In vivo, ex vivo and in vitro dasatinib activity in chronic lymphocytic leukemia

Emerging Therapies in CLL in the Era of Precision Medicine

Over the past decade, the treatment landscape of CLL has vastly changed from the conventional FC (fludarabine and cyclophosphamide) and FCR (FC with rituximab) chemotherapies to targeted therapies, including inhibitors of Bruton tyrosine kinase (BTK) and phosphatidylinositol 3-kinase (PI3K) as well as inhibitors of BCL2. These treatment options dramatically improved clinical outcomes; however, not all patients respond well to these therapies, especially high-risk patients. Clinical trials of immune checkpoint inhibitors (PD-1, CTLA4) and chimeric antigen receptor T (CAR T) or NK (CAR NK) cell treatment have shown some efficacy; still, long-term outcomes and safety issues have yet to be determined. CLL remains an incurable disease. Thus, there are unmet needs to discover new molecular pathways with targeted or combination therapies to cure the disease. Large-scale genome-wide whole-exome and whole-genome sequencing studies have discovered genetic alterations associated with disease progression, refined the prognostic markers in CLL, identified mutations underlying drug resistance, and pointed out critical targets to treat the disease. More recently, transcriptome and proteome landscape characterization further stratified the disease and revealed novel therapeutic targets in CLL. In this review, we briefly summarize the past and present available single or combination therapies, focusing on potential emerging therapies to address the unmet clinical needs in CLL.

Single-cell RNA sequencing to explore composition of peripheral blood NK cells in patients with chronic myeloid leukemia in treatment-free remission

This study was to explore the role of NK cell subsets and gene expression in maintaining TFR status. We identified six types of NK cells in the PBMCs over both groups (healthy controls and patients with TFR). Gene Oncology analysis showed that up regulated genes were enriched in the categories of "immune response," "reaction to tumor cells," and "cytolysis." In addition, we found that the three NK cell subsets, mature and terminal NK cells, CD56 bright NK cells, and transitional NK cells, contained many significantly up regulated genes in both groups, and that CD56 bright NK cells and transitional NK cells in patients with CML-TFR were in a proliferating and activated state. Through single-cell RNA sequencing analysis, we confirmed that the mature and terminal, CD56 bright, and transitional subsets of NK cells play an indispensable role in maintaining TFR in patients with CML.

Case Report: Long-Term Survival of a Dog With Chronic Lymphocytic Leukemia Treated With Chlorambucil, Prednisolone, and Imatinib

A 7-year-old castrated male Poodle dog presented with chronic progressive lymphocytosis. Hematologic and peripheral blood smear findings included remarkable lymphocytosis with well-differentiated small lymphocytes. Cytology of bone marrow aspirate showed hypercellular integrity with infiltration of small mature lymphocytes, accounting for 45% of all nucleated cells. Flow cytometry of blood and marrow samples revealed neoplastic lymphocytes predominantly expressing the CD21 molecule. B-cell chronic lymphocytic leukemia (CLL) was diagnosed on an immunophenotypic analysis. Administrations of prednisolone and chlorambucil were initiated and the response was unremarkable. Therefore, additional treatment with imatinib was provided, which resolved the hematologic abnormalities associated with CLL. Flow cytometry after ~1 year of treatment showed normalization of the count of lymphocytes positive for CD21 and resolved hematologic lymphocytosis. The dog was followed-up for 2 years, and there were no severe adverse effects. This case indicates that imatinib may be a good option as an adjunctive therapy with prednisolone and chlorambucil treatment for CLL in dogs without treatment response.