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Oncotarget Aug 2017Despite prominent role of radiotherapy in lung cancer management, there is an urgent need for strategies increasing therapeutic efficacy. Reversible epigenetic changes...
Despite prominent role of radiotherapy in lung cancer management, there is an urgent need for strategies increasing therapeutic efficacy. Reversible epigenetic changes are promising targets for combination strategies using HDAC inhibitors (HDACi). Here we evaluated on two NSCLC cell lines, the antitumor effect of abexinostat, a novel pan HDACi combined with irradiation in normoxia and hypoxia, by clonogenic assays, demonstrating that abexinostat enhances radiosensitivity in a time dependent way with mean SER10 between 1.6 and 2.5 for A549 and H460. We found, by immunofluorescence staining, flow cytometry assays and western blotting, in abexinostat treated cells, increasing radio-induced caspase dependent apoptosis and persistent DNA double-strand breaks associated with decreased DNA damage signalling and repair. Interestingly, we demonstrated on nude mice xenografts that abexinostat potentiates tumor growth delay in combined modality treatments associating not only abexinostat and irradiation but also when adding cisplatin. Altogether, our data demonstrate and anti-tumor effect potentiation by abexinostat combined with irradiation in NSCLC. Moreover, our work suggests for the first time to our knowledge promising triple combination opportunities with HDACi, irradiation and cisplatin which deserves further investigations and could be of major interest in the treatment of NSCLC.
PubMed: 28915585
DOI: 10.18632/oncotarget.14813 -
Oncotarget Aug 2017Current treatments for advanced solid tumors tend to be only palliative. Although radiotherapy is administered with a curative intent, radioresistance and dose-limiting...
Current treatments for advanced solid tumors tend to be only palliative. Although radiotherapy is administered with a curative intent, radioresistance and dose-limiting toxicities pose limitations to treatment. Abexinostat, an oral pan-histone deacetylase inhibitor, demonstrated enhanced sensitivity to radiation in various solid tumor cell lines. We conducted an exploratory, phase 1, dose-escalation study of abexinostat in combination with standard hypofractionated radiotherapy in patients with advanced solid tumors treated in a palliative setting. Among 58 treated patients, the median age was 61.5 years (range, 20-82); 47% of the patients had M1 stage disease, and 95% had received previous chemotherapy alone or chemotherapy in combination with surgery and/or radiotherapy. The recommended phase 2 dose was determined to be 90 mg/m (140 mg). Of the 51 patients evaluable for response, best overall response was 8% (1 complete response [CR], 3 partial responses [PRs]), and best loco-regional response was 12% (1 CR and 5 PRs) at a median follow-up of 16 weeks. Of note, patients with target or non-target brain lesions showed encouraging responses, with 1 patient achieving a best loco-regional response of CR. Treatment-emergent grade ≥3 adverse events (AEs) were few, with most common being thrombocytopenia (17%), lymphopenia (12%), and hypokalemia (7%). Six patients (10%) discontinued treatment due to AEs. No grade ≥3 prolongation of the QTc interval was observed, with no treatment discontinuations due to this AE. Oral abexinostat combined with radiotherapy was well tolerated in patients with advanced solid tumors. The combination may have potential for treatment of patients with brain lesions.
PubMed: 28915584
DOI: 10.18632/oncotarget.14147 -
Magyar Onkologia Mar 2017The therapy of lymphomas has undergone a major expansion during the last decade. Novel therapeutic targets have appeared beyond classical chemotherapeutic combinations.... (Review)
Review
The therapy of lymphomas has undergone a major expansion during the last decade. Novel therapeutic targets have appeared beyond classical chemotherapeutic combinations. These novel drugs have very pronounced action across lymphoma types, and their toxicity profile is usually better tolerable compared to standard chemotherapies. These new therapies are enabling us to offer treatment to those patients who have refractory disease, and we had no option to treat them before these drugs. The author describes several new therapeutic options. New chemotherapeutic drugs are pixantrone and bendamustin. Monoclonal antibodies, like rituximab, ofatumumab, obinotuzumab are described, and conjugated antibodies like brentuximab vedotin and inotuzumab ozogamicin are also discussed. The bispecific antibody blinatumomab can modulate the immune response, and the new class of immune checkpoint inhibitors (pembrolizumab, nivolumab) is also discussed. Therapies targeting the epigenetic regulatory network are also important. Several studies reported promising results of abexinostat, vorinostat, belinostat and panobinostat. The new class of immunomodulatory drugs (imids) is also growing, results with thalidomid and lenalidomid are discussed. The proteasome inhibitors are offering new combinations, with the use of bortezomid, carfilzomib, ixazomib. All these new drugs described above offer to the physician several therapeutic options to better treat patients with lymphoma.
Topics: Antibodies, Monoclonal; Antineoplastic Agents; Humans; Immunologic Factors; Lymphoma; Proteasome Inhibitors
PubMed: 28273193
DOI: No ID Found -
Nature Reviews. Urology May 2017
Topics: Angiogenesis Inhibitors; Benzofurans; Histone Deacetylases; Humans; Hydroxamic Acids; Indazoles; Kidney Neoplasms; Pyrimidines; Sulfonamides
PubMed: 28266510
DOI: 10.1038/nrurol.2017.37 -
Journal of Clinical Oncology : Official... Apr 2017Purpose This phase I trial evaluated epigenetic modulation of vascular endothelial growth factor (VEGF) and hypoxia-inducible factor by using a histone deacetylase...
Inhibiting Histone Deacetylase as a Means to Reverse Resistance to Angiogenesis Inhibitors: Phase I Study of Abexinostat Plus Pazopanib in Advanced Solid Tumor Malignancies.
Purpose This phase I trial evaluated epigenetic modulation of vascular endothelial growth factor (VEGF) and hypoxia-inducible factor by using a histone deacetylase abexinostat in combination with pazopanib to enhance response and reverse resistance. Patients and Methods Pazopanib was administered once a day on days 1 to 28 and abexinostat was administered orally twice a day on days 1 to 5, 8 to 12, and 15 to 19 (schedule A) or on days 1 to 4, 8 to 11, and 15 to 18 (schedule B). Dose escalation (3 + 3 design) in all solid tumors was followed by dose expansion in renal cell carcinoma (RCC). Results Fifty-one patients with RCC (N = 22) were enrolled, including 30 (59%) with one or more lines of prior VEGF-targeting therapy. Five dose-limiting toxicities, including fatigue (n = 2), thrombocytopenia (n = 2), and elevated AST/ALT (n = 1), were observed with schedule A; one dose-limiting toxicity was observed (elevated AST/ALT) was observed with schedule B. Grade ≥ 3 related adverse events included fatigue (16%), thrombocytopenia (16%), and neutropenia (10%). The recommended phase II dose was established as abexinostat 45 mg/m twice a day administered per schedule B plus pazopanib 800 mg/d. Objective response rate was 21% overall and 27% in the RCC subset. Median duration of response was 9.1 months (1.2 to > 49 months). Eight patients (16%) had durable control of disease for > 12 months. Durable tumor regressions were observed in seven (70%) of 10 patients with pazopanib-refractory disease, including one patients with RCC with ongoing response > 3.5 years. Peripheral blood histone acetylation and HDAC2 gene expression were associated with durable response to treatment. Conclusion Abexinostat is well tolerated in combination with pazopanib, allowing prolonged exposure and promising durable responses in pazopanib- and other VEGF inhibitor-refractory tumors, which supports epigenetically mediated reversal of treatment resistance.
Topics: Acetylation; Adult; Aged; Alanine Transaminase; Angiogenesis Inhibitors; Antineoplastic Combined Chemotherapy Protocols; Aspartate Aminotransferases; Benzofurans; Carcinoma, Renal Cell; Disease Progression; Disease-Free Survival; Drug Resistance; Drug Resistance, Neoplasm; Epigenesis, Genetic; Fatigue; Female; Gene Expression; Histone Deacetylase 2; Histone Deacetylase Inhibitors; Histones; Humans; Hydroxamic Acids; Indazoles; Kidney Neoplasms; Male; Maximum Tolerated Dose; Middle Aged; Neutropenia; Pyrimidines; Sulfonamides; Thrombocytopenia; Treatment Outcome; Vascular Endothelial Growth Factor A; Young Adult
PubMed: 28221861
DOI: 10.1200/JCO.2016.70.5350 -
Haematologica May 2017Histone deacetylase inhibitors are members of a class of epigenetic drugs that have proven activity in T-cell malignancies, but little is known about their efficacy in...
Histone deacetylase inhibitors are members of a class of epigenetic drugs that have proven activity in T-cell malignancies, but little is known about their efficacy in B-cell lymphomas. Abexinostat is an orally available hydroxamate-containing histone deacetylase inhibitor that differs from approved inhibitors; its unique pharmacokinetic profile and oral dosing schedule, twice daily four hours apart, allows for continuous exposure at concentrations required to efficiently kill tumor cells. In this phase II study, patients with relapsed/refractory non-Hodgkin lymphoma or chronic lymphocytic leukemia received oral abexinostat at 80 mg BID for 14 days of a 21-day cycle and continued until progressive disease or unacceptable toxicity. A total of 100 patients with B-cell malignancies and T-cell lymphomas were enrolled between October 2011 and July 2014. All patients received at least one dose of study drug. Primary reasons for discontinuation included progressive disease (56%) and adverse events (25%). Grade 3 or over adverse events and any serious adverse events were reported in 88% and 73% of patients, respectively. The most frequently reported grade 3 or over treatment-emergent related adverse events were thrombocytopenia (80%), neutropenia (27%), and anemia (12%). Among the 87 patients evaluable for efficacy, overall response rate was 28% (complete response 5%), with highest responses observed in patients with follicular lymphoma (overall response rate 56%), T-cell lymphoma (overall response rate 40%), and diffuse large B-cell lymphoma (overall response rate 31%). Further investigation of the safety and efficacy of abexinostat in follicular lymphoma, T-cell lymphoma, and diffuse large B-cell lymphoma implementing a less dose-intense week-on-week-off schedule is warranted. ().
Topics: Adult; Aged; Aged, 80 and over; Benzofurans; Diarrhea; Disease-Free Survival; Drug Administration Schedule; Female; Histone Deacetylase Inhibitors; Humans; Hydroxamic Acids; Leukemia, Lymphocytic, Chronic, B-Cell; Lymphoma, Non-Hodgkin; Male; Middle Aged; Remission Induction; Thrombocytopenia; Treatment Outcome
PubMed: 28126962
DOI: 10.3324/haematol.2016.154377 -
Leukemia & Lymphoma Aug 2017Histone deacetylase (HDAC) inhibitor abexinostat is under investigation for the treatment of various cancers. Epigenetic changes including aberrant HDAC activity are...
Phase 1 dose-escalation study of oral abexinostat for the treatment of patients with relapsed/refractory higher-risk myelodysplastic syndromes, acute myeloid leukemia, or acute lymphoblastic leukemia.
Histone deacetylase (HDAC) inhibitor abexinostat is under investigation for the treatment of various cancers. Epigenetic changes including aberrant HDAC activity are associated with cancers, including myelodysplastic syndromes (MDS), acute myeloid leukemia (AML), and acute lymphoblastic leukemia (ALL). In this phase 1 dose-escalation study, 17 patients with relapsed/refractory higher-risk MDS, AML, or ALL received oral abexinostat (60, 80 [starting dose], 100, or 120 mg) twice daily (bid) on Days 1-14 of 21-day cycles. The most common treatment-related grade ≥3 adverse events were thrombocytopenia (29%) and neutropenia (24%), none of which led to discontinuation. Maximum-tolerated dose was not reached. Of 12 evaluable patients, best response was stable disease in 1 patient. This study was closed due to limited clinical benefit. Future development of oral abexinostat 100 mg bid in patients with MDS, AML, or ALL should focus on combination regimens. ISRCTN registry: 99680465.
Topics: Adult; Aged; Benzofurans; Drug Resistance, Neoplasm; Female; Histone Deacetylase Inhibitors; Humans; Hydroxamic Acids; Leukemia, Myeloid, Acute; Male; Middle Aged; Myelodysplastic Syndromes; Precursor Cell Lymphoblastic Leukemia-Lymphoma; Recurrence; Retreatment; Treatment Outcome; Young Adult
PubMed: 27911138
DOI: 10.1080/10428194.2016.1263843 -
Blood Dec 2016Bruton's tyrosine kinase (BTK) is a critical mediator of survival in B-cell neoplasms. Although BTK inhibitors have transformed therapy in chronic lymphocytic leukemia...
Bruton's tyrosine kinase (BTK) is a critical mediator of survival in B-cell neoplasms. Although BTK inhibitors have transformed therapy in chronic lymphocytic leukemia (CLL), patients with high-risk genetics are at risk for relapse and have a poor prognosis. Identification of novel therapeutic strategies for this group of patients is an urgent unmet clinical need, and therapies that target BTK via alternative mechanisms may fill this niche. Herein, we identify a set of microRNAs (miRs) that target BTK in primary CLL cells and show that the histone deacetylase (HDAC) repressor complex is recruited to these miR promoters to silence their expression. Targeting the HDACs by using either RNA interference against HDAC1 in CLL or a small molecule inhibitor (HDACi) in CLL and mantle cell lymphoma restored the expression of the BTK-targeting miRs with loss of BTK protein and downstream signaling and consequent cell death. We have also made the novel and clinically relevant discovery that inhibition of HDAC induces the BTK-targeting miRs in ibrutinib-sensitive and resistant CLL to effectively reduce both wild-type and C481S-mutant BTK. This finding identifies a novel strategy that may be promising as a therapeutic modality to eliminate the C481S-mutant BTK clone that drives resistance to ibrutinib and provides the rationale for a combination strategy that includes ibrutinib to dually target BTK to suppress its prosurvival signaling.
Topics: Adenine; Agammaglobulinaemia Tyrosine Kinase; Animals; Benzofurans; Cell Survival; Clone Cells; Drug Resistance, Neoplasm; Drug Synergism; Epigenesis, Genetic; Gene Expression Profiling; Gene Silencing; Histone Deacetylase Inhibitors; Humans; Hydroxamic Acids; Leukemia, Lymphocytic, Chronic, B-Cell; Mice, Inbred C57BL; MicroRNAs; Molecular Targeted Therapy; Mutant Proteins; Neoplasm Proteins; Piperidines; Promoter Regions, Genetic; Protein-Tyrosine Kinases; Pyrazoles; Pyrimidines; RNA Interference; Signal Transduction; Up-Regulation
PubMed: 27756747
DOI: 10.1182/blood-2016-07-727750 -
Biotechnology Letters Sep 2016To examine the effect of PCI-24781 (abexinostat) on the blastocyst formation rate in pig somatic cell nuclear transferred (SCNT) embryos and acetylation levels of the...
OBJECTIVE
To examine the effect of PCI-24781 (abexinostat) on the blastocyst formation rate in pig somatic cell nuclear transferred (SCNT) embryos and acetylation levels of the histone H3 lysine 9 and histone H4 lysine 12.
RESULTS
Treatment with 0.5 nM PCI-24781 for 6 h significantly improved the development of cloned embryos, in comparison to the control group (25.3 vs. 10.5 %, P < 0.05). Furthermore, PCI-24781 treatment led to elevated acetylation of H3K9 and H4K12. TUNEL assay and Hoechst 33342 staining revealed that the percentage of apoptotic cells in blastocysts was significantly lower in PCI-24781-treated SCNT embryos than in untreated embryos. Also, PCI-24781-treated embryos were transferred into three surrogate sows, one of whom became pregnant and two fetuses developed.
CONCLUSION
PCI-24781 improves nuclear reprogramming and the developmental potential of pig SCNT embryos.
Topics: Animals; Benzofurans; Embryo, Mammalian; Embryonic Development; Female; Histone Deacetylase Inhibitors; Hydroxamic Acids; Nuclear Transfer Techniques; Pregnancy; Swine
PubMed: 27271328
DOI: 10.1007/s10529-016-2141-0 -
Stem Cells Translational Medicine Aug 2016: The epigenetic mechanisms promoting lineage-specific commitment of human skeletal (mesenchymal or stromal) stem cells (hMSCs) into adipocytes or osteoblasts are still...
UNLABELLED
: The epigenetic mechanisms promoting lineage-specific commitment of human skeletal (mesenchymal or stromal) stem cells (hMSCs) into adipocytes or osteoblasts are still not fully understood. Herein, we performed an epigenetic library functional screen and identified several novel compounds, including abexinostat, which promoted adipocytic and osteoblastic differentiation of hMSCs. Using gene expression microarrays, chromatin immunoprecipitation for H3K9Ac combined with high-throughput DNA sequencing (ChIP-seq), and bioinformatics, we identified several key genes involved in regulating stem cell proliferation and differentiation that were targeted by abexinostat. Concordantly, ChIP-quantitative polymerase chain reaction revealed marked increase in H3K9Ac epigenetic mark on the promoter region of AdipoQ, FABP4, PPARγ, KLF15, CEBPA, SP7, and ALPL in abexinostat-treated hMSCs. Pharmacological inhibition of focal adhesion kinase (PF-573228) or insulin-like growth factor-1R/insulin receptor (NVP-AEW51) signaling exhibited significant inhibition of abexinostat-mediated adipocytic differentiation, whereas inhibition of WNT (XAV939) or transforming growth factor-β (SB505124) signaling abrogated abexinostat-mediated osteogenic differentiation of hMSCs. Our findings provide insight into the understanding of the relationship between the epigenetic effect of histone deacetylase inhibitors, transcription factors, and differentiation pathways governing adipocyte and osteoblast differentiation. Manipulating such pathways allows a novel use for epigenetic compounds in hMSC-based therapies and tissue engineering.
SIGNIFICANCE
This unbiased epigenetic library functional screen identified several novel compounds, including abexinostat, that promoted adipocytic and osteoblastic differentiation of human skeletal (mesenchymal or stromal) stem cells (hMSCs). These data provide new insight into the understanding of the relationship between the epigenetic effect of histone deacetylase inhibitors, transcription factors, and differentiation pathways controlling adipocyte and osteoblast differentiation of hMSCs. Manipulating such pathways allows a novel use for epigenetic compounds in hMSC-based therapies for tissue engineering, bone disease, obesity, and metabolic-disorders.
Topics: Adipocytes; Adipogenesis; Benzofurans; Cell Differentiation; Cell Line; Cell Lineage; Chromatin Immunoprecipitation; Computational Biology; Epigenesis, Genetic; Gene Expression Profiling; Gene Expression Regulation, Developmental; Gene Library; Genotype; Histone Deacetylase Inhibitors; Humans; Hydroxamic Acids; Mesenchymal Stem Cells; Myoblasts, Skeletal; Oligonucleotide Array Sequence Analysis; Osteoblasts; Osteogenesis; Phenotype; Signal Transduction; Transcription Factors
PubMed: 27194745
DOI: 10.5966/sctm.2015-0331