Clinical pharmacology of an atrasentan and docetaxel regimen in men with hormone-refractory prostate cancer

Pharmacogenomic Biomarkers in Docetaxel Treatment of Prostate Cancer: From Discovery to Implementation

Prostate cancer is the fifth leading cause of male cancer death worldwide. Although docetaxel chemotherapy has been used for more than fifteen years to treat metastatic castration resistant prostate cancer, the high inter-individual variability of treatment efficacy and toxicity is still not well understood. Since prostate cancer has a high heritability, inherited biomarkers of the genomic signature may be appropriate tools to guide treatment. In this review, we provide an extensive overview and discuss the current state of the art of pharmacogenomic biomarkers modulating docetaxel treatment of prostate cancer. This includes (1) research studies with a focus on germline genomic biomarkers, (2) clinical trials including a range of genetic signatures, and (3) their implementation in treatment guidelines. Based on this work, we suggest that one of the most promising approaches to improve clinical predictive capacity of pharmacogenomic biomarkers in docetaxel treatment of prostate cancer is the use of compound, multigene pharmacogenomic panels defined by specific clinical outcome measures. In conclusion, we discuss the challenges of integrating prostate cancer pharmacogenomic biomarkers into the clinic and the strategies that can be employed to allow a more comprehensive, evidence-based approach to facilitate their clinical integration. Expanding the integration of pharmacogenetic markers in prostate cancer treatment procedures will enhance precision medicine and ultimately improve patient outcomes.

Relationship Between Atrasentan Concentrations and Urinary Albumin to Creatinine Ratio in Western and Japanese Patients With Diabetic Nephropathy

PURPOSE

The objective of the current analyses was to characterize the pharmacokinetic properties of atrasentan and the exposure-response relationships for the efficacy end point, urinary albumin to creatinine ratio (UACR), and the treatment-emergent adverse event, peripheral edema, during 8 or 12 weeks of treatment.

METHODS

Results from 3 Phase II, randomized, double-blind, placebo-controlled studies (N = 257) were used for the population pharmacokinetic and exposure-response models. Concentration-time and response data for efficacy and tolerability were analyzed using a nonlinear mixed-effects population analysis and logistic regression approaches.

FINDINGS

The pharmacokinetic data were adequately described by a 2-compartment model with first-order absorption and elimination. After weight was accounted for, no clinically meaningful differences were found in CL/F or V_d/F of the central compartment between Western and Japanese patients. Exposure-response analyses confirmed the efficacy of atrasentan in reducing UACR, with an estimated decrease in UACR of ≥37% when the atrasentan dose was 0.75 mg or higher. No significant association between atrasentan exposure and the rate of edema was identified at atrasentan doses of 0.5, 0.75, and 1.25 mg. The rates of peripheral edema were comparable in patients receiving active treatment and placebo.

IMPLICATIONS

The exposure-response relationships for efficacy and tolerability were consistent between Western and Japanese patients. On the basis of these analyses, a dose of 0.75 mg/d was selected for the Phase III trial. ClinicalTrials.gov identifiers: NCT01356849, NCT01399580, and NCT01424319.

2017 update on the relationship between diabetes and colorectal cancer: epidemiology, potential molecular mechanisms and therapeutic implications

Worldwide deaths from diabetes mellitus (DM) and colorectal cancer increased by 90% and 57%, respectively, over the past 20 years. The risk of colorectal cancer was estimated to be 27% higher in patients with type 2 DM than in non-diabetic controls. However, there are potential confounders, information from lower income countries is scarce, across the globe there is no correlation between DM prevalence and colorectal cancer incidence and the association has evolved over time, suggesting the impact of additional environmental factors. The clinical relevance of these associations depends on understanding the mechanism involved. Although evidence is limited, insulin use has been associated with increased and metformin with decreased incidence of colorectal cancer. In addition, colorectal cancer shares some cellular and molecular pathways with diabetes target organ damage, exemplified by diabetic kidney disease. These include epithelial cell injury, activation of inflammation and Wnt/β-catenin pathways and iron homeostasis defects, among others. Indeed, some drugs have undergone clinical trials for both cancer and diabetic kidney disease. Genome-wide association studies have identified diabetes-associated genes (e.g. TCF7L2) that may also contribute to colorectal cancer. We review the epidemiological evidence, potential pathophysiological mechanisms and therapeutic implications of the association between DM and colorectal cancer. Further studies should clarify the worldwide association between DM and colorectal cancer, strengthen the biological plausibility of a cause-and-effect relationship through characterization of the molecular pathways involved, search for specific molecular signatures of colorectal cancer under diabetic conditions, and eventually explore DM-specific strategies to prevent or treat colorectal cancer.

Integrative meta-analysis identifies microRNA-regulated networks in infantile hemangioma

BACKGROUND

Hemangioma is a common benign tumor in the childhood; however our knowledge about the molecular mechanisms of hemangioma development and progression are still limited. Currently, microRNAs (miRNAs) have been shown as gene expression regulators with an important role in disease pathogenesis. Our goals were to identify miRNA-mRNA expression networks associated with infantile hemangioma.

METHODS

We performed a meta-analysis of previously published gene expression datasets including 98 hemangioma samples. Deregulated genes were further used to identify microRNAs as potential regulators of gene expression in infantile hemangioma. Data were integrated using bioinformatics methods, and genes were mapped in proteins, which were then used to construct protein-protein interaction networks.

RESULTS

Deregulated genes play roles in cell growth and differentiation, cell signaling, angiogenesis and vasculogenesis. Regulatory networks identified included microRNAs miR-9, miR-939 and let-7 family; these microRNAs showed the most number of interactions with deregulated genes in infantile hemangioma, suggesting that they may have an important role in the molecular mechanisms of disease. Additionally, results were used to identify drug-gene interactions and druggable gene categories using Drug-Gene Interaction Database. We show that microRNAs and microRNA-target genes may be useful biomarkers for the development of novel therapeutic strategies for patients with infantile hemangioma.

CONCLUSIONS

microRNA-regulated pathways may play a role in infantile hemangioma development and progression and may be potentially useful for future development of novel therapeutic strategies for patients with infantile hemangioma.