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Polycythemia vera (PV) is a myeloproliferative disorder, characterized by the expansion of the red cell mass. Our purpose was to evaluate the efficacy of pipobroman (PB) in the long-term control of PV and to assess early and late events.From June 1975 to December 1997, 163 untreated patients with PV (median age 57 years, range 30-82) were treated with PB in a single Institute for a median follow-up of 120 months. The diagnosis was made according to the Polycythemia Vera Study Group criteria. PB was given at the dose of 1 mg/kg/day until hematologic response (hematocrit45% and platelets400x109/L) and of 0.3-0.6 mg/kg/day as maintenance therapy.Hematologic remission was achieved in 94% of patients in a median time of 13 weeks (range 6-48). Median overall survival was 215 months, with a standardized mortality ratio of 1.7. The cumulative risk of death was 11%, 22%, and 26% at 7, 10, and 12 years, respectively. The incidence of thrombotic events was 18.4x105 person-year and the cumulative risk was 6%, 11%, 16%, and 20% at 3, 7, 10, and 12 years respectively. Acute leukemia occurred in 11 patients, myelofibrosis in 7, and solid tumors in 11. The 10-year cumulative risk of leukemia, myelofibrosis, and solid tumors was 5%, 4%, and 8%, respectively. In the logistic analysis age over 65 (p = 0.0001) and thrombotic events at diagnosis (p = 0.001) were significantly correlated with a higher risk of death. Female gender (p = 0.02) and age over 65 (p = 0.01) significantly influenced the occurrence of thrombotic complications. Age was the only significant risk factor for leukemia (p = 0.04) and for solid tumors (p = 0.03), while the duration of PB treatment did not influence these risks. No significant risk factor was demonstrated for myelofibrosis.This study demonstrates in a large series of patients, observed for a long period, that pipobroman is effective in the long-term control of PV. The risk of early thrombotic complications at 3 years is 6% and the 10-year risk of acute leukemia, late myelofibrosis, and solid tumors is 5%, 4%, and 8%, respectively. The duration of pipobroman treatment did not correlate with these events.

Introduction: In patients with primary immune thrombocytopenia (ITP), a short course of steroids is routinely given as first-line therapy. However, the response is often transient and additional therapy is usually needed. Thrombopoietin receptor agonists (TPO-RAs) are frequently used as second-line therapy, although there is little clinical guidance on the timing of their administration and on tapering/discontinuation of the drug. To provide clinical recommendations, we used the Delphi technique to obtain consensus for statements regarding administration and on tapering/discontinuation of second-line TPO-RAs among a group of Italian clinicians with expertise in management of ITP. Methods: The Delphi process was used to obtain agreement on five statements regarding initiation and on tapering/discontinuation of second-line TPO-RAs. Agreement was considered when 75% of participants approved the statement. Eleven experts participated in the voting. Results: Full consensus was reached for three of the five statements. The experts held that an early switch from corticosteroids to a TPO-RA has the dual advantage of sparing patients from corticosteroid abuse and improve long-term clinical outcomes. All felt that dose reduction of TPO-RAs can be considered in patients with a stable response and platelet count >100 × 109/L that is maintained for at least 6 months in the absence of concomitant treatments, although there was less agreement in patients with a platelet count >50 × 109/L. Near consensus was reached regarding the statement that early treatment with a TPO-RA is associated with an increase in clinically significant partial or complete response. The experts also agreed that optimization of tapering and discontinuation of TPO-RA therapy in selected patients can improve the quality of life. Conclusion: The present consensus can help to provide guidance on use of TPO-RAs in daily practice in patients with ITP. Plain language summary Second-line administration of thrombopoietin receptor agonists in immune thrombocytopenia There is little guidance on the timing of administration and tapering/discontinuation of thrombopoietin receptor agonists (TPO-RAs) in patients with primary immune thrombocytopenia (ITP). The Delphi technique was used to obtain consensus for five statements. The present consensus among Italian clinicians aims to provide guidance on second-line use of TPO-RAs for patients with ITP in daily practice.

Thrombopoietin receptor agonists (TPO-RAs) are currently indicated for continuous treatment of chronic primary immune thrombocytopenia (ITP). However, there is growing evidence that TPO-RAs can also trigger sustained response in 10-30% of cases after treatment tapering and discontinuation. Therefore, at least for selected responding patients, it might be rational to plan TPO-RA interruption to exploit off-treatment response. Intriguingly, complete or partial responses with TPO-RAs are frequently observed when treatments are initiated early, suggesting that unknown immune-related mechanisms may be involved in this phenomenon. The sustained responses observed after interruption of TPO-RAs may be interpreted as a recovery of immunological tolerance; thus, the re-establishment of immunological equilibrium might be primarily responsible for the observed off-treatment effect. Importantly, these findings may indicate that anticipated TPO-RA usage can lead to improved responses, and that optimized tapering and interruption in selected patients can furthermore improve prognoses. On the base of this rationale, a series of real-life considerations have been generated by a panel of Experts to elucidate possible novel criteria and modalities to identify subgroups of patients who can benefit from tapering and/or discontinuation of TPO-RAs. Towards this aim, the results of a survey of ITP experts are herein reported, reflecting a snapshot of current real-life experience on early discontinuation of TPO-RA-based therapy. The present manuscript also highlights the importance of future translational studies on novel prognostic and predictive biomarkers that can stratify patients and facilitate the clinical choice for second-line treatment of ITP.

Background: The question of which parameters may be informative on venetoclax outcome in chronic lymphocytic leukemia (CLL) is still unclear. Furthermore, the choice to treat with venetoclax can be challenging in patients with baseline characteristics or comorbidities that may potentially favor some specific adverse events. Objectives: This study was aimed to evaluate whether age, fitness status, patients’/disease characteristics, or concomitant medications may predict outcomes in CLL patients receiving venetoclax. Design: Retrospective observational study. Methods: Impact of age, presence of Cumulative Illness Rating Scale (CIRS) >6 or severe organ impairment (CIRS3+), Eastern Cooperative Oncology Group–Performance Status (ECOG-PS), renal function, and concomitant medications were retrospectively analyzed on treatment management (definitive discontinuation due to toxicity, discontinuation due to toxicity, Tox-DTD; permanent dose reduction, PDR) and survival [progression free survival (PFS), event free survival (EFS), overall survival (OS)] in unselected patients receiving venetoclax monotherapy in common practice. Results: A total of 221 relapsed/refractory patients were included. Tox-DTD and PDR were reported in 5.9% and 21.7%, respectively, and were not influenced by any fitness parameter, age, number or type of concomitant medication, baseline neutropenia, or impaired renal function. None of these factors were associated with tumor lysis syndrome (TLS) development. Age and coexisting conditions had no influence on PFS and EFS. At univariate analysis, OS was significantly shorter only in patients with ECOG-PS >1 ( p 6 ( p = 0.014) or CIRS3+ ( p = 0.031). ECOG-PS >1 retained an independent role only for EFS and OS. While Tox-DTD affected all survival outcomes, no differences in PFS were reported among patients permanently reducing dose or interrupting venetoclax for > 7 days. Conclusion: Clinical outcome with venetoclax is not influenced by comorbidities, patients’ clinical characteristics, or concomitant medications. Differently from other targeted therapies, this demonstrates that, except ECOG-PS, none of the parameters generally considered for treatment choice, including baseline neutropenia or impaired renal function, should rule the decision process with this agent. Anyway, if clinically needed, a correct drug management does not compromise treatment efficacy and may avoid toxicity-driven discontinuations. Plain Language Summary Chapter 1: Why was this study done? Chapter 2: Which are the main findings of the study? Chapter 3: How these findings may impact on clinical practice? Coexisting conditions and concomitant medications do not affect venetoclax management and survival in chronic lymphocytic leukemia • The question of which parameters may be informative on venetoclax outcome in chronic lymphocytic leukemia is still unclear. Furthermore, the choice to treat with venetoclax can be challenging in patients with baseline characteristics or comorbidities that may potentially favor some specific adverse events (e.g. compromised renal function or baseline neutropenia). • In our large series of patients treated outside of clinical trials, we demonstrated that neither age, fitness, comorbidities nor concomitant medications impact on venetoclax management and survival. Importantly, patients presenting with baseline neutropenia or impaired renal function did not have a higher rate of dose reductions or toxicity-driven discontinuations, thus further underlining that venetoclax may be safely administered even in those categories with no preclusions. • Differently from other targeted agents, our data demonstrate that none of the baseline factors commonly considered in treatment decision process retains a role with venetoclax. Finally, permanent dose reductions and temporary interruptions did not adversely impact PFS suggesting that, if clinically needed, a correct drug management should be adopted with no risk of compromising venetoclax efficacy.

Key points Age per se does not influence outcome in CLL patients on ibrutinib, whereas CIRS score is predictive of treatment management, PFS, and EFS.ECOG-PS and neutropenia resulted as the only baseline parameters affecting overall survival., Visual Abstract, Functional reserve of organs and systems is known to be relevant in predicting immunochemotherapy tolerance. Age and comorbidities, assessed by the cumulative illness rating scale (CIRS), have been used to address chemotherapy intensity. In the ibrutinib era, it is still unclear whether age, CIRS, and Eastern Cooperative Oncology Group performance status (ECOG-PS) retain their predictive role on treatment vulnerability. In this series of 712 patients with chronic lymphocytic leukemia (CLL) treated with ibrutinib outside clinical trials, baseline ECOG-PS and neutropenia resulted as the most accurate predictors of treatment feasibility and outcomes. Age did not independently influence survival and ibrutinib tolerance, indicating that not age per se, but age-related conditions, may affect drug management. We confirmed the role of CIRS > 6 as a predictor of a poorer progression- and event-free survival (PFS, EFS). The presence of a severe comorbidity was significantly associated with permanent dose reductions (PDRs), not translating into worse outcomes. As expected, del(17p) and/or TP53mut and previous therapies affected PFS, EFS, and overall survival. No study so far has analyzed the influence of concomitant medications and CYP3A inhibitors with ibrutinib. In our series, these factors had no impact, although CYP3A4 inhibitors use correlated with Cox regression analysis, with an increased risk of PDR. Despite the limitation of its retrospective nature, this large study confirmed the role of ECOG-PS as the most accurate predictor of ibrutinib feasibility and outcomes, and importantly, neutropenia emerged as a relevant tool influencing patients’ vulnerability. Although CIRS > 6 retained a significant impact on PFS and EFS, its value should be confirmed by prospective studies.

Recommendations for dyslipidemia management aimed at reducing arterial occlusive events (AOEs) have been recently published. So far, no data have been reported on the management of dyslipidemia in chronic myeloid leukemia (CML) patients treated with nilotinib. We investigated 369 CML adult patients, stratified according to the new Systematic Coronary Risk Evaluation (SCORE) scoring system. Plasma levels of cholesterol, HDL, LDL, and triglycerides were measured prior to the start of nilotinib and after 3, 6, and 12months. The 5-year cumulative incidence of AOEs was 15.9%. Patients with cholesterol levels > 200mg/dL and LDL > 70mg/dL 3months after treatment showed a significantly higher incidence of AOEs (21.9 ± 4.6% vs 6.2 ± 2.5, P= 0.003). Patients belonging to the high and very high SCORE risk group showed a significant increase of AOEs (34.4 ± 6% vs 10 ± 2.1%, P< 0.001). In multivariate analysis, both high cholesterol and LDL levels and a high and very high SCORE risk remained significantly associated with the risk of AOEs (P= 0.008; HR = 3.5; 95% CI = 1.4–8.7 and P < 0.001; HR = 4.4; 95% CI = 2–9.8, respectively). Overall, 78 patients (21.1%) presented dyslipidemia at the time of CML diagnosis and 88 (23.3%) after starting nilotinib, but only 26 of them (29.5%) were treated with statins. Low LDL and cholesterol plasma levels are associated with a significant lower risk of AOEs in CML patients treated with nilotinib in the real life.

Hypertension is a commonly reported comorbidity in patients diagnosed with chronic myeloid leukemia (CML), and its management represents a challenge in patients treated with 2nd- or 3rd-generation tyrosine kinase inhibitors (TKIs), considering their additional cardiovascular (CV) toxicity. The renin angiotensin system (RAS) contributes to hypertension genesis and plays an important role in atherosclerosis development, proliferation, and differentiation of myeloid hematopoietic cells. We analyzed a cohort of 192 patients with hypertension at CML diagnosis, who were treated with 2nd- or 3rd-generation TKIs, and evaluated the efficacy of RAS inhibitors (angiotensin-converting enzyme inhibitors (ACEi) and angiotensin-II receptor blockers (ARBs)) in the prevention of arterial occlusive events (AOEs), as compared with other drug classes. The 5-year cumulative incidence of AOEs was 32.7 ± 4.2%. Patients with SCORE ≥ 5% (high-very-high) showed a significantly higher incidence of AOEs (33.7 ± 7.6% vs 13.6 ± 4.8%, p = 0.006). The AOE incidence was significantly lower in patients treated with RAS inhibitors (14.8 ± 4.2% vs 44 ± 1%, p < 0.001, HR = 0.283). The difference in the low and intermediate Sokal risk group was confirmed but not in the high-risk group, where a lower RAS expression has been reported. Our data suggest that RAS inhibitors may represent an optimal treatment in patients with hypertension and CML, treated with 2nd or 3rdG TKIs.

In chronic myeloid leukemia (CML) patients, tyrosine kinase inhibitors (TKIs) may select for drug-resistant BCR-ABL1 kinase domain (KD) mutants. Although Sanger sequencing (SS) is considered the gold standard for BCR-ABL1 KD mutation screening, next-generation sequencing (NGS) has recently been assessed in retrospective studies. We conducted a prospective, multicenter study (NEXT-in-CML) to assess the frequency and clinical relevance of low-level mutations and the feasibility, cost, and turnaround times of NGS-based BCR-ABL1 mutation screening in a routine setting. A series of 236 consecutive CML patients with failure (n = 124) or warning (n = 112) response to TKI therapy were analyzed in parallel by SS and NGS in 1 of 4 reference laboratories. Fifty-one patients (22 failure, 29 warning) who were negative for mutations by SS had low-level mutations detectable by NGS. Moreover, 29 (27 failure, 2 warning) of 60 patients who were positive for mutations by SS showed additional low-level mutations. Thus, mutations undetectable by SS were identified in 80 out of 236 patients (34%), of whom 42 (18% of the total) had low-level mutations somehow relevant for clinical decision making. Prospective monitoring of mutation kinetics demonstrated that TKI-resistant low-level mutations are invariably selected if the patients are not switched to another TKI or if they are switched to a inappropriate TKI or TKI dose. The NEXT-in-CML study provides for the first time robust demonstration of the clinical relevance of low-level mutations, supporting the incorporation of NGS-based BCR-ABL1 KD mutation screening results in the clinical decision algorithms.

No abstract available.

Not available.

Background Limited information is available regarding the rate of long-term cardiovascular (CV) mortality in chronic myeloid leukaemia (CML) patients treated with second- and third-generation tyrosine kinase inhibitors (2ndG/3rdG TKIs) in the real-life practice. Methods We identified 656 consecutive CML patients treated with nilotinib, dasatinib, bosutinib and ponatinib. Results The 15-year CV-mortality free survival was 93 ± 2.8%. Age ≥65 years (p = 0.005) and a positive history of CV disease (p = 0.04) were significantly associated with a lower CV-mortality free survival. CV disease accounted for 16.5% and 5% of potential years of life lost (PYLL) in male and female patients, respectively. The standard mortality ratio (SMR) following ischemic heart disease (IHD) was 3.9 in males and 3.8 in female patients, meaning an excess of IHD deaths observed, in comparison with the population of control. Conclusion. Prevention strategies based on CV risk factors, in particular in those patients with a previous history of CV disease, should be considered.

Background Risk of death is particularly high in patients with a previous history of arterial occlusive events (AOEs) and the probability for a recurrent event is around 20%. Little is known about recurrent AOE and the role of secondary prevention in patients with Chronic Myeloid Leukemia (CML) with previous AOE, treated with second- and third-generation tyrosine kinase inhibitors (2ndG/3rdG TKIs), nilotinib, dasatinib, bosutinib and ponatinib. Methods We identified a real-life cohort of 57 consecutive adult CML patients treated with 2ndG/3rdG TKI. All patients had a previous history of AOE. Ongoing use of secondary prevention of AOE (including antiplatelet agents, anticoagulant therapy, and statins) before starting a 2ndG/3rdG TKI was recorded, as well as CV risk factors. Results The 60-month cumulative incidence rate of recurrent AOEs was 47.8 ± 10.9%. Despite a history of AOE, 10 patients (16%) were not receiving secondary preventative measures. Patients treated with nilotinib and ponatinib showed a higher incidence of recurrent AOEs (76.7 ± 14.3% and 64 ± 20.1%, respectively) than those treated with dasatinib and bosutinib (44 ± 24.2% and 30.5 ± 15.5%, respectively) (p = 0.01). Only treatment with a 2ndG/3rdG TKI given as second or subsequent line therapy showed a significant association with an increased incidence of recurrent AOE (p = 0.039). Overall, 17 recurrent AOEs were observed; 3 CV-related deaths were reported. Conclusion CML patients with a previous history of AOE treated with 2ndG/3rdG TKI represent a particular patient population with a higher probability of experiencing a recurrent AOE; individualized treatment is needed to optimize secondary prevention.

Arterial occlusive events (AOEs) represent emerging complications in chronic myeloid leukemia (CML) patients treated with ponatinib. We identified 85 consecutive CML adult patients who were treated with ponatinib in 17 Italian centers. Patients were stratified according to the Systematic Coronary Risk Evaluation (SCORE) assessment, based on sex, age, smoking habits, systolic blood pressure, and total cholesterol levels. The 60-month cumulative incidence rate of AOEs excluding hypertension was 25.7%. Hypertension was reported in 14.1% of patients. The median time of exposure to ponatinib was 28months (range, 3-69months). Patients with a high to very high SCORE risk showed a significantly higher incidence rate of AOEs (74.3% vs 15.2%, P&nbsp

Introduction Fludarabine, cyclophosphamide and rituximab (FCR) and bendmaustine rituximab (BR) combinations have both been evaluated as salvage regimens in Waldenstrom's Macroglobulinemia. FCR exerts good quality of responses but there are some concerns regarding its use mainly for tardive myelosuppression and long term toxicity. BR showed to be effective with an excellent short term toxic profile but in literature there are no data on long term follow-up and toxicity. The aim of this study was to evaluate long term outcome and long term toxicity of patients treated with FCR and BR. Patients and Methods We analyzed 87 relapsed and refractory Waldenstrom's Macroglobuklinemia patients enrolled in two retrospective Italian multicenter studies in which FCR or BR were administered as salvage regimens. Patients treated with both bendamustine and fludarabine were excluded from the study. For each treatment group we compared: clinical and disease characteristics, Progression free survival (PFS) defined as progression or death for any cause from the beginning of salvage treatment; Event free survival (EFS) defined as progression or development of major infection, solid tumor, secondary MDS/AML, DLBCL, or death due to any cause. Results Of the 87 patients, 37 had received FCR and 50 BR. The two groups of patients did not differ in sex, median age, median number of prior treatments, previous therapy with alkylating agents, disease status, median IgM level, presence of adenopathies and/or splenomegaly at CT performed before salvage treatment. The significant differences between the two groups were: higher number of patients >70 years in the BR group (P=0.01) and lower number of patients previously treated with monoclonal antibody in the FCR population (P Conclusions FCR and BR as salvage regimens led to similar outcome in terms of PFS and EFS. Considering that FCR in respect to BR exerts long lasting responses the main issue remains its long term toxicity profile. The future challenge will be to assess the long term effect of the new targeted agents. Disclosures Ferrero: Mundipharma: Other: Speakers Honoraria; Celgene: Other: Speakers Honoraria.

Objective High dose (HD) Ara-C combined with a single HD idarubicin dose (IDA) is an efficient and safe salvage regimen for patients with refractory or relapsed acute lymphoblastic leukemia as indicated by phase II studies. No data are available on the pharmacokinetics of IDA after a rapid HD intravenous infusion. An open phase II pharmacokinetic and clinical study was performed to evaluate antileukemic efficacy, IDA pharmacokinetics and to investigate the presence of IDA and its reduced metabolite idarubicinol (IDAol) in cerebrospinal fluid (CSF) of patients treated with HD-IDA. Patients and methods Twenty-five patients with refractory or relapsed acute lymphoblastic leukemia received Ara-C 3 g/m2 from days 1–5, idarubicin (HD-IDA) 40 mg/m2 as rapid intravenous (i.v.) infusion on day 3 and subcutaneous G-CSF 5 μg/kg from day 7 until PMN recovery. Pharmacokinetics of IDA was evaluated after HD idarubicin administration in nine of these patients. CSF samples were collected in 15 patients at different times. IDA and IDAol concentrations were quantified by a validated HPLC assay described in detail elsewhere. Results Eleven patients (44%, 95% CI: 23–65%) achieved complete remission with median disease free survival for 6 months. After administration of HD-IDA i.v. bolus of 40 mg/m2, plasma level profiles of unchanged drug and IDAol were similar to those previously described after standard dose and measured with the same analytical method. The mean terminal half-life measured for IDA in this group of patients (14.9 h) was not significantly different from the mean value observed after standard dose (13.9 h, P = 0.72). IDAol t 1/2 was also similar after HD-IDA (46.2 h) and standard dose (39.4 h, P = 0.79). Pharmacokinetic data reveal that in our series of patients IDA and IDAol clearances are significantly higher than those observed in patients treated with 12 mg/m2 of IDA but, although the administered dose (mg/m2) of the drug is 3.3 times higher, IDA exposure (measured in terms of AUC) is only 2.3 times and IDAol exposition 2.1 times greater. Furthermore, HD infusion resulted in a ratio between the AUC of parent drug and idarubicinol not different from the value observed with the standard-dose. IDA and IDAol were measurable only in 3 of the 15 cerebrospinal fluid samples collected. Conclusion Responses observed in our series are comparable to those reported with other salvage regimens. The IDA exposure lower than expected may explain the safety of the single i.v. administration of 40 mg/m2 of IDA, combined with HD Ara-C, with a degree of myelosuppression equivalent to that reported with this agent administered in standard doses. Our data do not allow us to clearly attribute this behavior to a pharmacokinetic non-linearity since the baseline creatinine clearance, even within normal values, and patient age are significantly different in the two groups. Cerebrospinal fluid penetration was poor, reaching levels not considered as cytotoxic.

Background. Pegfilgrastim is a polyethylene glycol (PEG)-conjugated form of G-CSF in which filgrastim is bound covalently to a 20kDa PEG molecule; this formulation increases serum half-life of G-CSF due to decreased renal elimination. Following the subcutaneous injection of a 6 mg single dose of pegfilgrastim, serum levels of G-CSF are maintained over a period of 2 weeks. In patients with lymphoma, pegfilgrastim is as effective as filgrastim in shortening the time of neutropenia after cytotoxic chemotherapy; however, the ability of pegfilgrastim to mobilize stem cells after chemotherapy is poorly understood and the optimal mobilization strategy remains controversial. Aims. We evaluate the efficacy of a single fixed 6 mg dose of pegfilgrastim after salvage therapy with cisplatin-containing chemotherapy regimens in mobilizing peripheral blood stem cells in aggressive lymphoma patients. Moreover the possibility of a sufficient collection of CD34+ PBSC (cell dose > 2,5 x106/Kg) in a single procedure was tested. Methods. Between July 2004 and July 2005 twenty two pretreated patients with aggressive lymphoma (8 Hodgkin’s lymphoma, 11 diffuse large B cell lymphoma, 3 anaplastic lymphoma) received salvage chemotherapy with cisplatin-based regimens: (R)-DHAP, dexametasone, cisplatin, cytarabine, or (R)-IPAD idarubicin, dexametasone, cisplatin, cytarabine, with or without Rituximab. A 6 mg single dose of pegfilgrastim was given from day +1 or +2 after chemotherapy completion. Duration of grade 4 neutropenia, adverse events, time to neutrophil and CD34+ cell recovery were recorded. Stem cell collection was started when the absolute number of CD34+ was not less than 20/μL. Leukapheresis was daily performed until the minimum target cell dose of 2.5 x 10 6 CD34+ cells /kg was reached. Results. Following the administration of either (R)-DHAP or (R)-IPAD regimens, 21/ 22 pts (95%) were able to harvest a median of 14,2 x 10 6/Kg CD34+ cell (range 2,4– 45,8), after a median of 9 days from stimulation (range 8–12). A single apheresis procedure was sufficient to obtain a median of 14,8 x 10 6/kg CD34+ cell (range 5,2–45,8) in 18/21 pts (86%) Grade 4 neutropenia was present in all pts with a median duration of 3 days (range 1–7). Pegfilgrastim determined mild bone pain as only adverse event. Seven patients underwent autologous bone marrow transplantation and all of them showed a rapid and sustained engraftment after high-dose chemotherapy. Conclusions. In aggressive lymphoma patients a single dose of pegfilgrastim following chemotherapy completion was safe and highly effective in enhancing the mobilization of CD34+ PBSC. Stem cell collection was performed in a single procedure in most of patients (86%) obtaining a stem cell harvest of a median of 14,8 x 106/Kg CD34+ cells. In 7 autologous bone marrow transplanted patients these results determined early engraftment and sustained hematological reconstitution.