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Ruxolitinib (RUX) is a kinase inhibitor used in the treatment of various medical conditions and its mechanism of action involves suppression of the immune system. While beneficial in treatment of polycythemia vera, myelofibrosis and other indications, it can also increase a patient’s susceptibility to various infections, including bacterial, viral and fungal. We present a case of a patient being treated with RUX who presented with a disseminated fungal infection. This case emphasises the need for vigilance of endemic fungal infections in individuals who are on RUX therapy.

After injury to the central nervous system (CNS), both neuron-intrinsic limitations on regenerative responses and inhibitory factors in the injured CNS environment restrict regenerative axon growth. Instances of successful axon regrowth offer opportunities to identify features that differentiate these situations from that of the normal adult CNS. One such opportunity is provided by the kinase inhibitor RO48, which dramatically enhances neurite outgrowth of neurons in vitro and substantially increased contralateral sprouting of corticospinal tract neurons when infused intraventricularly following unilateral pyramidotomy. The authors present here a transcriptomic deconvolution of RO48-associated axon growth, with the goal of identifying transcriptional regulators associated with axon growth in the CNS. Through the use of RNA sequencing (RNA-seq) and transcription factor binding site enrichment analysis, the authors identified a list of transcription factors putatively driving differential gene expression during RO48-induced neurite outgrowth of rat hippocampal neurons in vitro. The 82 transcription factor motifs identified in this way included some with known association to axon growth regulation, such as Jun, Klf4, Myc, Atf4, Stat3, and Nfatc2, and many with no known association to axon growth. A phenotypic loss-of-function screen was carried out to evaluate these transcription factors for their roles in neurite outgrowth; this screen identified several potential outgrowth regulators. Subsequent validation suggests that the Forkhead box (Fox) family transcription factor Foxp2 restricts neurite outgrowth, while FoxO subfamily members Foxo1 and Foxo3a promote neurite outgrowth. The authors' combined transcriptomic-phenotypic screening strategy therefore allowed identification of novel transcriptional regulators of neurite outgrowth downstream of a multitarget kinase inhibitor.

While considerable success has been achieved with treating BRAF-V600E mutant tumors in several organ systems, tumors expressing non-V600E BRAF mutations remain a significant clinical challenge. Such atypical BRAF mutations are classified based on their kinase activity, RAS-dependence and their requirement for dimerization to function. We identified an unusually large in-frame deletion in a melanoma patient, encompassing codons 600-618 in the kinase domain. This patient experienced rapid disease progression when treated with dual BRAF/MEK inhibition. To determine whether and how such a large in-frame BRAF deletion might be activating, we ectopically expressed it in HEK293 cells and monitored BRAF pathway activation and response to BRAF and MEK inhibitors. We demonstrate that this mutation results in a kinase-deficient BRAF mutant which, nevertheless, activates MEK/ERK signaling in a dimerization-dependent manner, placing this mutation among the class III BRAF mutants.

The recent emergence of lyn kinase as a driver of aggressive behaviour in triple-negative breast cancer (TNBC) remains a major concern posing a burden for people living with breast cancer and drug development. The binding of UM-164 to lyn protein has been noted to impact the conformational dynamics required for drug fitness. Herein, we provide the first account of the molecular impact of an experimental drug, UM-164 binding on lyn protein using various computational approaches including molecular docking and molecular dynamics simulation. These computational modelling methods enabled us to analyse parameters, for example principal component analysis (PCA), dynamics cross-correlation matrices (DCCM) analysis, hydrogen bond occupancy, thermodynamics calculation and ligand–residue interaction. Findings from these analyses revealed that UM-164 exhibited a higher binding affinity of −9.9 kcal mol−1 with lyn protein than Dasatinib, with a binding affinity of −8.3 kcal mol−1 on docking. It was observed that the binding of UM-164 to lyn protein decreases the capacity of its loop to fluctuate, influences the ligand optimum orientation on the conformational space of lyn protein, and increases the hydrogen bond formation in the lyn-UM-164 system. Also, an increase in drug binding energy of UM-164 was recorded with increasing residue correlation in the lyn-UM-164 system. It is quite informative to note that Met85 was a key stabilising factor in the binding of UM-164 to lyn protein. These findings can provide important insights that will potentially serve as a baseline in the design of novel lyn inhibitors. It could also stimulate further research into multidimensional approaches required to curb the influence of lyn protein in TNBC.

KRAS is one of the most important proto-oncogenes. Its mutations occur in almost all tumor types, and KRAS mutant cancer is still lack of effective therapy. Prenyl-binding protein phosphodiesterase-δ (PDEδ) is required for the plasma membrane association and subsequent activation of KRAS oncogenic signaling. Recently, targeting PDEδ has provided new promise for KRAS mutant tumors. However, the therapeutic potential of PDEδ inhibition remains obscure. In this study, we explored how PDEδ inhibition was responded in KRAS mutant cancer cells, and identified KRAS mutant subset responsive to PDEδ inhibition. We first performed siRNA screen of KRAS growth dependency of a small panel of human cancer lines, and identified a subset of KRAS mutant cancer cells that were highly dependent on KRAS signaling. Among these cells, only a fraction of KRAS-dependent cells responded to PDEδ depletion, though KRAS plasma membrane association was effectively impaired. We revealed that the persistent RAF/MEK/ERK signaling seemed responsible for the lack of response to PDEδ depletion. A kinase array further identified that the feedback activation of EPH receptor A2 (EPHA2) accounted for the compensatory activation of RAF/MEK/ERK signaling in these cells. Simultaneous inhibition of EPHA2 and PDEδ led to the growth inhibition of KRAS mutant cancer cells. Together, this study gains a better understanding of PDEδ-targeted therapeutic strategy and suggests the combined inhibition of EPHA2 and PDEδ as a potential therapy for KRAS mutant cancer.

Introduction: Ataxia Telangiectasia (AT) is an autosomal recessive disorder due to mutations in the ATM gene (11q22.3), which encodes a kinase, which initiates and propagates the cellular response ...

Kinases are essential regulators of a variety of cellular signaling processes, including neurite formation – a foundational step in neurodevelopment. Aberrant axonal sprouting and failed regeneration of injured axons are associated with conditions like traumatic injury, neurodegenerative disease, and seizures. Investigating the mechanisms underlying neurite formation will allow for identification of potential therapeutics. We used a kinase inhibitor library to screen 493 kinase inhibitors and observed that 45% impacted neuritogenesis in Neuro2a (N-2a) cells. Based on the screening, we further investigated the roles of Aurora kinases A, B, and C and Nuak kinases 1 and 2. The roles of Aurora and Nuak kinases have not been thoroughly studied in the nervous system. Inhibition or overexpression of Aurora and Nuak kinases in primary cortical neurons resulted in various neuromorphological defects, with Aurora A regulating neurite initiation, Aurora B and C regulating neurite initiation and elongation, all Aurora kinases regulating arborization, and all Nuak kinases regulating neurite initiation and elongation and arborization. Our high-throughput screening and analysis of Aurora and Nuak kinases revealed their functions and may contribute to the identification of therapeutics.

Mass spectrometry enables high-throughput screening of phosphoproteins across a broad range of biological contexts. When complemented by computational algorithms, phospho-proteomic data allows the inference of kinase activity, facilitating the identification of dysregulated kinases in various diseases including cancer, Alzheimer’s disease and Parkinson’s disease. To enhance the reliability of kinase activity inference, we present a network-based framework, RoKAI, that integrates various sources of functional information to capture coordinated changes in signaling. Through computational experiments, we show that phosphorylation of sites in the functional neighborhood of a kinase are significantly predictive of its activity. The incorporation of this knowledge in RoKAI consistently enhances the accuracy of kinase activity inference methods while making them more robust to missing annotations and quantifications. This enables the identification of understudied kinases and will likely lead to the development of novel kinase inhibitors for targeted therapy of many diseases. RoKAI is available as web-based tool at http://rokai.io., Kinases drive fundamental changes in cell state, but predicting kinase activity based on substrate-level changes can be challenging. Here the authors introduce a computational framework that utilizes similarities between substrates to robustly infer kinase activity.

Kinase inhibitors are promising drugs to stabilize the endothelial barrier following inflammatory damage. However, our limited knowledge of how kinase signaling activates barrier-restorative pathways and the complexity of multi-target drugs have hindered drug discovery and repurposing efforts. Here, we apply a kinase regression approach that exploits drug polypharmacology to investigate endothelial barrier regulation. A screen of 28 kinase inhibitors identified multiple inhibitors that promote endothelial barrier integrity and revealed divergent barrier phenotypes for BCR-ABL drugs. Target deconvolution predicted 50 barrier-regulating kinases from diverse kinase families. Using gene knockdowns, we identified kinases with a role in endothelial barrier regulation and dissected different mechanisms of action of barrier-protective kinase inhibitors. These results demonstrate the importance of polypharmacology in the endothelial barrier phenotype of kinase inhibitors and provide promising new leads for barrier-strengthening therapies.

Cobimetinib is a kinase inhibitor indicated for use in combination with vemurafenib for treatment of unresectable/metastatic melanoma with specific BRAF mutations. Cobimetinib is extensively metabolized in liver; thus, patients with hepatic impairment (HI) might have increased cobimetinib exposure. In this study, we investigated the impact of HI on the pharmacokinetics (PK) and safety of cobimetinib. Subjects with normal hepatic function and mild to severe HI were enrolled. All subjects received a single oral dose of 10 mg cobimetinib, and serial blood samples were collected at specified times. Cobimetinib PK in subjects with mild and moderate HI was similar to that in those with normal liver function. However, subjects with severe HI, on average, showed ∼30% lower total AUC0‐∞ and ∼2‐fold higher unbound AUC0‐∞ compared with those with normal hepatic function. These exposure differences can be explained by lower albumin levels observed in subjects with severe HI, the strong correlation between albumin level and the unbound fraction and the general PK variability of cobimetinib. In addition, previous studies with cobimetinib showed a lack of an exposure‐response relationship for efficacy and safety. Therefore, collectively, our results suggest that the starting dose for patients with hepatic impairment can be the same as that for those with normal hepatic function.

How living systems break symmetry in an organized manner is a fundamental question in biology. In wild-type Caenorhabditis elegans zygotes, symmetry breaking during anterior-posterior axis specification is guided by centrosomes, resulting in anterior-directed cortical flows and a single posterior PAR-2 domain. We uncover that C. elegans zygotes depleted of the Aurora A kinase AIR-1 or lacking centrosomes entirely usually establish two posterior PAR-2 domains, one at each pole. We demonstrate that AIR-1 prevents symmetry breaking early in the cell cycle, whereas centrosomal AIR-1 instructs polarity initiation thereafter. Using triangular microfabricated chambers, we establish that bipolarity of air-1(RNAi) embryos occurs effectively in a cell-shape and curvature-dependent manner. Furthermore, we develop an integrated physical description of symmetry breaking, wherein local PAR-2-dependent weakening of the actin cortex, together with mutual inhibition of anterior and posterior PAR proteins, provides a mechanism for spontaneous symmetry breaking without centrosomes.

9071 Background: BRG is a kinase inhibitor approved for the treatment of patients (pts) with ALK+ metastatic NSCLC; specific details for BRG use vary by indication and country. We report long-term efficacy and safety results of the Phase 1/2 and Phase 2 (ALTA) trials of BRG. Methods: The Phase 1/2 study was a single-arm, open-label trial (NCT01449461) of BRG 30–300 mg/d in pts with advanced malignancies. ALTA (NCT02094573) randomized pts with CRZ-refractory ALK+ NSCLC to receive BRG at 90 mg qd (arm A) or 180 mg qd with 7-d lead-in at 90 mg (arm B). For the Phase 1/2 study, investigator assessments of confirmed objective response rate (cORR; RECIST v1.1), duration of response (DoR), progression-free survival (PFS), overall survival (OS), and safety in pts with ALK+ NSCLC are reported. The primary endpoint of ALTA was cORR per investigator; secondary endpoints included cORR per independent review committee (IRC), DoR, PFS, and OS. Results: In the Phase 1/2 study, 137 pts received BRG; of these, 79 pts had ALK+ NSCLC (71/79 had prior CRZ; 28/79 received 180 mg qd [7-d lead-in at 90 mg]; 14/79 received 90 mg qd). In ALTA, 222 pts with CRZ-refractory ALK+ NSCLC were randomized (n = 112/110, arm A/B). At the end of the Phase 1/2 study (Feb 18, 2020), with median 27.7 mo follow-up (̃67 mo after last pt enrolled), 4 pts remained on BRG. At the end of ALTA (Feb 27, 2020), with median 19.6/28.3 mo follow-up in arm A/B (̃53 mo after last pt enrolled), 10/17 pts in arm A/B were still on treatment. Table shows efficacy results from final analyses with long-term follow-up. In ALTA, the IRC-assessed intracranial cORR in pts with measurable baseline brain metastases was 50% (13/26) in arm A and 67% (12/18) in arm B; Kaplan-Meier (KM) estimated median intracranial DoR was 9.4 mo (95% CI, 3.7, not reached [NR]) in arm A and 16.6 mo (3.7, NR) in arm B. With long-term follow-up, no new safety signals were identified. Treatment-emergent adverse events led to dose interruption (Phase 1/2: 59%; ALTA arm A/B: 49%/61%), dose reduction (13%; 8%/33%), or discontinuation (10%; 4%/13%). Conclusions: BRG showed sustained long-term activity, PFS, and manageable safety in pts with CRZ-refractory ALK+ NSCLC. The 180 mg/d dose after 7-d lead-in at 90 mg/d led to numerically higher median PFS and OS. Final results are similar to those reported for other approved ALK tyrosine kinase inhibitors in this setting. Clinical trial information: NCT01449461, NCT02094573. [Table: see text]

Tuberous sclerosis complex (TSC) is a rare multi-system disorder, primary manifestations of which are benign tumors and lesions in various organs of the body, including the brain. TSC patients often suffer from epilepsy, mental retardation, and autism spectrum disorder (ASD). Therefore, TSC serves as a model of epilepsy, ASD, and tumorigenesis. TSC is caused by the lack of functional Tsc1-Tsc2 complex, which serves as a major cellular inhibitor of mammalian Target of Rapamycin Complex 1 (mTORC1). mTORC1 is a kinase controlling most of anabolic processes in eukaryotic cells. Consequently, mTORC1 inhibitors, such as rapamycin, serve as experimental or already approved drugs for several TSC symptoms. However, rapalogs, although quite effective, need to be administered chronically and likely for a lifetime, since therapy discontinuation results in tumor regrowth and epilepsy recurrence. Recent studies revealed that metabolism and excitability (in the case of neurons) of cells lacking Tsc1-Tsc2 complex are changed, and these features may potentially be used to treat some of TSC symptoms. In this review, we first provide basic facts about TSC and its molecular background, to next discuss the newest findings in TSC cell biology that can be used to improve existing therapies of TSC and other diseases linked to mTORC1 hyperactivation. © 2016 IUBMB Life, 68(12):955-962, 2016.

e23580 Background: Pexidartinib, a kinase inhibitor, is approved for treatment of adult patients with symptomatic tenosynovial giant cell tumor (TGCT) associated with severe morbidity or functional limitations and not amenable to improvement with surgery. Due to risk of serious and potentially fatal liver injury, pexidartinib is available via a Risk Evaluation and Mitigation Strategy (REMS) Program. A requirement of the REMS is to conduct a qualitative evaluation of stakeholder Knowledge, Attitudes, and Behavior (KAB) of risks via surveys. The objective of the qualitative evaluation is to review key risk message questions with respect to understanding, relevance, clarity and provide recommendations on alternative language, phrasing, and structure. Methods: Anonymized, one-on-one 45–60-min phone interviews with patients and HCPs were conducted by UBC. Patients ≥18 y, diagnosed with TGCT (prioritized) or metastasis/sarcoma of the connective tissue, with different levels of education and fluent reading/speaking English were included. To participate, HCPs were required to treat patients with TGCT (prioritized) or metastasis/sarcoma of the connective tissue, treat patients ≥75% of their time, and clearly read/speak English. Participants were required to complete an Interview Release Form (IRF) and confirm access to a computer/tablet. Participants had little/no familiarity with pexidartinib materials. All interviews followed a standard process, used a pre-scripted guide on general instructions, confidentiality, safety event reporting, rapport building and assessment of health literacy (patients only). Feedback regarding understanding, relevance, and clarity were used to recommend potential alternate language/phrasing. To receive compensation participants were required to execute/return the IRF. Results: Twelve patients were interviewed, majority 67% had TGCT; mean age 52 y; 58% female; 42% reported some college/associates degree. 12 HCPs were interviewed, 67% treated patients with TGCT; 100% male; mean years practicing 22; all spent 75% or more time seeing patients; primary specialty Orthopedics. Areas of confusion/misunderstanding were reported, and questions were then revised. Patient findings: complexity and wordiness; HCP findings: repetition/difficulty reading, and some terminology was not self-explanatory. Conclusions: Feedback from HCPs and patients was received to improve the key risk messages of the KAB. Qualitative research is recommended to improve comprehension and data quality collected.

Epub ahead of print; OBJECTIVE: GCN2 is a kinase which detects amino acid deficiency and is involved in the control of protein synthesis and energy metabolism. However, the role of hepatic GCN2 in the metabolic adaptations in response to the modulation of dietary protein has been seldom studied. METHODS: Wild-type (WT) and liver GCN2-deficient (KO) mice were fed either a normo-protein diet, a low-protein diet or a high-protein diet for 3 weeks. During this period, body weight, food intake and metabolic parameters were followed. RESULTS: In mice fed normo- and high protein diets, GCN2 pathway in the liver is not activated in WT mice leading to a similar metabolic profile with the one of KO mice. On the contrary, a low protein diet activates GCN2 in WT mice inducing FGF21 secretion. In turn, FGF21 maintains a high level of lipid oxidation leading to a different postprandial oxidation profile compared with KO mice. CONCLUSIONS: Hepatic GCN2 controls FGF21 secretion under a low protein diet, and modulates a whole-body postprandial oxidation profile.

This case demonstrates the essential contribution of the p110δ catalytic 21 domain in adaptive immunity function in a patient with expression of a kinase-dead p110δ mutant.

Purpose Axitinib (Inlyta, New York, NY) is a kinase inhibitor indicated for the treatment of advanced renal cell carcinoma after failure of one previous systemic therapy. A case of bilateral retinal hemorrhages and cotton wool spots associated with axitinib is reported. Methods A 62-year-old woman with a 4-year history of renal cell carcinoma with metastases was treated with axitinib at a maximum oral daily dose of 8 mg. Soon after beginning higher dose therapy, she developed blurred vision, floaters, and photopsias. Results Funduscopic examination of both eyes revealed cotton wool spots and retinal hemorrhages that improved with cessation of therapy. Conclusion Axitinib may be associated with microangiopathic retinal toxicity.

The largest study to date on the genetics of hip and knee osteoarthritis (OA) has yielded new associations with genes encoding a cytokine, a kinase and a transcriptional repressor, as well as genetic correlations with other diseases. Can these clues help to unravel details of the pathogenesis of OA?

Summary ATP-competitive kinase inhibitors often bind several kinases due to the high conservation of the ATP binding pocket. Through clustering analysis of a large kinome profiling dataset, we found a cluster of eight promiscuous kinases that on average bind more than five times more kinase inhibitors than the other 398 kinases in the dataset. To understand the structural basis of promiscuous inhibitor binding, we determined the co-crystal structure of the receptor tyrosine kinase DDR1 with the type I inhibitors dasatinib and VX-680. Surprisingly, we find that DDR1 binds these type I inhibitors in an inactive conformation typically reserved for type II inhibitors. Our computational and biochemical studies show that DDR1 is unusually stable in this inactive conformation, giving a mechanistic explanation for inhibitor promiscuity. This phenotypic clustering analysis provides a strategy to obtain functional insights not available by sequence comparison alone.

In the field of kinase inhibitors for applications in cancer research, tubulin is emerging as a targeted cellular protein that can significantly contribute to their activities. However, investigation of kinase inhibitors beyond the kinome is an area often neglected. Herein, we describe the results of pharmacological studies using drugs targeting kinases, tubulin or both. A key finding is that if cells are treated with a kinase inhibitor unintentionally targeting tubulin, their characteristic shape will diminish within a short timeframe. These changes in cell morphology are not seen when cells are treated with bona fide kinase inhibitors that do not directly target tubulin. Thus, early changes in cell morphology upon treatments are a strong indication that the inhibitor is directly targeting tubulin. Recognizing tubulin as a target of kinase inhibitors will build confidence in the future mechanistic studies using kinase inhibitors.

The majority of kinase inhibitors have been developed as ATP competitors to interact with a hinge region in ATP binding sites of kinases. 7-Azaindole has been found as an excellent hinge binding motif by making two hydrogen bonds with the kinase hinge region. Vemurafenib, a B-RAF kinase (serine-threonine kinase [STK]) inhibitor approved by the U.S. Food and Drug Administration (FDA) for the treatment of melanoma, was created from this simple 7-azaindole fragment by successful use of structure-based drug design techniques. The huge potential of 7-azaindole as a hinge-binding motif has encouraged many researchers to employ it as a kinase privileged fragment. This paper will review recent examples of 7-azaindole-based kinase inhibitors, and discusses their binding interactions with the kinase hinge regions.

The therapeutic effect of targeted kinase inhibitors can be significantly reduced by intrinsic or acquired resistance mutations that modulate the affinity of the drug for the kinase. In cancer, the majority of missense mutations are rare, making it difficult to predict their impact on inhibitor affinity. We examine the potential for alchemical free-energy calculations to predict how kinase mutations modulate inhibitor affinities to Abl, a major target in chronic myelogenous leukemia (CML). These calculations have useful accuracy in predicting resistance for eight FDA-approved kinase inhibitors across 144 clinically identified point mutations, with a root mean square error in binding free-energy changes of $$1.1_{0.9}^{1.3}$$ 1 . 1 0.9 1.3 kcal mol−1 (95% confidence interval) and correctly classifying mutations as resistant or susceptible with $$88_{82}^{93}$$ 8 8 82 93 % accuracy. This benchmark establishes the potential for physical modeling to collaboratively support the assessment and anticipation of patient mutations to affect drug potency in clinical applications.

Role of kinase inhibitors in various diseases is well established and discovery of imatinib opens up new paradigms in kinase inhibition. Furthermore, presence of heterocyclic moiety in a kinase inhibitor seems to be essential now. However, the potential of a single heterocyclic moiety was discussed in variety of reviews but a focus review considering the potential of different heterocyclic moieties is unavailable. Based on this, we classify prospective kinase inhibitors on the basis of number of heterocyclic moieties present and summarize the prospective kinase inhibitors. Finally, important key points, current challenges and future prospects of kinase inhibitors are also discussed.

International audience; Receptor interacting protein kinase 1 (RIPK1) represents a key molecule in cell death. Here, we discuss our recent data on RIPK1 in liver injury and hepatocellular carcinoma development and put these into relation to previous experimental findings to underpin that it exerts opposing kinase-dependent and kinase independent functions in liver cells.

3091 Background: Prexasertib inhibits CHK1, a kinase involved in DNA repair and replication. LY3023414 inhibits PI3K/mTOR signaling, implicated in the development of malignant disease. Prexasertib + LY3023414 has resulted in enhanced antitumor activity in triple negative breast cancer (TNBC) in vitro models. Methods: This Phase 1b study in patients (pts) with solid tumors assessed escalating doses of prexasertib (60-105 mg/m2 IV every 14 days [q14d]) and LY3023414 (100-200 mg orally twice daily [BID]). Dose escalation ceased once the maximum tolerated dose of each monotherapy was reached. An initial expansion cohort (Arm E) explored prexasertib 105 mg/m2 q14d + LY3023414 200 mg BID. Subsequent expansion cohorts evaluated prexasertib 105 mg/m2 q14d + LY3023414 150 mg BID in pts with solid tumors with PIK3CA mutations (Arm E2) or TNBC (Arm E3). Results: Fifty pts were enrolled (escalation: n = 13; Arm E: n = 9; Arm E2: n = 15; Arm E3: n = 13). No dose-limiting toxicities (DLTs) were observed during escalation however DLT-equivalent toxicities were observed in 2 pts in Arm E (anemia, neutropenia, thrombocytopenia, oral mucositis, abdominal pain, fatigue). Due to toxicity, a reduced dose of LY3023414 (150 mg BID) was assessed in Arm E2/E3. In the 28 patients treated in Arms E2/E3, common treatment-related adverse events (any grade; grade ≥3) were: leukopenia/neutropenia (82%; 79%), thrombocytopenia (46%; 36%), nausea (46%; 0%), stomatitis (39%, 4%), vomiting (36%; 0%), and anemia (29%; 18%). Febrile neutropenia was reported in 25% of pts. Dose reductions in Arm E2/E3 were common. In escalation, 2 pts achieved a partial response (PR) and 3 pts achieved stable disease (SD). In Arm E, 78% of pts achieved SD. Of the pts evaluable at the time of data transfer, PRs were achieved in 1 pt with an unknown primary (Arm E2) and 2 pts with TNBC (Arm E3). Each agent’s pharmacokinetic profile was consistent with prior monotherapy data. Conclusions: Prexasertib + LY3023414 showed preliminary efficacy in heavily pretreated pts with solid tumors but was associated with toxicity, suggesting supportive care may be required. Clinical trial information: NCT02124148.

e15607 Background: FGFR2 fusions are prevalent in 13-22% of iCCA and known oncogenic drivers. DZB is a kinase inhibitor with potent pan-FGFR activity. In a non-comparative Phase 2a study, DZB was administered to 29 pts with FGFR2-fusion positive advanced, inoperable iCCA, either as first-line (1L) (n = 2), 2L (n = 13), 3L (n = 10), 4L (n = 2) or 5L therapy (n = 2). The objective response rate (ORR) with DZB was 21%, disease-control rate (DCR) 83% and median PFS 5.7 months (Mazzaferro et al. 2018 BJC). Data from biliary tract cancer studies suggest decreasing treatment effects of chemotherapy with increasing lines of treatment. Here, we present a post-hoc analysis of outcomes of pts treated with DZB in 1L/2L (n = 15) compared to pts treated post-2L (n = 14). Methods: Pts received 300 mg DZB QD PO. Eligibility criteria included locally confirmed, positive testing of FGFR2 fusion expression (FISH or NGS), ECOG PS 0-1. Objective responses were determined using RECIST 1.1. Disease control rate was defined as CR, PR or SD. Results: The mean age of pts treated in 1L/2L was 66y and 55y in post-2L; 73% were females in 1L/2L and 50% in post-2L treatment; other demographic variables were balanced between groups (87% vs 86% of liver target lesions, median baseline lesion size of 97.5 mm vs 109.5 mm, ECOG PS0 was 60% vs 71%). Of 15 1L/2L group pts, 12 (80%) had prior platinum-based chemotherapy as compared to all 14 pts in the post-2L group. In the 1L/2L and post-2L groups, ORR was 20% and 21%, DCR was 80% and 86%, and a reduction in sum of the largest diameter of target lesions was observed in 60% and 64% of pts, respectively. Median PFS was 5.5 mo (95% CI, 1.9-11.9) and 6.2 mo (3.6-9.2) for the 1L/2L and post-2L groups, respectively. Types of drug-related adverse events were similar in 1L/2L and post-2L. Conclusions: Anti-tumor efficacy of DZB in iCCA patients measured either by ORR, DCR, tumor shrinkage or PFS was numerically similar irrespective of treatment line. These data suggest that DZB is an effective treatment option that can be applied early in the treatment continuum of iCCA patients or at later stages to offer anti-tumor efficacy and disease control. Clinical trial information: 01752920.

Cancer Acute erythroid leukemia (AEL) is an aggressive, poorly understood disease that has been difficult to distinguish from other blood cancers that are associated with a better prognosis. To determine if genomic information could improve diagnostic accuracy, Iacobucci et al. comprehensively analyzed 159 patients with AEL. Their study not only identified mutations and mutational patterns that were specific to AEL but also revealed that 45% of the patient samples had alterations in cell signaling pathways that could be therapeutically targeted. Of note was the discovery of activating mutations in NTRK1, a kinase for which there is a clinically approved pharmacological inhibitor. Treatment of a mouse model of AEL with this drug inhibited growth of leukemic cells. Nat. Genet. 51 , 694 (2019).

DYRK1B is a kinase over-expressed in certain cancer cells (including colon, ovarian, pancreatic, etc.). Recent publications have demonstrated inhibition of DYRK1B could be an attractive target for cancer therapy. From a data-mining effort, the team has discovered analogues of pyrido[2,3-d]pyrimidines as potent enantio-selective inhibitors of DYRK1B. Cells treated with a tool compound from this series showed the same cellular effects as down regulation of DYRK1B with siRNA. Such effects are consistent with the proposed mechanism of action. Progress of the SAR study is presented.

This week’s papers describe therapies for myeloid cancers and a kinase to inhibit in order to prevent pathogenic bone destruction.

The phosphorelay of Bacillus subtilis, a kinase cascade that activates master regulator Spo0A ~ P in response to starvation signals, is the core of a large network controlling the cell's decision to differentiate into sporulation and other phenotypes. This article reviews recent advances in understanding the origins and purposes of the complex dynamical behavior of the phosphorelay, which pulses with peaks of activity coordinated with the cell cycle. The transient imbalance in the expression of two critical genes caused by their strategic placement at opposing ends of the chromosome proved to be the key for this pulsed behavior. Feedback control loops in the phosphorelay use these pulses to implement a timer mechanism, which creates several windows of opportunity for phenotypic transitions over multiple generations. This strategy allows the cell to coordinate multiple differentiation programs in a decision process that fosters phenotypic diversity and adapts to current conditions.

Heterogeneity of genomic instabilities among individual patients is believed to be a major cause of drug response heterogeneity. Cancer patients who are sensitive to anti-cancer drugs are often re-examined to understand the unknown mechanism of action (MoA) of given drugs. For example, a non-small cell lung cancer (NSCLC) patient was reported to be responsive to Dasatinib treatment and remained cancer-free four years later. Though follow-up genomic analysis showed the patient bears an inactivating BRAF [1]mutation in the tumor, the MoA remains unclear. There are two challenges in uncovering the MoA. First, Dasatinib is a kinase inhibitor, which often has many protein targets. Second, the downstream MoA signaling pathways regulated by these targets are too complicated to delineate. Currently, there is no computational tool that can effectively address both challenges. To fill this gap, we developed a computational tool DrugMoaMiner (Drug MoA Miner) that can be used to identify the comprehensive set of kinase inhibitor targets; delineate the underlying drug MoA; and predict personalized sensitivity to a given drug based on an individual's gene expression profiles. We applied the DrugMoaMiner to lung cancer cell lines to uncover the potential MoA signaling network of Dasatinib sensitivity; our result is in agreement with previous protein data analysis. Moreover, we can predict Dasatinib response of an independent set of NSCLC cell lines using the MoA signaling network uncovered.

The Hippo pathway is an evolutionarily conserved signaling module that plays multiple roles in embryonic development. Components of the pathway, which includes a kinase cascade and a downstream complex composed of YAP and TEAD transcription factors, are dysregulated in a significant fraction of human cancers. In this issue of Genes & Development, Liu-Chittenden and colleagues (pp. 1300–1305) use genetic and pharmacological means to disrupt the active YAP–TEAD complex. As this intervention impedes tumorigenesis in the liver with no apparent effect on normal liver homeostasis, the work paves the way for the development of new strategies to target this pervasive oncogenic pathway.

Inhibition of rho kinase (ROCK) has been recognized as an important target for a number of diseases, including glaucoma. Herein we report SAR development around two hits from a kinase library that led to the discovery of the ROCK inhibitor compound 38. In vitro and in vivo analysis of this compound, including its effects in a monkey model of glaucoma will be discussed.

Scope Down syndrome (DS), caused by trisomy of human chromosome 21 (Hsa21), is characterized by a spectrum of phenotypes including skeletal abnormalities. The Ts65Dn DS mouse model exhibits similar skeletal phenotypes as humans with DS. DYRK1A, a kinase encoded on Hsa21, has been linked to deficiencies in bone homeostasis in DS mice and individuals with DS. Treatment with Epigallocatechin-3-gallate (EGCG), a known inhibitor of Dyrk1a, improves some skeletal abnormalities associated with DS in mice. EGCG supplements are widely available but the effectiveness of different EGCG-containing supplements has not been well studied. Methods and results Six commercially available supplements containing EGCG were analyzed, and two of these supplements were compared with pure EGCG for their impact on skeletal deficits in a DS mouse model. The results demonstrate differential effects of commercial supplements on correcting skeletal abnormalities in Ts65Dn mice. Different EGCG-containing supplements display differences in degradation, polyphenol content, and effects on trisomic bone. Conclusion This work suggests that the dose of EGCG and composition of EGCG-containing supplements may be important in correcting skeletal deficits associated with DS. Careful analyses of these parameters may lead to a better understanding of how to improve skeletal and other deficits that impair individuals with DS.

Distant metastases from thyroid cancer of follicular origin are uncommon. Treatment includes levothyroxine administration at suppressive doses, focal treatment modalities with surgery, external radiation therapy and thermal ablation, and radioiodine in patients with uptake of (131)I in their metastases. Two thirds of distant metastases will become refractory to radioiodine at some point, and when there is a significant tumor burden and documented progression on imaging, a treatment with a kinase inhibitor may provide benefits.

Imatinib, a kinase inhibitor, is currently approved for the treatment of chronic myeloid leukaemia, gastrointestinal stromal tumours (GIST), and other malignant conditions such as dermatofibrosarcoma protuberans. Treatment with imatinib is generally well tolerated, but some cutaneous adverse events (AEs), such as exanthematous papular eruptions and Stevens-Johnson syndrome have been reported. We report a case of a pityriasis rubra pilaris (PRP)-like eruption associated with this drug. Although cutaneous AEs associated with imatinib are relatively common (up to 69% of cases), no previous cases of PRP-like eruptions related to this drug have been described previously, to our knowledge.

The NLRP3 inflammasome has broad biomedical relevance, but its activation mechanisms are incompletely understood. NEK7, a kinase that regulates microtubules during mitosis, is identified as a critical and selective upstream regulator of NLRP3 inflammasome activation.

Chapter 9 illustrated the power of the wrapping concept as guidance to engineer specificity and enhance safety in a kinase inhibitor. Yet, only a universal selectivity filter, applicable to the entire human kinome—even to kinases with unreported structure——and to idiosyncratic variations of the kinome would be truly useful for the drug designer. This chapter thematically belongs to the bioinformatics realm and addresses this issue at the broadest possible level. The surveyed findings reveal that targeting the epistructural singularities defined by protein dehydrons ushers a new generation of drugs that enable a tighter control of specificity and a personalization of the treatment. The universality of this selectivity filter in the field of therapeutic interference with cell signaling is thus established. The concepts introduced in this chapter are further extended to the realm of personalized molecular therapy (“the right drug for the right person”), since this area is regarded as a major imperative of post-genomic medicine. This perception is reinforced almost daily as promising therapeutic agents are recalled because of idiosyncratic side effects detected in small subpopulations of patients. However pressing the need, rational approaches to personalized drug therapy will ultimately and pivotally depend on our ability to translate genomic individualities and variations into molecular biomarkers that can guide a patient-tailored design. This chapter addresses also this issue and describes how the wrapping design concept can be brought to fruition in the personalization of drug therapy. The chapter introduces plausible scenarios in which genomic idiosyncrasies and oncogenic variations may promote targetable differences in the wrapping patterns of the gene products. Ultimately, the chapter extends an invitation to adopt and exploit protein wrapping as a molecular biomarker for personalized medicine within an enabling platform to tailor drugs to patient idiosyncrasies.

2552 Background: Crizotinib is a kinase inhibitor approved for treating ALK+ and ROS1+ advanced non-small cell lung cancer. Since crizotinib undergoes hepatic metabolism, this phase 1 study evaluated the pharmacokinetics (PK) and safety of crizotinib in pts with liver dysfunction. Methods: Crizotinib-naïve pts with different types of advanced cancer (ALK and ROS1 status unknown), ≥ 18 yr old, and ECOG PS 0–2 were enrolled. Pts were assigned to groups A1 – D based on liver function: normal (A1/A2) = both AST and TB ≤ the upper limit of normal (ULN); mild impairment (B) = AST > ULN and TB ≤ ULN, or TB > 1.0 – 1.5 × ULN; moderate (C1/C2) = TB > 1.5 – 3 × ULN; severe (D) = TB > 3 × ULN. Starting dose was based on HI. Pts in A1 and A2 were matched for weight, age, gender, race and ECOG PS to pts in B and C2, respectively. Study objectives included PK, safety and antitumor activity. Results: 88 pts were enrolled in A1 (n=11), A2 (n=15), B (n=20), C1 (n=10), C2 (n=16) and D (n=16). The geometric means of PK parameters at steady-state (Cycle 2 Day 1) are shown below. 75% of pts experienced treatment-related AEs (TRAEs), 9 (81.8%), 14 (93.3%), 15 (75.0%), 6 (60.0%), 11 (68.8%) and 11 (68.8%) in groups A1, A2, B, C1, C2 and D, respectively. 25% of pts experienced Grade 3/4 TRAEs, 3 (27.3%), 3 (20.0%), 3 (15.0%), 1 (10%), 7 (43.8%), 5 (31.3%) in groups A1, A2, B, C1, C2 and D, respectively. Three (3.4%) pts, all in A2, experienced treatment-related SAEs. Two pts (10%) in B and 1 (6.3%) in C2 required dose reductions for TRAEs. TRAEs associated with permanent discontinuation of treatment occurred in 1 pt in A1, A2, C2 and D. Overall, 3 pts had partial responses with durations of 96, 17 and 17 wks; 25 pts had stable disease. Conclusions: Systemic exposures of crizotinib in pts with mild HI receiving 250 BID and in pts with moderate HI receiving 200 mg BID are comparable with that of pts with normal hepatic function at 250 mg BID. All TRAEs were manageable across the various levels of hepatic function. Clinical trial information: NCT01576406. [Table: see text]

San Francisco, San Francisco, CA. Glioblastoma (GBM), the most common primary brain tumor, numbers among the most aggressive of cancers. Although signaling from PI3K and AKT to mTOR is dysregulated prominently, we show here that blockade of these upstream targets affects mTOR activity minimally in glioma. Direct targeting using allosteric inhibitors (rapamycin) blocked mTORC1 incompletely, while we also show here that mTOR active site inhibitors (TORKi) have short residence times, limiting their efficacy preclinically. We therefore tested the third-generation mTOR inhbitior RapaLink-1 a TORKi to the mTORC1-specific binding domain of rapamycin, for activity in GBM. RapaLink-1 interacted with FKBP12, an abundant mTOR interacting protein, enabling accumulation of RapaLink-1 in tumor cells. RapaLink-1 showed better efficacy and durability than rapamycin or a TORKi, potently blocking cancer-derived, activating mutants of mTOR. RapaLink-1 drove regression of intracranial xenografts in-vivo, improving survival compared with earlier-generation inhibitors. Our studies re-establish mTOR as a central target in glioma, trace the failure of existing drugs to incomplete/nondurable inhibition of mTORC1, and offer a new class of mTORC1 inhibitors with improved potency and durability. Citation Format: QiWen Fan, Ozlem Aksoy, Robyn Wong, Shirin Ilkhanizadeh, Chris Novotny, William Gustafson, Albert Tuong, Geraldine Cayanan, Erin Simonds, Daphne Haas-Kogan, Joanna Phillips, Theo Nicolaides, Theo Nicolaides, Masanori Okaniwa, Kevan Shokat, William A. Weiss. A kinase inhibitor targeted to mTORC1 drives regression in glioblastoma. [abstract]. In: Proceedings of the AACR Special Conference on Translational Control of Cancer: A New Frontier in Cancer Biology and Therapy; 2016 Oct 27-30; San Francisco, CA. Philadelphia (PA): AACR; Cancer Res 2017;77(6 Suppl):Abstract nr IA27.

This Podcast features an interview with Alfred Singer, Gil Katz, and Leonid Pobezinsky, authors of a Research Article that appears in the 26 August 2014 issue of Science Signaling , about a microRNA that plays a role in the survival of T cells. During development in the thymus and after maturation and migration into the periphery, T cells require signaling through both the T cell receptor (TCR) and the interleukin-7 receptor (IL-7R) to survive. However, because sustained IL-7R signaling kills T cells, TCR signaling periodically inhibits IL-7R signaling to enable T cell survival. Katz et al . have identified a microRNA that is induced by T cell receptor activation and inhibits IL-7R signaling by reducing the abundance of Jak1, a kinase that transduces signaling downstream of IL-7R.

The RAS-RAF-MEK-ERK pathway is one of the best characterized kinase cascades. During the exploration of small molecules that inhibit RAF1 kinase, regorafenib (BAY 73-4506) was discovered as a multikinase inhibitor which demonstrated anti-cancer, anti-angiogenic, and apoptotic activities in metastatic colorectal cancer. This was not the first multikinase inhibitor discovered for the disease; indeed, before regorafenib was approved by FDA as a multikinase inhibitor for metastatic colorectal cancer in 2012, sorafenib (BAY 43-9006) had already been developed to be the first in the world as a multikinase inhibitor for malignancy. Indeed, the only difference between the two compounds is fluorine bound to its proximal phenyl ring although the end result is a considerably different profile, both as a kinase inhibitor as well as in its clinical application.In this drug discovery case history, the authors review the design, discovery, and development of both regorafenib and sorafenib from back in the 1990s. Furthermore, the authors highlight the drug's anti-cancer and anti-angiogenic properties as well as its efficacy, safety pharmacology and toxicology based on FDA documents.In order to better predict the efficacy of kinase inhibitors and to utilize them more efficiently, our understanding of drug discovery, the approaches for kinase profiling, and technologies needed for their development are paramount. Indeed, the authors believe that the field should better explore the use of predictive biomarkers that might be able to better assess these therapeutics. Pharmaceutical scientists must also consider the cost effectiveness of the targeted agents developed as a number of the drugs developed are very expensive.

The biosynthetic pathway allows the transport of newly synthesized proteins to the TGN via the reticulum endoplasmic and Golgi apparatus. However, many large particles reach the TGN by unconventional means. For instance, Herpes simplex virus type 1(HSV-1) capsids assemble within the nucleus, bud into the perinuclear space, fuse with the outer nuclear membrane and finally travel unenveloped towards the TGN. Given the central role of protein kinase D in the transport of small cargo from the TGN to the cell surface, we probed its potential contribution in HSV-1 egress, as a model for studying large cargo exiting from the TGN. Using a synchronized infection, we show that inactivation of protein kinase D with pharmacological inhibitors, a kinase dead mutant or siRNA all causes the retention of HSV-1 at the TGN. This highlights the role of PKD in viral exit and a dependence of the virus on the classical host cell machinery to leave the TGN, unlike its previous transport steps. Conceptually, this supports a model in which the TGN is a meeting point where conventional and unconventional routes encounter.

I like to make bread, and I even find the work of kneading it very satisfying. It is rhythmic work and rather strenuous exercise if I keep at it as long as I should. But in all my bread making, it never dawned on me that there was a similarity between the proteins in my muscles and in the bread I was wrestling with, yet it turns out to be the case. Along with the actin and myosin in muscle, there is another protein called titin; it is a kinase that forms long, elastic fibers to which myosin molecules bond in striated and cardiac muscle (Johnson & Quiocho 1996). Titin is a Titan of a molecule; it is the largest known protein, a single chain of almost 27,000 amino acids. It has a molecular weight of about 3 million, while few other proteins weigh more than 200,000 (Barinaga 1995). With its spring-like domains that unfold when a muscle is stretched, titin contributes elasticity to muscle (Erickson 1997). During normal contraction, the elasticity of titin balances the contractile forces produced by myosin, so the myosin filaments remain centered in the sarcomere (Keller 1997). Titin also helps muscle to resist overextension. But what has this to do with bread, except for the fact that the titin in arm muscles must get a workout during kneading? It turns out that kneading

A kinase inhibitor protected against synovial inflammation and joint destruction in a mouse model of rheumatoid arthritis.

The Doc toxin from bacteriophage P1 (of the phd-doc toxin-antitoxin system) has served as a model for the family of Doc toxins, many of which are harbored in the genomes of pathogens. We have shown previously that the mode of action of this toxin is distinct from the majority derived from toxin-antitoxin systems: it does not cleave RNA; in fact P1 Doc expression leads to mRNA stabilization. However, the molecular triggers that lead to translation arrest are not understood. The presence of a Fic domain, albeit slightly altered in length and at the catalytic site, provided a clue to the mechanism of P1 Doc action, as most proteins with this conserved domain inactivate GTPases through addition of an adenylyl group (also referred to as AMPylation). We demonstrated that P1 Doc added a single phosphate group to the essential translation elongation factor and GTPase, elongation factor (EF)-Tu. The phosphorylation site was at a highly conserved threonine, Thr-382, which was blocked when EF-Tu was treated with the antibiotic kirromycin. Therefore, we have established that Fic domain proteins can function as kinases. This distinct enzymatic activity exhibited by P1 Doc also solves the mystery of the degenerate Fic motif unique to the Doc family of toxins. Moreover, we have established that all characterized Fic domain proteins, even those that phosphorylate, target pivotal GTPases for inactivation through a post-translational modification at a single functionally critical acceptor site.