Kinase Inhibitor Drugs Research Articles

Case report: Management of Progressive Lung Cancer Patients after First-Line EGFR Tyrosine Kinase Inhibitor Therapy

Various tyrosine kinase inhibitor (TKI) drugs have been widely used as therapy for cancer that has EGFR mutations, or abnormal EGFR activation. However, patients who have a mutation in the gene that activates EGFR only benefit from EGFR-TKI therapy for less than one year, because after that resistance occurs. In the management of patients according to NCCN 2017, patients who experience progress after receiving TKI as the first-line therapy must undergo an examination to identify the presence of T790M mutation. If the T790M mutation is positive, the choice of therapy that needs to be provided is the third generation (Osimertinib). Many recent studies have proved the significance of the effectiveness and response of Osimertinib therapy in lung cancer with EGFR T790M mutation. We reported the management of a pulmonary adenocarcinoma patient with positive EGFR mutation who had received first-line EGFR TKI who had progressive disease and T790M mutation in Dr. Seotomo Hospital. The patient finally received Osimertinib through an Early Access Program with a therapeutic response that improved significantly.

1549P - NTRK1-3 genomic fusions in non-small cell lung cancer (NSCLC) determined by comprehensive genomic profiling

BackgroundThe Neurotrophic Tyrosine Kinase genes, NTRK1-3 are extremely rare drivers of a wide variety of malignancies. The recent pan-cancer approval of kinase inhibitor drugs targeting NTRK has sparked interest in the frequency of NTRK rearrangements found in NSCLC. MethodsComprehensive genomic profiling (CGP) was performed on FFPE samples from 42,791 NSCLC cases. Tumor mutational burden (TMB) was determined on 0.8-1.1 Mbp of sequenced DNA and microsatellite instability (MSI) was determined on 95 loci. Results58 (0.1%) of the NSCLC featured genomic fusions or rearrangements in the NTRK1-3 genes (Table). The ages and genders of NTRK1-3 fusion+ cases were similar to NSCLC in general and did not enrich for younger patients. NTRK fusions were highest in adenocarcinomas (67%) and squamous cell carcinomas (SCC; 9%). The average genomic alterations (GA) per NTRK1-3 altered tumor ranged from 6.1 – 8.2 GA and was higher than that reported for EGFR, ALK and ROS1 driven NSCLC. The NTRK1-3 fusions involved a wide variety of fusion partners with NTRK1- IRF2BP2 (6) and NTRK1-TPM3 (9) most frequent. The levels of TMB and frequencies of PD-L1 expression were higher than EGFR, ALK and ROS1 altered cases. The STK11 GA frequencies were similar to NSCLC in general but lower than the frequency in lung adenocarcinoma only.Table1549PTableNTRK1NTRK2NTRK3Cases4756Median age/Range64 (22-88)68 (65-76)71 (63-74)Gender m/f23/243/25/1NSCLC Types Adenocarcinoma NSCLC NOS Large Cell Neuroendocrine SCC Sarcomatoid Large Cell31 10 2 2 1 14 14 2GA/tumor6.18.26.2TP5355%80%67%KRAS15%0%17%STK1111%20%0%MSI High0%0%0%Median TMB mut/Mb3.511.314.4TMB >10/20 mut/Mb22%/7%60%/20%67%/33%PD-L1 Expression low/high32%/16% (n=19)50%/50% (n=2)0%/33% (n=3) ConclusionsAlthough the addition of RNA sequencing may marginally increase their detection, based on this DNA-only CGP sequencing study, NTRK1-3 fusions are extremely rare in NSCLC. These NTRK1-3 fusion-driven NSCLC differ from other well-known driver associated NSCLC such as EGFR, ALK and ROS1 in their having higher GA/tumor, TMB and PD-L1 expression frequencies suggesting that immunotherapies may also be available for the care of these patients, possibly as a combination therapy. Legal entity responsible for the studyFoundation Medicine. FundingFoundation Medicine. DisclosureE.S. Sokol: Shareholder / Stockholder / Stock options, Full / Part-time employment: Foundation Medicine. S.E. Trabucco: Shareholder / Stockholder / Stock options, Full / Part-time employment: Foundation Medicine. D.X. Jin: Shareholder / Stockholder / Stock options, Full / Part-time employment: Foundation Medicine. G.M. Frampton: Shareholder / Stockholder / Stock options, Full / Part-time employment: Foundation Medicine. J.A. Elvin: Shareholder / Stockholder / Stock options, Full / Part-time employment: Foundation Medicine. J. Vergilio: Shareholder / Stockholder / Stock options, Full / Part-time employment: Foundation Medicine. J.K. Killian: Shareholder / Stockholder / Stock options, Full / Part-time employment: Foundation Medicine. N. Ngo: Shareholder / Stockholder / Stock options, Full / Part-time employment: Foundation Medicine. D. Lin: Shareholder / Stockholder / Stock options, Full / Part-time employment: Foundation Medicine. S. Ramkissoon: Shareholder / Stockholder / Stock options, Full / Part-time employment: Foundation Medicine. E. Severson: Shareholder / Stockholder / Stock options, Full / Part-time employment: Foundation Medicine. S.M. Ali: Shareholder / Stockholder / Stock options, Full / Part-time employment: Foundation Medicine. A.B. Schrock: Shareholder / Stockholder / Stock options, Full / Part-time employment: Foundation Medicine. J. Chung: Shareholder / Stockholder / Stock options, Full / Part-time employment: Foundation Medicine. P. Reddy: Shareholder / Stockholder / Stock options, Full / Part-time employment: Foundation Medicine. K. McGregor: Shareholder / Stockholder / Stock options, Full / Part-time employment: Foundation Medicine. B.M. Alexander: Leadership role, Shareholder / Stockholder / Stock options, Full / Part-time employment, Officer / Board of Directors: Foundation Medicine. J.S. Ross: Leadership role, Shareholder / Stockholder / Stock options, Full / Part-time employment: Foundation Medicine. All other authors have declared no conflicts of interest.

Activity-Based Kinome Profiling Using Chemical Proteomics and ATP Acyl Phosphates.

Human kinases are a large family of proteins (500+) that catalyze ATP-dependent phosphorylation of protein and metabolite substrates to regulate diverse facets of cell biology. Dysregulation and mutations of protein kinases are linked to human disease, providing opportunities for developing pharmacological agents as potential therapy. Assessing the selectivity of pharmacological compounds targeting this enzyme class is critical given that off-target activity of kinase inhibitor drugs may result in toxicity. This set of protocols outlines use of ATP acyl phosphate activity-based probes to evaluate the potency and selectivity of kinase inhibitors via fluorescent gel- and mass spectrometry-based detection methods. These competitive chemical proteomic assays can evaluate engagement of >200 native kinase targets directly in complex proteomes. © 2019 by John Wiley & Sons, Inc.

Targeted Therapy for Advanced Thyroid Cancer: Kinase Inhibitors and Beyond.

The treatment of advanced thyroid cancer has undergone rapid evolution in the last decade, with multiple kinase inhibitor drug approvals for each subtype of thyroid cancer and a number of other commercially available drugs that have been studied for this indication. Although most of the US Food and Drug Administration (FDA)-approved drugs are antiangiogenic multikinase inhibitors-vandetanib, cabozantinib, sorafenib, lenvatinib-there are two FDA indications that are mutation specific-dabrafenib/trametinib for BRAF-mutated anaplastic thyroid cancer and larotrectinib for NTRK-fusion thyroid cancer. Furthermore, other mutation-specific drugs, immunotherapies, and novel strategies for advanced thyroid cancer are under investigation. Understanding the molecular basis of thyroid cancer, the drugs of interest for treatment of advanced thyroid cancer, and how these drugs can be administered safely and in the appropriate clinical scenario are the topics of this review.

Abstract 4538: Global and phosphoproteomic analysis of AML cell line response to phosphatase inhibitor treatment

Abstract In the United States, approximately 21,000 people are diagnosed with AML each year and over 10,000 AML related deaths are reported. Genomic analysis has revealed at least 11 genetic classes of AML, and more than 20 subsets can be assigned when considering the differentiation states of Leukaemic blasts. This variability has generated significant interest in the development of targeted therapies for AML. However, complex mutational patterns and a lack of pharmacological agents for most mutational events have challenged the development of effective treatments. Recent results from the Beat AML clinical trial revealed that response to drugs is associated with mutational status, including instances where drug sensitivity is specific to combinatorial mutational events. To better understand the molecular mechanisms underpinning drug response, we performed global and phosphoproteomic analyses on 4 AML cell lines that carry mutations associated with AML: K562 with a BCR-ABL fusion, MOLM14 with a FLT3 mutation, HL60 with a RAS mutation, and CMK with a JAK3 mutation. These cell lines were each treated with a different kinase inhibitor drug for which they have a known sensitivity. Cell samples were collected prior to treatment and time points of 30 min, 3h, and 16 hrs. Frozen cell pellets were prepared for analysis using the workflow for multiplexed, deep-scale, proteome and phosphoproteome analysis developed by the NCI CPTAC program. The goal of our Proteogenomic Translational Research Center is to develop drug response signatures allowing the use of baseline proteome and phosphoproteome measurements to predict patient drug response, providing a foundation for rational selection of combination therapies. Preliminary analysis of the data show a dynamic temporal response to drug treatment in both the global and phosphoproteome, Figure 1. Current efforts are focused on combining knowledge-driven and data-driven analysis approaches to identify the pathways associated with drug response. Citation Format: Paul D. Piehowski, Jason E. McDermott, Joshua R. Hansen, Samantha L. Savage, Cristina E. Tognon, Anupriya Agarwal, Jeffrey W. Tyner, Brian J. Druker, Karin D. Rodland. Global and phosphoproteomic analysis of AML cell line response to phosphatase inhibitor treatment [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 4538.

Abstract 3589: Targeting metabolic reprogramming and OXPHOS as a viable anti-melanoma strategy

Abstract Invasive melanoma is an aggressive form of skin cancer with poor clinical outcomes. Nearly 50% of melanoma patients exhibit oncogenic BRAFV600E mutations. Existing BRAF kinase inhibitor drugs provide a short-term benefit prior to the rapid onset of drug resistance. Emerging results suggest that BRAF and other kinase inhibitors induce metabolic reprogramming from glycolytic energy production to oxidative phosphorylation (OXPHOS) in a subset of malignant melanomas. Metabolic reprogramming to OXPHOS is emerging as an important mechanism of resistance to BRAF kinase inhibitors and is associated with worse prognosis. Consequently, there is a significant opportunity for multimodal therapeutic approaches that selectively target the metabolic reprogramming associated with resistance to BRAF kinase inhibitors and promote immune-targeted therapy. We have previously developed mitochondria-targeted drugs by exploiting the enhanced negative mitochondrial membrane potential of cancer cells to selectively target and disrupt tumor growth. We hypothesized that metabolic reprogramming from glycolysis to OXPHOS in BRAF inhibitor-resistant melanoma cells would make them susceptible to OXPHOS inhibitors. In this study, we have modified the structure of a naturally occurring polyphenol, magnolol into a mitochondria-targeted-magnolol (Mito-MGN). We tested the effects of Mito-MGN on mitochondrial respiration and bioenergetic function, cellular redox status, and mitophagy in wild type (WT) and BRAF-resistant (metabolically reprogrammed) melanoma cells. Our data show that Mito-MGN inhibits mitochondrial respiration, melanoma cell proliferation and invasion at concentrations more than 200-fold lower than that of magnolol. Furthermore, Mito-MGN increases ROS formation and oxidation of mitochondrial peroxiredoxin. Preliminary results also indicate that BRAF inhibitor resistant melanoma cells exhibit enhanced OXPHOS as a consequence of metabolic reprogramming and that Mito-MGN effectively inhibits proliferation and mitochondrial respiration in the resistant cells. Mito-MGN inhibited mitochondrial complex I activity in both WT and resistant cells. The IC50 values to inhibit complex I-mediated respiration was consistent with the values calculated for inhibition of cell respiration. We conclude that inhibition of complex I is a key initial event that is responsible for the anti-proliferative effects observed in the presence of Mito-MGN against wild-type as well as drug-resistant melanoma cells. Citation Format: Gang Cheng, Jacek Zielonka, Micael Hardy, Michael B. Dwinell, Balaraman Kalyanaraman. Targeting metabolic reprogramming and OXPHOS as a viable anti-melanoma strategy [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 3589.

Abstract 3589: Targeting metabolic reprogramming and OXPHOS as a viable anti-melanoma strategy

Invasive melanoma is an aggressive form of skin cancer with poor clinical outcomes. Nearly 50% of melanoma patients exhibit oncogenic BRAFV600E mutations. Existing BRAF kinase inhibitor drugs provide a short-term benefit prior to the rapid onset of drug resistance. Emerging results suggest that BRAF and other kinase inhibitors induce metabolic reprogramming from glycolytic energy production to oxidative phosphorylation (OXPHOS) in a subset of malignant melanomas. Metabolic reprogramming to OXPHOS is emerging as an important mechanism of resistance to BRAF kinase inhibitors and is associated with worse prognosis. Consequently, there is a significant opportunity for multimodal therapeutic approaches that selectively target the metabolic reprogramming associated with resistance to BRAF kinase inhibitors and promote immune-targeted therapy. We have previously developed mitochondria-targeted drugs by exploiting the enhanced negative mitochondrial membrane potential of cancer cells to selectively target and disrupt tumor growth. We hypothesized that metabolic reprogramming from glycolysis to OXPHOS in BRAF inhibitor-resistant melanoma cells would make them susceptible to OXPHOS inhibitors. In this study, we have modified the structure of a naturally occurring polyphenol, magnolol into a mitochondria-targeted-magnolol (Mito-MGN). We tested the effects of Mito-MGN on mitochondrial respiration and bioenergetic function, cellular redox status, and mitophagy in wild type (WT) and BRAF-resistant (metabolically reprogrammed) melanoma cells. Our data show that Mito-MGN inhibits mitochondrial respiration, melanoma cell proliferation and invasion at concentrations more than 200-fold lower than that of magnolol. Furthermore, Mito-MGN increases ROS formation and oxidation of mitochondrial peroxiredoxin. Preliminary results also indicate that BRAF inhibitor resistant melanoma cells exhibit enhanced OXPHOS as a consequence of metabolic reprogramming and that Mito-MGN effectively inhibits proliferation and mitochondrial respiration in the resistant cells. Mito-MGN inhibited mitochondrial complex I activity in both WT and resistant cells. The IC 50 values to inhibit complex I-mediated respiration was consistent with the values calculated for inhibition of cell respiration. We conclude that inhibition of complex I is a key initial event that is responsible for the anti-proliferative effects observed in the presence of Mito-MGN against wild-type as well as drug-resistant melanoma cells. Citation Format: Gang Cheng, Jacek Zielonka, Micael Hardy, Michael B. Dwinell, Balaraman Kalyanaraman. Targeting metabolic reprogramming and OXPHOS as a viable anti-melanoma strategy [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 3589.

ZBTB46, SPDEF, and ETV6: Novel Potential Biomarkers and Therapeutic Targets in Castration-Resistant Prostate Cancer.

Prostate cancer (PCa) is the second most common killer among men in Western countries. Targeting androgen receptor (AR) signaling by androgen deprivation therapy (ADT) is the current therapeutic regime for patients newly diagnosed with metastatic PCa. However, most patients relapse and become resistant to ADT, leading to metastatic castration-resistant PCa (CRPC) and eventually death. Several proposed mechanisms have been proposed for CRPC; however, the exact mechanism through which CRPC develops is still unclear. One possible pathway is that the AR remains active in CRPC cases. Therefore, understanding AR signaling networks as primary PCa changes into metastatic CRPC is key to developing future biomarkers and therapeutic strategies for PCa and CRPC. In the current review, we focused on three novel biomarkers (ZBTB46, SPDEF, and ETV6) that were demonstrated to play critical roles in CRPC progression, epidermal growth factor receptor tyrosine kinase inhibitor (EGFR TKI) drug resistance, and the epithelial-to-mesenchymal transition (EMT) for patients treated with ADT or AR inhibition. In addition, we summarize how these potential biomarkers can be used in the clinic for diagnosis and as therapeutic targets of PCa.

Clinical efficacy analysis of pemetrexed combined with gefitinib in treatment of advanced non-small cell lung cancer after epidermal growth factor receptor-tyrosine kinase inhibitor drug resistance

Objective To investigate the clinical efficacy of pemetrexed alone or combined with gefitinib in treatment of advanced non-small cell lung cancer (NSCLC) after epidermal growth factor receptor-tyrosine kinase inhibitor (EGFR-TKI) drug resistance. Methods The clinical data of 80 patients with advanced NSCLC after EGFR-TKI drug resistance from August 2014 to April 2018 were retrospectively analyzed. They were divided into two groups according to their treatment regimens: 40 patients received pemetrexed alone (the control group) and 40 patients received pemetrexed combined with gefitinib (the observation group). The recent clinical efficacy, adverse reactions and the survival time of both groups were compared. The count data was compared by using χ 2 test or Fisher exact test. Kaplan-Meier method was used to make survival analysis and log-rank method was used to detect. Results The total effective rate of the observation group was higher than that of the control group [70.0% (28/40) vs. 32.5% (13/40), χ2 = 11.257, P = 0.001]. There was no statistical difference in the adverse reactions [17.5% (7/40) vs. 20.0% (8/40), χ2 = 0.082, P = 0.775]. The median progression-free survival time and median overall survival time of the observation group were longer than those of the control group (6.5 months vs. 3.5 months, 15.5 months vs. 8.5 months, all P < 0.01). Conclusion Pemetrexed combined with gefitinib has a recent favorable effect in advanced NSCLC after EGFR-TKI drug resistance, including low incidence of adverse reactions and prolonged survival time, which is worthy of further application. Key words: Carcinoma, non-small-cell lung; Drug resistance, neoplasm; Receptor, epidermal growth factor; Protein-tyrosine kinases; Enzyme inhibitors; Gefitinib; Pemetrexed

Inflammation Resolution and the Induction of Granulocyte Apoptosis by Cyclin-Dependent Kinase Inhibitor Drugs.

Inflammation is a necessary dynamic tissue response to injury or infection and it's resolution is essential to return tissue homeostasis and function. Defective or dysregulated inflammation resolution contributes significantly to the pathogenesis of many, often common and challenging to treat human conditions. The transition of inflammation to resolution is an active process, involving the clearance of inflammatory cells (granulocytes), a change of mediators and their receptors, and prevention of further inflammatory cell infiltration. This review focuses on the use of cyclin dependent kinase inhibitor drugs to pharmacologically target this inflammatory resolution switch, specifically through inducing granulocyte apoptosis and phagocytic clearance of apoptotic cells (efferocytosis). The key processes and pathways required for granulocyte apoptosis, recruitment of phagocytes and mechanisms of engulfment are discussed along with the cumulating evidence for cyclin dependent kinase inhibitor drugs as pro-resolution therapeutics.

Combined Cellular and Biochemical Profiling to Identify Predictive Drug Response Biomarkers for Kinase Inhibitors Approved for Clinical Use between 2013 and 2017

Kinase inhibitors form the largest class of precision medicine. From 2013 to 2017, 17 have been approved, with 8 different mechanisms. We present a comprehensive profiling study of all 17 inhibitors on a biochemical assay panel of 280 kinases and proliferation assays of 108 cancer cell lines. Drug responses of the cell lines were related to the presence of frequently recurring point mutations, insertions, deletions, and amplifications in 15 well-known oncogenes and tumor-suppressor genes. In addition, drug responses were correlated with basal gene expression levels with a focus on 383 clinically actionable genes. Cell lines harboring actionable mutations defined in the FDA labels, such as mutant BRAF(V600E) for cobimetinib, or ALK gene translocation for ALK inhibitors, are generally 10 times more sensitive compared with wild-type cell lines. This sensitivity window is more narrow for markers that failed to meet endpoints in clinical trials, for instance CDKN2A loss for CDK4/6 inhibitors (2.7-fold) and KRAS mutation for cobimetinib (2.3-fold). Our data underscore the rationale of a number of recently opened clinical trials, such as ibrutinib in ERBB2- or ERBB4-expressing cancers. We propose and validate new response biomarkers, such as mutation in FBXW7 or SMAD4 for EGFR and HER2 inhibitors, ETV4 and ETV5 expression for MEK inhibitors, and JAK3 expression for ALK inhibitors. Potentially, these new markers could be combined to improve response rates. This comprehensive overview of biochemical and cellular selectivities of approved kinase inhibitor drugs provides a rich resource for drug repurposing, basket trial design, and basic cancer research.

Predicting Blood⁻Brain Barrier Permeability of Marine-Derived Kinase Inhibitors Using Ensemble Classifiers Reveals Potential Hits for Neurodegenerative Disorders.

The recent success of small-molecule kinase inhibitors as anticancer drugs has generated significant interest in their application to other clinical areas, such as disorders of the central nervous system (CNS). However, most kinase inhibitor drug candidates investigated to date have been ineffective at treating CNS disorders, mainly due to poor blood–brain barrier (BBB) permeability. It is, therefore, imperative to evaluate new chemical entities for both kinase inhibition and BBB permeability. Over the last 35 years, marine biodiscovery has yielded 471 natural products reported as kinase inhibitors, yet very few have been evaluated for BBB permeability. In this study, we revisited these marine natural products and predicted their ability to cross the BBB by applying freely available open-source chemoinformatics and machine learning algorithms to a training set of 332 previously reported CNS-penetrant small molecules. We evaluated several regression and classification models, and found that our optimised classifiers (random forest, gradient boosting, and logistic regression) outperformed other models, with overall cross-validated model accuracies of 80%–82% and 78%–80% on external testing. All 3 binary classifiers predicted 13 marine-derived kinase inhibitors with appropriate physicochemical characteristics for BBB permeability.

Mast cells and neutrophils mediate peripheral motor pathway degeneration in ALS.

Neuroinflammation is a recognized pathogenic mechanism underlying motor neuron degeneration in amyotrophic lateral sclerosis (ALS), but the inflammatory mechanisms influencing peripheral motor axon degeneration remain largely unknown. A recent report showed a pathogenic role for c-Kit-expressing mast cells mediating inflammation and neuromuscular junction denervation in muscles from SOD1G93A rats. Here, we have explored whether mast cells infiltrate skeletal muscles in autopsied muscles from ALS patients. We report that degranulating mast cells were abundant in the quadriceps muscles from ALS subjects but not in controls. Mast cells were associated with myofibers and motor endplates and, remarkably, interacted with neutrophils forming large extracellular traps. Mast cells and neutrophils were also abundant around motor axons in the extensor digitorum longus muscle, sciatic nerve, and ventral roots of symptomatic SOD1G93A rats, indicating that immune cell infiltration extends along the entire peripheral motor pathway. Postparalysis treatment of SOD1G93A rats with the tyrosine kinase inhibitor drug masitinib prevented mast cell and neutrophil infiltration, axonal pathology, secondary demyelination, and the loss of type 2B myofibers, compared with vehicle-treated rats. These findings provide further evidence for a yet unrecognized contribution of immune cells in peripheral motor pathway degeneration that can be therapeutically targeted by tyrosine kinase inhibitors.

Mechanisms, monitoring, and management of tyrosine kinase inhibitors-associated cardiovascular toxicities.

The tyrosine kinase inhibitor (TKI) drug class is a prominently used option in the treatment of various cancers. Safety evaluation of these drugs has shown evidence of cardiotoxicity of varying frequency and severity between agents; concern has led to updated labeling, warning prescribers of such. This review seeks to clarify the present dangers and investigate cardiotoxic mechanisms of action for each discussed TKI. Dasatinib was connected primarily with an incidence of fluid retention, edema, QT prolongation, and pulmonary hypertension in clinical studies. It is theorized that this is due to a combination of off-target kinase binding and on-target binding of Bcr-Abl, and less likely, mitochondrial induced apoptosis. Studies showed sorafenib to carry the risk of hypertension, QT prolongation, and myocardial infarction. Proposed mechanisms for these side effects include inhibition of proteins, vascular endothelium growth factor receptor, hERG potassium channels, and the RAF/MERK/ERK pro-survival pathway. Finally, lapatinib showed evidence of decreased left ventricular ejection fraction (LVEF) and QT prolongation in clinical studies. The literature attributes these as side effects of on-target ErbB2 binding leading to mitochondrial induced apoptosis. The concern warranted by these findings is in question. Pooled safety data suggest that the overall risk for cardiotoxicity is minimal in dasatinib and lapatinib. Sorafenib seems to carry a moderate concern. For the discussed agents, recommendations agree that routine monitoring via methods such as electroencephalogram, cardiac biomarkers, and blood pressure is warranted during the course of treatment, in addition to a comprehensive collection of past medical history and risk factors to identify those at heightened risk for cardiovascular events.

In vitro UGT1A1 inhibition by tyrosine kinase inhibitors and association with drug-induced hyperbilirubinemia.

Hyperbilirubinemia has been observed in patients treated with tyrosine kinase inhibitor (TKI) drugs. Therefore, it would be beneficial to understand whether there is a relationship between inhibition of uridine-5'-diphosphate glucuronosyltransferase (UGT) 1A1 activity and observed bilirubin elevations in TKI drug-treated patients. UGT1A1 is responsible for the glucuronidation of bilirubin which leads to its elimination in the bile. To examine this question, an in vitro glucuronidation assay was developed to determine the inhibitory effect of TKI drugs employing human liver microsomes (HLM) with varying UGT1A1 activity. Utilizing β-estradiol as the UGT1A1 probe substrate, 20 TKI drugs were evaluated at concentrations that represent clinical plasma levels. Adverse event reports were searched to generate an empirical Bayes geometric mean (EGBM) score for clinical hyperbilirubinemia with the TKI drugs. Erlotinib, nilotinib, regorafenib, pazopanib, sorafenib and vemurafenib had IC50 values that were lower than their clinical steady-state Cmax concentrations. These TKI drugs had high incidences of hyperbilirubinemia and higher EBGM scores. The IC50 values and Cmax/IC50 ratios correlated well with EBGM scores for hyperbilirubinemia (P < 0.005). For the TKI drugs with higher incidence of hyperbilirubinemia in Gilbert syndrome patients, who have reduced UGT1A1 activity, six of eight had smaller ratios in the low UGT1A1 activity microsomes than the wild-type microsomes for drugs, indicating greater sensitivity to the drugs in this phenotype. These results suggest that in vitro UGT1A1 inhibition assays have the potential to predict clinical hyperbilirubinemia.

Clinical value of droplet digital polymerase chain reaction method in detecting plasma circulating tumor deoxyribonucleic acid epidermal growth factor receptor mutations in advanced pulmonary adenocarcinoma patients

Objective: To determine the clinical value of droplet digital polymerase chain reaction (ddPCR) method to detect plasma circulating tumor DNA (ctDNA) epidermal growth factor receptor (EGFR) mutations in advanced pulmonary adenocarcinoma. Methods: One hundred and thirty six patients with advanced pulmonary adenocarcinoma diagnosed in the Beijing Chest Hospital were collected from May 2015 to April 2017 for initial treatment. EGFR gene mutation in the plasma ctDNA was detected by both ddPCR and amplification refractory mutation system (ARMS) assays. EGFR gene mutation in the tumor tissue was detected by ARMS assay. Patients with EGFR sensitive mutations received first-line oral treatment with EGFR tyrosine kinase inhibitor (EGFR-TKI) drugs. The Kaplan-Meier survival analysis was used to compared the progression-free survival (PFS) in EGFR gene mutated patients detected with different methods. Results: Total of 111 samples (81.6%) were detected with EGFR gene mutations in 136 tumor tissue samples. In the 111 samples, 48 samples were found with exon21 L858R mutation (48/111, 43.2%), 59 samples were found with exon19 deletion mutations (59/111, 53.2%), and 4 cases were found with other mutations (4/111, 3.6%). Using tumor specimens as the gold standard, the sensitivity, specificity, and concordance rate of ARMS assay were 58.6%, 96.0%, and 65.4%, respectively; and those in ddPCR assay were 79.3%, 100%, and 83.1%, respectively; the coincidence rate was 83.1% (Kappa=0.685, P<0.001). Kaplan-Meier survival analysis showed that patients with EGFR gene mutation detected by both ddPCR and ARMS methods had shortest PFS when compared with those in patients detected positive with a single method of ddPCR or ARMS assay (11.6 moths vs 14.8 months, χ(2)=2.517, P=0.026). Conclusions: ddPCR is a reliable technology with high sensitivity and high specificity to detect EGFR gene mutations in plasma ctDNA in patients with advanced pulmonary adenocarcinoma. Plasma EGFR gene mutation may predict the efficacy of EGFR-TKI drugs.

Aberrant DNA methylation at HOXA4 and HOXA5 genes are associated with resistance to imatinib mesylate among chronic myeloid leukemia patients.

Imatinib mesylate is a molecularly targeted tyrosine kinase inhibitor drug. It is effectively used in the treatment of chronic myeloid leukemia (CML) patients. However, development of resistance to imatinib mesylate as a result of BCR-ABL dependent and BCR-ABL independent mechanisms has emerged as a daunting problem in the management of CML patients. Between these mechanisms, BCR-ABL independent mechanisms are still not robustly understood. To investigate the correlation of HOXA4 and HOXA5 promoter DNA hypermethylation with imatinib resistance among CML patients. Samples from 175 Philadelphia positive CML patients (83 good response and 92 BCR-ABL non-mutated imatinib resistant patients) were subjected to Methylation Specific High Resolution Melt Analysis for methylation levels quantification of the HOXA4 and HOXA5 promoter regions. Receiver operating characteristic curve analysis was done to elucidate the optimal methylation cut-off point followed by multiple logistic regression analysis. Log-Rank analysis was done to measure the overall survival difference between CML groups. The optimal methylation cut-off point was found to be at 62.5% for both HOXA4 and HOXA5. Chronic myeloid leukemia patients with ≥63% HOXA4 and HOXA5 methylation level were shown to have 3.78 and 3.95 times the odds, respectively, to acquire resistance to imatinib. However, overall survival of CML patients that have ≤62% and≥63% methylation levels of HOXA4 and HOXA5 genes were found to be not significant (P-value=0.126 for HOXA4; P-value=0.217 for HOXA5). Hypermethylation of the HOXA4 and HOXA5 promoter is correlated with imatinib resistance and with further investigation, it could be a potential epigenetic biomarker in supplement to the BCR-ABL gene mutation in predicting imatinib treatment response among CML patients but could not be considered as a prognostic marker.

Characteristics of Trials and Regulatory Pathways Leading to US Approval of Innovative vs. Non-Innovative Oncology Drugs

Background: Successful first-generation drugs can be updated or copied with small alterations to make drugs, which are less expensive to develop and carry less financial risk for manufacturers, since the mechanism of action has been validated and a well-defined consumer market exists. We compared the pivotal clinical trials and FDA approval pathways for first- and second-generation cancer drugs. Methods: Among cancer drugs approved in the US from 1994-2014, we found four classes of oncology drugs in which second-generation products followed many years after the first-generation agents: BCR-ABL tyrosine kinase inhibitors for treatment of chronic myelogenous leukemia, ALK tyrosine kinase inhibitors for non-small cell lung cancer, CD20 monoclonal antibodies for chronic lymphocytic leukemia and HER2 monoclonal antibodies for breast cancer. From information on these 13 drugs available in documents published by FDA at the time of approval, we extracted the following characteristics: approval pathway, pivotal trial design, number of participants, efficacy endpoints, and outcomes. Findings: The first-generation and 3 out of 4 second-generation BCR-ABL tyrosine kinase inhibitor drugs were granted expedited approval, while all 4 drugs were approved based on single-arm pivotal trials. Both ALK tyrosine kinase inhibitor drugs were based on single-arm trials and expedited regulatory review. The first-generation CD20 monoclonal antibody drug was approved based on single-arm trials, and 1 of the 2 second-generation drugs had pivotal trials that were randomized. All benefited from expedited approval. All 3 HER2 monoclonal antibodies in the sample were based on randomized trials and expedited pathways. Interpretation: Second-generation tyrosine kinase inhibitors and monoclonal antibodies used in cancer treatment were often approved through expedited approval pathways and studied in single-arm trials. Such pathways help facilitate the approval of these products for earlier use by patients, but are also associated with greater risk of post-approval safety-related labeling changes or unanticipated adverse events. Funding Statement: Dr. Kesselheim's work is funded by the Laura and John Arnold Foundation, with additional support from the Harvard Program in Therapeutic Science and the Engelberg Foundation. Dr. Vokinger's work is funded by the Swiss National Foundation. Declaration of Interest: The authors have declared no conflicts of interest.

Macrophilones from the Marine Hydroid Macrorhynchia philippina Can Inhibit ERK Cascade Signaling.

Six new macrophilone-type pyrroloiminoquines were isolated and identified from an extract of the marine hydroid Macrorhynchia philippina. The proton-deficient and heteroatom-rich structures of macrophilones B-G (2-7) were elucidated by spectroscopic analysis and comparison of their data with those of the previously reported metabolite macrophilone A (1). Compounds 1-7 are the first pyrroloiminoquines to be reported from a hydroid. The macrophilones were shown to inhibit the enzymatic conjugation of SUMO to peptide substrates, and macrophilones A (1) and C (3) exhibit potent and selective cytotoxic properties in the NCI-60 anticancer screen. Bioinformatic analysis revealed a close association of the cytotoxicity profiles of 1 and 3 with two known B-Raf kinase inhibitory drugs. While compounds 1 and 3 showed no kinase inhibitory activity, they resulted in a dramatic decrease in cellular protein levels of selected components of the ERK signal cascade. As such, the chemical scaffold of the macrophilones could provide small-molecule therapeutic leads that target the ERK signal transduction pathway.

ROCK inhibitors 2. Improving potency, selectivity and solubility through the application of rationally designed solubilizing groups

Solubilizing groups have been frequently appended to kinase inhibitor drug molecules when solubility is insufficient for pharmaceutical development. Such groups are usually located at substitution sites that have minimal impact on target activity. In this report we describe the incorporation of solubilizing groups in a class of Rho kinase (ROCK) inhibitors that not only confer improved solubility, but also enhance target potency and selectivity against a closely related kinase, PKA.