Long-term safety and efficacy of ozanimod in relapsing multiple sclerosis: Up to 5 years of follow-up in the DAYBREAK open-label extension trial.

BACKGROUND: Ozanimod, an oral sphingosine 1-phosphate receptor 1 and 5 modulator, is approved in multiple countries for treatment of relapsing forms of MS. OBJECTIVE: To characterize long-term safety and efficacy of ozanimod. METHODS: Patients with relapsing MS who completed a phase 1‒3 ozanimod trial were eligible for an open-label extension study (DAYBREAK) of ozanimod 0.92 mg/d. DAYBREAK began 16 October 2015; cutoff for this interim analysis was 2 February 2021. RESULTS: This analysis included 2494 participants with mean 46.8 (SD 11.9; range 0.033‒62.7) months of ozanimod exposure in DAYBREAK. During DAYBREAK, 2143 patients (85.9%) had treatment-emergent adverse events (TEAEs; similar in nature to those in the parent trials), 298 (11.9%) had a serious TEAE, and 75 (3.0%) discontinued treatment due to TEAEs. Serious infections (2.8%), herpes zoster infections (1.7%), confirmed macular edema cases (0.2%), and cardiac TEAEs (2.8%) were infrequent. Adjusted annualized relapse rate was 0.103 (95% confidence interval, 0.086‒0.123). Over 48 months, 71% of patients remained relapse free. Adjusted mean numbers of new/enlarging T2 lesions/scan and gadolinium-enhancing lesions were low and similar across parent trial treatment subgroups. CONCLUSIONS: This long-term extension of ozanimod trials confirmed a favorable safety/tolerability profile and sustained benefit on clinical and magnetic resonance imaging measures of disease activity.

1,3,4-oxadiazole derivatives as potential antimicrobial agents.

Due to the emergence of drug-resistant microbial strains, different research groups are continuously developing novel drug molecules against already exploited and unexploited targets. 1,3,4-Oxadiazole derivatives exhibited noteworthy antimicrobial activities. The presence of 1,3,4-oxadiazole moiety in antimicrobial agents can modify their polarity and flexibility, which significantly improves biological activities due to various bonded and non-bonded interactions viz. hydrogen bond, steric, electrostatic, and hydrophobic with target sites. The present review elaborates the therapeutic targets and mode of interaction of 1,3,4-oxadiazoles as antimicrobial agents. 1,3,4-oxadiazole derivatives target enoyl reductase (InhA), 14α-demethylase in the mycobacterial cell; GlcN-6-P synthase, thymidylate synthase, peptide deformylase, RNA polymerase, dehydrosqualene synthase in bacterial strains; ergosterol biosynthesis pathway, P450-14α demethylase, protein-N-myristoyltransferase in fungal strains; FtsZ protein, interfere with purine and functional protein synthesis in plant bacteria. The present review also summarizes the effect of different moieties and functional groups on the antimicrobial activity of 1,3,4-oxadiazole derivatives.

Discovery of honokiol thioethers containing 1,3,4-oxadiazole moieties as potential α-glucosidase and SARS-CoV-2 entry inhibitors.

Honokiol, isolated from a traditional Chinese medicine (TCM) Magnolia officinalis, is a biphenolic compound with several biological activities. To improve and broaden its biological activity, herein, two series of honokiol thioethers bearing 1,3,4-oxadiazole moieties were prepared and assessed for their α-glucosidase and SARS-CoV-2 entry inhibitory activities. Among all the honokiol thioethers, compound 7l exhibited the strongest α-glucosidase inhibitory effect with an IC50 value of 18.9 ± 2.3 µM, which was superior to the reference drug acarbose (IC50 = 24.4 ± 0.3 µM). Some interesting results of structure-activity relationships (SARs) have also been discussed. Enzyme kinetic study demonstrated that 7l was a noncompetitive α-glucosidase inhibitor, which was further supported by the results of molecular docking. Moreover, honokiol thioethers 7e, 9a, 9e, and 9r exhibited potent antiviral activity against SARS-CoV-2 pseudovirus entering into HEK-293 T-ACE2h. Especially 9a displayed the strongest inhibitory activity against SARS-CoV-2 pseudovirus entry with an IC50 value of 16.96 ± 2.45 µM, which was lower than the positive control Evans blue (21.98 ± 1.98 µM). Biolayer interferometry (BLI) binding and docking studies suggested that 9a and 9r may effectively block the binding of SARS-CoV-2 to the host ACE2 receptor through dual recognition of SARS-CoV-2 spike RBD and human ACE2. Additionally, the potent honokiol thioethers 7l, 9a, and 9r displayed relatively no cytotoxicity to normal cells (LO2). These findings will provide a theoretical basis for the discovery of honokiol derivatives as potential both α-glucosidase and SARS-CoV-2 entry inhibitors.

Comparative Study of the Synthetic Approaches and Biological Activities of the Bioisosteres of 1,3,4-Oxadiazoles and 1,3,4-Thiadiazoles over the Past Decade.

The bioisosteres of 1,3,4-oxadiazoles and 1,3,4-thiadiazoles are well-known pharmacophores for many medicinally important drugs. Throughout the past 10 years, 1,3,4-oxa-/thiadiazole nuclei have been very attractive to researchers for drug design, synthesis, and the study of their potential activity towards a variety of diseases, including microbial and viral infections, cancer, diabetes, pain, and inflammation. This work is an up-to-date comparative study that identifies the differences between 1,3,4-thiadiazoles and 1,3,4-oxadiazoles concerning their methods of synthesis from different classes of starting compounds under various reaction conditions, as well as their biological activities and structure-activity relationship.

A review on synthetic account of 1,2,4-oxadiazoles as anti-infective agents.

Most of the currently marketed drugs consist of heterocyclic scaffolds containing nitrogen and or oxygen as heteroatoms in their structures. Several research groups have synthesized diversely substituted 1,2,4-oxadiazoles as anti-infective agents having anti-bacterial, anti-viral, anti-leishmanial, etc. activities. For the first time, the present review article will provide the coverage of synthetic account of 1,2,4-oxadiazoles as anti-infective agents along with their potential for SAR, activity potential, promising target for mode of action. The efforts have been made to provide the chemical intuitions to the reader to design new chemical entity with potential of anti-infective activity. This review will mark the impact as the valuable, comprehensive and pioneered work along with the library of synthetic strategies for the organic and medicinal chemists for further refinement of 1,2,4-oxadiazole as anti-infective agents.

Establishment of a Rapid Detection System for ISG20-Dependent SARS-CoV-2 Subreplicon RNA Degradation Induced by Interferon-α.

Inhaled nebulized interferon (IFN)-α and IFN-ß have been shown to be effective in the management of coronavirus disease 2019 (COVID-19). We aimed to construct a virus-free rapid detection system for high-throughput screening of IFN-like compounds that induce viral RNA degradation and suppress the replication of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). We prepared a SARS-CoV-2 subreplicon RNA expression vector which contained the SARS-CoV-2 5'-UTR, the partial sequence of ORF1a, luciferase, nucleocapsid, ORF10, and 3'-UTR under the control of the cytomegalovirus promoter. The expression vector was transfected into Calu-3 cells and treated with IFN-α and the IFNAR2 agonist CDM-3008 (RO8191) for 3 days. SARS-CoV-2 subreplicon RNA degradation was subsequently evaluated based on luciferase levels. IFN-α and CDM-3008 suppressed SARS-CoV-2 subreplicon RNA in a dose-dependent manner, with IC50 values of 193 IU/mL and 2.54 µM, respectively. HeLa cells stably expressing SARS-CoV-2 subreplicon RNA were prepared and treated with the IFN-α and pan-JAK inhibitor Pyridone 6 or siRNA-targeting ISG20. IFN-α activity was canceled with Pyridone 6. The knockdown of ISG20 partially canceled IFN-α activity. Collectively, we constructed a virus-free rapid detection system to measure SARS-CoV-2 RNA suppression. Our data suggest that the SARS-CoV-2 subreplicon RNA was degraded by IFN-α-induced ISG20 exonuclease activity.

New Drugs 2021, Part 2.

ABSTRACT: The second of a two-part series, this article describes eight recently approved drugs, including the first drug approved for the treatment of SARS-CoV-2, a first-in-class HIV attachment inhibitor, and a new intravenous injection indicated for the treatment of acute pain in adults for whom other treatments are ineffective.

Potential of NO donor furoxan as SARS-CoV-2 main protease (Mpro) inhibitors: in silico analysis.

The sharp spurt in positive cases of novel coronavirus-19 (SARS-CoV-2) worldwide has created a big threat to human. In view to expedite new drug leads for COVID-19, Main Proteases (Mpro) of novel Coronavirus (SARS-CoV-2) has emerged as a crucial target for this virus. Nitric oxide (NO) inhibits the replication cycle of SARS-CoV. Inhalation of nitric oxide is used in the treatment of severe acute respiratory syndrome. Herein, we evaluated the phenyl furoxan, a well-known exogenous NO donor to identify the possible potent inhibitors through in silico studies such as molecular docking as per target analysis for candidates bound to substrate binding pocket of SARS-COV-2 Mpro. Molecular dynamics (MD) simulations of most stable docked complexes (Mpro-22 and Mpro-26) helped to confirm the notable conformational stability of these docked complexes under dynamic state. Furthermore, Molecular mechanics Poisson-Boltzmann surface area (MM-PBSA) calculations revealed energetic contributions of key residues of Mpro in binding with potent furoxan derivatives 22, 26. In the present study to validate the molecular docking, MD simulation and MM-PBSA results, crystal structure of Mpro bound to experimentally known inhibitor X77 was used as control and the obtained results are presented herein. We envisaged that spiro-isoquinolino-piperidine-furoxan moieties can be used as effective ligand for SARS-CoV-2 Mpro inhibition due to the presence of key isoquinolino-piperidine skeleton with additional NO effect.Communicated by Ramaswamy H. Sarma.

Potent toxic effects of Taroxaz-104 on the replication of SARS-CoV-2 particles.

Polyphenolics and 1,3,4-oxadiazoles are two of the most potent bioactive classes of compounds in medicinal chemistry, since both are known for their diverse pharmacological activities in humans. One of their prominent activities is the antimicrobial/antiviral activities, which are much apparent when the key functional structural moieties of both of them meet into the same compounds. The current COVID-19 pandemic motivated us to computationally screen and evaluate our library of previously-synthesized 2-(3,4,5-trihydroxyphenyl)-1,3,4-oxadiazoles against the major SARS-CoV-2 protein targets. Interestingly, few ligands showed promising low binding free energies (potent inhibitory interactions/affinities) with the active sites of some coronaviral-2 enzymes, specially the RNA-dependent RNA polymerase (nCoV-RdRp). One of them was 5,5'-{5,5'-[(1R,2R)-1,2-dihydroxyethane-1,2-diyl]bis(1,3,4-oxadiazole-5,2-diyl)}dibenzene-1,2,3-triol (Taroxaz-104), which showed significantly low binding energies (-10.60 and -9.10 kcal/mol) with nCoV-RdRp-RNA and nCoV-RdRp alone, respectively. These binding energies are even considerably lower than those of remdesivir potent active metabolite GS-443902 (which showed -9.20 and -7.90 kcal/mol with the same targets, respectively). Further computational molecular investigation revealed that Taroxaz-104 molecule strongly inhibits one of the potential active sites of nCoV-RdRp (the one with which GS-443902 molecule mainly interacts), since it interacts with at least seven major active amino acid residues of its predicted pocket. The successful repurposing of Taroxaz-104 has been achieved after the promising results of the anti-COVID-19 biological assay were obtained, as the data showed that Taroxaz-104 exhibited very significant anti-COVID-19 activities (anti-SARS-CoV-2 EC50 = 0.42 µM) with interesting effectiveness against the new strains/variants of SARS-CoV-2. Further investigations for the development of Taroxaz-104 and its coming polyphenolic 2,5-disubstituted-1,3,4-oxadiazole derivatives as anti-COVID-19 drugs, through in vivo bioevaluations and clinical trials research, are urgently needed.

CoViTris2020 and ChloViD2020: a striking new hope in COVID-19 therapy.

Designing anticoronavirus disease 2019 (anti-COVID-19) agents is the primary concern of medicinal chemists/drug designers nowadays. Repurposing of known active compounds against the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a new effective and time-saving trend in anti-COVID-19 drug discovery. Thorough inhibition of the coronaviral-2 proteins (i.e., multitarget inhibition) is a possible powerful favorable strategy for developing effectively potent drugs for COVID-19. In this new research study, I succeeded to repurpose the two antioxidant polyhydroxy-1,3,4-oxadiazole compounds CoViTris2020 and ChloViD2020 as the first multitarget coronaviral protein blockers with extremely higher potencies (reach about 65 and 304 times, for CoViTris2020, and 20 and 93 times, for ChloViD2020, more potent than remdesivir and favipiravir, respectively). These two 2,5-disubstituted-1,3,4-oxadiazoles were computationally studied (through molecular docking in almost all SARS-CoV-2 proteins) and biologically assessed (through a newly established robust in vitro anti-COVID-19 assay) for their anticoronaviral-2 bioactivities. The data obtained from the docking investigation showed that both ligands promisingly exhibited very strong inhibitory binding affinities with almost all docked enzymes (e.g., they displayed extremely lower binding energies of - 12.00 and - 9.60 kcal/mol, respectively, with the SARS-CoV-2 RNA-dependent RNA polymerase "RdRp"). The results of the biological assay revealed that CoViTris2020 and ChloViD2020 significantly displayed very high anti-COVID-19 activities (anti-SARS-CoV-2 EC50 = 0.31 and 1.01 µM, respectively). Further in vivo/clinical studies for the development of CoViTris2020 and ChloViD2020 as anti-COVID-19 medications are required. In brief, the ascent of CoViTris2020 and ChloViD2020 as the two lead members of the novel family of anti-COVID-19 polyphenolic 2,5-disubstituted-1,3,4-oxadiazole derivatives represents a promising hope in COVID-19 therapy. CoViTris2020 and ChloViD2020 inhibit SARS-CoV-2 life cycle with surprising EC50 values of 0.31 and 1.01 µM, respectively. CoViTris2020 strongly inhibits coronaviral-2 RdRp with exceptionally lower inhibitory binding energy of - 12.00 kcal/mol.

Battling COVID-19 Pandemic: Sphingosine-1-Phosphate Analogs as an Adjunctive Therapy?

With the sudden outbreak of COVID-19 patient worldwide and associated mortality, it is critical to come up with an effective treatment against SARS-CoV-2. Studies suggest that mortality due to COVID 19 is mainly attributed to the hyper inflammatory response leading to cytokine storm and ARDS in infected patients. Sphingosine-1-phosphate receptor 1 (S1PR1) analogs, AAL-R and RP-002, have earlier provided in-vivo protection from the pathophysiological response during H1N1 influenza infection and improved mortality. Recently, it was shown that the treatment with sphingosine-1-phosphate receptor 1 analog, CYM5442, resulted in the significant dampening of the immune response upon H1N1 challenge in mice and improved survival of H1N1 infected mice in combination with an antiviral drug, oseltamivir. Hence, here we suggest to investigate the possible utility of using S1P analogs to treat COVID-19.