Triple Angiokinase Inhibitor Nintedanib Directly Inhibits Tumor Cell Growth and Induces Tumor Shrinkage via Blocking Oncogenic Receptor Tyrosine Kinases

Effect and mechanism of Nintedanib on acute and chronic radiation-induced lung injury in mice

OBJECTIVE

To investigate the efficacy of Nintedanib in treating acute and chronic radiation-induced lung injury and its mechanism of action.

METHODS

A radiation-induced lung injury model was established in mice using 6MV X-rays at 18Gy to irradiate the lungs. The mice were randomly divided into four groups: control group, radiation therapy group, low-dosage Nintedanib + radiation therapy group, and high dosage Nintedanib + radiation therapy group. The mice were euthanized on day 14 and 3 months post-radiation to observe changes in acute and chronic inflammation and the expression of related proteins.

RESULTS

Compared to the radiation therapy group, the low and high-dosage Nintedanib groups showed varying degrees of improvement in mental state, responsiveness, food and water intake, and fur condition. During the acute inflammatory phase, HE staining revealed inflammatory changes in the lung tissues of both Nintedanib groups, but the pathology was less severe than in the radiation group, with the high-dosage group showing more significant reduction. Serum levels of IL-6, TNF-α and TGF-β1 were significantly reduced (P < 0.05), suggesting that Nintedanib can decrease the expression of serum inflammatory factors. The percentage of Smad2-positive area in the low and high-dosage Nintedanib groups was (7.395 ± 0.90)% and (5.577 ± 1.56)%, respectively, both significantly lower than the radiation group (P < 0.05). At 3 months post-radiation, Masson's trichrome staining showed that the Ashcroft score in the Nintedanib groups was significantly lower than in the radiation group (P < 0.05). There were statistically significant differences between the low and high-dosage groups in the percentage of Smad2 and αSMA-positive areas and the levels of serum TGF-β1 (all P < 0.05), and both were significantly lower compared to the radiation group (P < 0.05).

CONCLUSION

(1) Nintedanib can improve the general condition of mice with acute and chronic radiation-induced lung injury and reduce pathological damage to lung tissue. (2) Nintedanib may exert a protective effect on mice with acute and chronic radiation-induced lung injury by downregulating the TGF-β1/Smad2 signaling pathway, thereby inhibiting inflammatory and fibrotic responses.

The tumor microenvironment: shaping cancer progression and treatment response

The tumor microenvironment (TME) plays a crucial role in cancer progression and treatment response. It comprises a complex network of stromal cells, immune cells, extracellular matrix, and blood vessels, all of which interact with cancer cells and influence tumor behaviour. This review article provides an in-depth examination of the TME, focusing on stromal cells, blood vessels, signaling molecules, and ECM, along with commonly available therapeutic compounds that target these components. Moreover, we explore the TME as a novel strategy for discovering new anti-tumor drugs. The dynamic and adaptive nature of the TME offers opportunities for targeting specific cellular interactions and signaling pathways. We discuss emerging approaches, such as combination therapies that simultaneously target cancer cells and modulate the TME. Finally, we address the challenges and future prospects in targeting the TME. Overcoming drug resistance, improving drug delivery, and identifying new therapeutic targets within the TME are among the challenges discussed. We also highlight the potential of personalized medicine and the integration of emerging technologies, such as immunotherapy and nanotechnology, in TME-targeted therapies. This comprehensive review provides insights into the TME and its therapeutic implications. Understanding the TME's complexity and targeting its components offer promising avenues for the development of novel anti-tumor therapies and improved patient outcomes.

Design and synthesis of antiproliferative 2-oxoindolin-3-ylidenes incorporating urea function with potential VEGFR-2 inhibitory properties

Targeted therapy is preferable over other therapeutics due to its limitation of drawbacks and better pharmaceutical outcomes. VEGF and its receptors have been observed to be hyper-activated in many cancer types and are considered promising targets for assigning anticancer agents. The current study is directed towards synthesis of novel antiproliferative 2-oxoindolin-3-ylidenes incorporating urea function with VEGFR-2 properties. The targeted agents were obtained through a two-step reaction. Addition of the appropriate 1-(acetylphenyl)-3-phenylurea 9a,b to the corresponding isatin 10a-f in ethanol containing a quantitative amount of Et2NH followed by acidic dehydration (AcOH/HCl) afforded the targeted agents 12a-j. Promising antiproliferation properties (MTT assay) were observed for most of the synthesized agents against HCT116 (colon), MCF7 (breast) and PaCa2 (pancreatic) cancer cell lines relative to sunitinib. VEGFR-2 inhibitory properties are consistent with the antiproliferation properties exhibited against the tested cell lines. Compound 12b (R = 4-NHCONHPh, R' = H; % inhibition = 87.2) is the most promising/potent anti-VEGFR-2 agent synthesized with activity close to that of sunitinib (% inhibition = 89.4) at 10 μM. Molecular docking studies (PDB: 3WZE and 3AGD) support the antiproliferation effects against cancer cell lines tested with VEGFR-2 inhibitory properties. The results are consistent with collaboration of the pharmacophores considered (2-oxoindolyl heterocycle and urea) in improving the bio-properties.

A non-interventional biomarker study in patients with adenocarcinoma of the lung treated with nintedanib plus docetaxel following progression on chemotherapy and/or immunotherapy: LUME-BioNIS

Background

Anti-angiogenic agents, such as nintedanib and ramucirumab, when combined with docetaxel, are subsequent treatment options in patients with non-small cell lung cancer (NSCLC) who have failed on first-line chemotherapy or immunochemotherapy. However, to date, there are no validated predictive biomarkers for efficacy of anti-angiogenic therapies in this setting. The aim of this study was to explore whether genetic or genomic markers, alone or combined with clinical covariates, could be used to predict overall survival (OS) in patients with NSCLC who are eligible for treatment with nintedanib plus docetaxel.

Methods

LUME-BioNIS (NCT02671422) was a prospective, non-interventional study that assessed the efficacy and safety of nintedanib plus docetaxel in patients with relapsed/refractory NSCLC. The primary outcome was OS in relation to exploratory molecular biomarkers, alone or in combination with clinical covariates. Exploratory multivariate and univariate analyses were undertaken on putative biomarkers including clinical variables, somatic mutations, gene expression, immunological, and proliferation markers. Sub-analyses in patients with prior immunotherapy were performed.

Results

Of 260 enrolled patients, most patients received nintedanib plus docetaxel in the second-line (68.8%) or third-line (25.8%). After a median follow-up of 19.7 months, median OS was 8.1 months (95% confidence interval: 7.1-9.5). Univariate subgroup analysis indicated that the presence of liver/adrenal metastases, Eastern Cooperative Oncology Group performance status (ECOG PS) ≥1, time since start of first-line therapy (<9 months), and response to first-line therapy had potential prognostic significance for OS. In multivariate analysis, the presence of brain/liver metastases and the presence of >2 metastatic sites at baseline were associated with OS. In univariate analyses in patients with prior immunotherapy, RNA expression levels of genes involved in cell proliferation, DNA damage repair, interferon signaling, and abundance of neutrophils had potential prognostic significance for OS.

Conclusions

Nintedanib plus docetaxel had promising activity and manageable safety in a real-world clinical setting. No new predictive biomarkers were identified to help select patients who may particularly benefit from anti-angiogenic therapy.

Fibroblast growth factor therapies in biliary tract cancers: current and future state

INTRODUCTION

Cholangiocarcinoma is the rare and aggressive tumor with poor prognosis and limited therapeutic options. Recently, there have been promising developments in molecular targeted therapies for patients following the progression of first-line chemotherapy and immunotherapy combinations. Dysregulation of fibroblast Growth Factor Receptor (FGFR) signaling is significantly associated with tumorigenesis of intrahepatic cholangiocarcinoma and has been identified as a targetable alteration. This was possible through the discovery of crucial insights into the biochemical mechanisms and pathophysiology of the FGFR pathway.

AREAS COVERED

This review summarizes the current state of FGFR targeted therapies, mechanisms of resistance, and future directions for FGFR-targeted therapies in patients with cholangiocarcinoma.

EXPERT OPINION

Currently, pemigatinib and futibatinib are FDA approved FGFR-targeted therapies that have demonstrated remarkable responses. However, there is still a significant proportion of patients whose disease remains intrinsically resistant to treatment and most patients eventually develop secondary resistance after an initial response. Additionally, unique side effects of FGFR inhibitors may limit their efficacy in clinical practice and can have detrimental effects on quality of life. Several novel FGFR inhibitors are currently being investigated to overcome resistance mechanisms and reduce toxicities.

Safety and Tolerability of Nintedanib in Patients with Fibrosing Interstitial Lung Diseases: Post-marketing Data

INTRODUCTION

Nintedanib is approved for the treatment of idiopathic pulmonary fibrosis (IPF), other forms of progressive pulmonary fibrosis (PPF), and systemic sclerosis-associated interstitial lung disease (ILD). We present global post-marketing safety data for nintedanib in these fibrosing ILDs.

METHODS

Data on adverse events in patients with fibrosing ILDs who were treated with nintedanib were collected via spontaneous reporting and solicited reporting in various studies (excluding clinical trials). Data were collected from 15 October 2014 (first regulatory approval) to 15 October 2023. Adverse events were coded using the Medical Dictionary for Regulatory Activities. Cumulative exposure to nintedanib was estimated using sales data.

RESULTS

Cumulative exposure to nintedanib was 380,557 patient-years. Diarrhoea was reported at a rate of 227.5 per 1000 patient-years. Only 2.6% of diarrhoea events were reported as serious. Of 39,788 (33.6%) diarrhoea events with a known time to onset, almost 60% occurred within the first 3 months of treatment. The rate of serious liver enzyme and bilirubin elevations (including drug-induced liver injury) was 4.0 per 1000 patient-years. Bleeding was reported at a rate of 24.2 per 1000 patient-years. Most (81.3%) bleeding events were non-serious. The rates of myocardial infarction, ischaemic stroke, and venous thromboembolism were 3.3, 3.3, and 2.0 per 1000 patient-years, respectively. Gastrointestinal perforation was reported at a rate of 0.9 per 1000 patient-years.

CONCLUSION

Post-marketing safety data on established and potential adverse events associated with nintedanib in patients with fibrosing ILDs, collected over 9 years, demonstrated a safety profile that was similar to that established in clinical trials and provided in the product labels. Education of patients about the adverse events that may be associated with nintedanib, and the effective management of adverse events when they occur, is important to minimise the impact of adverse events and help patients remain on treatment.

Oxindole-benzothiazole hybrids as CDK2 inhibitors and anticancer agents: design, synthesis and biological evaluation

In the current study, molecular hybridization between the oxindole core and benzothiazole system through an acetohydrazide moiety was accomplished for the design of a new series of oxindole-benzothiazole hybrids 9a-r targeting CDK2 for cancer therapy. The afforded hybrids displayed promising growth inhibitory activity on NCI cancer cell lines at 10 µM. Compound 9o displayed mean GI% = 55.91%. Based on the potent activity of 9o, it was further assessed for its cytotoxic activity at five dose level and it demonstrated GI50 reaching 2.02 µM. Analysis of the cell cycle of the prostate cancer cell line DU145 after treatment with 9o confirmed its ability to arrest its cell cycle at the G1 phase. Moreover, 9o proved its ability to potentiate the apoptosis and necrosis of the same cell line. Furthermore, the oxindole-benzothiazole hybrids 9b, 9f and 9o showed IC50 = 0.70, 0.20 and 0.21 µM, respectively on CDK2. Besides, molecular docking simulation of the synthesized oxindole-benzothiazole hybrid 9o proved the expected binding mode which involves the accommodation of the oxindole moiety in the ATP binding pocket where it is involved in hydrogen bonding and hydrophobic interactions with the essential amino acids in the hinge region while the benzothiazole moiety is oriented toward the solvent region. Investigation of the physicochemical properties of the hybrids 9a-r highlights their acceptable ADME properties that can be somewhat developed for the discovery of new anticancer agents.

Exploring the top 30 drugs associated with drug-induced constipation based on the FDA adverse event reporting system

Objective

This project aims to identify the top 30 drugs most commonly associated with constipation and their signal values within the FDA Adverse Event Reporting System database.

Methods

We extracted adverse drug events (ADEs) related to constipation from the FAERS database spanning from January 1, 2004, to September 30, 2023. We compiled the 30 most frequently reported drugs based on the frequency of constipation events. We employed signal detection methodologies to ascertain whether these drugs elicited significant signals, including reporting odds ratio, proportional reporting ratio, multi-item gamma Poisson shrinker, and information component given by the Bayesian confidence propagation neural network. Furthermore, we conducted a time-to-onset (TTO) analysis for drugs generating significant signals using the medians, quartiles, and the Weibull shape parameter test.

Results

We extracted a total of 50, 659, 288 ADEs, among which 169,897 (0.34%) were related to constipation. We selected and ranked the top 30 drugs. The drug with the highest ranking was lenalidomide (7,730 cases, 4.55%), with the most prevalent drug class being antineoplastic and immunomodulating agents. Signal detection was performed for the 30 drugs, with constipation risk signals identified for 26 of them. Among the 26 drugs, 22 exhibited constipation signals consistent with those listed on the FDA-approved drug labels. However, four drugs (orlistat, nintedanib, palbociclib, and dimethyl fumarate) presented an unexpected risk of constipation. Ranked by signal values, sevelamer carbonate emerged as the drug with the strongest risk signal [reporting odds ratio (95% CI): 115.51 (110.14, 121.15); PRR (χ2): 83.78 (191,709.73); EBGM (EB05): 82.63 (79.4); IC (IC025): 6.37 (4.70)]. A TTO analysis was conducted for the 26 drugs that generated risk signals, revealing that all drugs exhibited an early failure type. The median TTO for orlistat was 3 days, the shortest of all the drugs, while the median TTO for clozapine was 1,065 days, the longest of all the drugs.

Conclusion

Our study provides a list of drugs potentially associated with drug-induced constipation (DIC). This could potentially inform clinicians about some alternative medications to consider when managing secondary causes of constipation or caring for patients prone to DIC, thereby reducing the incidence and mortality associated with DIC.

Accelerated Linear Growth during Erdafitinib Treatment: An FGFR-Related, but Growth Factor and Sex Steroid-Independent Mechanism?

INTRODUCTION

Growth acceleration during postnatal growth only occurs during puberty as a physiological event and during catch-up growth mediated by growth-promoting therapies in growth disorders. Here we report on novel observations of skeletal symptoms during treatment with erdafitinib, a tyrosine kinase inhibitor (TKI) prescribed on the basis of a compassionate-use program.

METHODS

Analysis of anthropometric, biochemical, clinical, and radiographic data of patients with CNS tumors who revealed an unanticipated growth spurt with initiation of therapy with erdafitinib was performed retrospectively.

RESULTS

Linear growth acceleration was independent of sex steroids and IGF1 levels, which is especially remarkable in the context of heavily pretreated pediatric neuro-oncology patients with severe growth impairment before initiation of therapy. Growth acceleration was accompanied by a distinct widening of the growth plate and enhanced metaphyseal mineralization shortly after the start of TKI therapy.

CONCLUSIONS

While targeted therapies including TKIs have become an essential part of adult cancer treatment, applications in children are still limited. Off-target effects specific to the pediatric population have been observed in various organ systems; however, knowledge about the effect of TKIs on the growing skeleton is scarce. Treatment with erdafitinib inhibits FGFR3-mediated effects and thus represents a very logical hypothetical framework of growth factor and sex steroid-independent growth acceleration.

Indole Compounds in Oncology: Therapeutic Potential and Mechanistic Insights

Cancer remains a formidable global health challenge, with current treatment modalities such as chemotherapy, radiotherapy, surgery, and targeted therapy often hindered by low efficacy and adverse side effects. The indole scaffold, a prominent heterocyclic structure, has emerged as a promising candidate in the fight against cancer. This review consolidates recent advancements in developing natural and synthetic indolyl analogs, highlighting their antiproliferative activities against various cancer types over the past five years. These analogs are categorized based on their efficacy against common cancer types, supported by biochemical assays demonstrating their antiproliferative properties. In this review, emphasis is placed on elucidating the mechanisms of action of these compounds. Given the limitations of conventional cancer therapies, developing targeted therapeutics with enhanced selectivity and reduced side effects remains a critical focus in oncological research.

Nintedanib combined with immunosuppressive agents improves forced vital capacity in connective tissue disease-associated PF-ILD: a single-center study

BACKGROUND

In 2020, Nintedanib (NTB), a tyrosine kinase inhibitor, was the first drug approved worldwide for treating progressive fibrosing interstitial lung disease (PF-ILD). This study evaluated the efficacy and safety of NTB in Japanese patients with CTD-associated PF-ILD in a real-world setting, as there are few reports on this topic. We also evaluated the efficacy and safety of combination therapy with NTB and immunosuppressive agents (IS).

METHODS

CTD-associated PF-ILD patients receiving NTB at our institution were included in this retrospective study. To evaluate the efficacy and safety of NTB, we investigated changes in forced vital capacity (FVC) (%), diffusing capacity for carbon monoxide (DLCO) (%), monthly change in FVC (%/month), serum Krebs von den Lungen-6 (KL-6) levels (U/mL) before and after NTB treatment, and adverse events (AEs) during NTB treatment. Moreover, to evaluate the efficacy of the NTB + IS combination therapy, we divided the patients into two groups: one received only NTB (NTB group), and the other received both NTB and IS (NTB + IS group) following the diagnosis of CTD-associated PF-ILD. We analyzed the differences in the changes of these variables between the two groups.

RESULTS

Twenty-six patients with CTD-associated PF-ILD were included. After NTB treatment, there were no significant deteriorations in FVC (%) and DLCO (%), while the monthly change in FVC (%/month) significantly increased (p < 0.001). The changes in FVC (%) and the monthly change in FVC (%/month) were significantly greater in the NTB + IS group than in the NTB group. Following NTB treatment, the mean serum KL-6 levels significantly decreased (p < 0.001). AEs associated with NTB in this study were similar to those in previous clinical trials, and there was no significant difference in the incidence of AEs between the two groups.

CONCLUSIONS

This study demonstrates that NTB is an effective medication for slowing the progression of CTD-associated PF-ILD in real-world settings. NTB + IS combination therapy for CTD-associated PF-ILD may be more effective than NTB alone in slowing the progression of CTD-associated PF-ILD.

Benzimidazole-oxindole hybrids as multi-kinase inhibitors targeting melanoma

In the current study, a series of benzimidazole-oxindole conjugates 8a-t were designed and synthesized as type II multi-kinase inhibitors. They exhibited moderate to potent inhibitory activity against BRAFWT up to 99.61 % at 10 µM. Notably, compounds 8e, 8k, 8n and 8s demonstrated the most promising activity, with 99.44 to 99.61 % inhibition. Further evaluation revealed that 8e, 8k, 8n and 8s exhibit moderate to potent inhibitory effects on the kinases BRAFV600E, VEGFR-2, and FGFR-1. Additionally, compounds 8a-t were screened for their cytotoxicity by the NCI, and several compounds showed significant growth inhibition in diverse cancer cell lines. Compound 8e stood out with a GI50 range of 1.23 - 3.38 µM on melanoma cell lines. Encouraged by its efficacy, it was further investigated for its antitumor activity and mechanism of action, using sorafenib as a reference standard. The hybrid compound 8e exhibited potent cellular-level suppression of BRAFWT, VEGFR-2, and FGFR-1 in A375 cell line, surpassing the effects of sorafenib. In vivo studies demonstrate that 8e significantly inhibits the growth of B16F10 tumors in mice, leading to increased survival rates and histopathological tumor regression. Furthermore, 8e reduces angiogenesis markers, mRNA expression levels of VEGFR-2 and FGFR-1, and production of growth factors. It also downregulated Notch1 protein expression and decreased TGF-β1 production. Molecular docking simulations suggest that 8e binds as a promising type II kinase inhibitor in the target kinases interacting with the key regions in their kinase domain.

FGFR-targeted therapeutics: clinical activity, mechanisms of resistance and new directions

Fibroblast growth factor (FGF) signalling via FGF receptors (FGFR1-4) orchestrates fetal development and contributes to tissue and whole-body homeostasis, but can also promote tumorigenesis. Various agents, including pan-FGFR inhibitors (erdafitinib and futibatinib), FGFR1/2/3 inhibitors (infigratinib and pemigatinib), as well as a range of more-specific agents, have been developed and several have entered clinical use. Erdafitinib is approved for patients with urothelial carcinoma harbouring FGFR2/3 alterations, and futibatinib and pemigatinib are approved for patients with cholangiocarcinoma harbouring FGFR2 fusions and/or rearrangements. Clinical benefit from these agents is in part limited by hyperphosphataemia owing to off-target inhibition of FGFR1 as well as the emergence of resistance mutations in FGFR genes, activation of bypass signalling pathways, concurrent TP53 alterations and possibly epithelial-mesenchymal transition-related isoform switching. The next generation of small-molecule inhibitors, such as lirafugratinib and LOXO-435, and the FGFR2-specific antibody bemarituzumab are expected to have a reduced risk of hyperphosphataemia and the ability to overcome certain resistance mutations. In this Review, we describe the development and current clinical role of FGFR inhibitors and provide perspective on future research directions including expansion of the therapeutic indications for use of FGFR inhibitors, combination of these agents with immune-checkpoint inhibitors and the application of novel technologies, such as artificial intelligence.

Discoidin domain receptor 2 signaling through PIK3C2α in fibroblasts promotes lung fibrosis

Pulmonary fibrosis, especially idiopathic pulmonary fibrosis (IPF), portends significant morbidity and mortality, and current therapeutic options are suboptimal. We have previously shown that type I collagen signaling through discoidin domain receptor 2 (DDR2), a receptor tyrosine kinase expressed by fibroblasts, is critical for the regulation of fibroblast apoptosis and progressive fibrosis. However, the downstream signaling pathways for DDR2 remain poorly defined and could also be attractive potential targets for therapy. A recent phosphoproteomic approach indicated that PIK3C2α, a poorly studied member of the PI3 kinase family, could be a downstream mediator of DDR2 signaling. We hypothesized that collagen I/DDR2 signaling through PIK3C2α regulates fibroblast activity during progressive fibrosis. To test this hypothesis, we found that primary murine fibroblasts and IPF-derived fibroblasts stimulated with endogenous or exogenous type I collagen led to the formation of a DDR2/PIK3C2α complex, resulting in phosphorylation of PIK3C2α. Fibroblasts treated with an inhibitor of PIK3C2α or with deletion of PIK3C2α had fewer markers of activation after stimulation with TGFβ and more apoptosis after stimulation with a Fas-activating antibody. Finally, mice with fibroblast-specific deletion of PIK3C2α had less fibrosis after bleomycin treatment than did littermate control mice with intact expression of PIK3Cα. Collectively, these data support the notion that collagen/DDR2/PIK3C2α signaling is critical for fibroblast function during progressive fibrosis, making this pathway a potential target for antifibrotic therapy. © 2024 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of The Pathological Society of Great Britain and Ireland.

Antineoplastic indole-containing compounds with potential VEGFR inhibitory properties

Cancer is one of the most significant health challenges worldwide. Various techniques, tools and therapeutics/materials have been developed in the last few decades for the treatment of cancer, together with great interest, funding and efforts from the scientific society. However, all the reported studies and efforts seem insufficient to combat the various types of cancer, especially the advanced ones. The overexpression of tyrosine kinases is associated with cancer proliferation and/or metastasis. VEGF, an important category of tyrosine kinases, and its receptors (VEGFR) are hyper-activated in different cancers. Accordingly, they are known as important factors in the angiogenesis of different tumors and are considered in the development of effective therapeutic approaches for controlling many types of cancer. In this case, targeted therapeutic approaches are preferable to the traditional non-selective approaches to minimize the side effects and drawbacks associated with treatment. Several indole-containing compounds have been identified as effective agents against VEGFR. Herein, we present a summary of the recent indolyl analogs reported within the last decade (2012-2023) with potential antineoplastic and VEGFR inhibitory properties. The most important drugs, natural products, synthesized potent compounds and promising hits/leads are highlighted. Indoles functionalized and conjugated with various heterocycles beside spiroindoles are also considered.

PBRM1 loss is associated with increased sensitivity to MCL1 and CDK9 inhibition in clear cell renal cancer

MCL1 is a member of the BCL2 family of apoptosis regulators, which play a critical role in promoting cancer survival and drug resistance. We previously described PRT1419, a potent, MCL1 inhibitor with anti-tumor efficacy in various solid and hematologic malignancies. To identify novel biomarkers that predict sensitivity to MCL1 inhibition, we conducted a gene essentiality analysis using gene dependency data generated from CRISPR/Cas9 cell viability screens. We observed that clear cell renal cancer (ccRCC) cell lines with damaging PBRM1 mutations displayed a strong dependency on MCL1. PBRM1 (BAF180), is a chromatin-targeting subunit of mammalian pBAF complexes. PBRM1 is frequently altered in various cancers particularly ccRCC with ~40% of tumors harboring damaging PBRM1 alterations. We observed potent inhibition of tumor growth and induction of apoptosis by PRT1419 in various preclinical models of PBRM1-mutant ccRCC but not PBRM1-WT. Depletion of PBRM1 in PBRM1-WT ccRCC cell lines induced sensitivity to PRT1419. Mechanistically, PBRM1 depletion coincided with increased expression of pro-apoptotic factors, priming cells for caspase-mediated apoptosis following MCL1 inhibition. Increased MCL1 activity has been described as a resistance mechanism to Sunitinib and Everolimus, two approved agents for ccRCC. PRT1419 synergized with both agents to potently inhibit tumor growth in PBRM1-loss ccRCC. PRT2527, a potent CDK9 inhibitor which depletes MCL1, was similarly efficacious in monotherapy and in combination with Sunitinib in PBRM1-loss cells. Taken together, these findings suggest PBRM1 loss is associated with MCL1i sensitivity in ccRCC and provide rationale for the evaluation of PRT1419 and PRT2527 for the treatment for PBRM1-deficient ccRCC.

Anti-fibrotic effects of nintedanib on lung fibroblasts derived from patients with Progressive Fibrosing Interstitial Lung Diseases (PF-ILDs)

The tyrosine kinase inhibitor nintedanib has been recently approved for the treatment of Interstitial Lung Diseases (ILDs) that manifest a progressive fibrosis phenotype other than Idiopathic pulmonary Fibrosis (IPF). Nintedanib reduces the development of lung fibrosis in various animal models resembling features of PF-ILD and in vitro, it inhibits the fibrosing phenotype of human lung fibroblasts (HLFs) isolated from patients with IPF. To get insight on the cellular and molecular mechanisms that drive the clinical efficiency of nintedanib in patients with non-IPF PF-ILD, we investigated its effects on the fibrosing functions of HLFs derived from patients with PF-hypersensitivity pneumonitis (PF-HP, n = 7), PF-sarcoidosis (n = 5) and pleuroparenchymal fibroelastosis (PPFE, n = 4). HLFs were treated with nintedanib (10 nM-1 μM) and then stimulated with PDGF-BB (25-50 ng/ml) or TGF-β1 (1 ng/ml) for 24-72 h to assess proliferation and migration or differentiation. At nanomolar concentrations, nintedanib reduced the levels of PDGF receptor and ERK1/2 phosphorylation, the proliferation and the migration of PF-HP, PF-sarcoidosis and PPFE HLFs stimulated with PDGF-BB. Moreover, nintedanib also attenuates the myofibroblastic differentiation driven by TGF-β1 but only when it is used at 1 μM. The drug reduced the phosphorylation of SMAD2/3 and decreased the induction of collagen, fibronectin and α-smooth muscle actin expression induced by TGF-β1. In conclusion, our results demonstrate that nintedanib counteracts fundamental fibrosing functions of lung fibroblasts derived from patients with PF-HP, PF-sarcoidosis and PPFE, at concentrations previously reported to inhibit control and IPF HLFs. Such effects may contribute to its clinical benefit in patients suffering from these irreversible ILDs.

Fibroblast Activation Protein Alpha (FAPα) in Fibrosis: Beyond a Perspective Marker for Activated Stromal Cells?

The development of tissue fibrosis is a complex process involving the interaction of multiple cell types, which makes the search for antifibrotic agents rather challenging. So far, myofibroblasts have been considered the key cell type that mediated the development of fibrosis and thus was the main target for therapy. However, current strategies aimed at inhibiting myofibroblast function or eliminating them fail to demonstrate sufficient effectiveness in clinical practice. Therefore, today, there is an unmet need to search for more reliable cellular targets to contribute to fibrosis resolution or the inhibition of its progression. Activated stromal cells, capable of active proliferation and invasive growth into healthy tissue, appear to be such a target population due to their more accessible localization in the tissue and their high susceptibility to various regulatory signals. This subpopulation is marked by fibroblast activation protein alpha (FAPα). For a long time, FAPα was considered exclusively a marker of cancer-associated fibroblasts. However, accumulating data are emerging on the diverse functions of FAPα, which suggests that this protein is not only a marker but also plays an important role in fibrosis development and progression. This review aims to summarize the current data on the expression, regulation, and function of FAPα regarding fibrosis development and identify promising advances in the area.

Inhibition of discoidin domain receptor 2 reveals kinase-dependent and kinase-independent functions in regulating fibroblast activity

Progressive pulmonary fibrosis is a devastating condition and current treatment is suboptimal. There has been considerable interest in the role of tyrosine kinase signaling as mediators of pro- and antifibrotic processes. Nintedanib is a nonspecific tyrosine kinase that has been shown to have therapeutic benefit in lung fibrosis. However, the precise mechanism of action remains unclear because nintedanib inhibits several tyrosine kinases, which are often expressed on multiple cell types with different activities during fibrosis. Discoidin domain receptor 2 (DDR2) has been suggested as a potential target of nintedanib. DDR2 is a receptor tyrosine kinase that is activated by fibrillar collagens such as type I collagen. DDR2 is primarily expressed by fibroblasts. The effectiveness of specifically targeting DDR2 signaling during fibrosis remains undefined. In the present study, we show that nintedanib acts as a direct and indirect inhibitor of DDR2. We then utilize a novel allosteric inhibitor of DDR2, WRG-28, which blocks ligand binding and activation of DDR2. We find that WRG-28 augments fibroblast apoptosis and attenuates fibrosis. Finally, we show that fibroblast type I collagen autocrine signaling is regulated by DDR2 through both kinase-dependent and kinase-independent functions of DDR2. These findings highlight the importance of type I collagen autocrine signaling by fibroblasts during fibrosis and demonstrate that DDR2 has a central role in this pathway making it a potential therapeutic target.NEW & NOTEWORTHY Type I collagen is a major component of fibrosis and can signal through cell surface receptors such as discoidin domain receptor 2 (DDR2). DDR2 activation can lead to further collagen deposition by fibroblasts setting up a profibrotic positive feedback loop. In this report, we find that inhibition of DDR2 with nintedanib or a specific DDR2 inhibitor, WRG-28, can disrupt this cycle and prevent fibrosis through augmented fibroblast apoptosis and inhibited activation.

Emerging roles of tyrosine kinases in hepatic inflammatory diseases and therapeutic opportunities

Inflammation has been convicted of causing and worsening many liver diseases like acute liver failure, fibrosis, cirrhosis, fatty liver and liver cancer. Pattern recognition receptors (PRRs) like TLRs 4 and 9 localized on resident or recruited immune cells are well known cellular detectors of pathogen and damage-associated molecular patterns (PAMPs/DAMPs). Stimulation of these receptors generates the sterile and non-sterile inflammatory responses in the liver. When these responses are repeated, there will be a sustained liver injury that may progress to fibrosis and its outcomes. Crosstalk between inflammatory/fibrogenic-dependent streams and certain tyrosine kinases (TKs) has recently evolved in the context of hepatic diseases. Because of TKs increasing importance, their role should be elucidated to highlight effective approaches to manage the diverse liver disorders. This review will give a brief overview of types and functions of some TKs like BTK, JAKs, Syk, PI3K, Src and c-Abl, as well as receptors for TAM, PDGF, EGF, VEGF and HGF. It will then move to discuss the roles of these TKs in the regulation of the proinflammatory, fibrogenic and tumorigenic responses in the liver. Lastly, the therapeutic opportunities for targeting TKs in hepatic inflammatory disorders will be addressed. Overall, this review sheds light on the diverse TKs that have substantial roles in hepatic disorders and potential therapeutics modulating their activity.

Tumor and Stromal Cell Targeting with Nintedanib and Alpelisib Overcomes Intrinsic Bladder Cancer Resistance

Bladder cancer is a highly prevalent tumor, requiring the urgent development of novel therapies, especially for locally advanced and metastatic disease. Nintedanib is a potent antifibrotic angio-kinase inhibitor, which has shown clinical efficacy in combination with chemotherapy in patients with locally advanced muscle-invasive bladder cancer. Nintedanib inhibits fibroblast growth factor receptors (FGFRs), validated targets in patients with bladder cancer harboring FGFR3/2 genetic alterations. Here, we aimed at studying its mechanisms of action to understand therapy resistance, identify markers predictive of response, and improve the design of future clinical trials. We have used a panel of genetically well-characterized human bladder cancer cells to identify the molecular and transcriptomic changes induced upon treatment with nintedanib, in vitro and in vivo, at the tumor and stroma cell levels. We showed that bladder cancer cells display an intrinsic resistance to nintedanib treatment in vitro, independently of their FGFR3 status. However, nintedanib has higher antitumor activity on mouse xenografts. We have identified PI3K activation as a resistance mechanism against nintedanib in bladder cancer and evidenced that the combination of nintedanib with the PI3K inhibitor alpelisib has synergistic antitumor activity. Treatment with this combination is associated with cell-cycle inhibition at the tumoral and stromal levels and potent nontumor cell autonomous effects on α-smooth muscle actin-positive tumor infiltrating cells and tumor vasculature. The combination of nintedanib with PI3K inhibitors not only reversed bladder cancer resistance to nintedanib but also enhanced its antiangiogenic effects.

A review on emerging targeted therapies for the management of metastatic colorectal cancers

Colorectal cancers are among the most commonly found cancers over the world. In spite of the recent advancements in diagnosis and prognosis, the management of this metastatic condition remains a challenge. The utility of monoclonal antibodies in the healing of patients with colorectal cancer has opened a new chapter in the quest for newer therapies. The resistance to the standard treatment regimen made it mandatory to search for newer targets. Mutagenic alterations in the gene engaged in cellular differentiation and growth pathway have been the reason for resistance to treatment. The newer therapies target the various proteins and receptors involved in the signal transduction and down streaming pathways leading to cell proliferation. This review presents an insight into the newer targeted therapies for colorectal cancer involving tyrosine kinase blockers, epidermal growth factor receptors, vascular endothelial growth factor, immune checkpoint therapy, and BRAF inhibitors.

Anti-angiogenic agents for NSCLC following first-line immunotherapy: Rationale, recent updates, and future perspectives

The implementation of immune checkpoint inhibitors (ICIs), with or without chemotherapy, as first-line treatment for patients who do not have actionable mutations has proved to be a major paradigm shift in the management of advanced non-small cell lung cancer (NSCLC). However, the transition of ICIs, such as pembrolizumab and nivolumab, to a first-line setting has left an unmet need for effective second-line treatment options, which is an area of intense research. In 2020, we reviewed the biological and mechanistic rationale for anti-angiogenic agents in combination with, or following, immunotherapy with the aim of eliciting a so called 'angio-immunogenic' switch in the tumor microenvironment. Here, we review the latest clinical evidence of the benefits of incorporating anti-angiogenic agents into treatment regimens. While there is a paucity of prospective data, several recent observational studies indicate that the marketed anti-angiogenic drugs, nintedanib or ramucirumab, are effective in combination with docetaxel following immuno-chemotherapy. Addition of anti-angiogenics, like bevacizumab, have also demonstrated clinical benefit when combined with first-line immuno-chemotherapy regimens. Ongoing clinical trials are assessing these agents in combination with ICIs, with encouraging early results (e.g., ramucirumab plus pembrolizumab in LUNG-MAP S1800A). Also, several emerging anti-angiogenic agents combined with ICIs are currently being assessed in phase III trials following immunotherapy, including lenvatinib (LEAP-008), and sitravatinib (SAPPHIRE) It is hoped that these trials will help expand second-line treatment options in patients with NSCLC. Areas of focus in the future will include further molecular dissection of the mechanisms of resistance to immunotherapy and the various response-progression profiles to immunotherapy observed in the clinic and the monitoring of the dynamics of immunomodulation over the course of treatment. Improved understanding of these phenomena may help identify clinical biomarkers and inform the optimal use of anti-angiogenics in the treatment of individual patients.

Designing of kinase hinge binders: A medicinal chemistry perspective

Protein kinases are key regulators of cellular signaling and play a critical role in oncogenesis. Inhibitors of protein kinases are pursued by both industry and academia as a promising target for cancer therapy. Within the protein kinases, the ATP site has produced more than 40 FDA-approved drugs. The ATP site is broadly composed of a hinge region, gatekeeper residues, DFG-loop, ribose pocket, and other hydrophobic regions. The hinge region in the ATP site can be used for designing potent inhibitors. In this review, we discuss some representative studies that will highlight the interactions of heterocyclic compounds with hinge regions of different kinases like BRAF kinase, EGRF kinase, MAP kinase, and Mps1 kinase.

Salt-inducible kinase 2 regulates fibrosis during bleomycin-induced lung injury

Idiopathic pulmonary fibrosis is a progressive and normally fatal disease with limited treatment options. The tyrosine kinase inhibitor nintedanib has recently been approved for the treatment of idiopathic pulmonary fibrosis, and its effectiveness has been linked to its ability to inhibit a number of receptor tyrosine kinases including the platelet-derived growth factor, vascular endothelial growth factor, and fibroblast growth factor receptors. We show here that nintedanib also inhibits salt-inducible kinase 2 (SIK2), with a similar IC50 to its reported tyrosine kinase targets. Nintedanib also inhibited the related kinases SIK1 and SIK3, although with 12-fold and 72-fold higher IC50s, respectively. To investigate if the inhibition of SIK2 may contribute to the effectiveness of nintedanib in treating lung fibrosis, mice with kinase-inactive knockin mutations were tested using a model of bleomycin-induced lung fibrosis. We found that loss of SIK2 activity protects against bleomycin-induced fibrosis, as judged by collagen deposition and histological scoring. Loss of both SIK1 and SIK2 activity had a similar effect to loss of SIK2 activity. Total SIK3 knockout mice have a developmental phenotype making them unsuitable for analysis in this model; however, we determined that conditional knockout of SIK3 in the immune system did not affect bleomycin-induced lung fibrosis. Together, these results suggest that SIK2 is a potential drug target for the treatment of lung fibrosis.

Nintedanib plus docetaxel after progression on first-line immunochemotherapy in patients with lung adenocarcinoma: Cohort C of the non-interventional study, VARGADO

BACKGROUND

Immune checkpoint inhibitors (ICIs) with or without chemotherapy represent first-line standard of care for patients with advanced non-small cell lung cancer (NSCLC) without targetable driver mutations. The most appropriate second-line therapy after failing immunochemotherapy remains an open question. Nintedanib, an oral triple angiokinase inhibitor that targets the vascular endothelial growth factor receptor, fibroblast growth factor receptor, and, platelet-derived growth factor receptor, in combination with docetaxel, is approved for treatment of advanced NSCLC (adenocarcinoma histology) following progression on first-line chemotherapy.

METHODS

VARGADO (NCT02392455) is an ongoing, prospective, non-interventional study investigating the efficacy and safety of nintedanib plus docetaxel following first-line chemotherapy with or without ICIs in patients with locally advanced, metastatic, or locally recurrent NSCLC of adenocarcinoma histology. This analysis focuses on Cohort C, which enrolled patients who had received prior first line chemotherapy with ICIs. Patients received second-line docetaxel (75 mg/m²) by intravenous infusion on Day 1, plus oral nintedanib (200 mg twice daily) on Days 2-21 of each 21-day cycle during routine clinical care. The primary endpoint is overall survival (OS) rate 1 year after the start of treatment with nintedanib plus docetaxel. Secondary endpoints include progression-free survival (PFS), OS, and disease control rate (DCR). Safety was also assessed.

RESULTS

Among 137 patients treated, the median age was 63 years (range, 37-84); 57 patients (41.6%) were female, most patients had Eastern Cooperative Oncology Group performance status of 0 (28.5%) or 1 (43.1%); 118 (86.1%) had stage IV NSCLC and 27 (19.7%) had brain metastases. Most (n=120, 87.6%) patients had received pembrolizumab/pemetrexed/platinum-based chemotherapy as first-line treatment. In 80 patients with available response data, the DCR was 72.5% (complete response: 1.3%; partial response: 36.3%; stable disease: 35.0%). Median progression-free survival was 4.8 months (95% confidence interval: 3.7-6.6). OS data were immature. Grade ≥3 treatment-emergent adverse events (TEAEs), serious TEAEs, and TEAEs leading to treatment discontinuation were reported in 62 (45.3%), 50 (36.5%), and 40 patients (29.2%), respectively.

CONCLUSIONS

This analysis indicates that nintedanib plus docetaxel represents an effective second-line treatment option in patients with advanced adenocarcinoma NSCLC following progression on first-line immunochemotherapy. The safety profile was manageable with no unexpected signals.

Pleiotropic effects of DCLK1 in cancer and cancer stem cells

Doublecortin-like kinase 1 (DCLK1), a protein molecule, has been identified as a tumor stem cell marker in the cancer cells of gastrointestinal, pancreas, and human colon. DCLK1 expression in cancers, such as breast carcinoma, lung carcinoma, hepatic cell carcinoma, tuft cells, and human cholangiocarcinoma, has shown a way to target the DCLK1 gene and downregulate its expression. Several studies have discussed the inhibition of tumor cell proliferation along with neoplastic cell arrest when the DCLK1 gene, which is expressed in both cancer and normal cells, was targeted successfully. In addition, previous studies have shown that DCLK1 plays a vital role in various cancer metastases. The correlation of DCLK1 with numerous stem cell receptors, signaling pathways, and genes suggests its direct or an indirect role in promoting tumorigenesis. Moreover, the impact of DCLK1 was found to be related to the functioning of an oncogene. The downregulation of DCLK1 expression by using targeted strategies, such as embracing the use of siRNA, miRNA, CRISPR/Cas9 technology, nanomolecules, specific monoclonal antibodies, and silencing the pathways regulated by DCLK1, has shown promising results in both in vitro and in vivo studies on gastrointestinal (GI) cancers. In this review, we will discuss about the present understanding of DCLK1 and its role in the progression of GI cancer and metastasis.

Current Advances in Chitosan Nanoparticles Based Oral Drug Delivery for Colorectal Cancer Treatment

As per the WHO, colorectal cancer (CRC) caused around 935,173 deaths worldwide in 2020 in both sexes and at all ages. The available anticancer therapies including chemotherapy, radiotherapy and anticancer drugs are all associated with limited therapeutic efficacy, adverse effects and low chances. This has urged to emerge several novel therapeutic agents as potential therapies for CRC including synthetic and natural materials. Orally administrable and targeted drug delivery systems are attractive strategies for CRC therapy as they minimize the side effects, enhance the efficacy of anticancer drugs. Nevertheless, oral drug delivery till today faces several challenges like poor drug solubility, stability, and permeability. Various oral nano-based approaches and targeted drug delivery systems have been developed recently, as a result of the ability of nanoparticles to control the release of the encapsulant, drug targeting and reduce the number of dosages administered. The unique physicochemical properties of chitosan polymer assist to overcome oral drug delivery barriers and target the colon tumour cells. Chitosan-based nanocarriers offered additional improvements by enhancing the stability, targeting and bioavailability of several anti-colorectal cancer agents. Modified chitosan derivatives also facilitated CRC targeting through strengthening the protection of encapsulant against acidic and enzyme degradation of gastrointestinal track (GIT). This review aims to provide an overview of CRC pathology, therapy and the barriers against oral drug delivery. It also emphasizes the role of nanotechnology in oral drug targeted delivery system and the growing interest towards chitosan and its derivatives. The present review summarizes the relevant works to date that have studied the potential applications of chitosan-based nanocarrier towards CRC treatment.

Nintedanib modulates type III collagen turnover in viable precision-cut lung slices from bleomycin-treated rats and patients with pulmonary fibrosis

BACKGROUND

Aberrant extracellular matrix (ECM) deposition and remodelling is important in the disease pathogenesis of pulmonary fibrosis (PF). We characterised neoepitope biomarkers released by ECM turnover in lung tissue from bleomycin-treated rats and patients with PF and analysed the effects of two antifibrotic drugs: nintedanib and pirfenidone.

METHODS

Precision-cut lung slices (PCLS) were prepared from bleomycin-treated rats or patients with PF. PCLS were incubated with nintedanib or pirfenidone for 48 h, and levels of neoepitope biomarkers of type I, III and VI collagen formation or degradation (PRO-C1, PRO-C3, PRO-C6 and C3M) as well as fibronectin (FBN-C) were assessed in the culture supernatants.

RESULTS

In rat PCLS, incubation with nintedanib led to a reduction in C3M, reflecting type III collagen degradation. In patient PCLS, incubation with nintedanib reduced the levels of PRO-C3 and C3M, thus showing effects on both formation and degradation of type III collagen. Incubation with pirfenidone had a marginal effect on PRO-C3. There were no other notable effects of either nintedanib or pirfenidone on the other neoepitope biomarkers studied.

CONCLUSIONS

This study demonstrated that nintedanib modulates neoepitope biomarkers of type III collagen turnover and indicated that C3M is a promising translational neoepitope biomarker of PF in terms of therapy assessment.

Receptor Tyrosine Kinases Amplified in Diffuse-Type Gastric Carcinoma: Potential Targeted Therapies and Novel Downstream Effectors

Simple Summary

Diffuse-type gastric carcinoma (DGC) is an aggressive subtype of gastric carcinoma with an extremely poor prognosis due to frequent peritoneal metastasis and high probability of recurrence. Its pathogenesis is poorly understood, and consequently, no effective molecular targeted therapy is available. The importance of oncogenic receptor tyrosine kinase (RTK) signaling has been recently demonstrated in the malignant progression of DGC. In particular, RTK gene amplification appears to accelerate peritoneal metastasis. In this review, we provide an overview of RTK gene amplification in DGC and the potential of related targeted therapies.

Abstract

Gastric cancer (GC) is a major cause of cancer-related death worldwide. Patients with an aggressive subtype of GC, known as diffuse-type gastric carcinoma (DGC), have extremely poor prognoses. DGC is characterized by rapid infiltrative growth, massive desmoplastic stroma, frequent peritoneal metastasis, and high probability of recurrence. These clinical features and progression patterns of DGC substantially differ from those of other GC subtypes, suggesting the existence of specific oncogenic signals. The importance of gene amplification and the resulting aberrant activation of receptor tyrosine kinase (RTK) signaling in the malignant progression of DGC is becoming apparent. Here, we review the characteristics of RTK gene amplification in DGC and its importance in peritoneal metastasis. These insights may potentially lead to new targeted therapeutics.

Augmenting Experimental Gastric Cancer Activity of Irinotecan through Liposomal Formulation and Antiangiogenic Combination Therapy

Gastric adenocarcinoma (GAC) is the third most common cause of cancer-related deaths worldwide. Combination chemotherapy remains the standard treatment for advanced GAC. Liposomal irinotecan (nal-IRI) has improved pharmacokinetics (PK) and drug biodistribution compared with irinotecan (IRI, CPT-11). Angiogenesis plays a crucial role in the progression and metastasis of GAC. We evaluated the antitumor efficacy of nal-IRI in combination with novel antiangiogenic agents in GAC mouse models. Animal survival studies were performed in peritoneal dissemination xenografts. Tumor growth and PK studies were performed in subcutaneous xenografts. Compared with controls, extension in animal survival by nal-IRI and IRI was >156% and >94%, respectively. The addition of nintedanib or DC101 extended nal-IRI response by 13% and 15%, and IRI response by 37% and 31% (MKN-45 xenografts); nal-IRI response by 11% and 3%, and IRI response by 16% and 40% (KATO-III xenografts). Retardation of tumor growth was greater with nal-IRI (92%) than IRI (71%). Nintedanib and DC101 addition tend to augment nal-IRI or IRI response in this model. The addition of antiangiogenic agents enhanced tumor cell proliferation inhibition effects of nal-IRI or IRI. The tumor vasculature was decreased by nintedanib (65%) and DC101 (58%), while nal-IRI and IRI alone showed no effect. PK characterization in GAC xenografts demonstrated that compared with IRI, nal-IRI treatment groups had higher retention, circulation time, and tumor levels of CPT-11 and its active metabolite SN-38. These findings indicate that nal-IRI, alone and in combination with antiangiogenic agents, has the potential for improving clinical GAC therapy.

Discovery of 4-cyclopropyl-3-(2-((1-cyclopropyl-1H-pyrazol-4-yl) amino) quinazolin-6-yl)-N-(3-(trifluoromethyl) phenyl) benzamides as potent discoidin domain receptor inhibitors for the treatment of idiopathic pulmonary fibrosis

Idiopathic pulmonary fibrosis (IPF) is a chronic fatal lung disease with a median survival time of 3–5 years. Inaccurate diagnosis, limited clinical therapy and high mortality together indicate that the development of effective therapeutics for IPF is an urgent need. In recent years, it was reported that DDRs are potential targets in anti-fibrosis treatment. Based on previous work we carried out further structure modifications and led to a more selective inhibitor 47 by averting some fibrosis-unrelated kinases, such as RET, AXL and ALK. Extensive profiling of compound 47 has demonstrated that it has potent DDR1/2 inhibitory activities, low toxicity, good pharmacokinetic properties and reliable in vivo anti-fibrosis efficacy. Therefore, we confirmed that discoidin domain receptors are promising drug targets for IPF, and compound 47 would be a promising candidate for further drug development.

Vascular Endothelial Growth Factor Receptors [VEGFR] as Target in Breast Cancer Treatment: Current Status in Preclinical and Clinical Studies and Future Directions

Breast cancer [BC] is one of the most common cancers among women, one of the leading causes of a considerable number of cancer-related death globally. Among all procedures leading to the formation of breast tumors, angiogenesis has an important role in cancer progression and outcomes. Therefore, various anti-angiogenic strategies have developed so far to enhance treatment's efficacy in different types of BC. Vascular endothelial growth factors [VEGFs] and their receptors are regarded as the most well-known regulators of neovascularization. VEGF binding to vascular endothelial growth factor receptors [VEGFRs] provides cell proliferation and vascular tissue formation by the subsequent tyrosine kinase pathway. VEGF/VEGFR axis displays an attractive target for anti-angiogenesis and anti-cancer drug design. This review aims to describe the existing literature regarding VEGFR inhibitors, focusing on BC treatment reported in the last two decades.

The role of antifibrotics in the treatment of rheumatoid arthritis-associated interstitial lung disease

The major pulmonary complication of rheumatoid arthritis (RA) is interstitial lung disease (ILD), which causes significant morbidity and mortality and influences the natural course of disease. Recent advances in the management of arthritis have improved patient outcomes. However, exceptionally high medical needs still remain for effective therapies for the patients with ILD in RA. Better understanding of the shared and distinct pathophysiology of fibrotic diseases led to the development of novel antifibrotic agents such as nintedanib and pirfenidone. The further stratification analysis of the phase III INBUILD trial demonstrated beneficial effects of nintedanib in RA-ILD with a progressive phenotype by reducing the rate of decline in forced vital capacity (FVC) over 52 weeks by 60%. Pirfenidone is another antifibrotic agent currently under phase II clinical study (TRAIL1) aiming to evaluate its effects for RA-ILD. This review provides an overview of state-of-the-art pathogenesis and the current therapeutic options for RA-ILD, with a focus on antifibrotic strategies.

Targeted Self-Emulsifying Drug Delivery Systems to Restore Docetaxel Sensitivity in Resistant Tumors

The use of chemotherapeutic agents such as docetaxel (DTX) in anticancer therapy is often correlated to side effects and the occurrence of drug resistance, which substantially impair the efficacy of the drug. Here, we demonstrate that self-emulsifying drug delivery systems (SEDDS) coated with enoxaparin (Enox) are a promising strategy to deliver DTX in resistant tumors. DTX partition studies between the SEDDS pre-concentrate and the release medium (water) suggest that the drug is well retained within the SEDDS upon dilution in the release medium. All SEDDS formulations show droplets with a mean diameter between 110 and 145 nm following dilution in saline and negligible hemolytic activity; the droplet size remains unchanged upon sterilization. Enox-coated SEDDS containing DTX exhibit an enhanced inhibition of cell growth compared to the control on cells of different solid tumors characterized by high levels of FGFR, which is due to an increased DTX internalization mediated by Enox. Moreover, only Enox-coated SEDDS are able to restore the sensitivity to DTX in resistant cells expressing MRP1 and BCRP by inhibiting the activity of these two main efflux transporters for DTX. The efficacy and safety of these formulations is also confirmed in vivo in resistant non-small cell lung cancer xenografts.

Real-World Efficacy of Nintedanib Plus Docetaxel After Progression on Immune Checkpoint Inhibitors: Results From the Ongoing, Non-interventional VARGADO Study

AIMS

To evaluate the efficacy and safety of nintedanib plus docetaxel in patients with advanced adenocarcinoma non-small cell lung cancer (NSCLC) who progressed after chemotherapy and immune checkpoint inhibitor (ICI) therapy.

MATERIALS AND METHODS

VARGADO (NCT02392455) is an ongoing, prospective, non-interventional, real-world study of nintedanib plus docetaxel after first-line chemotherapy in the routine clinical treatment of patients with locally advanced, metastatic or locally recurrent adenocarcinoma NSCLC. Data were collected during routine visits. We report the results from cohort B (n = 80), who received third-line nintedanib plus docetaxel after first-line chemotherapy and second-line ICI therapy.

RESULTS

The median duration of follow-up was 12.4 months. Median progression-free survival from initiation of third-line nintedanib plus docetaxel was 6.4 months (95% confidence interval 4.8, 7.3); median overall survival was 12.1 months (95% confidence interval 9.4, 13.5). The 1-year overall survival rate after initiation of third-line nintedanib plus docetaxel treatment (primary end point) was 52% (95% confidence interval 38.0%, 64.4%). Among 64 patients with a documented response, the objective response rate was 50% (n = 32; one complete response and 31 partial responses) and the disease control rate was 86% (n = 55). There were no new safety signals or unexpected toxicities. Among all treated patients, 74% (n = 59) experienced drug-related adverse events, most commonly (nintedanib-related/docetaxel-related) diarrhoea (34%/24%), a decreased white blood cell count (11%/19%) and nausea (13%/16%).

CONCLUSIONS

Nintedanib plus docetaxel demonstrated a high response rate and disease stabilisation in the third-line setting after failure of prior chemotherapy and ICI treatment, with a manageable safety profile. These results suggest that nintedanib plus docetaxel represents an efficient treatment option after failure of prior ICIs. The ongoing VARGADO study provides valuable real-world data to inform clinical decision-making regarding treatment sequencing after chemotherapy and ICI failure in patients with adenocarcinoma NSCLC.

FGFR Pathway Inhibition in Gastric Cancer: The Golden Era of an Old Target?

Gastric cancer (GC) is the third leading cause of cancer-associated death worldwide. The majority of patients are diagnosed at an advanced/metastatic stage of disease due to a lack of specific symptoms and lack of screening programs, especially in Western countries. Thus, despite the improvement in GC therapeutic opportunities, the survival is disappointing, and the definition of the optimal treatment is still an unmet need. Novel diagnostic techniques were developed in clinical trials in order to characterize the genetic profile of GCs and new potential molecular pathways, such as the Fibroblast Growth Factor Receptor (FGFR) pathway, were identified in order to improve patient's survival by using target therapies. The aim of this review is to summarize the role and the impact of FGFR signaling in GC and to provide an overview regarding the potential effectiveness of anti-FGFR agents in GC treatment in the context of precision medicine.

Nintedanib plus Docetaxel after Immune Checkpoint Inhibitor Failure in Patients with Advanced Non-Small-Cell Lung Cancer: A Case Series

Advances in the treatment of non-small-cell lung cancers (NSCLCs) lacking an actionable driver mutation have included the approval of immunotherapies, such as monotherapy or in combination with chemotherapy. However, limited evidence exists to guide clinical decision-making after progression with immunotherapy. The vascular endothelial growth factor (VEGF) signaling pathway promotes tumor angiogenesis and the development of an immunosuppressive tumor microenvironment (TME). Anti-VEGF treatment is postulated to favor an immunosupportive TME through an "angio-immunogenic switch." Nintedanib, an anti-VEGF receptor treatment, is approved in the EU and other countries, in combination with docetaxel for the treatment of locally advanced, metastatic, or locally recurrent adenocarcinoma NSCLC after failure of first-line chemotherapy. We present a case series from 5 patients treated with nintedanib plus docetaxel, after chemotherapy and immunotherapy, during routine clinical practice in Austria and Hungary. Four patients were treated with nintedanib plus docetaxel as a second- or third-line treatment after chemotherapy and immunotherapy, and a fifth patient received immunotherapy before and after nintedanib plus docetaxel. Although these patients would typically have a poor prognosis, each achieved a partial response with nintedanib plus docetaxel, with response duration from 8 months to over 30 months. Adverse events were manageable. The fifth patient case shows that nintedanib does not preclude later-line immunotherapy or chemotherapy, supporting the angio-immunogenic switch hypothesis. Overall, the case studies indicate that nintedanib plus docetaxel is an effective and well tolerated treatment, after sequential or combined chemo-immunotherapy for advanced NSCLC, and is compatible with a rechallenge with immunotherapy.

Emerging Therapeutic Agents for Colorectal Cancer

There are promising new therapeutic agents for CRC patients, including novel small-molecule inhibitors and immune checkpoint blockers. We focused on emerging CRC’s therapeutic agents that have shown the potential for progress in clinical practice. This review provides an overview of tyrosine kinase inhibitors targeting VEGF and KIT, BRAF and MEK inhibitors, TLR9 agonist, STAT3 inhibitors, and immune checkpoint blockers (PD1/PDL-1 inhibitors), for which recent advances have been reported. These new agents have the potential to provide benefits to CRC patients with unmet medical needs.

Development, Optimization, and Pharmacokinetics Study of Bufalin/Nintedanib Co-loaded Modified Albumin Sub-microparticles Fabricated by Coaxial Electrostatic Spray Technology

Coaxial electrostatic spray technology has received extensive attention in fabricating micro/nanoparticles for drug delivery. However, there are few reports on applying this technology in preparing albumin nanoparticles. In this study, the bufalin (BF) and nintedanib (NDNB) co-loaded ursodeoxycholic acid and p-biguanides benzoic acid decorated albumin sub-microparticles (BN-DUB subMPs) were fabricated by coaxial electrostatic spray technology and optimized by central composite design. Five percent of albumin (contained 0.7% polyethylene oxide) solution was selected as the shell solution which ejected through outer axis with the flow rate of 0.07 mm/min, while the core solution which contained by BF and NDNB ethanol solution was ejected through inner axis with the flow rate of 0.05 mm/min. In vitro cell studies revealed that the modified albumin possessed good biocompatibility. What's more, the BN-DUB subMPs enhanced the inhibitory effect on the growth of LLC cells efficiently. The pharmacokinetics study showed that the t_1/2 and AUC_0-t of BN-DUB subMPs increased significantly compared with that of the drug solution, which indicated the improved in vivo stability of modified albumin nanoparticles. Thus, this study provided a novel and simple technical platform for the development of albumin-based drug carriers.

The beginning of the era of precision medicine for gastric cancer with fibroblast growth factor receptor 2 aberration

Despite recent advances in the systemic treatment of metastatic gastric cancer (GC), prognostic outcomes remain poor. Considerable research effort has been invested in characterizing the genomic landscape of GC and identifying potential therapeutic targets. FGFR2 is one of the most attractive targets because aberrations in this gene are frequently associated with GC, particularly the diffuse type in Lauren's classification, which confers an unfavorable prognosis. Based on the preclinical data, the FGFR2 signaling pathway plays a key role in the development and progression of GC, and several FGFR inhibitors have been clinically assessed. However, the lack of robust treatment efficacy has hampered precision medicine for patients with FGFR2-aberrant GC. Recently, the clinical benefits of the FGFR2-IIIb-selective monoclonal antibody bemarituzumab for FGFR2b-positive GC patients were shown in a randomized phase II FIGHT trial of bemarituzumab combined with the first-line chemotherapy. This trial demonstrates proof of concept, suggesting that FGFR2 is a relevant therapeutic target for patients with FGFR2b-positive GC and that bemarituzumab brings new hope for diffuse-type GC patients. In this review, we summarize the oncogenic roles of FGFR2 signaling and highlight the most recent advances in FGFR inhibitors based on the findings of pivotal clinical trials for patients with FGFR2-aberrant GC. Thus, the era of precision medicine for patients with FGFR2-aberrant GC will be opened.

A Drug-Drug Interaction Study to Investigate the Effect of Nintedanib on the Pharmacokinetics of Microgynon (Ethinylestradiol and Levonorgestrel) in Female Patients with Systemic Sclerosis-Associated Interstitial Lung Disease

Background and Objectives

Nintedanib is a tyrosine kinase inhibitor approved for the treatment of systemic sclerosis-associated interstitial lung disease (SSc-ILD), idiopathic pulmonary fibrosis, and other chronic fibrosing ILDs with a progressive phenotype. As nintedanib may cause foetal harm, patients taking nintedanib should avoid pregnancy. The objective of this study was to investigate the effect of nintedanib co-administration on the pharmacokinetics of Microgynon (ethinylestradiol and levonorgestrel) in female patients with SSc-ILD.

Methods

This was an open-label, two-period, fixed-sequence, drug–drug interaction study. Female patients with SSc and ≥ 10% extent of fibrotic ILD on a high-resolution computed tomography scan were eligible to participate. In Period 1, patients received one Microgynon tablet (ethinylestradiol 30 μg and levonorgestrel 150 μg) ≥ 3 days before the first administration of nintedanib in Period 2. In Period 2, patients received one Microgynon tablet following intake of nintedanib 150 mg twice daily for ≥ 10 consecutive days. The primary pharmacokinetic endpoints were the areas under the plasma concentration–time curve of ethinylestradiol and levonorgestrel over the time interval from 0 to the last quantifiable data point (AUC_0–tz) and the maximum measured concentrations of ethinylestradiol and levonorgestrel in plasma (C_max). The secondary pharmacokinetic endpoint was the area under the plasma concentration–time curve of ethinylestradiol and levonorgestrel over the time interval from 0 extrapolated to infinity (AUC_0–∞). The relative exposures of ethinylestradiol and levonorgestrel when administered alone and in combination with nintedanib were assessed using an ANOVA model.

Results

Seventeen patients were treated. Pharmacokinetic data from 15 patients were analysed. Plasma concentration–time profiles of ethinylestradiol and levonorgestrel were similar following administration of Microgynon before and after administration of nintedanib for ≥ 10 consecutive days. Adjusted geometric mean (gMean) ratios [90% confidence intervals (CIs)] for AUC_0‒tz (101.4% [92.8, 110.7]) and AUC_0‒∞ (101.2% [94.0, 109.1]) indicated that there was no difference in total ethinylestradiol exposure when Microgynon was administered before or after administration of nintedanib. The adjusted gMean ratio for C_max of ethinylestradiol (116.7% [90% CI 107.6, 126.5]) indicated an increase in peak exposure in the presence of nintedanib. Adjusted gMean ratios [90% CIs] for AUC_0-tz (96.4% [91.5, 101.6]) and C_max (100.9% [89.9, 113.2]) indicated that there was no difference in total or peak levonorgestrel exposure when Microgynon was administered before or after administration of nintedanib. The adjusted gMean ratio for AUC_0‒∞ of levonorgestrel indicated a decrease in total exposure in the presence of nintedanib (88.1% [90% CI 80.0, 97.0]).

Conclusion

Pharmacokinetic data indicate that there is no relevant effect of nintedanib on plasma exposure to ethinylestradiol and levonorgestrel in female patients with SSc-ILD.

Trial Registration

Clinicaltrials.gov NCT03675581.

Efficacy and safety of nintedanib in Japanese patients with progressive fibrosing interstitial lung diseases: Subgroup analysis of the randomised, double-blind, placebo-controlled, phase 3 INBUILD trial

BACKGROUND

The efficacy of nintedanib in progressive fibrosing interstitial lung diseases (ILDs) was demonstrated in the randomised, double-blind, placebo-controlled INBUILD trial. This subgroup analysis evaluated the efficacy and safety of nintedanib in the Japanese population.

METHODS

Patients with progressive fibrosing ILDs (evaluated by physicians within 24 months of screening) were randomised (1:1) to twice-daily 150-mg nintedanib or placebo; treatment continued until the last patient completed 52 weeks. The primary endpoint was the annual rate of decline in forced vital capacity (FVC) over 52 weeks. Time-to-first acute ILD exacerbation or death and time-to-death up until the last patient had completed the week 52 visit were evaluated. This subgroup analysis included 108 Japanese patients.

RESULTS

The adjusted annual rates of FVC decline (mL/year) over 52 weeks for Japanese patients were -148.31 (nintedanib) and -240.36 (placebo), adjusted difference: 92.05 (95% CI: -10.69-194.80) and for non-Japanese patients were -67.41 (nintedanib) and -177.65 (placebo), adjusted difference: 110.24 (95% CI: 64.97-155.52). No heterogeneity in treatment effect between Japanese and non-Japanese subgroups was observed (treatment-by-subgroup interaction, p = 0.75). The risks of "acute exacerbation or death" (hazard ratio, 0.30 [95% CI: 0.10-0.91]) and mortality (hazard ratio, 0.54 [95% CI: 0.14-2.11]) in Japanese patients were numerically lower for nintedanib than placebo. There were no new or unexpected safety findings.

CONCLUSIONS

In Japanese patients, nintedanib slowed ILD progression, evidenced by a reduction in the annual rate of decline in FVC vs placebo. The efficacy and safety of nintedanib in Japanese patients were consistent with the overall INBUILD population. CLINICALTRIALS.GOV: NCT02999178 (21-Dec-2016).

Epigenetic Regulation of Angiogenesis in Development and Tumors Progression: Potential Implications for Cancer Treatment

Angiogenesis is a multi-stage process of new blood vessel development from pre-existing vessels toward an angiogenic stimulus. The process is essential for tissue maintenance and homeostasis during embryonic development and adult life as well as tumor growth. Under normal conditions, angiogenesis is involved in physiological processes, such as wound healing, cyclic regeneration of the endometrium, placental development and repairing certain cardiac damage, in pathological conditions, it is frequently associated with cancer development and metastasis. The control mechanisms of angiogenesis in carcinogenesis are tightly regulated at the genetic and epigenetic level. While genetic alterations are the critical part of gene silencing in cancer cells, epigenetic dysregulation can lead to repression of tumor suppressor genes or oncogene activation, becoming an important event in early development and the late stages of tumor development, as well. The global alteration of the epigenetic spectrum, which includes DNA methylation, histone modification, chromatin remodeling, microRNAs, and other chromatin components, is considered one of the hallmarks of cancer, and the efforts are concentrated on the discovery of molecular epigenetic markers that identify cancerous precursor lesions or early stage cancer. This review aims to highlight recent findings on the genetic and epigenetic changes that can occur in physiological and pathological angiogenesis and analyze current knowledge on how deregulation of epigenetic modifiers contributes to tumorigenesis and tumor maintenance. Also, we will evaluate the clinical relevance of epigenetic markers of angiogenesis and the potential use of "epi-drugs" in modulating the responsiveness of cancer cells to anticancer therapy through chemotherapy, radiotherapy, immunotherapy and hormone therapy as anti-angiogenic strategies in cancer.

Targeting Rearranged during Transfection in Cancer: A Perspective on Small-Molecule Inhibitors and Their Clinical Development

Rearranged during transfection (RET) is a receptor tyrosine kinase essential for the normal development and maturation of a diverse range of tissues. Aberrant RET signaling in cancers, due to RET mutations, gene fusions, and overexpression, results in the activation of downstream pathways promoting survival, growth, and metastasis. Pharmacological manipulation of RET is effective in treating RET-driven cancers, and efforts toward developing RET-specific therapies have increased over the last 5 years. In 2020, RET-selective inhibitors pralsetinib and selpercatinib achieved clinical approval, which marked the first approvals for kinase inhibitors specifically developed to target the RET oncoprotein. This Perspective discusses current development and clinical applications for RET precision medicine by providing an overview of the incremental improvement of kinase inhibitors for use in RET-driven malignancies.

Silibinin Suppresses Tumor Cell-Intrinsic Resistance to Nintedanib and Enhances Its Clinical Activity in Lung Cancer

The anti-angiogenic agent nintedanib has been shown to prolong overall and progression-free survival in patients with advanced non-small-cell lung cancer (NSCLC) who progress after first-line platinum-based chemotherapy and second-line immunotherapy. Here, we explored the molecular basis and the clinical benefit of incorporating the STAT3 inhibitor silibinin-a flavonolignan extracted from milk thistle-into nintedanib-based schedules in advanced NSCLC. First, we assessed the nature of the tumoricidal interaction between nintedanib and silibinin and the underlying relevance of STAT3 activation in a panel of human NSCLC cell lines. NSCLC cells with poorer cytotoxic responses to nintedanib exhibited a persistent, nintedanib-unresponsive activated STAT3 state, and deactivation by co-treatment with silibinin promoted synergistic cytotoxicity. Second, we tested whether silibinin could impact the lysosomal sequestration of nintedanib, a lung cancer cell-intrinsic mechanism of nintedanib resistance. Silibinin partially, but significantly, reduced the massive lysosomal entrapment of nintedanib occurring in nintedanib-refractory NSCLC cells, augmenting the ability of nintedanib to reach its intracellular targets. Third, we conducted a retrospective, observational multicenter study to determine the efficacy of incorporating an oral nutraceutical product containing silibinin in patients with NSCLC receiving a nintedanib/docetaxel combination in second- and further-line settings (n = 59). Overall response rate, defined as the combined rates of complete and partial responses, was significantly higher in the study cohort receiving silibinin supplementation (55%) than in the control cohort (22%, p = 0.011). Silibinin therapy was associated with a significantly longer time to treatment failure in multivariate analysis (hazard ratio 0.43, p = 0.013), despite the lack of overall survival benefit (hazard ratio 0.63, p = 0.190). Molecular mechanisms dictating the cancer cell-intrinsic responsiveness to nintedanib, such as STAT3 activation and lysosomal trapping, are amenable to pharmacological intervention with silibinin. A prospective, powered clinical trial is warranted to confirm the clinical relevance of these findings in patients with advanced NSCLC.

Real-world efficacy of docetaxel plus nintedanib after chemo-immunotherapy failure in advanced pulmonary adenocarcinoma

Aim: This real-world analysis evaluated docetaxel plus nintedanib in patients with advanced pulmonary adenocarcinoma after chemotherapy and immune checkpoint inhibitor failure, for whom treatment options are limited. Methods: Data were sourced retrospectively from seven German centers. Results: Of 93 patients, overall response rate was 41.4% (disease control rate: 75.9%). Of 57 patients given third-line docetaxel plus nintedanib, overall response rate was 50.0% (disease control rate: 82.7%). Median overall survival following third-line docetaxel plus nintedanib was 8.4 months. Adverse events were consistent with the known safety profile of docetaxel plus nintedanib. Conclusion: To date, this was the largest retrospective, real-world analysis of docetaxel plus nintedanib after chemotherapy-immunotherapy failure, indicating that docetaxel plus nintedanib offers meaningful clinical benefits in this setting.

Angiokinase inhibition of VEGFR-2, PDGFR and FGFR and cell growth inhibition in lung cancer: Design, synthesis, biological evaluation and molecular docking of novel azaheterocyclic coumarin derivatives

The present work represents the design and synthesis of some azaheterocyclic coumarin derivatives which are evaluated as anti-lung cancer agents. Ten out of the twenty azaheterocyclic compounds showed superior activity than the standard drug staurosporine against non-small cell lung cancer (A549). Representing the four different azaheterocyclic series, compounds 4a, 5d, 6e, and 7d, which demonstrated IC_50s of 2.38, 2.39, 1.05 and 3.98 µM, respectively, each exhibiting the best cytotoxicity in its group, were selected for further assessment of their toxicity on normal lung cells (WI-38). Compound 4a was selected for further investigations because it remarkably revealed less cytotoxicity (IC₅₀ = 53.76 µM) than 7d (IC₅₀ = 19.95 µM) on (WI-38) compared to staurosporine (IC₅₀ = 24.41 µM). 4a was assessed for its ability to inhibit the angiokinases VEGFR-2, PDGFR, FGFR and the growth factor EGFR, remarkably it showed better VEGFR-2, PDGFR, FGFR inhibition than the reference drugs used and exhibited as well noticeable EGFR inhibition. Going further, 4a was capable of arresting the cell cycle at pre-G1 phase and S phase and inducing apoptosis. Moreover, the capability of the target 4a to interact with the key amino acids of VEGFR-2 binding site was detected by molecular docking. Finally, the in silico physicochemical properties of 4a were studied.

Fibroblast Growth Factor Receptor (FGFR) Signaling in GIST and Soft Tissue Sarcomas

Sarcomas are a heterogeneous group of rare malignancies originating from mesenchymal tissues with limited therapeutic options. Recently, alterations in components of the fibroblast growth factor receptor (FGFR) signaling pathway have been identified in a range of different sarcoma subtypes, most notably gastrointestinal stromal tumors, rhabdomyosarcomas, and liposarcomas. These alterations include genetic events such as translocations, mutations, and amplifications as well as transcriptional overexpression. Targeting FGFR has therefore been proposed as a novel potential therapeutic approach, also in light of the clinical activity shown by multi-target tyrosine kinase inhibitors in specific subtypes of sarcomas. Despite promising preclinical evidence, thus far, clinical trials have enrolled very few sarcoma patients and the efficacy of selective FGFR inhibitors appears relatively low. Here, we review the known alterations of the FGFR pathway in sarcoma patients as well as the preclinical and clinical evidence for the use of FGFR inhibitors in these diseases. Finally, we discuss the possible reasons behind the current clinical data and highlight the need for biomarker stratification to select patients more likely to benefit from FGFR targeted therapies.

Aberrant B Cell Receptor Signaling in Naïve B Cells from Patients with Idiopathic Pulmonary Fibrosis

Idiopathic pulmonary fibrosis (IPF) is a chronic and ultimately fatal disease in which an impaired healing response to recurrent micro-injuries is thought to lead to fibrosis. Recent findings hint at a role for B cells and autoimmunity in IPF pathogenesis. We previously reported that circulating B cells from a fraction of patients, compared with healthy controls, express increased levels of the signaling molecule Bruton’s tyrosine kinase (BTK). However, it remains unclear whether B cell receptor (BCR) signaling is altered in IPF. Here, we show that the response to BCR stimulation is enhanced in peripheral blood B cells from treatment-naïve IPF patients. We observed increased anti-immunoglobulin-induced phosphorylation of BTK and its substrate phospholipase Cγ2 (PLCγ2) in naïve but not in memory B cells of patients with IPF. In naïve B cells of IPF patients enhanced BCR signaling correlated with surface expression of transmembrane activator and calcium-modulator and cyclophilin ligand interactor (TACI) but not B cell activating factor receptor (BAFFR), both of which provide pro-survival signals. Interestingly, treatment of IPF patients with nintedanib, a tyrosine kinase inhibitor with anti-fibrotic and anti-inflammatory activity, induced substantial changes in BCR signaling. These findings support the involvement of B cells in IPF pathogenesis and suggest that targeting BCR signaling has potential value as a treatment option.