Small-molecule Kinase Inhibitors Research Articles

Eosinophils Upregulate PD-L1 and PD-L2 Expression to Enhance the Immunosuppressive Microenvironment in Multiple Myeloma

Multiple myeloma is a clonal proliferation of malignant plasma cells and in the vast majority of patients remains incurable. The biology of the malignant plasma cells (PCs) in multiple myeloma (MM) is highly influenced by the bone marrow (BM) microenvironment in which they reside. Specifically, BM stromal cells (SCs) have been shown to interact with MM cells to promote their growth, survival and resistance to conventional chemotherapy. In contrast, it remains unclear how the BM microenvironment modulates the response of MM cells to novel agents, such as proteasome inhibitors or responses to innate immune cells. Moreover, it remains unclear which specific cell types within the BM modulate the therapeutic response of MM cells.MM cell lines and patient tumor cells co-cultured with BM and BM-derived eosinophils demonstrated increased growth, proliferation and survival in the presence of the proteasome inhibitors bortezomib and carfilzomib. BM eosinophils have been reported to support the survival of plasma cells by secreting APRIL (a pr oliferation- i nducing l igand), among other growth factors, and contribute to the long-term maintenance of malignant plasma cells. Results indicated that addition of APRIL to MM cultures increased cell proliferation.Targeting immune checkpoints such as programmed cell death protein 1 (PD-1), programmed cell death 1 ligand 1 (PD-L1) and PD-L2 has achieved noteworthy benefit in multiple cancers by blocking immuno-inhibitory signals and enabling patients to produce an effective antitumor response. Programmed death-ligand 1 (PD-L1) and PD-L2 are ligands for the receptor PD-1 within a negative costimulatory network that leads to a T cell exhaustion phenotype, preventing appropriate cellular response to antigens. Treatment with patient BM, BM-derived eosinophils or APRIL led to a substantial upregulation of PD-L1 and PD-L2 on the surface of MM cells (Fig. 1A, B). Furthermore, pre-treatment of MM cells with eosinophils or APRIL suppressed anti-tumor immunity by cytotoxic T lymphocytes (CTLs). shRNA-mediated knockdown of PD-L1 and PD-L2 on MM cells enhanced the cytotoxic effect of CTLs (Fig. 1C). Treatment with the FDA-approved proteasome inhibitors bortezomib, carfilzomib and ixazomib also dramatically and rapidly upregulated PD-L1 and PD-l2 levels on MM cells. Treatment of MM cells with proteasome inhibitors also compromised the anti-myeloma effect of CD8+ T cells. Chemical compound screening was then performed and revealed that small molecule kinase inhibitors that suppressed the basal and drug-induced expression of PD-L1 and PD-L2 on MM cells. Novel small molecule kinase inhibitors that suppressed PD-L1 and PD-L2 on MM cells also triggered CTL activation with antimyeloma benefit.Conclusions: BM-derived eosinophils enhanced immuno-suppressive microenvironmental effects and promoted resistance of MM cells to all proteasome inhibitors tested. APRIL, secreted by eosinophils, promoted MM growth and upregulated the checkpoint proteins PD-L1 and PD-L2 on MM cells. Thus, standard-of-care antimyeloma agents such as proteasome inhibitors as well as the BM-secreted cytokine APRIL suppressed antimyeloma immunity. Antibody-mediated blockade of the PD-L1/PD-L2~PD-1 axis restores antitumor immunity in cancer patients with therapeutic benefit, but exhibits numerous adverse side effects. The development of novel small molecules that suppress checkpoint proteins on MM cells may overcome the drawbacks associated with monoclonal-based checkpoint inhibitors to provide greater specificity, increased tumor response rates and fine-tune therapy while managing adverse events. Small molecules also provide increased oral bioavailability and higher stability at ambient temperature facilitating purification during clinical production. Kinase inhibitors that suppress PD-L1 and PD-L2 to promote antimyeloma immune effects may also limit tumor progression in immunocompetent murine models of myeloma. [Display omitted] DisclosuresMalek:Takeda: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Sanofi: Membership on an entity's Board of Directors or advisory committees; Celgene: Speakers Bureau.

Integrated Functional Genomic and Pharmacological Characterization of the Kinome of Myeloma Cells

Small molecule kinase Inhibitors represent the main therapeutic modality for targeting aberrant kinase signaling in cancer. The recent emergence of CRISPR/Cas9 based functional genomic tools facilitates the genome-wide assessment of cancer cell dependencies, and evaluation of the relative dependence of tumor cells on diverse types of kinases inhibited by small molecule agents with different specificities, as well as other kinases for which selective inhibitors may not be currently available. In this study, we integrated the phenotypic information from the response of multiple myeloma cell lines to small molecule kinase inhibitors (16 MM cell lines, cultured in the presence vs. absence of stromal cells, using a panel of 273 kinase inhibitors (100nM, 24-72 h exposure; targeting a total of 43 known primary oncogenic targets) vs. CRISPR-based functional data on the relative dependency of MM lines on the respective targets of these inhibitors. The cell-autonomous activity of the various inhibitors was broadly potent for Aurora, PLK, and mTORC1/2 inhibitors, consistent with the high proliferative rates of MM cell lines in vitro and the role of the corresponding genes as broad-spectrum dependencies across not only MM, but also a collection of 300+ cell lines from other neoplasias. We observed virtually no anti-MM in vitro activity for selective inhibitors of c-met, ALK, EGFR, c-kit, PDGFR, VEGFR, Syk, Src, and BTK (even in cell lines with detectable transcripts for the respective kinases):, consistent with these results, the corresponding kinases genes were not essential for in vitro survival and proliferation of MM cell lines in our CRISPR studies. We observed modest to minimal response to selective pharmacological inhibitors for PDK1, PI3K (excluding those that also inhibit mTOR), and Akt. Interestingly, at the functional genomic level, PI3KCA was a prominent dependency (and more pronounced than other PI3K isoforms) for several MM cell lines, while individual isoforms of AKT were typically not essential genes for most or all of the MM cell lines tested, suggesting potential redundancy between these isoforms or feedback loops as bypass mechanisms attenuating the effect of pharmacological inhibitors. Prominent and selective MM kinase dependencies at the functional genomic level include PIM2 (providing indirect explanation for the clinical activity observed in Phase 1 trials in MM of a pan-PIM inhibitor) and IKBKB (consistent with the role of the NFKB pathway in MM). Consistent with prior studies on small inhibitors against IGF1R, its gene is a dependency in most MM lines tested and one of the most recurrent dependencies among receptor tyrosine kinases. Both pharmacological and CRISPR-based results suggest heterogeneous responses of MM cells to loss-of-function of MEK1/2 and, more broadly to diverse members of the MAPK family. Comparison of pharmacological results obtained in the presence vs. absence of stroma, indicate heterogeneous effect of bone marrow stromal cells on MM cell response to inhibitors across different targets and cell lines, including stroma-induced resistance to the same kinase inhibitor for some cell lines vs. sensitization for others. Our results provide novel insights into the relative role of different classes of kinases in MM; the similarities and potential differences in the impact of pharmacological inhibition vs. genomic perturbation of these kinases. These integrated functional genomic and pharmacological studies of the kinome provide a framework for the potential development of inhibitors against previously understudied or underappreciated kinases; and the development of molecular or functional genomic assays that may potentially guide future efforts towards individualized administration of kinase inhibitors in MM. DisclosuresMitsiades:TEVA: Research Funding; Novartis: Research Funding; Janssen/Johnson & Johnson: Research Funding; Ono: Research Funding; Abbvie: Research Funding; Takeda: Other: Employment of family member.

Cardiac Safety of Kinase Inhibitors - Improving Understanding and Prediction of Liabilities in Drug Discovery Using Human Stem Cell-Derived Models.

Many small molecule kinase inhibitors (SMKIs) used to fight cancer have been associated with cardiotoxicity in the clinic. Therefore, preventing their failure in clinical development is a priority for preclinical discovery. Our study focused on the integration and concurrent measurement of ATP, apoptosis dynamics and functional cardiac indexes in human stem cell-derived cardiomyocytes (hSC-CMs) to provide further insights into molecular determinants of compromised cardiac function. Ten out of the fourteen tested SMKIs resulted in a biologically relevant decrease in either beating rate or base impedance (cell number index), illustrating cardiotoxicity as one of the major safety liabilities of SMKIs, in particular of those involved in the PI3K–AKT pathway. Pearson's correlation analysis indicated a good correlation between the different read-outs of functional importance. Therefore, measurement of ATP concentrations and apoptosis in vitro could provide important insight into mechanisms of cardiotoxicity. Detailed investigation of the cellular signals facilitated multi-parameter evaluation allowing integrative assessment of cardiomyocyte behavior. The resulting correlation can be used as a tool to highlight changes in cardiac function and potentially to categorize drugs based on their mechanisms of action.

Vascular Impact of Cancer Therapies: The Case of BTK (Bruton Tyrosine Kinase) Inhibitors.

Novel targeted cancer therapies have revolutionized oncology therapies, but these treatments can have cardiovascular complications, which include heterogeneous cardiac, metabolic, and vascular sequelae. Vascular side effects have emerged as important considerations in both cancer patients undergoing active treatment and cancer survivors. Here, we provide an overview of vascular effects of cancer therapies, focusing on small-molecule kinase inhibitors and specifically inhibitors of BTK (Bruton tyrosine kinase), which have revolutionized treatment and prognosis for B-cell malignancies. Cardiovascular side effects of BTK inhibitors include atrial fibrillation, increased risk of bleeding, and hypertension, with the former 2 especially providing a treatment challenge for the clinician. Cardiovascular complications of small-molecule kinase inhibitors can occur through either on-target (targeting intended target kinase) or off-target kinase inhibition. We will review these concepts and focus on the case of BTK inhibitors, highlight the emerging data suggesting an off-target effect that may provide insights into development of arrhythmias, specifically atrial fibrillation. We believe that cardiac and vascular sequelae of novel targeted cancer therapies can provide insights into human cardiovascular biology.

Bioreactor Suspension Culture: Differentiation and Production of Cardiomyocyte Spheroids From Human Induced Pluripotent Stem Cells.

Human induced-pluripotent stem cells (hiPSCs) can be efficiently differentiated into cardiomyocytes (hiPSC-CMs) via the GiWi method, which uses small-molecule inhibitors of glycogen synthase kinase (GSK) and tankyrase to first activate and then suppress Wnt signaling. However, this method is typically conducted in 6-well culture plates with two-dimensional (2D) cell sheets, and consequently, cannot be easily scaled to produce the large numbers of hiPSC-CMs needed for clinical applications. Cell suspensions are more suitable than 2D systems for commercial biomanufacturing, and suspended hiPSCs form free-floating aggregates (i.e., spheroids) that can also be differentiated into hiPSC-CMs. Here, we introduce a protocol for differentiating suspensions of hiPSC spheroids into cardiomyocytes that is based on the GiWi method. After optimization based on cardiac troponin T staining, the purity of hiPSC-CMs differentiated via our novel protocol exceeded 98% with yields of about 1.5 million hiPSC-CMs/mL and less between-batch purity variability than hiPSC-CMs produced in 2D cultures; furthermore, the culture volume could be increased ∼10-fold to 30 mL with no need for re-optimization, which suggests that this method can serve as a framework for large-scale hiPSC-CM production.

Alterations in the RTK/Ras/PI3K/AKT pathway serve as potential biomarkers for immunotherapy outcome of diffuse gliomas

Background: Diffuse gliomas are the most common malignant brain tumors, and immune checkpoint inhibitors have limited therapeutic effects against this cancer. Three oncogenic pathways are altered in diffuse gliomas: the RTK/Ras/PI3K/AKT signaling, TP53, and RB pathways. Although these pathways may affect the tumor immune microenvironment, their association with immunotherapy biomarkers remains unclear.Methods: We used copy number variation and mutation data to stratify patients with specific oncogenic signaling alterations, and evaluated their correlation with predictive immunotherapy biomarkers, including tumor mutation burden (TMB), immune cytolytic activity (CYT), tumor purity, and tumor-infiltrating CD8+ T cells. Immune checkpoint expression and interferon-γ signaling activity were also compared in these samples.Results: We identified differentially expressed genes in three distinct oncogenic pathways. Gene ontology analysis of these genes revealed the involvement of RTK/Ras/PI3K/AKT-associated genes in immune and inflammatory responses. Moreover, significantly elevated TMB, CYT, and numbers of CD8+ T cells and decreased tumor purity were correlated with altered RTK/Ras/PI3K/AKT signaling. Single cell sequencing also confirmed that this tumor subgroup had increased immune checkpoint expression and interferon-γ signaling activity. Immune phenotyping based on the presence of CD274 and TMB or CD274 and CD8 T+ cells indicated that tumors with altered RTK/Ras/PI3K/AKT pathways represent a beneficial subtype and are associated with improved survival.Conclusion: Altered RTK/Ras/PI3K/AKT signaling and immunotherapy biomarkers are strongly correlated in gliomas. Gliomas with altered expression of RTK/Ras/PI3K/AKT pathway components may be sensitive to immunotherapy. A combination of small-molecule kinase inhibitors and immunotherapy is proposed for this subgroup of tumors.

Analysis of the metabolomic profile in serum of irradiated nonhuman primates treated with Ex-Rad, a radiation countermeasure

To date, the United States Food and Drug Administration (FDA) has approved four drugs to mitigate hematopoietic acute radiation syndrome and all four are repurposed radiomitigators. There are several additional drug candidates currently under evaluation that may also be helpful for use during a widespread emergency. One possible candidate is Ex-Rad, also known as ON01210, a chlorobenzyl sulfone derivative (organosulfur compound), which is a novel, small-molecule kinase inhibitor with demonstrated efficacy in the murine model. In this study, we have evaluated the metabolomic and lipidomic profiles in serum samples of nonhuman primates (NHPs) treated with Ex-Rad after exposure to ionizing radiation. Two different dose administration schedules (Ex-Rad I administered 24 and 36 h post-irradiation, and Ex-Rad II administered 48 and 60 h post-irradiation), were used and evaluated using a global molecular profiling approach. We observed alterations in biochemical pathways relating to inflammation and oxidative stress after radiation exposure that were alleviated in animals that received Ex-Rad I or Ex-Rad II. The results from this study lend credence to the possible radiomitigative effects of this drug possibly via a dampening of metabolism-based tissue injury, thus aiding in recovery of vital, radiation-injured organ systems.

Liver Toxicity Observed With Lorlatinib When Combined With Strong CYP3A Inducers: Evaluation of Cynomolgus Monkey as a Nonclinical Model for Assessing the Mechanism of Combinational Toxicity.

Lorlatinib is a potent small-molecule anaplastic lymphoma kinase inhibitor approved for the treatment of patients with nonsmall cell lung cancer. In a drug-drug interaction study in healthy human participants, liver enzyme elevations were observed when a single 100 mg dose of lorlatinib was administered after multiple doses of rifampin, a strong cytochrome P450 (CYP) 3A inducer and a pregnane X receptor (PXR) agonist. A series of in vitro and in vivo studies were conducted to evaluate potential mechanisms for the observed clinical toxicity. To investigate the involvement of CYP3A and/or PXR in the observed liver toxicity, studies were conducted in cynomolgus monkeys administered lorlatinib alone or with coadministration of multiple doses of known CYP3A inducers that are predominantly PXR agonists (rifampin, St. John's wort) or predominantly constitutive androstane receptor agonists (carbamazepine, phenytoin) and a net CYP3A inhibitory PXR agonist (ritonavir). Results from the investigative studies identified cynomolgus monkeys as a pharmacologically relevant nonclinical model, which recapitulated the elevated liver function test results observed in humans. Furthermore, liver toxicity was only observed in this model when lorlatinib was coadministered with strong CYP3A inducers, and the effects were not restricted to, or exclusively dependent upon, a PXR activation mechanism. These results generated mechanistic insights on the liver enzyme elevations observed in the clinical drug-drug interaction study and provided guidance on appropriate product safety label for lorlatinib.

Phase II trial of surufatinib plus toripalimab for disease progression after first-line chemotherapy with platinum and fluoropyrimidine in advanced gastric or gastroesophageal junction adenocarcinoma.

e16040 Background: Surufatinib is a novel small-molecule kinase inhibitor targeting VEGFRs, FGFR and CSF-1R, simultaneous targeting of angiogenesis through VEGFRs/FGFR1 and modulating tumor immune microenvironment through CSF-1R may be a uniquely potent strategy to enhance antitumor activity. Toripalimab is a monoclonal humanized IgG4 PD-1 antibody. Encouraging efficacy of surufatinib plus toripalimab treating patients with advanced solid tumors was reported at 2020 AACR. This is an ongoing, multicenter, open-label, single-arm, phase II study to evaluate the efficacy and safety of surufatinib in combination with toripalimab in various solid tumors. Here we report the results of patients with advanced gastric or gastroesophageal junction (GEJ) adenocarcinoma. Methods: Patients with histologically confirmed gastric or GEJ adenocarcinoma who have failed first-line of systemic chemotherapy were enrolled. Surufatinib 250 mg once a day (QD) will be orally administrated and toripalimab 240 mg will be intravenously administered every 3 weeks. Primary endpoint was the objective response rate (ORR) per RECIST v1.1. Results: As of Dec 31, 2020, a total of 21 gastric or GEJ adenocarcinoma patients were enrolled. The median age was 58 years old, and 81% of the patients were male. Median duration of treatment was 3 months (surufatinib, 3 months; toripalimab, 3 months). Among 15 patients with at least one post-baseline efficacy evaluation, 2 patients achieved confirmed partial response (PR), with 3 additional unconfirmed PR. And there were 6 in stable disease (SD), 3 in progressive disease (PD) and one not evaluable per RECIST v1.1. There were 5 in PR, 7 in SD and 2 in PD per irRECIST, respectively. The confirmed and unconfirmed ORR were 13.3% (95% CI: 1.7%-40.5%) and 33.3% (95% CI: 11.8%-61.6%), respectively. The disease control rate (DCR) was 73.3% (95% CI: 44.9%-92.2%) per RECIST v1.1. Median PFS was 3.71 months (95% CI: 1.41-unknown). 14.3% (3/21) of patients had treatment-related adverse events (TRAEs) of ≥ Grade 3. The most common TRAEs of ≥ Grade 3 were herpes zoster (4.8%), lymphopenia (4.8%), lymphocyte count decreased (4.8%), white blood cell count decreased (4.8%), liver injury (4.8%) and anaemia (4.8%). 4.8% (1/21) of patients had serious TRAEs. One patient died due to unknown reasons. Conclusions: Surufatinib plus toripalimab appeared to show encouraging activity in advanced gastric or GEJ adenocarcinoma with manageable safety profile. Such combination could be a promising strategy for advanced gastric or GEJ adenocarcinoma in the future. Clinical trial information: NCT04169672.

Kinase drug discovery 20 years after imatinib: progress and future directions.

Protein kinases regulate nearly all aspects of cell life, and alterations in their expression, or mutations in their genes, cause cancer and other diseases. Here, we review the remarkable progress made over the past 20 years in improving the potency and specificity of small-molecule inhibitors of protein and lipid kinases, resulting in the approval of more than 70 new drugs since imatinib was approved in 2001. These compounds have had a significant impact on the way in which we now treat cancers and non-cancerous conditions. We discuss how the challenge of drug resistance to kinase inhibitors is being met and the future of kinase drug discovery.

Apatinib suppresses lung cancer stem-like cells by complex interplay between \u03b2-catenin signaling and mitochondrial ROS accumulation

The abnormal activation of Wnt/β-catenin signaling plays a critical role in the development of lung cancer, which is also important in the generation and maintenance of lung cancer stem cell (CSC). CSCs have unique capabilities to resist anticancer therapy, seed recurrent tumors, and disseminate to and colonize distant tissues. Apatinib, a small-molecule VEGFR2-tyrosine kinase inhibitor, shows highly efficient antitumor activity in heavily treated, chemoresistant, and metastatic lung cancer. We speculated that inhibition of Wnt/β-catenin signaling and targeting lung CSCs could be one of the anti-tumor mechanisms of apatinib. In the present study we demonstrated that apatinib repressed lung CSC-like traits by hindering sphere formation ability, lung CSC-related marker expression and decreasing chemoresistance derived stemness. Mechanistically, apatinib exerted its anti-CSC effects by inhibiting β-catenin and its downstream targets. Moreover, apatinib induced the production of reactive oxyen species (ROS), which participated in the inhibitory effects of apatinib on lung CSCs. It was found that β-catenin regulated apatinib-induced production of ROS. Inhibition or promotion of ROS production with N-acetyl-L-cysteine or H2O2 not only upregulated or downregulated β-catenin expression, but also prevented or promoted DNA damage, rescued or impeded sphere formation, respectively. Collectively, our findings reveal that apatinib directly inhibits β-catenin signaling and promotes ROS generation to suppress lung CSC-like characteristics. A clearer understanding of the anti-cancer mechanisms of apatinib is required for its better application in combating advanced and refractory/recurrent lung cancer when combined with conventional chemotherapy.

Phosphorylation, Mg-ADP, and Inhibitors Differentially Shape the Conformational Dynamics of the A-Loop of Aurora-A.

The conformational state of the activation loop (A-loop) is pivotal for the activity of most protein kinases. Hence, the characterization of the conformational dynamics of the A-loop is important to increase our understanding of the molecular processes related to diseases and to support the discovery of small molecule kinase inhibitors. Here, we carry out a combination of molecular dynamics (MD) and essential dynamics (ED) analyses to fully map the effects of phosphorylation, ADP, and conformation disrupting (CD) inhibitors (i.e., CD532 and MLN8054) on the dynamics of the A-loop of Aurora-A. MD revealed that the stability of the A-loop in an open conformation is enhanced by single phospho-Thr-288, while paradoxically, the presence of a second phosphorylation at Thr-287 decreases such stability and renders the A-loop more fluctuant in time and space. Moreover, we found that this post-translational modification has a significant effect on the direction of the A-loop motions. ED analysis suggests that the presence of the phosphate moiety induces the dynamics of Aurora-A to sample two distinct energy minima, instead of a single large minimum, as in unphosphorylated Aurora-A states. This observation indicates that the conformational distributions of Aurora-A with both single and double phospho-threonine modifications are remarkably different from the unphosphorylated state. In the closed states, binding of CD532 and MLN8054 inhibitors has the effect of increasing the distance of the N- and C-lobes of the kinase domain of Aurora-A, and the angle analysis between those two lobes during MD simulations showed that the N- and C-lobes are kept more open in presence of CD532, compared to MLN8054. As the A-loop is a common feature of Aurora protein kinases, our studies provide a general description of the conformational dynamics of this structure upon phosphorylation and different ligands binding.

JNK signaling as a target for anticancer therapy.

The JNKs are members of mitogen-activated protein kinases (MAPK) which regulate many physiological processes including inflammatory responses, macrophages, cell proliferation, differentiation, survival, and death. It is increasingly clear that the continuous activation of JNKs has a role in cancer development and progression. Therefore, JNKs represent attractive oncogenic targets for cancer therapy using small molecule kinase inhibitors. Studies showed that the two major JNK proteins JNK1 and JNK2 have opposite functions in different types of cancers, which need more specification in the design of JNK inhibitors. Some of ATP- competitive and ATP non-competitive inhibitors have been developed and widely used in vitro, but this type of inhibitors lack selectivity and inhibits phosphorylation of all JNK substrates and may lead to cellular toxicity. In this review, we summarized and discussed the strategies of JNK binding inhibitors and the role of JNK signaling in the pathogenesis of different solid and hematological malignancies.

Screenning Bioactive Compounds from Allium sativum as HER2 Inhibitors Targeting Breast Cancer by Docking Methods

Screenning Bioactive Compounds from Allium sativum as HER2 Inhibitors Targeting Breast Cancer by Docking Methods

Efficacy and Safety of Tofacitinib in Ulcerative Colitis Based on Prior Tumor Necrosis Factor Inhibitor Failure Status

Tofacitinib is an oral, small-molecule Janus kinase inhibitor for the treatment of ulcerative colitis (UC). We summarize the efficacy and safety data of tofacitinib 5 or 10 mg twice daily in the UC clinical program, stratified by prior tumor necrosis factor inhibitor (TNFi) failure status. Efficacy was assessed in the pooled phase 3 OCTAVE Induction 1 and 2 studies (N= 1139), the phase 3 OCTAVE Sustain maintenance study (N= 593), and the dose-escalation subpopulation of the open-label, long-term extension OCTAVE Open study (N= 59). Safety was assessed in OCTAVE Sustain, the dose-escalation subpopulation, and the Overall Cohort, which included patients from OCTAVE Induction 1 and 2, OCTAVE Sustain, and OCTAVE Open (N= 1124; no prior TNFi failure N= 541; prior TNFi failure N= 583; phase 2 data were excluded when stratified by prior TNFi failure status). The dose-escalation subpopulation received tofacitinib 10 mg twice daily in OCTAVE Induction 1 and 2, tofacitinib 5 mg twice daily in OCTAVE Sustain, and tofacitinib 10 mg twice daily in OCTAVE Open. Tofacitinib had greater efficacy than placebo, regardless of prior TNFi failure status. In OCTAVE Sustain and the Overall Cohort, herpes zoster [HZ] (nonserious and serious) rates were numerically higher in tofacitinib-treated patients with vs without prior TNFi failure. Dose escalation to tofacitinib 10 mg twice daily generally recaptured clinical response for most patients. HZ (nonserious and serious) rates were numerically higher in the dose-escalation subpopulation vs the Overall Cohort. Tofacitinib was efficacious in patients with UC regardless of prior TNFi failure status. HZ (nonserious and serious) rates were numerically higher in patients who had previously failed TNFi. ClinicalTrials.gov: A3921063 (NCT00787202); OCTAVE Induction 1 (NCT01465763); OCTAVE Induction 2 (NCT01458951); OCTAVE Sustain (NCT01458574); and OCTAVE Open (NCT01470612).

Structural insights of oxindole based kinase inhibitors as anticancer agents: Recent advances.

Small-molecule kinase inhibitors are being continuously explored as new anticancer therapeutics. Kinases are the phosphorylating enzymes which regulate numerous cellular functions such as proliferation, differentiation, migration, metabolism, and angiogenesis by activating several signalling pathways. Kinases have also been frequently found to be deregulated and overexpressed in cancerous tissues. Therefore, modulating the kinase activity by employing small molecules has emerged as a strategic approach for cancer treatment. On the other hand, oxindole motifs have surfaced as privileged scaffolds with significant multi-kinase inhibitory activity. The present review summarises recent advances in the development of oxindole based kinase inhibitors. The role of distinguished structural frameworks of oxindoles, such as 3-alkenyl oxindoles, spirooxindoles, 3-iminooxindoles and similar hydrazone derivatives have been described based on their kinase inhibition potential. Furthermore, the design strategies, mechanism of actions, structure activity relationships (SARs) and their mode of interaction with target protein have been critically highlighted.

Identification of Small-Molecule Inhibitors of Human Inositol Hexakisphosphate Kinases by High-Throughput Screening.

Inositol hexakisphosphate kinases (IP6Ks) catalyze pyrophosphorylation of inositol hexakisphosphate (IP6) into inositol 5-diphospho-1,2,3,4,6-pentakisphosphate (IP7), which is involved in numerous areas of cell physiology including glucose homeostasis, blood coagulation, and neurological development. Inhibition of IP6Ks may be effective for the treatment of Type II diabetes, obesity, metabolic complications, thrombosis, and psychiatric disorders. We performed a high-throughput screen (HTS) of 158 410 compounds for IP6K1 inhibitors using a previously developed ADP-Glo Max assay. Of these, 1206 compounds were found to inhibit IP6K1 kinase activity by more than 25%, representing a 0.8% hit rate. Structural clustering analysis of HTS-active compounds, which were confirmed in the dose-response testing using the same kinase assay, revealed diverse clusters that were feasible for future structure-activity relationship (SAR) optimization to potent IP6K inhibitors. Medicinal chemistry SAR efforts in three chemical series identified potent IP6K1 inhibitors which were further validated in an orthogonal LC-MS IP7 analysis. The effects of IP6K1 inhibitors on cellular IP7 levels were further confirmed and were found to correlate with cellular IP6K1 binding measured by a high-throughput cellular thermal shift assay (CETSA).

Sulfasalazine synergistically enhances the inhibitory effects of imatinib against hepatocellular carcinoma (HCC) cells by targeting NFκB, BCR/ABL, and PI3K/AKT signaling pathway-related proteins.

Hepatocellular carcinoma (HCC) is the third leading cause of cancer-related fatalities worldwide. Identification of second-line therapies for patients with progressive HCC is urgently required as the use of sorafenib and/or regorafenib remains unsatisfactory. Imatinib, a small-molecule kinase inhibitor, is used to treat certain types of cancer, and nuclear factor κB (NFκB) is a positive regulator of cancer cell expansion. The combined use of tyrosine kinase and NFκB inhibitors may have potential for treating HCC. The aim of this work was to assess the potential anticarcinogenic effects of imatinib and sulfasalazine alone or in combination on the human HCC cell lines HEPG2 and Huh-7. Both drugs were shown to affect the phosphoinositide 3-kinase/protein kinase B, phosphorylated signal transducer and activator of translation (p-STAT-3), breakpoint cluster region protein/Abelson proto-oncogene and NFκB pathways. At the transcriptional level, imatinib and sulfasalazine were found to synergistically down-regulate c-MET gene expression. When compared with the activities of either medication alone, combined use of imatinib and sulfasalazine enhanced inhibition of HCC cell proliferation and extended induction of apoptosis. In summary, the presented data suggest that sulfasalazine synergistically potentiates the antitumor effects of imatinib.

Feasibility of Extrapolating Randomly Taken Plasma Samples to Trough Levels for Therapeutic Drug Monitoring Purposes of Small Molecule Kinase Inhibitors.

Small molecule kinase inhibitors (SMKIs) are widely used in oncology. Therapeutic drug monitoring (TDM) for SMKIs could reduce underexposure or overexposure. However, logistical issues such as timing of blood withdrawals hamper its implementation into clinical practice. Extrapolating a random concentration to a trough concentration using the elimination half-life could be a simple and easy way to overcome this problem. In our study plasma concentrations observed during 24 h blood sampling were used for extrapolation to trough levels. The objective was to demonstrate that extrapolation of randomly taken blood samples will lead to equivalent estimated trough samples compared to measured Cmin values. In total 2241 blood samples were analyzed. The estimated Ctrough levels of afatinib and sunitinib fulfilled the equivalence criteria if the samples were drawn after Tmax. The calculated Ctrough levels of erlotinib, imatinib and sorafenib met the equivalence criteria if they were taken, respectively, 12 h, 3 h and 10 h after drug intake. For regorafenib extrapolation was not feasible. In conclusion, extrapolation of randomly taken drug concentrations to a trough concentration using the mean elimination half-life is feasible for multiple SMKIs. Therefore, this simple method could positively contribute to the implementation of TDM in oncology.

Targeting EphA2 suppresses hepatocellular carcinoma initiation and progression by dual inhibition of JAK1/STAT3 and AKT signaling

Hepatocellular carcinoma (HCC) remains one of the deadliest malignancies worldwide. One major obstacle to treatment is a lack of effective molecular-targeted therapies. In this study, we find that EphA2 expression and signaling are enriched in human HCC and associated with poor prognosis. Loss of EphA2 suppresses the initiation and growth of HCC both invitro and invivo. Furthermore, CRISPR/CAS9-mediated EphA2 inhibition significantly delays tumor development in a genetically engineered murine model of HCC. Mechanistically, we discover that targeting EphA2 suppresses both AKT and JAK1/STAT3 signaling, two separate oncogenic pathways in HCC. We also identify a small molecule kinase inhibitor of EphA2 that suppresses tumor progression in a murine HCC model. Together, our results suggest EphA2 as a promising therapeutic target for HCC.