Drug Repurposing in the Chemotherapy of Infectious Diseases

Repurposing is a universal mechanism for innovation, from the evolution of feathers to the invention of Velcro tape. Repurposing is particularly attractive for drug development, given that it costs more than a billion dollars and takes longer than ten years to make a new drug from scratch. The COVID-19 pandemic has triggered a large number of drug repurposing activities. At the same time, it has highlighted potential pitfalls, in particular when concessions are made to the target product profile. Here, we discuss the pros and cons of drug repurposing for infectious diseases and analyze different ways of repurposing. We distinguish between opportunistic and rational approaches, i.e., just saving time and money by screening compounds that are already approved versus repurposing based on a particular target that is common to different pathogens. The latter can be further distinguished into divergent and convergent: points of attack that are divergent share common ancestry (e.g., prokaryotic targets in the apicoplast of malaria parasites), whereas those that are convergent arise from a shared lifestyle (e.g., the susceptibility of bacteria, parasites, and tumor cells to antifolates due to their high rate of DNA synthesis). We illustrate how such different scenarios can be capitalized on by using examples of drugs that have been repurposed to, from, or within the field of anti-infective chemotherapy.

[Current situation and development trend of digital traditional Chinese medicine pharmacy]

The 21st century is a highly information-driven era, and traditional Chinese medicine(TCM) pharmacy is also moving towards digitization and informatization. New technologies such as artificial intelligence and big data with information technology as the core are being integrated into various aspects of drug research, manufacturing, evaluation, and application, promoting interaction between these stages and improving the quality and efficiency of TCM preparations. This, in turn, provides better healthcare services to the general population. The deep integration of emerging technologies such as artificial intelligence, big data, and cloud computing with the TCM pharmaceutical industry will innovate TCM pharmaceutical technology, accelerate the research and industrialization process of TCM pharmacy, provide cutting-edge technological support to the global scientific community, boost the efficiency of the TCM industry, and promote economic and social development. Drawing from recent developments in TCM pharmacy in China, this paper discussed the current research status and future trends in digital TCM pharmacy, aiming to provide a reference for future research in this field.

Comparison and summary of in silico prediction tools for CYP450-mediated drug metabolism

The cytochrome P450 (CYP450) enzyme system is responsible for the metabolism of more than two-thirds of xenobiotics. This review summarizes reports of a series of in silico tools for CYP450 enzyme-drug interaction predictions, including the prediction of sites of metabolism (SOM) of a drug and the identification of inhibitor/substrates for CYP subtypes. We also evaluated four prediction tools to identify CYP inhibitors utilizing 52 of the most frequently prescribed drugs. ADMET Predictor and CYPlebrity demonstrated the best performance. We hope that this review provides guidance for choosing appropriate enzyme prediction tools from a variety of in silico platforms to meet individual needs. Such predictions are useful for medicinal chemists to prioritize their designed compounds for further drug discovery.

[Application and development of systems biology in computer-aided drug design]

With the advances in medicine, people have deeply understood the complex pathogenesis of diseases. Revealing the mechanism of action and therapeutic effect of drugs from an overall perspective has become the top priority of drug design. However, the traditional drug design methods cannot meet the current needs. In recent years, with the rapid development of systems biology, a variety of new technologies including metabolomics, genomics, and proteomics have been used in drug research and development. As a bridge between traditional pharmaceutical theory and modern science, computer-aided drug design(CADD) can shorten the drug development cycle and improve the success rate of drug design. The application of systems biology and CADD provides a methodological basis and direction for revealing the mechanism and action of drugs from an overall perspective. This paper introduces the research and application of systems biology in CADD from different perspectives and proposes the development direction, providing reference for promoting the application.

Various types of adenomyosis and endometriosis: In search of optimal management

Currently, the mainstay for treating endometriosis/adenomyosis consists in hormonal drugs. Aside from staying within the "therapeutic window" and cutting off the hormonal support to the ectopic endometrium, none of these treatments were developed with a pre-identified target. The current lack of innovation is humbling, especially considering that among over 34,000 PubMed-indexed publications on endometriosis or adenomyosis, ∼65% of them were published in the last two decades, many of them presumably with all the benefits of omics and molecular biology. One major reason for so many doomed research and development (R&D) projects on non-hormonal drugs is the failure to understand the natural history of the ectopic endometrium. Other reasons include, but are not limited to, the number of side-effects that these non-hormonal drug candidates presented, which the developers were either unaware of or simply had ignored when pursuing a too narrowly minded development---a common cognitive trap known as invisible gorillas. Unless we have a clear global picture with a good grasp of the natural history of ectopic endometrium, 'potholes' and 'blind alleys' in drug R&D are difficult to avoid. This review shall explore some new concepts in the progression of ectopic endometrium and explain how these new perspectives offer insights for devising better therapeutic options, explain why some drug R&D projects for endometriosis/adenomyosis have failed, provide a critical analysis of some issues encountered in everyday practice, expose knowledge gaps in need of further research, and, finally, offer possible ways to circumvent hurdles and potholes and avoid cul-de-sacs in non-hormonal drug R&D.

The impact of heme oxygenase-2 on pharmacological research: A bibliometric analysis and beyond

Heme oxygenase (HO-2) is an enzyme mainly involved in the physiologic turnover of heme and intracellular gas sensing, and it is very abundant in the brain, testes, kidneys and vessels. Since 1990, when HO-2 was discovered, the scientific community has underestimated the role of this protein in health and disease, as attested by the small amount of articles published and citations received. One of the reason that have contributed to the lack of interest in HO-2 was the difficulty in upregulating or inhibiting this enzyme. However, over the last 10 years, novel HO-2 agonists and antagonists have been synthesized, and the availability of these pharmacological tools should increase the appeal of HO-2 as drug target. In particular, these agonists and antagonists could help explain some controversial aspects, such as the neuroprotective versus neurotoxic roles of HO-2 in cerebrovascular diseases. Furthermore, the discovery of HO-2 genetic variants and their involvement in Parkinson's disease, in particular in males, opens new avenues for pharmacogenetic studies in gender medicine.

The brain heme oxygenase/biliverdin reductase system as a target in drug research and development

INTRODUCTION

The heme oxygenase/biliverdin reductase (HO/BVR) system is involved in heme metabolism. The inducible isoform of HO (HO-1) and BVR both exert cytoprotective effects by enhancing cell stress response. In this context, some xenobiotics, which target HO-1, including herbal products, behave as neuroprotectants in several experimental models of neurodegeneration. Despite this, no drug having either HO-1 or BVR as a main target is currently available.

AREAS COVERED

After a description of the brain HO/BVR system, the paper analyzes the main classes of drugs acting on the nervous system, with HO as second-level target, and their neuroprotective potential. Finally, the difficulties that exist for the development of drugs acting on HO/BVR and the possible ways to overcome these hurdles are examined.

EXPERT OPINION

Although the limited clinical evidence has restricted the translational research on the HO/BVR system, mainly because of the dual nature of its by-products, there has been growing interest in the therapeutic potential of these enzymes. Scientists should boost the translational research on the HO/BVR system which could be supported by the significant evidence provided by preclinical studies.

Pediatric Clinical Trials in Mainland China Over the Past Decade (From 2009 to 2020)

In mainland China, there remains a shortage of pediatric drugs. The Chinese government has recently launched policies and incentives to encourage pediatric drug development and clinical trials. However, data on the characteristics or development trends of these trials are limited. In this review, we extracted source data from the Chinese Clinical Trials Registry and Information Transparency Platform and systematically reviewed the pediatric clinical trials conducted in mainland China from 2009 to 2020, a comprehensive process evaluation of the pediatric drug clinical trials development in the past decade, providing data support to policy makers and industry stakeholders. We included 487 pediatric clinical trials. Over the past decade, the number of pediatric trials has increased, especially since 2016. The most common therapeutic areas were infectious diseases (n = 108, 22.2%), agents for preventive purpose (n = 99, 20.3%), and neurological and psychiatric diseases (n = 71, 14.6%). The number of clinical trials involving epilepsy (39, 10.1%), asthma (33, 8.5%), and influenza (24, 6.2%) were the highest. The distribution of leading institutions is unbalanced in mainland China, with most units in East China (34.0%) and few in Southwest China (6.9%). China has made progress in improving the research and development environment of pediatric drugs and increasing pediatric trials. However, a wide gap in pediatric drug development and clinical trials quality exists between China and the developed countries. The pharmaceutical industry in China has faced grim setbacks, including study duplication, lack of innovation, poor research design, and unbalanced resource allocation. Thus, we suggest that the Chinese government should adjust their policies to improve innovation and clinical design capacity, and optimize resource allocation between regions.

Orphan Drugs, Compounded Medication and Pharmaceutical Commons

Regulatory agencies installed orphan drug regulations to stimulate research and development of new innovative treatments for life-threatening diseases with a low prevalence (rare diseases). We established a list of well-known food-related ingredients with clinical evidence for rare diseases in the open medical literature that obtained marketing authorization as an expensive “orphan drug”, protected by intellectual property (IP) rights. We show that these ingredients are part of an established practice of medicinal compounding—a form of point of care manufacturing. We argue that these ingredients should be considered as “pharmaceutical commons”, and that regulatory incentives for private companies and market protection mechanisms such as IP rights are not justified in this case.

Convolutional Neural Network and Bidirectional Long Short-Term Memory-Based Method for Predicting Drug-Disease Associations

Identifying novel indications for approved drugs can accelerate drug development and reduce research costs. Most previous studies used shallow models for prioritizing the potential drug-related diseases and failed to deeply integrate the paths between drugs and diseases which may contain additional association information. A deep-learning-based method for predicting drug-disease associations by integrating useful information is needed. We proposed a novel method based on a convolutional neural network (CNN) and bidirectional long short-term memory (BiLSTM)-CBPred-for predicting drug-related diseases. Our method deeply integrates similarities and associations between drugs and diseases, and paths among drug-disease pairs. The CNN-based framework focuses on learning the original representation of a drug-disease pair from their similarities and associations. As the drug-disease association possibility also depends on the multiple paths between them, the BiLSTM-based framework mainly learns the path representation of the drug-disease pair. In addition, considering that different paths have discriminate contributions to the association prediction, an attention mechanism at path level is constructed. Our method, CBPred, showed better performance and retrieved more real associations in the front of the results, which is more important for biologists. Case studies further confirmed that CBPred can discover potential drug-disease associations.

A patent review of arginine methyltransferase inhibitors (2010-2018)

INTRODUCTION

Protein arginine methyltransferases (PRMTs) are fundamental enzymes that specifically modify the arginine residues of versatile substrates in cells. The aberrant expression and abnormal enzymatic activity of PRMTs are associated with many human diseases, especially cancer. PRMTs are emerging as promising drug targets in both academia and industry.

AREAS COVERED

This review summarizes the updated patented inhibitors targeting PRMTs from 2010 to 2018. The authors illustrate the chemical structures, molecular mechanism of action, pharmacological activities as well as the potential clinical application including combination therapy and biomarker-guided therapy. PRMT inhibitors in clinical trials are also highlighted. The authors provide a future perspective for further development of potent and selective PRMT inhibitors.

EXPERT OPINION

Although a number of small molecule inhibitors of PRMTs with sufficient potency have been developed, the selectivity of most PRMT inhibitors remains to be improved. Hence, novel approaches such as allosteric regulation need to be further studied to identify PRMT inhibitors. So far, three PRMT inhibitors have entered clinical trials, including PRMT5 inhibitor GSK3326595 and JNJ-64619178 as well as PRMT1 inhibitor GSK3368715. PRMT inhibitors with novel mechanism of action and good drug-like properties may shed new light on drug research and development progress.