abt-199 and alvocidib

Conventional chemotherapy with cytarabine and anthracycline (often referred to as "7+3") has been used for many years in the treatment of acute myeloid leukemia (AML). Despite meaningful advances in areas of supportive care and transplantation, little progress has been made in developing new chemotherapy options. In 2018, The Food and Drug Administration (FDA) of the US approved several novel agents for AML treatment as follows: ivosidenib, an inhibitor of isocitrate dehydrogenase-1; venetoclax, a potent inhibitor of bcl2; and glasdegib, an inhibitor of hedgehog signaling pathway. Moreover, clinical trials of alvocidib (flavopiridol), an inhibitor of the CDK9, pevonedistat, an inhibitor of NEDD8, and APR-246, a reactivator of mutant p53, are in progress. These agents will either be incorporated into the conventional 7+3 regimen or combined with hypomethylating agents to improve the outcome of AML therapy, and the results will guide the next stage of precision medicine in the treatment of AML.

Topics: Benzimidazoles; Bridged Bicyclo Compounds, Heterocyclic; Cyclopentanes; Drug Approval; Flavonoids; Glycine; Humans; Leukemia, Myeloid, Acute; Molecular Targeted Therapy; Phenylurea Compounds; Piperidines; Pyridines; Pyrimidines; Sulfonamides; United States; United States Food and Drug Administration

Half of a century ago, physicians managing chronic lymphocytic leukemia (CLL) recognized some of its presenting features such as lymphocytosis, lymphadenopathy, and splenomegaly. Subsequently, an enhanced understanding of the disease mechanisms involved in CLL led to new, more targeted treatments. There is now a plethora of treatments available for CLL. In this review article we discuss in detail several of the novel agents that are being studied or approved for the treatment of CLL including: phosphatidylinositol 3-kinase inhibitors (idelalisib and IPI-145), Bruton tyrosine kinase inhibitors (ibrutinib), B cell lymphoma 2 inhibitors (ABT-263 and ABT-199), new anti-CD20 monoclonal antibodies (obinutuzumab), cyclin-dependent kinase inhibitors (flavopiridol and dinaciclib), immunomodulators (lenalidomide) and chimeric antigen receptor T-cell therapy.

Topics: Adenine; Aniline Compounds; Antibodies, Monoclonal, Humanized; Antineoplastic Agents; Bridged Bicyclo Compounds, Heterocyclic; Cyclic N-Oxides; Flavonoids; Humans; Immunologic Factors; Indolizines; Isoquinolines; Lenalidomide; Leukemia, Lymphocytic, Chronic, B-Cell; Piperidines; Protein Kinase Inhibitors; Proto-Oncogene Proteins c-bcl-2; Purines; Pyrazoles; Pyridinium Compounds; Pyrimidines; Quinazolinones; Receptors, Antigen, T-Cell; Sulfonamides; Thalidomide

Topics: Antineoplastic Combined Chemotherapy Protocols; Bridged Bicyclo Compounds, Heterocyclic; Humans; Leukemia, Myeloid, Acute

Colorectal cancer (CRC) is one of the most common malignancies worldwide and is associated with poor prognosis and high mortality. Despite advances in treatment with chemotherapy, CRC remains a major cause of drug resistance-related cancer deaths. One of the main reasons for such resistance is dysregulation of Mcl-1 expression. In this study, we identified LZT-106 as a novel kinase inhibitor that was able to bind to CDK9 with potent inhibitory ability, and indirectly regulate the expression of Mcl-1. However, different regulatory profiles were observed between LZT-106 and the well-studied CDK9 inhibitor flavopiridol with regards to Mcl-1 inhibition. Via Western blotting, real-time PCR and immunoprecipitation, we confirmed that LZT-106 was also able to target GSK-3β signaling and facilitate the degradation of Mcl-1. And LZT-106 was shown to synergize with ABT-199 to induce apoptosis even in the RKO cell line that overexpressed Mcl-1. Finally, LZT-106 significantly inhibited tumor growth in a xenograft mouse model with minimal toxicity. Overall, our findings suggest that LZT-106 is a promising candidate drug for the treatment of patients with CRC.

Topics: Animals; Antineoplastic Agents; Apoptosis; Apoptosis Regulatory Proteins; Bridged Bicyclo Compounds, Heterocyclic; Cell Line; Cell Line, Tumor; Colorectal Neoplasms; Cyclin-Dependent Kinase 9; Down-Regulation; Flavonoids; Glycogen Synthase Kinase 3 beta; HCT116 Cells; HEK293 Cells; HT29 Cells; Humans; Mice; Mice, Inbred BALB C; Mice, Nude; Myeloid Cell Leukemia Sequence 1 Protein; Piperidines; Protein Kinase Inhibitors; Signal Transduction; Sulfonamides

Cytarabine (ara-C) is the major drug for the treatment of acute myeloid leukemia (AML), but cellular resistance to ara-C is a major obstacle to therapeutic success. The present study examined enhanced anti-apoptosis identified in 3 newly established nucleoside analogue-resistant leukemic cell line variants and approaches to overcoming this resistance.. HL-60 human AML cells were used to develop the ara-C- or clofarabine (CAFdA)-resistant variants. The Bcl-2 inhibitor venetoclax and the Mcl-1 inhibitor alvocidib were tested to determine whether they could reverse these cells' resistance.. A 10-fold ara-C-resistant HL-60 variant, a 4-fold CAFdA-resistant HL-60 variant, and a 30-fold CAFdA-resistant HL-60 variant were newly established. The variants demonstrated reduced deoxycytidine kinase and deoxyguanosine kinase expression, but intact expression of surface transporters (hENT1, hENT2, hCNT3). The variants exhibited lower expression of intracellular nucleoside analogue triphosphates compared with non-variant HL-60 cells. The variants also overexpressed Bcl-2 and Mcl-1. Venetoclax as a single agent was not cytotoxic to the resistant variants. Nevertheless, venetoclax with nucleoside analogs demonstrated synergistic cytotoxicity against the variants. Alvocidib as a single agent was cytotoxic to the cells. However, alvocidib induced G1 arrest and suppressed the cytotoxicity of the co-administered nucleoside analogs.. Three new nucleoside analogue-resistant HL-60 cell variants exhibited reduced production of intracellular analogue triphosphates and enhanced Bcl-2 and Mcl-1 expressions. Venetoclax combined with nucleoside analogs showed synergistic anti-leukemic effects and overcame the drug resistance.

Topics: Antineoplastic Combined Chemotherapy Protocols; Bridged Bicyclo Compounds, Heterocyclic; Cell Proliferation; Clofarabine; Cytarabine; Flavonoids; Humans; Leukemia, Myeloid, Acute; Piperidines; Sulfonamides

The BCL-2-specific BH3-mimetic ABT-199 (venetoclax) has been reported to be principally active against favourable-risk multiple myeloma (MM) cells, prompting efforts to extend its activity to include more resistant, higher-risk MM subsets.. Effects of the CDK9 inhibitor flavopiridol (FP; alvocidib) on responses to ABT-199 were examined in MM cells. Cell death and protein expression were evaluated by western blot and immunofluorescence. Xenograft models were used to study combination effects in vivo.. FP synergistically increased ABT-199 lethality in both ABT-199-sensitive and insensitive MM cells. FP blocked CDK9 activation/positive transcription elongation factor B phosphorylation, downregulated MCL-1, increased BCL-2/MCL-1 ratios, and upregulated BIM. MCL-1 ectopic expression or knockdown in MM cells significantly diminished or increased ABT-199 sensitivity, respectively. CDK9 knockdown triggered MCL-1 downregulation and increased ABT-199 activity, whereas BIM knockdown significantly reduced FP/ABT-199 lethality. FP also enhanced ABT-199 lethality in unfavourable prognosis primary MM cells. HS-5 cell co-culture failed to protect MM cells from the FP/ABT-199 regimen, suggesting circumvention of microenvironmental signals. Finally, FP/ABT-199 significantly increased survival in systemic xenograft and immune-competent MM models while exhibiting minimal toxicity.. These findings argue that CDK9 inhibitors, for example, FP may increase the antimyeloma activity of ABT-199, including in unfavourable-risk MM minimally responsive to ABT-199 alone.

Topics: Animals; Antineoplastic Agents; Antineoplastic Combined Chemotherapy Protocols; Apoptosis; Bcl-2-Like Protein 11; Bridged Bicyclo Compounds, Heterocyclic; Cell Line, Tumor; Cyclin-Dependent Kinase 9; Down-Regulation; Drug Resistance, Neoplasm; Drug Synergism; Flavonoids; Gene Knockdown Techniques; Humans; Mice; Multiple Myeloma; Myeloid Cell Leukemia Sequence 1 Protein; Neoplasm Transplantation; Piperidines; Primary Cell Culture; Proto-Oncogene Proteins c-bcl-2; Risk Assessment; Sulfonamides; Up-Regulation