5 research outputs found

    The c-Met tyrosine kinase inhibitor JNJ-38877605 causes renal toxicity through species-specific insoluble metabolite formation

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    Purpose: The receptor tyrosine kinase c-Met plays an important role in tumorigenesis and is a novel target for anticancer treatment. This phase I, first-in-human trial, explored safety, pharmacokinetics, pharmacodynamics, and initial antitumor activity of JNJ-38877605, a potent and selective c-Met inhibitor. Experimental Design: We performed a phase I dose-escalation study according to the standard 3+3 design. Results: Even at subtherapeutic doses, mild though recurrent renal toxicity was observed in virtually all patients. Renal toxicity had not been observed in preclinical studies in rats and dogs. Additional preclinical studies pointed toward the rabbit as a suitable toxicology model, as the formation of the M10 metabolite of JNJ-38877605 specifically occurred in rabbits and humans. Additional toxicology studies in rabbits clearly demonstrated that JNJ-38877605 induced species-specific renal toxicity. Histopathological evaluation in rabbits revealed renal crystal formation with degenerative and inflammatory changes. Identification of the components of these renal crystals revealed M1/3 and M5/6 metabolites. Accordingly, it was found that humans and rabbits showed significantly increased systemic exposure to these metabolites relative to other species. These main culprit insoluble metabolites were generated by aldehyde oxidase activity. Alternative dosing schedules of JNJ-3877605 and concomitant probenecid administration in rabbits failed to prevent renal toxicity at dose levels that could be pharmacologically active. Conclusions: Combined clinical and correlative preclinical studies suggest that renal toxicity of JNJ-38877605 is caused by the formation of species-specific insoluble metabolites. These observations preclude further clinical development of JNJ-38877605

    Enzalutamide in European and North American men participating in the AFFIRM trial

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    Objective To explore any differences in efficacy and safety outcomes between European (EU) (n = 684) and North American (NA) (n = 395) patients in the AFFIRM trial (NCT00974311).Patients and Methods Phase III, double-blind, placebo-controlled, multinational AFFIRM trial in men with metastatic castration-resistant prostate cancer (mCRPC) after docetaxel. Participants were randomly assigned in a 2:1 ratio to receive oral enzalutamide 160 mg/day or placebo. The primary end point was overall survival (OS) in a post hoc analysis.Results Enzalutamide significantly improved OS compared with placebo in both EU and NA patients. The median OS in EU patients was longer than NA patients in both treatment groups. However, the relative treatment effect, expressed as hazard ratio and 95% confidence interval, was similar in both regions: 0.64 (0.50, 0.82) for EU and 0.63 (0.47, 0.83) for NA. Significant improvements in other end points further confirmed the benefit of enzalutamide over placebo in patients from both regions. The tolerability profile of enzalutamide was comparable between EU and NA patients, with fatigue and nausea the most common adverse events. Four EU patients (4/461 enzalutamide-treated, 0.87%) and one NA patient (1/263 enzalutamide-treated, 0.38%) had seizures. The difference in median OS was related in part to the timing of development of mCRPC and baseline demographics on study entry.Conclusion This post hoc exploratory analysis of the AFFIRM trial showed a consistent OS benefit for enzalutamide in men with mCRPC who had previously progressed on docetaxel in both NA- and EU-treated patients, although the median OS was higher in EU relative to NA patients. Efficacy benefits were consistent across end points, with a comparable safety profile in both regions. © 2014 The Authors. BJU International published by John Wiley & Sons Ltd on behalf of BJU International

    Consensus Statement on Circulating Biomarkers for Advanced Prostate Cancer

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    Context: In advanced prostate cancer (PC), there is increasing investigation of circulating biomarkers, including quantitation and characterization of circulating tumour cells and cell-free nucleic acids, for therapeutic monitoring and as prognostic and predictive biomarkers. However, there is a lack of consensus and standardisation regarding analyses, reporting, and integration of results into specific clinical contexts. A consensus meeting on circulating biomarkers was held to address these topics. Objective: To present a report of the consensus statement on circulating biomarkers in advanced PC. Evidence acquisition: Four important areas of controversy in the field of circulating biomarkers in PC management were identified: known clinical utility of circulating biomarkers; unmet clinical needs for circulating biomarkers in PC care; most pressing blood-based molecular assays required; and essential steps for developing circulating biomarker assays. A panel of 18 international PC experts in the field of circulating biomarkers developed the programme and consensus questions. The panel voted publicly but anonymously on 50 predefined questions developed following a modified Delphi process. Evidence synthesis: Voting was based solely on panellist opinions of the predefined topics and therefore not on a standard literature review or meta-analysis. The outcomes of the voting had varying degrees of support, as reflected in the wording of this article and in the detailed voting results provided in the Supplementary material. Conclusions: The expert voting results presented can guide the future development of circulating biomarkers for PC care. Notably, the consensus meeting highlighted the importance of reproducibility and variability studies, among other significant areas in need of trials specifically designed to address them. Patient summary: A panel of international experts met to discuss and vote on the use of different blood-based prostate cancer tests, and how they can be used to guide treatment and disease monitoring to deliver more precise and better patient car
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