The use of existing medications for diseases they were not originally developed for is called drug repositioning. A popular drug repositioning method to find new drugs against specific cancer types... Show moreThe use of existing medications for diseases they were not originally developed for is called drug repositioning. A popular drug repositioning method to find new drugs against specific cancer types is to search for drugs which are expected to bring back the gene expression activity of cancer cells to that of healthy cells (‘normalization’). One of the main research goals of this thesis was to investigate of this method could also be used on the gene expression profiles of individual tumors, enabling personalization of drug repositioning candidates for each patient. We initially had some success with this approach but this eventually lead to a systematic validation of the underlying principle using almost 10,000 tumor samples across 18 different tumor types. Unfortunately, the predictive power of the method was found to be much lower than previously reported and the part that remained could be nullified by correcting the gene expression profiles of the drugs for the downstream effects of reduced cell division. These results indicate that the current use of the method does not result in drug repositioning candidates specific for a tumor type but is only able to select generally cell-toxic drugs. Show less
Within the field of pain but especially neuropathic pain there is still much to be gained, as illustrated by the unmet medical need and limitedly efficacious drug treatments currently available. A... Show moreWithin the field of pain but especially neuropathic pain there is still much to be gained, as illustrated by the unmet medical need and limitedly efficacious drug treatments currently available. A key contributor to chronification of neuropathic pain is central sensitization, which may manifest clinically as hyperalgesia, a symptom non-existent in healthy individuals. Models that can induce hyperalgesia and tools that can appropriately assess altered nociceptive functioning in early-phase drug studies are sought-after, as they may aid in examining the potential of drugs as (neuropathic) pain treatment. Continuing efforts are made to expand and improve our knowledge in this field. This thesis describes our contribution, and was based on two main objectives. One was to develop and validate methods for early-phase clinical drug studies with improved accuracy or resemblance to clinical pathophysiology, to improve the evaluation of a drug’s mechanism of action and analgesic potential. The other objective was to actually test novel drugs that are proposed to have superior clinical utility, using methods we believed to be appropriate for evaluating those drugs’ analgesic effects. Show less
This thesis describes six clinical studies: two studies that investigate new compounds to treat symptoms of multiple sclerosis (MS) (chapters 2 and 3), one study that investigates a new... Show moreThis thesis describes six clinical studies: two studies that investigate new compounds to treat symptoms of multiple sclerosis (MS) (chapters 2 and 3), one study that investigates a new compound to treat MS (chapter 4) and three studies about the development of new methods to determine effects of a new class of compounds to treat MS (chapters 5, 6 and 7). Show less
Antibiotic resistance is an increasing problem in the battle against (bacterial) infectious diseases. The emergence of drug-resistant Mycobacterium tuberculosis (Mtb) threatens to render... Show moreAntibiotic resistance is an increasing problem in the battle against (bacterial) infectious diseases. The emergence of drug-resistant Mycobacterium tuberculosis (Mtb) threatens to render tuberculosis (TB) untreatable. Efforts to develop novel antibiotics have so far been unsuccessful, calling for additional approaches for treatment of bacterial infections. Intracellular pathogens like Mtb and Salmonella can survive in the host by manipulating host cell signaling. This provides opportunities for novel therapeutic strategies by targeting the host, rather than the bacterium (host-directed therapy). In this thesis we report the development and application of novel (in vitro and in vivo) methods for identifying host genes and proteins involved in host control of intracellular bacteria, as well as chemical compounds that target host molecules as a basis for drug development for host-directed therapies. As a result, we report the identification of RTK inhibitors, the novel kinase inhibitor 97i, the human kinase family PCTAIRE and the host protein DRAM1 as promising leads for further drug development for host-directed therapeutic strategies for intracellular bacterial infections. Show less
Drug development scientists are on a search for suitable biomarkers that can assist in predicting the therapeutic potential of analgesic medication and, therefore, it’s efficacy in the target... Show moreDrug development scientists are on a search for suitable biomarkers that can assist in predicting the therapeutic potential of analgesic medication and, therefore, it’s efficacy in the target population. This is particularly appropriate for human pain where models can assist to bridge the preclinical and clinical findings. These models can provide valuable information about the mechanism of action of existing and new drugs. However, a single human pain model cannot be used exclusively to screen the pharmacological mechanism of a compound as it inherently only tests a single mechanism. In this thesis the performance of a battery of pain models (PainCart) was investigated. Three main topics were investigated. (1) The validation of the PainCart was described in which the effects of different classes of analgesics on this battery of pain models were explored. (2) The PainCart was used in different chronic pain populations. (3) The performance of the battery during the development of new analgesic compounds was studied. The battery of pain models can act as biomarker to assess the effect of analgesics on pain. It can be used to benchmark analgesic properties of new drugs against established analgesics in early phase clinical studies. Show less
This thesis describes several state-of-the-art challenge methods to study the cholinergic system in humans by measuring the effects of compounds that selectively act upon muscarinic or... Show moreThis thesis describes several state-of-the-art challenge methods to study the cholinergic system in humans by measuring the effects of compounds that selectively act upon muscarinic or nicotinic acetylcholine receptors. The thesis reveals part of the complexity of the cholinergic system, its changes related to aging, its relationship with cognitive function and performance, and its role in inflammation. Additionally, the methodology described in the thesis provides controlled circumstances using repeated measurement of drug concentrations and effects during a pharmacologic cholinergic challenge that can be used in drug development of new compounds with cholinergic activity. Show less
