Approved Therapeutics Research Articles

Categorizing the characteristics of human carcinogens: a need for specificity

The International Agency for Research on Cancer (IARC) has recently proposed employing "ten key characteristics of human carcinogens" (TKCs) to determine the potential of agents for harmful effects. The TKCs seem likely to confuse the unsatisfactory correlation from testing regimes that have ignored the differences evident when cellular changes are compared in short and long-lived species, with their very different stem cell and somatic cell phylogenies. The proposed characteristics are so broad that their use will lead to an increase in the current unacceptably high rate of false positives. It could be an informative experiment to take well-established approved therapeutics with well-known human safety profiles and test them against this new TKC paradigm. Cancers are initiated and driven by heritable and transient changes in gene expression, expand clonally, and progress via additional associated acquired mutations and epigenetic alterations that provide cells with an evolutionary advantage. The genotoxicity testing protocols currently employed and required by regulation, emphasize testing for the mutational potential of the test agent. Two-year, chronic rodent cancer bioassays are intended to test for the entire spectrum of carcinogenic transformation. The use of cytotoxic doses causing increased, sustained cell proliferation that facilitates accumulated genetic damage leads to a high false-positive rate of tumor induction. Current cancer hazard assessment protocols and weight-of-the-evidence analysis of agent-specific cancer risk align poorly with the pathogenesis of human carcinoma and so need modernization and improvement in ways suggested here.

The current landscape of nucleic acid therapeutics.

The increasing number of approved nucleic acid therapeutics demonstrates the potential to treat diseases by targeting their genetic blueprints in vivo. Conventional treatments generally induce therapeutic effects that are transient because they target proteins rather than underlying causes. In contrast, nucleic acid therapeutics can achieve long-lasting or even curative effects via gene inhibition, addition, replacement or editing. Their clinical translation, however, depends on delivery technologies that improve stability, facilitate internalization and increase target affinity. Here, we review four platform technologies that have enabled the clinical translation of nucleic acid therapeutics: antisense oligonucleotides, ligand-modified small interfering RNA conjugates, lipid nanoparticles and adeno-associated virus vectors. For each platform, we discuss the current state-of-the-art clinical approaches, explain the rationale behind its development, highlight technological aspects that facilitated clinical translation and provide an example of a clinically relevant genetic drug. In addition, we discuss how these technologies enable the development of cutting-edge genetic drugs, such as tissue-specific nucleic acid bioconjugates, messenger RNA and gene-editing therapeutics.

A recombinant Cedar virus based high-throughput screening assay for henipavirus antiviral discovery

Nipah virus (NiV) and Hendra virus (HeV) are highly pathogenic, bat-borne paramyxoviruses in the genus Henipavirus that cause severe and often fatal acute respiratory and/or neurologic diseases in humans and livestock. There are currently no approved antiviral therapeutics or vaccines for use in humans to treat or prevent NiV or HeV infection. To facilitate development of henipavirus antivirals, a high-throughput screening (HTS) platform was developed based on a well-characterized recombinant version of the nonpathogenic Henipavirus, Cedar virus (rCedV). Using reverse genetics, a rCedV encoding firefly luciferase (rCedV-Luc) was rescued and its utility evaluated for high-throughput antiviral compound screening. The luciferase reporter gene signal kinetics of rCedV-Luc in different human cell lines was characterized and validated as an authentic real-time measure of viral growth. The rCedV-Luc platform was optimized as an HTS assay that demonstrated high sensitivity with robust Z′ scores, excellent signal-to-background ratios and coefficients of variation. Eight candidate compounds that inhibited rCedV replication were identified for additional validation and demonstrated that 4 compounds inhibited authentic NiV-Bangladesh replication. Further evaluation of 2 of the 4 validated compounds in a 9-point dose response titration demonstrated potent antiviral activity against NiV-Bangladesh and HeV, with minimal cytotoxicity. This rCedV reporter can serve as a surrogate yet authentic BSL-2 henipavirus platform that will dramatically accelerate drug candidate identification in the development of anti-henipavirus therapies.

Structure and function analysis of a potent human neutralizing antibody CA521FALA against SARS-CoV-2

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the causative agent of the ongoing COVID-19 pandemic, which has resulted in more than two million deaths at 2021 February . There is currently no approved therapeutics for treating COVID-19. The SARS-CoV-2 Spike protein is considered a key therapeutic target by many researchers. Here we describe the identification of several monoclonal antibodies that target SARS-CoV-2 Spike protein. One human antibody, CA521FALA, demonstrated neutralization potential by immunizing human antibody transgenic mice. CA521FALA showed potent SARS-CoV-2-specific neutralization activity against SARS-CoV-2 pseudovirus and authentic SARS-CoV-2 infection in vitro. CA521FALA also demonstrated having a long half-life of 9.5 days in mice and 9.3 days in rhesus monkeys. CA521FALA inhibited SARS-CoV-2 infection in SARS-CoV-2 susceptible mice at a therapeutic setting with virus titer of the lung reduced by 4.5 logs. Structural analysis by cryo-EM revealed that CA521FALA recognizes an epitope overlapping with angiotensin converting enzyme 2 (ACE2)-binding sites in SARS-CoV-2 RBD in the Spike protein. CA521FALA blocks the interaction by binding all three RBDs of one SARS-CoV-2 spike trimer simultaneously. These results demonstrate the importance for antibody-based therapeutic interventions against COVID-19 and identifies CA521FALA a promising antibody that reacts with SARS-CoV-2 Spike protein to strongly neutralize its activity.

US Food and Drug Administration utilization of postmarketing requirements and postmarketing commitments, 2009-2018.

The US Food and Drug Administration outlines clinical studies as postmarketing requirements and commitments to be fulfilled following approval of new drugs and biologics ("therapeutics"). Regulators have increasingly emphasized lifecycle evaluation of approved therapeutics, and postmarketing studies are intended to advance our understanding of therapeutic safety and efficacy. However, little is known about the indications that clinical studies outlined in postmarketing requirements and commitments investigate, including whether they are intended to generate evidence for approved or other clinical indications. Therefore, we characterized US Food and Drug Administration postmarketing requirements and commitments for new therapeutics approved from 2009 to 2018. We conducted a cross-sectional study of all novel therapeutics, including small-molecule drugs and biologics, receiving original US Food and Drug Administration approval from 2009 to 2018, using approval letters accessed through the Drug@FDA database. Outcomes included the number and characteristics of US Food and Drug Administration postmarketing requirements and commitments for new therapeutics at original approval, including the types of studies outlined, the indications to be investigated, and the clinical evidence to be generated. From 2009 to 2018, the US Food and Drug Administration approved 343 new therapeutics with 1978 postmarketing requirements and commitments. Overall, 750 (37.9%) postmarketing requirements and commitments outlined clinical studies. For 71 of 343 (20.7%) therapeutics, no postmarketing requirements or commitments for clinical studies were outlined, while at least 1 was outlined for 272 (79.3%; median 2 (interquartile range: 1-4)). Among these 272 therapeutics, the number of postmarketing requirements and commitments for clinical studies per therapeutic did not change from 2009 (median: 2 (interquartile range: 1-4)) to 2018 (median: 2 (interquartile range: 1-3)). Among the 750 postmarketing requirements and commitments for clinical studies, 448 (59.7%) outlined new prospective cohort studies, registries, or clinical trials, while the remainder outlined retrospective studies, secondary analyses, or completion of ongoing studies. Although 455 (60.7%) clinical studies investigated only original approved therapeutic indications, 123 (16.4%) enrolled from an expansion of the approved disease population and 61 (8.1%) investigated diseases unrelated to approved indications. The US Food and Drug Administration approves most new therapeutics with at least 1 postmarketing requirement or commitment for a clinical study, and outlines investigations of safety or efficacy for both approved and unapproved indications. The median number of 2 clinical studies outlined has remained relatively constant over the last decade. Given increasing emphasis by the US Food and Drug Administration on faster approval and lifecycle evaluation of therapeutics, these findings suggest that more postmarketing requirements and commitments may be necessary to address gaps in the clinical evidence available for therapeutics at approval.

State of the structure address on MET receptor activation by HGF.

The MET receptor tyrosine kinase (RTK) and its cognate ligand hepatocyte growth factor (HGF) comprise a signaling axis essential for development, wound healing and tissue homeostasis. Aberrant HGF/MET signaling is a driver of many cancers and contributes to drug resistance to several approved therapeutics targeting other RTKs, making MET itself an important drug target. In RTKs, homeostatic receptor signaling is dependent on autoinhibition in the absence of ligand binding and orchestrated set of conformational changes induced by ligand-mediated receptor dimerization that result in activation of the intracellular kinase domains. A fundamental understanding of these mechanisms in the MET receptor remains incomplete, despite decades of research. This is due in part to the complex structure of the HGF ligand, which remains unknown in its full-length form, and a lack of high-resolution structures of the complete MET extracellular portion in an apo or ligand-bound state. A current view of HGF-dependent MET activation has evolved from biochemical and structural studies of HGF and MET fragments and here we review what these findings have thus far revealed.

Non-replicating adenovirus based Mayaro virus vaccine elicits protective immune responses and cross protects against other alphaviruses.

Mayaro virus (MAYV) is an alphavirus endemic to South and Central America associated with sporadic outbreaks in humans. MAYV infection causes severe joint and muscle pain that can persist for weeks to months. Currently, there are no approved vaccines or therapeutics to prevent MAYV infection or treat the debilitating musculoskeletal inflammatory disease. In the current study, a prophylactic MAYV vaccine expressing the complete viral structural polyprotein was developed based on a non-replicating human adenovirus V (AdV) platform. Vaccination with AdV-MAYV elicited potent neutralizing antibodies that protected WT mice against MAYV challenge by preventing viremia, reducing viral dissemination to tissues and mitigating viral disease. The vaccine also prevented viral-mediated demise in IFN⍺R1-/- mice. Passive transfer of immune serum from vaccinated animals similarly prevented infection and disease in WT mice as well as virus-induced demise of IFN⍺R1-/- mice, indicating that antiviral antibodies are protective. Immunization with AdV-MAYV also generated cross-neutralizing antibodies against two related arthritogenic alphaviruses-chikungunya and Una viruses. These cross-neutralizing antibodies were protective against lethal infection in IFN⍺R1-/- mice following challenge with these heterotypic alphaviruses. These results indicate AdV-MAYV elicits protective immune responses with substantial cross-reactivity and protective efficacy against other arthritogenic alphaviruses. Our findings also highlight the potential for development of a multi-virus targeting vaccine against alphaviruses with endemic and epidemic potential in the Americas.

A graphene oxide-based fluorescent nanosensor to identify antiviral agents via a drug repurposing screen

Currently, there are no approved therapeutics for Dengue virus (DENV) infection, even though it can cause fatal complications. Understanding DENV infection and its propagation process in host cells is necessary to develop specific antiviral therapeutics. Here, we developed a graphene oxide-based fluorescent system (Graphene Oxide-based Viral RNA Analysis system, GOViRA) that enables sensitive and quantitative real-time monitoring of the intracellular viral RNA level in living cells. The GOViRA system consists of a fluorescent dye-labeled peptide nucleic acid (PNA) with a complementary sequence to the DENV genome and a dextran-coated reduced graphene oxide nanocolloid (DRGON). When the dye labeled PNA is adsorbed onto DRGON, the fluorescence of the dye is effectively quenched. The quenched fluorescence signal is recovered when the dye labeled PNA forms interaction with intracellular viral RNA in DENV infected host cells. We demonstrated the successful use of the GOViRA platform for high-throughput screening to discover novel antiviral compounds. Through a cell-based high-throughput screening of FDA-approved small-molecule drugs, we identified ulipristal, a selective progesterone receptor modulator (SPRM), as a potent inhibitor against DENV infection. The anti-DENV activity of ulipristal was confirmed both in vitro and in vivo. Moreover, we suggest that the mode of action of ulipristal is mediated by inhibiting viral entry into the host cells.

Ross River Virus Infection: A Cross-Disciplinary Review with a Veterinary Perspective.

Ross River virus (RRV) has recently been suggested to be a potential emerging infectious disease worldwide. RRV infection remains the most common human arboviral disease in Australia, with a yearly estimated economic cost of $4.3 billion. Infection in humans and horses can cause chronic, long-term debilitating arthritogenic illnesses. However, current knowledge of immunopathogenesis remains to be elucidated and is mainly inferred from a murine model that only partially resembles clinical signs and pathology in human and horses. The epidemiology of RRV transmission is complex and multifactorial and is further complicated by climate change, making predictive models difficult to design. Establishing an equine model for RRV may allow better characterization of RRV disease pathogenesis and immunology in humans and horses, and could potentially be used for other infectious diseases. While there are no approved therapeutics or registered vaccines to treat or prevent RRV infection, clinical trials of various potential drugs and vaccines are currently underway. In the future, the RRV disease dynamic is likely to shift into temperate areas of Australia with longer active months of infection. Here, we (1) review the current knowledge of RRV infection, epidemiology, diagnostics, and therapeutics in both humans and horses; (2) identify and discuss major research gaps that warrant further research.

Proteomic Discovery of VEEV E2-Host Partner Interactions Identifies GRP78 Inhibitor HA15 as a Potential Therapeutic for Alphavirus Infections.

Alphaviruses are a genus of the Togaviridae family and are widely distributed across the globe. Venezuelan equine encephalitis virus (VEEV) and eastern equine encephalitis virus (EEEV), cause encephalitis and neurological sequelae while chikungunya virus (CHIKV) and Sindbis virus (SINV) cause arthralgia. There are currently no approved therapeutics or vaccines available for alphaviruses. In order to identify novel therapeutics, a V5 epitope tag was inserted into the N-terminus of the VEEV E2 glycoprotein and used to identify host-viral protein interactions. Host proteins involved in protein folding, metabolism/ATP production, translation, cytoskeleton, complement, vesicle transport and ubiquitination were identified as VEEV E2 interactors. Multiple inhibitors targeting these host proteins were tested to determine their effect on VEEV replication. The compound HA15, a GRP78 inhibitor, was found to be an effective inhibitor of VEEV, EEEV, CHIKV, and SINV. VEEV E2 interaction with GRP78 was confirmed through coimmunoprecipitation and colocalization experiments. Mechanism of action studies found that HA15 does not affect viral RNA replication but instead affects late stages of the viral life cycle, which is consistent with GRP78 promoting viral assembly or viral protein trafficking.

Design and Characterization of an Intracellular Covalent Ligand for CC Chemokine Receptor 2

Covalently acting inhibitors constitute a large and growing fraction of approved small-molecule therapeutics as well as useful tools for a variety of in vitro and in vivo applications. Here, we aimed to develop a covalent antagonist of CC chemokine receptor 2 (CCR2), a class A GPCR that has been pursued as a therapeutic target in inflammation and immuno-oncology. Based on a known intracellularly binding CCR2 antagonist, several covalent derivatives were synthesized and characterized by radioligand binding and functional assays. These studies revealed compound 14 as an intracellular covalent ligand for CCR2. In silico modeling followed by site-directed mutagenesis confirmed that 14 forms a covalent bond with one of three proximal cysteine residues, which can be engaged interchangeably. To our knowledge, compound 14 represents the first covalent ligand reported for CCR2. Due to its unique properties, it may represent a promising tool for ongoing and future studies of CCR2 pharmacology.

Characterizing Native and Hydrocarbon-Stapled Enfuvirtide Conformations with Ion Mobility Mass Spectrometry and Hydrogen-Deuterium Exchange.

The number of approved peptide therapeutics, as well as those in development, has been increasing in recent years. Frequently, the biological activity of such peptides is elicited through the adoption of secondary structural elements upon interaction with their cellular target. However, many therapeutic peptides are unstructured in solution and accordingly exhibit a poor bioavailability due to rapid proteolysis in vivo. To combat this degradation, numerous naturally occurring peptides with therapeutic properties contain stabilizing features, such as N-to-C cyclization or disulfide bonds. Recently, hydrocarbon stapling via non-native amino acid substitution followed by ring-closing metathesis has been shown to induce a dramatic stabilization of α-helical peptides. Identifying the ideal staple location along the peptide backbone is a critical developmental step, and methods to streamline this optimization are needed. Mass spectrometry-based methods such as ion mobility (IM) and hydrogen-deuterium exchange (HDX) can detect multiple discrete peptide conformations, a significant advantage over bulk spectroscopic techniques. In this study we use IM-MS and HDX-MS to demonstrate that the native 36-residue enfuvirtide peptide is highly dynamic in solution and the conformational ensemble populated by stabilized constructs depends heavily on the staple location. Further, our measurements yielded results that correlate well with the average α-helical content measured by circular dichroism. The MS-based approaches described herein represent sensitive and potentially high-throughput methods for characterizing and identifying optimally stapled peptides.

Hepatic in vitro metabolism of peptides; Comparison of human liver S9, hepatocytes and Upcyte hepatocytes with cyclosporine A, leuprorelin, desmopressin and cetrorelix as model compounds

The number of approved peptide therapeutics has increased significantly in recent years. Peptide therapeutics have many advances over small molecule drugs, such as higher affinity to target and lower toxicity profiles. Although peptide-like drugs are mainly metabolized/catabolized in the body for smaller peptides and amino acids, metabolite identification still has an essential part of in their development, especially if their structure contains modified amino acids, and also to identify the metabolic soft spots enabling modification to more stable sequence. The use of human derived in vitro systems is an important tool when investigating metabolism of peptide drugs, and comparison of results by various hepatic systems was investigated here. Peptides were incubated in several different in vitro human liver-derived subcellular and cellular incubation systems, i.e. liver S9 fraction, suspended cryo-preserved human primary hepatocytes and plated Upcyte hepatocytes. Samples were collected at different time points and analysed by UPLC/HR-MS-method developed for the purpose. Both substrate disappearance and metabolite formation were monitored, and the systems were compared. S9 fraction formed the highest number of metabolites for leuprorelin and cetrorelix, while for desmopressin and cyclosporin, primary hepatocytes and liver S9 produced similar metabolite profiles. Interestingly, not only cyclosporin, but also leuprorelin and cetrorelix showed metabolites whose formation was CYP (NADPH) dependent in liver S9. For leuprorelin and cetrorelix, the metabolites that showed NADPH dependency with liver S9, were not detected with hepatocytes, even though for leuprorelin these reactions played a major role in liver S9. The hydrolytic metabolic reactions were very similar between liver S9 and hepatocytes, i.e. the metabolite profiles in hepatocytes matched better with liver S9 profiles without NADPH, which may be caused by cell uptake rate limitation with hepatocytes, or then hydrolytic processes are more stressed in peptide metabolism with hepatocytes, in comparison to CYP-mediated processes.

Crossing the T’s on Norovirus

Human noroviruses (NoVs) are highly contagious viral pathogens and the leading cause of virally induced gastroenteritis across all age groups.1 Currently, there are no approved therapeutics or vaccines available against NoVs. Adaptive immune control of NoVs in humans, especially humoral antibody responses, has been intensively analyzed in clinical settings, but T cell responses against NoVs have generally been understudied. NoV vaccine design has predominantly focused on antibody-mediated protection, targeting the structural portions of NoVs, but their success thus far has been limited.

Mechanisms of Immune Evasion by Ebola Virus.

The 2013-2016 Ebola virus epidemic in West Africa, which also spread to the USA, UK and Europe, was the largest reported outbreak till date (World Health Organization. 2016. https://apps.who.int/iris/bitstream/handle/10665/208883/ebolasitrep_10Jun2016_eng.pdf;jsessionid=8B7D74BC9D82D2BE1B110BAFFAD3A6E6?sequence=1 ). The recentEbola outbreak in the Democratic Republic of the Congo has raised immense global concern on this severe and often fatal infection. Although sporadic, the severity and lethality of Ebola virus disease outbreaks has led to extensive research worldwide on this virus.Vaccine (World Health Organization. 2016. https://www.who.int/en/news-room/detail/23-12-2016-final-trial-results-confirm-ebola-vaccine-provides-high-protection-against-disease ; Henao-Restrepo et al. Lancet 389:505-518, 2017) and drug (Hayden. Nature, 557, 475-476, 2018; Dyall et al. J Infect Dis 218(suppl_5), S672-S678, 2018) development efforts against Ebola virus areresearch hotspots,and a fewapproved therapeutics are currently available(Centers for Disease Control and Prevention. 2021. https://www.cdc.gov/vhf/ebola/clinicians/vaccine/index.html; Centers for Disease Control and Prevention. 2021.https://www.cdc.gov/vhf/ebola/treatment/index.html). Ebola virus has evolved several mechanisms of host immune evasion, which facilitate its replication and pathogenesis. This chapter describes the Ebola virus morphology, genome, entry, replication, pathogenesis and viral proteins involved in host immune evasion. Further understanding of the underlying molecular mechanisms of immune evasion may facilitate development of additionalnovel and sustainable strategies against this deadly virus.

Discovery of mushroom-derived bioactive compound's draggability against nsP3 macro domain, nsP2 protease and envelope glycoprotein of Chikungunya virus: An in silico approach

The emerging mosquito-borne Chikungunya virus (CHIKV) infection is a massive threat in tropical areas and is rapidly expanding towards the temperate zones. This virus is causing recent epidemics worldwide, predominantly in Europe and North America. Moreover, CHIKV has a mounting impact on persons with possibly painful arthritis. Millions of positive cases have already been recorded in more than 100 countries worldwide. This virus is also capable of infecting new areas by travelers, which has made it more dreadful. However, for the dearth of approved therapeutics or vaccines to prevent or control the virus, it is essential to identify new and effective medicinal compounds to address this. Therefore, the non-structural protein nsP3 macro domain, nsP2 protease, and envelope proteins responsible for viral replication are the new target sites for therapeutic development. Mushrooms are abundant in bioactive compounds with antiviral properties. Thus, we performed molecular docking (MD) and dynamics simulation to identify the top candidates for nsP3 macro domains, nsP2 protease, and envelope glycoprotein complex inhibitors, as well as to predict possible therapeutic candidates. We then predicted the drug similarity for the best candidates based on higher binding affinity. Our findings suggest that mushroom-derived heliantriol F, semicochliodinol A, and semicochliodinol B are the best inhibitors. Based on the ligand, the predicted drugs allylestrenol (DB01431), calcitriol (DB00136), calcidiol (DB00146), benzonatate (DB02659), and gallamine triethiodide (DB00459) are recommended as alternative therapies for CHIKV.

Lack of Robust Laboratory Testing Infrastructure in Nigeria: A Promoter of Community Transmission Outcome of COVID 19 Virus Indicator

Background: An outbreak of unknown origin which broke out in China in December 2019 has become a global threat to human lives and economies. Coronavirus disease 2019 (COVID19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) was declared a pandemic by the World Health Organisation (WHO) due to its rapid global spread and concurrent of level devastation. Many countries are currently on lockdown to mitigate the spread while different treatment options have been proposed, but none has been approved by the appropriate authority. Currently, the disease has affected over 10 million people worldwide while claiming as many as 517,877 lives respectively. Aim: To evaluate the inadequate COVID-19 testing capacity in Nigeria, probable causes and how it can promote community transmission of the disease Methodology: Peer-reviewed published research articles containing information on COVID-19, the causative virus and other important details were systematically appraised and summarized. The reviewed studies comprise of cross-sectional and observational studies of wide range of outcome. Findings: COVID-19 which first broke out in Wuhan City of China has now spread to about 216 countries, causing fatalities in large numbers. It has been reported that individuals with increased risk of severe outcomes include the elderly and those with underlying health conditions. The incubation period of the disease ranges from 1-14 days, during which the disease can be transmitted by both symptomatic and asymptomatic patients. Patients manifest with symptoms such as fever, dry cough, dyspnoea, etc., while the major causes of death include multi-targeted organ failure, acute respiratory distress syndrome (ARDS), shock, etc. The disease can be diagnosed by the detection of the nucleic acid of SARS-CoV-2 in patient samples via real-time reverse-transcription polymerase chain reaction (rRT-PCR). Since there is currently no approved therapeutics or vaccine for the disease, early detection and management of symptoms represent the best way of helping patients to recover in good time. While many countries are responding by scaling up their testing capacities, Nigeria has struggled to scale up her testing capacity to a reasonable extent, though not really enough in capacity and robustness, considering the large population size to cover in the country, and this therefore, may pose huge amount of threat of increased community transmission of the disease in our neighbourhood, if not corrected in time Conclusion/recommendation: The leadership of Nigeria agency in-charge of disease control and prevention needs to scale up the testing capacity within the country, as soon as possible to reduce the risk of increased transmission of the disease, while reassuring the inhabitants of the hope and capacity of overcoming the outbreak. It is also very important that long-term development strategies be put in place to revamp the weak health care facilities in the country, with respect to provision of modern technological advanced medical equipment’s and the training of manpower to cover the already existing shortage of expertise in molecular diagnosis and research outcome

FGF21: An Emerging Therapeutic Target for Non-Alcoholic Steatohepatitis and Related Metabolic Diseases.

The rising global prevalence of obesity, metabolic syndrome, and type 2 diabetes has driven a sharp increase in non-alcoholic fatty liver disease (NAFLD), characterized by excessive fat accumulation in the liver. Approximately one-sixth of the NAFLD population progresses to non-alcoholic steatohepatitis (NASH) with liver inflammation, hepatocyte injury and cell death, liver fibrosis and cirrhosis. NASH is one of the leading causes of liver transplant, and an increasingly common cause of hepatocellular carcinoma (HCC), underscoring the need for intervention. The complex pathophysiology of NASH, and a predicted prevalence of 3–5% of the adult population worldwide, has prompted drug development programs aimed at multiple targets across all stages of the disease. Currently, there are no approved therapeutics. Liver-related morbidity and mortality are highest in more advanced fibrotic NASH, which has led to an early focus on anti-fibrotic approaches to prevent progression to cirrhosis and HCC. Due to limited clinical efficacy, anti-fibrotic approaches have been superseded by mechanisms that target the underlying driver of NASH pathogenesis, namely steatosis, which drives hepatocyte injury and downstream inflammation and fibrosis. Among this wave of therapeutic mechanisms targeting the underlying pathogenesis of NASH, the hormone fibroblast growth factor 21 (FGF21) holds considerable promise; it decreases liver fat and hepatocyte injury while suppressing inflammation and fibrosis across multiple preclinical studies. In this review, we summarize preclinical and clinical data from studies with FGF21 and FGF21 analogs, in the context of the pathophysiology of NASH and underlying metabolic diseases.

Molecular basis of pangolin ACE2 engaged by COVID-19 virus

<p indent="0mm">The virus caused coronavirus disease 2019 (COVID-19 virus), also called severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), is the seventh coronavirus that can infect humans, and belongs to the genus β-coronavirus in the family <italic>Coronaviridae</italic>. As of 5 November 2020, SARS-CoV-2 has caused &gt;47000000 confirmed cases and &gt;1200000 related deaths in 219 countries and regions, bringing great challenges to global public health. Currently, there is no approved therapeutics or vaccines for the treatment of this disease. Several studies suggested SARS-CoV-2 might have originated from bats based on phylogenetic analysis, but the intermediate host of the virus is still unknown. Besides humans, cats, dogs, tigers, lions, minks, and other species have been reported to be infected by SARS-CoV-2. Several studies have reported pangolins as the only other mammalian species carrying coronaviruses related to SARS-CoV-2 besides bats, and suggested pangolins might be the intermediate host of SARS-CoV-2. Previously, we and other groups identified the angiotensin converting enzyme 2 (ACE2), the receptor of SARS-CoV, also functions as the entry receptor of SARS-CoV-2 and is recognized by the receptor binding domain (RBD) of the spike protein (S). Then, we elucidated the interaction between SARS-CoV-2 RBD and human ACE2 (hACE2) or cat ACE2 (cACE2), and also found that SARS-CoV-2 had broad potential host range, including domestic animals, companion pets and wild animals. In this study, we investigated the binding features of SARS-CoV-2 and two pangolin coronaviruses (pangolin-CoVs, GX/P2V/2017 and GD/1/2019) that recognize the receptors of both pangolin ACE2 (pACE2) and hACE2 using surface plasmon resonance (SPR) and structural methods. We further determined the crystal structure of SARS-CoV-2 S (RBD) in complex with pACE2 at a 2.3 Å resolution, revealing the similarity in the binding mode between SARS-CoV-2 RBD to hACE2 and to cACE2. Interestingly, we found that the SARS-CoV-2 RBD-pACE2 complex is more similar to the SARS-CoV-2 RBD-hACE2 complex than to SARS-CoV-2 RBD-cACE2 complex. Furthermore, we modeled the interactions of GX/P2V/2017 RBD and GD/1/2019 RBD bound to pACE2 and hACE2, respectively, and found that both viruses adopted similar binding mode as SARS-CoV-2 RBD to pACE2 and hACE2. However, crystal structure and homology modeling implied that the interaction between the three RBDs and pACE2 were slightly weaker than their respective binding to hACE2, which was consistent with the receptor-RBD protein interaction measured by SPR. These results could facilitate better understanding of SARS-CoV-2 evolution, indicate the potential of pangolin-CoVs to enter human population that may lead to another outbreak, and highlight the importance of monitoring pangolin CoVs to prevent possible spillovers.

AO-176, a Highly Differentiated Clinical Stage Anti-CD47 Antibody, Exerts Potent Anti-Tumor Activity in Preclinical Models of Multiple Myeloma As a Single Agent and in Combination with Approved Therapeutics

Upregulation of tumor CD47, the "don't eat me" signal, to evade immune surveillance is a common escape mechanism that evolves during cancer development, progression, and relapse. Previous studies have shown multiple myeloma (MM) cells leverage this mechanism through broad upregulation of CD47 compared to non-malignant plasma cells, making CD47 an attractive therapeutic target for this disease. We recently reported that AO-176, a clinical stage humanized anti-CD47 IgG2 antibody, possesses differentiated characteristics such as preferential binding of tumor cells compared to normal cells, a lack of binding to red blood cells, non-ADCC direct tumor killing and elicits immunogenic cell death with DAMP induction, all in addition to single-agent phagocytosis. In this study, AO-176's anti-tumor activity in MM was evaluated. Immunohistochemical analyses of MM patient tumors with upregulated CD47 expression showed infiltration of innate immune cells such as macrophages and dendritic cells, both previously shown to be involved in anti-CD47 antibody mechanisms of action. AO-176 binding was confirmed on human cell lines frequently used in MM xenograft models. AO-176 exerted substantial single agent in vivo anti-tumor activity in multiple MM xenograft models when dosed at 25 mg/kg, including significant tumor growth inhibition of RPMI-8226 xenografted mice, and complete responses (CRs) in (10/10) NCI-H929 xenografted mice. These CRs were durable, with treated mice tumor-free up to 120 days post antibody dosing. Immunohistochemical analysis of AO-176 treated tumors from both models showed increased numbers of macrophages and dendritic cells compared to controls. An AO-176 dose response study resulted in CRs and increases in overall survival down to 10 mg/kg, with CRs observed as low as 3 mg/kg during dosing. In addition, we found that large NCI-H929 tumors (up to 1600mm3) showed pronounced regression after AO-176 treatment. The anti-tumor activity of AO-176 was also evaluated in combination with several standard of care MM therapies. When combined with the proteasome inhibitor bortezomib, AO-176 treatment at both 10 mg/kg and 25 mg/kg resulted in profound RPMI-8226 xenograft growth inhibition, near-total CRs (19/20 mice), and extended survival at both doses. Combining AO-176 and the anti-CD38 antibody daratumumab or immunomodulatory drugs (lenalidomide/pomalidomide) both produced significant enhancement of anti-tumor activity in xenograft models. The combined regimen of AO-176 with daratumumab led to significant MM.1S tumor growth inhibition compared to AO-176 or daratumumab alone. Both lenalidomide and pomalidomide combined with AO-176 resulted in significantly increased MM.1S tumor growth inhibition and extended survival compared to AO-176 alone, with an increased number of CRs observed in the combination groups compared to monotherapy groups. In summary, the pre-clinical potent single agent activity and enhanced activity when combined with standard of care anti-MM agents, warrants further development of AO-176 in MM treatment. AO-176 is being evaluated in phase 1 clinical trials for the treatment of patients with solid tumors (NCT03834948) and with MM (NCT04445701). Disclosures Wilson: Arch Oncology: Current Employment, Current equity holder in private company. Richards:Arch Oncology: Current Employment, Current equity holder in private company. Puro:Arch Oncology: Current Employment, Current equity holder in private company. Andrejeva:Arch Oncology: Current Employment, Current equity holder in private company. Capoccia:Arch Oncology: Current Employment, Current equity holder in private company. Donio:Arch Oncology: Current Employment, Current equity holder in private company. Hiebsch:Arch Oncology: Current Employment, Current equity holder in private company. Chakraborty:Arch Oncology: Current Employment, Current equity holder in private company. Sung:Arch Oncology: Current Employment, Current equity holder in private company. Pereira:Arch Oncology: Current Employment, Current equity holder in private company.