Brain Penetration of the ROS1/ALK Inhibitor Lorlatinib Confirmed by PET

Spotlight on the treatment of non-small cell lung cancer with rare genetic alterations and brain metastasis: Current status and future perspectives

In patients with non-small cell lung cancer (NSCLC), oncogenic variants present in <5% of cases are considered rare, the predominant of which include human epidermal growth factor receptor 2 (HER2) mutations, mesenchymal-epithelial transition (MET) alterations, c-ros oncogene 1 (ROS1) rearrangements, rearrangement during transfection (RET) fusions, v-raf mouse sarcoma virus oncogene homolog B1 (BRAF) mutations, and neurotrophic troponin receptor kinase (NTRK) fusions. Brain metastases (BMs) occur in approximately 10%-50% of patients with NSCLC harboring rare genetic variants. The recent advent of small-molecule tyrosine kinase inhibitors and macromolecular antibody-drug conjugates (ADCs) has conferred marked survival benefits to patients with NSCLC harboring rare driver alterations. Despite effective brain lesion control for most targeted agents and promising reports of intracranial remission associated with novel ADCs, BM continues to be a major therapeutic challenge. This review discusses the recent advances in the treatment of NSCLC with rare genetic variants and BM, with a particular focus on intracranial efficacy, and explores future perspectives on how best to treat these patients.

Tyrosine kinase inhibitors in cancers: Treatment optimization - Part I

A multitude of TKI has been developed and approved targeting various oncogenetic alterations. While these have provided improvements in efficacy compared with conventional chemotherapies, resistance to targeted therapies occurs. Mutations in the kinase domain result in the inability of TKI to inactivate the protein kinase. Also, gene amplification, increased protein expression and downstream activation or bypassing of signalling pathways are commonly reported mechanisms of resistance. Improved understanding of mechanisms involved in TKI resistance has resulted in the development of new generations of targeted agents. In a race against time, the search for new, more potent and efficient drugs, and/or combinations of drugs, remains necessary as new resistance mechanisms to the latest generation of TKI emerge. This review examines the various generations of TKI approved to date and their common mechanisms of resistance, focusing on TKI targeting BCR-ABL, epidermal growth factor receptor, anaplastic lymphoma kinase and BRAF/MEK tyrosine kinases.

Advances of clinically approved small-molecule drugs for the treatment of non-small cell lung cancer

Lung cancer continues to pose a significant challenge as a prominent contributor to global cancer-related mortality. Despite the considerable strides made in therapeutic interventions within the past decade, a substantial population of patients diagnosed with non-small cell lung cancer (NSCLC) still face the grim reality of an incurable condition. In the realm of optimal management strategies for individuals afflicted with locally advanced, yet amenable to surgical resection, NSCLC, a therapeutic approach encompassing chemoradiation stands as a fundamental component. Significant strides have been made in the therapeutic landscape of NSCLC during the preceding two decades, facilitating an enhanced comprehension of the underlying disease biology, and mechanisms governing tumor progression, as well as advancements in early detection modalities and multimodal therapeutic interventions. Nevertheless, the overall rates of curative interventions and survival outcomes for NSCLC continue to exhibit a discouragingly low trajectory, particularly in the context of metastatic disease. Hence, the imperative for sustained research endeavors in the realm of novel pharmaceutical agents and combinatorial therapeutic approaches remains paramount, with the overarching objective of broadening the scope of clinical advantages conferred upon a wider demographic of patients, thereby fostering tangible improvements in outcomes pertaining to NSCLC. The primary objective of this review is to provide an all-encompassing examination encompassing the clinical application and synthetic routes of specific drugs, with the explicit aim of disseminating invaluable knowledge that can inform future research and development endeavors focused on NSCLC.

Synthesis and clinical application of small-molecule inhibitors and PROTACs of anaplastic lymphoma kinase

Pharmacological interventions that specifically target protein products of oncogenes in tumors have surfaced as a propitious therapeutic approach. Among infrequent genetic alterations, rearrangements of the anaplastic lymphoma kinase (ALK) gene, typically involving a chromosome 2 inversion that culminates in a fusion with the echinoderm microtubule-associated protein like 4 (EML4), lead to anomalous expression and activation of ALK. The inhibition of autophosphorylation and subsequent blockade of signal transduction by ALK tyrosine kinase inhibitors (TKIs) has been observed to elicit anti-tumor effects. Currently, four generations of ALK-positive targeted drugs have been investigated, providing a promising outlook for patients. The aim of this review is to furnish a comprehensive survey of the synthesis and clinical application of prototypical small-molecule ALK inhibitors in both preclinical and clinical phases, offering guidance for further development of ALK inhibitors for cancer therapy.

The Riddle of the Sphinx: Progress in Leptomeningeal Metastasis of Non-Small Cell Lung Cancer

Leptomeningeal metastasis (LM) is a serious complication of advanced non-small cell lung cancer (NSCLC), and the incidence of LM has been increasing yearly in recent times. There is no consensus on the best treatment modality for LM, which underscores a difficult problem in the management of advanced NSCLC patients. The existing treatments include molecular targeted therapy, systemic chemotherapy, local radiotherapy, antivascular tumor therapy, intrathecal chemotherapy, and immunotherapy, but their efficacy is not satisfactory. In this article, we briefly describe the clinical manifestations, diagnosis, and treatment of NSCLC-LM and discuss progress regarding evaluation of the efficacy of LM treatment to better provide a necessary reference for clinical practice and clinical trial evaluation.

Spirocyclic Iodonium Ylides for Fluorine-18 Radiolabeling of Non-Activated Arenes: From Concept to Clinical Research

Positron emission tomography (PET) is a powerful imaging tool for drug discovery, clinical diagnosis, and monitoring of disease progression. Fluorine-18 is the most common radionuclide used for PET, but advances in radiotracer development have been limited by the historical lack of methodologies and precursors amenable to radiolabeling with fluorine-18. Radiolabeling of electron-rich (hetero)aromatic rings remains a long-standing challenge in the production of PET radiopharmaceuticals. In this personal account, we discuss the history of spirocyclic iodonium ylide precursors, from inception to applications in clinical research, for the incorporation of fluorine-18 into complex non-activated (hetero)aromatic rings.

Chemistry and Pharmacology of Fluorinated Drugs Approved by the FDA (2016-2022)

Fluorine is characterized by high electronegativity and small atomic size, which provide this molecule with the unique property of augmenting the potency, selectivity, metabolic stability, and pharmacokinetics of drugs. Fluorine (F) substitution has been extensively explored in drug research as a means of improving biological activity and enhancing chemical or metabolic stability. Selective F substitution onto a therapeutic or diagnostic drug candidate can enhance several pharmacokinetic and physicochemical properties such as metabolic stability and membrane permeation. The increased binding ability of fluorinated drug target proteins has also been reported in some cases. An emerging line of research on F substitution has been addressed by using 18F as a radiolabel tracer atom in the extremely sensitive methodology of positron emission tomography (PET) imaging. This review aims to report on the fluorinated drugs approved by the US Food and Drug Administration (FDA) from 2016 to 2022. It cites selected examples from a variety of therapeutic and diagnostic drugs. FDA-approved drugs in this period have a variety of heterocyclic cores, including pyrrole, pyrazole, imidazole, triazole, pyridine, pyridone, pyridazine, pyrazine, pyrimidine, triazine, purine, indole, benzimidazole, isoquinoline, and quinoline appended with either F-18 or F-19. Some fluorinated oligonucleotides were also authorized by the FDA between 2019 and 2022.

EML4-ALK biology and drug resistance in non-small cell lung cancer: a new phase of discoveries

Anaplastic lymphoma kinase (ALK) can be driven to oncogenic activity by different types of mutational events such as point-mutations, for example F1174L in neuroblastoma, and gene fusions, for example with echinoderm microtubule-associated protein-like 4 (EML4) in non-small cell lung cancer (NSCLC). EML4-ALK variants result from different breakpoints, generating fusions of different sizes and properties. The most common variants (Variant 1 and Variant 3) form cellular compartments with distinct physical properties. The presence of a partial, probably misfolded beta-propeller domain in variant 1 confers solid-like properties to the compartments it forms, greater dependence on Hsp90 for protein stability and higher cell sensitivity to ALK tyrosine kinase inhibitors (TKIs). These differences translate to the clinic because variant 3, on average, worsens patient prognosis and increases metastatic risk. Latest generation ALK-TKIs are beneficial for most patients with EML4-ALK fusions. However, resistance to ALK inhibitors can occur via point-mutations within the kinase domain of the EML4-ALK fusion, for example G1202R, reducing inhibitor effectiveness. Here, we discuss the biology of EML4-ALK variants, their impact on treatment response, ALK-TKI drug resistance mechanisms and potential combination therapies.

Drugging Hijacked Kinase Pathways in Pediatric Oncology: Opportunities and Current Scenario

Childhood cancer is considered rare, corresponding to ~3% of all malignant neoplasms in the human population. The World Health Organization (WHO) reports a universal occurrence of more than 15 cases per 100,000 inhabitants around the globe, and despite improvements in diagnosis, treatment and supportive care, one child dies of cancer every 3 min. Consequently, more efficient, selective and affordable therapeutics are still needed in order to improve outcomes and avoid long-term sequelae. Alterations in kinases' functionality is a trademark of cancer and the concept of exploiting them as drug targets has burgeoned in academia and in the pharmaceutical industry of the 21st century. Consequently, an increasing plethora of inhibitors has emerged. In the present study, the expression patterns of a selected group of kinases (including tyrosine receptors, members of the PI3K/AKT/mTOR and MAPK pathways, coordinators of cell cycle progression, and chromosome segregation) and their correlation with clinical outcomes in pediatric solid tumors were accessed through the R2: Genomics Analysis and Visualization Platform and by a thorough search of published literature. To further illustrate the importance of kinase dysregulation in the pathophysiology of pediatric cancer, we analyzed the vulnerability of different cancer cell lines against their inhibition through the Cancer Dependency Map portal, and performed a search for kinase-targeted compounds with approval and clinical applicability through the CanSAR knowledgebase. Finally, we provide a detailed literature review of a considerable set of small molecules that mitigate kinase activity under experimental testing and clinical trials for the treatment of pediatric tumors, while discuss critical challenges that must be overcome before translation into clinical options, including the absence of compounds designed specifically for childhood tumors which often show differential mutational burdens, intrinsic and acquired resistance, lack of selectivity and adverse effects on a growing organism.

Lorlatinib as a treatment for ALK-positive lung cancer

Lorlatinib, a third-generation ALK tyrosine kinase inhibitor, has been approved as a treatment for ALK-positive lung cancer. This review provides information regarding the pharmacology and clinical features of lorlatinib, including its efficacy and associated adverse events. Pivotal clinical trials are discussed along with the current status of lorlatinib as a treatment for ALK-positive lung cancer and future therapeutic challenges.

Evaluation of Lorlatinib Cerebrospinal Fluid Concentrations in Relation to Target Concentrations for ALK Inhibition

Lorlatinib is a third‐generation, brain‐penetrant anaplastic lymphoma kinase (ALK) and c‐ros oncogene 1 (ROS1) tyrosine kinase inhibitor (TKI) with robust intracranial activity in patients with ALK‐ or ROS1‐positive non‐small cell lung cancer (NSCLC). Data from the ongoing open‐label, single‐arm, multicenter, phase‐1/2 study of lorlatinib in patients with metastatic ALK‐ or ROS1‐positive NSCLC were used to further investigate the potential brain penetration of lorlatinib. Patients received escalating lorlatinib doses (10–200 mg once daily or 35–100 mg twice daily) or the approved dosing (100 mg daily). Plasma was collected from all patients, and cerebrospinal fluid (CSF) was collected at baseline and during the study from 5 patients with suspected or confirmed leptomeningeal carcinomatosis or carcinomatous meningitis. For those 5 patients, lorlatinib concentrations ranged from 2.64 to 125 ng/mL in the CSF and from 12.7 to 457 ng/mL in the plasma; free plasma concentrations ranged from 4.318 to 155.385 ng/mL. The CSF/free plasma ratio was 0.77 (R² = 0.96 and P < .001). Using a post‐hoc population pharmacokinetic model, the average steady‐state unbound plasma concentration of lorlatinib was derived and the CSF concentration was estimated for all patients. Known minimum efficacy concentrations (C_eff) for wild‐type and mutated (L1196M and G1202R) ALK were used to derive central nervous system (CNS) C_eff. Estimated CNS concentrations exceeded the derived CNS C_eff values in all patients for wild‐type ALK and the ALK L1196M mutation, and in 35.8% of patients for the ALK G1202R mutation. Projected lorlatinib CNS concentrations were consistent with the high intracranial response rates reported in clinical trials and provide further evidence of the potent CNS penetration of lorlatinib.

A Comprehensive Analysis of Metabolomics and Transcriptomics Reveals Novel Biomarkers and Mechanistic Insights on Lorlatinib Crosses the Blood-Brain Barrier

Of late, lorlatinib has played an increasingly pivotal role in the treatment of brain metastasis from non-small cell lung cancer. However, its pharmacokinetics in the brain and the mechanism of entry are still controversial. The purpose of this study was to explore the mechanisms of brain penetration by lorlatinib and identify potential biomarkers for the prediction of lorlatinib concentration in the brain. Detection of lorlatinib in lorlatinib-administered mice and control mice was performed using liquid chromatography and mass spectrometry. Metabolomics and transcriptomics were combined to investigate the pathway and relationships between metabolites and genes. Multilayer perceptron was applied to construct an artificial neural network model for prediction of the distribution of lorlatinib in the brain. Nine biomarkers related to lorlatinib concentration in the brain were identified. A metabolite-reaction-enzyme-gene interaction network was built to reveal the mechanism of lorlatinib. A multilayer perceptron model based on the identified biomarkers provides a prediction accuracy rate of greater than 85%. The identified biomarkers and the neural network constructed with these metabolites will be valuable for predicting the concentration of drugs in the brain. The model provides a lorlatinib to treat tumor brain metastases in the clinic.

Brain Penetration of Lorlatinib: Cumulative Incidences of CNS and Non-CNS Progression with Lorlatinib in Patients with Previously Treated ALK-Positive Non-Small-Cell Lung Cancer

Background

Lorlatinib is a potent, third-generation ALK/ROS1 tyrosine kinase inhibitor (TKI) designed to penetrate the blood–brain barrier.

Objective

We report the cumulative incidence of central nervous system (CNS) and non-CNS progression with lorlatinib in patients with ALK-positive non-small-cell lung cancer (NSCLC) previously treated with ALK TKIs.

Patients and methods

In an ongoing phase II study (NCT01970865), 198 patients with ALK-positive NSCLC with ≥ 1 prior ALK TKI were enrolled into expansion cohorts (EXP) based on treatment history. Patients received lorlatinib 100 mg once daily. Patients were analyzed for progressive disease, categorized as CNS or non-CNS progression, by independent central review. Cumulative incidence probabilities were calculated adopting a competing risks approach.

Results

Fifty-nine patients received crizotinib as their only prior ALK TKI (EXP2–3A); cumulative incidence rates (CIRs) of CNS and non-CNS progression were both 22% at 12 months in patients with baseline CNS metastases (n = 37), and CIR of non-CNS progression at 12 months was higher versus that for CNS progression in patients without baseline CNS metastases [43% vs. 9% (n = 22)]. In patients who received ≥ 1 prior second-generation ALK TKI [EXP3B–5 (n = 139)], CIR of non-CNS progression at 12 months was higher versus that for CNS progression in patients both with and without baseline CNS metastases (35% vs. 23% (n = 94) and 55% vs. 12% (n = 45), respectively).

Conclusions

Lorlatinib showed substantial intracranial activity in patients with pretreated ALK-positive NSCLC, with or without baseline CNS metastases, whose disease progressed on crizotinib or second-generation ALK TKIs.

ClinicalTrials.gov identifier

NCT01970865.

Electronic supplementary material

The online version of this article (10.1007/s11523-020-00702-4) contains supplementary material, which is available to authorized users.

Classification of Leptomeningeal Metastases from Solid Organ Malignancies and Clinical Outcomes: Series from a Cancer Research Centre

Leptomeningeal metastases (LMs) are a critical neurological manifestation of solid organ malignancies. Early diagnosis and prompt treatment is necessary to improve outcomes. We classified LM on the basis of cytological or histological and imaging studies. A total of 14 patients of LM from solid organ malignancies diagnosed between July 2016 and December 2018 were included in the series. LM was classified based on cerebrospinal fluid (CSF) cytology and magnetic resonance imaging (MRI) findings. Survival outcomes were noted. LM from carcinoma of breast and lung accounted for most of the cases. Type I LM was seen in 12 patients while 2 accounted for type II LM. Median overall survival (OS) was 40.5 days. Newer-generation tyrosine kinase inhibitor (TKI) therapy seems promising in the treatment of LM. Classification of LM based on cytology/histology and imaging findings allows early diagnosis and treatment. Newer-generation TKIs should be used for the treatment of LM if indicated.

Anaplastic lymphoma kinase inhibitors: an updated patent review (2014-2018)

Introduction: Anaplastic lymphoma kinase (ALK), a receptor tyrosine kinase, has been discovered in several cancers, including anaplastic large-cell lymphoma, non-small cell lung cancer, and inflammatory myofibroblastic tumors. The deregulation of ALK activities, such as translocation and point mutation, results in human carcinogenesis. The use of ALK inhibitors in clinical cancer treatment has been shown to be efficacious, and the issue of resistance to ALK inhibitors has been reported. Consequently, the development of a new generation of ALK inhibitors is necessary.Areas covered: This paper provides a comprehensive review of the patent literature from 2014 to 2018 including small molecule ALK inhibitors and their use as anticancer agents. The approved and developing ALK inhibitors are described.Expert commentary: The available three generations of ALK inhibitors have shown a good anticancer effect in ALK-positive non-small cell lung cancer. An urgent issue in this field is ALK resistance development. The development of new ALK inhibitors through structure modification of currently available ALK inhibitors is proceeding, such as the synthesis of macrocyclic compounds. This article arranges the ALK inhibitors that have published in the patent in recent years. It may help in the investigation of a new generation of ALK inhibitors, which can overcome the resistance issue and development of novel drug candidates in the future.

Interpretation of ceritinib clinical trial results and future combination therapy strategies for ALK-rearranged NSCLC

Introduction: Lung cancer is the leading cause of cancer-related deaths, with non-small cell lung cancer (NSCLC) accounting for approximately 85% of all lung cancer cases. The continued advancement of DNA sequencing technology and the discovery of multiple specific driver mutations underlying many cases of NSCLC are moving clinical intervention toward a more targeted approach. Here we focus on anaplastic lymphoma kinase (ALK), a member of the receptor tyrosine kinase family, as an oncogenic driver in NSCLC. The ALK gene is rearranged in 3-7% of NSCLCs, and targeted inhibition of ALK is a viable therapy option.Areas covered: We discuss the available treatment options for ALK-positive NSCLC with an emphasis on the second-generation ALK inhibitor ceritinib. We also discuss practical treatment strategies and possible strategies to overcome or delay resistance to ALK inhibitors.Expert opinion: With a robust treatment armamentarium for patients with ALK-positive NSCLC, emphasis has shifted to optimizing individualized treatment strategies to further enhance outcomes for these patients.

Novel derivatives of anaplastic lymphoma kinase inhibitors: Synthesis, radiolabeling, and preliminary biological studies of fluoroethyl analogues of crizotinib, alectinib, and ceritinib

Anaplastic lymphoma kinase (ALK), an oncogenic receptor tyrosine kinase, is a therapeutic target in various cancers, including non-small cell lung cancer. Although several ALK inhibitors, including crizotinib, ceritinib, and alectinib, are approved for cancer treatment, their long-term benefit is often limited by the cancer's acquisition of resistance owing to secondary point mutations in ALK. Importantly, some ALK inhibitors cannot cross the blood-brain barrier (BBB) and thus have little or no efficacy against brain metastases. The introduction of a lipophilic moiety, such as a fluoroethyl group may improve the drug's BBB penetration. Herein, we report the synthesis of fluoroethyl analogues of crizotinib 1, alectinib 4, and ceritinib 9, and their radiolabeling with ¹⁸F for pharmacokinetic studies. The fluoroethyl derivatives and their radioactive analogues were obtained in good yields with high purity and good molar activity. A cytotoxicity screen in ALK-expressing H2228 lung cancer cells showed that the analogues had up to nanomolar potency and the addition of the fluorinated moiety had minimal impact overall on the potency of the original drugs. Positron emission tomography in healthy mice showed that the analogues had enhanced BBB penetration, suggesting that they have therapeutic potential against central nervous system metastases.

Imaging techniques to study drug transporter function in vivo

Transporter systems involved in the permeation of drugs and solutes across biological membranes are recognized as key determinants of pharmacokinetics. Typically, the action of membrane transporters on drug exposure to tissues in living organisms is inferred from invasive procedures, which cannot be applied in humans. In recent years, imaging methods have greatly progressed in terms of instruments, synthesis of novel imaging probes as well as tools for data analysis. Imaging allows pharmacokinetic parameters in different tissues and organs to be obtained in a non-invasive or minimally invasive way. The aim of this overview is to summarize the current status in the field of molecular imaging of drug transporters. The overview is focused on human studies, both for the characterization of transport systems for imaging agents as well as for the determination of drug pharmacokinetics, and makes reference to animal studies where necessary. We conclude that despite certain methodological limitations, imaging has a great potential to study transporters at work in humans and that imaging will become an important tool, not only in drug development but also in medicine. Imaging allows the mechanistic aspects of transport proteins to be studied, as well as elucidating the influence of genetic background, pathophysiological states and drug-drug interactions on the function of transporters involved in the disposition of drugs.