Taken together, we provide chronic myeloid leukemia tailored BCR-ABL1p210 and BCR-ABL1p210/T315I fly model which can be used to test new compounds with improved therapeutic indices.
We also investigated the functional relevance of HMGCLL1 blockade with respect to response to TKI therapy and showed that small interfering RNA mediated blockade of HMGCLL1 isoform 3 results in significant decrease in viability of BCR-ABL1-positive cells including K562, CML-T1 or BaF3 cell lines with or without ABL1 kinase domain mutations such as T315I mutation.
In chronic myeloid leukemia (CML), resistance against second-generation tyrosine kinase inhibitors (TKI) remains a serious clinical challenge, especially in the context of multi-resistant BCR-ABL1 mutants, such as T315I.
Most remarkably, ATO/IFN significantly prolonged the survival of primary T315I-CML mice and displayed a dramatic impairment of disease engraftment in secondary mice, which reflected decreased LIC activity.
HQP1351, an orally bioavailable multikinase BCR-ABL inhibitor, is currently in clinical trials for the treatment of T315I mutant chronic myelogenous leukemia (CML), but the potential application in imatinib-resistant GISTs carrying secondary KIT mutations has not been explored.
We assessed ponatinib for nine patients with recurrent Ph+ CNSL and a T315I mutation after allo-HSCT, including five patients with Ph+ acute lymphoblastic leukemia and four with chronic myelogenous leukemia.
HU and the CDK4/CDK6-blocker palbociclib inhibit growth of CML clones expressing BCR-ABL1<sup>T315I</sup> or complex T315I-including compound-mutations.
Ponatinib is a third-generation TKI that is currently approved as per label when no other TKIs are indicated for the treatment of patients with CML and Ph+ ALL after failing treatment with second-generation TKIs or if presence of T315I mutation is discovered.
Ponatinib is active against all BCR-ABL1 mutants, including T315I, and is widely used to treat patients who developed resistance to other TKIs in any CML phase; however, only limited data is available on the possible role of ponatinib for intolerant patients.
Discovery of (E)-N-(4-((4-methylpiperazin-1-yl)methyl)-3-(trifluoromethyl)phenyl)-3-((3-(2-(pyridin-2-yl)vinyl)-1H-indazol-6-yl)thio)propanamide (CHMFL-ABL-121) as a highly potent ABL kinase inhibitor capable of overcoming a variety of ABL mutants including T315I for chronic myeloid leukemia.
Ponatinib induces a sustained deep molecular response in a chronic myeloid leukaemia patient with an early relapse with a T315I mutation following allogeneic hematopoietic stem cell transplantation: a case report.
For this reason, ponatinib is currently indicated for the treatment of chronic myeloid leukaemia (CML) in every phase of disease resistant and/or intolerant to dasatinib and nilotinib and for whom imatinib is not indicated anymore or for patients with T315I mutation.
In the United States, ponatinib has received accelerated approval for adults with T315I-positive chronic myeloid leukemia (CML) or T315I (gatekeeper mutation)-positive, Philadelphia chromosome-positive, acute lymphoblastic leukemia (Ph + ALL), and patients with CML or Ph + ALL for whom no other TKI therapy is indicated.
Here we further report that (i) PtPT induces apoptosis in Bcr-Abl wild-type and Bcr-Abl-T315I mutation cells including the primary mononuclear cells from CML patients clinically resistant to IM, as well as inhibits the growth of IM-resistant Bcr-Abl-T315I xenografts in vivo; (ii) PtPT downregulates Bcr-Abl level through restraining Bcr-Abl transcription, and decreasing Bcr-Abl protein mediated by DUBs inhibition-induced caspase activation; (iii) UPS inhibition is required for PtPT-induced caspase activation and cell apoptosis.
We have now demonstrated that protein expression of human estrogen receptor alpha 36 (ERα36), an alternative splicing variant of human estrogen receptor alpha 66 (ERα66), is highly increased in TKI-insensitive CD34+ chronic myeloid leukemia (CML) cells and BCR-ABL-T315I mutant cells, and is abnormally localized in plasma membrane and cytoplasm.
ARDAP derivative <b>10</b> inhibited the proliferation of BCR/ABL-expressing KU812 and LAMA84 cells from chronic myeloid leukemia (CML) patients in blast crisis and of hematopoietic cells ectopically expressing the imatinib mesylate (IM)-sensitive KBM5-WT or its IM-resistant KBM5-T315I mutation.
Taken together, our data demonstrate that the lower growth ability of KBM5-T315ICML cells might be related to the decreased expression of glycolysis-related genes and ROS levels, and this will be used to identify therapeutic targets for imatinib resistance in CML.
In a xenograft model, PD0332991, but not imatinib, suppressed dissemination of Ph(+) ALL having the T315I mutation and prolonged survival, demonstrating that this reagent would be a new therapeutic modality for relapsed CML-LC and Ph(+) ALL patients after treatment with tyrosine kinase inhibitors.
To our knowledge, this is the second case of a T315I-bearing chronic myeloid leukemia patient displaying satisfactory response to the combination therapy of dasatinib and IFN-α.
Bone marrow transplantation or ponatinib treatment are currently recommended strategies for management of patients with chronic myeloid leukemia (CML) harboring the T315I mutation and compound or polyclonal mutations.