The burgeoning field of anaplastic lymphoma kinase (ALK) in cancer encompasses many cancer types, from very rare cancers to the more prevalent non-small-cell lung cancer (NSCLC). The common ...activation of ALK has led to the use of the ALK tyrosine kinase inhibitor (TKI) crizotinib in a range of patient populations and to the rapid development of second-generation drugs targeting ALK. In this Review, we discuss our current understanding of ALK function in human cancer and the implications for tumour treatment.
Infant gliomas have paradoxical clinical behavior compared to those in children and adults: low-grade tumors have a higher mortality rate, while high-grade tumors have a better outcome. However, we ...have little understanding of their biology and therefore cannot explain this behavior nor what constitutes optimal clinical management. Here we report a comprehensive genetic analysis of an international cohort of clinically annotated infant gliomas, revealing 3 clinical subgroups. Group 1 tumors arise in the cerebral hemispheres and harbor alterations in the receptor tyrosine kinases ALK, ROS1, NTRK and MET. These are typically single-events and confer an intermediate outcome. Groups 2 and 3 gliomas harbor RAS/MAPK pathway mutations and arise in the hemispheres and midline, respectively. Group 2 tumors have excellent long-term survival, while group 3 tumors progress rapidly and do not respond well to chemoradiation. We conclude that infant gliomas comprise 3 subgroups, justifying the need for specialized therapeutic strategies.
FDA-approved small-molecule kinase inhibitors Wu, Peng; Nielsen, Thomas E; Clausen, Mads H
Trends in pharmacological sciences (Regular ed.),
07/2015, Volume:
36, Issue:
7
Journal Article
Peer reviewed
Open access
Highlights • The classification of small-molecule kinase inhibitors is delineated. • All FDA-approved small-molecule kinase inhibitors (at April 2015) are presented according to binding mechanism and ...common structural features. • The current landscape and major challenges in kinase inhibition are discussed. • Possible future directions in developing novel kinase inhibitors are proposed.
Most patients with anaplastic lymphoma kinase (ALK)-rearranged or ROS proto-oncogene 1 (ROS1)-rearranged non-small-cell lung cancer (NSCLC) are sensitive to tyrosine kinase inhibitor (TKI) therapy, ...but resistance invariably develops, commonly within the CNS. This study aimed to analyse the safety, efficacy, and pharmacokinetic properties of lorlatinib, a novel, highly potent, selective, and brain-penetrant ALK and ROS1 TKI with preclinical activity against most known resistance mutations, in patients with advanced ALK-positive or ROS1-positive NSCLC.
In this international multicentre, open-label, single-arm, first-in-man phase 1 dose-escalation study, eligible patients had advanced ALK-positive or ROS1-positive NSCLC and were older than 18 years, with an Eastern Cooperative Oncology Group performance status of 0 or 1, and adequate end-organ function. Lorlatinib was administered orally to patients at doses ranging from 10 mg to 200 mg once daily or 35 mg to 100 mg twice daily, with a minimum of three patients receiving each dose. For some patients, tumour biopsy was done before lorlatinib treatment to identify ALK resistance mutations. Safety was assessed in patients who received at least one dose of lorlatinib; efficacy was assessed in the intention-to-treat population (patients who received at least one dose of study treatment and had either ALK or ROS1 rearrangement). The primary endpoint was dose-limiting toxicities during cycle 1 according to investigator assessment; secondary endpoints included safety, pharmacokinetics, and overall response. This study is ongoing and is registered with ClinicalTrials.gov, number NCT01970865.
Between Jan 22, 2014, and July 10, 2015, 54 patients received at least one dose of lorlatinib, including 41 (77%) with ALK-positive and 12 (23%) with ROS1-positive NSCLC; one patient had unconfirmed ALK and ROS1 status. 28 (52%) patients had received two or more TKIs, and 39 (72%) patients had CNS metastases. The most common treatment-related adverse events among the 54 patients were hypercholesterolaemia (39 72% of 54 patients), hypertriglyceridaemia (21 39% of 54 patients), peripheral neuropathy (21 39% of 54 patients), and peripheral oedema (21 39% of 54 patients). One dose-limiting toxicity occurred at 200 mg (the patient did not take at least 16 of 21 prescribed total daily doses in cycle 1 because of toxicities attributable to study drug, which were grade 2 neurocognitive adverse events comprising slowed speech and mentation and word-finding difficulty). No maximum tolerated dose was identified. The recommended phase 2 dose was selected as 100 mg once daily. For ALK-positive patients, the proportion of patients who achieved an objective response was 19 (46%) of 41 patients (95% CI 31–63); for those who had received two or more TKIs, the proportion of patients with an objective response was 11 (42%) of 26 patients (23–63). In ROS1-positive patients, including seven crizotinib-pretreated patients, an objective response was achieved by six (50%) of 12 patients (95% CI 21–79).
In this phase 1, dose-escalation study, lorlatinib showed both systemic and intracranial activity in patients with advanced ALK-positive or ROS1-positive NSCLC, most of whom had CNS metastases and had previously had two or more TKI treatments fail. Therefore, lorlatinib might be an effective therapeutic strategy for patients with ALK-positive NSCLC who have become resistant to currently available TKIs, including second-generation ALK TKIs, and is being investigated in a phase 3 randomised controlled trial comparing lorlatinib to crizotinib (ClinicalTrials.gov, NCT03052608).
Pfizer.
A vast array of oncogenic variants has been identified for anaplastic lymphoma kinase (ALK). Therefore, there is a need to better understand the role of ALK in cancer biology in order to optimise ...treatment strategies. This review summarises the latest research on the receptor tyrosine kinase ALK, and how this information can guide the management of patients with cancer that is ALK-positive. A variety of ALK gene alterations have been described across a range of tumour types, including point mutations, deletions and rearrangements. A wide variety of ALK fusions, in which the kinase domain of ALK and the amino-terminal portion of various protein partners are fused, occur in cancer, with echinoderm microtubule-associated protein-like 4 (EML4)-ALK being the most prevalent in non-small-cell lung cancer (NSCLC). Different ALK fusion proteins can mediate different signalling outputs, depending on properties such as subcellular localisation and protein stability. The ALK fusions found in tumours lack spatial and temporal regulation, which can also affect dimerisation and substrate specificity. Two ALK tyrosine kinase inhibitors (TKIs), crizotinib and ceritinib, are currently approved in Europe for use in ALK-positive NSCLC and several others are in development. These ALK TKIs bind slightly differently within the ATP-binding pocket of the ALK kinase domain and are associated with the emergence of different resistance mutation patterns during therapy. This emphasises the need to tailor the sequence of ALK TKIs according to the ALK signature of each patient. Research into the oncogenic functions of ALK, and fast paced development of ALK inhibitors, has substantially improved outcomes for patients with ALK-positive NSCLC. Limited data are available surrounding the physiological ligand-stimulated activation of ALK signalling and further research is needed. Understanding the role of ALK in tumour biology is key to further optimising therapeutic strategies for ALK-positive disease.
Clinical benefits of reperfusion after myocardial infarction are offset by maladaptive innate immune cell function, and therapeutic interventions are lacking.
We sought to test the significance of ...phagocytic clearance by resident and recruited phagocytes after myocardial ischemia reperfusion.
In humans, we discovered that clinical reperfusion after myocardial infarction led to significant elevation of the soluble form of MerTK (myeloid-epithelial-reproductive tyrosine kinase; ie, soluble MER), a critical biomarker of compromised phagocytosis by innate macrophages. In reperfused mice, macrophage
deficiency led to decreased cardiac wound debridement, increased infarct size, and depressed cardiac function, newly implicating MerTK in cardiac repair after myocardial ischemia reperfusion. More notably,
) mice, which are resistant to cleavage, showed significantly reduced infarct sizes and improved systolic function. In contrast to other cardiac phagocyte subsets, resident cardiac MHCII
CCR2
(major histocompatibility complex II/C-C motif chemokine receptor type 2) macrophages expressed higher levels of MerTK and, when exposed to apoptotic cells, secreted proreparative cytokines, including transforming growth factor-β.
deficiency compromised the accumulation of MHCII
phagocytes, and this was rescued in
) mice. Interestingly, blockade of CCR2-dependent monocyte infiltration into the heart reduced soluble MER levels post-ischemia reperfusion.
Our data implicate monocyte-induced MerTK cleavage on proreparative MHCII
cardiac macrophages as a novel contributor and therapeutic target of reperfusion injury.
A long-standing mystery shrouds the mechanism by which catalytically repressed receptor tyrosine kinase domains accomplish transphosphorylation of activation loop (A-loop) tyrosines. Here we show ...that this reaction proceeds via an asymmetric complex that is thermodynamically disadvantaged because of an electrostatic repulsion between enzyme and substrate kinases. Under physiological conditions, the energetic gain resulting from ligand-induced dimerization of extracellular domains overcomes this opposing clash, stabilizing the A-loop-transphosphorylating dimer. A unique pathogenic fibroblast growth factor receptor gain-of-function mutation promotes formation of the complex responsible for phosphorylation of A-loop tyrosines by eliminating this repulsive force. We show that asymmetric complex formation induces a more phosphorylatable A-loop conformation in the substrate kinase, which in turn promotes the active state of the enzyme kinase. This explains how quantitative differences in the stability of ligand-induced extracellular dimerization promotes formation of the intracellular A-loop-transphosphorylating asymmetric complex to varying extents, thereby modulating intracellular kinase activity and signaling intensity.
Anaplastic lymphoma kinase (ALK) is a receptor tyrosine kinase physiologically expressed by fetal neural cells. However, aberrantly expressed ALK is involved in the pathogenesis of diverse ...malignancies, including distinct types of lymphoma, lung carcinoma, and neuroblastoma. The aberrant ALK expression in nonneural cells results from chromosomal translocations that create novel fusion proteins. These protein hybrids compose the proximal part of a partner gene, including its promoter region, and the distal part of ALK, including the coding sequence for the entire kinase domain. ALK was first identified in a subset of T-cell lymphomas with anaplastic large cell lymphoma (ALCL) morphology (ALK+ ALCL), the vast majority of which harbor the well-characterized nucleophosmin (NPM)-ALK fusion protein. NPM-ALK co-opts several intracellular signal transduction pathways, foremost being the STAT3 pathway, normally activated by cytokines from the interleukin-2 (IL-2) family to promote cell proliferation and to inhibit apoptosis. Many genes and proteins modulated by NPM-ALK are also involved in evasion of antitumor immune response, protection from hypoxia, angiogenesis, DNA repair, cell migration and invasiveness, and cell metabolism. In addition, NPM-ALK uses epigenetic silencing mechanisms to downregulate tumor suppressor genes to maintain its own expression. Importantly, NPM-ALK is capable of transforming primary human CD4+ T cells into immortalized cell lines indistinguishable from patient-derived ALK+ ALCL. Preliminary clinical studies indicate that inhibition of NPM-ALK induces long-lasting complete remissions in a large subset of heavily pretreated adult patients and the vast majority of children with high-stage ALK+ ALCL. Combining ALK inhibition with other novel therapeutic modalities should prove even more effective.
Neuroblastoma, a tumour derived from the peripheral sympathetic nervous system, is one of the most frequent solid tumours in childhood. It usually occurs sporadically but familial cases are observed, ...with a subset of cases occurring in association with congenital malformations of the neural crest being linked to germline mutations of the PHOX2B gene. Here we conducted genome-wide comparative genomic hybridization analysis on a large series of neuroblastomas. Copy number increase at the locus encoding the anaplastic lymphoma kinase (ALK) tyrosine kinase receptor was observed recurrently. One particularly informative case presented a high-level gene amplification that was strictly limited to ALK, indicating that this gene may contribute on its own to neuroblastoma development. Through subsequent direct sequencing of cell lines and primary tumour DNAs we identified somatic mutations of the ALK kinase domain that mainly clustered in two hotspots. Germline mutations were observed in two neuroblastoma families, indicating that ALK is a neuroblastoma predisposition gene. Mutated ALK proteins were overexpressed, hyperphosphorylated and showed constitutive kinase activity. The knockdown of ALK expression in ALK-mutated cells, but also in cell lines overexpressing a wild-type ALK, led to a marked decrease of cell proliferation. Altogether, these data identify ALK as a critical player in neuroblastoma development that may hence represent a very attractive therapeutic target in this disease that is still frequently fatal with current treatments.
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