[Recent findings and advances in treatment of chronic myeloid leukemia].

Imatinib, the first ABL-tyrosine kinase inhibitor (TKI), was approved in 2000 for the treatment of chronic myeloid leukemia (CML). Second- and third-generation TKIs, as well as asciminib, which targets a different site of BCR-ABL1 (the myristoyl pocket), were later approved in 2022. Currently, six drugs are approved for the treatment of CML. Revisions to the clinical guidelines for hematopoietic tumors in 2023 provided new guidance on the utility of new agents as well as TKI dose reduction and treatment discontinuation. This article outlines recently reported predictions regarding TKI treatment response, the role of asciminib in the treatment of CML, and development of new agents, as well as the latest findings regarding the current state of TKI treatment discontinuation.

New benzimidazole-oxadiazole derivatives as potent VEGFR-2 inhibitors: Synthesis, anticancer evaluation, and docking study.

We report herein, the design and synthesis of benzimidazole-oxadiazole derivatives as new inhibitors for vascular endothelial growth factor receptor-2 (VEGFR-2). The designed members were assessed for their in vitro anticancer activity against three cancer cell lines and two normal cell lines; A549, MCF-7, PANC-1, hTERT-HPNE and CCD-19Lu. Compounds 4c and 4d were found to be the most effective compounds against three cancer cell lines. Compounds 4c and 4d were then tested for their in vitro VEGFR-2 inhibitory activity, safety profiles, and selectivity indices using the normal hTERT-HPNE and CCD-19Lu cell lines. It was determined that compound 4c was the most effective and safe member of the produced chemical family. Vascular endothelial growth factor A (VEGFA) immunolocalizations of compounds 4c and 4d were evaluated relative to control by VEGFA immunofluorescence staining. Compounds 4c and 4d inhibited VEGFR-2 enzyme with half-maximal inhibitory concentration values of 0.475 ± 0.021 and 0.618 ± 0.028 µM, respectively. Molecular docking of the target compounds was carried out in the active site of VEGFR-2 (Protein Data Bank: 4ASD).

Bruton's tyrosine kinase inhibitor-related cardiotoxicity: The quest for predictive biomarkers and improved risk stratification.

Ibrutinib was the first Bruton's tyrosine kinase (BTK) inhibitor approved for the treatment of patients with chronic lymphocytic leukemia (CLL). While producing durable responses and prolonging survival, roughly 20-25% of patients experience dose limiting side effects, mostly consisting of cardiovascular toxicities like severe hypertension and atrial fibrillation. While clinical predictors of BTK inhibitor-related cardiotoxicity have been proposed and may aid in risk stratification, there is no routine risk model used in clinical practice today to identify patients at highest risk. A recent study investigating genetic predictors of ibrutinib-related cardiotoxicity found that single nucleotide polymorphisms in KCNQ1 and GATA4 were significantly associated with cardiotoxic events. If replicated in larger studies, these biomarkers may improve risk stratification in combination with clinical factors. A clinicogenomic risk model may aid in identifying patients at highest risk of developing BTK inhibitor-related cardiotoxicity in which further risk mitigation strategies may be explored.

Integrated PBPK-EO modeling of osimertinib to predict plasma concentrations and intracranial EGFR engagement in patients with brain metastases.

The purpose of this study was to develop and validate a physiologically based pharmacokinetic (PBPK) model combined with an EGFR occupancy (EO) model for osimertinib (OSI) to predict plasma trough concentration (Ctrough) and the intracranial time-course of EGFR (T790M and L858R mutants) engagement in patient populations. The PBPK model was also used to investigate the key factors affecting OSI pharmacokinetics (PK) and intracranial EGFR engagement, analyze resistance to the target mutation C797S, and determine optimal dosing regimens when used alone and in drug-drug interactions (DDIs). A population PBPK-EO model of OSI was developed using physicochemical, biochemical, binding kinetic, and physiological properties, and then validated using nine clinical PK studies, observed EO study, and two clinical DDI studies. The PBPK-EO model demonstrated good consistency with observed data, with most prediction-to-observation ratios falling within the range of 0.7 to 1.3 for plasma AUC, Cmax, Ctrough and intracranial free concentration. The simulated time-course of C797S occupancy by the PBPK model was much lower than T790M and L858R occupancy, providing an explanation for OSI on-target resistance to the C797S mutation. The PBPK model identified ABCB1 CLint,u, albumin level, and EGFR expression as key factors affecting plasma Ctrough and intracranial EO for OSI. Additionally, PBPK-EO simulations indicated that the optimal dosing regimen for OSI in patients with brain metastases is either 80 mg once daily (OD) or 160 mg OD, or 40 mg or 80 mg twice daily (BID). When used concomitantly with CYP enzyme perpetrators, the PBPK-EO model suggested appropriate dosing regimens of 80 mg OD with fluvoxamine (FLUV) itraconazole (ITR) or fluvoxamine (FLUC) for co-administration and an increase to 160 mg OD with rifampicin (RIF) or efavirenz (EFA). In conclusion, the PBPK-EO model has been shown to be capable of simulating the pharmacokinetic concentration-time profiles and the time-course of EGFR engagement for OSI, as well as determining the optimum dosing in various clinical situations.

Vorolanib, sunitinib, and axitinib: A comparative study of vascular endothelial growth factor receptor inhibitors and their anti-angiogenic effects.

PURPOSE: Pathological angiogenesis and vascular instability are observed in diabetic retinopathy (DR), diabetic macular edema (DME), and wet age-related macular degeneration (wAMD). Many receptor tyrosine kinases (RTKs) including vascular endothelial growth factor receptors (VEGFRs) contribute to angiogenesis, whereas the RTK TIE2 is important for vascular stability. Pan-VEGFR tyrosine kinase inhibitors (TKIs) such as vorolanib, sunitinib, and axitinib are of therapeutic interest over current antibody treatments that target only one or two ligands. This study compared the anti-angiogenic potential of these TKIs. METHODS: A kinase HotSpot™ assay was conducted to identify TKIs inhibiting RTKs associated with angiogenesis and vascular stability. Half-maximal inhibitory concentration (IC50) for VEGFRs and TIE2 was determined for each TKI. In vitro angiogenesis inhibition was investigated using a human umbilical vein endothelial cell sprouting assay, and in vivo angiogenesis was studied using the chorioallantoic membrane assay. Melanin binding was assessed using a melanin-binding assay. Computer modeling was conducted to understand the TIE2-axitinib complex as well as interactions between vorolanib and VEGFRs. RESULTS: Vorolanib, sunitinib, and axitinib inhibited RTKs of interest in angiogenesis and exhibited pan-VEGFR inhibition. HotSpot™ assay and TIE2 IC50 values showed that only axitinib potently inhibited TIE2 (up to 89%). All three TKIs effectively inhibited angiogenesis in vitro. In vivo, TKIs were more effective at inhibiting VEGF-induced angiogenesis than the anti-VEGF antibody bevacizumab. Of the three TKIs, only sunitinib bound melanin. TKIs differ in their classification and binding to VEGFRs, which is important because type II inhibitors have greater selectivity than type I TKIs. CONCLUSIONS: Vorolanib, sunitinib, and axitinib exhibited pan-VEGFR inhibition and inhibited RTKs associated with pathological angiogenesis. Of the three TKIs, only axitinib potently inhibited TIE2 which is an undesired trait as TIE2 is essential for vascular stability. The findings support the use of vorolanib for therapeutic inhibition of angiogenesis observed in DR, DME, and wAMD.

Genome-wide in vivo CRISPR screen identifies TGFß3 as actionable biomarker of palbociclib resistance in triple negative breast cancer.

Triple negative breast cancer (TNBC) remains exceptionally challenging to treat. While CDK4/6 inhibitors have revolutionized HR + breast cancer therapy, there is limited understanding of their efficacy in TNBC and meaningful predictors of response and resistance to these drugs remain scarce. We conducted an in vivo genome-wide CRISPR screen using palbociclib as a selection pressure in TNBC. Hits were prioritized using microarray data from a large panel of breast cancer cell lines to identify top palbociclib sensitizers. Our study defines TGFß3 as an actionable determinant of palbociclib sensitivity that potentiates its anti-tumor effects. Mechanistically, we show that chronic palbociclib exposure depletes p21 levels, contributing to acquired resistance, and that TGFß3 treatment can overcome this. This study defines TGFß3 as an actionable biomarker that can be used to improve patient stratification for palbociclib treatment and exploits the synergistic interaction between CDK4/6 and TGFß3 to propose a new combinatorial treatment for TNBC.

Targeting FGFR for cancer therapy.

The FGFR signaling pathway is integral to cellular activities, including proliferation, differentiation, and survival. Dysregulation of this pathway is implicated in numerous human cancers, positioning FGFR as a prominent therapeutic target. Here, we conduct a comprehensive review of the function, signaling pathways and abnormal alterations of FGFR, as well as its role in tumorigenesis and development. Additionally, we provide an in-depth analysis of pivotal phase 2 and 3 clinical trials evaluating the performance and safety of FGFR inhibitors in oncology, thereby shedding light on the current state of clinical research in this field. Then, we highlight four drugs that have been approved for marketing by the FDA, offering insights into their molecular mechanisms and clinical achievements. Our discussion encompasses the intricate landscape of FGFR-driven tumorigenesis, current techniques for pinpointing FGFR anomalies, and clinical experiences with FGFR inhibitor regimens. Furthermore, we discuss the inherent challenges of targeting the FGFR pathway, encompassing resistance mechanisms such as activation by gatekeeper mutations, alternative pathways, and potential adverse reactions. By synthesizing the current evidence, we underscore the potential of FGFR-centric therapies to enhance patient prognosis, while emphasizing the imperative need for continued research to surmount resistance and optimize treatment modalities.

Combined use of tyrosine kinase inhibitors with PD-(L)1 blockade increased the risk of thyroid dysfunction in PD-(L)1 blockade: a prospective study.

BACKGROUND: Anti-programmed cell death-1 (ligand-1) antibody [PD-(L)1-Ab] can cause destructive thyroiditis and/or hypothyroidism. In addition, tyrosine kinase inhibitors (TKIs) frequently induce hypothyroidism. The aim of this prospective study is to examine the incidence and clinical characteristics of thyroid dysfunction induced by combination therapy of a PD-(L)1-Ab and TKI [PD-(L)1-Ab/TKI]. METHODS: A total of 757 patients treated with PD-(L)1-Ab or PD-(L)1-Ab/TKI were evaluated for anti-thyroid antibodies (ATAs) at baseline and for thyroid function for 48 weeks after treatment initiation and then observed until the last visit. RESULTS: The cumulative incidences of destructive thyroiditis [4/23 (17.4%) vs. 45/734 (6.1%) patients, p < 0.001], isolated hypothyroidism [10/23 (43.5%) vs. 29/734 (4.0%) patients, p < 0.001], and all thyroid dysfunction [14/23 (60.9%) vs. 74/734 (10.1%) patients, p < 0.001] were significantly higher in the PD-(L)1-Ab/TKI group than PD-(L)1-Ab group, respectively. All patients positive for ATAs at baseline developed thyroid dysfunction after PD-(L)1-Ab/TKI treatment, a significantly higher incidence than that in those negative for ATAs at baseline [4/4 (100%) vs. 10/19 (52.6%) patients, p = 0.026]. CONCLUSIONS: The addition of TKIs increased the risk of thyroid dysfunction induced by PD-(L)1-Ab, with the risk being higher in patients positive for baseline ATAs.

Discovery of Substituted 2-oxoquinolinylthiazolidin-4-one Analogues as Potential EGFRK Inhibitors in Lung Cancer Treatment.

PURPOSE: Cancer is the second leading cause of death globally and is responsible for an estimated 9.6 million deaths in 2018. Globally, about 1 in 6 deaths is due to cancer and the chemotherapeutic drugs available have high toxicity and have reported side effects hence, there is a need for the synthesis of novel drugs in the treatment of cancer. METHODS: The current research work dealt with the synthesis of a series of 3-(3-acetyl-2-oxoquinolin-1-(2H)-yl-2-(substitutedphenyl)thiazolidin-4-one (Va-j) derivatives and evaluation of their in-vitro anticancer activity. All the synthesized compounds were satisfactorily characterized by IR and NMR data. Compounds were further evaluated for their in-vitro anticancer activity against A-549 (lung cancer) cell lines. The in-vitro anticancer activity was based upon the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazoliumbromide (MTT) assay method. RESULTS: The synthesized compounds exhibited satisfactory anticancer properties against the A-549 cell line. The compound (VH): showed the highest potency amongst the tested derivatives against the A-549 cell line with IC50 values of 100 µg/ml respectively and was also found to be more potent than Imatinib (150 µg/ml) which was used as a standard drug. Molecular docking studies of the titled compounds (Va-j) were carried out using AutoDock Vina/PyRx software. The synthesized compounds exhibited well-conserved hydrogen bonds with one or more amino acid residues in the active pocket of the EGFRK tyrosine kinase domain (PDB 1m17). CONCLUSION: Among all the synthesized analogues, the binding affinity of the compound (Vh) was found to be higher than other synthesized derivatives and a molecular dynamics simulation study explored the stability of the docked complex system.

Integrated functional genomic screening to bypass TKI resistance in chronic myeloid leukemia.

CML is readily treatable with tyrosine kinase inhibitors (TKIs); however, resistance occurs, with the disease curable in only ∼15%-20% of patients. Using integrated functional genomics, Adnan Awad et al.1 identify agents effective against CML stem cells and describe mechanisms underlying TKI resistance.

NTRK gene fusion testing and management in lung cancer.

Neurotrophic tyrosine receptor kinase (NTRK) gene fusions are recurrent oncogenic drivers found in a variety of solid tumours, including lung cancer. Several tropomyosin receptor kinase (TRK) inhibitors have been developed to treat tumours with NTRK gene fusions. Larotrectinib and entrectinib are first-generation TRK inhibitors that have demonstrated efficacy in patients with TRK fusion lung cancers. Genomic testing is recommended for all patients with metastatic non-small cell lung cancer for optimal drug therapy selection. Multiple testing methods can be employed to identify NTRK gene fusions in the clinic and each has its own advantages and limitations. Among these assays, RNA-based next-generation sequencing (NGS) can be considered a gold standard for detecting NTRK gene fusions; however, several alternatives with minimally acceptable sensitivity and specificity are also available in areas where widespread access to NGS is unfeasible. This review highlights the importance of testing for NTRK gene fusions in lung cancer, ideally using the gold-standard method of RNA-based NGS, the various assays that are available, and treatment algorithms for patients.

EGFR and PI3K Signalling Pathways as Promising Targets on Circulating Tumour Cells from Patients with Metastatic Gastric Adenocarcinoma.

The prognosis for metastatic gastric adenocarcinoma (mGAC) remains poor. Gene alterations in receptor tyrosine kinases (RTKs) such as epidermal growth factor receptor (EGFR) and their downstream effectors including catalytic subunit alpha of the phosphatidylinositol 3-kinase (PIK3CA) are common in mGAC. Targeted RTK and phosphatidylinositol-3-kinase (PI3K) treatments have demonstrated clinical benefits in other solid tumours and are key potential targets for clinical development against mGAC given the presence of recurrent alterations in these pathways. Furthermore, combination RTK/PI3K treatments may overcome compensatory mechanisms that arise using monotherapies, leading to improved patient outcomes. Herein, we investigated RTK/PI3K single and combination drug responses against our unique human mGAC-derived PIK3CA gain-of-function mutant, human epidermal growth factor receptor 2 (HER2)-negative, EGFR-expressing circulating tumour cell line, UWG02CTC, under two- and three-dimensional culture conditions to model different stages of metastasis. UWG02CTCs were highly responsive to the PI3K p110α-subunit targeted drugs PIK-75 (IC50 = 37.0 ± 11.1 nM) or alpelisib (7.05 ± 3.7 µM). Drug sensitivities were significantly increased in 3D conditions. Compensatory MAPK/ERK pathway upregulation by PI3K/Akt suppression was overcome by combination treatment with the EGFR inhibitor gefitinib, which was strongly synergistic. PIK-75 plus gefitinib significantly impaired UWG02CTC invasion in an organotypic assay. In conclusion, UWG02CTCs are a powerful ex vivo mGAC drug responsiveness model revealing EGFR/PI3K-targeted drugs as a promising combination treatment option for HER2-negative, RAS wild-type mGAC patients.

Optimizing BTK Inhibition in Waldenström Macroglobulinemia.

Bruton tyrosine kinase (BTK) inhibitors have become a standard of care in the treatment of patients with Waldenström macroglobulinemia (WM) and are the only medications approved by the FDA to treat these patients. As more patients with WM are treated with BTK inhibitors in the United States and worldwide, it is essential to optimize this therapy by selecting the patients who are more likely to benefit from it, and by managing the unique adverse effects associated with these agents. Herein, we propose a genomic-driven approach to selecting patients with WM who are more likely to experience fast, deep, and durable responses to BTK inhibitors, and provide practical strategies for managing adverse effects, including BTK inhibitor dose reductions, switching to other BTK inhibitors, and abandoning BTK inhibitor therapy. Ongoing clinical trials are evaluating covalent and noncovalent BTK inhibitors alone and in combination, as well as BTK degraders, with exciting results, making the horizon for BTK-targeting therapies in WM bright and hopeful.

Selective but not pan-CDK inhibition abrogates 5-FU-driven tissue factor upregulation in colon cancer.

Thromboembolic events are complications in cancer patients and hypercoagulability has been linked to the tissue factor (TF) pathway, making this an attractive target. Here, we investigated the effects of chemotherapeutics and CDK inhibitors (CDKI) abemaciclib/palbociclib (CDK4/6), THZ-1 (CDK7/12/13), and dinaciclib (CDK1/2/5/9) alone and in combination regimens on TF abundance and coagulation. The human colorectal cancer (CRC) cell line HROC173 was treated with 5-FU or gemcitabine to stimulate TF expression. TF+ cells were sorted, recultured, and re-analyzed. The effect of treatment alone or in combination was assessed by functional assays. Low-dose chemotherapy induced a hypercoagulable state and significantly upregulated TF, even after reculture without treatment. Cells exhibited characteristics of epithelial-mesenchymal transition, including high expression of vimentin and mucin. Dinaciclib and THZ-1 also upregulated TF, while abemaciclib and palbociclib downregulated it. Similar results were observed in coagulation assays. The same anticoagulant activity of abemaciclib was seen after incubation with peripheral immune cells from healthy donors and CRC patients. Abemaciclib reversed 5-FU-induced TF upregulation and prolonged clotting times in second-line treatment. Effects were independent of cytotoxicity, senescence, and p27kip1 induction. TF-antibody blocking experiments confirmed the importance of TF in plasma coagulation, with Factor XII playing a minor role. Short-term abemaciclib counteracts 5-FU-induced hypercoagulation and eventually even prevents thromboembolic events.

Computational insights into allosteric inhibition of focal adhesion kinase: A combined pharmacophore modeling and molecular dynamics approach.

Focal adhesion kinase (FAK) is a non-receptor tyrosine kinase that modulates integrin and growth factor signaling pathways and is implicated in cancer cell migration, proliferation, and survival. Over the past decade various, FAK kinase, FERM, and FAT domain inhibitors have been reported and a few kinase domain inhibitors are under clinical consideration. However, few of them were identified as multikinase inhibitors. In kinase drug design selectivity is always a point of concern, to improve selectivity allosteric inhibitor development is the best choice. The current research utilized a pharmacophore modeling (PM) approach to identify novel allosteric inhibitors of FAK. The all-available allosteric inhibitor bound 3D structures with PDB ids 4EBV, 4EBW, and 4I4F were utilized for the pharmacophore modeling. The validated PM models were utilized to map a database of 770,550 compounds prepared from ZINC, EXIMED, SPECS, ASINEX, and InterBioScreen, aiming to identify potential allosteric inhibitors. The obtained compounds from screening step were forwarded to molecular docking (MD) for the prediction of binding orientation inside the allosteric site and the results were evaluated with the known FAK allosteric inhibitor (REF). Finally, 14 FAK-inhibitor complexes were selected from the docking study and were studied under molecular dynamics simulations (MDS) for 500 ns. The complexes were ranked according to binding free energy (BFE) and those demonstrated higher affinity for allosteric site of FAK than REF inhibitors were selected. The selected complexes were further analyzed for intermolecular interactions and finally, three potential allosteric inhibitor candidates for the inhibition of FAK protein were identified. We believe that identified scaffolds may help in drug development against FAK as an anticancer agent.

[Advances of Molecular Targeted Therapy in EGFR-mutated Squamous Cell Lung Cancer].

Non-small cell lung cancer (NSCLC) is a prevalent tumour type in our country, with lung squamous carcinoma being a commonly observed NSCLC subtype besides lung adenocarcinoma. Epidermal growth factor receptor (EGFR) is a significant driver gene in lung cancer, and EGFR mutation frequency is considerably lower in lung squamous carcinoma in comparison to lung adenocarcinoma. Although targeted therapy against EGFR has demonstrated significant advancements in lung adenocarcinoma, while progress in lung squamous carcinoma has been relatively sluggish. This paper reviews recent studies on molecular targeted therapy for EGFR-mutated lung squamous carcinoma and summarises the efficacy of EGFR-tyrosine kinase inhibitors (TKIs) in treating squamous carcinoma of the lung, in order to provide a reference for treating patients with EGFR-mutated squamous carcinoma of the lung.
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Extracellular vesicles promote migration despite BRAF inhibitor treatment in malignant melanoma cells.

Extracellular vesicles (EVs) constitute a vital component of intercellular communication, exerting significant influence on metastasis formation and drug resistance mechanisms. Malignant melanoma (MM) is one of the deadliest forms of skin cancers, because of its high metastatic potential and often acquired resistance to oncotherapies. The prevalence of BRAF mutations in MM underscores the importance of BRAF-targeted therapies, such as vemurafenib and dabrafenib, alone or in combination with the MEK inhibitor, trametinib. This study aimed to elucidate the involvement of EVs in MM progression and ascertain whether EV-mediated metastasis promotion persists during single agent BRAF (vemurafenib, dabrafenib), or MEK (trametinib) and combined BRAF/MEK (dabrafenib/trametinib) inhibition.Using five pairs of syngeneic melanoma cell lines, we assessed the impact of EVs - isolated from their respective supernatants - on melanoma cell proliferation and migration. Cell viability and spheroid growth assays were employed to evaluate proliferation, while migration was analyzed through mean squared displacement (MSD) and total traveled distance (TTD) measurements derived from video microscopy and single-cell tracking.Our results indicate that while EV treatments had remarkable promoting effect on cell migration, they exerted only a modest effect on cell proliferation and spheroid growth. Notably, EVs demonstrated the ability to mitigate the inhibitory effects of BRAF inhibitors, albeit they were ineffective against a MEK inhibitor and the combination of BRAF/MEK inhibitors. In summary, our findings contribute to the understanding of the intricate role played by EVs in tumor progression, metastasis, and drug resistance in MM.

Evaluating zanubrutinib for the treatment of adults with chronic lymphocytic leukemia or small lymphocytic lymphoma.

INTRODUCTION: This review evaluates zanubrutinib as a treatment option for adults with chronic lymphocytic leukemia (CLL)/small lymphocytic lymphoma (SLL). Zanubrutinib, a covalent BTK (Bruton's tyrosine kinase) inhibitor, was recently approved by the US FDA based in part on head-to-head data demonstrating improved efficacy and safety compared to ibrutinib. AREAS COVERED: The review discusses the efficacy, safety, and comparative advantages of zanubrutinib, highlighting its safety profile compared to other BTK inhibitors. It also addresses the unmet needs of current therapies in CLL/SLL and provides an overview of competitor compounds and ongoing research in BTK inhibition. EXPERT OPINION: Zanubrutinib, the first BTK inhibitor to demonstrate superior efficacy and safety compared to another BTK inhibitor in CLL, is likely to be widely adopted due to its high-quality data and ease of use. Looking ahead, pirtobrutinib, a novel non-covalent BTK inhibitor, has shown promise in heavily pretreated CLL patients, including those unresponsive to covalent inhibitors, with ongoing phase 3 trials comparing it against ibrutinib. The field is also exploring time-limited therapies like the combination of ibrutinib and venetoclax, with ongoing trials evaluating different combinations to optimize efficacy and minimize toxicity, indicating a promising future for combination therapies in CLL treatment.