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Familial hypertrophic cardiomyopathy (FHC) patients are advised to avoid strenuous exercise due to increased risk of arrhythmias. Mice expressing the human FHC-causing mutation R403Q in the myosin heavy chain gene (MYH6) recapitulate the human phenotype, including cytoskeletal disarray and increased arrhythmia susceptibility. Following in vivo administration of isoproterenol, mutant mice exhibited tachyarrhythmias, poor recovery and fatigue. Arrhythmias were attenuated with the β-blocker atenolol and protein kinase A inhibitor PKI. Mutant cardiac myocytes had significantly prolonged action potentials and triggered automaticity due to reduced repolarization reserve and connexin 43 expression. Isoproterenol shortened cycle length, and escalated electrical instability. Surprisingly isoproterenol did not increase CaV1.2 current. We found alterations in CaV1.2-β1 adrenergic receptor colocalization assessed using super-resolution nanoscopy, and increased CaV1.2 phosphorylation in mutant hearts. Our results reveal for the first time that altered ion channel expression, co-localization and β-adrenergic receptor signaling associated with myocyte disarray contribute to electrical instability in the R403Q mutant heart. [ABSTRACT FROM AUTHOR]

Introduction: Ribociclib and palbociclib are the inhibitors of cyclin-dependent kinase (CDK) 4/6 activity which have been used in the treatment of metastatic hormone receptor (HR)-positive, human epidermal growth factor receptor 2-negative breast cancer. QT interval prolongation has been the main reported adverse effect in Phase III trials of ribociclib and palbociclib therapy. In the present study, we aimed to evaluate electrocardiographic (ECG) changes in patients who received palbociclib and ribociclib therapy. Materials and Methods: Sixty women with metastatic HR-positive, human epidermal growth factor-2-negative breast cancer were included in the study. Baseline ECG and echocardiography examinations of these patients were done. Second control electrocardiogram was obtained on the 14th day of first-cycle therapy. PR interval, corrected QT (QTc) interval, QT dispersion (QTD), and QRS duration were calculated. Results: Heart rate, PR interval, QRS, QT, QTc, QTD, and corrected QTD duration did not differ before and after CDK 4/6 treatment. Two patients who received ribociclib and palbociclib treatment had basal QTc duration higher than 450 ms (458 ms and 465 ms, respectively). The 14th-day QTc intervals of these patients were found to be 318 ms and 406 ms, respectively. After CDK 4/6 treatment, only two patients had QTc interval of469 ms and 507 ms. The mean change of QTc interval before and during the 14th day of CDK 4/6 therapy was 7.38 ± 35.049 ms. When palbociclib and ribociclib treatments were analyzed separately, the baseline and 14th day of QTc interval were 415 ± 31.5 versus 428.11 ± 24.52 and 416.13 ± 26.05 versus 420.07 ± 31.32 ms, respectively. Conclusions: Ribociclib and palbociclib treatment was associated with a small statistically insignificant increase in QTc interval. Physicians should be aware of the side effect of these treatments. [ABSTRACT FROM AUTHOR]

Uterine leiomyosarcoma (uLMS) is an aggressive mesenchymal neoplasm associated with a poor prognosis. Systemic chemotherapy is the standard therapy for patients with uLMS. However, it is unclear which treatment regimen results in the most favorable clinical outcome. We performed a meta‐analysis and meta‐regression analysis to assess the efficiency of different treatments received by patients with advanced, metastatic, and relapsing uLMS by evaluating the objective response rate (ORR) and disease control rate (DCR) as primary endpoints. The frequentist random effects meta‐analysis model was used to compare the outcomes of different treatment regimens for advanced uLMS. A meta‐regression analysis was performed to estimate the association between the study‐specific hazard ratios and specific demographic variables. A meta‐analysis of 51 reports including 1664 patients was conducted. Among patients who received adjuvant chemotherapy (916 patients; 55%), gemcitabine and docetaxel were the most frequently used drugs. First‐line monotherapy with alkylating agents (pooled ORR = 0.48; 95% confidence interval [CI]: 0.44–0.52) and second‐line monotherapy with protein kinase inhibitors (pooled ORR = 0.45; 95% CI: 0.39–0.52) resulted in favorable prognoses. The combinations of anthracycline plus alkylating therapy (pooled DCR = 0.74; 95% CI: 0.67–0.79) and of gemcitabine plus docetaxel (pooled DCR = 0.70; 95% CI: 0.63–0.75) showed the greatest benefits when used as first‐line and second‐line chemotherapies, respectively. Subgroup meta‐analysis results revealed that dual‐regimen therapies comprising anthracycline plus alkylating therapy and gemcitabine plus docetaxel are practical therapeutic choices for International Federation of Gynecology and Obstetrics stages III–IVb with distant metastases when assessed by computed tomography (p = 0.001). Furthermore, neoadjuvant chemotherapy and local radiotherapy resulted in favorable outcomes for patients with earlier stages of distant relapsed uLMS (p < 0.001). Our findings provide a basis for designing new therapeutic strategies and can potentially guide clinical practice toward better prognoses for uLMS patients with advanced, metastatic, and relapsing disease. [ABSTRACT FROM AUTHOR]

Mastocytosis is amyeloid neoplasmresulting fromthe excessive proliferation and accumulation of neoplasticmast cells in one ormore organs. Systemicmastocytosis (SM) is a clonal hematopoietic stemcell neoplasm and a heterogeneous disease with several distinct subtypes. The majority of SM subtype in elderly patients belongs to advanced SM. Clinically, elderly patients with advanced SM carry a poor prognosis despite the use of cytoreductive therapy. Treatment with KIT tyrosine kinase inhibitors such as midostaurin and avapritinib has improved the outcome of advanced SMpatients. The safety and efficacy of KIT inhibitors were reviewed, and the future direction of clinical development was discussed. [ABSTRACT FROM AUTHOR]

Aim of the study: To assess the impact of primary radical treatment on the effectiveness and safety of systemic treatment with ribociclib in patients with advanced breast cancer. Material and methods: Retrospective data analysis of 180 patients with advanced breast cancer undergoing systemic treatment with ribociclib. The study included a retrospective analysis of data from 180 patients with advanced breast cancer undergoing systemic treatment with ribociclib. The study group included 106 (59%) patients who underwent radical treatment at earlier stages. The control group consisted of 74 patients (41%) diagnosed at an advanced stage. Results: The analysis showed that progression-free survival is longer in patients with primary advanced disease compared to patients with a history of radical treatment. The median PFS is 21.91 months for patients with a history of radical treatment, while for primary patients it is longer than the total observation time (p = 0.049). The median overall survival time did not reach statistical significance and was longer than the time of observation for both groups. In this study, it was observed that the most common adverse event was haematological complications. Neutropenia of any grade was observed in 82.78% of all patients, including G3/G4 neutropenia in 43.89% of patients. Anaemia of any degree was observed in 62.78% of patients, including G3/G4 anaemia in 1.67% of patients. Thrombocytopenia of any degree was observed in 62.78%. For the above complications, no statistically significant differences were observed between the study group and the control group. Conclusions: A higher benefit (expressed in PFS) from the use of ribociclib will be achieved by patients whose treatment was initiated at a locally advanced or metastatic stage compared to patients with a history of radical treatment of breast cancer. A history of primary radical treatment has no impact on either overall survival or the safety profile of ribociclib treatment. [ABSTRACT FROM AUTHOR]

Turmeronols (A and B), bisabolane-type sesquiterpenoids found in turmeric, reduce inflammation outside the brain in animals; however, their effects on neuroinflammation, a common pathology of various neurodegenerative diseases, are not understood. Inflammatory mediators produced by microglial cells play a key role in neuroinflammation, so this study evaluated the anti-inflammatory effects of turmeronols in BV-2 microglial cells stimulated with lipopolysaccharide (LPS). Pretreatment with turmeronol A or B significantly inhibited LPSinduced nitric oxide (NO) production; mRNA expression of inducible NO synthase; production of interleukin (IL)-1β, IL-6, and tumor necrosis factor α and upregulation of their mRNA expression; phosphorylation of nuclear factor-κB (NF-κB) p65 proteins and inhibitor of NF-κB kinase (IKK); and nuclear translocation of NF-κB. These results suggest that these turmeronols may prevent the production of inflammatory mediators by inhibiting the IKK/NF-κB signaling pathway in activated microglial cells and can potentially treat neuroinflammation associated with microglial activation. [ABSTRACT FROM AUTHOR]

Mast cells are leukocytes that mediate various aspects of immunity and drive allergic hypersensitivity pathologies. Mast cells differentiate from hematopoietic progenitor cells in a manner that is largely IL-3 dependent. However, molecular mechanisms, including the signaling pathways that control this process, have yet to be thoroughly investigated. Here, we examine the role of the ubiquitous and critical mitogen-activated protein kinase signaling pathway due to its position downstream of the IL-3 receptor. Hematopoietic progenitor cells were harvested from the bone marrow of C57BL/6 mice and differentiated to bone marrow–derived mast cells in the presence of IL-3 and mitogen-activated protein kinase inhibitors. Inhibition of the JNK node of the mitogen-activated protein kinase pathway induced the most comprehensive changes to the mature mast cell phenotype. Bone marrow–derived mast cells differentiated during impaired JNK signaling expressed impaired c-kit levels on the mast cell surface, first detected at week 3 of differentiation. Following 1 wk of inhibitor withdrawal and subsequent stimulation of IgE-sensitized FcεRI receptors with allergen (TNP-BSA) and c-kit receptors with stem cell factor, JNK-inhibited bone marrow–derived mast cells exhibited impediments in early-phase mediator release through degranulation (80% of control), as well as late-phase secretion of CCL1, CCL2, CCL3, TNF, and IL-6. Experiments with dual stimulation conditions (TNP-BSA + stem cell factor or TNP-BSA alone) showed that impediments in mediator secretion were found to be mechanistically linked to reduced c-kit surface levels. This study is the first to implicate JNK activity in IL-3–mediated mast cell differentiation and also identifies development as a critical and functionally determinative period. [ABSTRACT FROM AUTHOR]

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Why you should read this article: • To enhance your understanding of the benefits of a nurse-led clinic for patients receiving PARP inhibitors and other systemic anticancer treatments • To recognise that those responsible for leading and delivering a nurse-led service require the relevant training and competencies • To appreciate the importance of creating a business case when setting up a nurse-led clinic Nurse-led chemotherapy clinics are an essential part of UK oncology services. The approval of oral poly (adenosine diphosphate (ADP)-ribose) polymerase (PARP) inhibitors as maintenance treatment for people with platinum-responsive advanced ovarian cancer has provided patients with a new treatment option. However, due to their side effect profile, patients on these treatments require additional monitoring which can necessitate changes to the design of outpatient services. Nurse-led clinics designed specifically for patients receiving PARP inhibitors have been effective in addressing the additional monitoring requirements. This article provides a practical guide to developing a nurse-led clinic for patients receiving PARP inhibitors for advanced ovarian cancer and other systemic anticancer treatments. [ABSTRACT FROM AUTHOR]

Alpelisib is a specific oral PI3K inhibitor used combined with fulvestrant for the treatment of patients with HR+/HER2–/ PIK3CA- mutated metastatic breast cancer. Adverse drug reactions with alpelisib are common, including hyperglycemia and rash. Here we describe extraordinary and life-threatening reactions beyond skin rash in two patients with progressive PIK3CA- mutated metastatic cancer in whom alpelisib was initiated. Case-A (vaginal cancer): After 10 days on treatment, she developed dry eyes, generalized rash and itching. Alpelisib was interrupted and symptomatic treatment initiated. Because of an initial tumor response, a rechallenge was done. Ninety minutes after a reduced dose of alpelisib, she developed an anaphylactic reaction with angioedema, hypotension, and skin rash. Case-B (breast cancer): After 11 days on treatment, she developed skin rash and alpelisib was interrupted. At re-initiation, she felt tingles in her face and ears and some skin erythema. Given the mild rash, a second rechallenge with premedication was performed. Ninety minutes after a reduced dose of alpelisib, she developed a type-1 allergic reaction with angioedema, tingles, and skin rash. In both cases, a type-1 allergic reaction was diagnosed and symptomatic treatment was initiated, alpelisib was permanently discontinued and the patients fully recovered the next week(s). This report underlines the critical importance to consider type-I allergic reactions in the differential diagnosis in cases of rash associated with alpelisib. Even if a reaction develops after days on treatment, a type-I allergic reaction cannot be excluded. A rechallenge can be dangerous and should always be well contemplated or even avoided. [ABSTRACT FROM AUTHOR]

Asciminib is an allosteric high-affinity tyrosine kinase inhibitor (TKI) of the BCR-ABL1 protein kinase. This kinase is translated from the Philadelphia chromosome in chronic myeloid leukemia (CML). Marketing authorization for asciminib was granted on August 25, 2022 by the European Commission. The approved indication was for patients with Philadelphia chromosome-positive CML in the chronic phase which have previously been treated with at least 2 TKIs. Clinical efficacy and safety of asciminib were evaluated in the open-label, randomized, phase III ASCEMBL study. The primary endpoint of this trial was major molecular response (MMR) rate at 24 weeks. A significant difference in MRR rate was shown between the asciminib treated population and the bosutinib control group (25.5% vs. 13.2%, respectively, P  = .029). In the asciminib cohort, adverse reactions of at least grade 3 with an incidence ≥ 5% were thrombocytopenia, neutropenia, increased pancreatic enzymes, hypertension, and anemia. The aim of this article is to summarize the scientific review of the application which led to the positive opinion by the European Medicines Agency's Committee for Medicinal Products for Human Use. [ABSTRACT FROM AUTHOR]

Background This trial evaluated the safety and efficacy of ipatasertib in combination with carboplatin, carboplatin/paclitaxel, or capecitabine/atezolizumab in patients with metastatic triple–negative breast cancer (mTNBC). Methods Eligibility criteria were mTNBC, RECIST 1.1 measurable disease, no prior use of platinum for metastatic disease (Arms A and B), and no prior exposure to immune checkpoint inhibitor (Arm C). Primary endpoints were safety and RP2D. Secondary endpoints were progression–free survival (PFS), response rate, and overall survival. Results RP2D for Arm A (n = 10) was ipatasertib 300 mg daily, carboplatin AUC2, and paclitaxel 80 mg m−2 days 1, 8, and 15 every 28 days. RP2D for Arm B (n = 12) was ipatasertib 400 mg daily and carboplatin AUC2 days 1, 8, and 15 every 28 days. RP2D for Arm C (n = 6) was likely ipatasertib 300 mg 21 days on 7 days off, capecitabine 750 mg m−2, twice a day, 7 days on 7 days off, and atezolizumab 840 mg days 1 and 15 every 28 days. The most common (≥10%) grade 3-4 AEs at RP2D for Arm A (N = 7 at RP2D) were neutropenia (29%), diarrhea (14%), oral mucositis (14%), and neuropathy (14%); Arm B had diarrhea (17%) and lymphopenia (25%); and Arm C had anemia, fatigue, cognitive disturbance, and maculopapular rash (17% each). Overall responses at RP2D were 29% Arm A, 25% Arm B, and 33% Arm C. PFS was 4.8, 3.9, and 8.2 months for patients on Arms A, B, and C, respectively. Conclusions Continuous dosing of ipatasertib with chemotherapy was safe and well-tolerated. Further study is warranted in understanding the role of AKT inhibition in treatment of TNBCs. Trial registration NCT03853707. [ABSTRACT FROM AUTHOR]

Background Hyperglycemia is recognized as a common adverse event for patients receiving alpelisib but has been little studied outside of clinical trials. We report the frequency of alpelisib-associated hyperglycemia in a real-world setting and evaluate proposed risk factors. Patients and Methods We retrospectively identified patients with PIK3CA-mutated, hormone receptor-positive, metastatic breast cancer who initiated treatment with alpelisib plus fulvestrant between August 2019 and December 2021. Ordinal logistic regression evaluated 5 characteristics (diabetes, prediabetes, body mass index [BMI], age, and Asian ancestry) as independent risk factors for ALP-associated hyperglycemia grades 2-4. Risk of error from multiple hypothesis testing was controlled using the false discovery rate method. Results The study included n = 92 subjects, all but 1 female, mean age 59.9 (+11.9) years with 50% non-Hispanic White, 15% Hispanic/Latino, 13% Asian, 9% African/Black, and 13% other/unknown. In total 34% of patients had diabetes, 10% had pre-diabetes, and 56% had normoglycemia. Thirty-six percent were obese, 32% were overweight, 25% were normal weight, and 7% were lean. Frequency of grades 1-4 hyperglycemia in current subjects (64.1%) was similar to hyperglycemia reported in the SOLAR-1 trial (63.7%). Our subjects' risk of grades 2-4 hyperglycemia was independently increased by pre-existing diabetes (Odds ratio 3.75, 95% CI, 1.40-10.01), pre-diabetes (6.22, 1.12-34.47), Asian ancestry (7.10, 1.75-28.84), and each unit of BMI above 20 (1.17, 1.07-1.28). Conclusion While receiving alpelisib, patients of Asian ancestry, as well as patients with pre-existing hyperglycemia and/or BMI above 20, should be closely monitored for hyperglycemia. The mechanism underlying the current association of alpelisib-associated hyperglycemia with Asian ancestry is independent of BMI and merits further study. The high incidence of hyperglycemia resulted in a change in practice to include consultation with a diabetes nurse educator or endocrinologist at the start of alpelisib. [ABSTRACT FROM AUTHOR]

Salt-inducible kinase 2 (SIK2) is highly expressed in white adipocytes, but downregulated in individuals with obesity and insulin resistance. These conditions are often associated with a low-grade inflammation in adipose tissue. We and others have previously shown that SIK2 is downregulated by tumor necrosis factor α (TNFα), however, involvement of other pro-inflammatory cytokines, or the mechanisms underlying TNFα-induced SIK2 downregulation, remain to be elucidated. In this study we have shown that TNFα downregulates SIK2 protein expression not only in 3T3L1- but also in human in vitro differentiated adipocytes. Furthermore, monocyte chemoattractant protein-1 and interleukin (IL)-1β, but not IL-6, might also contribute to SIK2 downregulation during inflammation. We observed that TNFα-induced SIK2 downregulation occurred also in the presence of pharmacological inhibitors against several kinases involved in inflammation, namely c-Jun N-terminal kinase, mitogen activated protein kinase kinase 1, p38 mitogen activated protein kinase or inhibitor of nuclear factor kappa-B kinase (IKK). However, IKK may be involved in SIK2 regulation as we detected an increase of SIK2 when inhibiting IKK in the absence of TNFα. Increased knowledge about inflammation-induced downregulation of SIK2 could ultimately be used to develop strategies for the reinstalment of SIK2 expression in insulin resistance. [ABSTRACT FROM AUTHOR]

The nerve trunk healing process of a transected peripheral nerve trunk is composed of angiogenesis, nerve fiber regeneration, and scarring. Nerve trunk healing and neuroma formation probably share identical molecular mediators and similar regulations. At the nerve transection site, angiogenesis is sufficient and necessary for nerve fiber regeneration. Angiogenesis and nerve fiber regeneration reveal a positive correlation in the early time. Scarring and nerve fiber regeneration show a negative correlation in the late phase. We hypothesize that anti-angiogenesis suppresses neuromas. Subsequently, we provide potential protocols to test our hypothesis. Finally, we recommend employing anti-angiogenic small-molecule protein kinase inhibitors to investigate nerve transection injuries. [ABSTRACT FROM AUTHOR]

Backgrounds: PD-1 inhibitors and TKIs have been used to treat advanced osteosarcoma, but there is still a lack of intuitive data for the comparison of their efficacy. We conducted a meta-analysis to evaluate their therapeutic benefits. Methods: A systematic methodological search of five primary electronic databases was performed. Studies with a randomized design of any type about PD-1 inhibitors or TKIs for the treatment of advanced osteosarcoma were included. The primary outcomes mainly included CBR, PFS, OS and ORR, The CR, PR, SD and AEs were the secondary outcomes. The survival period (months) of patients was taken as the main analysis data. Random-effects models were used for meta-analysis. Results: Eight immunocheckpoint inhibitors in 327 patients from 10 clinical trials were finally evaluated. For OS, TKIs [11.67 months (95% CI, 9.32-14.01)] show more obvious advantages than PD-1 inhibitors [6.37 months (95% CI, 3.96-8.78)]. For PFS, TKIs [4.79 months (95% CI, 3.33-6.24)] are longer than PD-1 inhibitors [1.46 months (95% CI, 1.23-1.69)]. Although there was no fatal event, attention should still be paid, especially during the combined application of PD-1 inhibitors with TKIs since their obvious AEs. Conclusions: The findings of this study suggest that patients with advanced osteosarcoma, TKIs may be more beneficial than PD-1 inhibitors. TKIs combined with PD-1 inhibitors has a bright future in the treatment of advanced osteosarcoma, but we should always pay attention to the strong side effects. [ABSTRACT FROM AUTHOR]

Accumulation of 7-ketocholesterol (7KC) occurs in age-related macular degeneration (AMD) and was found previously to promote fibrosis, an untreatable cause of vision loss, partly through induction of endothelial-mesenchymal transition. To address the hypothesis that 7KC causes mesenchymal transition of retinal pigment epithelial cells (RPE), we exposed human primary RPE (hRPE) to 7KC or a control. 7KC-treated hRPE did not manifest increased mesenchymal markers, but instead maintained RPE-specific proteins and exhibited signs of senescence with increased serine phosphorylation of histone H3, serine/threonine phosphorylation of mammalian target of rapamycin (p-mTOR), p16 and p21, β-galactosidase labeling, and reduced LaminB1, suggesting senescence. The cells also developed senescence-associated secretory phenotype (SASP) determined by increased IL-1β, IL-6, and VEGF through mTOR-mediated NF-κB signaling, and reduced barrier integrity that was restored by the mTOR inhibitor, rapamycin. 7KC-induced p21, VEGF, and IL-1β were inhibited by an inhibitor of protein kinase C. The kinase regulates IQGAP1 serine phosphorylation. Furthermore, after 7KC injection and laser-induced injury, mice with an IQGAP1 serine 1441-point mutation had significantly reduced fibrosis compared to littermate control mice. Our results provide evidence that age-related accumulation of 7KC in drusen mediates senescence and SASP in RPE, and IQGAP1 serine phosphorylation is important in causing fibrosis in AMD. [ABSTRACT FROM AUTHOR]

Cushing’s syndrome is an endocrine disorder caused by excess production of the stress hormone cortisol. Precision medicine strategies have identified single allele mutations within the PRKACA gene that drive adrenal Cushing’s syndrome. These mutations promote perturbations in the catalytic core of protein kinase A (PKAc) that impair autoinhibition by regulatory subunits and compartmentalization via recruitment into AKAP signaling islands. PKAcL205R is found in ∼45% of patients, whereas PKAcE31V, PKAcW196R, and L198insW and C199insV insertion mutants are less prevalent. Mass spectrometry, cellular, and biochemical data indicate that Cushing’s PKAc variants fall into two categories: those that interact with the heat-stable protein kinase inhibitor PKI, and those that do not. In vitro activity measurements show that wild-type PKAc and W196R activities are strongly inhibited by PKI (IC50 < 1 nM). In contrast, PKAcL205R activity is not blocked by the inhibitor. Immunofluorescent analyses show that the PKI-binding variants wild-type PKAc, E31V, and W196R are excluded from the nucleus and protected against proteolytic processing. Thermal stability measurements reveal that upon co-incubation with PKI and metal-bound nucleotide, the W196R variant tolerates melting temperatures 10°C higher than PKAcL205. Structural modeling maps PKI-interfering mutations to a ∼20 Å diameter area at the active site of the catalytic domain that interfaces with the pseudosubstrate of PKI. Thus, Cushing’s kinases are individually controlled, compartmentalized, and processed through their differential association with PKI. [ABSTRACT FROM AUTHOR]

Thymic carcinoma is a highly malignant tumor and treatment options are limited. Lenvatinib, a novel multitargeted kinase inhibitor, has recently been approved for the treatment of unresectable thymic carcinoma. There are no reports of complete surgical resection after the administration of first‐line lenvatinib in advanced thymic carcinoma. A 50‐year‐old man visited our hospital because a computed tomography (CT) scan of the chest showed a large thymic squamous cell carcinoma. We suspected malignant pericardial effusion, invasion of the left upper lobe of the lung, and left mediastinal lymph node metastases. The patient was diagnosed with WHO classification stage IVb disease. Lenvatinib therapy was started at 24 mg/day as first‐line therapy. Gradual dose reduction to 16 mg/day was required because of hypertension, diarrhea, and palmar‐plantar erythrodysesthesia syndrome as side effects. Chest CT findings after 6 months of lenvatinib therapy showed reduction of the main tumor, disappearance of the mediastinal lymph node metastases, and pericardial effusion. Complete salvage resection was successfully performed a month after discontinuation of lenvatinib. The patient has been disease‐free for 1 year without adjuvant therapy. Lenvatinib therapy is one of the promising therapeutic options for thymic carcinoma and may make salvage surgery increasingly useful for advanced thymic carcinoma. [ABSTRACT FROM AUTHOR]

Introduction: PARP (Poly ADP Ribose Polymerase) inhibitors are an effective maintenance therapy for various entities, such as BRCA (breast cancer gene) mutated or HRD (homologous recombination deficiency) positive primary platin-sensitive advanced ovarian cancer after platin induction therapy and in relapse after responding to carboplatin reinduction. Other entities are metastatic BRCA mutated pancreas, prostate and Her2-negative breast cancer. Therefore, patients with allergic reactions to PARP inhibitors should undergo a desensitization procedure to be able to receive this efficient therapy. Case report: We conducted a two-day desensitization on a 45-year-s old patient with advanced ovarian cancer who displayed symptoms of an allergic reaction to Olaparib. Management and outcome: Using an Olaparib tablet suspension, we orally administered increasing Olaparib doses, starting with 12.5 mg and reaching a cumulative dose of 387.5 mg on the first day and starting with 100 mg and reaching a cumulative dose of 600 mg on the second day, without concomitant antiallergic medication. Except for mild erythema on day one receding within the hour, no further allergic reactions appeared during desensitization. The patient has since received 300 mg of Olaparib twice a day without further complications or interruptions. Conclusion: Desensitization in a two-day suspension protocol is a safe method that ensures effective maintenance therapy for patients with allergic reactions to PARP inhibitors. [ABSTRACT FROM AUTHOR]

Introduction: Cyclin-dependent kinase 4 and 6 inhibitors, ribociclib and palbociclib, are associated with reports of transaminitis and adverse cardiac events. Case report: The patient is a previously healthy 32-year-old female diagnosed with estrogen receptor-positive, progesterone receptor-positive, and human epidermal growth factor 2 negative metastatic breast cancer. From July to September 2021, the patient was initiated on ribociclib followed by palbociclib for metastatic breast cancer. She subsequently experienced two episodes of transaminitis and was diagnosed with cardiomyopathy. Management and outcome: The patient experienced transaminitis 2 weeks after the initiation of ribociclib resulting in discontinuation. When rechallenged with palbociclib, the patient experienced transaminitis within 1 week of initiation, which resulted in discontinuation. Approximately 1 month after palbociclib discontinuation, the patient was diagnosed with congestive heart failure with a left ventricular ejection fraction of 24%. Discussion: To our knowledge, there are few case studies investigating cyclin-dependent kinase 4 and 6 inhibitor rechallenge following transaminitis. Prior literature suggests that transaminitis with cyclin-dependent kinase 4 and 6 inhibitors is not a class effect, but this case report suggests otherwise. This report presents a rare case of cardiomyopathy and transaminitis following the administration of cyclin-dependent kinase 4 and 6 inhibitors, ribociclib and palbociclib. [ABSTRACT FROM AUTHOR]

Patients with metastatic renal cell carcinoma treated with tyrosine kinase inhibitors at a single academic medical center were retrospectively reviewed. These 139 real-world patients had high rates of dose reduction (52%) but low rates of drug discontinuation (11%), with lower relative dose intensity than reported in clinical trials. Background: Tyrosine kinase inhibitors (TKIs) that target the vascular endothelial growth factor receptor (VEGFR) are oral therapies used to treat metastatic renal cell carcinoma (mRCC). VEGFR TKI treatment is often complicated by dose-limiting adverse events (AE). We sought to describe dose intensity and clinical outcomes in a real-world cohort of patients treated with VEGFR TKIs to better characterize dosing patterns and toxicity management compared with previously reported clinical trials. Materials and Methods: We conducted a retrospective chart review of sequential patients with mRCC treated with VEGFR TKIs at 1 academic medical center from 2014 to 2021. Results: 139 patients (75% male, 75% white, median age 63 years) were treated with 185 VEGFR TKIs in our real-world cohort. Per International Metastatic RCC Database Consortium cr iter ia, 24% had good r isk, 54% intermediate risk, and 22% poor risk mRCC. With their first VEGFR TKI, median relative dose intensity (RDI) was 79%. 52% of patients required a dose reduction, 11% discontinued treatment due to AEs, 15% visited the ED, and 13% were hospitalized for treatment-related adverse events. Cabozantinib had the highest rate of dose reductions (72%) but a low rate of discontinuation (7%). Real-world patients consistently had lower RDI than reported clinical trials with more frequent dose reductions, fewer drug discontinuations, shorter progression-free survival, and shorter overall survival. Conclusion: Real-world patients were less able to tolerate VEGFR TKIs compared to patients treated on clinical trials. Low real-world RDI, high dose reductions, and low overall discontinuation rates can inform patient counseling prior to treatment initiation and during therapy. [ABSTRACT FROM AUTHOR]

Simple Summary: Cutaneous melanoma is one of the deadliest forms of skin cancer. While advancements in systemic targeted therapies and immunotherapies have greatly improved melanoma survival in recent years, tumor resistance can limit the efficacy of these therapies. Targeting redox homeostasis in melanoma progression is a promising therapeutic approach, especially in cases of melanoma drug resistance. The role of oxidative stress in melanoma is paradoxical in that it promotes tumor initiation but prevents vertical growth and metastasis. As the disease progresses, melanoma employs adaptive mechanisms to decrease oxidative stress in the tumor environment. Thus, agents with antioxidant properties may have the greatest utility in chemoprevention whereas those with pro-oxidant properties may be better suited for treatment. The purpose of this review is to provide an overview of oxidative stress in melanoma, and how the antioxidant system may be manipulated in a therapeutic context for improved efficacy and survival. Cutaneous melanoma ranks as the fifth most common cancer in the United States and represents one of the deadliest forms of skin cancer. While recent advances in systemic targeted therapies and immunotherapies have positively impacted melanoma survival, the survival rate of stage IV melanoma remains at a meager 32%. Unfortunately, tumor resistance can impede the effectiveness of these treatments. Oxidative stress is a pivotal player in all stages of melanoma progression, with a somewhat paradoxical function that promotes tumor initiation but hinders vertical growth and metastasis in later disease. As melanoma progresses, it employs adaptive mechanisms to lessen oxidative stress in the tumor environment. Redox metabolic rewiring has been implicated in acquired resistance to BRAF/MEK inhibitors. A promising approach to enhance the response to therapy involves boosting intracellular ROS production using active biomolecules or targeting enzymes that regulate oxidative stress. The complex interplay between oxidative stress, redox homeostasis, and melanomagenesis can also be leveraged in a preventive context. The purpose of this review is to provide an overview of oxidative stress in melanoma, and how the antioxidant system may be manipulated in a therapeutic context for improved efficacy and survival. [ABSTRACT FROM AUTHOR]

Simple Summary: TERT promoter mutations are the most frequent mutations in melanoma, co-occur regularly with BRAF alterations and are associated with a poorer prognosis. Conflicting results have been published on the role of TERT promoter mutations in resistance to targeted therapy in melanoma. Our data suggest that the TERT mRNA level is associated with resistance to BRAF and MEK inhibitors and could therefore be a more reliable marker for prognosis than the promoter mutations. We showed that overexpression of TERT in a V600E-BRAF melanoma cell line drove resistance to BRAF and MEK inhibitors by a mechanism involving the reactivation of the MAPK pathway independently of telomere maintenance. Finally, we established that TERT inhibition is a therapeutic option in V600E-BRAF-mutated melanoma with acquired resistance to BRAF inhibition. Our results demonstrated the diversity of TERT biological activities in melanoma and highlight the therapeutic potential of targeting TERT in these tumors. Because BRAF-mutated melanomas are addicted to the Mitogen Activated Protein Kinase (MAPK) pathway they show a high response rate to BRAF and MEK inhibitors. However, the clinical responses to these inhibitors are often short-lived with the rapid onset of resistance to treatment. Deciphering the molecular mechanisms driving resistance has been the subject of intense research. Recent in vitro and clinical data have suggested a link between expression of telomerase and resistance to targeted therapy in melanoma. TERT promoter mutations are the main mechanism for the continuous upregulation of telomerase in melanoma and co-occur frequently with BRAF alterations. To understand how TERT promoter mutations could be associated with resistance to targeted therapy in melanoma, we conducted translational and in vitro studies. In a cohort of V600E-BRAF-mutated melanoma patients, we showed that the TERT promoter mutation status and TERT expression tended to be associated with response to BRAF and MEK inhibitors. We demonstrated that TERT overexpression in BRAF-mutated melanoma cells reduced sensitivity to BRAF and MEK independently of TERT's telomer maintenance activity. Interestingly, inhibition of TERT reduced growth of BRAF-mutated melanoma including resistant cells. TERT expression in melanoma can therefore be a new biomarker for resistance to MAPK inhibitors as well as a novel therapeutic target. [ABSTRACT FROM AUTHOR]

Dendritic cells have been at the forefront of cancer-immunotherapy research for over 2 decades. They elicited that attention by having an unprecedented capacity to mount T cells responses against tumors. However, the clinical use of DC-based vaccination against established malignancies has resulted in limited clinical benefits. Several factors are responsible for limiting the efficacy of DC-based immunotherapy, such as the harmful influence of the tumor microenvironment on DCs activity. New insights into the inner process of DC-mediated T cell activation have supported the development of new strategies that potentiate DCs-based therapies. Herein, we identify signaling cascades that have recently been targeted by small molecules and biologicals to promote the activation of monocyte-derived DCs and decrease their susceptibility to becoming tolerogenic. While Statins can markedly enhance antigen presentation, protein kinase inhibitors can be used to increase the expression of co-receptors and adhesion molecules. STAT3 and IDO can be modulated to limit the production of regulatory factors that work against differentiation and activation. The targeting of multiple pathways simultaneously has also been found to produce synergism and drastically enhance DCs activity. Some of these strategies have recently yielded positive results in clinical settings against established malignancies such as non-small cell lung cancer. The emergence of these approaches opens the door for a new generation of potent dendritic cell-based therapeutics to fight cancer. [ABSTRACT FROM AUTHOR]

Surufatinib, is a potent inhibitor of vascular endothelial growth factor receptors 1–3; fibroblast growth factor receptor-1; colony-stimulating factor 1 receptor. This Phase 1/1b escalation/expansion study in US patients with solid tumors evaluated 5 once daily (QD) surufatinib doses (3 + 3 design) to identify maximum tolerated dose (MTD), recommended Phase 2 dose (RP2D), and evaluate safety and efficacy at the RP2D in 4 disease-specific expansion cohorts including pancreatic neuroendocrine tumors [pNET] and extrapancreatic NETs [epNET]. MTD and RP2D were 300 mg QD (escalation [n = 35]); 5 patients (15.6%) (Dose Limiting Toxicity [DLT] Evaluable Set [n = 32]) had DLTs. Pharmacokinetics were dose proportional. Estimated progression-free survival (PFS) rates at 11 months were 57.4% (95% confidence interval [CI]: 28.7, 78.2) and 51.1% (95% CI: 12.8, 80.3) for pNET and epNET expansion cohorts, respectively. Median PFS was 15.2 (95% CI: 5.2, not evaluable) and 11.5 (95% CI: 6.5,11.5) months. Response rates were 18.8% and 6.3%. The most frequent treatment-emergent adverse events (both cohorts) were fatigue (46.9%), hypertension (43.8%), proteinuria (37.5%), diarrhea (34.4%). Pharmacokinetics, safety, and antitumor efficacy of 300 mg QD oral surufatinib in US patients with pNETs and epNETs are consistent with previously reported studies in China and may support applicability of earlier surufatinib studies in US patients. Clinical trial registration: Clinicaltrials.gov NCT02549937. [ABSTRACT FROM AUTHOR]

Background: Prognosis for patients with metastatic melanoma has been improved dramatically with the development of BRAF/MEK directed therapy and immune checkpoint inhibition. However, resistance to therapy remains a challenge, particularly with BRAF/MEK targeted therapy which often has a limited duration of efficacy. Pre-clinical data suggest that adding CSF1 inhibition to BRAF/MEK targeted therapy may reduce resistance and increase efficacy. Methods: We performed a phase I/II study to determine the safety and efficacy of CSF1 inhibition with MCS110 in combination with BRAF/MEK inhibition with dabrafenib/trametinib in patients with BRAF V600E/K mutant metastatic melanoma. The trial was terminated early due to a decision by the study sponsor to cease further development of MCS110. Results: Between September 2018 to July 2019 six patients were enrolled on the study. Patients were evenly split between female (50%) and male (50%) with a median age of 59.5 yrs. (26–71). Five patients experienced grade 3 toxicities that were possibly related to one of the therapies, there were no grade 4 or grade 5 events. One patient had a partial response (PR) by RECIST 1.1, one patient had stable disease (SD), 3 patients had disease progression (PD). Median progression free survival was 2.3 months (90% CI: 1.3 mos to not reached). Conclusion: MCS110 in combination with dabrafenib and trametinib was reasonably well tolerated in a small melanoma population. One response was observed in this small sample of patients suggesting this combination might be worthy of further exploration. [ABSTRACT FROM AUTHOR]

Summary: The majority of melanoma patients experience relapse during adjuvant therapy or after the end of therapy. Sixty-one patients from 3 melanoma centres who experienced recurrence and received adjuvant pembrolizumab for resected stage III/IV melanoma were enrolled. Disease characteristics, recurrence characteristics, subsequent management and outcomes were retrospectively analysed. Sixty-one patients were enrolled in this study. The median time to first relapse from the commencement of adjuvant pembrolizumab was 8 months (1–22 months). The first recurrences were locoregional alone in 25 patients (41%), distant alone in 29 (47.5%) and concurrent locoregional and distant relapse in 7 (11.5%). At the first recurrence, 4 patients (80%) who underwent resection alone experienced further relapse of disease. Three (60%) patients who were treated with adjuvant pembrolizumab following surgery, 2 (100%) patients who were treated with adjuvant chemotherapy, 2 (66.7%) patients who were treated with adjuvant chemotherapy and pembrolizumab combined and 3 (100%) patients who were treated with adjuvant radiotherapy and pembrolizumab combined had further recurrence. Of the three patients treated with adjuvant BRAF/MEKi following the first relapse, none had yet recurred. Of the 8 patients treated with pembrolizumab alone, only one patient (12.5%) who recurred after ceasing adjuvant PD1 had a partial response. The overall response rate to BRAF/MEKi was 75%, 3/4; to pembrolizumab in combination with an oral multitargeted receptor tyrosine kinase inhibitor, it was 22.2%, 2/9; to chemotherapeutic agents alone, it was 33.3%, 1/3; and to chemotherapeutic agents combined with pembrolizumab, it was 37.5%, 3/8. The patient treated with imatinib had progressive disease after 3 months of treatment. Of the 6 patients who received temozolomide combined with pembrolizumab, 3 (3/6, 50%) had a partial response. The median OS of the patients who relapsed locoregionally only was longer than that of the patients who relapsed distally at the first recurrence (35 months and 14 months, respectively; P < 0.01). The outcomes of the patients with disease recurrence during or after the completion of 1 year of adjuvant anti-PD1 therapy were poor despite multimodality treatment. [ABSTRACT FROM AUTHOR]

6-Nitrodopamine (6-ND) is released from rat isolated atria being 100 times more potent than noradrenaline and adrenaline, and 10,000 times more potent than dopamine as a positive chronotropic agent. The present study aimed to investigate the interactions of 6-ND with the classical catecholamines, phosphodiesterase (PDE)-3 and PDE4, and the protein kinase A in rat isolated atria. Atrial incubation with 1 pM of dopamine, noradrenaline, or adrenaline had no effect on atrial frequency. Similar results were observed when the atria were incubated with 0.01 pM of 6-ND. However, co-incubation of 6-ND (0.01 pM) with dopamine, noradrenaline, or adrenaline (1 pM each) resulted in significant increases in atrial rate, which persisted over 30 min after washout of the agonists. The increased atrial frequency induced by co-incubation of 6-ND with the catecholamines was significantly reduced by the voltage-gated sodium channel blocker tetrodotoxin (1 µM, 30 min), indicating that the positive chronotropic effect of 6-ND is due in part to activation of nerve terminals. Pre-treatment of the animals with reserpine had no effect on the positive chronotropic effect induced by dopamine, noradrenaline, or adrenaline; however, reserpine markedly reduced the 6-ND (1 pM)-induced positive chronotropic effect. Incubation of the rat isolated atria with the protein kinase A inhibitor H-89 (1 µM, 30 min) abolished the increased atrial frequency induced by dopamine, noradrenaline, and adrenaline, but only attenuated the increases induced by 6-ND. 6-ND induces catecholamine release from adrenergic terminals and increases atrial frequency independently of PKA activation. [ABSTRACT FROM AUTHOR]

Glioblastoma (GB) is the most common malignant primary brain tumor in adults. The standard of care for newly diagnosed GB involves surgical resection followed by radiochemotherapy with temozolomide, with or without tumor‐treating fields. In recent years, various efforts have been made to identify suitable molecularly targeted treatment options for malignant brain tumors. This meta‐analysis provides an overview of recently published randomized controlled trials (RCTs) with and without molecular stratification, analyzing targeted agents in patients with newly diagnosed GB. The Cochrane Library, MEDLINE (Ovid), ClinicalTrials.gov, WHO's International Clinical Trials Registry Platform, and Google Scholar were searched for RCTs on targeted therapies in patients with newly diagnosed glioblastoma. Hazard ratios (HRs) for overall survival (OS) and progression‐free survival (PFS) were extracted and pooled in a random‐effects meta‐analysis. Twelve RCTs (n = 3941 patients) involving protein kinase inhibitors, proteasome and histone deacetylase inhibitors, anti‐angiogenic approaches and poly (ADP‐ribose) polymerase (PARP) inhibitors were included in the meta‐analysis. None of the targeted agents achieved a significant benefit with regard to OS (HR = 0.98 [95% confidence interval (CI) 0.86‐1.11, P =.7731]). By comparison, targeted therapy showed a benefit for PFS (HR = 0.83 [95% CI 0.74‐0.94, P =.0037]), especially for patients with an unmethylated O6‐methylguanine‐DNA‐methyltransferase (MGMT) promoter (0.75 [95% CI 0.56‐0.99, P =.0440]). Prolongation of PFS was largely driven by VEGF inhibition with bevacizumab (HR = 0.70 [95% CI 0.61‐0.80, P =.0000]). VEGF inhibition with bevacizumab prolonged PFS in patients with newly diagnosed glioblastoma compared to standard care. However, no improvement in OS was observed with any of the targeted agents. [ABSTRACT FROM AUTHOR]

Marine organisms are subjected to pathogens and xenobiotics in their natural ecosystem. The objective of this study was to test the role of hemocytes in Anadara notabilis subjected to cadmium chloride pollution. The clams were collected from the Mediterranean Sea off Alexandria, Egypt, in summer and winter 2019 for morphological and immunocytotoxic studies. Sodium Dodecyl sulfate polyacrylamide gel electrophoresis was carried out to separate the proteins of hemolymph lysate. Immunodetection was performed with anti-inducible and anti-endothelial nitric oxide synthesis and anti-p105 antibody. Nitric oxide production in hemocytes was tested. Nucleic acids were extracted and quantified. Clams subjected to cadmium chloride pollution (100 µg/L, 250 µg/L and 500 µg/L) showed a multifocal inflammatory reaction in the columnar epithelia and the connective tissue with mantle retraction in an active encapsulation. During summer hemocytes incubated with interleukin-2 released more nitric oxide than control cells while the use of the protein kinase C inhibitor caused a slight increase in the nitric oxide synthesis compared to hemocytes incubated in interleukin-2. The use of monoclonal antibodies in hemocytes lysate incubated with the different inducers revealed the presence of 140 and 145 kDa bands in both control and treated clams during summer and winter. The proportion of SH hemocytes (spreading cells with phagocytic activities) exceeded that of RH cells (round cells with non-phagocytic activities) in summer and winter. During winter, the DNA fragments appeared characteristic of apoptosis. This study concludes that interleukin-2 causes notable increases in NO production irrespective of season. During summer hemocytes produce an amount of NO double than those observed during winter. [ABSTRACT FROM AUTHOR]

The mechanistic target of rapamycin complex 1 (mTORC1) integrates growth, nutrient and energy status cues to control cell growth and metabolism. While mTORC1 activation at the lysosome is well characterized, it is not clear how this complex is regulated at other subcellular locations. Here, we combine location-selective kinase inhibition, live-cell imaging and biochemical assays to probe the regulation of growth factor-induced mTORC1 activity in the nucleus. Using a nuclear targeted Akt Substrate-based Tandem Occupancy Peptide Sponge (Akt-STOPS) that we developed for specific inhibition of Akt, a critical upstream kinase, we show that growth factor-stimulated nuclear mTORC1 activity requires nuclear Akt activity. Further mechanistic dissection suggests that nuclear Akt activity mediates growth factor-induced nuclear translocation of Raptor, a regulatory scaffolding component in mTORC1, and localization of Raptor to the nucleus results in nuclear mTORC1 activity in the absence of growth factor stimulation. Taken together, these results reveal a mode of regulation of mTORC1 that is distinct from its lysosomal activation, which controls mTORC1 activity in the nuclear compartment.

BackgroundPerturbation of the CDK4/6 pathway is frequently observed in advanced bladder cancer. We investigated the potential of targeting this pathway alone or in combination with chemotherapy or immunotherapy as a therapeutic approach for the treatment of bladder cancer METHODS: The genetic alterations of the CDK4/6 pathway in bladder cancer were first analyzed with The Cancer Genome Atlas database and validated in our bladder cancer patient-derived tumor xenografts (PDXs). Bladder cancer cell lines and mice carrying PDXs with the CDK4/6 pathway perturbations were treated with a CDK4/6 inhibitor palbociclib to determine its anticancer activity and the underlying mechanisms. The combination index method was performed to assess palbociclib and gemcitabine drug-drug interactions. Syngeneic mouse bladder cancer model BBN963 was used to assess whether palbociclib could potentiate anti-PD1 immunotherapy.ResultsOf the 413 bladder cancer specimens, 79.2% harbored pertubations along the CDK4/6 pathway. Palbociclib induced G0/G1 cell cycle arrest but with minimal apoptosis in vitro. In mice carrying PDXs, palbociclib treatment reduced tumor growth and prolonged survival from 14 to 32 days compared to vehicle only controls (p = 0.0001). Palbociclib treatment was associated with a decrease in Rb phosphorylation in both cell lines and PDXs. Palbociclib and gemcitabine exhibited antagonistic cytotoxicity in vitro (CI > 3) and in vivo, but palbociclib significantly enhanced the treatment efficacy of anti-PD1 immunotherapy and induced CD8+ T lymphocyte infiltration in syngeneic mouse models.ConclusionsThe CDK4/6 pathway is feasible as a potential target for the treatment of bladder cancer, especially in combination with immunotherapy. A CDK4/6 inhibitor should not be combined with gemcitabine.

Loss of the tumor suppressor NF1 leads to activation of RAS effector pathways, which are therapeutically targeted by inhibition of mTOR (mTORi) or MEK (MEKi). However, therapeutic inhibition of RAS effectors leads to the development of drug resistance and ultimately disease progression. To investigate molecular signatures in the context of NF1 loss and subsequent acquired drug resistance, we analyzed the exomes, transcriptomes, and kinomes of Nf1-mutant mouse tumor cell lines and derivatives of these lines that acquired resistance to either MEKi or mTORi. Biochemical comparisons of this unique panel of tumor cells, all of which arose in Nf1+/- mice, indicate that loss of heterozygosity of Nf1 as an initial genetic event does not confer a common biochemical signature or response to kinase inhibition. Although acquired drug resistance by Nf1-mutant tumor cells was accompanied by altered kinomes and irreversibly altered transcriptomes, functionally in multiple Nf1-mutant tumor cell lines, MEKi resistance was a stable phenotype, in contrast to mTORi resistance, which was reversible. Collectively, these findings demonstrate that Nf1-mutant tumors represent a heterogeneous group biochemically and undergo broader remodeling of kinome activity and gene expression in response to targeted kinase inhibition.

Lessons learnedThe results from the liposarcoma cohort of SARC024 confirm previously published data and do not support the routine use of regorafenib in this patient population. Continued exploration of novel therapies, including combination approaches, is warranted for a patient population in whom limited treatment options exist.BackgroundRegorafenib is a multitargeted kinase inhibitor with a kinase profile overlapping, but distinct from, pazopanib, an agent approved for recurrent and metastatic non-gastrointestinal stromal tumor (GIST), non-adipocytic soft tissue sarcoma. We conducted a randomized, phase II study of regorafenib versus placebo in refractory liposarcoma patients.MethodsPatients with advanced or metastatic, treatment-refractory liposarcoma were randomized 1:1 to receive regorafenib 160 mg or placebo once daily (3 weeks on, 1 week off). Patients with well-differentiated liposarcoma only were excluded. Crossover for placebo was allowed upon progression. The primary endpoint was progression-free survival (PFS), according to RECIST version 1.1.ResultsForty-eight subjects with liposarcoma (34 dedifferentiated, 12 myxoid/round cell, 2 pleomorphic) were enrolled. Median PFS was 1.87 (95% confidence interval [CI], 0.92-3.67) months for regorafenib versus 2.07 (95% CI, 1.64-3.44) months for placebo; stratified hazard ratio [HR], 0.85 (95% CI, 0.46, 1.58), p = .62. No responses were seen on regorafenib. One PR was observed on placebo. Median overall survival was 6.46 (95% CI, 4.16-23.48) months for regorafenib and 4.89 (95% CI, 3.02-9.77) months for placebo, stratified HR, 0.66 (95% CI, 0.31-1.40), p = .28). Treatment-related adverse events were similar to the known safety profile of regorafenib.ConclusionRegorafenib did not appear to improve PFS in treatment-refractory liposarcoma. No new significant safety signals were observed.

BACKGROUND: Brutons tyrosine kinase (BTK) is important in B-cell signalling. Efficacy has been reported for BTK inhibitors (BTKi) in human autoimmune diseases. Canine pemphigus foliaceus (cPF) is one of the most common canine autoimmune skin diseases. OBJECTIVES: To determine the safety and efficacy of the BTKi PRN1008 in the treatment of cPF. ANIMALS: Four privately owned dogs. METHODS AND MATERIALS: Four dogs diagnosed with PF were administered BTKi PRN1008. Initial dosages approximated to 15 mg/kg once daily, increased to twice daily if inadequate response was seen. Treatment continued for 20 weeks, attempting to decrease to every other day. Dogs were monitored with complete blood counts, serum biochemistry panels and urinalyses, and evaluated with a modified version of a validated human Pemphigus Disease Activity Index (cPDAI). Serum anti-desmocollin-1 (DSC-1) and desmoglein-1 (DSG-1) immunoglobulin (Ig)G titres were performed before and after the treatment period. Drug bound to target was measured in peripheral blood mononuclear cells (PBMC). RESULTS: All four dogs showed reduction in lesions and cPDAI score during the first two weeks of treatment. Three dogs continued to improve and sustained near complete remission by 20 weeks, at which point three responses were considered good and one fair. Final daily dosages were in the range 17-33 mg/kg. Anti-DSC-1 IgG titre decreased dramatically in one dog, was undetectable in two and was uninterpretable in one dog. No dogs had detectable IgG to DSG1. A possible adverse event occurred in one dog. CONCLUSIONS AND CLINICAL IMPORTANCE: BTKi PRN1008 monotherapy may have some beneficial effects in some cases of cPF.

ObjectiveSomatic HER2 mutations occur in ~5% of cervical cancers and are considered oncogenic and associated with poor prognosis. Neratinib, an irreversible pan-HER tyrosine kinase inhibitor, is active in multiple HER2-mutant cancers. SUMMIT is a phase II basket trial investigating the efficacy and safety of neratinib in solid tumors.MethodsPatients with HER2-mutant, persistent, metastatic/recurrent cervical cancer with disease progression after platinum-based treatment for advanced/recurrent disease received oral neratinib 240 mg/day with mandatory loperamide prophylaxis during cycle 1. The primary endpoint was confirmed objective response rate (ORR). Secondary endpoints included: response duration (DOR); clinical benefit rate (CBR); progression-free survival (PFS); overall survival (OS); safety.ResultsSixteen eligible patients were enrolled; 10 (62.5%) had endocervical adenocarcinoma. The most common HER2 mutation was S310F (63% of patients). Three of 12 RECIST-measurable patients had confirmed partial responses (ORR 25%; 95%CI 5.5-57.2%); 3 had stable disease ≥16 weeks (CBR 50%; 95%CI 21.1-78.9%). DOR for responders were 5.6, 5.9, and 12.3 months. Median PFS was 7.0 months (95%CI 0.7-18.3 months); median OS was 16.8 months (95%CI 4.1-NE months). Diarrhea (75%), nausea (44%), and decreased appetite (38%) were the most common adverse events. One patient (6%) reported grade 3 diarrhea. There were no grade 4 events, and no diarrhea-related treatment discontinuations.ConclusionsNeratinib monotherapy showed evidence of activity in heavily pretreated patients with HER2-mutant cervical cancer, with no new safety signals. Given the few effective options for cervical cancer after platinum-based therapy failure, neratinib warrants further investigation in this molecularly defined patient population.Trial registration numberNCT01953926 (ClinicalTrials.gov), 2013-002872-42 (EudraCT).

ObjectiveTo investigate the anti-tumor effect of a newly-developed dual inhibitor (APCS-540) of glycogen synthase kinase 3 beta (GSK3B) and histone deacetylases (HDACs) in ovarian cancer cells.MethodsThe effects of APCS-540 on cancer cell proliferation, migration, invasion and cancer stemness were investigated in vitro in human (KURAMOCHI, OVCA420, OVSAHO) and mouse (BR-Luc, ID8, MOSE-HRas-Myc) ovarian cancer cells. Cisplatin-sensitive (A2780) and cisplatin-resistant (A2780cis) cell lines were used to evaluate APCS-540's effect on chemoresistance. The immunocompetent syngeneic mouse model BR-Luc was used to test the effect of APCS-540 on ovarian cancer progression and survival.ResultsAPCS-540 showed significant anti-tumor effects in vitro in both human and mouse ovarian cancer cells. Importantly, APCS-540 demonstrated marked cytotoxicity against cisplatin-resistant cancer cells and reversed cisplatin-resistance when used in combination with platinum. APCS-540 significantly decreased cancer cell invasion. A significant 66% increase in survival was observed in mice treated with APCS-540 compared to control mice.ConclusionDual inhibition of GSK3B and HDACs via APCS-540 showed potent anti-tumor activity in vitro and in vivo, suggesting that APCS-540 may provide a novel treatment option for ovarian cancer, including the platinum-resistant disease.

ObjectiveTo assess the safety and efficacy of a novel Wnt pathway modulator, lorecivivint (SM04690), for treating pain and inhibiting structural progression in moderately to severely symptomatic knee osteoarthritis (OA).MethodsSubjects in this 52-week, phase IIa, multicenter, randomized, double-blind, placebo-controlled, dose-ranging trial received a single 2-ml intraarticular injection of lorecivivint (dose of 0.03 mg, 0.07 mg, or 0.23 mg) or placebo. Efficacy was assessed based on change from baseline on the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) score subscales for pain and function (scale 0-100 for each) and change from baseline in the radiographic medial joint space width (JSW). Baseline-adjusted analysis of covariance with multiple imputation was performed separately to evaluate efficacy. This proof-of-concept study evaluated the intent-to-treat population as well as a prespecified group of subjects with unilateral symptoms of knee OA (designated UNI) and an additional post hoc subgroup of subjects with unilateral symptoms but without widespread pain (designated UNI WP-).ResultsIn this trial, 455 subjects were randomized to a treatment group. The primary end point, significant improvement in the WOMAC pain score compared with placebo at week 13, was not met by any lorecivivint dose group (mean ± SD change from baseline, -23.3 ± 2.2 in the 0.03 mg group, -23.5 ± 2.1 in the 0.07 mg group, -21.3 ± 2.2 in the 0.23 mg group, and -22.1 ± 2.1 in the placebo group; each P > 0.05 versus placebo). All groups (including placebo) demonstrated clinically meaningful (≥20-point) improvements from baseline in the WOMAC pain score. The durability of response was evaluated through week 52. In the prespecified UNI group and post hoc UNI WP- group at week 52, treatment with 0.07 mg lorecivivint significantly improved the WOMAC pain score (between-group difference versus placebo, -8.73, 95% confidence interval [95% CI] -17.44, -0.03 [P = 0.049] and -11.21, 95% CI -20.99, -1.43 [P = 0.025], respectively) and WOMAC function score (between-group difference versus placebo, -10.26, 95% CI -19.82, -0.69 [P = 0.036] and -13.38, 95% CI -24.33, -2.43 [P = 0.017], respectively). Relative to baseline, the mean change in the medial JSW at week 52 was -0.04 mm in the 0.03 mg cohort, -0.09 mm in the 0.07 mg cohort, -0.16 mm in the 0.23 mg cohort, and -0.14 mm in the placebo cohort; no treatment group achieved a significant change in medial JSW compared with placebo at week 52. In both unilateral symptom subgroups, the 0.07 mg lorecivivint dose significantly increased medial JSW compared with placebo at week 52 (medial JSW 0.39 mm, 95% CI 0.06, 0.72 in the UNI group [P = 0.021] and 0.42 mm, 95% CI 0.04, 0.80 in the UNI WP- group [P = 0.032]). Changes observed in the 0.03 mg and 0.23 mg dose groups were not significantly different from those in the placebo group for any of these measures. Lorecivivint appeared safe and well tolerated.ConclusionThis phase IIa, proof-of-concept trial in patients with symptomatic knee OA did not meet its primary end point. Nevertheless, the study identified a target population in whom to evaluate the potential efficacy of lorecivivint for the treatment of knee OA.

Progression on therapy in non-small cell lung carcinoma (NSCLC) is often evaluated radiographically, however, image-based evaluation of said therapies may not distinguish disease progression due to intrinsic tumor drug resistance or inefficient tumor penetration of the drugs. Here we report that the inhibition of mutated EGFR promotes the secretion of a potent vasoconstrictor, endothelin-1 (EDN1), which continues to increase as the cells become resistant with a mesenchymal phenotype. As EDN1 and its receptor (EDNR) is linked to cancer progression, EDNR-antagonists have been evaluated in several clinical trials with disappointing results. These trials were based on a hypothesis that the EDN1-EDNR axis activates the MAPK-ERK signaling pathway that is vital to the cancer cell survival; the trials were not designed to evaluate the impact of tumor-derived EDN1 in modifying tumor microenvironment or contributing to drug resistance. Ectopic overexpression of EDN1 in cells with mutated EGFR resulted in poor drug delivery and retarded growth in vivo but not in vitro. Intratumoral injection of recombinant EDN significantly reduced blood flow and subsequent gefitinib accumulation in xenografted EGFR-mutant tumors. Furthermore, depletion of EDN1 or the use of endothelin receptor inhibitors bosentan and ambrisentan improved drug penetration into tumors and restored blood flow in tumor-associated vasculature. Correlatively, these results describe a simplistic endogenous yet previously unrealized resistance mechanism inherent to a subset of EGFR-mutant NSCLC to attenuate tyrosine kinase inhibitor delivery to the tumors by limiting drug-carrying blood flow and the drug concentration in tumors. SIGNIFICANCE: EDNR antagonists can be repurposed to improve drug delivery in VEGFA-secreting tumors, which normally respond to TKI treatment by secreting EDN1, promoting vasoconstriction, and limiting blood and drug delivery.

IntroductionApproximately 4% of NSCLC harbor BRAF mutations, and approximately 50% of these are non-V600 mutations. Treatment of tumors harboring non-V600 mutations is challenging because of functional heterogeneity and lack of knowledge regarding their clinical significance and response to targeted agents.MethodsWe conducted an integrative analysis of BRAF non-V600 mutations using genomic profiles of BRAF-mutant NSCLC from the Guardant360 database. BRAF mutations were categorized by clonality and class (1 and 2: RAS-independent; 3: RAS-dependent). Cell viability assays were performed in Ba/F3 models. Drug screens were performed in NSCLC cell lines.ResultsA total of 305 unique BRAF mutations were identified. Missense mutations were most common (276, 90%), and 45% were variants of unknown significance. F468S and N581Y were identified as novel activating mutations. Class 1 to 3 mutations had higher clonality than mutations of unknown class (p < 0.01). Three patients were treated with MEK with or without BRAF inhibitors. Patients harboring G469V and D594G mutations did not respond, whereas a patient with the L597R mutation had a durable response. Trametinib with or without dabrafenib, LXH254, and lifirafenib had more potent inhibition of BRAF non-V600-mutant NSCLC cell lines than other MEK, BRAF, and ERK inhibitors, comparable with the inhibition of BRAF V600E cell line.ConclusionsIn BRAF-mutant NSCLC, clonality is higher in known functional mutations and may allow identification of variants of unknown significance that are more likely to be oncogenic drivers. Our data indicate that certain non-V600 mutations are responsive to MEK and BRAF inhibitors. This integration of genomic profiling and drug sensitivity may guide the treatment for BRAF-mutant NSCLC.

Preclinical modeling suggests that intermittent BRAF inhibitor therapy may delay acquired resistance when blocking oncogenic BRAFV600 in melanoma1,2. We conducted S1320, a randomized, open-label, phase 2 clinical trial (NCT02196181) evaluating whether intermittent dosing of the BRAF inhibitor dabrafenib and the MEK inhibitor trametinib improves progression-free survival in patients with metastatic and unresectable BRAFV600 melanoma. Patients were enrolled at 68 academic and community sites nationally. All patients received continuous dabrafenib and trametinib during an 8-week lead-in period, after which patients with non-progressing tumors were randomized to either continuous or intermittent dosing of both drugs on a 3-week-off, 5-week-on schedule. The trial has completed accrual and 206 patients with similar baseline characteristics were randomized 1:1 to the two study arms (105 to continuous dosing, 101 to intermittent dosing). Continuous dosing yielded a statistically significant improvement in post-randomization progression-free survival compared with intermittent dosing (median 9.0 months versus 5.5 months, P = 0.064, pre-specified two-sided α = 0.2). Therefore, contrary to the initial hypothesis, intermittent dosing did not improve progression-free survival in patients. There were no differences in the secondary outcomes, including overall survival and the overall incidence of treatment-associated toxicity, between the two groups.

Background and objectiveGilteritinib is a novel, highly selective tyrosine kinase inhibitor approved in the USA, Canada, Europe, Brazil, Korea, and Japan for the treatment of FLT3 mutation-positive acute myeloid leukemia. This article describes the clinical pharmacokinetic profile of gilteritinib.MethodsThe pharmacokinetic profile of gilteritinib was assessed from five clinical studies.ResultsDose-proportional pharmacokinetics was observed following once-daily gilteritinib administration (dose range 20-450 mg). Median maximum concentration was reached 2-6 h following single and repeat dosing of gilteritinib; mean elimination half-life was 113 h. Elimination was primarily via feces. Exposure to gilteritinib was comparable under fasted and fed conditions. Gilteritinib is primarily metabolized via cytochrome P450 (CYP) 3A4; coadministration of gilteritinib with itraconazole (a strong P-glycoprotein inhibitor and CYP3A4 inhibitor) or rifampicin (a strong P-glycoprotein inducer and CYP3A inducer) significantly affected the gilteritinib pharmacokinetic profile. No clinically relevant interactions were observed when gilteritinib was coadministered with midazolam (a CYP3A4 substrate) or cephalexin (a multidrug and toxin extrusion 1 substrate). Unbound gilteritinib exposure was similar between subjects with hepatic impairment and normal hepatic function.ConclusionsGilteritinib exhibits a dose-proportional pharmacokinetic profile in healthy subjects and in patients with relapsed/refractory acute myeloid leukemia. Gilteritinib exposure is not significantly affected by food. Moderate-to-strong CYP3A inhibitors demonstrated a significant effect on gilteritinib exposure. Coadministration of gilteritinib with CYP3A4 or multidrug and toxin extrusion 1 substrates did not impact substrate concentrations. Unbound gilteritinib was comparable between subjects with hepatic impairment and normal hepatic function; dose adjustment is not warranted for patients with hepatic impairment.Clinical trial registrationNCT02014558, NCT02456883, NCT02571816.

BackgroundPalbociclib is highly active in oestrogen-receptor positive (ER+) metastatic breast cancer, but neutropenia is dose limiting. The goal of this study was to determine whether early neutropenia is associated with disease response to single-agent palbociclib.MethodsBlood count and disease-response data were analysed from two Phase 2 clinical trials at different institutions using single-agent palbociclib: advanced solid tumours positive for retinoblastoma protein and advanced liposarcoma. The primary endpoint was PFS. The primary exposure variable was the nadir absolute neutrophil count (ANC) during the first two cycles of treatment.ResultsOne hundred and ninety-six patients (61 breast, 135 non-breast) were evaluated between the two trials. Development of any grade neutropenia was significantly associated with longer median PFS in both the breast cancer (HR 0.29, 95% CI 0.11-0.74, p = 0.010) and non-breast cancer (HR 0.57, 95% CI 0.38-0.85, p = 0.006) cohorts. Grade 3-4 neutropenia was significantly associated with prolonged PFS in the non-breast cohort (HR 0.57, 95% CI 0.38-0.85, p = 0.006) but not in the breast cohort (HR 0.87, 95% CI 0.51-1.47, p = 0.596). Multivariate analysis yielded similar results.ConclusionsTreatment-related neutropenia in the first two cycles was significantly and independently associated with prolonged PFS, suggesting that neutropenia may be a useful pharmacodynamic marker to guide individualised palbociclib dosing.Clinical trials registration informationBasket Trial: NCT01037790; Sarcoma Trial: NCT01209598.

PurposeThe phase III CELESTIAL study demonstrated improved overall survival (OS) and progression-free survival (PFS) with cabozantinib versus placebo in patients with previously treated, advanced hepatocellular carcinoma (HCC). We analyzed outcomes by baseline alpha-fetoprotein (AFP) and on-treatment AFP changes.Patients and methodsSerum AFP was measured every 8 weeks by blinded, centralized testing. Outcomes were analyzed by baseline AFP bifurcated at 400 ng/mL and by on-treatment AFP response (≥20% decrease from baseline at Week 8). The optimal cutoff for change in AFP at Week 8 was evaluated using maximally selected rank statistics.ResultsMedian OS for cabozantinib versus placebo was 13.9 versus 10.3 months [HR, 0.81; 95% confidence interval (CI), 0.62-1.04] for patients with baseline AFP

BACKGROUND: RET mutations occur in 70% of medullary thyroid cancers, and RET fusions occur rarely in other thyroid cancers. In patients with RET-altered thyroid cancers, the efficacy and safety of selective RET inhibition are unknown. METHODS: We enrolled patients with RET-mutant medullary thyroid cancer with or without previous vandetanib or cabozantinib treatment, as well as those with previously treated RET fusion-positive thyroid cancer, in a phase 1-2 trial of selpercatinib. The primary end point was an objective response (a complete or partial response), as determined by an independent review committee. Secondary end points included the duration of response, progression-free survival, and safety. RESULTS: In the first 55 consecutively enrolled patients with RET-mutant medullary thyroid cancer who had previously received vandetanib, cabozantinib, or both, the percentage who had a response was 69% (95% confidence interval [CI], 55 to 81), and 1-year progression-free survival was 82% (95% CI, 69 to 90). In 88 patients with RET-mutant medullary thyroid cancer who had not previously received vandetanib or cabozantinib, the percentage who had a response was 73% (95% CI, 62 to 82), and 1-year progression-free survival was 92% (95% CI, 82 to 97). In 19 patients with previously treated RET fusion-positive thyroid cancer, the percentage who had a response was 79% (95% CI, 54 to 94), and 1-year progression-free survival was 64% (95% CI, 37 to 82). The most common adverse events of grade 3 or higher were hypertension (in 21% of the patients), increased alanine aminotransferase level (in 11%), increased aspartate aminotransferase level (in 9%), hyponatremia (in 8%), and diarrhea (in 6%). Of all 531 patients treated, 12 (2%) discontinued selpercatinib owing to drug-related adverse events. CONCLUSIONS: In this phase 1-2 trial, selpercatinib showed durable efficacy with mainly low-grade toxic effects in patients with medullary thyroid cancer with and without previous vandetanib or cabozantinib treatment. (Funded by Loxo Oncology and others; LIBRETTO-001 ClinicalTrials.gov number, NCT03157128.).

BackgroundRET fusions are oncogenic drivers in 1 to 2% of non-small-cell lung cancers (NSCLCs). In patients with RET fusion-positive NSCLC, the efficacy and safety of selective RET inhibition are unknown.MethodsWe enrolled patients with advanced RET fusion-positive NSCLC who had previously received platinum-based chemotherapy and those who were previously untreated separately in a phase 1-2 trial of selpercatinib. The primary end point was an objective response (a complete or partial response) as determined by an independent review committee. Secondary end points included the duration of response, progression-free survival, and safety.ResultsIn the first 105 consecutively enrolled patients with RET fusion-positive NSCLC who had previously received at least platinum-based chemotherapy, the percentage with an objective response was 64% (95% confidence interval [CI], 54 to 73). The median duration of response was 17.5 months (95% CI, 12.0 to could not be evaluated), and 63% of the responses were ongoing at a median follow-up of 12.1 months. Among 39 previously untreated patients, the percentage with an objective response was 85% (95% CI, 70 to 94), and 90% of the responses were ongoing at 6 months. Among 11 patients with measurable central nervous system metastasis at enrollment, the percentage with an objective intracranial response was 91% (95% CI, 59 to 100). The most common adverse events of grade 3 or higher were hypertension (in 14% of the patients), an increased alanine aminotransferase level (in 12%), an increased aspartate aminotransferase level (in 10%), hyponatremia (in 6%), and lymphopenia (in 6%). A total of 12 of 531 patients (2%) discontinued selpercatinib because of a drug-related adverse event.ConclusionsSelpercatinib had durable efficacy, including intracranial activity, with mainly low-grade toxic effects in patients with RET fusion-positive NSCLC who had previously received platinum-based chemotherapy and those who were previously untreated. (Funded by Loxo Oncology and others; LIBRETTO-001 ClinicalTrials.gov number, NCT03157128.).

BackgroundCombined targeting of CDK4/6 and ER is now the standard of care for patients with advanced ER+/HER2- breast cancer. However, acquired resistance to these therapies frequently leads to disease progression. As such, it is critical to identify the mechanisms by which resistance to CDK4/6-based therapies is acquired and also identify therapeutic strategies to overcome resistance.MethodsIn this study, we developed and characterized multiple in vitro and in vivo models of acquired resistance to CDK4/6-based therapies. Resistant models were screened by reverse phase protein array (RPPA) for cell signaling changes that are activated in resistance.ResultsWe show that either a direct loss of Rb or loss of dependence on Rb signaling confers cross-resistance to inhibitors of CDK4/6, while PI3K/mTOR signaling remains activated. Treatment with the p110α-selective PI3K inhibitor, alpelisib (BYL719), completely blocked the progression of acquired CDK4/6 inhibitor-resistant xenografts in the absence of continued CDK4/6 inhibitor treatment in models of both PIK3CA mutant and wild-type ER+/HER2- breast cancer. Triple combination therapy against PI3K:CDK4/6:ER prevented and/or delayed the onset of resistance in treatment-naive ER+/HER2- breast cancer models.ConclusionsThese data support the clinical investigation of p110α-selective inhibitors of PI3K, such as alpelisib, in patients with ER+/HER2- breast cancer who have progressed on CDK4/6:ER-based therapies. Our data also support the investigation of PI3K:CDK4/6:ER triple combination therapy to prevent the onset of resistance to the combination of endocrine therapy plus CDK4/6 inhibition.

The network-based proximity between drug targets and disease genes can provide novel insights regarding the repercussions, interplay, and repositioning of drugs in the context of disease. Current understanding and treatment for reversing of the fibrotic process is limited in systemic sclerosis (SSc). We have developed a network-based analysis for drug effects that takes into account the human interactome network, proximity measures between drug targets and disease-associated genes, genome-wide gene expression and disease modules that emerge through pertinent analysis. Currently used and potential drugs showed a wide variation in proximity to SSc-associated genes and distinctive proximity to the SSc-relevant pathways, depending on their class and targets. Tyrosine kinase inhibitors (TyKIs) approach disease gene through multiple pathways, including both inflammatory and fibrosing processes. The SSc disease module includes the emerging molecular targets and is in better accord with the current knowledge of the pathophysiology of the disease. In the disease-module network, the greatest perturbing activity was shown by nintedanib, followed by imatinib, dasatinib, and acetylcysteine. Suppression of the SSc-relevant pathways and alleviation of the skin fibrosis was remarkable in the inflammatory subsets of the SSc patients receiving TyKI therapy. Our results show that network-based drug-disease proximity offers a novel perspective into a drug's therapeutic effect in the SSc disease module. This could be applied to drug combinations or drug repositioning, and be helpful guiding clinical trial design and subgroup analysis.

BACKGROUND: Regorafenib is an inhibitor of multiple kinases with aberrant expression and activity in neuroblastoma tumours that have potential roles in neuroblastoma pathogenesis. METHODS: We evaluated neuroblastoma cells treated with regorafenib for cell viability and confluence, and analysed treated cells for apoptosis and cell cycle progression. We evaluated the efficacy of regorafenib in vivo using an orthotopic xenograft model. We evaluated regorafenib-mediated inhibition of kinase targets and performed reverse-phase protein array (RPPA) analysis of neuroblastoma cells treated with regorafenib. Lastly, we evaluated the efficacy and effects of the combination of regorafenib and 13-cis-retinoic acid on intracellular signalling. RESULTS: Regorafenib treatment resulted in reduced neuroblastoma cell viability and confluence, with both induction of apoptosis and of cell cycle arrest. Regorafenib treatment inhibits known receptor tyrosine kinase targets RET and PDGFRβ and intracellular signalling through the RAS/MAPK, PI3K/Akt/mTOR and Fos/Jun pathways. Regorafenib is effective against neuroblastoma tumours in vivo, and the combination of regorafenib and 13-cis-retinoic acid demonstrates enhanced efficacy compared with regorafenib alone. CONCLUSIONS: The effects of regorafenib on multiple intracellular signalling pathways and the potential additional efficacy when combined with 13-cis-retinoic acid represent opportunities to develop treatment regimens incorporating regorafenib for children with neuroblastoma.