Here, we evaluated the activity of acalabrutinib (ACP-196) and ACP-319 (AMG-319), second generation inhibitors of Bruton tyrosine kinase (BTK) and PI3Kδ inhibitor, respectively, in lymphoma pre-clinical models.
New targeted therapies for hematological malignancy include chimeric antigen receptor T cells (CAR T cells), Bi-specific T-cell Engager (BiTE) blinatumomab, and the antibody-drug conjugate (ADC) of calicheamicin inotuzumab ozogamicin for acute lymphoblasic leukemia (ALL) and lymphoma; the Bruton's tyrosine kinase (BTK) inhibitor ibrutinib and phosphatidylinositol 3-kinase (PI3Kδ) inhibitor idelalisib for lymphoma and graft-versus-host disease (GVHD); FMS-like tyrosine kinase 3 (FLT3) inhibitors, such as midostaurin, sorafenib and gilteritinib for acute myeloid leukemia (AML); and the BCL-2 inhibitor venetoclax for a range of hematological malignancies including lymphoma and leukemia.
Although many PI3K inhibitors have reached different stages of clinical development, only two (idelalisib and copanlisib) have been currently approved for use in the treatment of B cell lymphoma and leukaemias.
IL-6-induced STAT3 or STAT5 activation is a critical mechanism underlying PI3K inhibitor resistance in lymphoma, supporting the utility of IL-6 as an effective biomarker to predict therapeutic response to PI3K inhibitors.
In addition to being frequently genetically activated in cancer, similar mutations in class I PI3Ks have now also been found in a human non-malignant overgrowth syndrome and a primary immune disorder that predisposes to lymphoma.
We show here abundant nuclear expression of FOXO1 in Burkitt lymphoma (BL), a germinal center (GC) B-cell-derived lymphoma whose pathogenesis is linked to PI3K activation.
As bcl-2 proteins, cyclin dependent kinases (CDK) and phosphoinositol-3- kinase (PI3K) also influence mitochondrial physiology and metabolism with clear relevance to the pathogenesis of lymphoma, we investigated the potentiating effects of metformin when combined with novel agents Venetoclax (bcl-2 inhibitor), BAY-1143572 (CDK9 inhibitor) and Idelalisib (p110δ- PI3K inhibitor).
<b>Purpose:</b> Activation of the PI3K/mTOR signaling pathway is recurrent in different lymphoma types, and pharmacologic inhibition of the PI3K/mTOR pathway has shown activity in lymphoma patients.
Idelalisib is a PI3Kδ inhibitor that has been approved for the treatment of lymphoma and chronic lymphocytic leukemia in the relapsed/refractory setting, and several other PI3K inhibitors are being developed targeting other isoforms of the PI3K enzyme, which results in distinct toxicities and variable efficacy in the clinical setting.
We found that a novel PI3K δ isoform inhibitor TGR-1202, but not the approved PI3Kδ inhibitor idelalisib, was highly synergistic with the proteasome inhibitor carfilzomib in lymphoma, leukemia, and myeloma cell lines and primary lymphoma and leukemia cells.
Drugs for leukaemia or lymphoma therapy such as idelalisib, duvelisib and ibrutinib block PI3Kδ activity directly or indirectly, potentially affecting AID expression and, consequently, genomic stability in B cells.
Targeting the PI3K/mTOR pathway in several types of lymphoma has shown preclinical and clinical efficacy providing the rationale to test this strategy in the treatment of relapsed/refractory indolent lymphomas.
Here, we demonstrate that coordinated targeting of rDNA transcription and PI3K-AKT-mTORC1-dependent ribosome biogenesis and protein synthesis provides a remarkable improvement in survival in MYC-driven B lymphoma.
Constitutive activation of the phosphatidyl-inositol-3-kinase (PI3K)/Akt/mammalian target of rapamycin (mTOR) signaling pathway is often detected in this lymphoma.
As drug resistance remains a major challenge and CDK4 and PI3K are dysregulated at a high frequency in human cancers, targeting CDK4 in genome-based combination therapy represents a novel approach to lymphoma and cancer therapy.
The phosphatidylinositol-3-kinase (PI3K) / protein kinase B (AKT) signal transduction pathway is commonly misregulated in lymphoma and associated with tumorigenesis and enhanced resistance to radiotherapy.
Accordingly, miR-17~92-driven lymphoma cells exhibited constitutive activation of the PI3K and NFκB pathways and chemical inhibition of either pathway reduced tumour size and prolonged the survival of lymphoma-bearing mice.
Finally, HRS cells display deregulated expression of several genes potentially highly relevant to lymphoma pathogenesis, including silencing of the apoptosis-inducer BIK and of INPP5D, an inhibitor of the PI3K-driven oncogenic pathway.