Unselected donor-derived hematopoietic stem cells boost for Chimeric Antigen Receptor T-cell associated hematotoxicity.

Hematological toxicity following Chimeric Antigen Receptor-T therapy in a patient with a prior allogeneic stem cell transplantation was resolved by the infusion of unselected donor-derived stem cell boost. Due to the donor's lymphocytes, the patient experienced a well-controlled flare-up of acute graft versus host disease.

Genetic mutations and leukapheresis in acute myeloid leukemia: is there a link?

Acute myeloid leukemia is the most common acute leukemia in adults and up to 20% of patients present with hyperleukocytosis at the onset of the disease. The therapeutic approach involves medical support, cytoreductive treatment, and/or leukapheresis. Despite WBC count greater than 100.000/µL, not all patients develop symptoms. To clarify the role of leukapheresis in the setting of hyperleukocytotic AML, we aimed to find associations between AML morphologic subtypes and molecular alterations on presence or absence of leukostasis symptoms (and hence therapeutic vs prophylactic leukapheresis) and clinical outcomes in the cohort of 41 patients at our single center who underwent leukapheresis for hyperleukocytotic AML. There was a trend for increased WBC count, 30-day mortality, M4-M5 AML subtypes, and number of leukapheresis procedures performed in symptomatic hyperleukocytotic pts. No molecular marker was significantly associated with presence or absence of leukostasis symptoms due to small sample size, though there was a trend for increased NPM1-mutated and NPM1 + FLT3-mutated AML in asymptomatic patients and a greater proportion of symptomatic patients who were negative for all assessed molecular alterations. In conclusion, leukapheresis combined with cytoreductive treatment represents a synergic and efficient approach in the management of hyperleukocytosis especially in symptomatic patients considering the higher mortality independently from the presence of specific clonal markers whose distribution among the two groups may result more considerable with a higher number of patients.

Successful stem cell collection for atypical teratoid rhabdoid tumor in an extremely low-body weight child: A case report.

The use of peripheral blood hematopoietic stem cells for bone marrow reconstitution after myeloablative therapy is well established in children with malignant disorders. However, the peripheral blood hematopoietic stem cells collection in very low-body weight (≤10 kg) children remains a significant challenge because of technical and clinical issues. A male newborn affected by atypical teratoid rhabdoid tumor, diagnosed prenatally, received two cycles of chemotherapy following surgical resection. After an interdisciplinary discussion, it was decided to intensify the treatment with high-dose chemotherapy followed by autologous stem cell transplantation. After 7 days of G-CSF administration the patient underwent hematopoietic progenitor cells-apheresis collection. The procedure was performed in the pediatric intensive care unit, using two central venous catheters and Spectra Optia device. The cell collection procedure was completed in 200 min, during which time 3.9 total blood volumes were processed. During apheresis we did not observe electrolyte alterations. No adverse events were recorded during or immediately following the cell collection procedure. Our report describes the feasibility of performing large volume leukapheresis without complications in an extremely low-body weight patient weighing 4.5 kg using the Spectra Optia apheresis device. No catheter-related problems occurred, and apheresis was completed without any adverse event. In conclusion, we believe that very low-body weight pediatric patients need a multidisciplinary approach to manage central venous access, hemodynamic monitoring, cell collection, prevention of metabolic complications to improve safety, feasibility, and efficiency of stem cell collection procedures.

Successful "on-demand" plerixafor for autologous peripheral blood stem-cells transplantation for relapsed/refractory germ cell tumors.

BACKGROUND: Germ cell tumors represent, among solid cancers, a potentially curable disease even if up to 20% to 30% of patients (pts) relapse after first-line treatment especially considering intermediate and poor prognosis groups. In this scenario, patients are candidates for high-dose chemotherapy and autologous stem-cells transplantation as second-line treatment even though stem-cells mobilization potential can be affected by several cycles and regimens of chemotherapy. To date, plerixafor is authorized in poor mobilizer adult pts diagnosed with lymphoma or multiple myeloma and in pediatric solid tumors or lymphoma. Therefore, the use of plerixafor in adult pts with relapsing/refractory GCT is still off label. MATERIALS AND METHODS: In our study, we describe mobilization and collection of peripheral blood stem cells for 10 pts with germ cell tumors. Six patients underwent plerixafor administration since classified as poor mobilizers based on WBC count (>5.000/µL) and CD34+ cell count (<15/µL) the day before apheresis procedure. RESULTS: On the first day of apheresis, plerixafor administration in poor mobilizers made possible a remarkable boost of CD34+ cells in such a way to overlap that of good mobilizers' (32/µL vs 35/µL, respectively, P > .05). CONCLUSION: Therefore, in our experience, plerixafor made a good fraction of poor mobilizer patients eligible for mobilization and collection and able to undergo the predicted autologous stem-cells transplantation; thus, the lack of access to the use of plerixafor in this setting of patients risks jeopardizing an effective treatment, especially in case of poor prognosis.

Inline and offline extracorporeal photopheresis: Device performance, cell yields and clinical response.

BACKGROUND: Extracorporeal photopheresis (ECP) is an effective treatment for graft-vs-host-disease (GvHD). Photopheresis can be performed in offline or inline method. The first uses a conventional cell separator for collection of mononuclear-cells that are photoactivated by a separate device and manually reinfused; the second one involves a dedicated device performing the entire procedure (collection, photoactivation and reinfusion). STUDY DESIGN AND METHODS: The objective was to compare the two methods and cell product features to highlight key process, devices performance, and to evaluate ECP clinical response. Patients developing steroid-resistant GvHD underwent ECP as second-line treatment using either inline (Therakos CellEx) or offline system (Terumo BCT Spectra or Optia and UVA PIT system). Data about patients' features, pre-apheresis blood-count, cell product characteristics and clinical response were collected for analysis. RESULTS: We evaluated 494 procedures performed on 28 patients from April 2018 to March 2019. The offline procedure allows to achieve greater cell yield, it is characterized by larger processed blood volume, longer runtime, and higher ACD consumption. The inline procedure shows shorter runtime, high mononuclear-cells percentage and low percentage of granulocytes in cell product. We observed a significant difference in cell yields between inline and offline system; furthermore we did not find a significant relationship between cell dose and clinical response. CONCLUSION: Inline ECP is fast, highly automated and productive, making it particularly suitable for ECP treatments. Offline ECP collects high cell yields implying longer procedure and greater operator intervention. Our study did not find a significant relationship between cell dose and GVHD response.

Peripheral Blood Hemopoietic Stem Cell Mobilization Regimens in POEMS Syndrome: A Retrospective Study at 2 Hematologic Italian Centers.

Autologous peripheral blood stem cell transplantation should be considered first-line therapy in young patients with POEMS. The best protocol to collect peripheral blood stem cells remains to be defined, because of the disease rarity and the heterogeneity of published case series. We collected clinical and laboratory data from 25 patients undergoing mobilization, of whom 11 were mobilized using cyclophosphamide (CY) followed by granulocyte colony-stimulating factor (G-CSF) and 14 patients using G-CSF. The incidence of poor mobilization was low and not statistically different between the 2 groups. Both schemes (CY plus G-CSF versus G-CSF alone) were able to harvest a sufficient CD34+ cell dose.

Inline extracorporeal photopheresis: evaluation of cell collection efficiency.

BACKGROUND: Extracorporeal photopheresis (ECP) therapy has proved to be an effective and safe treatment for graft-versus-host-disease (GvHD), an important complication after hematopoietic stem cell transplantation. In 2016, we acquired Therakos CellEx, a dedicated inline ECP device to accomplish a significant increase in ECP activity. In literature, we found few data reporting CellEx performance evaluated in terms of collection efficiency to qualify the device. Hence, we decided to collect and analyze our data in order to build a reference in terms of expected results of the procedure. Here we report our data of ECP performed using CellEx in a 12-month period focusing on collection efficiency assessment, as well as procedural and apheretic product characteristics. STUDY DESIGN AND METHODS: We collected data of patients undergoing ECP from April 2018 to March 2019 using CellEx in order to evaluate collection efficiency. RESULTS: Between April 2018 and March 2019 we treated 28 adult patients affected by GvHD performing 319 ECP using CellEx. CellEx mononuclear cell product was characterized by high mononuclear cell percentage and low percentage of granulocytes, resulting particularly suitable for ECP treatments. Median collection efficiency for total nucleated cells and for mononuclear cells was 31.2% and 62.3%, respectively. CONCLUSION: Collection efficiency of CellEx was comparable to that usually obtained by cell separators designed for cell collection and was comparable to that of offline systems. Our results provide a detailed performance evaluation for inline ECP system users.

Autologous peripheral blood stem cell transplantation and the role of lenalidomide in patients affected by poems syndrome.

POEMS syndrome is a rare paraneoplastic condition, with a poorly understood pathogenesis. High dose chemotherapy followed by autologous stem cell transplantation (ASCT) has been reported to be an effective therapeutic option for patients with good performance status. Here, we review the role of ASCT for POEMS syndrome and discuss indications together with advantages and disadvantages, and related issues such lenalidomide given before or after ASCT, VEGF levels as a marker of disease, and different regimens for stem cell mobilization.

Mononuclear cell collection for extracorporeal photopheresis: Concentrate characteristics for off-line UV-A irradiation procedure.

BACKGROUND AND OBJECTIVE: Extracorporeal photopheresis (ECP) is the most represented cell therapy for treatment of cutaneous T-cell lymphoma, graft-versus host disease and organ rejection. We analyzed our experience in ECP using 2 cell separators (Cobe Spectra and Spectra Optia) focusing on leukapheretic product characteristics, UV-A irradiation procedure and entire ECP process. MATERIALS AND METHODS: We collected data of patients undergoing ECP between January 2012 and February 2015 in order to evaluate collection procedures performed using Cobe Spectra and Spectra Optia, mononuclear cell product, UV-A photoirradiation procedure by Pit System. RESULTS: We performed 484 ECP procedures in 27 patients. Cobe-derived mononuclear cell products were characterized by higher cell yields while Optia-derived mononuclear cell products were characterized by smaller volume, comparable mononuclear cell content but lower erythrocytes, granulocytes, and platelets contamination. CONCLUSION: Our study confirms good results for both cell separators. Blood volume processed being equal, Cobe collects a number of total nucleated cells significantly higher than Optia. Optia, collecting only target cells without significant erythrocytes, granulocytes and platelets contamination, is able to collect a leukapheretic product particularly suitable for ECP.

Changes in protein serum levels during stem cell transplantation.

BACKGROUND: GvHD is one of the major complication after stem cell transplantation affecting transplant-related mortality. Throughout the last years, many serum proteins were been proposed as possible biomarkers for GvHD. AIMS: We studied the trend of five of the most studied serum proteins to evaluate whether a correlation exists between proteins concentration and post-HSCT outcomes. MATERIALS AND METHODS: We measured serum concentration of REG3α, ST2, B-cell activating factor (BAFF), CXCL9 and elafin in a cohort of 77 patients submitted to Hematopoietic allogeneic stem cell transplantation (HSCT) in our department. Blood samples were been collected at baseline, day +30, GvHD onset and GvHD resolution. RESULTS: REG3α levels showed an association only with acute GvHD. Elafin and ST2 levels varied according to both acute and chronic GvHD occurrence. BAFF concentration showed an inverse association with acute GvHD development. Interestingly, baseline BAFF and ST2 levels predicted post-HSCT survival. No associations were found for CXCL9. CONCLUSIONS: Except for CXCL9, the protein levels seem to change according to GvHD development, independently from organ involvement and grading. Pretransplant ST2 and BAFF appeared to be predictors for survival after HSCT.

The role of molecular typing and perfect match transfusion in sickle cell disease and thalassaemia: An innovative transfusion strategy.

Chronic red blood cell transfusions remain an essential part of supportive treatment in patients with thalassaemia and sickle cell disease (SCD). Red blood cell (RBC) transfusions expose patients to the risk of developing antibodies: RBC alloimmunization occurs when the immune system meets foreign antigens. We created a register of extensively genotyped donors to achieve a better matched transfusion in order to reduce transfusion alloimmunization. Extended RBC antigen typing was determined and confirmed by molecular biology techniques using Human Erythrocyte Antigen (HEA) BeadChip (BioArray Solutions Ltd., Warren, NJ) in periodic blood donors and in patients with thalassaemia and SCD. During 3 years, we typed extensively 1220 periodic blood donors, 898 male and 322 female. We also studied 10 hematologic patients affected by thalassaemia and sickle cell disease referred to our institution as candidate to periodic transfusions. Our patients (8 females and 2 males with a median age of 48 years, range 24-76 years), extensively typed using molecular techniques and screened for RBC alloantibodies, were transfused with a median of 33.5 RBC units. After three years of molecular typing, the "perfect match" transfusion strategy avoided new alloantibodies development in all studied patients.

Weak D Type 4.2.2 (DAR1.2) in an African child: Serology and molecular characterization.

The weak D phenotype is represented by a group of RHD genotypes that code for alterated RhD proteins associated with a reduced RhD expression on red blood cell. By routine serology, some partial D variants are likely to be missed. In this report we describe the case of a three-year-old Black African child with a "unclear" reaction with monoclonal anti-D. We analyzed the blood sample of the child with different methods to conclude that it is a case of DAR 1.2 (weak D 4.2.2) and that it must be transfused with D negative erithrocytes.

Day -1 CD34+ Cells and Platelet Count Predict the Number of Apheresis in Poor-Mobilizer Patients Rescued by Plerixafor.

Plerixafor is widely used as up-front treatment with G-CSF to enhance peripheral blood hematopoietic stem cell output in patients failing previous mobilizations. Less frequently, plerixafor is used to rescue an unsatisfactory mobilization following chemotherapy (CT) and G-CSF. This study investigates if pre-collection factors affect the CD34+ cell harvest in chemotherapy and G-CSF mobilizations rescued by plerixafor. Clinical and hematological data relative to patients, mobilization, and apheresis products were retrospectively examined. The outcome was completing a target cell dose ≥ 2 × 106 CD34+ cells/kg at first apheresis. The effect exerted on the outcome by patient- and disease-related factors was investigated by univariate and multivariate logistic regression analysis. The analysis included data from 42 patients affected by hematological (39 patients) and non-hematological malignancies (three patients). Twenty-nine patients (69%) attained the target cell dose at first apheresis. Twelve out of the remaining 13 patients received an additional plerixafor administration, and all accomplished the transplant dose at a second apheresis procedure. Day -1 CD34+ PB count (OR1.46, 95% CI 1.1-1.9, p = 0.008) and platelet count (OR1.0, 95% CI 1.0-1.0, p = 0.033) predicted the achievement of the target dose at first apheresis, independently of pre-mobilization CT, radiation therapy, and disease status at mobilization. At ROC curve analysis, the best cut-off value predicting the successful collection at first apheresis was 7.5/µL for Day -1 CD34+ cell count (AUC 0.830, 0.69 sensitivity, and 0.92 specificity) and 75 × 109/L for Day -1 platelet count (AUC = 0.736, 0.65 sensitivity and 0.85 specificity). In conclusion, on-demand plerixafor rescue allows a successful stem cell collection, irrespectively of disease type and status, prior CT lines, and radiation exposure. Pre-apheresis CD34+ cells and platelet count predict the need for one or two aphereses.

Midline catheters for extracorporeal photopheresis in hematological patients.

INTRODUCTION: Peripheral venous access for extracorporeal photopheresis (ECP) may be difficult in graft versus host disease (GVHD) patients, because of previous intravenous therapies and multiple peripheral cannulations; in this population of patients, ultrasound guided midline catheters may be an alternative option to central venous access. METHODS: In this single-center, prospective preliminary study, we enrolled all consecutive patients with a diagnosis of GVHD and candidate to ECP, over a period of 10 months. We used inserted power injectable, non-valved, polyurethane, 20-25 cm single lumen midline catheters (MC). RESULTS: Sixty-nine ECP procedures were carried out in six patients, using single-lumen MCs for outflow (5Fr in 74% and 4Fr in 26% of cases). For inflow, we used 5Fr or 4Fr MCs, or central venous access devices previously placed for other clinical reasons. There were no catheter-related complications during the entire period of ECP treatment. Mean outflow was significantly higher for 5Fr than for 4Fr MCs (35.8 ± 7.3 vs 29.2 ± 7.8 ml/min; p = 0.0008) and the procedure time was significantly shorter (92.9 ± 9.2 vs 108 ± 13.2 min; p < 0.0001). CONCLUSION: In GVHD patients, ECP can be performed efficiently and safely using single lumen polyurethane power injectable MCs. The best results are obtained with 5Fr rather than with 4Fr catheters. This strategy of venous access should be implemented in DIVA patients requiring ECP treatments, and probably also in other types of apheresis.

Peripheral Blood Allogeneic Stem Cell Mobilization: Can We Predict a Suboptimal Mobilization?

Allogeneic peripheral blood stem cells mobilization is now the basis of most stem cell transplants. In a very limited number of cases, mobilization is suboptimal leading to further collection procedures, to suboptimal cell doses infusion with delayed engraftment time, increased risks of transplant procedure and of related costs. To date we have no recognized and shared criteria for early estimating the probability of poor mobilization in healthy donors. We then analyzed allogeneic peripheral blood stem cell donations performed at the Fondazione Policlinico Universitario A.Gemelli IRCCS Hospital from January 2013 to December 2021 in order to identify premobilization factors associated with successful mobilization. The following data were collected: age, gender, weight, complete blood cell count at baseline, G-CSF dose, number of collection procedures, CD34+ cell count in peripheral blood on the first day of collection, CD34+ cell dose per kg body weight of recipient. Mobilization efficacy was defined according to the number of CD34+ cells in peripheral blood on day +5 of G-CSF administration. We classified donors as sub-optimal mobilizers or good mobilizers according to the achievement of the 50 CD34+ cell/µL threshold. We observed 30 suboptimal mobilizations in 158 allogeneic peripheral blood stem cell donations. Age and baseline white blood cell count were factors significantly associated with negative or positive impact on mobilization, respectively. We did not find significant differences in mobilization based on gender or G-CSF dose. Using cut-off values of 43 years and 5.5×109/L WBC count, we built a suboptimal mobilization score: donors who reach 2, 1 or 0 points have a 46%, 16% or 4% probability of suboptimal mobilization, respectively. Our model explains 26% of the variability of mobilization confirming that most of the mobilization magnitude depends on genetically determined factors; however, suboptimal mobilization score is a simple tool providing an early assessment of mobilization efficacy before G-CSF administration begins in order to support allogeneic stem cells selection, mobilization and collection. Through a systematic review, we looked for confirmation of our findings. According to the published articles, all the variables we included in our model are confirmed to be strongly related to the success of mobilization. We believe that score system approach could be applied in clinical practice to assess the risk of mobilization failure at baseline allowing for a priori intervention.

Managing leukapheresis in adult and pediatric patients eligible for chimeric antigen receptor T-cell therapy: suggestions from an Italian Expert Panel.

Chimeric antigen receptor (CAR) T-cell therapy relies on T cells engineered to target specific tumor antigens such as CD-19 in B-cell malignancies. In this setting, the commercially available products have offered a potential long-term cure for both pediatric and adult patients. Yet manufacturing CAR T cells is a cumbersome, multistep process, the success of which strictly depends on the characteristics of the starting material, i.e., lymphocyte collection yield and composition. These, in turn, might be affected by patient factors such as age, performance status, comorbidities, and previous therapies. Ideally, CAR T-cell therapies are a one-off treatment; therefore, optimization and the possible standardization of the leukapheresis procedure is critical, also in view of the novel CAR T cells currently under investigation for hematological malignancies and solid tumors. The most recent Best Practice recommendations for the management of children and adults undergoing CAR T-cell therapy provide a comprehensive guide to their use. However, their application in local practice is not straightforward and some grey areas remain. An Italian Expert Panel of apheresis specialists and hematologists from the centers authorized to administer CAR T-cell therapy took part in a detailed discussion on the following: 1) pre-apheresis patient evaluation; 2) management of the leukapheresis procedure, also in special situations represented by low lymphocyte count, peripheral blastosis, pediatric population <25 kg, and the COVID-19 outbreak; and 3) release and cryopreservation of the apheresis unit. This article presents some of the important challenges that must be faced to optimize the leukapheresis procedure and offers suggestions as to how to improve it, some of which are specific to the Italian setting.

Poor mobilizer: a retrospective study on proven and predicted incidence according to GITMO criteria.

The Italian Group for Bone Marrow Transplantation (Gruppo Italiano Trapianto di Midollo Osseo, GITMO) recently formalized criteria for a shared definition of poor mobilizer in order to facilitate randomized clinical trials and study comparison focusing on the efficacy of current mobilizing regimens. The availability of a standardized tool for poor mobilizer definition suggested us to retrospectively test GITMO criteria feasibility and applicability. Therefore we analyzed medical and laboratory records of adult patients affected by myeloma (MM) or lymphoma undergoing mobilization for autologous peripheral blood HSC collection from January 2010 to June 2011, at Servizio di Emotrasfusione, Istituto di Ematologia, Università Cattolica Del Sacro Cuore, Roma, UOC SIMT AO S. Camillo Forlanini Roma and SIMT Fondazione Policlinico Tor Vergata Roma. We collected data about 227 patients (134 male, 93 female) affected by MM (31.3%) NHL (58.6%) e HD (10.1%). Thirty-nine patients, 21 male and 18 female met proven poor mobilizer criteria definition resulting in a incidence of 17.2% (12.7% in MM, 21.8% in NHL and 4.3% in HD). Eleven patients, seven affected by lymphoma and four affected by myeloma, were defined predicted PM according to major criteria. Eight patients, seven affected by lymphoma and one affected by myeloma, were define predicted PM according to minor criteria. Sixteen out of 39 patients defined as poor mobilizer either according to major or minor criteria underwent collection procedures and eight (20.5%) achieved a cell dose ⩾2×10(6)/kg CD34(+) cells. GITMO criteria application was easy and resulted in poor mobilizer incidence comparable to current literature. Definitions of proven poor mobilizer and predicted poor mobilizer according to major criteria were very effective while minor criteria were less predictive. These results came from a retrospective analysis and therefore should be validated in future prospective trial. On the other hand these data could be an early overall view of the foreseeable future of peripheral blood stem cell collection. In conclusion we believe that these criteria will be able to better characterize poor mobilizer phenomenon and, consequently, to identify patients taking advantage from new mobilizing agents.

Day +60 WT1 assessment on CD34 selected bone marrow better predicts relapse and mortality after allogeneic stem cell transplantation in acute myeloid leukemia patients.

The aim of this study was to evaluate the role of WT1 expression after allogeneic stem cell transplantation (alloHSCT) in patients with acute myeloid leukemia (AML). We studied WT1 expression in bone marrow cells from 50 patients in complete remission on day +60 after transplant. WT1 was assessed on unfractionated bone marrow mononuclear cells (MNC) and on CD34+ selected cells (CD34+). A ROC curve analysis identified 800 WT1 copies on CD34+ selected cells, as the best cut-off predicting relapse (AUC 0.842, p=0.0006, 85.7% sensitivity and 81.6% specificity) and 100 copies in MNC (AUC 0.819, p=0.007, 83.3% sensitivity and 88.2% specificity). Using the 800 WT1 copy cut off in CD34+ cells, the 2 year cumulative incidence of relapse was 12% vs 38% (p=0.005), and 2 year survival 88% vs 55% (p=0.02). Using the 100 WT1 copy cut off in unfractionated MNC, the 2 year cumulative incidence of relapse 13% vs 44% (p=0.01) and the 2 year survival 88% vs 55% (p=0.08). In a multivariate Cox analysis WT1 expression in CD34 cells proved to highly predictive of relapse (p=0.004); also WT1 expression on unfractionated cells predicted relapse (p=0.03). In conclusion, day-60 WT1 expression after allogeneic HSCT is a significant predictor of relapse, particularly when tested on CD34+ selected bone marrow cells.

Comparison between oral and intravenous fludarabine plus cyclophosphamide regime as front-line therapy in patients affected by chronic lymphocytic leukaemia: influence of biological parameters on the clinical outcome.

The fludarabine plus cyclophosphamide (FC) regimen was reported to be superior to chlorambucil or fludarabine alone in terms of complete response (CR), overall response (OR) and progression-free survival (PFS) in previously untreated patients with chronic lymphocytic leukaemia (CLL). In the present study, we compared the efficacy and toxicity of FC administered through oral and intravenous route in 65 untreated patients affected by advanced CLL. No statistical differences were noticed between the two routes of administration in terms of OR, PFS, time to re-treatment (TTR) and overall survival (OS) of analysed patients. We also assessed the influence on the clinical outcome of the mutation status of the immunoglobulin variable region heavy chain (IgVH) gene, of the cytogenetic abnormalities and of the expression of ZAP70 and CD38 in patients' primary samples. Among the 58 evaluable patients, 31 (53%) achieved a CR and 18 (31%) a partial response. The median PFS was 35 months, median TTR was 42 months and median OS was not reached after 45 months (range, 1-161). A significantly lower OR rate was noticed in patients with high-risk cytogenetic abnormalities (del 17p, del 11q). In this study, high-risk cytogenetic abnormalities and unmutated IgVH genes were independent predictors of TTR. These results underline the importance of biological stratifications in front-line treatment of CLL patients. We confirm that FC is an effective regimen with mild toxicities; it could be recommended for patients with low-risk biological parameters who represent, in our experience, about 30% of the total.