Invasive fungal infection incidence and risk factors in patients receiving ibrutinib in real-life settings: A nationwide population-based cohort study.

BACKGROUND: Data on the risk of invasive fungal infections (IFI) with ibrutinib treatment are scarce. OBJECTIVES: This study aimed to determine IFI incidence and risk factors in ibrutinib-treated patients in real-life settings. METHODS: We constituted a cohort of ibrutinib incident users in the French National Healthcare Database. All patients ≥18 years with a first dispensing of ibrutinib between 21 November 2014 and 31 December 2019 were included. Patients were followed from the cohort entry date until IFI, ibrutinib discontinuation, death, or 31 December 2020, whichever came first. The cumulative incidence function method was used to estimate the probability of IFI accounting for competing risk of death. A multivariate cause-specific Cox proportional hazards model was used to assess independent IFI risk factors. RESULTS: Among 6937 ibrutinib-treated patients, 1-year IFI cumulative incidence was 1.3%, with invasive aspergillosis being the most frequent. Allogenic or autologous stem cell transplantation (ASCT) (hazard ratio [HR] 3.59, 95% confidence interval [1.74; 7.41]), previous anticancer treatment (HR 2.12, CI 95% [1.34; 3.35]) and chronic respiratory disease (HR 1.66, [1.03; 2.67]) were associated with higher risk of IFI. Besides neutropenia and corticosteroids, use of anti-CD20 agents was significantly more frequent in patients having experienced IFI (HR 3.68, [1.82; 7.45]). CONCLUSIONS: In addition to patients with ASCT history, severe neutropenia or treated with corticosteroids, our findings support active surveillance of IFIs in those with chronic respiratory disease, previously treated, or treated with anti-CD20 agents in combination with ibrutinib. Further studies are needed to optimise IFI prophylaxis in these patient subgroups.

Bleeding risk with concurrent use of anticoagulants and ibrutinib: A population-based nested case-control study.

Data regarding the safety of co-administration of ibrutinib with anticoagulants in real-life settings are scarce. Using a nationwide database, we conducted a nested case-control study in a cohort of new users of ibrutinib to assess the risk of clinically relevant bleeding (CRB) associated with anticoagulation. Cases were patients with a diagnosis of CRB, defined as hospitalization with a diagnosis of bleeding. The date of CRB constituted the index date. Up to four controls were matched on sex, age at index date and duration of follow-up. The risk of CRB associated with anticoagulation in patients receiving ibrutinib was estimated using conditional logistic regression models, providing odds ratios (OR) adjusted for risk factors of bleeding. Among 614 cases and 2407 matched controls, the risk of CRB was significantly higher in patients receiving both ibrutinib and anticoagulants (adjusted OR [aOR] 2.54, confidence interval [CI] 95% [1.94; 3.32]). When considering anticoagulant class, aOR was 1.99 (CI 95% [1.19; 3.33]) for VKA, 2.48 (CI 95% [1.76; 3.47]) for direct oral anticoagulants and 3.40 (CI 95% [2.01; 5.75]) for parenteral anticoagulants. In conclusion, this study found a 2.5-fold increased risk of CRB in patients receiving both ibrutinib and anticoagulants in real-life settings, and similar aOR among oral anticoagulants.

BH3 profiling identifies ruxolitinib as a promising partner for venetoclax to treat T-cell prolymphocytic leukemia.

Conventional therapies for patients with T-cell prolymphocytic leukemia (T-PLL), such as cytotoxic chemotherapy and alemtuzumab, have limited efficacy and considerable toxicity. Several novel agent classes have demonstrated preclinical activity in T-PLL, including inhibitors of the JAK/STAT and T-cell receptor pathways, as well as histone deacetylase (HDAC) inhibitors. Recently, the BCL-2 inhibitor venetoclax also showed some clinical activity in T-PLL. We sought to characterize functional apoptotic dependencies in T-PLL to identify a novel combination therapy in this disease. Twenty-four samples from patients with primary T-PLL were studied by using BH3 profiling, a functional assay to assess the propensity of a cell to undergo apoptosis (priming) and the relative dependence of a cell on different antiapoptotic proteins. Primary T-PLL cells had a relatively low level of priming for apoptosis and predominantly depended on BCL-2 and MCL-1 proteins for survival. Selective pharmacologic inhibition of BCL-2 or MCL-1 induced cell death in primary T-PLL cells. Targeting the JAK/STAT pathway with the JAK1/2 inhibitor ruxolitinib or HDAC with belinostat both independently increased dependence on BCL-2 but not MCL-1, thereby sensitizing T-PLL cells to venetoclax. Based on these results, we treated 2 patients with refractory T-PLL with a combination of venetoclax and ruxolitinib. We observed a deep response in JAK3-mutated T-PLL and a stabilization of the nonmutated disease. Our functional, precision-medicine-based approach identified inhibitors of HDAC and the JAK/STAT pathway as promising combination partners for venetoclax, warranting a clinical exploration of such combinations in T-PLL.

A fixed-duration, measurable residual disease-guided approach in CLL: follow-up data from the phase 2 ICLL-07 FILO trial.

Trials assessing first-line, fixed-duration approaches in chronic lymphocytic leukemia (CLL) are yielding promising activity, but few long-term data are available. We report follow-up data from a phase 2 trial (ICLL07 FILO) in previously untreated, medically fit patients (N = 135). Patients underwent obinutuzumab-ibrutinib induction for 9 months; then, following evaluation (N = 130 evaluable), those in complete remission and with bone marrow measurable residual disease (BM MRD) <0.01% (n = 10) received ibrutinib for 6 additional months; those in partial remission and/or with BM MRD ≥0.01%, the majority (n = 120), also received 4 cycles of immunochemotherapy (fludarabine/cyclophosphamide-obinutuzumab). Beyond end of treatment, responses were assessed every 3 month and peripheral blood MRD every 6 months. At median follow-up 36.7 months from treatment start, progression-free and overall survival rates (95% confidence interval) at 3 years were 95.7% (92.0% to 99.5%) and 98% (95.1% to 100%), respectively. Peripheral blood MRD <0.01% rates were 97%, 96%, 90%, 84%, and 89% at months 16, 22, 28, 34, and 40, respectively. No new treatment-related or serious adverse event occurred beyond end of treatment. Thus, in previously untreated, medically fit patients with CLL, a fixed-duration (15 months), MRD-guided approach achieved high survival rates, a persistent MRD benefit beyond the end of treatment, and low long-term toxicity. This trial was registered at www.clinicaltrials.gov as #NCT02666898.

Advances in Treatment of Waldenström Macroglobulinemia.

PURPOSE OF REVIEW: The discovery of recurring somatic mutations, in particular MYD88 and CXCR4 mutations, in Waldenström macroglobulinemia (WM), a rare B-cell lymphoproliferative disorder, led in the last decade to the development of several therapeutic agents with high efficacy. This review aims to provide an overview of available treatments in WM and novel agents, focusing on studies published over recent years. RECENT FINDINGS: There is no international consensus on the best first-line option in treatment-naïve patients. Randomized clinical trials are rare in WM and there has been no prospective comparison of chemoimmunotherapy and BTK inhibitors in the frontline setting. Chemoimmunotherapy and BTK inhibitors, the two feasible and most widely used treatments in first-line treatment, represent very different options in terms of duration of therapy, route of administration, cost, and adverse effect. In addition to tumor genotype and patient comorbidities, choice of therapy in WM should take into account these parameters. Results of ongoing and future clinical trials evaluating fixed-duration combinations with BTK inhibitors and novel agents are awaited.

Does early disease progression predict survival after first line-treatment of Waldenström macroglobulinemia?

In symptomatic Waldenström macroglobulinemia (sWM) patients, prognosis is assessed with the international prognostic scoring system (IPSSWM). In follicular lymphoma and other B-cell and T-cell lymphomas, disease progression within 24 months (POD24) or (in patients without POD24) after 24 months has been proposed as the start date for stratifying subsequent survival. In the present report, we assessed in a large series of 472 sWM patients, the prognostic value of this new dynamic endpoint already reported in many other lymphomas subtypes. The 3 year subsequent survival for patients with POD24 was 75% and 93% for patients without POD24. In sWM patients, departure from the proportional hazards assumption complicated this analysis. In patients without POD24, the median subsequent progression-free survival time of 43 months accounted for favorable outcome, whereas survival after progression was not influenced by the time to progression. In addition, sensitivity analysis showed that the baseline IPSSWM score also influenced survival after POD24. In sWM patients, we conclude that the apparent difference in survival after POD24 or the 24 months time-point (in patients without POD24) is mainly explained by the prolonged subsequent progression free survival of latter patients. Indeed, the mortality after progression is not influenced by the time to this event.

A prognostic index predicting survival in transformed Waldenström macroglobulinemia.

Histological transformation into diffuse large B-cell lymphoma is a rare complication in patients with Waldenström macroglobulinemia (WM) usually associated with a poor prognosis. The objective of this study was to develop and validate a prognostic index for survival in transformed WM patients. Through this multicenter, international collaborative effort, we developed a scoring system based on data from 133 patients with transformed WM who were evaluated between 1995 and 2016 (training cohort). Univariate and multivariate analyses were used to propose a prognostic index with 2-year survival after transformation as an end-point. For external validation, a data set of 67 patients was used to evaluate the performance of the model (validation cohort). By multivariate analysis, three adverse covariates were identified as independent predictors of 2-year survival after transformation: elevated serum LDH (2 points), platelet count < 100 x 109/L (1 point) and any previous treatment for WM (1 point). Three risk groups were defined: low-risk (0-1 point, 24% of patients), intermediate-risk (2-3 points, 59%, hazard ratio (HR) = 3.4) and high-risk (4 points, 17%, HR = 7.5). Two-year survival rates were 81%, 47%, and 21%, respectively (P < 0.0001). This model appeared to be a better discriminant than the International Prognostic Index (IPI) and the revised IPI (R-IPI). We validated this model in an independent cohort. This easy-to-compute scoring index is a robust tool that may allow identification of groups of transformed WM patients with different outcomes and could be used for improving the development of risk-adapted treatment strategies.

Efficacy of minimal residual disease driven immune-intervention after allogeneic hematopoietic stem cell transplantation for high-risk chronic lymphocytic leukemia: results of a prospective multicenter trial.

Allogeneic hematopoietic stem cell transplantation (HSCT) remains a potentially curative and useful strategy in high-risk relapsing CLL. Minimal Residual Disease (MRD) assessment at 12 months post-HSCT is predictive of relapse. This phase 2 study aimed to achieve M12 MRD negativity (MRDneg) using MRD-driven immune-intervention (Md-PII) algorithm based on serial flow-cytometry blood MRD, involving cyclosporine tapering followed if failure by donor lymphocytes infusions. Patients had high-risk CLL according to 2006 EBMT consensus, in complete or partial response with lymphadenopathy < 5 cm and comorbidity score ≤ 2. Donors were HLA-matched sibling or matched unrelated (10/10). Forty-two enrolled patients with either 17p deletion (front-line, n=11; relapse n=16) or other high-risk relapse (n=15) received reduced intensity-conditioning regimen before HSCT and were submitted to Md-PII. M12-MRDneg status was achieved in 64% versus 14.2% before HSCT. With a median follow-up of 36 months (range, 19-53), 3-year overall survival, non-relapse mortality and cumulative incidence of relapse are 86.9% (95%CI, 70.8-94.4), 9.5% (95%CI, 3.7-23.4) and 29.6% (95%CI, 17.3-47.7). Incidence of 2-year limited and extensive chronic graft versus host disease (cGVHD) is 38% (95%CI, 23-53) and 23% (95%CI, 10-36) including 2 cases post Md-PII. Fifteen patients converted to MRDneg either after CsA withdrawal (n=12) or after cGVHD (n=3). As a time-dependent variable, MRDneg achievement at any time-point correlates with reduced relapse (HR=0.14 [0.04-0.53], p=0.004) and improvement of both progression free (HR=0.18 [0.06-0.6], p<0.005) and overall (HR: 0.18 [0.03-0.98], p=0.047) survival. These data highlight the value of MRD-driven immune-intervention to induce prompt MRD clearance in the therapy of CLL.

Patterns of use and safety of ibrutinib in real-life practice.

AIMS: To provide real-life data on patterns of use and safety of ibrutinib. METHODS: A cohort study including all patients initiating ibrutinib between 21 November 2014 and 21 November 2018, and followed for 1 year was conducted. Patient characteristics, ibrutinib use and adverse drug reactions (ADRs) were collected from medical records. Kaplan-Meier analysis estimated the probability of developing ibrutinib-associated serious ADRs (SADRs) with a 95% confidence interval (CI). A Cox proportional hazards model was used to investigate factors associated with SADR occurrence. RESULTS: In total, 102 patients were included in the study. The median age was 70.3 years (interquartile range 64.7-75.6), the male/female gender ratio was 2.9. Almost half the patients (47.1%) were prescribed ibrutinib for chronic lymphocytic leukaemia (CLL). Forty-three patients (42.1%) permanently discontinued ibrutinib in the first year, mostly for progression (51.2%) or ADRs (32.6%). Forty-eight patients (47.1%) experienced at least one ibrutinib-associated SADR. Haematological, infectious and vascular disorders were the most frequent SADRs. The probability of developing ibrutinib-associated SADR was 35.1% (95% CI 26.3-45.7%) at 3 months, 44.8% (35.2%; 55.8%) at 6 months and 54.3% (44.0%; 65.2%) at 12 months. Age ≥80 years (hazard ratio [HR] 2.03; 95% CI 1.02-4.05) and CLL (HR 1.81; 95% CI 1.01-3.25) were significantly associated with a higher risk of SADR occurrence. CONCLUSION: This study found a high cumulative incidence of ibrutinib-associated SADRs within the first year of treatment. In view of the risk of SADR, patients aged ≥80 years or treated for CLL deserve special attention.

Clinicopathological spectrum of renal parenchymal involvement in B-cell lymphoproliferative disorders.

The clinicopathological characteristics of kidney infiltration in B-cell lymphoproliferative disorders remain poorly described. We retrospectively studied 52 adults with biopsy-proven malignant B-cell kidney infiltration, including Waldenström's macroglobulinemia (n=21), chronic lymphocytic leukemia (n=11), diffuse large B-cell lymphoma (DLBCL) (n=8), other lymphoma (n=11), and multiple myeloma (n=1). Kidney disease varied according to the underlying lymphoproliferative disorder. In DLBCL, malignant kidney infiltration was prominent, resulting in acute kidney injury (AKI, 75%) and kidney enlargement (88%). In the other types, associated immunoglobulin-related nephropathy (most commonly AL amyloidosis) was more common (45%), and chronic kidney disease with proteinuria was the primary presentation. All patients received chemotherapy. Over a median follow-up of 31 months, 20 patients died and 21 reached end-stage kidney disease. Renal response, achieved in 25 patients (48%), was associated with higher overall survival (97 vs. 37 months in non-renal responders). In univariate analysis, percentage of sclerotic glomeruli, kidney enlargement, and complete hematological response at 6 months were predictive of renal response. In multivariate analysis, concomitant immunoglobulin-related nephropathy was the sole independent predictor of poor renal outcome. In conclusion, clinical presentation of renal lymphomatous infiltration depends on the nature of the underlying lymphoproliferative disorder. In DLBCL, massive renal infiltration manifests with enlarged kidneys and AKI, and the diagnosis primarily relies on lymph node biopsy. In other B-cell lymphoproliferative disorders, the clinicopathological spectrum is more heterogeneous, with a high frequency of immunoglobulin-related nephropathy that may affect renal outcome; thus kidney biopsy is required for early diagnosis and prognostic assessment.

Characteristics, outcome, and response to therapy of multirefractory chronic immune thrombocytopenia.

Refractory immune thrombocytopenia (ITP) was previously defined as lack of a minimum response to splenectomy and the requirement for long-term treatment to reduce the risk of significant bleeding events. In this multicenter study, we included 37 patients with multirefractory ITP, defined as no response to splenectomy, rituximab, romiplostim, and eltrombopag. As compared with a historical cohort of 183 ITP patients, matched on the calendar year of ITP diagnosis with a 5:1 ratio, patients with multirefractory ITP were more likely to have secondary ITP (odds ratio [OR], 4.84; 95% confidence interval [CI], 1.31-17.86; P = .018) and monoclonal gammopathy of undetermined significance (OR, 5.94; 95% CI, 1.08-32.48; P = .04). The median duration of ITP before being recognized as multirefractory was 78 months (range, 6-450). The patients showed failure of a median of 10.5 prior treatment lines for ITP (range, 6-15). At the end of follow-up (median, 84 months; range, 12-455), only 1/14 patients achieved response with immunosuppressant therapy alone. By contrast, 7/10 patients achieved response with a combination of immunosuppressant therapy and thrombopoietin-receptor agonists that lasted for a median of 15 months (range, 6-32). Throughout the course of ITP, 5/37 patients died, 3 with ITP (bleeding, n = 2; sepsis n = 1); 15 (40%) had at least 1 bacterial infection and 9 (24%) at least 1 episode of thrombosis. In conclusion, multirefractory ITP was associated with high morbidity and mortality. Combining an immunosuppressant therapy with thrombopoietin-receptor agonists may be a good strategy for management for these patients with severe disease.

Transformed Waldenström macroglobulinaemia: clinical presentation and outcome. A multi-institutional retrospective study of 77 cases from the French Innovative Leukemia Organization (FILO).

Histological transformation (HT) to diffuse large B-cell lymphoma (DLBCL) is a rare and poorly reported complication of Waldenström macroglobulinaemia (WM). We performed a retrospective study of 77 WM patients with biopsy-proven transformation to DLBCL. The median time from WM diagnosis to HT was 4·6 years and 16 patients (21%) had never been treated for WM. At HT, extranodal sites were observed in 91% of patients with a rather high incidence of central nervous system, cutaneous or testicular involvement. Fluorodeoxyglucose-positron emission tomography was performed in half of the patients and the median maximum standardized uptake value was 15 for transformed disease. More than 80% of cases with available data for assessment by the Hans' algorithm harboured a non-germinal centre B-cell phenotype. First-line treatment for transformation consisted of R-CHOP (rituximab, cyclophosphamide, doxorubicin, vincristine, prednisone)-like regimen in 85% of patients. The overall response rate after first-line treatment was 61% and the median overall survival was only 16 months for the entire cohort. Time to transformation above 5 years (P = 0·0004) and elevated LDH (P = 0·02) were associated with worse outcome. Based on these findings, HT should be considered and lead to a biopsy in WM patients presenting with extranodal involvement, elevated LDH and constitutional symptoms. The optimal therapeutic approaches remain to be defined.

Level of RUNX1 activity is critical for leukemic predisposition but not for thrombocytopenia.

To explore how RUNX1 mutations predispose to leukemia, we generated induced pluripotent stem cells (iPSCs) from 2 pedigrees with germline RUNX1 mutations. The first, carrying a missense R174Q mutation, which acts as a dominant-negative mutant, is associated with thrombocytopenia and leukemia, and the second, carrying a monoallelic gene deletion inducing a haploinsufficiency, presents only as thrombocytopenia. Hematopoietic differentiation of these iPSC clones demonstrated profound defects in erythropoiesis and megakaryopoiesis and deregulated expression of RUNX1 targets. iPSC clones from patients with the R174Q mutation specifically generated an increased amount of granulomonocytes, a phenotype reproduced by an 80% RUNX1 knockdown in the H9 human embryonic stem cell line, and a genomic instability. This phenotype, found only with a lower dosage of RUNX1, may account for development of leukemia in patients. Altogether, RUNX1 dosage could explain the differential phenotype according to RUNX1 mutations, with a haploinsufficiency leading to thrombocytopenia alone in a majority of cases whereas a more complete gene deletion predisposes to leukemia.

First-line therapy for chronic lymphocytic leukemia in patients older than 79 years is feasible and achieves good results: A FILO retrospective study.

The mean age at diagnosis of chronic lymphocytic leukemia (CLL) is 72 years, with 22.8% of patients being older than 80 years. However, the elderly are underrepresented in clinical studies of CLL. We performed a retrospective study of CLL patients aged 80 years or older at the initiation of first-line therapy in hospitals affiliated with the French intergroup on CLL (French Innovative Leukemia Organization) between 2003 and 2013. Here, we describe the clinical and biological characteristics, treatment, and outcomes for 201 patients. The median age of the cohort was 83.2 years (80-92 years). The median Cumulative Index Rating Scale comorbidity score was 5 and the median creatinine clearance was 48 mL/min (Cockcroft-Gault formula). At treatment initiation, Binet stage was A (26.4%), B (27.9%), or C (40.3%). Therapy consisted mainly of chlorambucil (65.7%), bendamustine (10.5%), and rituximab (44.3%) as follows: chlorambucil alone (45.3%) or immunochemotherapy (48.3%) with rituximab + chlorambucil (22.7%), rituximab + bendamustine (10.4%), or rituximab + cyclophosphamide + dexamethasone (5.5%). The overall response rate was 66.2% with 31.8% clinical complete remission. The median overall and progression-free survival from treatment initiation was 53.7 and 18.3 months, respectively. These results suggest that treatment is feasible in this age group, even with immunochemotherapy. Thus, prospective trials should target this population and oncogeriatric evaluation and new targeted therapies should be part of such future trials.

Influence of Previous Inflammatory Bowel Disease on the Outcome of Allogeneic Hematopoietic Stem Cell Transplantation: A Matched-Pair Analysis.

The idiopathic inflammatory bowel diseases (IBDs) Crohn's disease and ulcerative colitis are associated with increased risk of hematologic malignancies. Allogeneic hematopoietic stem cell transplantation (HSCT) could be a curative strategy in this setting, but has been thought to be associated with increased nonrelapse mortality (NRM). We conducted a national French retrospective analysis of patients with IBD who underwent allogeneic HSCT for hematologic malignancies and were matched with 3 controls according to recipient, donor, and transplant characteristics. Between 2004 and 2015, 18 patients with IBD underwent allogeneic HSCT. With a median follow-up of 33 months for the patients with IBD and 57 months for controls, the cumulative incidence of grade II-IV acute graft-versus-host disease (GVHD) was 39% for the patients with IBD and 40% for controls (hazard ratio [HR], 1.10; P = .82). The cumulative incidence of chronic GVHD at 48 months was 52% for the patients with IBD and 43% for controls (HR, 0.92; P = .89). Nonrelapse mortality at 48 months was 19% for the patients with IBD and 11% for controls (HR, 4.93; P = .067). Overall survival at 48 months was 59% for the patients with IBD and 60% for matched controls (HR, 1.35; P = .56). In conclusion, IBD should not be considered a contraindication for transplantation, and its impact on comorbidity indexes should be reduced.

Salvage outcomes in patients with first relapse after fludarabine, cyclophosphamide, and rituximab for chronic lymphocytic leukemia: the French intergroup experience.

The optimal management of patients with relapsed chronic lymphocytic leukemia (CLL) is dictated by the type of prior therapy, duration of prior response, presence of genomic aberrations, age, and comorbidities. The patterns of relapses and the clinical outcomes of second-line options after fludarabine-cyclophosphamide-rituximab (FCR) is given as a frontline treatment are currently unknown. In this retrospective and non-randomized study, we report the outcomes of 132 patients from databases of 14 French CLL study group centers who needed a second-line treatment after FCR frontline. Bendamustine + rituximab (BR) was the most frequently used second-line regimen, followed by alemtuzumab-based regimens, R-CHOP, and FCR. Median progression-free survival (PFS) was 18 months after BR with a median overall survival (OS) not reached. We also found that response durations of < 36 months and the presence of del(17p) are critical factors that contribute to poor overall survival. BR appears to be an effective salvage regimen in our series, both in terms of progression-free and overall survival. Patients who relapsed less than 36 months after FCR have a poor outcome, not significantly different in this study from patients with early relapses less than 12 or 24 months.

Long-term follow-up and second malignancies in 487 patients with hairy cell leukaemia.

A large, multicentre, retrospective survey of patients with hairy cell leukaemia (HCL) was conducted in France to determine the frequency of second malignancies and to analyse the long-term effects of the established purine nucleoside analogues (PNAs), cladribine and pentostatin. The survey retrospectively reviewed the medical history of patients and their immediate family, clinical and biological presentation at the time of HCL diagnosis, treatment choice, response to treatment, time to relapse and cause of death. Data were collected for 487 patients with HCL. Of the patients included in the survey, 18% (88/487) had a familial history of cancers, 8% (41/487) presented with malignancies before HCL diagnosis and 10% (48/487) developed second malignancies after HCL was diagnosed. An excess incidence of second malignancies was observed, with a standardized incidence ratio (SIR) of 1·86 (95% confidence interval (CI): 1·34-2·51), with no significant difference between PNAs. For second haematological malignancies alone, the SIR was markedly increased at 5·32 (95% CI: 2·90-8·92). This study highlights the high frequency of cancers in HCL patients and their family members. The frequency of second malignancies is notably increased, particularly for haematological malignancies. The respective role of pentostatin and cladribine in the development of second malignancies is debatable.