Artemisinin and Its Derivatives as a Repurposing Anticancer Agent: What Else Do We Need to Do?

Preclinical investigation and clinical experience have provided evidence on the potential anticancer effect of artemisinin and its derivatives (ARTs) in the recent two decades. The major mechanisms of action of ARTs may be due to toxic-free radicals generated by an endoperoxide moiety, cell cycle arrest, induction of apoptosis, and inhibition of tumor angiogenesis. It is very promising that ARTs are expected to be a new class of antitumor drugs of wide spectrum due to their detailed information regarding efficacy and safety. For developing repurposed drugs, many other characteristics of ARTs should be studied, including through further investigations on possible new pathways of anticancer effects, exploration on efficient and specific drug delivery systems-especially crossing biological barriers, and obtaining sufficient data in clinical trials. The aim of this review is to highlight these achievements and propose the potential strategies to develop ARTs as a new class of cancer therapeutic agents.

A Repurposed Drug Screen Identifies Compounds That Inhibit the Binding of the COVID-19 Spike Protein to ACE2

Repurposed drugs that block the interaction between the SARS-CoV-2 spike protein and its receptor ACE2 could offer a rapid route to novel COVID-19 treatments or prophylactics. Here, we screened 2,701 compounds from a commercial library of drugs approved by international regulatory agencies for their ability to inhibit the binding of recombinant, trimeric SARS-CoV-2 spike protein to recombinant human ACE2. We identified 56 compounds that inhibited binding in a concentration-dependent manner, measured the IC50 of binding inhibition, and computationally modeled the docking of the best inhibitors to the Spike-ACE2 binding interface. The best candidates were Thiostrepton, Oxytocin, Nilotinib, and Hydroxycamptothecin with IC50's in the 4-9 μM range. These results highlight an effective screening approach to identify compounds capable of disrupting the Spike-ACE2 interaction, as well as identify several potential inhibitors of the Spike-ACE2 interaction.

Real-World Inpatient Use of Medications Repurposed for Coronavirus Disease 2019 in United States Hospitals, March-May 2020

We report off-label use patterns for medications repurposed for coronavirus disease 2019 (COVID-19) at 318 US hospitals. Inpatient hydroxychloroquine use declined by 80%, whereas corticosteroids and tocilizumab were initiated 2 days earlier in May versus March 2020. Two thirds of ventilated COVID-19 patients were already receiving corticosteroids during March-May 2020, resembling pre-COVID use in mechanically ventilated influenza patients.

Inhaled antifungal therapy: benefits, challenges, and clinical applications

INTRODUCTION

Disease due to pulmonary infection with Aspergillus, and other emerging opportunistic fungi remains a significant unmet need. Existing antifungal medicines are predominantly dosed either orally or systemically, but because of limited exposure to the lung lumen, adverse events, and problematic drug-drug interactions, inhaled treatment could provide an attractive option.

AREA COVERED

This review summarizes 1) the limitations of current antifungal therapy, 2) the beneficial effects of inhaled antifungal agents, 3) the clinical development of inhaled antifungal triazoles (repurposed with an innovative inhalation system or a novel inhaled agent) for the treatment of pulmonary fungal infections, and 4) the difficulties and challenges of inhaled antifungal agent development. Regrettably, details of novel inhaled devices or formulations were not covered.

EXPERT OPINION

Inhaled antifungal treatment could provide an attractive option by shifting the risk benefit ratio of treatment favorably. Preclinical and clinical studies with inhaled antifungal agents (off-label use) are encouraging so far. New inhaled antifungal triazoles are well tolerated in early clinical studies and warrant further clinical development. However, challenges remain and many unaddressed issues including required preclinical studies, appropriate clinical design, pharmacokinetics, delivery system(s) and regulatory process need to be resolved. Early communication with regulatory authorities is therefore recommended.

Repurposing Existing Medications for Coronavirus Disease 2019: Protocol for a Rapid and Living Systematic Review

BACKGROUND

Coronavirus Disease 2019 (COVID-19) has no known specific treatments. However, there might be in vitro and early clinical data as well as evidence from Severe Acute Respiratory Syndrome and Middle Eastern Respiratory Syndrome that could inform clinicians and researchers. This systematic review aims to create priorities for future research of drugs repurposed for COVID-19.

METHODS

This systematic review will include in vitro, animal, and clinical studies evaluating the efficacy of a list of 34 specific compounds and four groups of drugs identified in a previous scoping review. Studies will be identified both from traditional literature databases and pre-print servers. Outcomes assessed will include time to clinical improvement, time to viral clearance, mortality, length of hospital stay, and proportions transferred to the intensive care unit and intubated, respectively. We will use the GRADE methodology to assess the quality of the evidence.

DISCUSSION

The challenge posed by COVID-19 requires not just a rapid review of drugs that can be repurposed but also a sustained effort to integrate new evidence into a living systematic review.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO 2020 CRD42020175648.

A Cell-Based Renilla Luminescence Reporter Plasmid Assay for High-Throughput Screening to Identify Novel FDA-Approved Drug Inhibitors of HPV-16 Infection

Like cervical cancer, anal cancer is caused by human papillomavirus (HPV). HPV is the most common sexually transmitted agent and is found in the anal canal of almost all HIV-positive men who have sex with men (MSM). Rates of HPV anal cancer are disproportionately higher in this population. Although the nanovalent HPV vaccine is efficacious in protecting against oncogenic HPV types, a substantial proportion of MSM remains unvaccinated and anal HPV infection continues to be an important public health burden. Therefore, it is important to identify strategies to prevent HPV infection. We report on two promising and interlinked strategies: (1) the development of a cell-based Renilla luminescence reporter assay using HPV-16 pseudovirions that encapsidate SV40-driven Renilla luminescence reporter expression plasmid and (2) use of this assay for high-throughput screening (HTS) of FDA- and internationally approved drugs to identify those that could be repurposed to prevent HPV infection. We conducted a screen of 1906 drugs. The assay was valid with a Z' of 0.67 ± 0.04, percent coefficient of variance of 10.0, and signal-to-background noise window of 424.0 ± 8.0. Five drugs were chosen for further analyses based on selection parameters of ≥77.0% infection of HPV-16 pseudovirion-driven Renilla expression with <20.0% cytotoxicity. Of these, the antifungal pentamidine and a gamma-amino butyric acid receptor agonist securinine exhibited ≥90.0% infection with <10.0% cytotoxicity. This luminescent cell-based reporter expression plasmid assay for HTS is a valid method to identify FDA- and internationally approved drugs with the potential to be repurposed into prevention modalities for HPV infection.

In silico Antivirus Repurposing and its Modification to Organoselenium Compounds as SARS-CoV-2 Spike Inhibitors

&lt;b&gt;Background and Objective:&lt;/b&gt; The COVID-19, which has been circulating since late 2019, is caused by SARS-CoV-2. Because of its high infectivity, this virus has spread widely throughout the world. Spike glycoprotein is one of the proteins found in SARS-CoV-2. Spike glycoproteins directly affect infection by forming ACE-2 receptors on host cells. Inhibiting glycoprotein spikes could be one method of treating COVID-19. In this study, the antivirus marketed as a database will be repurposed into an antiviral SARS-CoV-2 and the selected compounds will be modified to become organoselenium compounds. &lt;b&gt;Materials and Methods:&lt;/b&gt; The research was carried out using &lt;i&gt;in silico&lt;/i&gt; methods, such as rigid docking and flexible docking. To obtain information about the interaction between spike glycoprotein and ligands, MOE 2014.09 was used to perform the molecular docking simulation. &lt;b&gt;Results:&lt;/b&gt; The analysis of binding energy values was used to select the ten best ligands from the first stage of the molecular docking simulation, which was then modified according to the previous QSAR study to produce 96 new molecules. The second stage of molecular docking simulation was performed with modified molecules. The best-modified ligand was chosen by analyzing the ADME-Tox property, RMSD value and binding energy value. &lt;b&gt;Conclusion:&lt;/b&gt; The best three unmodified ligands, Ombitasvir, Elbasvir and Ledipasvir, have a binding energy value of -15.8065, -15.3842 and -15.1255 kcal mol&lt;sup&gt;1&lt;/sup&gt;, respectively and the best three modified ligands ModL1, ModL2 and ModL3 has a binding value of -15.6716, -13.9489 and -13.2951 kcal mol&lt;sup&gt;1&lt;/sup&gt;, respectively with an RMSD value of 1.7109 Å, 2.3179 Å and 1.7836 Å.

Quality by design (QbD) based approach for development of itraconazole-loaded transferosomes for skin cancer: in vitro, ex vivo and cell line studies

OBJECTIVE

Itraconazole (ITZ), a widely used systemic antifungal drug, has been ingeniously repurposed for its antitumor effects. In the present work, we have prepared and optimized the ITZ-loaded transferosomes by Quality by Design (QbD) approach and repurposed them for skin cancer.

METHODS

The transferosomal formulation was optimized by employing a QbD approach with the design of experiment. A combination of screening and optimization design was used for formulation optimization. The optimized formulation was characterized by particle size, PDI, zeta potential, FTIR, XRD, and surface morphology using TEM. In vitro and ex vivo studies were performed using Franz diffusion cells. An in vitro cell line study was performed on the human melanoma A375 cell line.

RESULTS

The optimized formulation has a particle size of 192.37 ± 13.19 nm, PDI of 0.41 ± 0.03, zeta potential -47.80 ± 3.66, and an entrapment efficiency of 64.11 ± 3.75%. In vitro release studies showed that ITZ encapsulated transferosomes offer higher and sustained release than pure drugs. Ex vivo drug penetration and retention studies show that the penetration and retention of transferosomes are more visible in the skin than in the drug. The cell viability study confirms that ITZ encapsulated transferosomes have almost 2-fold more potency against the A375 cell line than pure drug.

CONCLUSION

ITZ encapsulated transferosomes were successfully prepared and optimized using a combination of screening and optimization designs. Based on ex vivo and cell line studies, we conclude that ITZ-loaded transferosomes could aid melanoma management alongside standard therapies.

IPIAD- an augmentation regimen added to standard treatment of pancreatic ductal adenocarcinoma using already-marketed repurposed drugs irbesartan, pyrimethamine, itraconazole, azithromycin, and dapsone

This short note presents the data and rationale for adding five generic non-oncology drugs from general medical practice to gemcitabine, nab-paclitaxel, a current standard cytotoxic chemotherapy of pancreatic ductal adenocarcinoma. The regimen, called IPIAD, uses an angiotensin receptor blocker (ARB) irbesartan indicated for treating hypertension, an old antimicrobial drug pyrimethamine indicated for treating toxoplasmosis or malaria, an old antifungal drug itraconazole, an old broad spectrum antibiotic azithromycin and an old antibiotic dapsone. In reviewing selected growth driving systems active in pancreatic ductal adenocarcinoma then comparing these with detailed data on ancillary attributes of the IPIAD drugs, one can predict clinical benefit and slowing growth of pancreatic ductal adenocarcinoma by this augmentation regimen.

Probenecid Inhibits Human Metapneumovirus (HMPV) Replication In Vitro and in BALB/c Mice

Human metapneumovirus (HMPV) is an important cause of acute respiratory tract infection and causes significant morbidity and mortality. There is no specific antiviral drug to treat HMPV or vaccine to prevent HMPV. This study determined if probenecid, a host-targeting antiviral drug, had prophylactic (pre-virus) or therapeutic (post-virus) efficacy to inhibit HMPV replication in LLC-MK2 cells in vitro and in the lungs of BALB/c mice. This study showed that ≥0.5 μM probenecid significantly inhibited HMPV replication in vitro, and 2-200 mg/kg probenecid prophylaxis or treatment reduced HMPV replication in BALB/c mice.