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Unlabelled: A phase I-II study of bendamustine fractionated twice daily schedule for 4 days identified 75 mg/m(2) intravenously(IV) twice daily for 4 days as a phase II study schedule., Background: Alkylating agents have shown activity in leukemia. Bendamustine, an active alkylating agent in lymphoma and chronic lymphocytic leukemia, was given in a fractionated twice daily schedule for 4 days to patients with acute leukemia and myelodysplastic syndrome (MDS) to define the dose-limiting toxicities (DLT) and maximum tolerated dose (MTD)., Patients and Methods: Adults with refractory acute leukemia or high-risk MDS were treated with bendamustine at a starting dose of 50 mg/m(2) IV over 1-2 hours twice daily for 4 days. Dose escalations were by 25 mg/m(2) in the 1st 3 levels. The study used the 3 + 3 design., Results: A total of 25 patients were treated. Their median age was 57 years; the median salvage number was 3. Grade 2 creatinine elevations were observed in 1 of 6 patients at the 50 mg/m(2) dose, in 2 of 13 patients at the 75 mg/m(2) dose, and in 3 of 6 patients at the 100 mg/m(2) dose. This was considered significant, even though DLT was not reached. One patient achieved marrow complete remission. Significant reductions of marrow blasts (50% or more) were observed in 6 of 25 patients (24%)., Conclusion: Bendamustine fractionated dose level of 100 mg/m(2) IV twice daily for 4 days (800 mg/m(2) per course) was associated with Grade 2 renal toxicity. The proposed phase II schedule is 75 mg/m(2) IV twice daily for 4 days. Future studies should evaluate this schedule in less heavily treated patients., (Copyright © 2012 Elsevier Inc. All rights reserved.)

MGCD0103 is an isotype-selective inhibitor of histone deacetylases (HDACs) targeted to isoforms 1, 2, 3, and 11. In a phase 1 study in patients with leukemia or myelodysplastic syndromes (MDS), MGCD0103 was administered orally 3 times weekly without interruption. Twenty-nine patients with a median age of 62 years (range, 32-84 years) were enrolled at planned dose levels (20, 40, and 80 mg/m(2)). The majority of patients (76%) had acute myelogenous leukemia (AML). In all, 24 (83%) of 29 patients had received 1 or more prior chemotherapies (range, 0-5), and 18 (62%) of 29 patients had abnormal cytogenetics. The maximum tolerated dose was determined to be 60 mg/m(2), with dose-limiting toxicities (DLTs) of fatigue, nausea, vomiting, and diarrhea observed at higher doses. Three patients achieved a complete bone marrow response (blasts

In this study, we investigated the mechanism of apoptosis induction of obatoclax (GX15-070), a novel Bcl-2 homology domain-3 (BH3) mimetic, in acute myeloid leukemia (AML) cell lines and primary AML samples. Obatoclax inhibited cell growth of HL-60, U937, OCI-AML3, and KG-1 cell lines. Apoptosis induction contributed to the observed antiproliferative effects at concentrations of this agent that mirror its affinity for antiapoptotic Bcl-2 proteins. We show that obatoclax can promote the release of cytochrome c from isolated leukemia cell mitochondria and that apoptosis induced by this agent is preceded by the release of Bak from Mcl-1, liberation of Bim from both Bcl-2 and Mcl-1, and the formation of an active Bak/Bax complex. Notably, apoptosis was diminished, but not fully prevented, in the absence of Bak/Bax or Bim, suggesting that obatoclax has additional targets that contribute to its cytotoxicity. At growth inhibitory doses that did not induce apoptosis or decrease viability, obatoclax induced an S-G(2) cell-cycle block. Obatoclax induced apoptosis in AML CD34+ progenitor cells with an average IC(50) of 3.59 +/- 1.23 micromol/L although clonogenicity was inhibited at concentrations of 75 to 100 nmol/L. Obatoclax synergized with the novel BH3 mimetic ABT-737 to induce apoptosis in OCI-AML3 cells and synergistically induced apoptosis in combination with AraC in leukemic cell lines and in primary AML samples. In conclusion, we show that obatoclax potently induces apoptosis and decreases leukemia cell proliferation and may be used in a novel therapeutic strategy for AML alone and in combination with other targeted agents and chemotherapeutics.

Biphenotypic acute leukaemia (BAL) is a rare type of leukaemia. Whether patients with BAL should be treated with regimens designed for acute myeloid leukaemia (AML), acute lymphocytic leukaemia (ALL) or both remain unclear. We have reviewed the clinical data for 31 BAL patients. Most patients co-expressed B-lymphoid and myeloid markers. No specific chromosomal abnormality was identified. The majority of the patients were treated with regimens devised for treating ALL. Seven patients were treated with regimens designed for AML. Complete remission (CR) rates of 78% and 57% were noted respectively. The overall survival probability at 2 years was 60%.

We conducted a phase 1/2 study of the combination of 5-aza-2'-deoxycytidine (decitabine) and the histone deacetylase inhibitor valproic acid (VPA) in patients with advanced leukemia, including older untreated patients. A group of 54 patients were treated with a fixed dose of decitabine (15 mg/m(2) by IV daily for 10 days) administered concomitantly with escalating doses of VPA orally for 10 days. A 50 mg/kg daily dose of VPA was found to be safe. Twelve (22%) patients had objective response, including 10 (19%) complete remissions (CRs), and 2 (3%) CRs with incomplete platelet recovery (CRp). Among 10 elderly patients with acute myelogenous leukemia or myelodysplastic syndrome, 5 (50%) had a response (4CRs, 1CRp's). Induction mortality was observed in 1 (2%) patient. Major cytogenetic response was documented in 6 of 8 responders. Remission duration was 7.2 months (range, 1.3-12.6+ months). Overall survival was 15.3 months (range, 4.6-20.2+ months) in responders. Transient DNA hypomethylation and global histone H3 and H4 acetylation were induced, and were associated with p15 reactivation. Patients with lower pretreatment levels of p15 methylation had a significantly higher response rate. In summary, this combination of epigenetic therapy in leukemia was safe and active, and was associated with transient reversal of aberrant epigenetic marks.

Triptolide, a diterpenoid isolated from the Chinese herb Tripterygium wilfordii Hook.f, has shown antitumor activities in a broad range of solid tumors. Here, we examined its effects on leukemic cells and found that, at 100 nM or less, it potently induced apoptosis in various leukemic cell lines and primary acute myeloid leukemia (AML) blasts. We then attempted to identify its mechanisms of action. Triptolide induced caspase-dependent cell death accompanied by a significant decrease in XIAP levels. Forced XIAP overexpression attenuated triptolide-induced cell death. Triptolide also decreased Mcl-1 but not Bcl-2 and Bcl-X(L) levels. Bcl-2 overexpression suppressed triptolide-induced apoptosis. Further, triptolide induced loss of the mitochondrial membrane potential and cytochrome C release. Caspase-9 knock-out cells were resistant, while caspase-8-deficient cells were sensitive to triptolide, suggesting criticality of the mitochondrial but not the death receptor pathway for triptolide-induced apoptosis. Triptolide also enhanced cell death induced by other anticancer agents. Collectively, our results demonstrate that triptolide decreases XIAP and potently induces caspase-dependent apoptosis in leukemic cells mediated through the mitochondrial pathway at low nanomolar concentrations. The potent antileukemic activity of triptolide in vitro warrants further investigation of this compound for the treatment of leukemias and other malignancies.

Leukemias have traditionally been classified and treated on the basis of phenotypic characteristics, such as morphology and cell-surface markers, and, more recently, cytogenetic aberrations. These classification systems are flawed because they do not take into account cellular function. The leukemia cell population is functionally heterogeneous: it consists of leukemia stem cells (LSC) and mature leukemia cells that differentiate abnormally to varying extents. Like normal hematopoietic stem cells, LSCs are quiescent and have self-renewal and clonogenic capacity. Because they are quiescent, LSCs do not respond to cell cycle-specific cytotoxic agents used to treat leukemia and so contribute to treatment failure. These cells may undergo mutations and epigenetic changes, further leading to drug resistance and relapse. Recent data suggest that mature leukemia cells may acquire LSC characteristics, thereby evading chemotherapeutic treatment and sustaining the disease. Ongoing research is likely to reveal the molecular mechanisms responsible for LSC characteristics and lead to novel strategies for eradicating leukemia.

Clofarabine (2-chloro-2'-fluoro-deoxy-9-beta-D-arabinofuranosyladenine) is a second-generation nucleoside analog with activity in acute leukemias. As clofarabine is a potent inhibitor of ribonucleotide reductase (RnR), we hypothesized that clofarabine will modulate ara-c triphosphate accumulation and increase the antileukemic activity of cytarabine (ara-C). We conducted a phase 1-2 study of clofarabine plus ara-C in 32 patients with relapsed acute leukemia (25 acute myeloid leukemia [AML], 2 acute lymphoblastic leukemia [ALL]), 4 high-risk myelodysplastic syndrome (MDS), and 1 blast-phase chronic myeloid leukemia (CML).(1) Clofarabine was given as a 1-hour intravenous infusion for 5 days (days 2 through 6) followed 4 hours later by ara-C at 1 g/m(2) per day as a 2-hour intravenous infusion for 5 days (days 1 through 5). The phase 2 dose of clofarabine was 40 mg/m(2) per day for 5 days. Among all patients, 7 (22%) achieved complete remission (CR), and 5 (16%) achieved CR with incomplete platelet recovery (CRp), for an overall response rate of 38%. No responses occurred in 3 patients with ALL and CML. One patient (3%) died during induction. Adverse events were mainly less than or equal to grade 2, including transient liver test abnormalities, nausea/vomiting, diarrhea, skin rashes, mucositis, and palmoplantar erythrodysesthesias. Plasma clofarabine levels generated clofarabine triphosphate accumulation, which resulted in an increase in ara-CTP in the leukemic blasts. The combination of clofarabine with ara-C is safe and active. Cellular pharmacology data support the biochemical modulation strategy.

Clonal expansion of leukemic cells is thought to be due to proliferation in excess of apoptosis. To define and compare proliferation and apoptosis between various leukemias and myelodysplastic syndrome (MDS), we measured proliferating cell nuclear antigen (PCNA) and bromodeoxyuridine (BrdU) incorporation as surrogate markers for proliferation and caspase 3 activity and annexin V surface binding as surrogate markers for activation of the apoptotic cascade in patients with MDS, chronic myelomonocytic leukemia (CMML), acute myeloid leukemia (AML), acute lymphoblastic leukemia (ALL), chronic lymphocytic leukemia (CLL), and chronic myeloid leukemia (CML). We found high proliferation in bone marrow cells from MDS and CMML as measured by PCNA and BrdU incorporation. The lowest level of proliferation was found in CLL. Apoptosis was also highest in MDS and CMML as measured by annexin V and caspase 3 activity. Unexpectedly, we found no significant difference in proliferation in bone marrow CD34+ cells from various leukemias or MDS. Apoptosis was significantly higher in bone marrow CD34+ cells from MDS and CML in chronic phase as compared to CD34+ cells from AML patients. Our results illustrate differences in proliferation and apoptosis between acute and chronic leukemias and MDS. These differences may have diagnostic and therapeutic implications.

BACKGROUND: Nilotinib is a potent, second-generation inhibitor of BCR-ABL1 tyrosine kinase and has been approved as frontline and salvage therapy for patients with chronic-phase chronic myeloid leukemia (CP-CML). METHODS: In this single-institution, phase 2 study, 122 patients with newly diagnosed CP-CML received nilotinib 400 mg twice daily. The median follow-up on study was 78.3 months (interquartile range, 58.4-96.5 months). RESULTS: Fifty-six percent of patients remained on therapy at the last follow-up. Both the complete cytogenetic response rate and the major molecular response (MR) rate were 91%. Seventy-five percent and 59% of patients achieved a ≥4.5-log reduction in BCR-ABL1 transcripts (MR4.5) and a sustained MR4.5 beyond 2 years, respectively. The estimated event-free survival and overall survival rates at 5 years were 89% and 93%, respectively, and the corresponding rates at 10 years were 85% and 88%, respectively. Treatment discontinuation due to toxicity occurred in 19% of patients, mostly because of cardiovascular events (10%) and biochemical abnormalities (6%). The top 3 nonhematologic toxicities were rash (55%), elevated bilirubin (57%), and elevated aminotransferases (48%). Hematologic toxicity was transient and mild. Ischemic cardiovascular adverse events occurred in 8% of patients. Four patients (3%) progressed to accelerated or blast phase while on therapy, and 7 patients (6%) died on study. CONCLUSIONS: The current data confirm the long-term efficacy of nilotinib 400 mg twice daily in patients with CP-CML. A majority of patients can achieve sustained MR4.5.

This phase 2 study was conducted to prospectively evaluate how clinical and biological factors correlate with outcome in patients with treatment-naive (TN) and relapsed (R) chronic lymphocytic leukemia (CLL) treated with lenalidomide and rituximab. Oral lenalidomide 10 mg was administered daily starting on day 9 of cycle 1. IV rituximab 375 mg/m2 was administered weekly during cycle 1 and every 4 weeks for cycles 3 to 12. Sequencing of a custom panel of 295 genes was performed in pretreatment bone marrow samples. The study included 61 patients with TN CLL and 59 with R CLL; the overall response rate (ORR) was 73% and 64%, respectively. A baseline β2-microglobulin level 2 previous therapies (P = .02) was the only factor associated with shorter PFS in R patients. A trend for association between mutations in the NOTCH pathway and shorter PFS was observed in TN CLL (P = .15). Further exploration of the NOTCH pathway may help optimize the efficacy of this combination in patients with CLL. This study protocol was approved by the University of Texas MD Anderson Cancer Center institutional review board and registered at clinicaltrials.gov (#NCT01446133).

Cardiovascular or arteriothrombotic adverse events (CV- or AT-AEs) are reported in chronic myeloid leukemia (CML) patients treated with tyrosine kinase inhibitors (TKIs). The incidence and characteristics across different TKI have not been systematically analyzed. We analyzed 531 patients treated with frontline TKIs in different prospective trials: imatinib 400 mg (n = 71) and 800 mg (n = 203), nilotinib (n = 108), dasatinib (n = 106), and ponatinib (n = 43). Characteristics and incidence of new-onset CV-AEs and AT-AEs were analyzed. Poisson regression models assessed factors associated with AE incidence. Median follow-up was 94 months (range, 2-195). Overall, 237 patients (45%) developed CV-AEs and 46 (9%) developed AT-AEs. Hypertension was the most common AE seen in 175 patients (33%; grade 3/4 in 17%). CV-AE and AT-AE incidence ratios (IRs) with 95% confidence intervals (CIs) were 8.6 (7.6-9.8) and 1.7 (1.2-2.2) per 100 person-years. Among the TKIs, ponatinib showed the highest IR (95% CI) for CV-AEs and AT-AEs at 40.7 (27.9-59.4) and 9.0 (4.1-20.1). In multivariate analysis, ponatinib therapy was associated with increased incidence rate ratio (IRR) for CV-AEs (4.62; 95% CI, 2.7-7.7; P < .0001) and AT-AEs (6.38; 95% CI, 1.8-21.8; P < .0001) compared with imatinib 400. In summary, there is an increased risk of CV-AEs (except hypertension) and AT-AEs in CML patients treated with newer TKIs, particularly with ponatinib. Patients on TKIs must be informed and closely monitored for vascular AEs. These studies were registered at www.clinicaltrials.gov as #NCT00048672, #NCT00038649, #NCT00050531, #NCT00254423, #NCT00129740, and #NCT01570868.

BackgroundTreatment with tyrosine kinase inhibitors (TKIs) for patients with chronic myeloid leukemia (CML) is effective but needs to continue for several years, possibly indefinitely. Although generally safe, TKI may have hitherto poorly recognized effects in the quality of life (QoL) of such patients.MethodsWe prospectively measured the symptom burden of patients with chronic phase CML enrolled on frontline TKI trials with dasatinib, nilotinib, or ponatinib. A total of 219 patients were enrolled and filled out the MD Anderson Symptom Inventory (MDASI)-CML questionnaire before the start of therapy and during follow-up at defined time points of 3, 6, 9, 12, 18, and 24 months.ResultsThe median age was 50 years. Longitudinal analysis showed relatively stable symptom severity scores over time. Fatigue was the most common symptom in all three cohorts, both prior to the start of therapy and during therapy, including after achievement of deep molecular remission. Work was the most affected component of daily living. Overall patients tolerated therapy well with improvement of their symptoms from baseline, with few dose reductions related to toxicity or symptomatology. Although 31% of the patients who completed MDASI-CML achieved complete molecular remission by 24 months of treatment, nearly 90% experienced persistent mild symptoms.ConclusionSide effects related to TKIs may impact the quality of life in patients with CML-CP. Further studies should investigate factors (comorbidities, concomitant medications, dose and schedule, etc) associated with these symptoms and interventions that may improve the patients' QoL, including treatment discontinuation when safely feasible.

Achieving undetectable MRD (U-MRD) status after chemoimmunotherapy predicts longer progression-free and overall survival. The predictive factors and timing of relapse in patients with U-MRD and value of interim MRD analysis are ill-defined. This was a prospective study of 289 patients with CLL treated first-line with FCR. MRD analysis was performed after course 3 (C3) and at end of therapy (EOT) in bone marrow using 4-color flow cytometry (sensitivity 10-4). Eighteen percent of patients had U-MRD after C3 and 48% at EOT. U-MRD status at EOT was associated with longer PFS (median NR vs 38 mo, p 1%) after C3 predicted greater likelihood of U-MRD status at EOT (64% vs 9%, p 1% after C3 (median 73 mo vs 41 mo, p

BACKGROUND:Front-line therapy for elderly or unfit patients with acute myeloid leukaemia (AML) remains unsatisfactory with poor outcomes and excessive toxicity. We studied a new low-intensity regimen of cladribine combined with low-dose cytarabine alternating with decitabine, aimed at improving outcomes in this population. Based on our previous experience, we hypothesised that this combination would be safe and more effective than current approaches with hypomethylating agents. METHODS:In this single-arm, open-label, single-centre phase 2 study, we enrolled patients aged 60 years or older with previously untreated AML or high-risk myelodysplastic syndrome who had adequate organ function and an Eastern Cooperative Oncology Group performance status of 2 or less. Patients were treated with cladribine plus low-dose cytarabine for two 28-day cycles alternating with decitabine for two 28-day cycles, for up to 18 cycles. Induction therapy (cycle 1) consisted of cladribine 5 mg/m2 intravenously over 1-2 h on days 1-5 and cytarabine 20 mg subcutaneously twice daily on days 1-10. Patients who had remission during this induction regimen moved on to consolidation therapy (cladribine 5 mg/m2 intravenously over 1-2 h on days 1-3 and cytarabine 20 mg twice daily on days 1-10, alternating with decitabine 20 mg/m2 intravenously on days 1-5). The primary outcome measure was disease-free survival. Secondary outcomes were overall survival, proportion of patients achieving complete response, proportion of patients achieving response, toxicity, and induction mortality. All treated patients were included in the analyses. This trial is ongoing and is registered with ClinicalTrials.gov, number NCT01515527. FINDINGS:Between Feb 17, 2012, and July 6, 2017, 118 patients were enrolled and treated, among whom 48 (41%) had an adverse karyotype, 20 (17%) had therapy-related AML, 18 (15%) had treated secondary AML, and 20 (17%) had TP53 mutations. Median disease-free survival was 10·8 months (IQR 5·4-25·9). 80 (68%) patients achieved objective response: 69 (58%) achieved a complete response and 11 (9%) patients had complete response with incomplete count recovery. The median overall survival was 13·8 months (6·9-28·6). The regimen was well tolerated, with one (1%) death within the first 4 weeks and eight (7%) deaths within the first 8 weeks. The most common non-haematological adverse events of grade 3 or worse were infection (88 [75%] patients), elevated total bilirubin (26 [22%] patients), rash (13 [11%] patients), and nausea (13 [11%] patients). INTERPRETATION:The combination of cladribine and low-dose cytarabine alternating with decitabine appears to be a safe and highly effective regimen for the treatment of elderly or unfit patients with newly diagnosed AML. Further testing of this regimen is warranted, and could help to provide a new, effective option for reduced-intensity therapy in this population. FUNDING:Part supported by the National Institutes of Health.

The purine nucleoside analogues clofarabine and fludarabine are active in acute myeloid leukemia (AML). We conducted a phase I/II randomized study of idarubicin and cytarabine with either clofarabine (CIA) or fludarabine (FIA) for relapsed or refractory AML. Clofarabine 15 mg/m2 was identified as the recommended phase II dose. Eighty-one patients were assigned using adaptive randomization to CIA (n = 48) or FIA (n = 33). The complete response (CR)/CR without platelet recovery rate did not differ between CIA and FIA (38% versus 30%, respectively; p = .50). In both arms, more than half of patients who had received only one prior line of therapy achieved remission. The median event-free survival for CIA and FIA was 2.0 and 1.9 months (p = .48), and the median overall survival was 6.3 and 4.7 months, respectively (p = .28). No significant differences in adverse events or early mortality rates were observed. Overall, CIA and FIA resulted in similar response rates and survival in patients with relapsed/refractory AML.

The degree of somatic hypermutation, determined as percent deviation of immunoglobulin heavy chain gene variable region sequence from the germline (IGHV%), is an important prognostic factor in chronic lymphocytic leukaemia (CLL). Currently, a cut-off of 2% deviation or 98% sequence identity to germline in IGHV sequence is routinely used to dichotomize CLL patients into mutated and unmutated groups. Because dissimilar IGHV% cut-offs of 1-5% were identified in different studies, we wondered whether no cut-off should be applied and IGHV% treated as a continuous variable. We analysed the significance of IGHV% in 203 CLL patients enrolled on the original frontline fludarabine, cyclophosphamide and rituximab (FCR) trial with a median of 10 years follow-up. Using the Cox Proportional Hazard model, IGHV% was identified as a continuous variable that is significantly associated with progression-free (PFS) and overall survival (OS) (P

BackgroundOutcomes in patients with chronic myeloid leukemia in blast phase (CML-BP) are historically dismal. Herein, the authors sought to analyze the characteristics, prognostic factors, and survival outcomes in patients with CML-BP in the tyrosine kinase inhibitor (TKI) era.MethodsA total of 477 patients with CML-BP were treated with a TKI at some point during the course of their CML. Cox proportional hazard models identified characteristics that were predictive of survival. Overall survival and failure-free survival were assessed. Optimal cutoff points for specific parameters were identified using classification and regression tree (CART) analysis.ResultsThe median age of the patients was 53 years (range, 16-84 years) and 64% were male. Approximately 80% of patients initially were diagnosed in the chronic phase of CML at a median of 41 months (range, 0.7-298 months) before transformation to CML-BP. De novo CML-BP occurred in 71 patients. Approximately 72% of patients received TKI therapy before CML-BP. The initial therapy for CML-BP included a TKI alone (35%), a TKI with chemotherapy (46%), and non-TKI therapies (19%). The median overall survival was 12 months and the median failure-free survival was 5 months. In multivariate analysis, myeloid immunophenotype, prior TKI, age ≥58 years, lactate dehydrogenase level ≥1227 IU/L, platelet count

BACKGROUND: Fludarabine and clofarabine are purine nucleoside analogues with established clinical activity in patients with acute myeloid leukemia (AML). METHODS: Herein, the authors evaluated the efficacy and safety of idarubicin and cytarabine with either clofarabine (CIA) or fludarabine (FIA) in adults with newly diagnosed AML. Adults with newly diagnosed AML who were deemed suitable for intensive chemotherapy were randomized using a Bayesian adaptive design to receive CIA (106 patients) or FIA (76 patients). Patients received induction with idarubicin and cytarabine, plus either clofarabine or fludarabine. Responding patients could receive up to 6 cycles of consolidation therapy. Outcomes were compared with a historical cohort of patients who received idarubicin and cytarabine. RESULTS: The complete remission/complete remission without platelet recovery rate was similar among patients in the CIA and FIA arms (80% and 82%, respectively). The median event-free survival was 13 months and 12 months, respectively (P = .91), and the median overall survival was 24 months and not reached, respectively (P = .23), in the 2 treatment arms. CIA was associated with more adverse events, particularly transaminase elevation, hyperbilirubinemia, and rash. Early mortality was similar in the 2 arms (60-day mortality rate of 4% for CIA vs 1% for FIA; P = .32). In an exploratory analysis of patients aged

BACKGROUND: Tumor protein 53 (TP53) mutations are uncommon in adult patients with acute lymphoblastic leukemia (ALL) and predict a poor outcome. METHODS: TP53 mutation analysis was performed in 164 newly diagnosed adult patients with ALL using a combination of targeted amplicon-based next-generation sequencing and Sanger sequencing. RESULTS: TP53 mutations were detected in 25 patients (15%), with a median allelic frequency of 42.2% (range, 5.6%-93.8%). The majority of mutations were single-nucleotide variants of missense type and involved the DNA-binding domain. TP53-mutated (TP53mut ) ALL was found to be significantly associated with older age, lower median white blood cell and platelet counts, lower frequency of Philadelphia chromosome and a higher frequency of low hypodiploid karyotype compared with ALL with wild-type TP53 (TP53wt ). To evaluate the prognostic effect of TP53 mutations, the authors selected 146 patients with B-cell immunophenotype ALL (24 with TP53mut and 122 with TP53wt ) who were uniformly treated with frontline hyperfractionated cyclophosphamide, vincristine, doxorubicin, and dexamethasone (hyper-CVAD)-based regimens; >90% of these individuals also received a monoclonal antibody. Over a median follow-up duration of 15 months, there was no significant difference in the median overall survival, event-free survival, and duration of complete remission noted between patients with TP53mut ALL and those with TP53wt ALL. CONCLUSIONS: Hyper-CVAD-based regimens appear to negate the poor prognostic impact of TP53 mutations in patients with adult B-cell immunophenotype ALL. Cancer 2017;123:3717-24. © 2017 American Cancer Society.

Central nervous system (CNS) relapse is uncommon in patients with acute myeloid leukemia (AML) with the use of high-dose cytarabine containing chemotherapy regimens. The clinical and molecular features associated with a higher risk of CNS relapse are not well defined. We assessed the incidence and outcome of CNS relapses among 1245 patients with relapsed/refractory AML referred to our institution between 2000 and 2014. CNS leukemia relapse was observed in 51 patients (4.1%). Using a multivariate regression model and after adjusting for age, FLT3-ITD mutation (OR = 2.33; P = .02) and elevated LDH (>1000 IU/L, OR = 1.99; P = .04) were independent predictive factors for CNS relapse. Patients under 64 years of age with 0, 1, or 2 baseline adverse features had a probability of 3.8%, 7.0%-8.0%, and 13.9% for developing CNS disease, respectively. Our study identifies patients with AML at higher risk for CNS relapse in whom prophylactic CNS therapy may be warranted.

BackgroundIbrutinib is a Bruton tyrosine kinase inhibitor and is approved for the treatment of patients with chronic lymphocytic leukemia (CLL) in frontline and relapsed/refractory settings. The authors previously reported poor outcomes for patients who discontinued ibrutinib; however, long-term outcomes were not reported.MethodsData from 320 patients who received ibrutinib on clinical studies between 2010 and 2015 at The University of Texas MD Anderson Cancer Center were retrospectively analyzed.ResultsLong-term outcomes among patients with CLL after they discontinued ibrutinib were analyzed. Ninety of 320 patients (28%) who were treated on ibrutinib-based regimens discontinued ibrutinib. Of these, 80 had relapsed/refractory disease, and 10 were treatment-naive. The median time to discontinuation was 15 months (range, 1.2-54 months). After a median follow-up of 38 months after starting ibrutinib, 40 patients (44%) remained alive. Major reasons for ibrutinib discontinuation were intolerance (n = 29; 32%), miscellaneous (n = 28; 31%), progression (n = 19; 21%), and Richter transformation (RT) (n = 9; 10%). The median survival according to the reason for discontinuation was 33 months for ibrutinib intolerance, 11 months for miscellaneous causes, 16 months for progressive CLL, and 2 months for RT. Among the 19 patients who had progressive CLL, 42% responded to subsequent therapy.ConclusionsIbrutinib discontinuation was observed during therapy. Patients with CLL who had disease transformation had especially poor outcomes, whereas those who developed progressive disease during ibrutinib therapy had a median survival of

Background: Ibrutinib is an active therapy with an acceptable safety profile for patients with chronic lymphocytic leukemia (CLL), including high-risk patients with del17p or with TP53 mutations. Ibrutinib is broadly indicated for the treatment of patients with CLL and specifically including those with 17p deletion. The optimal use of ibrutinib in combination with other agents remains controversial.Experimental Design: We report the long-term outcome [median follow-up of 47 months (range, 36-51 months)] of 40 patients with high-risk CLL, treated on the first ibrutinib combination trial with rituximab (IR). The majority of patients (36/40) were previously treated.Results: Median age was 65 years, and 21 patients (52%) had 17p deletion. Median duration on treatment was 41 months (range, 2-51 months), and median number of treatment cycles was 42 (range, 2-49). Overall response rate was 95%, and 9 patients (23%) attained a complete remission. Twenty-one patients discontinued treatment, 10 due to disease progression, 9 for other causes, and 2 due to stem cell transplantation; the remaining 19 patients continue on ibrutinib. Median progression-free survival for all patients was 45 months, which was significantly shorter in the subgroup of patients with del17p (n = 21, 32.3 months, P = 0.02). Fourteen patients (35%) died, five from progressive disease, five from infections, and four from other causes. Median overall survival has not been reached.Conclusions: IR combination therapy leads to durable remissions in high-risk CLL; the possible benefit from the addition of rituximab is currently explored in a randomized trial. Clin Cancer Res; 23(9); 2154-8. ©2016 AACR.

There is limited information regarding the immunological predictors of post-allogeneic stem cell transplant (alloSCT) outcome in chronic lymphocytic leukaemia (CLL), such as mixed T-cell chimerism. We analysed 143 consecutive patients with relapsed/refractory CLL, transplanted between 2000 and 2012, to determine the prognostic relevance of mixed chimerism post-alloSCT and the ability of post-transplant immunomodulation to treat relapse. Mixed T-cell chimerism occurred in 50% of patients at 3 months and 43% at 6 months post-alloSCT; upon 3- and 6-month landmark analysis, this was associated with inferior progression-free survival (PFS) [Hazard ratio (HR) 1·93, P = 0·003 and HR 2·58, P

In chronic lymphocytic leukemia (CLL), STAT3 is constitutively phosphorylated on serine 727 and plays a role in the pathobiology of CLL. However, what induces constitutive phosphorylation of STAT3 is currently unknown. Mass spectrometry was used to identify casein kinase 2 (CK2), a serine/threonine kinase that coimmunoprecipitated with serine phosphorylated STAT3 (pSTAT3). Furthermore, activated CK2 incubated with recombinant STAT3 induced phosphorylation of STAT3 on serine 727. Although STAT3 and CK2 are present in normal B- and T cells, STAT3 is not constitutively phosphorylated in these cells. Further study found that CD5 and BLNK coexpressed in CLL, but not in normal B- or T cells, are required for STAT3 phosphorylation. To elucidate the relationship of CD5 and BLNK to CK2 and STAT3, STAT3 was immunoprecipitated from CLL cells, and CK2, CD5, and BLNK were detected in the immunoprecipitate. Conversely, STAT3, CD5, and BLNK were in the immunoprecipitate of CLL cells immunoprecipitated with CK2 antibodies. Furthermore, siRNA knockdown of CD5 or BLNK, or treatment with CD5-neutralizing antibodies significantly reduced the levels of serine pSTAT3 in CLL cells. Finally, confocal microscopy determined that CD5 is cell membrane bound, and fractionation studies revealed that the CK2/CD5/BLNK/STAT3 complex remains in the cytoplasm, whereas serine pSTAT3 is shuttled to the nucleus.Implications: These data show that the cellular proteins CK2, CD5, and BLNK are required for constitutive phosphorylation of STAT3 in CLL. Whether this protein complex phosphorylates other proteins or inhibiting its activity would have clinical benefit in patients has yet to be determined. Mol Cancer Res; 15(5); 610-8. ©2017 AACR.

BackgroundSome patients with chronic myeloid leukemia (CML) have a history of previous malignancies. To the authors' knowledge, outcomes for CML diagnosed in these patients have not been well described. The current study was conducted to determine the outcome of patients with CML and a history of prior malignancies.MethodsThe current study included patients who were enrolled in clinical trials of tyrosine kinase inhibitors as initial therapy for CML in chronic phase from July 2000 to January 2014.ResultsOf the 630 patients with CML who were treated with frontline tyrosine kinase inhibitors, 626 had a known prior malignancy status. Of these, 45 patients (7%) had a prior malignancy other than nonmelanoma skin cancer whereas 17 patients (3%) had a history of nonmelanoma skin cancers alone. Characteristics of CML were similar between the patients with no prior malignancy, those with a prior malignancy, and those with nonmelanoma skin cancer. Patients with a prior malignancy were found to have an older median age compared with the other 2 groups. The most common prior malignancies were nonmelanoma skin cancer in 20 patients, breast cancer in 11 patients, melanoma in 7 patients, prostate cancer in 6 patients, and colorectal cancer in 5 patients. With regard to CML, the event-free survival, transformation-free survival, and failure-free survival rates were found to be similar between the groups. There was a statistically significantly decreased survival in the group with a prior malignancy versus the group with no prior malignancy versus the group with nonmelanoma skin cancer. In a multivariate analysis, advanced age and an elevated creatinine level were found to be associated with worse survival after a diagnosis of CML.ConclusionsPatients with CML with a history of prior malignancies appear to have the same excellent outcome as patients with no prior malignancies. In the few instances in which concomitant therapy for other malignancies was required during therapy with tyrosine kinase inhibitors, this was able to be accomplished without significant toxicity. Cancer 2017;123:609-616. © 2016 American Cancer Society.

The Bruton's tyrosine kinase inhibitor ibrutinib is a highly effective, new targeted therapy for chronic lymphocytic leukemia (CLL) that thwarts leukemia cell survival, growth, and tissue homing. The effects of ibrutinib treatment on the T cell compartment, which is clonally expanded and thought to support the growth of malignant B cells in CLL, are not fully characterized. Using next-generation sequencing technology, we characterized the diversity of TCRβ-chains in peripheral blood T cells from 15 CLL patients before and after 1 y of ibrutinib therapy. We noted elevated CD4+ and CD8+ T cell numbers and a restricted TCRβ repertoire in all pretreatment samples. After 1 y of ibrutinib therapy, elevated peripheral blood T cell numbers and T cell-related cytokine levels had normalized, and T cell repertoire diversity increased significantly. Dominant TCRβ clones in pretreatment samples declined or became undetectable, and the number of productive unique clones increased significantly during ibrutinib therapy, with the emergence of large numbers of low-frequency TCRβ clones. Importantly, broader TCR repertoire diversity was associated with clinical efficacy and lower rates of infections during ibrutinib therapy. These data demonstrate that ibrutinib therapy increases diversification of the T cell compartment in CLL patients, which contributes to cellular immune reconstitution.

BackgroundDisease-related symptoms impair the quality of life of patients with chronic lymphocytic leukaemia (CLL) who do not require systemic therapy. Available therapies are not specifically aimed at symptom control. Because stimulation of the B-cell receptor activates JAK2 in CLL cells and the JAK2 inhibitor ruxolitinib improves symptoms in patients with myelofibrosis, we postulated that ruxolitinib would improve disease-related symptoms in patients with CLL. We did a phase 2 trial of ruxolitinib to test this hypothesis.MethodsSymptomatic patients with CLL who did not require systemic therapy were enrolled at MD Anderson Cancer Center (Houston, TX, USA) between Sept 15, 2014, and Sept 20, 2015. Participants were given 10 mg ruxolitinib orally twice a day. Scores on the Brief Fatigue Inventory (BFI), CLL module of the MD Anderson Symptom Inventory (MDASI) and symptom-associated interference in daily activities, were assessed before treatment and after 3 months. This trial is ongoing and is registered at ClinicalTrials.gov (NCT02131584).Findings41 patients (25 previously untreated for CLL and 16 previously treated) were enrolled. At 3 months, the mean percentage change from baseline in BFI score was 44·3% (SD 35·0, p

BCR signaling is a central pathogenetic pathway in chronic lymphocytic leukemia (CLL). Most CLL cells express BCRs of IgM and IgD isotypes, but the contribution of these isotypes to functional responses remains incompletely defined. We therefore investigated differences between IgM and IgD signaling in freshly isolated peripheral blood CLL cells and in CLL cells cultured with nurselike cells, a model that mimics the lymph node microenvironment. IgM signaling induced prolonged activation of ERK kinases and promoted CLL cell survival, CCL3 and CCL4 chemokine secretion, and downregulation of BCL6, the transcriptional repressor of CCL3 In contrast, IgD signaling induced activation of the cytoskeletal protein HS1, along with F-actin polymerization, which resulted in rapid receptor internalization and failure to support downstream responses, including CLL cell survival and chemokine secretion. IgM and IgD receptor downmodulation, HS1 and ERK activation, chemokine secretion, and BCL6 downregulation were also observed when CLL cells were cocultured with nurselike cells. The Bruton's tyrosine kinase inhibitor ibrutinib effectively inhibited both IgM and IgD isotype signaling. In conclusion, through a variety of functional readouts, we demonstrate very distinct outcomes of IgM and IgD isotype activation in CLL cells, providing novel insight into the regulation of BCR signaling in CLL.

BackgroundA high pretreatment β2 -microglobulin (B2M) level is associated with inferior survival outcomes in patients with chronic lymphocytic leukemia. However, to the authors' knowledge, the prognostic and predictive significance of changes in B2M during treatment have not been reported to date.MethodsThe authors analyzed 83 patients treated with ibrutinib-based regimens (66 with recurrent/refractory disease) and 198 treatment-naive patients who were treated with combined fludarabine, cyclophosphamide, and rituximab (FCR) to characterize changes in B2M and their relationship with clinical outcomes.ResultsB2M rapidly decreased during treatment with ibrutinib; on multivariable analysis, patients who received FCR (odds ratio, 0.40; 95% confidence interval [95% CI], 0.18-0.90 [P = .027]) were less likely to have normalized B2M at 6 months than patients treated with ibrutinib. On univariable analysis, normalization of B2M was associated with superior progression-free survival (PFS) from the 6-month landmark in patients treated with ibrutinib-based regimens and FCR. On multivariable analysis, failure to achieve normalized B2M at 6 months of treatment was associated with inferior PFS (hazard ratio, 16.9; 95% CI, 1.3-220.0 [P = .031]) for patients treated with ibrutinib, after adjusting for the effects of baseline B2M, stage of disease, fludarabine-refractory disease, and del(17p). In contrast, in patients treated with FCR, negative minimal residual disease status in the bone marrow was the only variable found to be significantly associated with superior PFS (hazard ratio, 0.28; 95% CI, 0.12-0.67 [P = .004]).ConclusionsNormalization of B2M at 6 months in patients treated with ibrutinib was found to be a useful predictor of subsequent PFS and may assist in clinical decision-making.

BackgroundCombination of chemotherapy with a tyrosine-kinase inhibitor is effective in the treatment of Philadelphia chromosome-positive acute lymphoblastic leukaemia. Ponatinib is a more potent BCR-ABL1 inhibitor than all other tyrosine-kinase inhibitors and selectively suppresses the resistant T315I clones. We examined the activity and safety of combining chemotherapy with ponatinib for patients with Philadelphia chromosome-positive acute lymphoblastic leukaemia in this continuing phase 2 trial.MethodsIn this single-centre, phase 2, single-arm trial, adult patients with previously untreated Philadelphia chromosome-positive acute lymphoblastic leukaemia were sequentially enrolled. Patients who had received fewer than two courses of previous chemotherapy with or without tyrosine-kinase inhibitors were also eligible. Patients had to be aged 18 years or older, have an Eastern Cooperative Oncology Group performance status of 2 or less, have normal cardiac function (defined by ejection fraction above 50%), and have adequate organ function (serum bilirubin ≤3·0 mg/dL and serum creatinine ≤3·0 mg/dL, unless higher concentrations were believed to be due to a tumour). Patients received eight cycles of hyperfractionated cyclophosphamide, vincristine, doxorubicin, and dexamethasone (hyper-CVAD) alternating with high-dose methotrexate and cytarabine every 21 days. Ponatinib 45 mg was given daily for the first 14 days of cycle 1 then continuously for the subsequent cycles. Patients in complete remission received maintenance with ponatinib 45 mg daily with vincristine and prednisone monthly for 2 years followed by ponatinib indefinitely. The primary endpoint for this study was event-free survival. The trial is registered at ClinicalTrials.gov, number NCT01424982.Findings37 patients were enrolled and treated from Nov 1, 2011, to Sept 1, 2013. 2-year event-free survival rate was 81% (95% CI 64-90). Grade 3 or more toxic effects included infections during induction (20 [54%] patients), increased aspartate aminotransferase and alanine aminotransferase concentration (14 [38%] patients), thrombotic events (three [8%]), myocardial infarction (three [8%]), hypertension (six [16%]), skin rash (eight [22%]), and pancreatitis (six [16%] patients). Two patients died from from myocardial infarction potentially related to treatment; another patient also died from myocardial infarction related to sepsis. Two further patients died, one from bleeding and another from infection, both deemed unrelated to treatment.InterpretationThe first results of this ongoing trial indicate that the combination of chemotherapy with ponatinib is effective in achieving early sustained remissions in patients with newly diagnosed Philadelphia chromosome-positive acute lymphoblastic leukaemia. New strategies, including dosing titration of ponatinib and optimised control of vascular risk factors, might further improve outcomes.FundingARIAD Pharmaceuticals Inc.

BackgroundFludarabine, cyclophosphamide, and rituximab (FCR) result in durable responses in patients with previously untreated chronic lymphocytic leukemia (CLL). Previous reports have suggested that in patients with relapsed CLL, a dose-intensified rituximab regimen increases response rates in comparison with standard-dose rituximab. It is unknown whether rituximab intensification of the FCR regimen will result in improved response rates and patient outcomes in patients with previously untreated CLL.MethodsA single-arm study was conducted to evaluate the safety and efficacy of a modified FCR regimen with multiple-dose rituximab (FCR3) in 65 patients with previously untreated CLL. The results were compared with those for a historical cohort treated with FCR.ResultsThe overall response rate to FCR3 was 97%, with 75% of the patients achieving a complete remission. Minimal residual disease negativity was achieved for 62% of the patients according to flow cytometry. The median time to progression (TTP) was 81 months, and the median overall survival (OS) was not reached, with 58% of the patients still alive at a median survivor follow-up of 9.7 years. Grade 3 or 4 neutropenia, grade 3 or 4 thrombocytopenia, and major infections were observed with 45%, 5%, and 1.9% of the FCR3 courses, respectively. Therapy-related myelodysplastic syndrome (t-MDS) or therapy-related acute myelogenous leukemia (t-AML) developed in 7 patients (11%; P < .01 vs the historical FCR cohort).ConclusionsIn patients with previously untreated CLL, FCR3 resulted in response rates, TTP, and OS similar to those of a historical cohort of patients treated with FCR. FCR3 was associated with an increased incidence of t-MDS/t-AML.

BackgroundIbrutinib is active in patients with relapsed/refractory (R/R) chronic lymphocytic leukemia (CLL). In patients treated with ibrutinib for R/R CLL, del(17p), identified by interphase fluorescence in situ hybridization (FISH), is associated with inferior progression-free survival despite equivalent initial response rates. Del(17p) is frequently associated with a complex metaphase karyotype (CKT); the prognostic significance of CKT in ibrutinib-treated patients has not been reported.MethodsThis study reviewed 88 patients treated for R/R CLL at The University of Texas MD Anderson Cancer Center with investigational ibrutinib-based regimens from 2010 to 2013. Pretreatment FISH and lipopolysaccharide-stimulated metaphase cytogenetic analysis were performed on bone marrow.ResultsAn adequate pretreatment metaphase karyotype was available for 56 of the 88 patients. The karyotype was complex in 21 of the 56 cases; 17 of the 21 had del(17p) according to FISH. The overall response rate, including partial remission with persistent lymphocytosis, was 94%; 18% had complete responses. In a multivariate analysis (MVA), only CKT was significantly associated with event-free survival (EFS; hazard ratio [HR], 6.6 [95% CI 1.7-25.6]; P = .006). Fludarabine-refractory CLL (HR, 6.9 [95% CI 1.8-27.1], P = .005) and CKT (HR 5.9 [95% CI 1.6-22.2], P = .008) were independently associated with inferior overall survival (OS) in MVA. Del(17p) by FISH was not significantly associated with EFS or OS in MVA.ConclusionsCKT is a powerful predictor of outcomes for ibrutinib-treated patients with R/R CLL and may be a stronger predictor of biological behavior than del(17p) by FISH. Because of their relatively poor outcomes, patients with CKT are ideal candidates for studies of consolidative treatment strategies or novel treatment combinations.

Patients with chronic lymphocytic leukemia (CLL) are known to have an increased incidence of second cancers, but the contribution of commonly used frontline therapies to the incidence of second cancers is unclear. We report on the characteristics, incidence, outcomes and factors associated with second cancers in 234 patients receiving fludarabine, cyclophosphamide and rituximab (FCR) based regimens in the frontline setting. The risk of second cancers was 2.38 times higher than the expected risk in the general population. Ninety-three patients (40%) had other cancers before and 66 patients (28%) after FCR. Rates of therapy related acute myeloid leukemia/myelodysplastic syndrome (t-AML/MDS) (5.1%) and Richter transformation (RT) (9%) were high, while solid tumors were not increased. Overall survival of patients with second cancers after frontline FCR was shorter (median of 4.5 years) compared to patients with and without prior cancers. Second cancer risk after frontline FCR is mainly due to high rates of t-AML/MDS and RT, and as speculated the survival of affected patients is shorter.

We have analyzed patients with previously untreated chronic lymphocytic leukemia with del11q fluorescence in situ hybridization (FISH) abnormality (n = 196) in this study. Detection of the 11q22.3 used a multicolor FISH technique. Patients with del11q fell into two major FISH subsets-sole del11q (n = 64) and del11q with del13q (n = 132). FISH subsets were compared using the median del11q FISH% (>58%, high vs. ≤58%, low). Overall survival (OS) and time to first treatment (TTFT) were estimated using Kaplan-Meier plots (log rank). Multivariate analysis was performed to assess the association between FISH% of del11q and outcomes. Patients with sole del11q were similar to del11q with del13q in terms of TTFT and OS. Patients with high FISH% of del11q had significantly shorter OS and TTFT as compared with patients with low FISH%, particularly in sole del11q; this negative impact of high FISH% of del11q on OS and TTFT was diminished with coexistent del13q. In multivariate analysis, high FISH% of del11q was a significant predictor for shorter OS and TTFT. A comparison of these del11q subsets with a separate cohort of (n = 673) previously untreated patients with sole del13q showed that the high FISH% del11q cohort had a significantly shorter TTFT and OS. In addition, bulky disease by physical examination or computed tomography imaging was infrequent at presentation in patients with del11q. High FISH% of del11q can reliably discriminate higher risk patients with chronic lymphocytic leukemia. Presence of coexistent del13q should be accounted for while prognosticating patients with del11q.

Although numerous studies highlighted the role of Epstein-Barr Virus (EBV) in B-cell transformation, the involvement of EBV proteins or genome in the development of the most frequent adult leukemia, chronic lymphocytic leukemia (CLL), has not yet been defined. We hypothesized that EBV microRNAs contribute to progression of CLL and demonstrated the presence of EBV miRNAs in B-cells, in paraffin-embedded bone marrow biopsies and in the plasma of patients with CLL by using three different methods (small RNA-sequencing, quantitative reverse transcription PCR [q-RT-PCR] and miRNAs in situ hybridization [miRNA-ISH]). We found that EBV miRNA BHRF1-1 expression levels were significantly higher in the plasma of patients with CLL compared with healthy individuals (p

PurposeAllogeneic stem-cell transplantation (SCT) induces long-term remission in a fraction of patients with high-risk chronic lymphocytic leukemia (CLL) or Richter's transformation (RT). Our purpose was to determine the outcomes of patients whose disease progressed after allogeneic SCT.Patients and methodsWe retrospectively analyzed the outcomes of 72 patients (52 with CLL and 20 with RT) who underwent allogeneic SCT between 1998 and 2011 and had documented progression after transplantation. Twenty-two (31%) never had a response, and 50 (69%) had a response but experienced relapse after a median of 7 months (range, 2 to 85 months). Forty-eight patients who were receiving or were candidates to receive post-SCT cell-based therapies were not included in this analysis.ResultsThe median age at time of transplantation was 58 years (range, 30 to 72 years). Sixty-two patients (86%) received more than two treatment regimens and 37 (51%) received more than three treatment regimens before SCT. Sixty-six patients (92%) had active disease at the time of transplantation. The 2- and 5-year survival rates were 67% and 38% (patients with CLL) and 36% and 0% (patients with RT). The patients who developed acute or chronic graft-versus-host disease had a longer overall survival (OS; P = .05). In a multivariable analysis, RT or low hemoglobin at the time of SCT predicted shorter OS. Chronic graft-versus-host disease and an initial response to SCT predicted longer OS.ConclusionPatients with CLL in whom allogeneic SCT fails may have a response to and benefit from salvage therapies, and their prognosis is relatively good.

UnlabelledWhile reviewing chronic lymphocytic leukemia (CLL) bone marrow slides, we identified cytoplasmic lipid vacuoles in CLL cells but not in normal B cells. Because lipoprotein lipase (LPL), which catalyzes hydrolysis of triglycerides into free fatty acids (FFA), is aberrantly expressed in CLL, we investigated whether LPL regulates the oxidative metabolic capacity of CLL cells. We found that unlike normal B cells, CLL cells metabolize FFAs. Because STAT3 is constitutively activated in CLL cells and because we identified putative STAT3 binding sites in the LPL promoter, we sought to determine whether STAT3 drives the aberrant expression of LPL. Transfection of luciferase reporter gene constructs driven by LPL promoter fragments into MM1 cells revealed that STAT3 activates the LPL promoter. In addition, chromatin immunoprecipitation confirmed that STAT3 binds to the LPL promoter. Furthermore, transfection of CLL cells with STAT3-shRNA downregulated LPL transcripts and protein levels, confirming that STAT3 activates the LPL gene. Finally, transfection of CLL cells with LPL-siRNAs decreased the capacity of CLL cells to oxidize FFAs and reduced cell viability.ImplicationsOur study suggests that CLL cells adopt their metabolism to oxidize FFA. Activated STAT3 induces LPL, which catalyzes the hydrolysis of triglycerides into FFA. Therefore, inhibition of STAT3 is likely to prevent the capacity of CLL cells to utilize FFA.

Two hundred and thirty-five consecutive patients presenting to a single center with acute myeloid leukemia (AML) or myelodysplastic syndrome (MDS) after breast cancer treatment were compared with matched patients with de novo AML or MDS. There was no significant difference in median overall survival (OS) times between patients with therapy-related AML and those with de novo AML (8.7 months vs.10.2 months; p = 0.17). Patients with therapy-related MDS had slightly lower median baseline platelet counts and a higher frequency of poor cytogenetics than those with de novo MDS, but the two groups had similar OS times (13.6 months vs. 18.9 months; p = 0.06). Multivariate analysis revealed that cytogenetic risk, baseline white blood cell count, age and performance status were predictive for OS time in AML and that cytogenetic risk and performance status were predictive for OS time in MDS. Having therapy-related disease is not an independent risk factor in patients with myeloid neoplasms and with a history of breast cancer. Clinical trials should be designed to serve both populations.

BackgroundPatients with relapsed chronic lymphocytic leukemia (CLL) often achieve response with chemoimmunotherapy but have short remission durations. Studies have shown that patients with CLL have increased angiogenesis in the microenvironment; levels of proangiogenic growth factors such as VEGF and/or angiopoietin-2 are also elevated. Increased angiogenesis correlates with poor outcome in CLL. Bevacizumab (B) is a humanized monoclonal antibody targeting VEGF-A.MethodsIn this study, we analyzed whether a combination of bevacizumab with fludarabine, cyclophosphamide, and rituximab chemoimmunotherapy (FCR-B) could improve outcomes in patients with relapsed CLL. Sixty-two patients were enrolled. The median age of the patients was 60 years (range, 31-84 years) and 40% had received >1 prior therapy for CLL. Sixty-one patients were evaluable for toxicity, and 57 were evaluable for response. Six cycles were planned; 36 patients (59%) completed ≥4-6 cycles of the regimen.ResultsThe overall response rate was 79%, with 13 (23%) complete remissions (CRs), 8 nodular partial remissions (14%), and 24 partial remissions (43%). The median progression-free survival and overall survival rates were 13.5 and 45 months, respectively. Grade 3 or 4 toxicities included febrile neutropenia (n = 40), infections (n = 21), thrombocytopenia (n = 18) and anemia (n = 9).ConclusionsResults with FCR-B were similar to those observed with an historical cohort of relapsed patients treated with FCR.

UnlabelledHere, it was determined that chronic lymphocytic leukemia (CLL) cells express the α subunit, but not the β subunit, of the granulocyte-macrophage colony-stimulating factor receptor (GM-CSFR/CSF2R). GM-CSFRα was detected on the surface, in the cytosol, and in the nucleus of CLL cells via confocal microscopy, cell fractionation, and GM-CSFRα antibody epitope mapping. Because STAT3 is frequently activated in CLL and the GM-CSFRα promoter harbors putative STAT3 consensus binding sites, MM1 cells were transfected with truncated forms of the GM-CSFRα promoter, then stimulated with IL6 to activate STAT3 and to identify STAT3-binding sites. Chromatin immunoprecipitation (ChIP) and an electoromobility shift assay (EMSA) confirmed STAT3 occupancy to those promoter regions in both IL6-stimulated MM1 and CLL cells. Transfection of MM1 cells with STAT3-siRNA or CLL cells with STAT3-shRNA significantly downregulated GM-CSFRα mRNA and protein levels. RNA transcripts, involved in regulating cell survival pathways, and the proteins KAP1 (TRIM28) and ISG15 coimmunoprecipitated with GM-CSFRα. GM-CSFRα-bound KAP1 enhanced the transcriptional activity of STAT3, whereas GM-CSFRα-bound ISG15 inhibited the NF-κB pathway. Nevertheless, overexpression of GM-CSFRα protected MM1 cells from dexamethasone-induced apoptosis, and GM-CSFRα knockdown induced apoptosis in CLL cells, suggesting that GM-CSFRα provides a ligand-independent survival advantage.ImplicationsConstitutively, activation of STAT3 induces the expression of GM-CSFRα that protects CLL cells from apoptosis, suggesting that inhibition of STAT3 or GM-CSFRα may benefit patients with CLL.