Exploring the multifaceted antitumor activity of axitinib in lung carcinoids.

Introduction: Lung carcinoids (LCs) are a type of neuroendocrine tumor (NET) that originate in the bronchopulmonary tract. LCs account for 20-25% of all NETs and approximately 1-2% of lung cancers. Given the highly vascularized nature of NETs and their tendency to overexpress vascular growth factor receptors (VEGFR), inhibiting angiogenesis appears as a potential therapeutic target in slowing down tumor growth and spread. This study evaluated the long-term antitumor activity and related mechanisms of axitinib (AXI), a VEGFR-targeting drug, in LC cell lines. Methods: Three LC cell lines (NCI-H727, UMC-11 and NCI-H835) were incubated with their respective EC50 AXI concentrations for 6 days. At the end of the incubation, FACS experiments and Western blot analyses were performed to examine changes in the cell cycle and the activation of apoptosis. Microscopy analyses were added to describe the mechanisms of senescence and mitotic catastrophe when present. Results: The primary effect of AXI on LC cell lines is to arrest tumor growth through an indirect DNA damage. Notably, AXI triggers this response in diverse manners among the cell lines, such as inducing senescence or mitotic catastrophe. The drug seems to lose its efficacy when the DNA damage is mitigated, as observed in NCI-H835 cells. Conclusion: The ability of AXI to affect cell viability and proliferation in LC tumor cells highlights its potential as a therapeutic agent. The role of DNA damage and the consequent activation of senescence seem to be a prerequisite for AXI to exert its function.

The protective effects of Axitinib on blood-brain barrier dysfunction and ischemia-reperfusion injury in acute ischemic stroke.

BACKGROUND AND PURPOSE: The pathophysiological features of acute ischemic stroke (AIS) often involve dysfunction of the blood-brain barrier (BBB), characterized by the degradation of tight junction proteins (Tjs) leading to increased permeability. This dysfunction can exacerbate cerebral injury and contribute to severe complications. The permeability of the BBB fluctuates during different stages of AIS and is influenced by various factors. Developing effective therapies to restore BBB function remains a significant challenge in AIS treatment. High levels of vascular endothelial growth factor (VEGF) in the early stages of AIS have been shown to worsen BBB breakdown and stroke progression. Our study aimed to investigate the protective effects of the VEGF receptor inhibitor Axitinib on BBB dysfunction and cerebral ischemia/reperfusion-induced injury. METHODS: BEnd3 cell exposed to oxygen-glucose deprivation (OGD) model was constructed to estimate pharmacological activity of Axitinib (400 ng/ml) on anti-apoptosis and pathological barrier function recovery. In vivo, rats were subjected to a 1 h transient middle cerebral artery occlusion and 23 h reperfusion (tMCAO/R) to investigate the permeability of BBB and cerebral tissue damage. Axitinib was administered through the tail vein at the beginning of reperfusion. BBB integrity was assessed by Evans blue leakage and the expression levels of Tjs claudin-5 and occludin. RESULTS: Our research revealed that co-incubation with Axitinib enhanced the cell viability of OGD-insulted bEnd3 cells, decreased LDH leakage rate, and suppressed the expression of apoptosis-related proteins cytochrome C and Bax. Axitinib also mitigated the damage to Tjs and facilitated the restoration of transepithelial electrical resistance in OGD-insulted bEnd.3 cells. In vivo, Axitinib administration reduced intracerebral Evans blue leakage and up-regulated the expression of Tjs in the penumbra brain tissue in tMCAO/R rats. Notably, 10 mg/kg Axitinib exerted a significant anti-ischemic effect by decreasing cerebral infarct volume and brain edema volume, improving neurological function, and reducing pro-inflammatory cytokines IL-6 and TNF-α in the brain. CONCLUSIONS: Our study highlights Axitinib as a potent protectant of blood-brain barrier function, capable of promoting pathological blood-brain barrier recovery through VEGF inhibition and increased expression of tight junction proteins in AIS. This suggests that VEGF antagonism within the first 24 h post-stroke could be a novel therapeutic approach to enhance blood-brain barrier function and mitigate ischemia-reperfusion injury.

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.

Neoadjuvant toripalimab combined with axitinib in patients with locally advanced clear cell renal cell carcinoma: a single-arm, phase II trial.

BACKGROUND: A combination of axitinib and immune checkpoint inhibitors (ICIs) demonstrated promising efficacy in the treatment of advanced renal cell carcinoma (RCC). This study aims to prospectively evaluate the safety, efficacy, and biomarkers of neoadjuvant toripalimab plus axitinib in non-metastatic clear cell RCC. METHODS: This is a single-institution, single-arm phase II clinical trial. Patients with non-metastatic biopsy-proven clear cell RCC (T2-T3N0-1M0) are enrolled. Patients will receive axitinib 5 mg twice daily combined with toripalimab 240 mg every 3 weeks (three cycles) for up to 12 weeks. Patients then will receive partial (PN) or radical nephrectomy (RN) after neoadjuvant therapy. The primary endpoint is objective response rate (ORR). Secondary endpoints include disease-free survival, safety, and perioperative complication rate. Predictive biomarkers are involved in exploratory analysis. RESULTS: A total of 20 patients were enrolled in the study, with 19 of them undergoing surgery. One patient declined surgery. The primary endpoint ORR was 45%. The posterior distribution of πORR had a mean of 0.44 (95% credible intervals: 0.24-0.64), meeting the predefined primary endpoint with an ORR of 32%. Tumor shrinkage was observed in 95% of patients prior to nephrectomy. Furthermore, four patients achieved a pathological complete response. Grade ≥3 adverse events occurred in 25% of patients, including hypertension, hyperglycemia, glutamic pyruvic transaminase/glutamic oxaloacetic transaminase (ALT/AST) increase, and proteinuria. Postoperatively, one grade 4a and eight grade 1-2 complications were noted. In comparison to patients with stable disease, responders exhibited significant differences in immune factors such as Arginase 1(ARG1), Melanoma antigen (MAGEs), Dendritic Cell (DC), TNF Superfamily Member 13 (TNFSF13), Apelin Receptor (APLNR), and C-C Motif Chemokine Ligand 3 Like 1 (CCL3-L1). The limitation of this trial was the small sample size. CONCLUSION: Neoadjuvant toripalimab combined with axitinib shows encouraging activity and acceptable toxicity in locally advanced clear cell RCC and warrants further study. TRIAL REGISTRATION NUMBER: clinicaltrials.gov, NCT04118855.

Anti-cancer drug axitinib: a unique tautomerism-induced dual-emissive probe for protein analysis.

A commercial anti-cancer drug, axitinib, exhibits very stable dual emissions for discrimination of human serum albumin.

Ex Vivo Evaluation of Antiangiogenic Drugs in Oral Cancer: Potential Implications for Targeting Vasculogenic Mimicry.

BACKGROUND/AIM: Oral squamous cell carcinoma (OSCC) is characterized by early metastasis, clinical resistance and poor prognosis. Recently, we showed that aggressive OSCC cells co-express endothelial cell markers and can form tube-like structures, known as vasculogenic mimicry (VM), a process associated with poor prognosis in head and neck cancers. Given the limited success of current antiangiogenic therapy in treating OSCC, this study sought to explore the efficiency of these drugs in targeting an ex vivo model of VM. MATERIALS AND METHODS: OSCC cell lines from the tongue and floor of the mouth in addition to human endothelial cells were used. The treatments comprised a set of clinically relevant antiangiogenic drugs: sorafenib, sunitinib, and axitinib, which were administered in different doses. Multiple ex vivo approaches including cell tubulogenesis, proliferation, apoptosis, and migration assays were used. RESULTS: Although these drugs inhibited the formation of endothelial cell capillaries, they showed clear differential effects on OSCC cell-derived VM and cell morphology. Sorafenib inhibited the tubulogenesis of aggressive OSCC cells compared with the limited effect of sunitinib and axitinib. Furthermore, our data consistently demonstrated a preferential efficacy of certain drugs over others. Sorafenib and sunitinib exhibited anti-cancer effects on tumor cell proliferation, apoptosis, and cell migration, compared with the limited effect of axitinib. CONCLUSION: The antiangiogenic drugs, except sorafenib, had limited effect on VM formation in vitro and exhibited varying anti-cancer effects on OSCC cells. These data support the notion that VM formation may in part explain the development of drug resistance in OSCC cells.

Neuropilin-1-Targeted Nanomedicine for Spatiotemporal Tumor Suppression through Photodynamic Vascular Damage and Antiangiogenesis.

Antiangiogenic therapy is an effective way to disrupt nutrient supply and starve tumors, but it is restricted by poor efficacy and negative feedback-induced tumor relapse. In this study, a neuropilin-1 (NRP-1)-targeted nanomedicine (designated as FPPT@Axi) is reported for spatiotemporal tumor suppression by combining photodynamic therapy (PDT) with antiangiogenesis. In brief, FPPT@Axi is prepared by utilizing an NRP-1-targeting chimeric peptide (Fmoc-K(PpIX)-PEG8-TKPRR) to encapsulate the antiangiogenic drug Axitinib (Axi). Importantly, the NRP-1-mediated targeting property enables FPPT@Axi to selectively concentrate at vascular endothelial and breast cancer cells, facilitating the production of reactive oxygen species (ROS) in situ for specific vascular disruption and enhanced cell apoptosis under light stimulation. Moreover, the codelivered Axi can further inhibit vascular endothelial growth factor receptor (VEGFR) to impair the negative feedback of PDT-induced tumor neovascularization. Consequently, FPPT@Axi spatiotemporally restrains the tumor growth through blocking angiogenesis, destroying tumor vessels, and inducing tumor apoptosis. Such an NRP-1-mediated targeting codelivery system sheds light on constructing an appealing candidate with translational potential by using clinically approved PDT and chemotherapy.

Virtual Screening, Docking, and Designing of New VEGF Inhibitors as Anti-cancer Agents.

BACKGROUND: VEGFR-2 tyrosine kinase inhibitors are receiving a lot of attention as prospective anticancer medications in the current drug discovery process. OBJECTIVE: This work aims to explore the PubChem library for novel VEGFR-2 kinase inhibitors. 1H-Indazole-containing drug AXITINIB, or AG-013736 (FDA approved), is chosen as a rational molecule for drug design. This scaffold proved its efficiency in treating cancer and other diseases as well. METHODS: The present study used the virtual screening of the database, protein preparation, grid creation, and molecular docking analyses. RESULTS: The protein was validated on different parameters like the Ramachandran plot, the ERRAT score, and the ProSA score. The Ramachandran plot revealed that 92.1% of the amino acid residues were located in the most favorable region; this was complemented by an ERRAT score (overall quality factor) of 96.24 percent and a ProSA (Z score) of -9.24 percent. The Lipinski rule of five was used as an additional filter for screening molecules. The docking results showed values of binding affinity between -14.08 and -12.34 kcal/mol. The molecule C1 showed the highest docking value of -14.08 Kcal/mol with the maximum number of strong H-bonds by -NH of pyridine to amino acid Cys104 (4.22Å), -NH of indazole to Glu108 (4.72), and Glu70 to bridge H of -NH. These interactions are similar to Axitinib docking interactions like Glu70, Cys104, and Glu102. The docking studies revealed that pi-alkyl bonds are formed with unsubstituted pyridine, whereas important H-bonds are observed with different substitutions around -NH. Based on potential findings, we designed new molecules, and molecular docking studies were performed on the same protein along with ADMET studies. The designed molecules (M1-M4) also showed comparable docking results similar to Axitinib, along with a synthetic accessibility score of less than 4.5. CONCLUSION: The docking method employed in this work opens up new possibilities for the design and synthesis of novel compounds that can act as VEGFR-2 tyrosine kinase inhibitors and treat cancer.

Knockdown of the VEGFB/VEGFR1 signaling suppresses pubertal mammary gland development of mice via the inhibition of PI3K/Akt pathway.

Vascular endothelial growth factor B (VEGFB) has been well demonstrated to play a crucial role in regulating vascular function by binding to the VEGF receptors (VEGFRs). However, the specific role of VEGFB and VEGFRs in pubertal mammary gland development remains unclear. In this study, we observed that blocking the VEGF receptors with Axitinib suppressed the pubertal mammary gland development. Meanwhile, the proliferation of mammary epithelial cells (HC11) was repressed by blocking the VEGF receptors with Axitinib. Additionally, knockdown of VEGFR1 rather than VEGFR2 and NRP1 elicited the inhibition of HC11 proliferation, suggesting the essential role of VEGFR1 during this process. Furthermore, Axitinib or VEGFR1 knockdown led to the inhibition of the PI3K/Akt pathway. However, the inhibition of HC11 proliferation induced by Axitinib and or VEGFR1 knockdown was eliminated by the Akt activator SC79, indicating the involvement of the PI3K/Akt pathway. Finally, the knockdown of VEGFB and VEGFR1 suppressed the pubertal development of mice mammary gland with the inhibition of the PI3K/Akt pathway. In summary, the results showed that knockdown of the VEGFB/VEGFR1 signaling suppresses pubertal mammary gland development of mice via the inhibition of the PI3K/Akt pathway, which provides a new target for the regulation of pubertal mammary gland development.

In vitro evaluation of the antitumor activity of axitinib in canine mammary gland tumor cell lines.

BACKGROUND: Axitinib, a potent and selective inhibitor of vascular endothelial growth factor (VEGF) receptor (VEGFR) tyrosine kinase 1,2 and 3, is used in chemotherapy because it inhibits tumor angiogenesis by blocking the VEGF/VEGFR pathway. In veterinary medicine, attempts have been made to apply tyrosine kinase inhibitors with anti-angiogenic effects to tumor patients, but there are no studies on axitinib in canine mammary gland tumors (MGTs). OBJECTIVES: This study aimed to confirm the antitumor activity of axitinib in canine mammary gland cell lines. METHODS: We treated canine MGT cell lines (CIPp and CIPm) with axitinib and conducted CCK, wound healing, apoptosis, and cell cycle assays. Additionally, we evaluated the expression levels of angiogenesis-associated factors, including VEGFs, PDGF-A, FGF-2, and TGF-ß1, using quantitative real-time polymerase chain reaction. Furthermore, we collected canine peripheral blood mononuclear cells (PBMCs), activated them with concanavalin A (ConA) and lipopolysaccharide (LPS), and then treated them with axitinib to investigate changes in viability. RESULTS: When axitinib was administered to CIPp and CIPm, cell viability significantly decreased at 24, 48, and 72 h (p < 0.001), and migration was markedly reduced (6 h, p < 0.05; 12 h, p < 0.005). The apoptosis rate significantly increased (p < 0.01), and the G2/M phase ratio showed a significant increase (p < 0.001). Additionally, there was no significant change in the viability of canine PBMCs treated with LPS and ConA. CONCLUSION: In this study, we confirmed the antitumor activity of axitinib against canine MGT cell lines. Accordingly, we suggest that axitinib can be applied as a new treatment for patients with canine MGTs.

HIF-1α promotes kidney organoid vascularization and applications in disease modeling.

BACKGROUND: Kidney organoids derived from human pluripotent stem cells (HiPSCs) hold huge applications for drug screening, disease modeling, and cell transplanting therapy. However, these applications are limited since kidney organoid cannot maintain complete morphology and function like human kidney. Kidney organoids are not well differentiated since the core of the organoid lacked oxygen, nutrition, and vasculature, which creates essential niches. Hypoxia-inducible factor-1 α (HIF-1α) serves as a critical regulator in vascularization and cell survival under hypoxia environment. Less is known about the role of HIF-1α in kidney organoids in this regard. This study tried to investigate the effect of HIF-1α in kidney organoid vascularization and related disease modeling. METHODS: For the vascularization study, kidney organoids were generated from human induced pluripotent stem cells. We overexpressed HIF-1α via plasmid transfection or treated DMOG (Dimethyloxallyl Glycine, an agent for HIF-1α stabilization and accumulation) in kidney progenitor cells to detect the endothelium. For the disease modeling study, we treated kidney organoid with cisplatin under hypoxia environment, with additional HIF-1α transfection. RESULT: HIF-1α overexpression elicited kidney organoid vascularization. The endothelial cells and angiotool analysis parameters were increased in HIF-1α plasmid-transfected and DMOG-treated organoids. These angiogenesis processes were partially blocked by VEGFR inhibitors, semaxanib or axitinib. Cisplatin-induced kidney injury (Cleaved caspase 3) was protected by HIF-1α through the upregulation of CD31 and SOD2. CONCLUSION: We demonstrated that HIF-1α elicited the process of kidney organoid vascularization and protected against cisplatin-induced kidney organoid injury in hypoxia environment.

[Mechanism of nuclear protein 1 in the resistance to axitinib in clear cell renal cell carcinoma].

OBJECTIVE: To explore the potential mechanism of resistance to axitinib in clear cell renal cell carcinoma (ccRCC), with a view to expanding the understanding of axitinib resistance, facilitating the design of more specific treatment options, and improving the treatment effectiveness and survival prognosis of patients. METHODS: By exploring the half maximum inhibitory concentration (IC50) of axitinib on ccRCC cell lines 786-O and Caki-1, cell lines resistant to axitinib were constructed by repeatedly stimulated with axitinib at this concentration for 30 cycles in vitro. Cell lines that were not treated by axitinib were sensitive cell lines. The phenotypic differences of cell proliferation and apoptosis levels between drug resistant and sensitive lines were tested. Genes that might be involved in the drug resistance process were screened from the differentially expressed genes that were co-upregulated in the two drug resistant lines by transcriptome sequencing. The expression level of the target gene in the drug resistant lines was verified by real-time quantitative polymerase chain reaction (RT-qPCR) and Western blot (WB). The expression differences of the target gene in ccRCC tumor tissues and adjacent tissues were analyzed in the Gene Expression Profiling Interactive Analysis (GEPIA) public database, and the impact of the target gene on the prognosis of ccRCC patients was analyzed in the Kaplan-Meier Plotter (K-M Plotter) database. After knocking down the target gene in the drug resistant lines using RNA interference by lentivirus vector, the phenotypic differences of the cell lines were tested again. WB was used to detect the levels of apoptosis-related proteins in the different treated cell lines to find molecular pathways that might lead to drug resistance. RESULTS: Cell lines 786-O-R and Caki-1-R resistant to axitinib were successfully constructed in vitro, and their IC50 were significantly higher than those of the sensitive cell lines (10.99 µmol/L, P < 0.01; 11.96 µmol/L, P < 0.01, respectively). Cell counting kit-8 (CCK-8) assay, colony formation, and 5-ethynyl-2 '-deoxyuridine (EdU) assay showed that compared with the sensitive lines, the proliferative ability of the resistant lines decreased, but apoptosis staining showed a significant decrease in the level of cell apoptosis of the resistant lines (P < 0.01). Although resistant to axitinib, the resistant lines had no obvious new replicated cells in the environment of 20 µmol/L axitinib. Nuclear protein 1 (NUPR1) gene was screened by transcriptome sequencing, and its RNA (P < 0.0001) and protein expression levels significantly increased in the resistant lines. Database analysis showed that NUPR1 was significantly overexpressed in ccRCC tumor tissue (P < 0.05); the ccRCC patients with higher expression ofNUPR1had a worse survival prognosis (P < 0.001). Apoptosis staining results showed that knockdown ofNUPR1inhibited the anti-apoptotic ability of the resistant lines to axitinib (786-O, P < 0.01; Caki-1, P < 0.05). WB results showed that knocking downNUPR1decreased the protein level of B-cell lymphoma-2 (BCL2), increased the protein level of BCL2-associated X protein (BAX), decreased the protein level of pro-caspase3, and increased the level of cleaved-caspase3 in the resistant lines after being treated with axitinib. CONCLUSION: ccRCC cell lines reduce apoptosis through theNUPR1 -BAX/ BCL2 -caspase3 pathway, which is involved in the process of resistance to axitinib.

Efficacy of avelumab plus axitinib versus sunitinib by numbers of IMDC risk factors and target tumor sites at baseline in advanced renal cell carcinoma: long-term follow-up results from JAVELIN Renal 101.

BACKGROUND: In the phase III JAVELIN Renal 101 trial, first-line avelumab + axitinib improved progression-free survival (PFS) and objective response rate versus sunitinib in patients with advanced renal cell carcinoma across all International Metastatic RCC Database Consortium (IMDC) risk groups (favorable, intermediate, and poor); analyses of overall survival (OS) remain immature. Here, we report post hoc analyses of efficacy from the third interim analysis (data cut-off, April 2020) by the numbers of IMDC risk factors and target tumor sites at baseline. METHODS: Efficacy endpoints assessed were PFS, objective response, and best overall response per investigator assessment (RECIST v1.1) and OS. Best percentage change and percentage change from baseline in target tumor size over time during the study were also assessed. RESULTS: In patients with 0, 1, 2, 3, or 4-6 IMDC risk factors, hazard ratios [HRs; 95% confidence interval (CIs)] for OS with avelumab + axitinib versus sunitinib were 0.660 (0.356-1.223), 0.745 (0.524-1.059), 0.973 (0.668-1.417), 0.718 (0.414-1.248), and 0.443 (0.237-0.829), and HRs (95% CIs) for PFS were 0.706 (0.490-1.016), 0.709 (0.540-0.933), 0.711 (0.527-0.960), 0.501 (0.293-0.854), and 0.395 (0.214-0.727), respectively. In patients with 1, 2, 3, or ≥4 target tumor sites, HRs (95% CIs) for OS with avelumab + axitinib versus sunitinib were 0.912 (0.640-1.299), 0.715 (0.507-1.006), 0.679 (0.442-1.044), and 0.747 (0.346-1.615), and HRs (95% CIs) for PFS were 0.706 (0.548-0.911), 0.552 (0.422-0.723), 0.856 (0.589-1.244), and 0.662 (0.329-1.332), respectively. Across all subgroups, analyses of objective response rate and complete response rate favored avelumab + axitinib versus sunitinib, and a greater proportion of patients treated with avelumab + axitinib had tumor shrinkage. CONCLUSIONS: In post hoc analyses, first-line treatment with avelumab + axitinib was generally associated with efficacy benefits versus treatment with sunitinib in patients with advanced renal cell carcinoma across subgroups defined by different numbers of IMDC risk factors or target tumor sites.

Combination BRAFV600E Inhibition with the Multitargeting Tyrosine Kinase Inhibitor Axitinib Shows Additive Anticancer Activity in BRAFV600E-Mutant Anaplastic Thyroid Cancer.

Background: Anaplastic thyroid cancer (ATC) is uniformly lethal. BRAFV600E mutation is present in 45% of patients with ATC. Targeted therapy with combined BRAF and MEK inhibition in BRAFV600E-mutant ATC can be effective, but acquired resistance is common because this combination targets the same pathway. Drug matrix screening, in BRAFV600E ATC cells, of highly active compounds in combination with BRAF inhibition showed multitargeting tyrosine kinase inhibitors (MTKIs) had the highest synergistic/additive activity. Thus, we hypothesized that the combination of BRAFV600E inhibition and an MTKI is more effective than a single drug or combined BRAF and MEK inhibition in BRAFV600E-mutant ATC. We evaluated the effect of BRAFV600E inhibitors in combination with the MTKI axitinib and its mechanism(s) of action. Methods: We evaluated the effects of BRAFV600E inhibitors and axitinib alone and in combination in in vitro and in vivo models of BRAFV600E-mutant and wild-type ATC. Results: The combination of axitinib and BRAFV600E inhibitors (dabrafenib and PLX4720) showed an additive effect on inhibiting cell proliferation based on the Chou-Talalay algorithm in BRAFV600E-mutant ATC cell lines. This combination also significantly inhibited cell invasion and migration (p < 0.001) compared with the control. Dabrafenib and PLX4720 arrested ATC cells in the G0/G1 phase. Axitinib arrested ATC cells in the G2/M phase by decreasing phosphorylation of aurora kinase B (Thr232) and histone H3 (Ser10) proteins and by upregulating the c-JUN signaling pathway. The combination of BRAF inhibition and axitinib significantly inhibited tumor growth and was associated with improved survival in an orthotopic ATC model. Conclusions: The novel combination of axitinib and BRAFV600E inhibition enhanced anticancer activity in in vitro and in vivo models of BRAFV600E-mutant ATC. This combination may have clinical utility in BRAFV600E-mutant ATC that is refractory to current standard therapy, namely combined BRAF and MEK inhibition.

PERK Inhibition by HC-5404 Sensitizes Renal Cell Carcinoma Tumor Models to Antiangiogenic Tyrosine Kinase Inhibitors.

PURPOSE: Tumors activate protein kinase R (PKR)-like endoplasmic reticulum kinase (PERK, also called EIF2AK3) in response to hypoxia and nutrient deprivation as a stress-mitigation strategy. Here, we tested the hypothesis that inhibiting PERK with HC-5404 enhances the antitumor efficacy of standard-of-care VEGF receptor tyrosine kinase inhibitors (VEGFR-TKI). EXPERIMENTAL DESIGN: HC-5404 was characterized as a potent and selective PERK inhibitor, with favorable in vivo properties. Multiple renal cell carcinoma (RCC) tumor models were then cotreated with both HC-5404 and VEGFR-TKI in vivo, measuring tumor volume across time and evaluating tumor response by protein analysis and IHC. RESULTS: VEGFR-TKI including axitinib, cabozantinib, lenvatinib, and sunitinib induce PERK activation in 786-O RCC xenografts. Cotreatment with HC-5404 inhibited PERK in tumors and significantly increased antitumor effects of VEGFR-TKI across multiple RCC models, resulting in tumor stasis or regression. Analysis of tumor sections revealed that HC-5404 enhanced the antiangiogenic effects of axitinib and lenvatinib by inhibiting both new vasculature and mature tumor blood vessels. Xenografts that progress on axitinib monotherapy remain sensitive to the combination treatment, resulting in ∼20% tumor regression in the combination group. When tested across a panel of 18 RCC patient-derived xenograft (PDX) models, the combination induced greater antitumor effects relative to monotherapies. In this single animal study, nine out of 18 models responded with ≥50% tumor regression from baseline in the combination group. CONCLUSIONS: By disrupting an adaptive stress response evoked by VEGFR-TKI, HC-5404 presents a clinical opportunity to improve the antitumor effects of well-established standard-of-care therapies in RCC.

Real-world clinical outcomes of patients with metastatic renal cell carcinoma receiving pembrolizumab + axitinib vs. ipilimumab + nivolumab.

BACKGROUND: Immune-Oncology (IO) therapies have changed first-line (1L) treatment paradigm for metastatic renal cell carcinoma (mRCC) in last few years with robust clinical trial data. We examined clinical outcomes among clear cell mRCC (mccRCC) patients who received pembrolizumab + axitinib (pembro-axi) or ipilimumab + nivolumab (ipi-nivo) in the US community oncology setting. METHODS: This retrospective cohort study utilized data from electronic health records and chart review within The US Oncology Network to identify adult patients with mccRCC initiating 1L pembro-axi or ipi-nivo from January 01, 2019 to December 31, 2020 and followed through March 31, 2021. Physician-recorded response (real-world overall response rate [rwORR] and real-world disease control rate [rwDCR]) was assessed descriptively. Real-world progression-free survival (rwPFS), real-world time to next treatment (rwTTNT) and time on treatment (rwToT) were estimated using Kaplan-Meier analysis. Association of 1L systemic treatment with time-to-event outcomes was examined using multivariable cox proportional hazards models. RESULTS: Study included 331 mccRCC patients (pembro-axi:44%, ipi-nivo:56%). Median age was 65 years, 75.5% were male, and 82.5% had intermediate/poor (I/P) IMDC risk score. RwORR and rwDCR were 71.0% and 80.0% for pembro-axi and 45.2% and 58.6% for ipi-nivo. In multivariable analysis, pembro-axi was associated with longer rwToT (aHR, 0.53 [95% CI, 0.40, 0.71]), rwTTNT (aHR, 0.60 [95% CI, 0.42, 0.87]), and rwPFS (aHR, 0.70 [95% CI, 0.49, 0.99]) compared to ipi-nivo (P < 0.01). CONCLUSIONS: Our study provides insight into newer mccRCC treatment tolerability and effectiveness in the real-world US community setting. Our real-world results were comparable to data from clinical trials, which is encouraging for mccRCC patients.

In vitro evaluation of Axitinib and Sorafenib treatment in glioblastoma cell viability and morphology.

The formation, proliferation, and evolution of glioblastoma (GB) are significantly influenced by pathological angiogenesis. This is supported by several growth factor receptors, such as the vascular endothelial growth factor receptor (VEGFR). In this experiment, we examined how the Food and Drug Administration (FDA) approved VEGFR blockers Sorafenib and Axitinib affect the viability of GB cells in vitro. Cells were cultivated in 96-well culture plates for the experiments, afterwards Sorafenib and Axitinib were administered at doses ranging from 0.3 µM to 80 µM. 2,5-Diphenyl-2H-tetrazolium bromide (MTT) assay was used to assess the impact of VEGFR inhibition on high-grade glioma (HGG) cell lines. To observe the morphological changes in cell shape, we used a 10× magnification microscopy. Our results showed that both Axitinib and Sorafenib retarded GB1B culture proliferation in a dose- and time-dependent manner in comparison to control cohorts that had not received any treatment. The half maximal inhibitory concentration (IC50) value for Axitinib was 3.5839 µM after three days of drug administration and 2.2133 µM after seven days of drug administration. The IC50 value for Sorafenib was 3.5152 µM after three days of drug administration and 1.6846 µM after seven days of drug administration. After the treatment with Axitinib or Sorafenib, very few cells became rounded and detached from the support, others remained adherent to the culture substrate, but acquired a larger, flatter shape. Our results indicate that VEGFR might serve as a key target in the treatment of GB. Although it is known that in vitro some drugs block the VEGFR more potently, clinical evidence is required to show whether this actually translates to better clinical outcomes.

Axitinib attenuates the progression of liver fibrosis by restoring mitochondrial function.

Liver fibrosis can progress to cirrhosis and hepatocellular carcinoma, which may eventually lead to liver failure and even death. No direct anti-fibrosis drugs are available at present. Axitinib is a new generation of potent multitarget tyrosine kinase receptor inhibitors, but its role in liver fibrosis remains unclear. In this study, a CCl4-induced hepatic fibrosis mouse model and a TGF-ß1-induced hepatic stellate cell model were used to explore the effect and mechanism of axitinib on hepatic fibrosis. Results confirmed that axitinib could alleviate the pathological damage of liver tissue induced by CCl4 and inhibit the production of glutamic-oxalacetic transaminase and glutamic-pyruvic transaminase. It also inhibited collagen and hydroxyproline deposition and the protein expression of Col-1 and α-SMA in CCl4-induced liver fibrosis. In addition, axitinib inhibited the expression of CTGF and α-SMA in TGF-ß1-induced hepatic stellate cells. Further studies showed that axitinib inhibited mitochondrial damage and reduced oxidative stress and NLRP3 maturation. The use of rotenone and antimycin A confirmed that axitinib could restore the activity of mitochondrial complexes I and III, thereby inhibiting the maturation of NLRP3. In summary, axitinib inhibits the activation of HSCs by enhancing the activity of mitochondrial complexes I and III, thereby alleviating the progression of liver fibrosis. This study reveals the strong potential of axitinib in the treatment of liver fibrosis.

Insulin receptor expression to predict resistance to axitinib and elucidation of the underlying molecular mechanism in metastatic renal cell carcinoma.

BACKGROUND: The study aimed to examine the significance of insulin receptor (INSR) expression in predicting resistance to axitinib in clear cell renal cell carcinoma (ccRCC). METHODS: Clinicopathological data were collected from 36 consecutive patients with metastatic RCC who received axitinib. Thirty-three primary tumours were obtained for immunohistochemistry. Patient-derived xenograft (PDX) models were created by transplanting primary tumours into immunodeficient mice, establishing axitinib-resistant PDX models. RCC cell lines were co-cultured with human renal glomerular endothelial cells (HGECs) treated with siRNA of INSR (HGEC-siINSR). Gene expression alteration was analysed using microarray. RESULTS: The patients with low INSR expression who received axitinib had a poorer outcome. Multivariate analysis showed that INSR expression was the independent predictor of progression-free survival. INSR expression decreased in axitinib-resistant PDX tumours. RCC cell lines showed upregulated interferon responses and highly increased interferon-ß levels by co-culturing with HGEC-siINSR. HGECs showed decreased INSR and increased interferon-ß after axitinib administration. RCC cell lines co-cultured with HGEC-siINSR showed high programmed death-ligand 1 (PD-L1) expression, which increased after interferon-ß administration. CONCLUSIONS: Decreased INSR in RCC could be a biomarker to predict axitinib resistance. Regarding the resistant mechanism, vascular endothelial cells with decreased INSR in RCC may secrete interferon-ß and induce PD-L1.

A phase II open-label trial of avelumab plus axitinib in previously treated non-small-cell lung cancer or treatment-naïve, cisplatin-ineligible urothelial cancer.

BACKGROUND: We hypothesized that avelumab plus axitinib could improve clinical outcomes in patients with advanced non-small-cell lung cancer (NSCLC) or urothelial carcinoma (UC). PATIENTS AND METHODS: We enrolled previously treated patients with advanced or metastatic NSCLC, or untreated, cisplatin-ineligible patients with advanced or metastatic UC. Patients received avelumab 800 mg every 2 weeks (Q2W) and axitinib 5 mg orally two times daily. The primary endpoint was objective response rate (ORR). Immunohistochemistry was used to assess programmed death-ligand 1 (PD-L1) expression (SP263 assay) and the presence of CD8+ T cells (clone C8/144B). Tumor mutational burden (TMB) was assessed by whole-exome sequencing. RESULTS: A total of 61 patients were enrolled and treated (NSCLC, n = 41; UC, n = 20); 5 remained on treatment at data cut-off (26 February 2021). The confirmed ORR was 31.7% in the NSCLC cohort and 10.0% in the UC cohort (all partial responses). Antitumor activity was observed irrespective of PD-L1 expression. In exploratory subgroups, ORRs were higher in patients with higher (≥median) CD8+ T cells in the tumor. ORRs were higher in patients with lower TMB (