Primary endpoints in pediatric clinical trials are currently very similar to those in adult trials1, and focus on quantifying or counting hard endpoints like mortality, hospital admissions and... Show morePrimary endpoints in pediatric clinical trials are currently very similar to those in adult trials1, and focus on quantifying or counting hard endpoints like mortality, hospital admissions and length of stay. Additionally, biochemical biomarkers in serum are often measured to assess drug effects on a biochemical level. The occurrence of mortality and hospital admissions is rare thanks to the improvements in clinical care that have occurred in the last century, and adopting these as primary endpoints in clinical trials gives disproportional weight to rare events which most patients will not experience. Conversely, length of stay for many clinical conditions is short, and this duration only captures a small part of the clinical recovery trajectory that patients must undergo. This dissertation described the development, technical validation and clinical validation of a new type of clinical endpoints ('value based endpoints') and a new clinical trial paradigm (The remote clinical trial), consisting of digital endpoints and non-invasive pharmacokinetic sampling. Both have the potential to transform pediatric clinical trials and pediatric clinical care. The process towards implementation is challenging and can only proceed after a rigorous validation process. The current work provides a roadmap towards selection, validation, and implementation of digital endpoints, and describes preliminary steps taken for several candidates. The digital endpoints investigated in this work fulfill several validation criteria in a range of clinical conditions and, combined with non-invasive pharmacokinetics, may move the pediatric clinical trial completely towards the home. Show less
In this thesis, methods were developed, and antibody glycosylation was characterized in order to further the clinical application of antibody glycosylation analysis. New mass spectrometric... Show moreIn this thesis, methods were developed, and antibody glycosylation was characterized in order to further the clinical application of antibody glycosylation analysis. New mass spectrometric workflows were introduced in Chapters 2 and 8. Chapter 7 showed the differential characteristics of murine IgG glycosylation of different strains and highlighted the profound differences between humans and mice, with regard to IgG glycosylation. Chapters 4 and 8 showed the use of controlled human situations to study the regulatory mechanisms of IgG and IgA glycosylation. Finally, Chapters 3, 5 and 6, identified glycosidic differences with specified (patho)physiological conditions, which might be exploited for patient stratification in the future. Show less
Changes in both N- and O-glycosylation have been associated with many states of health and disease, providing prognostic and diagnostic information. O-glycans have been relatively little studied... Show moreChanges in both N- and O-glycosylation have been associated with many states of health and disease, providing prognostic and diagnostic information. O-glycans have been relatively little studied through lack of suitable analytical tools but the evidence is that they could be promising biomarkers. The release and analysis of O-glycans remains very challenging. The main reason for this is that there is no enzyme available for universal O-glycan release. Therefore, chemical release is the most effective method. Unfortunately all of the O-glycan release methods show a side reaction known as “peeling”. Peeling is well known problem when performing the O-glycan release and often results in poor repeatability. The aim of the work described in this thesis was to develop or improve methods for the release of O-glycans with free reducing termini with high yield and limited degradation. The development of sample preparation techniques for O-glycan release (in their nonreduced form) by hydrazinolysis are described. The use of procainamide for fluorescent labelling of glycans followed by HILIC-UHPLC-ESI-MS/MS analysis is introduced. The application of the improved protocols for O-glycan release by hydrazinolysis combined with developed procainamide labelling system followed by HILIC-UHPLC-ESI-MS/MS analysis for evaluation of O-glycosylation changes in human saliva. Show less
