Search

Idelalisib is a first-in-class selective, oral, phosphatidylinositol 3-kinase delta (PI3Kδ) inhibitor approved for the treatment of several types of blood cancer. Idelalisib has demonstrated significant efficacy and a tolerable safety profile in clinical trials. However, the US prescribing information contains a black box warning for fatal and/or severe diarrhea or colitis, hepatotoxicity, pneumonitis and intestinal perforation. An expert panel was convened to review the pathology of these treatment-emergent adverse events (TEAEs) to propose key management tools for patients receiving idelalisib therapy. This article provides an overview of idelalisib TEAEs reported in clinical trials, and a summary of the panel's recommendations for identification and management of idelalisib treatment-emergent diarrhea or colitis as well as a discussion of transaminitis and pneumonitis. For idelalisib-related diarrhea or colitis (including unresolved grade 2 and grade ≥ 3), after exclusion of infectious causes, the panel recommends individualized treatment with budesonide or oral or intravenous steroid therapy.

Fludarabine, cyclophosphamide and rituximab (FCR), the standard of care for the frontline treatment of patients with chronic lymphocytic leukemia (CLL), is associated with a high rate of neutropenia and infectious complications. Granulocyte macrophage colony-stimulating factor (GM-CSF) reduces myelosuppression and can potentiate rituximab activity. We conducted a clinical trial combining GM-CSF with FCR for frontline treatment of 60 patients with CLL. Eighty-six percent completed all six courses and 18% discontinued GM-CSF for toxicity: grade 3-4 neutropenia was observed in 30% of cycles, and severe infections in 16% of cases. The overall response rate was 100%. Both median event-free survival (EFS) and overall survival (OS) have not been reached. Longer EFS was associated with favorable cytogenetics. GM-CSF led to a lower frequency of infectious complications than in the historical FCR group, albeit similar EFS and OS.

Chronic lymphocytic leukemia (CLL) is an indolent B-cell malignancy in which cells reside in bone marrow, lymph nodes, and peripheral blood, each of which provides a unique microenvironment. Although the levels of certain proteins are reported to induce, changes in the CLL cell proteome in the presence of bone marrow stromal cells have not been elucidated. Reverse-phase protein array analysis of CLL cells before and 24 h after stromal cell interaction revealed changed levels of proteins that regulate cell cycle, gene transcription, and protein translation. The most hit with respect to both the extent of change in expression level and statistical significance was caveolin-1, which was confirmed with immunoblotting. Caveolin-1 mRNA levels were also upregulated in CLL cells after stromal cell interaction. The induction of caveolin-1 levels was rapid and occurred as early as 1 h. Studies to determine the significance of upregulated caveolin-1 levels in CLL lymphocytes are warranted. [ABSTRACT FROM AUTHOR]

The article focuses on clinical trials for treatment of chronic lymphocytic leukemia (CLL) using combination of procaspase-activating compound B-PAC-1 and Axl inhibitor TP-0903 with ibrutinib. Topics discussed include accumulation of apoptotic-resistant lymphocytes in bone marrow and peripheral blood; requirement of Bruton's tyrosine kinase (BTK) for maintenance of CLL; and identification of pharmacologic agents like carfilzomib which induce apoptosis in lymphocytosed cells.

Chronic lymphocytic leukemia (CLL) and myeloproliferative neoplasms (MPN) may occur concomitantly. However, little is known about the pathobiological characteristics and interaction between the neoplastic clones in these rare cases of coinciding malignancies. We retrospectively examined the clinical and biological characteristics of 13 patients with concomitant CLL and MPN – eight primary myelofibrosis (PMF), three essential thrombocytosis (ET), and two polycythemia vera (PV) – who presented to our institution between 1998 and 2014, and tested all patients for MPN-specific aberrations, such asJAK2,MPLandCALRmutations. Along with epidemiological and molecular characterization of this rare condition, we found thatJAK2mutation can be detected 9 years prior to PMF diagnosis, suggesting that PMF clinical phenotype may require several years to develop and CLL/MPN clinical co-occurrence might be sustained by common molecular events. Some features of these patients suggest that pathobiologies of these diseases might be intertwined. [ABSTRACT FROM PUBLISHER]

Alterations in chronic lymphocytic leukemia (CLL) cell metabolism have been studied by several investigators. Unlike normal B lymphocytes or other leukemia cells, CLL cells, like adipocytes, store lipids and utilize free fatty acids (FFA) to produce chemical energy. None of the recently identified mutations in CLL directly affects metabolic pathways, suggesting that genetic alterations do not directly contribute to CLL cells’ metabolic reprogramming. Conversely, recent data suggest that activation of STAT3 or downregulation of microRNA-125 levels plays a crucial role in the utilization of FFA to meet the CLL cells’ metabolic needs. STAT3, known to be constitutively activated in CLL, increases the levels of lipoprotein lipase (LPL) that mediates lipoprotein uptake and shifts the CLL cells’ metabolism towards utilization of FFA. Herein, we review the evidence for altered lipid metabolism, increased mitochondrial activity and formation of reactive oxygen species (ROS) in CLL cells, and discuss the possible therapeutic strategies to inhibit lipid metabolism pathways in patient with CLL. [ABSTRACT FROM AUTHOR]

The Pim proteins are Ser/Thr kinases over-expressed in several hematological malignancies such as chronic lymphocytic leukemia (CLL) and some solid cancers like prostate cancer. Several small molecules have been developed to inhibit these kinases. In prostate cancer cell lines, the Pim kinase inhibitor SMI-4a and the Bcl-2 antagonist ABT-737 resulted in synergistic cytotoxicity. Akin to prostate cancer cells, CLL lymphocytes over-express Pim and Bcl-2 proteins. It was hypothesized that similar cytotoxic interaction should be observed in CLL. This study evaluated thein vitrocytotoxic effect of three Pim kinase inhibitors (AZD1208, SGI-1776 and SMI-4a) combined with Bcl-2 antagonists (ABT-737 or ABT-199) in malignant CLL lymphocytes. Data indicated Pim kinase inhibitors in combination with ABT-737 or ABT-199 resulted mostly in additive cytotoxicity with a few synergistic responses; however, the extent of synergism was less robust than that observed previously in prostate cancer cell lines treated with SMI-4a and ABT-737. [ABSTRACT FROM PUBLISHER]

Rituximab prolongs survival in many CD20-expressing B- lymphoid malignancies. In non-Hodgkin lymphoma (NHL), a large number of clinical studies have established the 375 mg/m2 dose of rituximab as standard. In chronic lymphocytic leukemia (CLL), response rates to single-agent rituximab at the NHL dose were low, but the use of higher doses or more frequent dosing have led to improved response rates, suggesting that a higher dose may be required. This led to the empiric decision to adopt rituximab at 500 mg/m2 in combination with fludarabine and cyclophosphamide (FC) in phase II and III trials in CLL. The final result was the approval of rituximab at 500 mg/m2 for treatment of CLL, in combination with FC. There is, however, preclinical evidence that full saturation of CD20 molecules may not be required to achieve chemosensitization in cancer cells, and it remains possible that the approved dose of 500 mg/m2 is higher than what is required to achieve maximal in vivo synergy. Nevertheless, all of the randomized evidence for superiority of rituximab plus chemotherapy over chemotherapy alone comes from studies using the 500 mg/m2 dose. [ABSTRACT FROM AUTHOR]