ABSTRACT
Adjunction of immune response into the TNM classification system improves the prediction of colon cancer (CC) prognosis. However, immune response measurements have not been used as robust biomarkers of pathology in clinical practice until the introduction of Immunoscore (IS), a standardized assay based on automated artificial intelligence assisted digital pathology. The strong prognostic impact of the immune response, as assessed by IS, has been widely validated and IS can help to refine treatment decision making in early CC. In this study, we compared pathologist visual scoring to IS. Four pathologists evaluated tumor specimens from 50 early-stage CC patients and classified the CD3+ and CD8+ T-cell densities at the tumor site (T-score) into 2 (High/Low) categories. Individual and overall pathologist scoring of immune response (before and after training for immune response assessment) were compared to the reference IS (High/Low). Pathologists' disagreement with the reference IS was observed in almost half of the cases (48%) and training only slightly improved the accuracy of pathologists' classification. Agreement among pathologists was minimal with a Kappa of 0.34 and 0.57 before and after training, respectively. The standardized IS assay outperformed expert pathologist assessment in the clinical setting.
ABSTRACT
Hepatitis C virus (HCV) is a major global public health problem. While the current standard of care, a direct-acting antiviral (DAA) protease inhibitor taken in combination with pegylated interferon and ribavirin, represents a major advancement in recent years, an unmet medical need still exists for treatment modalities that improve upon both efficacy and tolerability. Toward those ends, much effort has continued to focus on the discovery of new DAAs, with the ultimate goal to provide interferon-free combinations. The RNA-dependent RNA polymerase enzyme NS5B represents one such DAA therapeutic target for inhibition that has attracted much interest over the past decade. Herein, we report the discovery and optimization of a novel series of inhibitors of HCV NS5B, through the use of structure-based design applied to a fragment-derived starting point. Issues of potency, pharmacokinetics, and early safety were addressed in order to provide a clinical candidate in fluoropyridone 19.
Subject(s)
Antiviral Agents/pharmacology , Enzyme Inhibitors/pharmacology , RNA-Dependent RNA Polymerase/antagonists & inhibitors , Viral Nonstructural Proteins/antagonists & inhibitors , Animals , Antiviral Agents/chemistry , Antiviral Agents/pharmacokinetics , Area Under Curve , Cell Line, Tumor , Dogs , Drug Discovery/methods , Enzyme Inhibitors/chemistry , Enzyme Inhibitors/pharmacokinetics , Hepacivirus/drug effects , Hepacivirus/enzymology , Hepacivirus/physiology , Hepatitis C/prevention & control , Hepatitis C/virology , Host-Pathogen Interactions/genetics , Humans , Models, Molecular , Molecular Targeted Therapy/methods , Protein Binding , Protein Structure, Tertiary , Pyridones/chemical synthesis , Pyridones/pharmacokinetics , Pyridones/pharmacology , RNA-Dependent RNA Polymerase/chemistry , RNA-Dependent RNA Polymerase/metabolism , Rats , Structure-Activity Relationship , Viral Nonstructural Proteins/chemistry , Viral Nonstructural Proteins/metabolismABSTRACT
The use of fragments with low binding affinity for their targets as starting points has received much attention recently. Screening of fragment libraries has been the most common method to find attractive starting points. Herein, we describe a unique, alternative approach to generating fragment leads. A binding model was developed and a set of guidelines were then selected to use this model to design fragments, enabling our discovery of a novel fragment with high LE.
