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
The current symptomatic treatment for cognitive dysfunction due to dementia (eg Alzheimer's disease) is moderately effective and causes dose limiting side effects. This thesis describes the phase 1... Show moreThe current symptomatic treatment for cognitive dysfunction due to dementia (eg Alzheimer's disease) is moderately effective and causes dose limiting side effects. This thesis describes the phase 1 development of new symptomatic treatments; Gln-1062 (pro-drug of galantamine) and HTL0009936 and HTL0018318 (both M1 muscarinic receptor partial agonists). Additionally, a new methodology was investigated, which can be applied when demonstrating pharmacological effects (biperiden challenge model), and a review of all biomarkers that were used to measure cholinergic effects is presented. Show less
This thesis describes several aspects of diagnostic and therapeutic possibilities of mitochondrial function in clinical pharmacological. During several clinical studies in healthy volunteers, pre... Show moreThis thesis describes several aspects of diagnostic and therapeutic possibilities of mitochondrial function in clinical pharmacological. During several clinical studies in healthy volunteers, pre-frail elderly and Huntington’s disease patients, we used phosphorous magnetic resonance spectroscopy as the main method to measure mitochondrial function in vivo. Other in vivo methods included Near Infrared Spectroscopy and the novel Protoporphorin-9 Triplet State Lifetime Technique, besides in vitro ELISA methods to measure activity of separate complexes of the mitochondrial electron transport chain. Using these modalities, we showed mitochondrial dysfunction in pre-frail elderly, emphasizing the importance of an active lifestyle in the prevention of sarcopenia and frailty. Using the mitotoxicity of simvastatin, and its reversibility by ubiquinol, we validated the first proof-of-pharmacology model in healthy volunteers to evaluate efficacy of novel mitochondrial function improving compounds. We also described the importance of measuring (mitochondrial) oxygen consumption as a means to measure mitotoxicity of commonly described medications. Lastly, we evaluated the safety and efficacy of the novel compound SBT-020 in a placebo-controlled, double-blinded, randomized controlled trial in mild to moderate Huntington’s disease patients and compared central to peripheral mitochondrial function for the first time, gaining inside into therapeutic possibilities in this complex and devastating disease. Show less
The thesis describes the use of extensive pharmacodynamic effect profiling to characterise the clinical pharmacology of classic and non-classical analgesia. Analgesic drugs that modulate widespread... Show moreThe thesis describes the use of extensive pharmacodynamic effect profiling to characterise the clinical pharmacology of classic and non-classical analgesia. Analgesic drugs that modulate widespread targets in the nervous system can be expected to affect numerous CNS functions, which requires multimodal characterisation of pain processing and neurocognition. This is illustrated on the basis of two case studies of pharmacological agents that target cannabinoid CB1 and GABA-ergic GABAA receptors: two of the most widely distributed systems of receptors and neurotransmitters that are involved in a myriad of physiological functions. The distribution of receptors throughout the central nervous system render an oral formulation of ∆9-THC and a positive allosteric modulator of α2/3/5 subunit-containing GABAA receptors, ideal candidates for extensive neurophysiological and analgesic effect profiling in early phase clinical research. Profiling human pharmacology with a strong focus on pharmacodynamics may help to better understand the therapeutic potential and safety limitations of a compound before selection of doses and patient populations for phase II proof-of-concept studies. Show less
Some athletes use prohibited substances, a relevant problem given the coverage on doping in the media. In addition not all these athletes are being caught and clean athletes are sometimes falsely... Show moreSome athletes use prohibited substances, a relevant problem given the coverage on doping in the media. In addition not all these athletes are being caught and clean athletes are sometimes falsely accused. In short, doping is a problem in sports and society. The goal of this thesis is to contribute to a solution to this problem by applying knowledge of (clinical) pharmacology to handling the use and detection of doping. First, our research shows that there is no convincing evidence for performance enhancement for 18 out of 23 substance classes on the Prohibit List. This is problematic and is mainly due to a lack of knowledge. For this reason we evaluated one of the substances, erythropoietin (EPO), in a study that could serve as a model study for evaluating potential doping substances. This study showed that although EPO did have effects, EPO-treated cyclists did not perform any better than placebo-treated cyclists in a time trial or an uphill road race. Additionally, the doping detection methods we evaluated, for EPO and salbutamol, proved to have shortcomings in detecting cheating and protecting innocent athletes. Concluding, anti-doping efforts will need to become more evidence-based to effectively tackle the doping problem. Show less
Biopharmaceuticals are among the most celebrated drugs. However, despite decades of experience, our understanding of many in vivo pharmacokinetic and adverse effects of biopharmaceuticals is... Show moreBiopharmaceuticals are among the most celebrated drugs. However, despite decades of experience, our understanding of many in vivo pharmacokinetic and adverse effects of biopharmaceuticals is still limited. These include the delay in reaching the maximum plasma concentration for an intravenously administered therapeutical protein, and the highly variable plasma concentration during elimination of monoclonal antibodies. Both observations can be explained by dynamical binding (‘stickiness’) of proteins to various (bodily) surfaces. Biopharmaceuticals also frequently contain (non-human) impurities, some of which are harmful when administered (‘dirtiness’). This toxicity often is the result of an intricate interplay of multiple cell types and effector pathways which can be difficult to simulate in the laboratory. More sophisticated test platforms are available, which can detect a number of untoward reactions that would previously not have been discovered. However, no laboratory test is fail-safe, and awareness of the possibility of adverse immunostimulation caused by biopharmaceuticals is the most important aspect for early detection and prevention of such cases in the future. 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
