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PURPOSE: Tenosynovial giant cell tumor (TGCT) is a locally aggressive neoplasm caused by dysregulation of the colony-stimulating factor 1 (CSF1) gene and overexpression of the CSF1 ligand. Surgery is the standard of care for most patients, but there are limited treatment options for patients with TGCT not amenable to surgery. This study evaluates vimseltinib, an investigational, oral, switch-control tyrosine kinase inhibitor designed to selectively and potently inhibit the CSF1 receptor. PATIENTS AND METHODS: This first-in-human, multicenter, open-label phase I/II study of vimseltinib in patients with malignant solid tumors (N = 37) or TGCT not amenable to surgery (N = 32) followed a pharmacologically guided 3 + 3 study design (NCT03069469). The primary objectives were to assess safety and tolerability, determine the recommended phase II dose, and characterize the pharmacokinetics; exploratory objectives included pharmacodynamics and efficacy. RESULTS: Vimseltinib was well tolerated; the majority of non-laboratory treatment-emergent adverse events were of grade 1/2 severity. There was no evidence of cholestatic hepatotoxicity or drug-induced liver injury. The recommended phase II dose was determined to be 30 mg twice weekly (no loading dose), and vimseltinib plasma exposure increased with the dose. In patients with TGCT, the median treatment duration was 25.1 months (range, 0.7-46.9), and the objective response rate as assessed by independent radiological review using RECIST version 1.1 was 72%. CONCLUSIONS: Vimseltinib demonstrated long-term tolerability, manageable safety, dose-dependent exposure, and robust antitumor activity in patients with TGCT not amenable to surgery.

BACKGROUND: Most patients with metastatic gastroesophageal adenocarcinoma (mGEA) progress on immune checkpoint inhibitors (ICIs). Novel approaches to overcome resistance to ICI in mGEA are needed. Cabozantinib is a multi-tyrosine kinase inhibitor thought to enhance the immunomodulatory effects of ICI. This study evaluated the combination of cabozantinib and pembrolizumab in ICI refractory or resistant mGEA. METHODS: Investigator-initiated, single-arm, single institution, and phase II study in patients with mGEA. Patients had progressed on ICI and/or had PD-L1 CPS score ≤10%. Cabozantinib dose was 40 mg p.o. daily on days 1-21 of a 21-day cycle, with pembrolizumab 200 mg i.v. on day 1. The primary endpoint was progression-free survival at 6 months (PFS-6). RESULTS: Twenty-seven patients were enrolled. Median age 58 years (24-87), female (n = 14), ECOG 0/1 = 13/14, GC/GEJ = 16/11, and non-Hispanic White/Hispanic/Asian = 12/8/7. The primary endpoint was met. After a median follow-up of 31.4 months (range 3.3-42.5), PFS-6 was 22.2% (95% CI 9.0-39.0). The median PFS and OS are 2.3 months (95% CI 1.7-4.1) and 5.5 months (3.1-14.0), respectively. The most common mutations were TP53 (78.3%) and CDH1/PIK3CA/CTNNB1 (17.4% each). The most common grade (G) treatment-related adverse events (TRAE) were diarrhea (25.9%), fatigue (18.5%), hypertension, and muscle cramps (14.8% each). G3-4 TRAE were seen in n = 3 patients (hypertension, thromboembolic event, esophageal perforation; each n = 1). No G5 was observed. CONCLUSIONS: The addition of cabozantinib to pembrolizumab shows clinical benefit in ICI-resistant or refractory mGEA with a tolerable safety profile. (ClinicalTrials.gov Identifier: NCT04164979. IRB Approved: UCI 18-124, University of California Irvine IRB#20195426.).

Drug development is complex and costly. Clinical trial participants take on risks, making it essential to maximize trial efficiency and maintain participant safety. Identifying periods of excessive burden during drug development can inform trial design, ensure patient benefit and prevent harm. This study aims to examine all published clinical trials for cabozantinib to assess patient benefit and burden over time. We conducted a retrospective cross-sectional review of interventional clinical trials of cabozantinib for solid cancer treatment. We searched PubMed/MEDLINE, Embase, Cochrane (CENTRAL) and ClinicalTrials.gov. We extracted adverse event rates, median progression-free survival (PFS), median overall survival and objective response rate (ORR) for each included trial. We calculated frequencies of trial characteristics, cumulative grade 3-5 adverse event rates and cumulative ORRs. Out of 1735 studies, 54 publications were included that involved 6372 participants and 21 cancers. Of the 54 studies in our sample, 31 (57.41%) were single-arm trials and 23 (42.60%) had negative results. Trials among and within various indications had conflicting results over time. Cumulative risk to participants increased over time, and clinical benefit decreased. The findings suggest that the risk profile of cabozantinib increased from 2011 to 2016 and has remained elevated but stable while benefit has decreased over time. The use of non-randomized and single-arm trials is concerning, and more methodologically rigorous trials are needed. The results of trials for different indications are inconsistent, and empirical administration may reduce the drug's efficacy.

IntroductionThis study determined the safety and recommended phase 2 dose (RP2D) of the multikinase inhibitor cabozantinib in combination with trifluridine/tipiracil (FTD/TPI) in refractory metastatic colorectal carcinoma (mCRC).Patients and methodsSingle institution investigator-initiated phase 1 study using 3+3 design. Eligible mCRC patients had received prior standard regimens. Cabozantinib was given orally (p.o.) at 20 mg (dose level [DL] 0) or 40 mg (DL 1) daily on days 1-28, and FTD/TPI p.o. at 35 mg/m2 on days 1-5 and 8-12 every 28 days. Prophylactic growth-factor support was allowed.ResultsFifteen patients were enrolled. Median age 56 years (31-80), male (12/15), ECOG 0/1 = 9/6. Three patients were treated at DL 0 and another nine were treated at DL 1, none exhibiting a DLT. Most common any grade (G) treatment related adverse events (TRAE) were diarrhea (50%), nausea (42%), neutropenia (42%), fatigue (33%), and rash (25%). G3-4 TRAE were neutropenia (25%) and thrombocytopenia, hypokalemia, and weight loss (each 8%). No serious TRAE or G5 were reported. The RP2D was determined to be DL 1. Median PFS was 3.8 months (95% CI 1.9-6.8) and disease control rate was 86.7%.ConclusionThe combination of cabozantinib and FTD/TPI is feasible and tolerable at standard doses with the use of growth factors and showed encouraging clinical activity in refractory mCRC.ClinicaltrialsGOV: NCT04868773.

Background and aimsAberrant activation of fatty acid synthase (FASN) is a major metabolic event during the development of HCC. We evaluated the therapeutic efficacy of TVB3664, a FASN inhibitor, either alone or in combination, for HCC treatment.Approach and resultsThe therapeutic efficacy and the molecular pathways targeted by TVB3664, either alone or with tyrosine kinase inhibitors or the checkpoint inhibitor anti-programmed death ligand 1 antibody, were assessed in human HCC cell lines and multiple oncogene-driven HCC mouse models. RNA sequencing was performed to elucidate the effects of TVB3664 on global gene expression and tumor metabolism. TVB3664 significantly ameliorated the fatty liver phenotype in the aged mice and AKT-induced hepatic steatosis. TVB3664 monotherapy showed moderate efficacy in NASH-related murine HCCs, induced by loss of phosphatase and tensin homolog and MET proto-oncogene, receptor tyrosine kinase (c-MET) overexpression. TVB3664, in combination with cabozantinib, triggered tumor regression in this murine model but did not improve the responsiveness to immunotherapy. Global gene expression revealed that TVB3664 predominantly modulated metabolic processes, whereas TVB3664 synergized with cabozantinib to down-regulate multiple cancer-related pathways, especially the AKT/mammalian target of rapamycin pathway and cell proliferation genes. TVB3664 also improved the therapeutic efficacy of sorafenib and cabozantinib in the FASN-dependent c-MYC-driven HCC model. However, TVB3664 had no efficacy nor synergistic effects in FASN-independent murine HCC models.ConclusionsThis preclinical study suggests the limited efficacy of targeting FASN as monotherapy for HCC treatment. However, FASN inhibitors could be combined with other drugs for improved effectiveness. These combination therapies could be developed based on the driver oncogenes, supporting precision medicine approaches for HCC treatment.

Sitravatinib (MGCD516), a spectrum-selective receptor tyrosine kinase inhibitor targeting TAM (TYRO3, AXL, MERTK) and split kinase family receptors, has demonstrated preclinical anti-tumor activity and modulation of tumor microenvironment. This first-in-human phase 1/1b study included sitravatinib dose exploration and anti-tumor activity evaluation in selected patients with advanced solid tumors. Primary objectives included assessment of safety, pharmacokinetics and clinical activity of sitravatinib. Secondary objectives included identifying doses for further investigation and exploring molecular markers for patient selection. In phase 1, 32 patients received 10-200 mg, while phase 1b dose expansion comprised 161 patients (150 mg n = 99, 120 mg n = 62). Maximum tolerated dose was determined as 150 mg daily. Dose-limiting toxicity was reported in 4/28 evaluable phase 1 patients (three at 200 mg, one at 80 mg). In phase 1b, 120 mg was defined as the recommended dose due to tolerability. Treatment-related adverse events (TRAEs) were experienced by 174/193 patients (90.2%); grade ≥ 3 TRAEs in 103 patients (53.4%). Most common TRAEs were diarrhea, fatigue, hypertension and nausea; TRAEs led to treatment discontinuation in 26 patients (13.5%) and death in one patient. Sitravatinib was steadily absorbed and declined from plasma with a terminal elimination half-life of 42.1-51.5 h following oral administration. Overall objective response rate was 11.8% in phase 1b, 13.2% in patients with non-small cell lung cancer (NSCLC) and 4.2% in patients with NSCLC with prior checkpoint inhibitor experience. Sitravatinib demonstrated manageable safety and modest clinical activity in solid tumors. NCT02219711 (first posted August 14, 2014).

BACKGROUND: Patients with hepatocellular carcinoma (HCC) and Child-Pugh B liver cirrhosis have poor prognosis and are underrepresented in clinical trials. The CELESTIAL trial, in which cabozantinib improved overall survival (OS) and progression-free survival (PFS) versus placebo in patients with HCC and Child-Pugh A liver cirrhosis at baseline, was evaluated for outcomes in patients who had Child-Pugh B cirrhosis at Week 8. METHODS: This was a retrospective analysis of adult patients with previously treated advanced HCC. Child-Pugh B status was assessed by the investigator. Patients were randomised 2:1 to cabozantinib (60 mg once daily) or placebo. RESULTS: Fifty-one patients receiving cabozantinib and 22 receiving placebo had Child-Pugh B cirrhosis at Week 8. Safety and tolerability of cabozantinib for the Child-Pugh B subgroup were consistent with the overall population. For cabozantinib- versus placebo-treated patients, median OS from randomisation was 8.5 versus 3.8 months (HR 0.32, 95% CI 0.18-0.58), median PFS was 3.7 versus 1.9 months (HR 0.44, 95% CI 0.25-0.76), and best response was stable disease in 57% versus 23% of patients. CONCLUSIONS: These encouraging results with cabozantinib support the initiation of prospective studies in patients with advanced HCC and Child-Pugh B liver function. CLINICAL TRIAL REGISTRATION: NCT01908426.

BackgroundAlbumin-bilirubin (ALBI) grade is an objective measure of liver function for patients with hepatocellular carcinoma (HCC). The tyrosine kinase inhibitor cabozantinib is approved for patients with advanced HCC who have received prior sorafenib based on the phase 3 CELESTIAL trial (NCT01908426). Cabozantinib improved overall survival (OS) and progression-free survival (PFS) versus placebo in patients with previously treated HCC.MethodsPatients were randomised 2:1 to receive cabozantinib 60 mg or placebo orally every day. Clinical outcomes in patients with ALBI grade 1 or 2 at baseline were evaluated in CELESTIAL. ALBI scores were retrospectively calculated based on baseline serum albumin and total bilirubin, with an ALBI grade of 1 defined as  ≤ -2.60 score and a grade of 2 as a score of > -2.60 to  ≤ -1.39.ResultsCabozantinib improved OS and PFS versus placebo in both ALBI grade 1 (hazard ratio [HR] [95% CI]: 0.63 [0.46-0.86] and 0.42 [0.32-0.56]) and ALBI grade 2 (HR [95% CI]: 0.84 [0.66-1.06] and 0.46 [0.37-0.58]) subgroups. Adverse events were consistent with those in the overall population. Rates of grade 3/4 adverse events associated with hepatic decompensation were generally low and were more common among patients in the ALBI grade 2 subgroup.DiscussionThese results provide initial support of cabozantinib in patients with advanced HCC irrespective of ALBI grade 1 or 2.Trial registration numberClinicalTrials.gov number, NCT01908426.

PurposeSoft-tissue sarcomas (STS) are a rare, heterogeneous group of mesenchymal tumors. For decades the mainstay of treatment for advanced, unresectable STS has been palliative chemotherapy. High levels of activated MET receptor have been reported in various sarcoma cell lines, together with elevated vascular endothelial growth factor (VEGF) levels in patients with STS, suggesting that dual targeting of the VEGF and MET pathways with the multi-receptor tyrosine kinase inhibitor cabozantinib would result in clinical benefit in this population.Patients and methodsWe performed an open-label, multi-institution, single-arm phase II trial of single-agent cabozantinib in adult patients with advanced STS and progressive disease after at least 1 standard line of systemic therapy. Patients received 60 mg oral cabozantinib once daily in 28-day cycles, and dual primary endpoints of overall response rate and 6-month progression-free survival (PFS) were assessed. Changes in several circulating biomarkers were assessed as secondary endpoints.ResultsSix (11.1%; 95% CI, 4.2%-22.6%) of the 54 evaluable patients enrolled experienced objective responses (all partial responses). Six-month PFS was 49.3% (95% CI, 36.2%-67.3%), with a median time on study of 4 cycles (range, 1-99). The most common grade 3/4 adverse events were hypertension (7.4%) and neutropenia (16.7%). Patients' levels of circulating hepatocyte growth factor (HGF), soluble MET, and VEGF-A generally increased after a cycle of therapy, while soluble VEGFR2 levels decreased, regardless of clinical outcome.ConclusionsCabozantinib single-agent antitumor activity was observed in patients with selected STS histologic subtypes (alveolar soft-part sarcoma, undifferentiated pleomorphic sarcoma, extraskeletal myxoid chondrosarcoma, and leiomyosarcoma) highlighting the biomolecular diversity of STS.

Endothelial dysfunction is associated with vascular disease and results in disruption of endothelial barrier function and increased sensitivity to apoptosis. Currently, there are limited treatments for improving endothelial dysfunction. Activated protein C (aPC), a promising therapeutic, signals via protease-activated receptor-1 (PAR1) and mediates several cytoprotective responses, including endothelial barrier stabilization and anti-apoptotic responses. We showed that aPC-activated PAR1 signals preferentially via β-arrestin-2 (β-arr2) and dishevelled-2 (Dvl2) scaffolds rather than G proteins to promote Rac1 activation and barrier protection. However, the signaling pathways utilized by aPC/PAR1 to mediate anti-apoptotic activities are not known. aPC/PAR1 cytoprotective responses also require coreceptors; however, it is not clear how coreceptors impact different aPC/PAR1 signaling pathways to drive distinct cytoprotective responses. Here, we define a β-arr2-mediated sphingosine kinase-1 (SphK1)-sphingosine-1-phosphate receptor-1 (S1PR1)-Akt signaling axis that confers aPC/PAR1-mediated protection against cell death. Using human cultured endothelial cells, we found that endogenous PAR1 and S1PR1 coexist in caveolin-1 (Cav1)-rich microdomains and that S1PR1 coassociation with Cav1 is increased by aPC activation of PAR1. Our study further shows that aPC stimulates β-arr2-dependent SphK1 activation independent of Dvl2 and is required for transactivation of S1PR1-Akt signaling and protection against cell death. While aPC/PAR1-induced, extracellular signal-regulated kinase 1/2 (ERK1/2) activation is also dependent on β-arr2, neither SphK1 nor S1PR1 are integrated into the ERK1/2 pathway. Finally, aPC activation of PAR1-β-arr2-mediated protection against apoptosis is dependent on Cav1, the principal structural protein of endothelial caveolae. These studies reveal that different aPC/PAR1 cytoprotective responses are mediated by discrete, β-arr2-driven signaling pathways in caveolae.

ObjectiveHepatocellular carcinoma (HCC) is the most common type of primary liver cancer with limited treatment options. Cabozantinib, an orally bioavailable multikinase inhibitor is now approved by Food and Drug Administration (FDA) for HCC patients. We evaluated the therapeutic efficacy of cabozantinib, either alone or in combination, in vitro and in vivo.DesignHuman HCC cell lines and HCC mouse models were used to assess the therapeutic efficacy and targeted molecular pathways of cabozantinib, either alone or in combination with the pan-mTOR inhibitor MLN0128 or the checkpoint inhibitor anti-PD-L1 antibody.ResultsCabozantinib treatment led to stable disease in c-Met/β-catenin and Akt/c-Met mouse HCC while possessing limited efficacy on Akt/Ras and c-Myc liver tumours. Importantly, cabozantinib effectively inhibited c-MET and ERK activity, leading to decreased PKM2 and increased p21 expression in HCC cells and in c-Met/β-catenin and Akt/c-Met HCC. However, cabozantinib was ineffective in inhibiting the Akt/mTOR cascade. Intriguingly, a strong inhibition of angiogenesis by cabozantinib occurred regardless of the oncogenic drivers. However, cabozantinib had limited impact on other tumour microenvironment parameters, including tumour infiltrating T cells, and did not induce programmed death-ligand 1 (PD-L1) expression. Combining cabozantinib with MLN0128 led to tumour regression in c-Met/β-catenin mice. In contrast, combined treatment with cabozantinib and the checkpoint inhibitor anti-PD-L1 antibody did not provide any additional therapeutic benefit in the four mouse HCC models tested.Conclusionc-MET/ERK/p21/PKM2 cascade and VEGFR2-induced angiogenesis are the primary targets of cabozantinib in HCC treatment. Combination therapies with cabozantinib and mTOR inhibitors may be effective against human HCC.

Hepatocellular carcinoma (HCC) is the sixth most common primary cancer with an unsatisfactory long-term survival. Gain of function mutations of PIK3CA occur in a subset of human HCC. Alpelisib, a selective PIK3CA inhibitor, has been approved by the FDA to treat PIK3CA mutant breast cancers. In this manuscript, we evaluated the therapeutic efficacy of alpelisib, either alone or in combination, for the treatment of HCC. We tested alpelisib in mouse HCC induced by hydrodynamic injection of c-Met/PIK3CA(H1047R) (c-Met/H1047R), c-Met/PIK3CA(E545K) (c-Met/E545K), and c-Met/sgPten gene combinations. Alpelisib slowed down the growth of c-Met/H1047R and c-Met/E545K HCC but was ineffective in c-Met/sgPten HCC. Mechanistically, alpelisib inhibited p-ERK and p-AKT in c-Met/H1047R and c-Met/E545K HCC progression but did not affect the mTOR pathway or genes involved in cell proliferation. In human HCC cell lines transfected with PIK3CA(H1047R), alpelisib synergized with the mTOR inhibitor MLN0128 or the CDK4/6 inhibitor palbociclib to suppress HCC cell growth. In c-Met/H1047R mice, alpelisib/MLN0128 or alpelisib/palbociclib combination therapy caused tumor regression. Our study demonstrates that alpelisib is effective for treating PIK3CA-mutated HCC by inhibiting MAPK and AKT cascades. Furthermore, combining alpelisib with mTOR or CDK4/6 inhibitors has a synergistic efficacy against PIK3CA-mutated HCC, providing novel opportunities for precision medicine against HCC.

The androgen receptor (AR) is critical in the progression of prostate cancer (PCa). Small molecule antagonists that bind to the ligand binding domain (LBD) of the AR have been successful in treating PCa. However, the structural basis by which the AR antagonists manifest their therapeutic efficacy remains unclear, due to the lack of detailed structural information of the AR bound to the antagonists. We have performed accelerated molecular dynamics (aMD) simulations of LBDs bound to a set of ligands including a natural substrate (dihydrotestosterone), an agonist (RU59063) and three antagonists (bicalutamide, enzalutamide and apalutamide) as well as in the absence of ligand (apo). We show that the binding of AR antagonists at the substrate binding pocket alter the dynamic fluctuations of H12, thereby disrupting the structural integrity of the agonistic conformation of AR. Two antagonists, enzalutamide and apalutamide, induce considerable structural changes to the agonist conformation of LBD, when bound close to H12 of AR LBD. When the antagonists bind to the pocket with different orientations having close contact with H11, no significant conformational changes were observed, suggesting the AR remains in the functionally activated (agonistic) state. The simulations on a drug resistance mutant F876L bound to enzalutamide demonstrated that the mutation stabilizes the agonistic conformation of AR LBD, which compromises the efficacy of the antagonists. Principal component analysis (PCA) of the structural fluctuations shows that the binding of enzalutamide and apalutamide induce conformational fluctuations in the AR, which are markedly different from those caused by the agonist as well as another antagonist, bicalutamide. These fluctuations could only be observed with the use of aMD.

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

ObjectiveIn the phase 3 CELESTIAL trial, cabozantinib improved overall survival (OS) and progression-free survival (PFS) compared with placebo in patients with previously treated advanced hepatocellular carcinoma (HCC). This subgroup analysis evaluated cabozantinib in patients who had received sorafenib as the only prior systemic therapy.MethodsCELESTIAL randomised (2:1) patients with advanced HCC and Child-Pugh class A liver function to treatment with cabozantinib (60 mg daily) or placebo. Eligibility required prior treatment with sorafenib, and patients could have received ≤2 prior systemic regimens. The primary endpoint was OS. Outcomes in patients who had received sorafenib as the only prior therapy were analysed by duration of prior sorafenib (

BackgroundNo trials have compared cabozantinib and regorafenib for the second-line treatment of advanced hepatocellular carcinoma (HCC).ObjectivesConduct a matching-adjusted indirect comparison (MAIC) of the efficacy and safety of second-line cabozantinib and regorafenib in patients with advanced HCC and disease progression after prior sorafenib.MethodsThe CELESTIAL and RESORCE trials were used for indirect comparison of second-line cabozantinib and regorafenib in advanced HCC. Population-level data were available for RESORCE, individual patient data (IPD) for CELESTIAL. To align with RESORCE, the CELESTIAL population was limited to patients who received first-line sorafenib only. To minimize potential effect-modifying population differences, the CELESTIAL IPD were weighted to balance the distribution of clinically relevant baseline characteristics with those of RESORCE. Overall survival (OS) and progression-free survival (PFS) were evaluated for the matching-adjusted second-line CELESTIAL population and compared with those for RESORCE using weighted Kaplan-Meier curves and parametric modeling. Rates of grade 3/4 treatment-emergent adverse events (TEAEs) affecting > 5% of patients in any study arm were compared.ResultsIn the matching-adjusted second-line populations (CELESTIAL, effective sample size = 266; RESORCE, n = 573), median (95% confidence interval) OS was similar for cabozantinib and regorafenib (11.4 [8.9-17.0] versus 10.6 [9.1-12.1] months; p = 0.3474, log-rank test). Median PFS was longer for cabozantinib than regorafenib (5.6 [4.9-7.3] versus 3.1 [2.8-4.2] months; p = 0.0005, log-rank test). There was a trend for lower rates of some grade 3/4 TEAEs with regorafenib than with cabozantinib, which may reflect the exclusion of sorafenib-intolerant patients from RESORCE but not from CELESTIAL, a difference that the MAIC methods could not remove. Only diarrhea rates were statistically significantly lower for regorafenib (p  ≤ 0.001).ConclusionsCabozantinib may achieve similar OS and prolonged PFS compared with regorafenib in patients with progressive advanced HCC after prior sorafenib.

PurposeThe surface receptor MET is highly expressed on primary uveal melanoma; MET inhibitors demonstrated early clinical signals of efficacy in slowing uveal melanoma growth. The primary objective of our study was to compare the progression-free survival rate at 4 months (PFS4) of patients with uveal melanoma treated with cabozantinib or chemotherapy.Patients and methodsPatients with metastatic uveal melanoma and RECIST measurable disease were randomized 2:1 to receive either cabozantinib (arm 1) versus temozolomide or dacarbazine (arm 2) with restaging imaging every two cycles. Cross-over from arm 2 to cabozantinib after progression was allowed (arm 2X). Available tumor specimens were analyzed by whole-exome sequencing (WES) and results were correlated with outcome.ResultsForty-six eligible patients were accrued with 31, 15, and 9 in arms 1, 2, and 2X, respectively. Median lines of prior therapy, including hepatic embolization, were two. Rates of PFS4 in arm 1 and arm 2 were 32.3% and 26.7% (P = 0.35), respectively, with median PFS time of 60 and 59 days (P = 0.964; HR = 0.99). Median overall survival (OS) was 6.4 months and 7.3 months (P = 0.580; HR = 1.21), respectively. Grade 3-4 Common Terminology Criteria for Adverse Events were present in 61.3%, 46.7%, and 37.5% in arms 1, 2, and 2X, respectively. WES demonstrated a mean tumor mutational burden of 1.53 mutations/Mb and did not separate OS ≤ or >1 year (P = 0.14). Known mutations were identified by WES and novel mutations were nominated.ConclusionsMET/VEGFR blockade with cabozantinib demonstrated no improvement in PFS but an increase in toxicity relative to temozolomide/dacarbazine in metastatic uveal melanoma.

Background and aimsThe advent of direct-acting antiviral agents promises to change the management of hepatitis C virus infection (HCV) in patients with chronic kidney disease (CKD), a patient group in which the treatment of hepatitis C was historically challenging. We investigated the safety and efficacy of all-oral, interferon-free direct-acting antiviral agents for the treatment of hepatitis C in a 'real-world' cohort of patients with CKD.MethodsWe performed an observational single-arm multi-centre study in a large (n=198) cohort of patients with stage 1-3 CKD who underwent antiviral therapy with DAAs for the treatment of HCV. The primary end-point was sustained virologic response (serum HCV RNA

We report a case of a 60-year-old man who was a former cigar smoker with a slow-growing, large exophytic left shoulder mass (15 cm in diameter) and later found to have left axillary lymphadenopathy. Fine needle aspirate biopsy of the left shoulder mass revealed squamous cell carcinoma (SCC). However, pathology of the enlarged left axillary lymph node was reported as metastatic adenocarcinoma. The patient underwent surgical resection of the shoulder mass which comprised of SCC (>95%) and adenoid basal cell carcinoma (BCC) as a second component of the tumour. The BCC had identical histology as the metastatic carcinoma in the left axillary lymph node. Therefore, diagnosis was revised as cutaneous collision tumour with metastatic BCC. Six months later following adjuvant radiation therapy, the patient was diagnosed with metastatic BCC in the right lung. Stereotactic body radiation therapy (SBRT) and a selective hedgehog pathway inhibitor vismodegib were given with only limited efficacy. Clinical trial registration number NCT03132636.

Androgen receptor (AR) is a steroid hormone nuclear receptor which upon binding its endogenous androgenic ligands (agonists), testosterone and dihydrotestosterone (DHT), alters gene transcription, producing a diverse range of biological effects. Antiandrogens, such as the pharmaceuticals bicalutamide and hydroxyflutamide, act as agonists in the absence of androgens and as antagonists in their presence or in high concentration. The atomic level mechanism of action by agonists and antagonists of AR is less well characterized. Therefore, in this study, multiple 1 μs molecular dynamics (MD), docking simulations, and perturbation-response analyses were performed to more fully explore the nature of interaction between agonist or antagonist and AR and the conformational changes induced in the AR upon interaction with different ligands. We characterized the mechanism of the ligand entry/exit and found that helix-12 and nearby structural motifs respond dynamically in that process. Modeling showed that the agonist and antagonist/agonist form a hydrogen bond with Thr877/Asn705 and that this interaction is absent for antagonists. Agonist binding to AR increases the mobility of residues at allosteric sites and coactivator binding sites, while antagonist binding decreases mobility at these important sites. A new site was also identified as a potential surface for allosteric binding. These results shed light on the effect of agonists and antagonists on the structure and dynamics of AR.

Hepatocellular carcinoma (HCC) has emerged as a major cause of cancer deaths globally. The landscape of systemic therapy has recently changed, with six additional systemic agents either approved or awaiting approval for advanced stage HCC. While these agents have the potential to improve outcomes, a survival increase of 2-5 months remains poor and falls short of what has been achieved in many other solid tumor types. The roles of genomics, underlying cirrhosis, and optimal use of treatment strategies that include radiation, liver transplantation, and surgery remain unanswered. Here, we discuss new treatment opportunities, controversies, and future directions in managing HCC.

Background & aimsA comprehensive analysis of changes in symptoms and functioning during and after direct-acting antiviral (DAA) therapy for chronic hepatitis C virus (HCV) infection has not been conducted for patients treated in real-world clinical settings. Therefore, we evaluated patient-reported outcomes (PROs) in a diverse cohort of patients with HCV treated with commonly prescribed DAAs.MethodsPROP UP is a US multicenter observational study of 1,601 patients with HCV treated with DAAs in 2016-2017. PRO data were collected at baseline (T1), early on-treatment (T2), late on-treatment (T3) and 3-months post-treatment (T4). PRO mean change scores were calculated from baseline and a minimally important change (MIC) threshold was set at 5%. Regression analyses investigated patient and treatment characteristics independently associated with PRO changes on-treatment and post-treatment.ResultsOf 1,564 patients, 55% were male, 39% non-white, 47% had cirrhosis. Sofosbuvir/ledipasvir was prescribed to 63%, sofosbuvir/velpatasvir to 21%, grazoprevir/elbasvir to 11%, and paritaprevir/ombitasvir/ritonavir + dasabuvir to 5%. During DAA therapy, mean PRO scores improved slightly in the overall cohort, but did not reach the 5% MIC threshold. Between 21-53% of patients experienced >5% improved PROs while 23-36% experienced >5% worse symptoms. Of 1,410 patients with evaluable sustained virologic response (SVR) data, 95% achieved SVR. Among those with SVR, all mean PRO scores improved, with the 5% MIC threshold met for fatigue, sleep disturbance, and functioning well-being. Regression analyses identified subgroups, defined by age 35-55, baseline mental health issues and a higher number of health comorbidities as predictors of PRO improvements.ConclusionsIn real-world clinical practices, we observed heterogeneous patient experiences during and after DAA treatment. Symptom improvements were more pronounced in younger patients, those with baseline mental health issues and multiple comorbidities.Lay summaryPatients who received direct-acting antiviral medications for hepatitis C at several liver centers in the US did not generally experience significant changes in baseline symptoms during treatment. We observed a full range of patient experiences with some patients experiencing substantial symptom improvements, yet others experiencing less improvements and some even experiencing a worsening of symptoms. The 1,346 patients who were cured of hepatitis C experienced improvements in fatigue, sleep disturbance, and functional well-being, and trends for improved pain and depression; whereas the 64 who were not cured experienced minimal improvements. Clinicaltrial.gov: NCT02601820.

Basal cell carcinomas (BCCs) rely on Hedgehog (HH) pathway growth signal amplification by the microtubule-based organelle, the primary cilium. Despite naive tumor responsiveness to Smoothened inhibitors (Smoi), resistance in advanced tumors remains common. Although the resistant BCCs usually maintain HH pathway activation, squamous cell carcinomas with Ras/MAPK pathway activation also arise, and the molecular basis of tumor type and pathway selection are still obscure. Here, we identify the primary cilium as a critical determinant controlling tumor pathway switching. Strikingly, Smoothened inhibitor-resistant BCCs have an increased mutational load in ciliome genes, resulting in reduced primary cilia and HH pathway activation compared with naive or Gorlin syndrome patient BCCs. Gene set enrichment analysis of resistant BCCs with a low HH pathway signature showed increased Ras/MAPK pathway activation. Tissue analysis confirmed an inverse relationship between primary cilia presence and Ras/MAPK activation, and primary cilia removal in BCCs potentiated Ras/MAPK pathway activation. Moreover, activating Ras in HH-responsive cell lines conferred resistance to both canonical (vismodegib) and noncanonical (atypical protein kinase C and MRTF inhibitors) HH pathway inhibitors and conferred sensitivity to MAPK inhibitors. Our results provide insights into BCC treatment and identify the primary cilium as an important lineage gatekeeper, preventing HH-to-Ras/MAPK pathway switching.

PurposeAlthough most children with medulloblastoma are cured of their disease, Sonic Hedgehog (SHH) subgroup medulloblastoma driven by TRP53 mutations is essentially lethal. Casein kinase 1α (CK1α) phosphorylates and destabilizes GLI transcription factors, thereby inhibiting the key effectors of SHH signaling. We therefore tested a second-generation CK1α activator against TRP53-mutant, MYCN-amplified medulloblastoma.Experimental designThe ability of this CK1α activator to block SHH signaling was determined in vitro using GLI reporter cells, granular precursor primary cultures, and PATCHED1 (PTCH1)-mutant sphere cultures. While in vivo efficacy was tested using 2 different medulloblastoma mouse models: PTCH1 and ND2:SMOA1. Finally, the clinical relevance of CK1α activators was demonstrated using a TRP53-mutant, MYCN-amplified patient-derived xenograft.ResultsSSTC3 inhibited SHH activity in vitro, acting downstream of the vismodegib target SMOOTHENED (SMO), and reduced the viability of sphere cultures derived from SHH medulloblastoma. SSTC3 accumulated in the brain, inhibited growth of SHH medulloblastoma tumors, and blocked metastases in a genetically engineered vismodegib-resistant mouse model of SHH medulloblastoma. Importantly, SSTC3 attenuated growth and metastasis of orthotopic patient-derived TRP53-mutant, MYCN-amplified, SHH subgroup medulloblastoma xenografts, increasing overall survival.ConclusionsUsing a newly described small-molecule, SSTC3, we show that CK1a activators could address a significant unmet clinical need for patients with SMO inhibitor-resistant medulloblastoma, including those harboring mutations in TRP53.

A major limitation of targeted cancer therapy is the rapid emergence of drug resistance, which often arises through mutations at or downstream of the drug target or through intrinsic resistance of subpopulations of tumor cells. Medulloblastoma (MB), the most common pediatric brain tumor, is no exception, and MBs that are driven by sonic hedgehog (SHH) signaling are particularly aggressive and drug-resistant. To find new drug targets and therapeutics for MB that may be less susceptible to common resistance mechanisms, we used a developmental phosphoproteomics approach in murine granule neuron precursors (GNPs), the developmental cell of origin of MB. The protein kinase CK2 emerged as a driver of hundreds of phosphorylation events during the proliferative, MB-like stage of GNP growth, including the phosphorylation of three of the eight proteins commonly amplified in MB. CK2 was critical to the stabilization and activity of the transcription factor GLI2, a late downstream effector in SHH signaling. CK2 inhibitors decreased the viability of primary SHH-type MB patient cells in culture and blocked the growth of murine MB tumors that were resistant to currently available Hh inhibitors, thereby extending the survival of tumor-bearing mice. Because of structural interactions, one CK2 inhibitor (CX-4945) inhibited both wild-type and mutant CK2, indicating that this drug may avoid at least one common mode of acquired resistance. These findings suggest that CK2 inhibitors may be effective for treating patients with MB and show how phosphoproteomics may be used to gain insight into developmental biology and pathology.

BackgroundTo overcome challenges with traditional response assessment in anti-angiogenic agents, the current study uses T1 subtraction maps to quantify volumetric radiographic response in monotherapy with cabozantinib, an orally bioavailable tyrosine kinase inhibitor with activity against vascular endothelial growth factor receptor 2 (VEGFR2), hepatocyte growth factor receptor (MET), and AXL, in an open-label, phase II trial in patients with recurrent glioblastoma (GBM) (NCT00704288).MethodsA total of 108 patients with adequate imaging data and confirmed recurrent GBM were included in this retrospective study from a phase II multicenter trial of cabozantinib monotherapy (XL184-201) at either 100 mg (N = 87) or 140 mg (N = 21) per day. Contrast enhanced T1-weighted digital subtraction maps were used to define volume of contrast-enhancing tumor at baseline and subsequent follow-up time points. Volumetric radiographic response (>65% reduction in contrast-enhancing tumor volume from pretreatment baseline tumor volume sustained for more than 4 wk) was tested as an independent predictor of overall survival (OS).ResultsVolumetric response rate for all therapeutic doses was 38.9% (41.4% and 28.6% for 100 mg and 140 mg doses, respectively). A log-linear association between baseline tumor volume and OS (P = 0.0006) and a linear correlation between initial change in tumor volume and OS (P = 0.0256) were observed. A significant difference in OS was observed between responders (median OS = 20.6 mo) and nonresponders (median OS = 8.0 mo) (hazard ratio [HR] = 0.3050, P < 0.0001). Multivariable analyses showed that continuous measures of baseline tumor volume (HR = 1.0233, P < 0.0001) and volumetric response (HR = 0.2240, P < 0.0001) were independent predictors of OS.ConclusionsT1 subtraction maps provide value in determining response in recurrent GBM treated with cabozantinib and correlated with survival benefit.

BackgroundCabozantinib inhibits tyrosine kinases, including vascular endothelial growth factor receptors 1, 2, and 3, MET, and AXL, which are implicated in the progression of hepatocellular carcinoma and the development of resistance to sorafenib, the standard initial treatment for advanced disease. This randomized, double-blind, phase 3 trial evaluated cabozantinib as compared with placebo in previously treated patients with advanced hepatocellular carcinoma.MethodsA total of 707 patients were randomly assigned in a 2:1 ratio to receive cabozantinib (60 mg once daily) or matching placebo. Eligible patients had received previous treatment with sorafenib, had disease progression after at least one systemic treatment for hepatocellular carcinoma, and may have received up to two previous systemic regimens for advanced hepatocellular carcinoma. The primary end point was overall survival. Secondary end points were progression-free survival and the objective response rate.ResultsAt the second planned interim analysis, the trial showed significantly longer overall survival with cabozantinib than with placebo. Median overall survival was 10.2 months with cabozantinib and 8.0 months with placebo (hazard ratio for death, 0.76; 95% confidence interval [CI], 0.63 to 0.92; P=0.005). Median progression-free survival was 5.2 months with cabozantinib and 1.9 months with placebo (hazard ratio for disease progression or death, 0.44; 95% CI, 0.36 to 0.52; P

The cell adhesion glycoprotein E-cadherin (CDH1) is commonly inactivated in breast tumors. Precision medicine approaches that exploit this characteristic are not available. Using perturbation screens in breast tumor cells with CRISPR/Cas9-engineered CDH1 mutations, we identified synthetic lethality between E-cadherin deficiency and inhibition of the tyrosine kinase ROS1. Data from large-scale genetic screens in molecularly diverse breast tumor cell lines established that the E-cadherin/ROS1 synthetic lethality was not only robust in the face of considerable molecular heterogeneity but was also elicited with clinical ROS1 inhibitors, including foretinib and crizotinib. ROS1 inhibitors induced mitotic abnormalities and multinucleation in E-cadherin-defective cells, phenotypes associated with a defect in cytokinesis and aberrant p120 catenin phosphorylation and localization. In vivo, ROS1 inhibitors produced profound antitumor effects in multiple models of E-cadherin-defective breast cancer. These data therefore provide the preclinical rationale for assessing ROS1 inhibitors, such as the licensed drug crizotinib, in appropriately stratified patients.Significance: E-cadherin defects are common in breast cancer but are currently not targeted with a precision medicine approach. Our preclinical data indicate that licensed ROS1 inhibitors, including crizotinib, should be repurposed to target E-cadherin-defective breast cancers, thus providing the rationale for the assessment of these agents in molecularly stratified phase II clinical trials. Cancer Discov; 8(4); 498-515. ©2018 AACR.This article is highlighted in the In This Issue feature, p. 371.

Basal cell carcinoma (BCC) is the most common form of human cancer, with a continually increasing annual incidence in the United States. When diagnosed early, the majority of BCCs are readily treated with office-based therapy, which is highly curative. In these evidence-based guidelines of care, we provide recommendations for the management of patients with BCC, as well as an in-depth review of the best available literature in support of these recommendations. We discuss biopsy techniques for a clinically suspicious lesion and offer recommendations for the histopathologic interpretation of BCC. In the absence of a formal staging system, the best available stratification based on risk for recurrence is reviewed. With regard to treatment, we provide recommendations on treatment modalities along a broad therapeutic spectrum, ranging from topical agents and superficially destructive modalities to surgical techniques and systemic therapy. Finally, we review the available literature and provide recommendations on prevention and the most appropriate follow-up for patients in whom BCC has been diagnosed.

Basal cell carcinoma (BCC) is the most common form of human cancer, with a continually increasing annual incidence in the United States. When diagnosed early, the majority of BCCs are readily treated with office-based therapy, which is highly curative. In these evidence-based guidelines of care, we provide recommendations for the management of patients with BCC, as well as an in-depth review of the best available literature in support of these recommendations. We discuss biopsy techniques for a clinically suspicious lesion and offer recommendations for the histopathologic interpretation of BCC. In the absence of a formal staging system, the best available stratification based on risk for recurrence is reviewed. With regard to treatment, we provide recommendations on treatment modalities along a broad therapeutic spectrum, ranging from topical agents and superficially destructive modalities to surgical techniques and systemic therapy. Finally, we review the available literature and provide recommendations on prevention and the most appropriate follow-up for patients in whom BCC has been diagnosed.

BackgroundCabozantinib is a potent, multitarget inhibitor of MET and vascular endothelial growth factor receptor 2 (VEGFR2). This open-label, phase II trial evaluated cabozantinib in patients with recurrent or progressive glioblastoma (GBM).MethodsPatients were initially enrolled to a starting cabozantinib dose of 140 mg/day, but the starting dose was amended to 100 mg/day because of safety concerns. Treatment continued until disease progression or unacceptable toxicity. The primary endpoint was objective response rate, assessed by an independent radiology facility using modified Response Assessment in Neuro-Oncology criteria. Additional endpoints included duration of response, 6-month and median progression-free survival, overall survival, glucocorticoid use, and safety.ResultsAmong 222 patients enrolled, 70 had received prior antiangiogenic therapy. Herein, we report results in this subset of 70 patients. The objective response rate was 4.3%, and the median duration of response was 4.2 months. The proportion of patients alive and progression free at 6 months was 8.5%. Median progression-free survival was 2.3 months, and median overall survival was 4.6 months. The most common adverse events reported in all patients, regardless of dose group, included fatigue (74.3%), diarrhea (47.1%), increased alanine aminotransferase (37.1%), headache (35.7%), hypertension (35.7%), and nausea (35.7%); overall, 34 (48.6%) patients experienced adverse events that resulted in dose reductions.ConclusionsCabozantinib treatment appeared to have modest clinical activity with a 4.3% response rate in patients who had received prior antiangiogenic therapy for GBM.Clinical trials registration numberNCT00704288 (https://www.clinicaltrials.gov/ct2/show/NCT00704288).

BackgroundCabozantinib is a tyrosine kinase inhibitor with activity against vascular endothelial growth factor receptor 2 (VEGFR2) and MET that has demonstrated clinical activity in advanced solid tumors. This open-label, phase II trial evaluated cabozantinib in patients with recurrent or refractory glioblastoma (GBM).MethodsPatients were initially enrolled at a starting dose of 140 mg/day, but the starting dose was amended to 100 mg/day because of toxicity. Treatment continued until disease progression or unacceptable toxicity. The primary endpoint was objective response rate assessed by an independent radiology facility using modified Response Assessment in Neuro-Oncology criteria. Additional endpoints included duration of response, 6-month and median progression-free survival, overall survival, and safety.ResultsAmong 152 patients naive to prior antiangiogenic therapy, the objective response rate was 17.6% and 14.5% in the 140 mg/day and 100 mg/day groups, respectively, which did not meet the predefined statistical target for success. The proportions of patients alive and progression free at 6 months were 22.3% and 27.8%, respectively. Median progression-free survival was 3.7 months in both groups, and median overall survival was 7.7 months and 10.4 months, respectively. The incidence of grade 3/4 adverse events (AEs) was 79.4% and 84.7% in the 140 mg/day and 100 mg/day groups, respectively, and dose reductions due to AEs were experienced by 61.8% and 72.0%, respectively. Common grade 3/4 AEs included fatigue, diarrhea, and palmar-plantar erythrodysesthesia syndrome.ConclusionsCabozantinib showed evidence of clinical activity in patients with recurrent GBM naive to antiangiogenic therapy, although the predefined statistical target for success was not met. At the starting doses assessed, AEs were frequently managed with dose reductions.Clinical trials registration numberNCT00704288 (https://www.clinicaltrials.gov/ct2/show/NCT00704288).

The antiandrogen bicalutamide is widely used in the treatment of advanced prostate cancer (PCa) in many countries, but its effect on castration-resistant PCa (CRPC) is limited. We previously showed that resistance to bicalutamide results from activation of mechanistic target of rapamycin (mTOR). Interestingly, clinical trials testing combinations of the mTOR inhibitor RAD001 with bicalutamide were effective in bicalutamide-naïve CRPC patients, but not in bicalutamide-pretreated ones. Here we investigate causes for their difference in response. Evaluation of CRPC cell lines identified resistant vs sensitive in vitro models, and revealed that increased eIF4E(S209) phosphorylation is associated with resistance to the combination. We confirmed using a human-derived tumor xenograft mouse model that bicalutamide pre-treatment is associated with an increase in eIF4E(S209) phosphorylation. Thus, AR suppressed eukaryotic initiation factor 4E (eIF4E) phosphorylation, while the use of antiandrogens relieved this suppression, thereby triggering its increase. Additional investigation in human prostatectomy samples showed that increased eIF4E phosphorylation strongly correlated with the cell proliferation marker Ki67. Small interfering RNA-mediated knockdown (k/d) of eIF4E-sensitized CRPC cells to RAD001+bicalutamide, whereas eIF4E overexpression induced resistance. Inhibition of eIF4E phosphorylation by treatment with CGP57380 (an inhibitor of mitogen-activated protein kinase-interacting serine-threonine kinases MAP kinase-interacting kinase 1 (Mnk1/2), the eIF4E upstream kinase) or inhibitors of extracellular signal-regulated kinase 1/2 (ERK1/2), the upstream kinase-regulating Mnk1/2, also sensitized CRPC cells to RAD001+bicalutamide. Examination of downstream targets of eIF4E-mediated translation, including survivin, demonstrated that eIF4E(S209) phosphorylation increased cap-independent translation, whereas its inhibition restored cap-dependent translation, which could be inhibited by mTOR inhibitors. Thus, our results demonstrate that while combinations of AR and mTOR inhibitors were effective in suppressing tumor growth by inhibiting both AR-induced transcription and mTOR-induced cap-dependent translation, pre-treatment with AR antagonists including bicalutamide increased eIF4E phosphorylation that induced resistance to combinations of AR and mTOR inhibitors by inducing cap-independent translation. We conclude that this resistance can be overcome by inhibiting eIF4E phosphorylation with Mnk1/2 or ERK1/2 inhibitors.

The SMOOTHENED inhibitor vismodegib is FDA approved for advanced basal cell carcinoma (BCC), and shows promise in clinical trials for SONIC HEDGEHOG (SHH)-subgroup medulloblastoma (MB) patients. Clinical experience with BCC patients shows that continuous exposure to vismodegib is necessary to prevent tumor recurrence, suggesting the existence of a vismodegib-resistant reservoir of tumor-propagating cells. We isolated such tumor-propagating cells from a mouse model of SHH-subgroup MB and grew them as sphere cultures. These cultures were enriched for the MB progenitor marker SOX2 and formed tumors in vivo. Moreover, while their ability to self-renew was resistant to SHH inhibitors, as has been previously suggested, this self-renewal was instead WNT-dependent. We show here that loss of Trp53 activates canonical WNT signaling in these SOX2-enriched cultures. Importantly, a small molecule WNT inhibitor was able to reduce the propagation and growth of SHH-subgroup MB in vivo, in an on-target manner, leading to increased survival. Our results imply that the tumor-propagating cells driving the growth of bulk SHH-dependent MB are themselves WNT dependent. Further, our data suggest combination therapy with WNT and SHH inhibitors as a therapeutic strategy in patients with SHH-subgroup MB, in order to decrease the tumor recurrence commonly observed in patients treated with vismodegib.

BackgroundPrimary analysis of the double-blind, phase III Efficacy of XL184 (Cabozantinib) in Advanced Medullary Thyroid Cancer (EXAM) trial demonstrated significant improvement in progression-free survival with cabozantinib versus placebo in patients with progressive medullary thyroid cancer (MTC). Final analysis of overall survival (OS), a key secondary endpoint, was carried out after long-term follow-up.Patients and methodsEXAM compared cabozantinib with placebo in 330 patients with documented radiographic progression of metastatic MTC. Patients were randomized (2:1) to cabozantinib (140 mg/day) or placebo. Final OS and updated safety data are reported.ResultsMinimum follow-up was 42 months. Kaplan-Meier analysis showed a 5.5-month increase in median OS with cabozantinib versus placebo (26.6 versus 21.1 months) although the difference did not reach statistical significance [stratified hazard ratio (HR), 0.85; 95% confidence interval (CI), 0.64-1.12; P = 0.24]. In an exploratory assessment of OS, progression-free survival, and objective response rate, cabozantinib appeared to have a larger treatment effect in patients with RET M918T mutation-positive tumors compared with patients not harboring this mutation. For patients with RET M918T-positive disease, median OS was 44.3 months for cabozantinib versus 18.9 months for placebo [HR, 0.60; 95% CI, 0.38-0.94; P = 0.03 (not adjusted for multiple subgroup analyses)], with corresponding values of 20.2 versus 21.5 months (HR, 1.12; 95% CI, 0.70-1.82; P = 0.63) in the RET M918T-negative subgroup. Median treatment duration was 10.8 months with cabozantinib and 3.4 months with placebo. The safety profile for cabozantinib remained consistent with that of the primary analysis.ConclusionThe secondary end point was not met in this final OS analysis from the trial of cabozantinib in patients with metastatic, radiographically progressive MTC. A statistically nonsignificant increase in OS was observed for cabozantinib compared with placebo. Exploratory analyses suggest that patients with RET M918T-positive tumors may experience a greater treatment benefit with cabozantinib.Trial registration numberNCT00704730.

Cabozantinib is an inhibitor of tyrosine kinases, including MET, vascular endothelial growth factor receptor, AXL and RET. This multi-cohort phase II randomised discontinuation trial explored anticancer activity of cabozantinib in nine tumour types.Cabozantinib was administered (100 mg, once daily) to patients with advanced, recurrent or metastatic cancers. Those with stable disease at week 12 were randomised 1:1 to cabozantinib or placebo. Primary end-points were objective response rate (ORR) at week 12 and progression-free survival (PFS) in the randomised phase.A total of 526 patients were enrolled. The highest ORR was observed in ovarian cancer (OC) (21.7%); the largest PFS benefit was observed in castration-resistant prostate cancer (CRPC) (median 5.5 versus 1.4 months for placebo; hazard ratio 0.14, 95% confidence interval: 0.04, 0.52). Disease control rates were >40% for CRPC, OC, melanoma, metastatic breast cancer (MBC), hepatocellular carcinoma (HCC) and non-small cell lung cancer. Median duration of response ranged from 3.3 (MBC) to 11.2 months (OC). Encouraging efficacy results and symptomatic improvements prompted early suspension of the randomised stage and conversion to open-label non-randomised expansion cohorts. Dose reductions to manage adverse events (AEs) occurred in 48.7% of patients. The most frequent grade III-IV AEs were fatigue (12.4%), diarrhoea (10.5%), hypertension (10.5%) and palmar-plantar erythrodysesthesia syndrome (8.7%).Clinical antitumour activity of cabozantinib was observed in a subset of tumour types: CRPC and OC were evaluated further in expansion cohorts. Phase III programs were initiated in CRPC and HCC. Interpretation of efficacy outcomes was limited by early termination of the randomised portion of the trial.NCT00940225.

Purpose: Anti-VEGF therapies remain controversial in the treatment of recurrent glioblastoma (GBM). In the current study, we demonstrate that recurrent GBM patients with a specific diffusion MR imaging signature have an overall survival (OS) advantage when treated with cediranib, bevacizumab, cabozantinib, or aflibercept monotherapy at first or second recurrence. These findings were validated using a separate trial comparing bevacizumab with lomustine.Experimental Design: Patients with recurrent GBM and diffusion MRI from the monotherapy arms of 5 separate phase II clinical trials were included: (i) cediranib (NCT00035656); (ii) bevacizumab (BRAIN Trial, AVF3708g; NCT00345163); (iii) cabozantinib (XL184-201; NCT00704288); (iv) aflibercept (VEGF Trap; NCT00369590); and (v) bevacizumab or lomustine (BELOB; NTR1929). Apparent diffusion coefficient (ADC) histogram analysis was performed prior to therapy to estimate "ADCL," the mean of the lower ADC distribution. Pretreatment ADCL, enhancing volume, and clinical variables were tested as independent prognostic factors for OS.Results: The coefficient of variance (COV) in double baseline ADCL measurements was 2.5% and did not significantly differ (P = 0.4537). An ADCL threshold of 1.24 μm2/ms produced the largest OS differences between patients (HR ∼ 0.5), and patients with an ADCL > 1.24 μm2/ms had close to double the OS in all anti-VEGF therapeutic scenarios tested. Training and validation data confirmed that baseline ADCL was an independent predictive biomarker for OS in anti-VEGF therapies, but not in lomustine, after accounting for age and baseline enhancing tumor volume.Conclusions: Pretreatment diffusion MRI is a predictive imaging biomarker for OS in patients with recurrent GBM treated with anti-VEGF monotherapy at first or second relapse. Clin Cancer Res; 23(19); 5745-56. ©2017 AACR.

Perturbation of the gut-associated microbial community may underlie many human illnesses, but the mechanisms that maintain homeostasis are poorly understood. We found that the depletion of butyrate-producing microbes by antibiotic treatment reduced epithelial signaling through the intracellular butyrate sensor peroxisome proliferator-activated receptor γ (PPAR-γ). Nitrate levels increased in the colonic lumen because epithelial expression of Nos2, the gene encoding inducible nitric oxide synthase, was elevated in the absence of PPAR-γ signaling. Microbiota-induced PPAR-γ signaling also limits the luminal bioavailability of oxygen by driving the energy metabolism of colonic epithelial cells (colonocytes) toward β-oxidation. Therefore, microbiota-activated PPAR-γ signaling is a homeostatic pathway that prevents a dysbiotic expansion of potentially pathogenic Escherichia and Salmonella by reducing the bioavailability of respiratory electron acceptors to Enterobacteriaceae in the lumen of the colon.

Activation of the androgen receptor (AR) and its splice variants is linked to advanced prostate cancer and drives resistance to antiandrogens. The roles of AR and AR variants in the development of resistance to androgen deprivation therapy (ADT) and bicalutamide treatment, however, are still incompletely understood. To determine whether AR variants play a role in bicalutamide resistance, we developed bicalutamide-resistant LNCaP cells (LNCaP-BicR) and found that these resistant cells express significantly increased levels of AR variants, particularly AR-V7, both at the mRNA and protein levels. Exogenous expression of AR-V7 in bicalutamide-sensitive LNCaP cells confers resistance to bicalutamide treatment. Knockdown of AR-V7 in bicalutamide- and enzalutamide-resistant CWR22Rv1, enzalutamide-resistant C4-2B (C4-2B MDVR), and LNCaP-BicR cells reversed bicalutamide resistance. Niclosamide, a potent inhibitor of AR variants, significantly enhanced bicalutamide treatment. Niclosamide and bicalutamide combination treatment not only suppressed AR and AR variants expression and inhibited their recruitment to the PSA promoter, but also significantly induced apoptosis in bicalutamide- and enzalutamide-resistant CWR22Rv1 and C4-2B MDVR cells. In addition, combination of niclosamide with bicalutamide inhibited the growth of enzalutamide-resistant tumors. In summary, our results demonstrate that AR variants, particularly AR-V7, drive bicalutamide resistance and that targeting AR-V7 with niclosamide can resensitize bicalutamide-resistant cells to bicalutamide treatment. Furthermore, combination of niclosamide with bicalutamide inhibits enzalutamide resistant tumor growth, suggesting that the combination of niclosamide and bicalutamide could be a potential cost-effective strategy to treat advanced prostate cancer in patients, including those who fail to respond to enzalutamide therapy. Mol Cancer Ther; 16(8); 1521-30. ©2017 AACR.

Background.Large cohorts are needed to assess human immunodeficiency virus (HIV)/hepatitis C virus (HCV) real-world treatment outcomes. We examined the effectiveness of ledipasvir/sofosbuvir with or without ribavirin (LDV/SOF ± RBV) and ombitasvir/ paritaprevir/ritonavir plus dasabuvir (OPrD) ± RBV in HIV/HCV genotype 1 (GT1)-coinfected patients initiating HCV therapy in clinical practice.Methods.Observational intent-to-treat cohort analysis using the Veterans Affairs Clinical Case Registry to identify HIV/HCV GT1-coinfected veterans initiating 12 weeks of LDV/SOF ± RBV or OPrD ± RBV. Multivariate models of sustained virologic response (SVR) included age, race, cirrhosis, proton pump inhibitor (PPI) prescription, prior HCV treatment, body mass index, genotype subtype, and HCV treatment regimen.Results.Nine hundred ninety-six HIV/HCV GT1-coinfected veterans initiated therapy: 757 LDV/SOF, 138 LDV/SOF + RBV, 28 OPrD, and 73 OPrD + RBV. Overall SVR was 90.9% (823/905); LDV/SOF 92.1% (631/685), LDV/SOF + RBV 86.3% (113/131), OPrD 88.9% (24/27), and OPrD + RBV 88.7% (55/62). SVR was 85.9% (176/205) and 92.4% (647/700) in those with and without cirrhosis (P = .006). SVR was similar between African Americans (90.5% [546/603]) and all others (91.7% [277/302]). PPI use with LDV/SOF ± RBV did not affect SVR (89.7% [131/146] with PPI and 91.5% [613/670] without PPI). Cirrhosis was predictive of reduced SVR (0.51 [95% confidence interval {CI}, .31-.87]; P = .01). Median creatinine change did not differ among patients receiving LDV/SOF and tenofovir disoproxil fumarate (TDF) without a protease inhibitor (PI) (0.18 [interquartile range {IQR}, 0.08-0.30]; n = 372), LDV/SOF and TDF/PI (0.17 [IQR, 0.04-0.30]; n = 100), and LDV/SOF without TDF (0.15 [IQR, 0.00-0.30]; n = 423).Conclusions.SVR rates in HIV/HCV GT1-coinfected patients were high. African American race or PPI use with LDV/SOF ± RBV was not associated with lower SVR rates, but cirrhosis was. Renal function did not worsen on LDV/SOF regimens with TDF.

PurposeCabozantinib is a multi-kinase inhibitor that targets MET, AXL, and VEGFR2, and may synergize with EGFR inhibition in NSCLC. Cabozantinib was assessed alone or in combination with erlotinib in patients with progressive NSCLC and EGFR mutations who had previously received erlotinib.MethodsThis was a phase Ib/II study (NCT00596648). The primary objectives of phase I were to assess the safety, pharmacokinetics, and pharmacodynamics and to determine maximum tolerated dose (MTD) of cabozantinib plus erlotinib in patients who failed prior erlotinib treatment. In phase II, patients with prior response or stable disease with erlotinib who progressed were randomized to single-agent cabozantinib 100 mg qd vs cabozantinib 100 mg qd and erlotinib 50 mg qd (phase I MTD), with a primary objective of estimating objective response rate (ORR).ResultsSixty-four patients were treated in phase I. Doses of 100 mg cabozantinib plus 50 mg erlotinib, or 40 mg cabozantinib plus 150 mg erlotinib were determined to be MTDs. Diarrhea was the most frequent dose-limiting toxicity and the most frequent AE (87.5% of patients). The ORR for phase I was 8.2% (90% CI 3.3-16.5). In phase II, one patient in the cabozantinib arm (N = 15) experienced a partial response, for an ORR of 6.7% (90% CI 0.3-27.9), with no responses for cabozantinib plus erlotinib (N = 13). There was no evidence that co-administration of cabozantinib markedly altered erlotinib pharmacokinetics or vice versa.ConclusionsDespite responses with cabozantinib/erlotinib in phase I, there were no responses in the combination arm of phase II in patients with acquired resistance to erlotinib. Cabozantinib did not appear to re-sensitize these patients to erlotinib.

Type I positive allosteric modulators (PAMs) of the alpha7-nicotinic receptor enhance its cholinergic activation while preserving the spatiotemporal features of synaptic transmission and the receptors characteristic rapid desensitization kinetics. Alpha7-nicotinic receptor agonists have shown promise for improving cognition in schizophrenia, but longer-term trials have been disappointing. Therefore, the type I PAM AVL-3288 was evaluated for safety and preliminary evidence of neurocognitive effect in healthy human subjects. Single-dose oral administration in ascending doses was conducted in a double-blind, placebo-controlled Phase I trial in non-smokers. The trial found indication of positive but non-significant effects on neurocognition at 10 and 30 mg, two doses that produced overlapping peak levels. There was also some evidence for effects on inhibition of the P50 auditory evoked potential to repeated stimuli, a biomarker that responds to alpha7-nicotinic receptor activation. The pharmacokinetic characteristics were consistent between subjects, and there were no safety concerns. The effects and safety profile were also assessed at 3 mg in a cohort of smokers, in whom concurrent nicotine administration did not alter either effects or safety. The trial demonstrates that a type I PAM can be safely administered to humans and that it has potential positive neurocognitive effects in central nervous system (CNS) disorders.

BackgroundCabozantinib, an orally bioavailable inhibitor of tyrosine kinases including MET, AXL, and VEGF receptors, was assessed in patients with hepatocellular carcinoma (HCC) as part of a phase 2 randomized discontinuation trial with nine tumor-type cohorts.Patients and methodsEligible patients had Child-Pugh A liver function and ≤1 prior systemic anticancer regimen, completed ≥4 weeks before study entry. The cabozantinib starting dose was 100 mg daily. After an initial 12-week cabozantinib treatment period, patients with stable disease (SD) per Response Evaluation Criteria in Solid Tumors (RECIST) version 1.0 were randomized to cabozantinib or placebo. The primary endpoint of the lead-in stage was objective response rate (ORR) at week 12, and the primary endpoint of the randomized stage was progression-free survival (PFS).ResultsAmong the 41 HCC patients enrolled, the week 12 ORR was 5%, with 2 patients achieving a confirmed partial response (PR). The week 12 disease control rate (PR or SD) was 66% (Asian subgroup: 73%). Of patients with ≥1 post-baseline scan, 78% had tumor regression, with no apparent relationship to prior sorafenib therapy. Alpha-fetoprotein (AFP) response (>50% reduction from baseline) occurred in 9 of the 26 (35%) patients with elevated baseline AFP and ≥1 post-baseline measurement. Twenty-two patients with SD at week 12 were randomized. Median PFS after randomization was 2.5 months with cabozantinib and 1.4 months with placebo, although this difference was not statistically significant. Median PFS and overall survival from Day 1 in all patients were 5.2 and 11.5 months, respectively. The most common grade 3/4 adverse events, regardless of attribution, were diarrhea (20%), hand-foot syndrome (15%), and thrombocytopenia (15%). Dose reductions were utilized in 59% of patients.ConclusionsCabozantinib has clinical activity in HCC patients, including objective tumor responses, disease stabilization, and reductions in AFP. Adverse events were managed with dose reductions.Trial registration numberNCT00940225.

BackgroundA phase II randomised discontinuation trial assessed cabozantinib (XL184), an orally bioavailable inhibitor of tyrosine kinases including VEGF receptors, MET, and AXL, in a cohort of patients with metastatic melanoma.MethodsPatients received cabozantinib 100 mg daily during a 12-week lead-in. Patients with stable disease (SD) per Response Evaluation Criteria in Solid Tumours (RECIST) at week 12 were randomised to cabozantinib or placebo. Primary endpoints were objective response rate (ORR) at week 12 and postrandomisation progression-free survival (PFS).ResultsSeventy-seven patients were enroled (62% cutaneous, 30% uveal, and 8% mucosal). At week 12, the ORR was 5%; 39% of patients had SD. During the lead-in phase, reduction in target lesions from baseline was seen in 55% of evaluable patients overall and in 59% of evaluable patients with uveal melanoma. Median PFS after randomisation was 4.1 months with cabozantinib and 2.8 months with placebo (hazard ratio of 0.59; P=0.284). Median PFS from study day 1 was 3.8 months, 6-month PFS was 33%, and median overall survival was 9.4 months. The most common grade 3/4 adverse events were fatigue (14%), hypertension (10%), and abdominal pain (8%). One treatment-related death was reported from peritonitis due to diverticular perforation.ConclusionsCabozantinib has clinical activity in patients with metastatic melanoma, including uveal melanoma. Further clinical investigation is warranted.

Background Cabozantinib and gemcitabine improve tumor control in pancreatic ductal adenocarcinoma (PDAC) in preclinical models through c-Met inhibition. We sought to determine the maximum tolerated dose (MTD) of this combination in patients with advanced PDAC. Methods Patients with ≤1 prior treatment and adequate performance status were eligible. Cabozantinib was given orally once daily, beginning day (-)7 and continued with gemcitabine given intravenously on days 1, 8, and 15 every 28 days. Dose level was assigned using Time to Event Continual Reassessment Method (TITE-CRM). Primary endpoint was MTD, defined as the highest dose level at which ≤25 % of patients incurred a dose-limiting toxicity (DLT). Secondary endpoints included response rate, progression-free survival (PFS), overall survival (OS) and urinary biomarker assessment. Results Twelve patients were enrolled and treated with 10 patients evaluable for DLT. The probability of DLT was >25 % for all dose levels tested, and thus an MTD was not determined. DLTs included grade 3 ALT/AST elevations and thrombocytopenia. Three patients had partial responses, but each discontinued therapy due to toxicity. Median PFS and OS were 4.7 (95 % CI: 1.4-9.7) and 10.1 months (95 % CI: 3.6-20.6). Exploratory biomarker analysis showed correlation of c-Met and VEGF levels with response. Conclusions An MTD for the combination was not established. Cabozantinib and gemcitabine appear impractical for further development due to DLT at low doses and continuing toxicities with ongoing therapy. Acknowledging the small sample size, responses were seen suggesting further investigation of c-Met inhibition in PDAC may be warranted.

BackgroundErlotinib is approved for the treatment of all patients with advanced non-small-cell lung cancer (NSCLC), but is most active in the treatment of EGFR mutant NSCLC. Cabozantinib, a small molecule tyrosine kinase inhibitor, targets MET, VEGFR, RET, ROS1, and AXL, which are implicated in lung cancer tumorigenesis. We compared the efficacy of cabozantinib alone or in combination with erlotinib versus erlotinib alone in patients with EGFR wild-type NSCLC.MethodsThis three group, randomised, controlled, open-label, multicentre, phase 2 trial was done in 37 academic and community oncology practices in the USA. Patients were eligible if they had received one or two previous treatments for advanced non-squamous, EGFR wild-type, NSCLC. Patients were stratified by performance status and line of therapy, and randomly assigned using permuted blocks within strata to receive open-label oral daily dosing of erlotinib (150 mg), cabozantinib (60 mg), or erlotinib (150 mg) and cabozantinib (40 mg). Imaging was done every 8 weeks. At the time of radiographic progression, there was optional crossover for patients in either single-drug group to receive combination treatment. The primary endpoint was to compare progression-free survival in patients given erlotinib alone versus cabozantinib alone, and in patients given erlotinib alone versus the combination of erlotinib plus cabozantinib. We assessed the primary endpoint in the per-protocol population, which was defined as all patients who were eligible, randomly assigned, and received at least one dose of treatment. The safety analysis population included all patients who received study treatment irrespective of eligibility. This trial is registered with ClinicalTrials.gov, number NCT01708954.FindingsBetween Feb 7, 2013, and July 1, 2014, we enrolled and randomly assigned 42 patients to erlotinib treatment, 40 patients to cabozantinib treatment, and 43 patients to erlotinib plus cabozantinib treatment, of whom 111 (89%) in total were included in the primary analysis (erlotinib [n=38], cabozantinib [n=38], erlotinib plus cabozantinib [n=35]). Compared with erlotinib alone (median 1·8 months [95% CI 1·7-2·2]), progression-free survival was significantly improved in the cabozantinib group (4·3 months [3·6-7·4]; hazard ratio [HR] 0·39, 80% CI 0·27-0·55; one-sided p=0·0003) and in the erlotinib plus cabozantinib group (4·7 months [2·4-7·4]; HR 0·37, 0·25-0·53; one-sided p=0·0003). Among participants included in the safety analysis of the erlotinib (n=40), cabozantinib (n=40), and erlotinib plus cabozantinib (n=39) groups, the most common grade 3 or 4 adverse events were diarrhoea (three [8%] cases in the erlotinib group vs three [8%] in the cabozantinib group vs 11 [28%] in the erlotinib plus cabozantinib group), hypertension (none vs ten [25%] vs one [3%]), fatigue (five [13%] vs six [15%] vs six [15%]), oral mucositis (none vs four [10%] vs one [3%]), and thromboembolic event (none vs three [8%] vs two [5%]). One death due to respiratory failure occurred in the cabozantinib group, deemed possibly related to either drug, and one death due to pneumonitis occurred in the erlotinib plus cabozantinib group, deemed related to either drug or the combination.InterpretationDespite its small sample size, this trial showed that, in patients with EGFR wild-type NSCLC, cabozantinib alone or combined with erlotinib has clinically meaningful, superior efficacy to that of erlotinib alone, with additional toxicity that was generally manageable. Cabozantinib-based regimens are promising for further investigation in this patient population.FundingECOG-ACRIN Cancer Research Group, National Cancer Institute of the National Institutes of Health.

Because many patients with unresectable basal cell carcinoma (BCC) are aged ≥65 years, this study explores the efficacy and safety of vismodegib in these patients with locally advanced (la) or metastatic (m) basal cell carcinoma (BCC) in the ERIVANCE BCC trial and the expanded access study (EAS).We compared patients aged ≥65 years to patients aged

BackgroundThe mammalian target of rapamycin (mTOR) pathway is up-regulated in castration-resistant prostate cancer (CRPC). Nevertheless, inhibition of mTOR is ineffective in inducing apoptosis in prostate cancer cells, likely because of the compensatory up-regulation of the androgen receptor (AR) pathway.MethodsPatients who were eligible for this study had to have progressive CRPC with serum testosterone levels

Nanoscale drug delivery vehicles can facilitate multimodal therapies of cancer by promoting tumour-selective drug release. However, few are effective because cancer cells develop ways to resist and evade treatment. Here, we introduce a photoactivable multi-inhibitor nanoliposome (PMIL) that imparts light-induced cytotoxicity in synchrony with a photoinitiated and sustained release of inhibitors that suppress tumour regrowth and treatment escape signalling pathways. The PMIL consists of a nanoliposome doped with a photoactivable chromophore (benzoporphyrin derivative, BPD) in the lipid bilayer, and a nanoparticle containing cabozantinib (XL184)--a multikinase inhibitor--encapsulated inside. Near-infrared tumour irradiation, following intravenous PMIL administration, triggers photodynamic damage of tumour cells and microvessels, and simultaneously initiates release of XL184 inside the tumour. A single PMIL treatment achieves prolonged tumour reduction in two mouse models and suppresses metastatic escape in an orthotopic pancreatic tumour model. The PMIL offers new prospects for cancer therapy by enabling spatiotemporal control of drug release while reducing systemic drug exposure and associated toxicities.

The seven transmembrane protein Smoothened is required for Hedgehog signaling during embryonic development and adult tissue homeostasis. Inappropriate activation of the Hedgehog signalling pathway leads to cancers such as basal cell carcinoma and medulloblastoma, and Smoothened inhibitors are now available clinically to treat these diseases. However, resistance to these inhibitors rapidly develops thereby limiting their efficacy. The determination of Smoothened crystal structures enables structure-based discovery of new ligands with new chemotypes that will be critical to combat resistance. In this study, we docked 3.2 million available, lead-like molecules against Smoothened, looking for those with high physical complementarity to its structure; this represents the first such campaign against the class Frizzled G-protein coupled receptor family. Twenty-one high-ranking compounds were selected for experimental testing, and four, representing three different chemotypes, were identified to antagonize Smoothened with IC50 values better than 50 μM. A screen for analogs revealed another six molecules, with IC50 values in the low micromolar range. Importantly, one of the most active of the new antagonists continued to be efficacious at the D473H mutant of Smoothened, which confers clinical resistance to the antagonist vismodegib in cancer treatment.