scholarly journals Marine Natural Products, Multitarget Therapy and Repurposed Agents in Alzheimer’s Disease

2020 ◽  
Vol 13 (9) ◽  
pp. 242
Author(s):  
Márcia Martins ◽  
Renata Silva ◽  
Madalena M. M. Pinto ◽  
Emília Sousa

Alzheimer’s disease (AD) is a multifactorial disease characterized by the presence of amyloid plaques, neurofibrillary tangles, and nerve cell death that affects, mainly, older people. After decades of investigation, the search for an efficacious treatment for AD remains and several strategies can be and are being employed in this journey. In this review, four of the most promising strategies, alongside with its most promising agents under investigation or development are highlighted. Marine natural products (MNP) are a source of unique chemical structures with useful biological activities for AD treatment. One of the most promising compounds, a marine-derived acidic oligosaccharide (GV-971) just passed phase III clinical trials with a unique mechanism of action. Combination therapy and multitargeted-directed ligand therapy (MTDL) are also two important strategies, with several examples in clinical trials, based on the belief that the best approach for AD is a therapy capable of modulating multiple target pathways. Drug repurposing, a strategy that requires a smaller investment and is less time consuming, is emerging as a strong contender with a variety of pharmacological agents resurfacing in an attempt to identify a therapeutic candidate capable of modifying the course of this disease.

Author(s):  
Tanay Dalvi ◽  
Bhaskar Dewangan ◽  
Rudradip Das ◽  
Jyoti Rani ◽  
Suchita Dattatray Shinde ◽  
...  

: The most common reason behind dementia is Alzheimer’s disease (AD) and it is predicted to be the third lifethreatening disease apart from stroke and cancer for the geriatric population. Till now only four drugs are available in the market for symptomatic relief. The complex nature of disease pathophysiology and lack of concrete evidences of molecular targets are the major hurdles for developing new drug to treat AD. The the rate of attrition of many advanced drugs at clinical stages, makes the de novo discovery process very expensive. Alternatively, Drug Repurposing (DR) is an attractive tool to develop drugs for AD in a less tedious and economic way. Therefore, continuous efforts are being made to develop a new drug for AD by repursing old drugs through screening and data mining. For example, the survey in the drug pipeline for Phase III clinical trials (till February 2019) which has 27 candidates, and around half of the number are drugs which have already been approved for other indications. Although in the past the drug repurposing process for AD has been reviewed in the context of disease areas, molecular targets, there is no systematic review of repurposed drugs for AD from the recent drug development pipeline (2019-2020). In this manuscript, we are reviewing the clinical candidates for AD with emphasis on their development history including molecular targets and the relevance of the target for AD.


Author(s):  
B. Vellas ◽  
P. Aisen ◽  
M. Weiner ◽  
J. Touchon

We are happy to publish the CTAD 2018 abstracts in the present JPAD issue. As you can see many new interesting studies are presented in this issue of the journal: from new drug trials to biomarkers, imaging studies, as well as new clinical outcomes. More specifically, we will have several hot topics presentation on: 1. Major drug trials using bace inhibitors (verubecestat, lanabecestat, atabecestat, elenbecestat…) in the early phase of the disease (APECS early trials…). Both clinical, biomarkers (MRI, CSF, PET) and safety data will be presented. 2. New data on blood biomarkers including a keynote from R. Bateman, and presentations from Araclon and Roche biomarkers. 3. Results from phase III and IIB trials including a novel and multi-targeted oligosaccharide in patients with mild-moderate AD in China; the AMBAR (Alzheimer’s Management By Albumin Replacement) study, the TOMMORROW trial: a trial to delay the onset of MCI due to AD and qualify a genetic biomarker algorithm, the 18-month STEADFAST trial of azeliragon in participants with mild Alzheimer’s Disease; a longitudinal 148-week extension 4. Results 18 from F-AV-1451-A16: a clinicopathological study of the correspondence between flortaucipir PET imaging and post-mortem assessment of tau pathology. 5. Latest developments in anti-amyloid monoclonal antibodies including aducanumab nonnegligible, and new results and data analyses of the BAN2401 study 201 in early AD. 6. New developments with safety and efficacy of lemborexant for sleep-wake regulation in patients with irregular sleep-wake rhythm disorders and Alzheimer’s Disease dementia. 7. Advances with the ABBV-8E12, a humanized anti-tau monoclonal antibody, for the treatment of early Alzheimer’s Disease. 8. Endpoints for early Alzheimer’s Disease clinical trials: interpretation and application of the draft FDA guidance. And many others… It is important to underline that a not negligible number of abstracts concern non amyloid targets (eg: Tau-related targets but also targets outside the classical AD cascade).


Author(s):  
Zahra Hashemi ◽  
Mohammad Ali Ebrahimzadeh

Abstract: Inherited beta-thalassemia is a major disease caused by irregular production of hemoglobin through reducing beta-globin chains. It has been observed that increasing fetal hemoglobin (HbF) production improves symptoms in the patients. Therefore, an increase in the level of HbF has been an operative approach for treating patients with beta-thalassemia. This review represents compounds with biological activities and pharmacological properties that can promote the HBF level and therefore used in the β-thalassemia patients' therapy. Various natural products with different mechanisms of action can be helpful in this medication cure. Clinical trials were efficient in improving the signs of patients. Association of in vivo, and in vitro studies of HbF induction and γ-globin mRNA growth displays that in vitro experiments could be an indicator of the in vivo response. The current study shows that; (a) HbF inducers can be grouped in several classes based on their chemical structures and mechanism of actions; b) According to several clinical trials, well-known drugs such as hydroxyurea and decitabine are useful HbF inducers; (c) The cellular biosensor K562 carrying genes under the control of the human γ-globin and β-globin gene promoters were applied during the researches; d) New natural products and lead compounds were found based on various studies as HbF inducers.


2020 ◽  
Vol 17 (2) ◽  
pp. 112-125 ◽  
Author(s):  
Kelly Ceyzériat ◽  
Thomas Zilli ◽  
Philippe Millet ◽  
Giovanni B. Frisoni ◽  
Valentina Garibotto ◽  
...  

Alzheimer’s Disease (AD) is the most common neurodegenerative disease and cause of dementia. Characterized by amyloid plaques and neurofibrillary tangles of hyperphosphorylated Tau, AD pathology has been intensively studied during the last century. After a long series of failed trials of drugs targeting amyloid or Tau deposits, currently, hope lies in the positive results of one Phase III trial, highly debated, and on other ongoing trials. In parallel, some approaches target neuroinflammation, another central feature of AD. Therapeutic strategies are initially evaluated on animal models, in which the various drugs have shown effects on the target (decreasing amyloid, Tau and neuroinflammation) and sometimes on cognitive impairment. However, it is important to keep in mind that rodent models have a less complex brain than humans and that the pathology is generally not fully represented. Although they are indispensable tools in the drug discovery process, results obtained from animal models must be viewed with caution. In this review, we focus on the current status of disease-modifying therapies targeting amyloid, Tau and neuroinflammation with particular attention on the discrepancy between positive preclinical results on animal models and failures in clinical trials.


2010 ◽  
Vol 14 (8) ◽  
pp. 640-647 ◽  
Author(s):  
H. Fillit ◽  
J. Cummings ◽  
P. Neumann ◽  
T. Mclaughlin ◽  
P. Salavtore ◽  
...  

Author(s):  
◽  

Introduction: Alzheimer’s disease is a more common neurodegenerative disease, affecting 25 million people worldwide, or accounting for about 60 to 70% of all dementia cases. There is currently no exact mechanism to explain the pathophysiology of Alzheimer’s disease, however, cascading metabolic amyloid and post-translational review of tau protein are used as major hypotheses. Objective: To demonstrate in the literature new approaches in the development of Alzheimer’s disease modifiers. Methodology: For the accomplishment of this study made in the bibliographical survey of scientific literature and respect to the approached subject, in the databases PUBMED, ScienceDirect, Scielo and Scopus. Results: Alzheimer’s disease-modifying drugs are not yet available, but many patients may, however, develop phase III clinical trials and are intended to modify as pathological stages leading to the disease. As disease-modifying therapies under study, these changes also affect Aβ and tau protein and also cause inflammation and oxidative damage. The results obtained in the clinical trials performed were positive and promising and are still under study. The results show that there is still a long way to go in the development of Alzheimer’s disease modifying drugs. Conclusion: The results demonstrated that there is still a long way to go in the development of Alzheimer’s disease modifying drugs, but nevertheless levels at the research level should be continued in order to improve the pathophysiology of the disease and find an effective treatment for this disease the same.


CNS Spectrums ◽  
2007 ◽  
Vol 12 (2) ◽  
pp. 113-123 ◽  
Author(s):  
Daniel D. Christensen

ABSTRACTThe amyloid hypothesis—the leading mechanistic theory of Alzheimer's disease—states that an imbalance in production or clearance of amyloid β (Aβ) results in accumulation of Aβ and triggers a cascade of events leading to neurodegeneration and dementia. The number of persons with Alzheimer's disease is expected to triple by mid-century. If steps are not taken to delay the onset or slow the progression of Alzheimer's disease, the economic and personal tolls will be immense. Different classes of potentially disease-modifying treatments that interrupt early pathological events (ie, decreasing production or aggregation of Aβ or increasing its clearance) and potentially prevent downstream events are in phase II or III clinical studies. These include immunotherapies; secretase inhibitors; selective Aβ42-lowering agents; statins; anti-Aβ aggregation agents; peroxisome proliferator-activated receptor-gamma agonists; and others. Safety and serious adverse events have been a concern with immunotherapy and γ-secretase inhibitors, though both continue in clinical trials. Anti-amyloid disease-modifying drugs that seem promising and have reached phase III clinical trials include those that selectively target Aβ42 production (eg, tarenflurbil), enhance the activity of α-secretase (eg, statins), and block Aβ aggregation (eg, transiposate).


Author(s):  
Laia Montoliu-Gaya ◽  
Sandra Villegas

Current therapies to treat Alzheimer's disease (AD) are focused on ameliorating symptoms instead of treating the underlying causes of AD. The accumulation of amyloid β (Aβ) oligomers, whether by an increase in production or by a decrease in clearance, has been described as the seed that initiates the pathological cascade in AD. Developing therapies to target these species is a vital step in improving AD treatment. Aβ-immunotherapy, especially passive immunotherapy, is a promising approach to reduce the Aβ burden. Up to now, several monoclonal antibodies (mAbs) have been tested in clinical trials on humans, but none of them have passed Phase III. In all likelihood, these trials failed mainly because patients with mild-to-moderate AD were recruited, and thus treatment may have been too late to be effective. Therefore, many ongoing clinical trials are being conducted in patients at the prodromal stage. New structures based on antibody fragments have been engineered intending to improve efficacy and safety. This review presents the properties of this variety of developing treatments and provides a perspective on state-of-the-art of passive Aβ-immunotherapy in AD.


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