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Concept: B-cell chronic lymphocytic leukemia

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Background The treatment of relapsed chronic lymphocytic leukemia (CLL) has resulted in few durable remissions. Bruton’s tyrosine kinase (BTK), an essential component of B-cell-receptor signaling, mediates interactions with the tumor microenvironment and promotes the survival and proliferation of CLL cells. Methods We conducted a phase 1b-2 multicenter study to assess the safety, efficacy, pharmacokinetics, and pharmacodynamics of ibrutinib (PCI-32765), a first-in-class, oral covalent inhibitor of BTK designed for treatment of B-cell cancers, in patients with relapsed or refractory CLL or small lymphocytic lymphoma. A total of 85 patients, the majority of whom were considered to have high-risk disease, received ibrutinib orally once daily; 51 received 420 mg, and 34 received 840 mg. Results Toxic effects were predominantly grade 1 or 2 and included transient diarrhea, fatigue, and upper respiratory tract infection; thus, patients could receive extended treatment with minimal hematologic toxic effects. The overall response rate was the same in the group that received 420 mg and the group that received 840 mg (71%), and an additional 20% and 15% of patients in the respective groups had a partial response with lymphocytosis. The response was independent of clinical and genomic risk factors present before treatment, including advanced-stage disease, the number of previous therapies, and the 17p13.1 deletion. At 26 months, the estimated progression-free survival rate was 75% and the rate of overall survival was 83%. Conclusions Ibrutinib was associated with a high frequency of durable remissions in patients with relapsed or refractory CLL and small lymphocytic lymphoma, including patients with high-risk genetic lesions. (Funded by Pharmacyclics and others; ClinicalTrials.gov number, NCT01105247 .).

Concepts: Cancer, Hematology, Leukemia, Lymphoma, Respiratory system, Blood disorders, Upper respiratory tract infection, B-cell chronic lymphocytic leukemia

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Background New treatments have improved outcomes for patients with relapsed chronic lymphocytic leukemia (CLL), but complete remissions remain uncommon. Venetoclax has a distinct mechanism of action; it targets BCL2, a protein central to the survival of CLL cells. Methods We conducted a phase 1 dose-escalation study of daily oral venetoclax in patients with relapsed or refractory CLL or small lymphocytic lymphoma (SLL) to assess safety, pharmacokinetic profile, and efficacy. In the dose-escalation phase, 56 patients received active treatment in one of eight dose groups that ranged from 150 to 1200 mg per day. In an expansion cohort, 60 additional patients were treated with a weekly stepwise ramp-up in doses as high as 400 mg per day. Results The majority of the study patients had received multiple previous treatments, and 89% had poor prognostic clinical or genetic features. Venetoclax was active at all dose levels. Clinical tumor lysis syndrome occurred in 3 of 56 patients in the dose-escalation cohort, with one death. After adjustments to the dose-escalation schedule, clinical tumor lysis syndrome did not occur in any of the 60 patients in the expansion cohort. Other toxic effects included mild diarrhea (in 52% of the patients), upper respiratory tract infection (in 48%), nausea (in 47%), and grade 3 or 4 neutropenia (in 41%). A maximum tolerated dose was not identified. Among the 116 patients who received venetoclax, 92 (79%) had a response. Response rates ranged from 71 to 79% among patients in subgroups with an adverse prognosis, including those with resistance to fludarabine, those with chromosome 17p deletions (deletion 17p CLL), and those with unmutated IGHV. Complete remissions occurred in 20% of the patients, including 5% who had no minimal residual disease on flow cytometry. The 15-month progression-free survival estimate for the 400-mg dose groups was 69%. Conclusions Selective targeting of BCL2 with venetoclax had a manageable safety profile and induced substantial responses in patients with relapsed CLL or SLL, including those with poor prognostic features. (Funded by AbbVie and Genentech; ClinicalTrials.gov number, NCT01328626 .).

Concepts: Oncology, Hematology, Leukemia, Respiratory system, Blood disorders, Upper respiratory tract, Upper respiratory tract infection, B-cell chronic lymphocytic leukemia

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ROR1 is an oncoembryonic orphan-receptor found on chronic lymphocytic leukemia (CLL) B cells, but not on normal post-partum tissues. ROR1 is a receptor for Wnt5a that may complex with TCL1, a co-activator of AKT that is able to promote development of CLL. We found the CLL cells of a few patients expressed negligible ROR1 (ROR1(Neg)), but expressed TCL1A at levels comparable to those of samples that expressed ROR1 (ROR1(Pos)). Transcriptome analyses revealed that ROR1(Neg) cases generally could be distinguished from those that were ROR1(Pos) in unsupervised gene-expression clustering analysis. Gene-set enrichment analyses demonstrated that ROR1(Neg) CLL had lower expression and activation of AKT-signaling pathways relative to ROR1(Pos) CLL, similar to what was noted for leukemia that respectively developed in TCL1 versus ROR1xTCL1 transgenic mice. In contrast to its effect on ROR1(Pos) CLL, Wnt5a did not enhance the proliferation, chemotaxis, or survival of ROR1(Neg) CLL. We examined the CLL cells from 1,568 patients, which we randomly assigned to a training or validation set of 797 or 771 cases, respectively. Using recursive partitioning, we defined a threshold for ROR1-surface-expression that could segregate samples of the training set into ROR1-Hi versus ROR1-Lo subgroups that differed significantly in their median treatment free survival (TFS). Using this threshold, we found that ROR1-Hi cases had a significantly shorter median TFS and overall survival than ROR1-Lo cases in the validation set. These data demonstrate that expression of ROR1 may promote leukemia-cell activation and survival and enhance disease progression in patients with CLL.

Concepts: Lymphocyte, Protein, Gene expression, B cell, Leukemia, Genetically modified organism, AKT1, B-cell chronic lymphocytic leukemia

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Chemoimmunotherapy has led to improved numbers of patients achieving disease response, and longer overall survival in young patients with chronic lymphocytic leukaemia; however, its application in elderly patients has been restricted by substantial myelosuppression and infection. We aimed to assess safety and activity of ibrutinib, an orally administered covalent inhibitor of Bruton tyrosine kinase (BTK), in treatment-naive patients aged 65 years and older with chronic lymphocytic leukaemia.

Concepts: Cancer, Protein kinase, Hematology, Leukemia, B-cell chronic lymphocytic leukemia, Small lymphocytic lymphoma

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We previously showed that MMP-9 overexpression impairs migration of primary CLL cells and MEC-1 cells transfected with MMP-9. To determine the contribution of non-proteolytic activities to this effect we generated MEC-1 transfectants stably expressing catalytically inactive MMP-9MutE (MMP-9MutE-cells). In xenograft models in mice, MMP-9MutE-cells showed impaired homing to spleen and bone marrow, compared to cells transfected with empty vector (Mock-cells). In vitro transendothelial and random migration of MMP-9MutE-cells were also reduced. Biochemical analyses indicated that RhoAGTPase and p-Akt were not downregulated by MMP-9MutE, at difference with MMP-9. However, MMP-9MutE-cells or primary cells incubated with MMP-9MutE had significantly reduced p-ERK and increased PTEN, accounting for the impaired migration. Our results emphasize the role of non-proteolytic MMP-9 functions contributing to CLL progression.

Concepts: White blood cell, Blood, Bone marrow, Hematology, Leukemia, In vitro, Blood disorders, B-cell chronic lymphocytic leukemia

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Skeletal erosion has been found to represent an independent prognostic indicator in patients with advanced stages of chronic lymphocytic leukaemia (CLL). Whether this phenomenon also occurs in early CLL phases and its underlying mechanisms have yet to be fully elucidated. In this study, we prospectively enrolled 36 consecutive treatment-naïve patients to analyse skeletal structure and bone marrow distribution using a computational approach to PET/CT images. This evaluation was combined with the analysis of RANK/RANKL loop activation in the leukemic clone, given recent reports on its role in CLL progression. Bone erosion was particularly evident in long bone shafts, progressively increased from Binet stage A to Binet stage C, and was correlated with both local expansion of metabolically active bone marrow documented by FDG uptake and with the number of RANKL + cells present in the circulating blood. In immune-deficient NOD/Shi-scid, γcnull (NSG) mice, administration of CLL cells caused an appreciable compact bone erosion that was prevented by Denosumab. CLL cell proliferation in vitro correlated with RANK expression and was impaired by Denosumab-mediated disruption of the RANK/RANKL loop. This study suggests an interaction between CLL cells and stromal elements able to simultaneously impair bone structure and increase proliferating potential of leukemic clone.

Concepts: White blood cell, Osteoporosis, Bone, Cancer, Bone marrow, Osteoclast, Leukemia, B-cell chronic lymphocytic leukemia

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Chronic lymphoid leukaemia (CLL) has a heterogeneous clinical course depending on many clinical and molecular prognostic markers, which play an important role in the selection of the best treatment option. So far, TP53 disruption is the key prognostic and predictive factor assisting treatment decisions, especially in the era of novel therapies. Asymptomatic patients in early stages of the disease will still benefit from watchful waiting. In the frontline setting, chemoimmunotherapy is still the standard care in the majority of standard risk CLL patients. New classes of drugs like kinase inhibitors and BCL-2 inhibitors (ibrutinib, idelalisib and venetoclax) are the treatment of choice in CLL patients with relapsed/refractory disease, with the exception of high risk disease, where the optimal treatment is frontline ibrutinib monotherapy. In the near future, integrating next generation sequencing into the routine diagnostics would help the development of individual CLL patient management and to choose an optimal treatment strategy. Orv Hetil. 2017; 158(41): 1620-1629.

Concepts: White blood cell, Medicine, Cancer, Medical terms, Patient, Leukemia, Blood disorders, B-cell chronic lymphocytic leukemia

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Dysregulation of microRNAs (miRNAs) plays an important role in the pathogenesis of chronic lymphocytic leukemia (CLL). The Eμ-TCL1 transgenic mouse develops a form of leukemia that is similar to the aggressive type of human B-CLL, and this valuable model has been widely used for testing novel therapeutic approaches. Here, we adopted this model to investigate the potential effects of miR-26a, miR-130an and antimiR-155 in CLL therapy. Improved delivery of miRNA molecules into CLL cells was obtained by developing a novel system based on lipid nanoparticles conjugated with an anti-CD38 monoclonal antibody. This methodology has proven to be highly effective in delivering miRNA molecules into leukemic cells. Short- and long-term experiments showed that miR-26a, miR-130a and anti-miR-155 increased apoptosis after in vitro and in vivo treatment. Of this miRNA panel, miR-26a was the most effective in reducing leukemic cell expansion. Following long-term treatment, apoptosis was readily detectable by analyzing cleavage of PARP and caspase-7. These effects could be directly attributed to miR-26a, as confirmed by significant downregulation of its proven targets, namely cyclin-dependent kinase 6 and Mcl1. The results of this study are relevant to two distinct areas. The first is related to the design of a technical strategy and to the selection of CD38 as a molecular target on CLL cells, both consenting efficient and specific intracellular transfer of miRNA. The original scientific finding inferred from the above approach is that miR-26a can elicit in vivo anti-leukemic activities mediated by increased apoptosis.Oncogene advance online publication, 7 August 2017; doi:10.1038/onc.2017.269.

Concepts: Immune system, Gene, MicroRNA, In vivo, Leukemia, In vitro, Blood disorders, B-cell chronic lymphocytic leukemia

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CD49d is a surface integrin that is expressed on chronic lymphocytic leukaemia (CLL) cells, and strongly correlates with more aggressive disease. Given its association with cell-cell adhesion and leucocyte trafficking, we hypothesized that patients with high CD49d expression would experience a clinical course dominated by lymphadenopathy. CD49d expression was measured by flow cytometry and considered positive if expressed by ≥30% of CLL cells. The study included 797 newly diagnosed CLL/small lymphocytic leukaemia patients; 279 (35%) were CD49d positive. CD49d-positive patients were more likely to present with lymphadenopathy (P < 0·001); a finding that persisted after adjusting for fluorescence in situ hybridisation (FISH) and IGHV mutation status [odds ratio (OR) 2·51; 95% confidence interval (CI) 1·64-3·83; P < 0·001]. Among CLL Rai 0 patients, CD49d positivity was associated with shorter time to development of lymphadenopathy (3·2 years vs not reached, P < 0·01). This association was maintained after adjusting for either FISH [hazard ratio (HR) 2·18; 95% CI 1·25-3·81; P = 0·006) or IGHV status (HR 2·02; 95% CI 1·11-3·69; P = 0·02) individually, but was attenuated when adjusting by both (HR 1·72; 95% CI 0·88-3·38; P = 0·11).These data demonstrate that CD49d-positive CLL patients experience a disease course dominated by lymphadenopathy. These findings could have implications for therapy selection and disease monitoring.

Concepts: Medicine, Gene expression, Epidemiology, Cancer, Hematology, Leukemia, Flow cytometry, B-cell chronic lymphocytic leukemia

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We present the case of a 51-year-old man who developed paraneoplastic pemphigus (PNP) in the context of chronic lymphocytic leukemia (CLL). His CLL was successfully controlled with ibrutinib. Concurrently, there was significant improvement of his PNP, suggesting that ibrutinib may be a very useful addition to the treatment options in this potentially life-threatening autoimmune disorder.

Concepts: Hematology, Leukemia, Blood disorders, B-cell chronic lymphocytic leukemia