The ALK inhibitors, alectinib and ceritinib, induce ALK-independent and STAT3-dependent glioblastoma cell death

Small Molecule Tyrosine Kinase Inhibitors (TKIs) for Glioblastoma Treatment

In the last decade, many small molecules, usually characterized by heterocyclic scaffolds, have been designed and synthesized as tyrosine kinase inhibitors (TKIs). Among them, several compounds have been tested at preclinical and clinical levels to treat glioblastoma multiforme (GBM). GBM is the most common and aggressive type of cancer originating in the brain and has an unfavorable prognosis, with a median survival of 15-16 months and a 5-year survival rate of 5%. Despite recent advances in treating GBM, it represents an incurable disease associated with treatment resistance and high recurrence rates. For these reasons, there is an urgent need for the development of new pharmacological agents to fight this malignancy. In this review, we reported the compounds published in the last five years, which showed promising activity in GBM preclinical models acting as TKIs. We grouped the compounds based on the targeted kinase: first, we reported receptor TKIs and then, cytoplasmic and peculiar kinase inhibitors. For each small molecule, we included the chemical structure, and we schematized the interaction with the target for some representative compounds with the aim of elucidating the mechanism of action. Finally, we cited the most relevant clinical trials.

Molecular Targeted Therapies in Glioblastoma Multiforme: A Systematic Overview of Global Trends and Findings

This systematic review assesses current molecular targeted therapies for glioblastoma multiforme (GBM), a challenging condition with limited treatment options. Using PRISMA methodology, 166 eligible studies, involving 2526 patients (61.49% male, 38.51% female, with a male-to-female ratio of 1.59/1), were analyzed. In laboratory studies, 52.52% primarily used human glioblastoma cell cultures (HCC), and 43.17% employed animal samples (mainly mice). Clinical participants ranged from 18 to 100 years, with 60.2% using combined therapies and 39.8% monotherapies. Mechanistic categories included Protein Kinase Phosphorylation (41.6%), Cell Cycle-Related Mechanisms (18.1%), Microenvironmental Targets (19.9%), Immunological Targets (4.2%), and Other Mechanisms (16.3%). Key molecular targets included Epidermal Growth Factor Receptor (EGFR) (10.8%), Mammalian Target of Rapamycin (mTOR) (7.2%), Vascular Endothelial Growth Factor (VEGF) (6.6%), and Mitogen-Activated Protein Kinase (MEK) (5.4%). This review provides a comprehensive assessment of molecular therapies for GBM, highlighting their varied efficacy in clinical and laboratory settings, ultimately impacting overall and progression-free survival in GBM management.

ALK fusions in the pan-cancer setting: another tumor-agnostic target?

Anaplastic lymphoma kinase (ALK) alterations (activating mutations, amplifications, and fusions/rearrangements) occur in ~3.3% of cancers. ALK fusions/rearrangements are discerned in >50% of inflammatory myofibroblastic tumors (IMTs) and anaplastic large cell lymphomas (ALCLs), but only in ~0.2% of other cancers outside of non-small cell lung cancer (NSCLC), a rate that may be below the viability threshold of even large-scale treatment trials. Five ALK inhibitors -alectinib, brigatinib, ceritinb, crizotinib, and lorlatinib-are FDA approved for ALK-aberrant NSCLCs, and crizotinib is also approved for ALK-aberrant IMTs and ALCL, including in children. Herein, we review the pharmacologic tractability of ALK alterations, focusing beyond NSCLC. Importantly, the hallmark of approved indications is the presence of ALK fusions/rearrangements, and response rates of ~50-85%. Moreover, there are numerous reports of ALK inhibitor activity in multiple solid and hematologic tumors (e.g., histiocytosis, leiomyosarcoma, lymphoma, myeloma, and colorectal, neuroendocrine, ovarian, pancreatic, renal, and thyroid cancer) bearing ALK fusions/rearrangements. Many reports used crizotinib or alectinib, but each of the approved ALK inhibitors have shown activity. ALK inhibitor activity is also seen in neuroblastoma, which bear ALK mutations (rather than fusions/rearrangements), but response rates are lower (~10-20%). Current data suggests that ALK inhibitors have tissue-agnostic activity in neoplasms bearing ALK fusions/rearrangements.

Systematic Review of Molecular Targeted Therapies for Adult-Type Diffuse Glioma: An Analysis of Clinical and Laboratory Studies

Gliomas are the most common brain tumor in adults, and molecularly targeted therapies to treat gliomas are becoming a frequent topic of investigation. The current state of molecular targeted therapy research for adult-type diffuse gliomas has yet to be characterized, particularly following the 2021 WHO guideline changes for classifying gliomas using molecular subtypes. This systematic review sought to characterize the current state of molecular target therapy research for adult-type diffuse glioma to better inform scientific progress and guide next steps in this field of study. A systematic review was conducted in accordance with PRISMA guidelines. Studies meeting inclusion criteria were queried for study design, subject (patients, human cell lines, mice, etc.), type of tumor studied, molecular target, respective molecular pathway, and details pertaining to the molecular targeted therapy-namely the modality, dose, and duration of treatment. A total of 350 studies met the inclusion criteria. A total of 52 of these were clinical studies, 190 were laboratory studies investigating existing molecular therapies, and 108 were laboratory studies investigating new molecular targets. Further, a total of 119 ongoing clinical trials are also underway, per a detailed query on clinicaltrials.gov. GBM was the predominant tumor studied in both ongoing and published clinical studies as well as in laboratory analyses. A few studies mentioned IDH-mutant astrocytomas or oligodendrogliomas. The most common molecular targets in published clinical studies and clinical trials were protein kinase pathways, followed by microenvironmental targets, immunotherapy, and cell cycle/apoptosis pathways. The most common molecular targets in laboratory studies were also protein kinase pathways; however, cell cycle/apoptosis pathways were the next most frequent target, followed by microenvironmental targets, then immunotherapy pathways, with the wnt/β-catenin pathway arising in the cohort of novel targets. In this systematic review, we examined the current evidence on molecular targeted therapy for adult-type diffuse glioma and discussed its implications for clinical practice and future research. Ultimately, published research falls broadly into three categories-clinical studies, laboratory testing of existing therapies, and laboratory identification of novel targets-and heavily centers on GBM rather than IDH-mutant astrocytoma or oligodendroglioma. Ongoing clinical trials are numerous in this area of research as well and follow a similar pattern in tumor type and targeted pathways as published clinical studies. The most common molecular targets in all study types were protein kinase pathways. Microenvironmental targets were more numerous in clinical studies, whereas cell cycle/apoptosis were more numerous in laboratory studies. Immunotherapy pathways are on the rise in all study types, and the wnt/β-catenin pathway is increasingly identified as a novel target.

An update on Alectinib: a first line treatment for ALK-positive advanced lung cancer

INTRODUCTION

Alectinib is a second-generation, anaplastic lymphoma kinase (ALK) tyrosine kinase inhibitor (TKI) for the treatment of ALK+ non-small cell lung cancer (NSCLC) and is able to induce significant and durable CNS responses. However, long-term use of alectinib has been clinically reported to cause some serious and even life-threatening adverse events. There are currently no effective interventions for its adverse events, and this undoubtedly leads to delays in patient treatment and limits its long-term clinical use.

AREAS COVERED

Based on the clinical trials conducted so far, we summarize the efficacy and adverse events that occurred, especially those related to cardiovascular disorders, gastrointestinal disorders, hepatobiliary disorders, musculoskeletal and connective tissue disorders, skin and subcutaneous tissue disorders, and respiratory disorders. The factors that may influence alectinib selection are also described. Findings are based on a PubMed literature search of clinical and basic science research papers spanning 1998-2023.

EXPERT OPINION

The significant prolongation of patient survival compared with first-generation ALK inhibitor suggests its potential as a first-line treatment for the NSCLC, but the severe adverse events of alectinib limit its long-term clinical use. Future research should focus on the exact mechanisms of these toxicities, how to alleviate the adverse events caused by alectinib clinically, and the development of next-generation drugs with reduced toxicities.

Hit discovery of novel 2-phenyl-substituted 4-amino-6,7-dihydro-5H-cyclopenta[d]pyrimidines as potential anti-glioblastoma therapeutics: Design, synthesis, biological evaluation, and computational screening

Glioblastoma multiforme (GBM) is a highly-aggressive, dreadful disease with poor prognosis and disappointing clinical success. There is an unmet medical need of molecularly-targeted therapeutics for GBM treatment. In the present work, a series of novel 2-phenyl-substituted 4-amino-6,7-dihydro-5H-cyclopenta[d]pyrimidines was designed, synthesized, purified, characterized, and evaluated for cytotoxicity against glioblastoma cell line U87-MG. The design process (virtual library enumeration around the core, physicochemical and molecular property prediction/calculation of the designs, filtering the undesirable ones, and the diversity analyses of the lead-like designs), was carefully curated so as to obtain a set of structurally-diverse, novel molecules (total 20), with a particular focus on the relatively unexplored core structure, 6,7-dihydro-5H-cyclopenta[d]pyrimidine. The preliminary screening was done using MTT assay at 10 and 100 μM concentrations of the title compounds F₁ -F₂₀ and positive control cisplatin, which yielded six hits (% inhibition at 10 μM: ~50%)-F₂ , F₃ , F₅ , F₇ , F₁₅ , and F₂₀ , which were taken up for IC₅₀ determination. The top hits F₂ and F₇ (IC₅₀  < 10 μM) were further used for computational studies such as target prediction, followed by their molecular docking in the binding sites of the top-3 predicted targets (epidermal growth factor receptor kinase domain, cyclin-dependent kinase 2 [CDK2]) /cyclin E, and anaplastic lymphoma kinase [ALK]). The docking pose analyses revealed interesting trends. The relatively planar core structure, presence of favorable hinge-binding substructures, basic groups, all added up, and culminated in appreciable cytotoxicity against GBM cell line.

Protein kinase inhibitor ceritinib blocks ectonucleotidase CD39 - a promising target for cancer immunotherapy

Background

An important mechanism, by which cancer cells achieve immune escape, is the release of extracellular adenosine into their microenvironment. Adenosine activates adenosine A_2A and A_2B receptors on immune cells constituting one of the strongest immunosuppressive mediators. In addition, extracellular adenosine promotes angiogenesis, tumor cell proliferation, and metastasis. Cancer cells upregulate ectonucleotidases, most importantly CD39 and CD73, which catalyze the hydrolysis of extracellular ATP to AMP (CD39) and further to adenosine (CD73). Inhibition of CD39 is thus expected to be an effective strategy for the (immuno)therapy of cancer. However, suitable small molecule inhibitors for CD39 are not available. Our aim was to identify drug-like CD39 inhibitors and evaluate them in vitro.

Methods

We pursued a repurposing approach by screening a self-compiled collection of approved, mostly ATP-competitive protein kinase inhibitors, on human CD39. The best hit compound was further characterized and evaluated in various orthogonal assays and enzyme preparations, and on human immune and cancer cells.

Results

The tyrosine kinase inhibitor ceritinib, a potent anticancer drug used for the treatment of anaplastic lymphoma kinase (ALK)-positive metastatic non-small cell lung cancer, was found to strongly inhibit CD39 showing selectivity versus other ectonucleotidases. The drug displays a non-competitive, allosteric mechanism of CD39 inhibition exhibiting potency in the low micromolar range, which is independent of substrate (ATP) concentration. We could show that ceritinib inhibits ATP dephosphorylation in peripheral blood mononuclear cells in a dose-dependent manner, resulting in a significant increase in ATP concentrations and preventing adenosine formation from ATP. Importantly, ceritinib (1–10 µM) substantially inhibited ATP hydrolysis in triple negative breast cancer and melanoma cells with high native expression of CD39.

Conclusions

CD39 inhibition might contribute to the effects of the powerful anticancer drug ceritinib. Ceritinib is a novel CD39 inhibitor with high metabolic stability and optimized physicochemical properties; according to our knowledge, it is the first brain-permeant CD39 inhibitor. Our discovery will provide the basis (i) to develop more potent and balanced dual CD39/ALK inhibitors, and (ii) to optimize the ceritinib scaffold towards interaction with CD39 to obtain potent and selective drug-like CD39 inhibitors for future in vivo studies.

The ALK inhibitors, alectinib and ceritinib, induce ALK-independent and STAT3-dependent glioblastoma cell death

Glioblastoma (GBM) is the most common, but extremely malignant, brain tumor; thus, the development of novel therapeutic strategies for GBMs is imperative. Many tyrosine kinase inhibitors (TKIs) have been approved for various cancers, yet none has demonstrated clinical benefit against GBM. Anaplastic lymphoma kinase (ALK) is a receptor tyrosine kinase (RTK) that is confirmed only during the embryonic development period in humans. In addition, various ALK gene alterations are known to act as powerful oncogenes and therapeutic targets in various tumors. The antitumor activity of various TKIs was tested against three human GBM cell lines (U87MG, LN229, and GSC23), which expressed substantially low ALK levels; second‐generation ALK inhibitors, alectinib and ceritinib, effectively induced GBM cell death. In addition, treatment with either alectinib or ceritinib modulated the activation of various molecules downstream of RTK signaling and induced caspase‐dependent/‐independent cell death mainly by inhibiting signal transducer and activator of transcription 3 activation in human GBM cells. In addition, alectinib and ceritinib also showed antitumor activity against a U87MG cell line with acquired temozolomide resistance. Finally, oral administration of alectinib and ceritinib prolonged the survival of mice harboring intracerebral GBM xenografts compared with controls. These results suggested that treatment with the second‐generation ALK inhibitors, alectinib and ceritinib, might serve as a potent therapeutic strategy against GBM.