disease were included. The median number of prior lines of therapy was 3 (range 1-11); the median age was 69 years (range 50-89); 22% had Cumulative Illness Rating Scale (CIRS) >6 and 51% had del(17p)/TP53 mutation. The overall response rate was 65% (all but one was partial response [PR]). The median duration of therapy was 9.8 months (range 0.9-44.8). The median progression-free survival was 16.4 months (95% CI: 10.4-26.3) and median overall survival had not been reached (75% remained alive at 24 months of follow-up). The most common reason for cessation of therapy was colitis (n = 8, of which seven patients experienced grade ≥3 colitis). The most common serious adverse event was grade ≥3 infection, which occurred in 24 patients (65%). Our real-world results suggest that idelalisib is an effective and relatively safe treatment for patients with advanced-stage CLL when no other therapies exist. Alternative dosing regimens and new PI3K inhibitors should be explored, particularly in patients who are double-refractory to inhibitors of BTK and Bcl-2.

How we approach the perioperative management of patients with chronic lymphocytic leukaemia receiving continuous cancer-directed therapies.

Historically, invasive procedures and surgeries were deferred in patients with haematological malignancies including advanced stage chronic lymphocytic leukaemia (CLL) because of limited life expectancy. However, novel, and often continuous, treatments have markedly improved outcomes in CLL. Some patients may expect years of treatment response and disease control, overcoming the short life expectancy that deters interventionalists. Such patients now often undergo various invasive procedures including major surgery. To inform peri-operative management, we summarize the relevant side effects and drug interactions of continuous CLL therapies, highlight potential surgical risks, and provide recommendations on withholding specific CLL drugs around invasive procedures.

Expression of the Tigit/CD226/CD155 Receptors/Ligand System in Chronic Lymphocytic Leukemia

Introduction: T cell immunoreceptor with Ig and ITIM domains (TIGIT) is a surface receptor mainly expressed by CD8+, regulatory T lymphocytes and natural killer (NK) cells, but not by normal B cells. It performs as an inhibitory immune checkpoint, activated through binding of CD155. TIGIT competes with CD226 for CD155 binding, resulting in opposite outcomes: while CD226 enhances cytotoxicity of T lymphocytes and NK cells, TIGIT exerts immunosuppressive effects. Whether TIGIT engagement triggers an alternative signaling cascade, or whether it simply prevents CD226 activation, remains an open point. Tumor-infiltrating T lymphocytes generally express high levels of the molecule, together with the other checkpoint inhibitor PD-1. On this basis, antagonist antibodies targeting TIGIT are under evaluation to restore immunity and treat cancer patients, alone or in various combinations. Chronic lymphocytic leukemia (CLL), the most common adult leukemia, is characterized by a highly heterogeneous clinical outcome. Several molecular markers can help in stratifying patients, including the presence or absence of somatic mutations in B cell receptor, cytogenetic aberrations and single gene mutations. Interestingly, CLL cells express several T cell specific antigens, including CD5. A previous report indicates that, in CLL, TIGIT is expressed by circulating CD4+T cells, increasing during disease progression, while nothing is known about its expression on CLL cells. Aim:This work was undertaken with the aim of studying expression of the TIGIT/CD226/CD155 axis in CLL. Methods:We assembled a cohort of 101 primary CLL samples (40% females, mean age of 61). All patients were either untreated or had not received treatment in the 6 months prior to analysis. PBMC samples were tested for expression of TIGIT, CD155 and CD226 in both T and B subsets. A multiparametric flow cytometry strategy was designed, combining anti-TIGIT, anti-CD155 and anti-CD226 antibodies with a panel of B- (anti-CD19, anti-CD5, anti-CD38, anti-CD49d and anti-CD73) and T-mono/NK specific (anti-CD3, anti-CD8, anti-CD4, anti-CD14 and anti-CD56) markers. The number of TIGIT molecules on leukemic cells was estimated by interpolating values of mean fluorescence intensity (MFI) of each sample with that of PE-Quantibrite beads. Results:CLL cells heterogeneously express surface TIGIT, ranging from 0.2 to 81% (mean value 20%, median 10%, SEM ±2.145). The estimated number of molecules per cell was in the range of 32.5-3571 (mean 1140, median 841.1, SEM ±83.6). Expression of TIGIT was independent of gender or age at diagnosis and there was no correlation between TIGIT levels and lymphocyte counts in peripheral blood. In contrast, in this cohort of untreated patients, we observed a significantly lower TIGIT expression in samples with advanced disease (RAI III-IV) compared to early stages (RAI 0-I). Accordingly, low TIGIT associated with unmutated (UM) IGHVgenes and with an unfavorable FISH profile (trisomy 12, deletion 17 and deletion 11 vs. deletion 13 or normal karyotype). Lower, although not significant, TIGIT levels were observed in NOTCH1-mutated CLL samples (n=11) compared to counterpart (n=89). Looking at the T cell population, we observed overall higher TIGIT levels in the CD8+vs CD4+subset (mean %TIGIT+cells in CD8+56.7±1.8 vs 27.2±1.3 in CD4+). In line with reported observations, we found a modest but significant increase of TIGIT+T cells in advanced stage CLLs, at variance with what observed on the leukemic B cell side. Accordingly, we observed higher percentages of TIGIT+/CD4+cells in CLL samples carrying UM IGHVgenes. CD226 and CD155 were more homogeneously expressed in all subsets without significant differences, both in CLL and T cell components. Conclusions: This work shows that CLL cells express the immunomodulatory molecule TIGIT, particularly in the early stages of the disease in untreated patients. While further studies are needed to characterize its functional implications as well as treatment effect on TIGIT expression, it is tempting to speculate that TIGIT expression by CLL cells may serve to trigger an immunosuppressive behavior in these cells, which is no longer needed when the disease becomes advanced. This observation represents a starting point for future studies investigating the role of TIGIT in CLL and hints to a possible use of anti-TIGIT antibodies to target different cellular components of the disease. Disclosures Hoofd: iTeos Therapeutics: Employment. Coscia:Abbvie: Membership on an entity's Board of Directors or advisory committees; Gilead: Membership on an entity's Board of Directors or advisory committees; Janssen: Membership on an entity's Board of Directors or advisory committees, Research Funding; Karyopharm Therapeutics: Research Funding. Gaidano:Sunesys: Consultancy, Honoraria; AbbVie: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Astra-Zeneca: Consultancy, Honoraria; Janssen: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau. Furman:Acerta Pharma: Consultancy; Beigene: Consultancy; Incyte: Consultancy; Janssen: Consultancy; Oncotracker: Consultancy; Pharmacyclics: Consultancy; Sunesis: Consultancy; TG Therapeutics: Consultancy; Verastem: Consultancy; Genentech: Consultancy; Abbvie: Consultancy; AstraZeneca: Consultancy. Deaglio:VelosBio Inc.: Research Funding; Verastem Inc: Research Funding; iTeos Therapeutics: Research Funding.

Analysis of Outcomes of Younger (≤ 55 Years) Compared with Older (> 55 Years) Patients with Chronic Lymphocytic Leukaemia (CLL) in Seven Studies Conducted By the German CLL Study Group (GCLLSG)

Analysis of Outcomes of Younger (≤ 55 Years) Compared with Older (> 55 Years) Patients with Chronic Lymphocytic Leukaemia (CLL) in Seven Studies Conducted By the German CLL Study Group (GCLLSG)

Abnormal T follicular helper cell subsets in Chronic Lymphocytic Leukemia

Abstract The B cell malignancy Chronic Lymphocytic Leukemia (CLL) is a slow progressing disease of monoclonal B cell expansion and immune dysfunction associated with recurrent infections and second malignancies. CD4+ CXCR5+ T cells, known as follicular helper T cells (Tfh), have specialized properties in promoting B cell activation but their role in CLL is unknown. Here we examine the phenotype, activation status, clinical relevance and potential function of circulating Tfh cell subsets in CLL patients. We find that the percentage of Tfh cells is significantly increased in CLL patients compared to healthy age-matched controls. Tfh frequencies are significantly increased in advanced stage CLL patients compared to early stage disease. CLL patients also exhibited different composition of Tfh1, Tfh2 and Th17 subsets and show differential expression of activation markers compared to healthy controls. Our results indicate that the Tfh1 subset is particularly activated and expanded in CLL patients with more progressive disease. Tfh subset expansion and activation correlated with specific cytokine and chemokine levels and with decline in serum immunoglobulin levels. A large proportion of CD4+ T cells in CLL bone marrow express activated Tfh1 phenotype, suggesting that these cells are present within lymphoid tissues where CLL cells proliferate. Lastly, we found that treatment of CLL patients with the Btk inhibitor Ibrutinib lead to normalization of Tfh populations and reduced Tfh activation markers. Our results indicate that Tfh subset profiles could serve as useful biomarker to evaluate the progression of CLL and suggest selective expansion of Tfh1 cells may help drive CLL proliferation and immune dysfunction.

EGR2 mutations define a new clinically aggressive subgroup of chronic lymphocytic leukemia.

Recurrent mutations within EGR2 were recently reported in advanced-stage chronic lymphocytic leukemia (CLL) patients and associated with a worse outcome. To study their prognostic impact, 2403 CLL patients were examined for mutations in the EGR2 hotspot region including a screening (n=1283) and two validation cohorts (UK CLL4 trial patients, n=366; CLL Research Consortium (CRC) patients, n=490). Targeted deep-sequencing of 27 known/postulated CLL driver genes was also performed in 38 EGR2-mutated patients to assess concurrent mutations. EGR2 mutations were detected in 91/2403 (3.8%) investigated cases, and associated with younger age at diagnosis, advanced clinical stage, high CD38 expression and unmutated IGHV genes. EGR2-mutated patients frequently carried ATM lesions (42%), TP53 aberrations (18%) and NOTCH1/FBXW7 mutations (16%). EGR2 mutations independently predicted shorter time-to-first-treatment (TTFT) and overall survival (OS) in the screening cohort; they were confirmed associated with reduced TTFT and OS in the CRC cohort and independently predicted short OS from randomization in the UK CLL4 cohort. A particularly dismal outcome was observed among EGR2-mutated patients who also carried TP53 aberrations. In summary, EGR2 mutations were independently associated with an unfavorable prognosis, comparable to CLL patients carrying TP53 aberrations, suggesting that EGR2-mutated patients represent a new patient subgroup with very poor outcome.

EGR2 Mutations in Chronic Lymphocytic Leukemia: A New Bad Player

Abstract *Contributed equally as first authors. **Contributed equally as senior authors. Recurrent mutations within EGR2, a versatile transcription factor involved in differentiation of hematopoietic cells, were recently reported in 8% of advanced-stage chronic lymphocytic leukemia (CLL) patients, where they appear to be associated with a worse outcome. EGR2 is activated through ERK phosphorylation upon B-cell receptor (BcR) stimulation, and we have previously shown that EGR2 -mutated CLL patients display altered expression of EGR2 down-stream target genes compared to wildtype (wt) patients, thereby pointing to a pathogenic role for EGR2 mutations in dysregulating BcR signaling. To gain further insight into the incidence and prognostic impact of EGR2 mutations in CLL, we screened samples from a well-characterized series of 1430 patients, either by Sanger sequencing (n=1019) or targeted deep-sequencing (n=370), both covering the recently reported EGR2 hotspot in exon 2. In addition, whole-exome data was available for an additional 43 patients. Different cohorts were included in our analysis ranging from 'general practice' CLL (33% IGHV-unmutated (U-CLL), 6% TP53 -aberrant (TP53abn), n=693), to adverse-prognostic CLL (89% U-CLL, 26% TP53abn, n=325), patients belonging to clinically aggressive stereotyped subsets #1-3 & #5-8 (n=342), patients relapsing after FCR therapy (n=41) and Richter transformed cases (n=31), thus reflecting the heterogeneous nature of CLL. Nineteen EGR2 mutations were detected by Sanger sequencing, while 22 additional mutations were identified with deep-sequencing using a 5% variant allele frequency (VAF) cutoff (median 39%, range 5.6-63.9%, median coverage 43,000X). With the exception of one in-frame deletion, all mutations were missense alterations located within the three zinc-finger domains. Significant enrichment of EGR2 mutations was observed in adverse-prognostic (18/325, 5.5%) and FCR-relapsing (4/41, 9.8%) CLL compared to the 'general practice' cohort (18/693, 2.6%, Figure 1A). A surprisingly low frequency was observed among clinically aggressive stereotyped subsets (5/342, 1.5%), although the cause for this observation is currently unknown. Finally, 2/31 (6.5%) cases with Richter transformation carried an EGR2 mutation. Of the 4 FCR-relapsing, EGR2 -mutated cases with available overtime samples, all demonstrated a significant expansion of the EGR2 -mutated clone at relapse (VAF-increase between 15-41%). In addition, subclonal levels of EGR2 hotspot mutations (VAF 0.5-5%) were detected in an additional 13/370 (3.5%) cases by deep-sequencing. The majority of EGR2 -mutated CLL patients (32/39, 82%) concerned U-CLL and the following aberrations co-occurred: 11q-deletions (n=10), TP53abn (n=6), NOTCH1 (n=3)or SF3B1 (n=3) mutations. EGR2 -mutated patients displayed a significantly worse overall survival compared to wt patients (median survival 59 vs. 141 months, p=0.003, using a conservative 10% VAF cutoff), and a poor outcome similar to cases with TP53abn (Figure 1B). In multivariate analysis (n=583), EGR2 status remained an independent factor (p=0.038), along with stage (p=0.048) and IGHV status (p<0.0001), while TP53abn and del(11q) showed borderline significant values (p=0.069 and p=0.059, respectively). To investigate the impact of EGR2 mutations in a homogeneously treated patient cohort, EGR2 mutation analysis of the UK CLL4 trial is underway. To date, 8/247 patients have been identified as EGR2 -mutated by deep-sequencing and they show a decrease of their median overall survival (42 vs. 77 months) compared to wt patients; however, this did not reach statistical significance, probably due to the low number of EGR2 -mutated cases. Final results of the UK CLL4 trial will be presented at the ASH meeting. In summary, EGR2 -mutant cases appear to constitute a novel poor-prognostic subgroup of CLL, with mutations occurring either as disease-initiating aberrations, i.e. in cases where mutations were found in the entire clone, or as subclonal driver events linked to progressive disease. The latter is reflected by the enrichment of EGR2 mutations in aggressive CLL and the association of EGR2 mutations with an overall dismal prognosis. Considering the potential role of mutated EGR2 in altering BcR signaling, it will be particularly relevant to study the efficacy of BcR inhibitors in this patient group. Figure 1. Figure 1. Figure 2. Figure 2. Disclosures Langerak: Roche: Other: Lab services in the field of MRD diagnostics provided by Dept of Immunology, Erasmus MC (Rotterdam); InVivoScribe: Patents & Royalties: Licensing of IP and Patent on BIOMED-2-based methods for PCR-based Clonality Diagnostics.; DAKO: Patents & Royalties: Licensing of IP and Patent on Split-Signal FISH. Royalties for Dept. of Immunology, Erasmus MC, Rotterdam, NL. Schuh:Acerta Pharma BV: Research Funding. Strefford:Roche: Research Funding.

Effects Of Bendamustine Plus Rituximab On The Distribution Of Normal Peripheral Blood Leucocyte Populations In Advanced-Stage Chronic Lymphocytic Leukemia (CLL)

IntroductionManagement of B-cell chronic lymphocytic leukemia (CLL) is currently undergoing profound changes. Accordingly, new treatment options with an expected less toxicity than standard regimens are been explored. Recent results show that chemoimmunotherapy may improve the life expectancy of CLLpatients and has proven to be more efficient than chemotherapy alone in depleting malignant cells. Despite its efficacy, little is known about its precise immunomodulatory effects. AimTo evaluate the effects of chemoimmunotherapy with bendamustine plusrituximab (BR) on the distribution of normal residual leucocyte populations in peripheral blood (PB) from advanced-stage CLL patients, with special emphasis on maturation-associated B-cell subsets (immature, naïve, memory IgM/IgG/IgA and plasma cells). Material and MethodsDistribution of PB neoplastic cells and residual normal immune cell subpopulations were analyzed in 72 CLL patients with advanced disease (Binet B/C), before therapy (M0) and after 1 course of BR (M1). The same analysis was repeated 3 months after completing treatment (M3) in 31/72 patients. PB leucocyte cell subsets were identified at each time-point by 8-color flow cytometry with monoclonal antibody reagents against CD3, CD4, CD5, CD8, TCRgd, CD19, CD20, CD27, CD38, CD45, CD56, sIgM, sIgA, sIgG, sIgLambda and sIgKappa. ResultsAfter the first BR course, absolute counts of all PB myeloid subsets were significantly decreased as compared to time M0, including neutrophils (2,744±1,830 vs 4,764±2,906 cells/uL, p<0.001), eosinophils (132±185 vs 215±245 cells/uL; p<0.001), basophils (37±28 vs 59±47 cells/uL, p<0.001), monocytes (334±280 vs 504±424 cells/uL, p=0.001) and dendritic cells (DCs, 41±40 vs 89±168 cells/uL, p=0.02), as well as NK cells (120±147 vs 550±599 cells/uL, p<0.001). At M3, all these populations remained decreased when compared to M0, but at similar levels to M1 (except for the absolute number of DCs, found to be increased vs. M1 -74±46 vs 41±40 cells/uL, p=0.008- and closer to M0).In turn, total T cells were reduced in M1 as compared to M0 values (818±655 vs 3,905±2,375 cells/uL, p<0.001), due to decreased numbers of CD4+ (424±376 vs 1,573±1,204 cells/uL, p<0.001), CD8+ (342±330 vs 1,334±1,218 cells/uL, p<0.001) and TCRgd (21±28 vs 141±289 cells/uL, p=0.001) T cells, leading to an increased CD4/CD8 ratio (1.8±1.3 vs 1.4±0.8, p=0.004). Also, decreased levels of CD4 (222±156 cells/uL), CD8 (501±544 cells/uL) and TCRgd (21±40 cells/uL) T cells were observed at time M3 vs. baseline values. No changes (p>0.05) were observed for CD8 and TCRgd for M3 vs. M1, while CD4+ T-cell numbers were significantly reduced (p=0.006), resulting in an inverted CD4/CD8 ratio (0.9±1.0 vs. 1.8±1.3, p=0.005) at the M3 time-point.As regards B cells, the absolute count of both neoplastic and normal B lymphocytes were significantly decreased at time M1 vs. M0 (3,363±9,353 vs 53,521±56,602 CLL cells/uL and 2±6 vs 58±107 normal B-cells/uL, p=0.006 and p<0.001, respectively). Within the normal residual B-cell compartment, we found significantly decreased numbers of immature (0.07±0.22 vs 6.55±21.64 cells/uL, p=0.01) and memory (1.3±14.7 vs 35.1±43.6 cells/uL, p<0.001) B cells -including sIgM (0.5±2.3 vs 14.5±24.8 cells/uL, p<0.001), sIgG (0.2±1.0 vs 11.5±17.2 cells/uL; p<0.001) and sIgA (0.6±3.1 vs 9.5±12.5 cells/uL, p<0.001) memory B cells-. At time M3, decreased (p<0.01) naïve (0.46±2.58 cells/uL) and memory B-cells (1.34±6.75 cells/uL), including IgM (0.46±2.58 cells/uL), IgG (0.34±1.69 cells/uL) and IgA (0.09±0.31 cells/uL), but not immature cells (2.28±8.84 cells/uL, p=0.9), were observed as compared to time M0. Differences did not reach statistical significance when comparing M3 vs. M1. The number of circulating plasma cells did not significantly vary during treatment. ConclusionsAll PB leucocyte subsets are affected by BR treatment in advanced-stage CLL. Interestingly, at time M3 the CD4+ T-cell subset continues to be decreased, while the other T-cell compartments seem to remain stable. Also, normal B cells are affected by BR treatment, and the depletion induced after one course therapy is maintained even three months after finishing BR therapy, except for immature B cells, that seem to be the first to recover in PB. Further studies will offer a more accurate insight into the biology of cell recovery during and after BR therapy in CLL patients. Disclosures:No relevant conflicts of interest to declare.

Alterations Of The Chemokine Microenvironment In Chronic Lymphocytic Leukemia

BackgroundIn chronic lymphocytic leukemia (CLL), proliferation of the leukemic cell clone occurs in the bone marrow and lymphatic tissues rather than peripheral blood. In this microenvironment, CLL cells interact with accessory cells, such as T-cells and CD68+ nurselike cells (NLCs). In addition, cytokines and chemokines secreted by leukemic cells, stromal cells and T-cells are essential in forming the disease-specific microenvironment. However, the exact biological role of cytokines and chemokines needs to be defined. MethodsIn order to address this issue, we measured serum levels of 20 chemokines and cytokines in a prospective cohort of 159 previously untreated Binet stage A patients (pts) (GCLLSG CLL1 trial), 50 pts with advanced CLL in need of first line treatment (GCLLSG CLL8 trial) and 27 healthy individuals. For the study cohorts, serum samples had been centrally collected at study entry and stored at -80°C. Sera were analyzed on a Luminex-based multiplex platform, allowing simultaneous screening of multiple serum parameters. ResultsSerum levels of 13 chemokines (EGF, MCP-1, MIP-1alpha, MIP-1beta, sIl2Ralpha, VEGF, MCP-2, MCP-4, SDF-1, 6CKine, CTACK, TRAIL, SCF) differed significantly between healthy controls and CLL patients (p<0.05), indicating that the expression of these cytokines may potentially impact pathways common to CLL and the disease specific microenvironment. In addition, 7 chemokine serum levels were significantly higher in advanced stage CLL compared to patients at primary diagnosis, indicating a pronounced shift of the chemokine homeostasis upon disease progression. (Table)TableMedian chemokine serum levels in healthy individuals and patients with early (CLL1 cohort) and advanced (CLL8 cohort) CLLMedian serum level (pg/ml)Healthy controlCLL1CLL8MIP-1beta116266196p<0.001sIl2Ralpha215042255p<0.001TNFalpha124080p=0.008Il-10319p=0.001IL-1655203425p=0.0136CKine319307764p<0.001SCF107955p=0.001We identified a strong correlation of inflammatory cytokines (TRAIL, TNFalpha; p=0.039), growth factors (EGF, VEGF, TPO, SCF; p<0.001) and chemokines involved in B- and T-cell migration and homing (MIP-1alpha, MIP-1beta, 6CKine, Il-16; p<0.05). These coordinately regulated cytokines may reflect pathways important to the pathobiology of CLL. Hierarchical cluster analyses revealed distinct chemokine expression patterns in healthy individuals, early CLL and advanced stage disease. Finally, sIl2Ralpha has been previously confirmed as an independent prognostic factor in early stage CLL ConclusionDue to the comparison of 27 healthy individuals and 209 CLL pts we were able to demonstrate that the chemokine homeostasis is significantly altered in CLL compared to healthy individuals. Chemokines involved in B- and T-cell migration and homing and recruitment, inflammation and growth factors are coordinately overexpressed, pointing towards pathways crucial to the formation of a disease specific microenvironment. These pathways might serve as potential targets for future therapeutic strategies. Disclosures:No relevant conflicts of interest to declare.

Impact Of The Number Of Prior Treatment Lines Received On The Distribution Of Peripheral Blood Leukocyte Subsets In Advanced-Stage B-Cell Chronic Lymphocytic Leukemia (CLL)

AbstractIntroduction It is currently well-known that B-cell chronic lymphocytic leukemia (CLL) patients have an impaired immune function -particularly in advanced disease-, which significantly contributes to a higher risk of infections. The introduction of new effective therapeutic agents, such as the purine analogues (or alkylating agents with concomitant properties of purine analogues) plusanti-CD20 monoclonal antibodies, have significantly increased the rate of complete responses in CLL, but so far their impact on the overall immune function and the spectrum of infections occurring in CLL patients after therapy, remains to be fully understood. AimTo evaluate the effect of the number of treatment lines received on the different normal circulating leucocyte cell populations, including normal B-cell subsets, in advanced-stage treated CLL. Material and MethodsThe distribution of peripheral blood (PB) leukocytes was analyzed in 85 untreated CLL patients, and compared to that of 63 patients who had previously been treated with 1 line of treatment (n=39) or >1 line of treatment (n=24), and who failed to respond. Analysis was performed by 8-color flow cytometry with monoclonal antibodies against CD3, CD4, CD5, CD8, TCRgd, CD19, CD20, CD27, CD38, CD45, CD56, sIgM, sIgA, sIgG, sIgLambda and sIgKappa. ResultsThe absolute count of circulating malignant B cells was not significantly different (p>0.05) in the untreated vs. previously treated patients who received 1 or >1 line of treatment (77,627±84,211 vs 67,994±72,087 vs 59,282±74,206 cells/uL; respectively). In contrast, as compared to untreated patients, PB normal B cells were found to be reduced in patients who had received either 1 line or >1 line of treatment (89±142 vs 36±57 and 23±32 cells/uL, p=0.004 and p<0.001, respectively), but at similar levels between the two groups of previously treated patients (p>0.05). When dissecting the normal B-cell subsets, therapy-related decreased B-cell numbers were mostly due to a reduced number of circulating memory B cells (67±98 vs 21±45 and 15±26 cells/uL; p=0.001 and p<0.001, respectively), including all memory isotypes: IgM (24±31 vs 5±13 and 5±6 cells/uL, p<0.001), IgG (25±59 vs 10±32 and 6±13 cells/uL; p=0.008) and IgA (18±30 vs 5±10 and 6±12 cells/uL; p=0.001 and p=0.003). No significant differences were found as regards the absolute count of immature (5±11 vs 8±26 and 3±11 cells/uL; p>0.05) and naïve (16±55 vs 6±18 and 4±8 cells/uL; p>0.05) B cells, nor for circulating plasma cells (3±18 vs 5±21 and 2±6 cells/uL; p>0.05), regardless of the therapy status.As compared to untreated patients, the absolute count of CD4+ T cells and CD4/CD8 double negative TCRαβ cells were significantly lower in patients with >1 line of treatment (1,836±1,340 vs 1,256±1,027 and 131±165 vs 56±97 cells/uL, p=0.03 and p=0.007 respectively) but not in those who had received only 1 line (1,477±1,349 and 201±747 cells/uL; p>0.05). In contrast, therapy did not show a significant impact on the absolute count of PB T CD8+ and TCRgd cells. No statistically significant differences were observed in the number of PB innate immune subpopulations including, neutrophils, eosinophils, basophils, monocytes, NK cells and dendritic cells. ConclusionsWhile there are no differences regarding the number of leukemic cells, previously treated patients have significantly reduced counts of total and memory (all isotypes) normal B-cell subsets when compared to untreated patients. Together with this, CD4+ helper T cells could also be compromised after more than 1 line of treatment. Monitoring of these therapy-related immune defects could contribute to a better management of infectious complications in advanced-stage CLL patients. Disclosures:No relevant conflicts of interest to declare.

Combined Patterns of IGHV Repertoire and Cytogenetic/Molecular Alterations in Monoclonal B Lymphocytosis versus Chronic Lymphocytic Leukemia

BackgroundChronic lymphocytic leukemia (CLL)-like monoclonal B lymphocytosis (MBL) with (MBLhi) or without (MBLlo) absolute B-lymphocytosis precedes most CLL cases,the specific determinants for malignant progression remaining unknown.Methodology/Principal FindingsFor this purpose, simultaneous iFISH and molecular analysis of well-established cytogenetic alterations of chromosomes 11, 12, 13, 14 and 17 together with the pattern of rearrangement of the IGHV genes were performed in CLL-like cells from MBL and CLL cases. Our results based on 78 CLL-like MBL and 117 CLL clones from 166 subjects living in the same geographical area, show the existence of three major groups of clones with distinct but partially overlapping patterns of IGHV gene usage, IGHV mutational status and cytogenetic alterations. These included a group enriched in MBLlo clones expressing specific IGHV subgroups (e.g. VH3-23) with no or isolated good-prognosis cytogenetic alterations, a second group which mainly consisted of clinical MBLhi and advanced stage CLL with a skewed but different CLL-associated IGHV gene repertoire (e.g. VH1-69), frequently associated with complex karyotypes and poor-prognosis cytogenetic alterations, and a third group of clones with intermediate features, with prevalence of mutated IGHV genes, and higher numbers of del(13q)+ clonal B-cells.Conclusions/SignificanceThese findings suggest that the specific IGHV repertoire and IGHV mutational status of CLL-like B-cell clones may modulate the type of cytogenetic alterations acquired, their rate of acquisition and/or potentially also their clinical consequences. Further long-term follow-up studies investigating the IGHV gene repertoire of MBLlo clones in distinct geographic areas and microenvironments are required to confirm our findings and shed light on the potential role of some antigen-binding BCR specificities contributing to clonal evolution.

Combination therapy of Fludarabine and Cyclophosphamide(FC) Combination Regimen in advance stage of Chronic Lymphocytic Leukemia

Background: the exposure of chronic lymphocytic leukemia (CLL) cells to fludarabine and cyclophosphamide resulted in an increased, synergistic cytotoxicity . DNA repair mechanisms in CLL cells, which are initiated in response to cyclophosphamide exposition, are inhibited by fludarabine. This observation was later translated into clinical trials evaluating the combination of fludarabine plus cyclophosphamide (FC) showed promising efficacy with response rates exceeding 90% in previously untreated and pretreated patient&#x0D; Aim of this study: To assess the efficacy and safety of combination therapy of fludarabine plus cyclophosphamide in Iraqi adults patients with advance stage of chronic lymphocytic leukemia (CLL) in both previously treated and untreated patients and to assess the treatment free and overall survival in CLL patient who are receiving FC regimen therapy.&#x0D; Patients and methods: Single arm study was done between February 2005 and fabruary2009.This study included 64 Iraqi patients aged between 39-77years old with advanced stage CLL .All patients received FC combination Therapy(fludarabine25mg/m2 plus cyclophosphamide 250mg/m2 for 3 days intravenously, repeated every 28 days). Treatment was administered for 4-6 courses. Forty eight(75%) patients were treatment naive(N) and 16(25%)were previously treated(Y) with alkylating agent.&#x0D; Results: This combination chemotherapy resulted in 39.1% complete remission rate(CR) and 39.1%partial remission(PR) rate with overall response rated78.2%.The 2years median treatment-free survival was 90% with the median duration of response was 18months. Also there was a significant difference(p value &lt;0.005) between different stage group(C&amp;B) and degree of response, with better response rate in those with stage C than those with stage B, as the overall response rate was 88.3% and 65.5% respectively.&#x0D; By common toxicity criteria (CTC) grading, the major toxicity(grade 3-4) in patients who treated by FC regimen were nausea and vomiting while the myelosuppression was prominent complication of grade 1&amp;2 as leucopenia and neutropenia occur in 19%, 14% respectively however this is not increased the number of severe infections.&#x0D; Conclusion: Fludarabine and cyclophosphamide combination regimen is an effective therapy for patients with advance CLL with high response and complete remission rate in those untreated and pretreated CLL patients, with good tolerability to this combination&#x0D;

Efficacy and Tolerance of Fludarabine and Cyclophosphamide ( FC ) Combination Regimen in Advance Stage of Chronic Lymphocytic Leukemia = فعالية و تحمل الجمع بين علاج الفلودارابين مع السيكلوفوسفاميد في علاج المراحل المتقدمة من ابيضاض الدم اللمفاوي المزمن

Background: based on data suggesting synergistic activity of fludarabine (F) and cyclophosphamide (C) combination therapy. This study was conducted to assess the efficacy and tolerability of this combination chemotherapy in Iraqi adult patients with advanced chronic lymphocytic leukemia (CLL), reflected by better response rate, treatment free survival and overall survival benefit. Patient and Methods: A prospective study carried out in Baghdad teaching hospital and national hematology center in Baghdad between February 2005 and fabruary 2009. It included 64 Iraqi patients aged between 39-77 years old with advanced stage CLL. Written informed consent wasobtained from all patients prior to start of therapy. They received FC combination therapy (fludarabine 25 mg/ m2 plus cyclophosphamide 250mg/ m2 for 3 days intravenously, repeated every 28 days). Treatment was administered for 6 courses. Results: Out of 64 CLL patients with Binet stage B&C who were included in this study, 41(64.1%) patients were male and 23 (35.9%) patients were females (M:F ratio1.7:1) with median time of follow-up 26 months. median age was 59.9 years. Forty- eight (75%) patients were previously untreated, of them 22 (45.8%) patients were stage B and 26 (45.1%) patients were stage C while the other 16 (25%) patients with CLL were previously treated with an alkylating agents, of them 7(43.7%) of stage B and 9 (56.2%) with stage C. This combination chemotherapy resulted in 39.1% complete remission and 39.1% partial remission. The two years median treatment-free survival was 90% with the median duration of response was 18 months. there was a significant difference (p<0.005) between the different Binet stage group (C&B) and degree of response, with better response rate in those with stage C than those with stage B. the overall response rate was 88.5%, 65.5% for stage C and B respectively.The major toxicity (grade 3-4) were nausea and vomiting while the myelosupression of grade 1&2 for leucopenia and neutropenia occur in 19%, 14% respectively. Conclusion: Fludarabine and cyclophosphamide combination regimen is an effective therapy for patients with advance CLL with high response and complete remission rate in those untreated and previously treated CLL patients, with good tolerability to this combination.

Multicentre Phase I Study with an 8-Dose Regimen of Single Agent Anti-CD20 Monoclonal Antibody LFB-R603 in Patients with Relapsed Chronic Lymphocytic Leukemia (CLL)

Abstract 2862 Background:LFB-R603 is a next generation anti-CD20 monoclonal antibody (mAb) with an optimised glycosylation profile resulting in high antibody-dependent cellular cytotoxicity. A weekly × 4 dose regimen of LFB-R603 has been found to induce rapid, profound and sustained blood lymphocyte depletion in patients (pts) with advanced stage CLL in a multicentre first-in human dose-escalation phase I study*. Aims:A second part of the phase I study designed to evaluate a weekly × 8 dose regimen was initiated in April 2010. Objectives were to assess the safety, pharmacokinetics and potential efficacy of LFB-R603 in pts with CLL relapsing after at least one prior course of therapy with fludarabine. Methods:Twelve pts were included. A flat dose of LFB-R603 was administered once a week for 8 weeks consisting of an initial dose of 150 mg followed by 7 doses of 450 mg (total dose 3300 mg). Premedication consisted of allopurinol, dexchlorpheniramine and acetaminophen, combined with methylprednisolone 1mg/kg before the first two infusions. Results:Median age was 69.5 years [62–77], median time from diagnosis to inclusion was 10.4 years [4.0–23.6], number of prior therapies was 3 [1–8]. Seven pts received at least one prior rituximab-containing regimen (median number was 1 [1–3]). Two pts presented with 17p deletion. Bulky (>5cm) lymph node enlargement was observed in 4 pts, splenomegaly in 9 pts, and hepatomegaly in 4 pts. Median WBC count at baseline was 48.5×109/l [9.9–154.2], hemoglobin 11.9 g/dl [7.3–14.0] and platelets 102×109/l [13–193]. Median lymphocyte bone marrow infiltration was 85% [40–94]. Pharmacokinetic (PK) data showed an increase of mean Cmax, AUC¥ and t1/2 term from the first to the eighth infusion from 23.4 to 220.5 mg/L, 732 to 50, 760 mg.h/L, and 13.4 to 147.8 h, respectively whereas mean CL decreased from 424 to 38.6 mL/h.Median lymphocyte counts and relative circulating lymphocyte depletions from baseline at D8, D29, M2, M 4, and M 6 are presented in the table below.TimeD1D8D29D57M4M64Lymphocyte count146.616.01.51.81.42.0Lymphocyte depletion2NA3−57.4%−93.8%−92.3%−91.4%−88.8%1×109/l2%3Not Applicable4n=8 pts.Response was evaluated at month 4 according to updated NCI-WG guidelines. Among 11 evaluable pts, overall response rate was 45% (5/11) corresponding to 5 pts in durable partial response (PR). Two additional pts were in PR at month 4 not confirmed 2 months later and 4 pts were in stable disease. Pts with 17p deletion and/or bulky tumor were in stable disease.All pts but one received the planned 8 infusions without any dose reduction. One patient was prematurely withdrawn from the study due to a concomitant secondary leukemia diagnosed after the 2nd infusion of LFB-R603. Interim safety data indicate that all pts presented with at least one drug-related adverse event (AE). Forty percent of the AEs were related to the first infusion, 18% to the second, and 21% to the subsequent infusions. The most frequent (> 10%) drug-related AEs were infusion related reactions (IRR) (75% of the pts, including 33% of pts with grade 3 (CT-CAE v3.0) IRR), neutropenia (58%; 33% with grade 3 and 25% with grade 4), grade 1–2 pyrexia (42%), grade 1–2 thrombocytopenia (42%), grade 1–2 infections (25%), chills (17%), asthenia (17%), and grade 3 hepatic cytolysis (17%). One pt experienced a grade 4 drug-related pancytopenia. All AEs were reversible spontaneously or with supportive care intervention. Conclusion:LFB-R603 induces a promising 45% of ORR in pts with advanced stage CLL at a relatively low dose regimen. PK data indicates that the dose and the schedule of administration could be optimized. Toxicity of LFB-R603 is manageable and makes possible a combination with chemotherapy. Disclosures:Cazin:LFB Biotechnologies: Honoraria. Leprêtre:LFB Biotechnologies: Honoraria. Coiffier:LFB Biotechnologies: Honoraria. Cartron:GSK: Honoraria; Roche: Consultancy, Honoraria; LFB: Honoraria. Sadoun:LFB Biotechnologies: Employment. Segaud:LFB Biotechnologies: subcontractor. Ribrag:LFB Biotechnologies: Honoraria, Research Funding.

Consolidation Therapy with Subcutaneous Alemtuzumab After Induction Treatment with Oral FC (Fludarabine and Cyclophosphamide) in Previously Untreated Patients Aged 65–70 Years with Advanced Stage Chronic Lymphocytic Leukemia (CLL): Final Results of a Phase II Study From the FCGCLL/WM,

Abstract 3900Current treatment approaches in CLL aim at achieving the best clinical response without detectable minimal residual disease (MRD) in order to prolong the duration of response and potentially overall survival. Such a goal could be achieved by combining chemotherapy and monoclonal antibodies. This phase II trial was designed to evaluate the safety and the efficacy of alemtuzumab given as consolidation therapy after 3 courses of oral FC (F 40 mg/m2 and C 250 mg/m2 D1 to D3 every 4 weeks) in patients (pts) aged 65 to 70 years with previously untreated Binet stage B or C CLL. Pts who had achieved either complete response (CR) or partial response (PR) after FC were eligible for consolidation with alemtuzumab. Alemtuzumab was administered subcutaneously (SC) at the dose of 10 mg thrice a week for 8 consecutive weeks. CMV antigenemia was monitored every week and alemtuzumab should be discontinued in pts with more than 3 positive nuclei. Such stringent stopping rules for CMV reactivation, as well as the limitation of FC regimen to 3 courses and of the duration of alemtuzumab treatment to 8 weeks, were adopted in this trial targeting elderly patients in their first line treatment because of the severe infectious toxicities reported by others with similar strategies. MRD was evaluated by 6 color flow cytometry before, during and after alemtuzumab treatment and all samples were centralized in one center (RL & FC).From June 2004 to January 2008, 55 patients with advanced (stage B or C) fully annotated CLL have been recruited in 14 french centers. Response to induction is evaluable in 51 of them (suicide before FC 1 pt and missing data 3 pts). A CR was achieved in 18 pts (34.6%) and a PR in 22 pts (42.3%) for an overall response rate (ORR) of 77% after 3 courses of FC. FC regimen was discontinued in 6 pts (progression 1 pt, renal carcinoma 1 pt, neutropenia 2 pts, PRCA 1 pt, myocardial infarction 1 pt) and a stable disease was observed in 5 pts. All the responding pts except two of them (onset of breast cancer in one CR pt and of lung carcinoma in one PR pt) proceeded to alemtuzumab consolidation after a planned 2 month period of rest (median 63 days, range 33 to 152). Alemtuzumab treatment was fully completed in 29/38 pts (76%) while it has been stopped prematurely (mainly between the 6th and 8th weeks) in 9 pts (24%). CMV reactivation occurred in 8 pts (21%) but it was associated with systemic symptoms in only one case (febrile pneumonia). A grade 3–4 neutropenia was observed in 9 pts at some point during alemtuzumab treatment. Eleven of the 21 PR pts (52%) converted from PR to CR after alemtuzumab consolidation while 2 patients went down from CR to PR. Overall, 26 pts were in CR after the whole treatment strategy (FC followed by alemtuzumab) accounting for 51% of the entire cohort. Blood MRD could be assessed sequentially in roughly two thirds of pts. While all patients but one (33/34 pts) were MRD positive after chemotherapy and before alemtuzumab treatment, only 8/22 pts (36%) had detectable MRD at the sensitivity level of 10-4 after the end of alemtuzumab consolidation, and 12 out of the 25 assessed pts (48%) still had undetectable MRD at 6 months after the end of treatment. With a median follow up of 34 months (range 2 to 58), only 6 out of the 38 pts (16%) who received FC followed by alemtuzumab consolidation, had CLL disease progression. Five patients have died but only one from CLL (solid tumors 3 pts, stroke 1 pt). No serious delayed infectious complication was observed and two patients developed auto-immune cytopenia (AIHA 1 pt and ITP 1 pt). Because of the few number of events (disease progression) observed so far, no correlation between the duration of response and the MRD data could be done by now.In conclusion, three courses of FC only yielded a rather high response rate in previously untreated elderly CLL patients and a short (8 weeks) alemtuzumab consolidation course could thereafter be administered safely, leading to a high rate of PR to CR switches, a high proportion of patients with undetectable blood MRD after the end of treatment and durable responses. Disclosures:Cazin:LFB Biotechnologies: Honoraria. Cymbalista:Roche (d) Mundipharma (e) Genzyme (e): Honoraria, Research Funding.

Kinetics of Engraftment and Predictors of Outcome in Patients with Advanced Chronic Lymphocytic Leukaemia (CLL) After Treatment with Low Dose Total Body Irradiation (TBI) Followed by related or unrelated hematopoietic Stem Cell Transplantation

Abstract 4532 Introduction:In an unicenter analysis we investigated the impact of allogeneic hematopoietic cell transplantation (RIC-HCT) after reduced intensity conditioning on the kinetics of engraftment and predictor of outcome in 50 patients with advanced CLL. Patient and Methods:Patients in advanced stage CLL (n=50) received Fludarabine 30mg/m2 on day -4 to -2 and 2Gy TBI on day 0 followed by cyclosporine and MMF from unrelated (n=40) or related (n=10) donors between June 1999 and March 2010 at the University of Leipzig. The majority of patients (n= 35) were male, had Binet C (n=37, 74%) at RIC-HCT. The median age was 58 (range 44–69) years. Of 48 patients for whom cytogenetic analyses were available, 22 (46%) had unfavourable cytogenetics including del 17 or del 11q. Three (6%) patients had CR, 27 (54%) PR, 7 (14%) progressive disease, 12 (24%) stable disease and one (5%) relapse at RIC-HCT. Resistance to first line therapy was present in 25 (50%) patients, whereas 12 (24%) were resistant to Fludarabine. Richter's transformation was found in six patients (12%). Chimerism was detected in bone marrow and peripheral blood on T-lymphocytes and B-lymphocyte subpopulation after sorting at monthly intervals in the posttransplant period and than in 6 months interval. Results:Hematological toxicities after RIC-HCT were moderate. The majority of patients (96%) engrafted with neutrophiles >500/μ L median at day 22 after HCT. Six (12%) and 15 (30%) patients maintained absolute neutrophil counts (ANC) >0,5 × 109/L and platelet counts >50 × 109/L, respectively. T-cell donor chimerism increased to >95% at day 56 and B-cell donor chimerism to 94% at day +360, respectively. B-CLL cells disappeared completely on day +360 (median 0%). Overall survival (OS) at 4 years was 51%, Non relapse related mortality (NRM) 30%, Progression-free survival 33% and progression/relapse 37%. The most common causes of NRM were GvHD (n= 7; 14%) and sepsis (n=3, 6%). Factors significantly associated with increased risk of relapse/progression were intermediate/advanced disease vs. CR/PR1 (p=0.022) and lymphocytes ≥ 5 × 109/L vs. < 5 × 109/L (18% vs. 58%, p= 0.00) at 12 months in univariate analysis. Conclusion:Full donor T-cell chimerism was reached early after HCT, while B-cell reconstitution was observed only 1.5 years after RIC-HCT despite the absence of evident disease by 360 days after RIC-HCT. Best predictor for Progression-free survival (PFS) was CR or PR1. Disclosures:Pönisch:Mundipharma: Honoraria, Research Funding.

Ofatumumab in advanced stage chronic lymphocytic leukaemia: results of the UK named patient compassionate use programme

Ofatumumab in advanced stage chronic lymphocytic leukaemia: results of the UK named patient compassionate use programme

Overall Survival Advantage and Acceptable Safety Profile with Fludarabine In Combination with Alemtuzumab (FluCam) In Previously Treated Patients with Advanced Stage Chronic Lymphocytic Leukemia

Abstract 919 Background: Patients (pts) with Rai Stage III/IV CLL have a shorter median survival compared to Rai Stage I/II pts. We previously reported significant improvement in progression-free survival (PFS) with FluCam compared to single-agent fludarabine (Flu) in pts with previously treated CLL (Engert ASH 2009; EHA 2010). Here we report the efficacy and safety of FluCam and Flu in a subset of these pts with advanced stage CLL. Methods: In a Phase 3, multi-center, controlled trial, pts with relapsed/refractory CLL were randomized to receive either IV Flu 25 mg/m 2 on days 1–5 every 28 days or IV alemtuzumab (Cam) in combination with IV Flu (FluCam). Prior to cycle 1, FluCam pts were required to undergo Cam escalation (3 mg, 10 mg, 30 mg); once the 30 mg dose was tolerated, pts began cyclic administration of Flu 30 mg/m 2 IV and Cam 30 mg IV on days 1–3 every 28 days. Pts could receive up to 6 cycles of either therapy depending on response and toxicity. Randomization was accomplished utilizing the minimization method to ensure balance between treatment arms with respect to study center, disease status, prior therapy, Rai Stage, age, gender, and lymph node size. All pts received prophylaxis with cotrimoxazole and famciclovir until CD4+ counts were >200 cells/mcL. The primary endpoint of the study was PFS with FluCam compared to Flu. A pre-specified subgroup analysis in Rai Stage III/IV pts compared PFS, overall response rate (ORR=CR + PR), complete response rate (CR), overall survival (OS) and safety in FluCam vs Flu treated pts. Differences in PFS between the 2 treatment arms were tested using the log-rank test. Results: Of the 335 pts enrolled in this study, 123 (37%) were Rai Stage III or IV (61 FluCam pts, 62 Flu pts). For the overall study population, FluCam significantly prolonged PFS compared with Flu (24.1 months (mos) vs 15.4 mos, respectively; p = 0.002; HR: 0.618; 95% CI 0.46–0.83). Data presented herein focus on the subgroup of CLL pts with Rai Stage III/IV disease. Demographics for this subset of FluCam vs Flu treated pts include: median age (65 yrs [36-80] vs 64 yrs [46-80]); gender (70% male vs 61% male); and prior Flu exposure (10% vs 8%) respectively. Pts received a median of 6 cycles in the FluCam arm and a median of 5 cycles in the Flu arm. FluCam significantly prolonged PFS compared with Flu (24.5 mos vs 11.8 mos, respectively; p Conclusion: Data presented in this subset analysis of Rai Stage III/IV CLL pts demonstrate a survival advantage, longer PFS and improved ORR/CR in pts treated with FluCam compared to Flu. The safety profile of FluCam in pts with advanced stage was acceptable and in most respects, comparable to the Flu alone arm. Overall, FluCam is a compelling treatment option in pts with previously treated advanced CLL. Disclosures: Engert: Genzyme: Honoraria, Membership on an entity9s Board of Directors or advisory committees, Research Funding. Off Label Use: Alemtuzumab (Campath, MabCampath) is indicated for the treatment of CLL. This trial examined the use of alemtuzumab in combination with fludarabine monophospate. Gercheva: Genzyme: Honoraria, Membership on an entity9s Board of Directors or advisory committees, Research Funding. Pilipenko: Genzyme: Honoraria, Membership on an entity9s Board of Directors or advisory committees, Research Funding. Robak: Genzyme: Honoraria, Membership on an entity9s Board of Directors or advisory committees, Research Funding. Wu: Genzyme: Employment, Equity Ownership. Sirard: Genzyme: Employment, Equity Ownership. Elter: Genzyme: Honoraria, Membership on an entity9s Board of Directors or advisory committees, Research Funding.

A Phase I study of LFB-R603, a Novel Anti-CD20 Antibody, in Patients with Relapsed Chronic Lymphocytic Leukemia (CLL)

AbstractAbstract 2447 Background:LFB-R603 is a chimeric anti-CD20 monoclonal antibody with an optimised glycosylation profile leading to a high binding affinity for the FcγRIIIa receptor and a stronger antibody-dependent cellular cytotoxicity (ADCC) than rituximab, particularly against tumor cells that express low CD20 levels. As a result, LFB-R603 represents a drug candidate in patients (pts) with CLL. Aims:An open-label, multicentre, first-in-human study using escalating doses of LFB-R603 was initiated in November 2008 to assess the safety, pharmacokinetics and potential efficacy of LFB-R603 in pts with CLL relapsing after at least one prior course of therapy with fludarabine. Methods:Twenty one patients were included in 5 dose cohorts. Pts received infusions of LFB-R603 as a flat dose once a week for 4 weeks. The dose was escalated based on safety in a 3+3 design. Total dose of LFB-R603 was 75 mg in cohort A (5–10-20–40 mg), 200 mg in cohort B (20–60×3 mg), 510 mg in cohort C (60–150×3 mg), 1050 mg in cohort D (150–300×3 mg) and 1650 mg in cohort E (300–450×3 mg). Premedication consisted in allopurinol, dexchlorpheniramine and paracetamol, combined with methylprednisolone 1mg/kg before the first two infusions. Results:Six pts were included in cohorts A and E and 3 in cohorts B, C and D. Median age was 62 years [43–76], median time from diagnosis was 8.3 years [2.5–14.0], number of prior therapies was 3 [1–6]. Twelve pts (57%) received at least one prior rituximab-containing regimen. Three pts presented with 17p deletion. Median WBC count at baseline was 31.0×109/l [9.3–218.4], hemoglobin 13.0 g/dl [9.1–16.0] and platelets 109×109/l [42–344].Mean lymphocyte counts and mean relative circulating lymphocyte depletions from baseline at day8, day29, and month2 in the 21 pts are presented in the table below. At month 4, lymphocyte depletions were 80% and 78% in cohorts C and E, respectively.Response was evaluated 3 months after completion of therapy (month 4) according to updated NCI-WG guidelines. Among 18 evaluable pts, overall response rate was 27% (5/18). corresponding to 5 pts in partial response (PR). Seven pts were in stable disease and 6 in progressive disease. Three patients out of 5 were confirmed in PR at month 6.All the patients received the planned 4 infusions without any dose reduction. Preliminary safety data indicate that all the pts reported at least one drug-related adverse event (AE). Most of the AEs (52%) occurred less than 48 hours after LFB-R603 infusion and 35% of the AEs occurred after the first infusion. The most frequent drug-related AEs were pyrexia (62% of the pts), infusion related reactions (IRR)(48%), transient neutropenia (38%), headache (33%), chills (29%), infections (29%), thrombocytopenia (24%) and reversible hepatic cytolysis (19%) Twelve pts experienced grade 3 (CT-CAE v3.0) drug-related AEs (IRR; allergy; infection; neutropenia; hepatic cytolysis; pancytopenia), 5 of them in cohort E, and 5 pts experienced grade 4 drug-related AEs (infection; neutropenia; pancytopenia), 2 of them in cohort E. In contrast with the first dose of 300 mg which was worse tolerated than lower doses, the maximum subsequent dose of 450 mg was well tolerated. Conclusion:LFB-R603 can induce rapid, profound and sustained lymphocyte depletion in pts with advanced stage CLL. Toxicity of LFB-R603 is manageable. Most of the drug-related AEs are related to the first infusion, probably due to cytokines release. LFB-R603 is clinically active in pts with relapsed CLL and induces partial remissions. An ongoing part 2 of this study will examine the clinical efficacy of an escalating 8-dose regimen. Disclosures:Cartron: Roche: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; GSK: Honoraria. Cazin: LFB Biotechnologies: Honoraria. Coiffier: LFB Biotechnologies: Honoraria. Feugier: roche: Consultancy, Honoraria. Chartier: LFB Biotechnologies: Employment. Sadoun: LFB Biotechnologies: Employment. Ribrag: LFB Biotechnologies: Honoraria, Research Funding.