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Smith TG, Gigante CM, Wynn NT, Matheny A, Davidson W, Yang Y, Condori RE, O'Connell K, Kovar L, Williams TL, Yu YC, Petersen BW, Baird N, Lowe D, Li Y, Satheshkumar PS, Hutson CL. Tecovirimat Resistance in Mpox Patients, United States, 2022-2023. Emerg Infect Dis 2023; 29:2426-2432. [PMID: 37856204 PMCID: PMC10683829 DOI: 10.3201/eid2912.231146] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2023] Open
Abstract
During the 2022 multinational outbreak of monkeypox virus (MPXV) infection, the antiviral drug tecovirimat (TPOXX; SIGA Technologies, Inc., https://www.siga.com) was deployed in the United States on a large scale for the first time. The MPXV F13L gene homologue encodes the target of tecovirimat, and single amino acid changes in F13 are known to cause resistance to tecovirimat. Genomic sequencing identified 11 mutations previously reported to cause resistance, along with 13 novel mutations. Resistant phenotype was determined using a viral cytopathic effect assay. We tested 124 isolates from 68 patients; 96 isolates from 46 patients were found to have a resistant phenotype. Most resistant isolates were associated with severely immunocompromised mpox patients on multiple courses of tecovirimat treatment, whereas most isolates identified by routine surveillance of patients not treated with tecovirimat remained sensitive. The frequency of resistant viruses remains relatively low (<1%) compared with the total number of patients treated with tecovirimat.
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Grosenbach DW, Russo AT, Blum ED, Hruby DE. Emerging pharmacological strategies for treating and preventing mpox. Expert Rev Clin Pharmacol 2023; 16:843-854. [PMID: 37592723 DOI: 10.1080/17512433.2023.2249820] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2023] [Revised: 08/10/2023] [Accepted: 08/16/2023] [Indexed: 08/19/2023]
Abstract
INTRODUCTION Since May 2022, there have been nearly 87,000 documented cases of mpox worldwide, with 119 deaths. Pharmacological interventions for mpox include the MVA-BN smallpox vaccine, tecovirimat, cidofovir, its pro-drug brincidofovir, and vaccinia immune globulin intravenous (VIGIV). AREAS COVERED The literature search and information gathering for this review included the PubMed database focusing on mpox and monkeypox, in combination with tecovirimat, brincidofovir, cidofovir, VIGIV, and smallpox vaccine. WHO.int, CDC.gov, FDA.gov, and ClinicalTrials.gov websites were accessed for the most recent information on the mpox outbreak. Mechanisms for deployment and access to treatment including expanded access, emergency use, and clinical trials will be discussed. Treatment outcomes with safety data will be presented. EXPERT OPINION The vaccine as a preventive measure, along with numerous treatment options, largely controlled the outbreak, although deployment of each could be improved upon to hasten and broaden access. More widespread coverage by the vaccine is necessary to prevent future resurgence of mpox. Tecovirimat has emerged as a safe frontline treatment for mpox, while brincidofovir use has been limited by safety concerns. VIGIV and cidofovir should be reserved for the most severe cases in which other options are not fully effective.
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Russo AT, Grosenbach DW, Honeychurch KM, Long PG, Hruby DE. Overview of the regulatory approval of tecovirimat intravenous formulation for treatment of smallpox: potential impact on smallpox outbreak response capabilities, and future tecovirimat development potential. Expert Rev Anti Infect Ther 2023; 21:235-242. [PMID: 36728515 PMCID: PMC10054055 DOI: 10.1080/14787210.2023.2170350] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2022] [Accepted: 01/16/2023] [Indexed: 02/03/2023]
Abstract
INTRODUCTION Tecovirimat oral capsule formulation is approved in the US and Canada for treatment of smallpox and in the United Kingdom (UK) and European Union (EU) for treatment of multiple human orthopoxvirus diseases, including mpox. Smallpox is considered a serious threat, and there is currently an unprecedented global mpox outbreak. AREAS COVERED A brief summary of the threat of smallpox, the threat of increasing mpox spread in endemic regions, and the unprecedented emergence of mpox into non-endemic regions is presented. The tecovirimat intravenous formulation clinical development program leading to USFDA approval for smallpox treatment is discussed. EXPERT OPINION As of January 2023 tecovirimat is approved to treat mpox in the UK and EU. However, published clinical trial data evaluating tecovirimat efficacy and safety in mpox patients is pending. Increasing global prevalence of mpox highlights the potential benefits of a well-characterized, effective, and safe antiviral treatment for mpox infection. Ongoing trials in mpox patients may provide results supporting the use of tecovirimat to treat this disease. USFDA approval of tecovirimat for post-exposure prophylaxis in the event of a smallpox release, and the development of pediatric liquid formulations for patients under 13 kg, could provide additional public health benefits.
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Oleinik GA, Koval VV, Usova SV, Shishkina LN, Chernonosov AA. Development and Validation of a Method of Liquid Chromatography Coupled with Tandem Mass Spectrometry for Quantification of ST-246 (Tecovirimat) in Human Plasma. Molecules 2022; 27. [PMID: 35684513 DOI: 10.3390/molecules27113577] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2022] [Revised: 05/25/2022] [Accepted: 05/27/2022] [Indexed: 01/20/2023] Open
Abstract
The aim of this work was to develop and validate a sensitive and robust method of liquid chromatography coupled with tandem mass spectrometry to quantitate ST-246 (tecovirimat) in plasma using an internal standard (2-hydroxy-N-{3,5-dioxo-4-azatetracyclo [5.3.2.02.6.08.10]dodec-11-en-4-yl}-5-methylbenzamide). The method was validated in negative multiple reaction monitoring mode following recommendations of the European Medicines Agency for the validation of bioanalytical methods. The calibration curve for the analyte was linear in the 10−2500 ng/mL range with determination coefficient R2 > 0.99. Intra- and inter-day accuracy and precision for three concentrations of quality control were <15%. Testing of long-term stability of ST-246 (tecovirimat) in plasma showed no degradation at −20 °C for at least 3 months. The method was applied to a clinical assay of a new antipoxvirus compound, NIOCH-14. Thus, the proposed method is suitable for therapeutic drug monitoring of ST-246 (tecovirimat) itself and of NIOCH-14 as its metabolic precursor.
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Zhang Z, Fu S, Wang F, Yang C, Wang L, Yang M, Zhang W, Zhong W, Zhuang X. A PBPK Model of Ternary Cyclodextrin Complex of ST-246 Was Built to Achieve a Reasonable IV Infusion Regimen for the Treatment of Human Severe Smallpox. Front Pharmacol 2022; 13:836356. [PMID: 35370741 PMCID: PMC8966223 DOI: 10.3389/fphar.2022.836356] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2021] [Accepted: 02/08/2022] [Indexed: 11/17/2022] Open
Abstract
ST-246 is an oral drug against pathogenic orthopoxvirus infections. An intravenous formulation is required for some critical patients. A ternary complex of ST-246/meglumine/hydroxypropyl-β-cyclodextrin with well-improved solubility was successfully developed in our institute. The aim of this study was to achieve a reasonable intravenous infusion regimen of this novel formulation by a robust PBPK model based on preclinical pharmacokinetic studies. The pharmacokinetics of ST-246 after intravenous injection at different doses in rats, dogs, and monkeys were conducted to obtain clearances. The clearance of humans was generated by using the allometric scaling approach. Tissue distribution of ST-246 was conducted in rats to obtain tissue partition coefficients (Kp). The PBPK model of the rat was first built using in vivo clearance and Kp combined with in vitro physicochemical properties, unbound fraction, and cyclodextrin effect parameters of ST-246. Then the PBPK model was transferred to a dog and monkey and validated simultaneously. Finally, pharmacokinetic profiles after IV infusion at different dosages utilizing the human PBPK model were compared to the observed oral PK profile of ST-246 at therapeutic dosage (600 mg). The mechanistic PBPK model described the animal PK behaviors of ST-246 via intravenous injection and infusion with fold errors within 1.2. It appeared that 6h-IV infusion at 5 mg/kg BID produced similar Cmax and AUC as oral administration at 600 mg. A PBPK model of ST-246 was built to achieve a reasonable regimen of IV infusion for the treatment of severe smallpox, which will facilitate the clinical translation of this novel formulation.
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Affiliation(s)
- Zhiwei Zhang
- State Key Laboratory of Toxicology and Medical Countermeasures, Beijing Institute of Pharmacology and Toxicology, Beijing, China
| | - Shuang Fu
- State Key Laboratory of Toxicology and Medical Countermeasures, Beijing Institute of Pharmacology and Toxicology, Beijing, China
| | - Furun Wang
- State Key Laboratory of Toxicology and Medical Countermeasures, Beijing Institute of Pharmacology and Toxicology, Beijing, China
| | - Chunmiao Yang
- State Key Laboratory of Toxicology and Medical Countermeasures, Beijing Institute of Pharmacology and Toxicology, Beijing, China
| | - Lingchao Wang
- State Key Laboratory of Toxicology and Medical Countermeasures, Beijing Institute of Pharmacology and Toxicology, Beijing, China
| | - Meiyan Yang
- State Key Laboratory of Toxicology and Medical Countermeasures, Beijing Institute of Pharmacology and Toxicology, Beijing, China
| | - Wenpeng Zhang
- State Key Laboratory of Toxicology and Medical Countermeasures, Beijing Institute of Pharmacology and Toxicology, Beijing, China
| | - Wu Zhong
- State Key Laboratory of Toxicology and Medical Countermeasures, Beijing Institute of Pharmacology and Toxicology, Beijing, China
| | - Xiaomei Zhuang
- State Key Laboratory of Toxicology and Medical Countermeasures, Beijing Institute of Pharmacology and Toxicology, Beijing, China
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Lindholm DA, Fisher RD, Montgomery JR, Davidson W, Yu PA, Yu YC, Burgado J, Wilkins K, Petersen BW, Okulicz JF. Preemptive Tecovirimat Use in an Active Duty Service Member Who Presented With Acute Myeloid Leukemia After Smallpox Vaccination. Clin Infect Dis 2020; 69:2205-2207. [PMID: 30959520 DOI: 10.1093/cid/ciz286] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2018] [Accepted: 04/03/2019] [Indexed: 11/13/2022] Open
Abstract
Smallpox vaccine is contraindicated in immunosuppression due to increased risk for adverse reactions (eg, progressive vaccinia). We describe the first-ever use of tecovirimat as a preemptive vaccinia virus treatment strategy during induction chemotherapy in an active duty service member who presented with acute leukemia and inadvertent autoinoculation after smallpox vaccination.
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Affiliation(s)
- David A Lindholm
- Infectious Disease Service, Joint Base San Antonio-Fort Sam Houston, Texas.,Department of Medicine, San Antonio Military Medical Center, Joint Base San Antonio-Fort Sam Houston, Texas
| | - Raymond D Fisher
- Department of Medicine, San Antonio Military Medical Center, Joint Base San Antonio-Fort Sam Houston, Texas
| | - Jay R Montgomery
- Immunization Healthcare Branch, Defense Health Agency, Falls Church, Virginia
| | - Whitni Davidson
- Division of High-Consequence Pathogens and Pathology (Poxvirus and Rabies Branch)
| | - Patricia A Yu
- Division of Preparedness and Emerging Infections (Regulatory Affairs), National Center for Emerging and Zoonotic Infectious Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia
| | - Yon C Yu
- Division of Preparedness and Emerging Infections (Regulatory Affairs), National Center for Emerging and Zoonotic Infectious Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia
| | - Jillybeth Burgado
- Division of High-Consequence Pathogens and Pathology (Poxvirus and Rabies Branch)
| | - Kimberly Wilkins
- Division of High-Consequence Pathogens and Pathology (Poxvirus and Rabies Branch)
| | - Brett W Petersen
- Division of High-Consequence Pathogens and Pathology (Poxvirus and Rabies Branch)
| | - Jason F Okulicz
- Infectious Disease Service, Joint Base San Antonio-Fort Sam Houston, Texas.,Department of Medicine, San Antonio Military Medical Center, Joint Base San Antonio-Fort Sam Houston, Texas
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Russo AT, Grosenbach DW, Chinsangaram J, Honeychurch KM, Long PG, Lovejoy C, Maiti B, Meara I, Hruby DE. An overview of tecovirimat for smallpox treatment and expanded anti-orthopoxvirus applications. Expert Rev Anti Infect Ther 2020; 19:331-344. [PMID: 32882158 PMCID: PMC9491074 DOI: 10.1080/14787210.2020.1819791] [Citation(s) in RCA: 82] [Impact Index Per Article: 20.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Introduction Tecovirimat (TPOXX®; ST-246) was approved for the treatment of symptomatic smallpox by the USFDA in July of 2018 and has been stockpiled by the US government for use in a smallpox outbreak. While there has not been a reported case of smallpox since 1978 it is still considered a serious bioterrorism threat. Areas covered A brief history of smallpox from its proposed origins as a human disease through its eradication in the late 20th century is presented. The current smallpox threat and the current public health response plans are described. The discovery, and development of tecovirimat through NDA submission and subsequent approval for treatment of smallpox are discussed. Google Scholar and PubMed were searched over all available dates for relevant publications. Expert opinion Approval of tecovirimat to treat smallpox represents an important milestone in biosecurity preparedness. Incorporating tecovirimat into the CDC smallpox response plan, development of pediatric liquid and intravenous formulations, and approval for post-exposure prophylaxis would provide additional health security benefit. Tecovirimat shows broad efficacy against orthopoxviruses in vitro and in vivo and could be developed for use against emerging orthopoxvirus diseases such as monkeypox, vaccination-associated adverse events, and side effects of vaccinia oncolytic virus therapy.
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Affiliation(s)
- Andrew T Russo
- Poxvirus Research Group, SIGA Technologies, Inc, Corvallis, OR, USA
| | | | | | | | - Paul G Long
- Regulatory Affairs, SIGA Technologies, Inc, Corvallis, OR, USA
| | - Candace Lovejoy
- Program Management, SIGA Technologies, Inc, Corvallis, OR, USA
| | - Biswajit Maiti
- Drug Metabolism & Pharmacokinetics, SIGA Technologies, Inc, Corvallis, OR, USA
| | - Ingrid Meara
- Clinical Research, SIGA Technologies, Inc, Corvallis, OR, USA
| | - Dennis E Hruby
- Chief Scientific Officer, SIGA Technologies, Inc, Corvallis, OR, USA
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Priyamvada L, Alabi P, Leon A, Kumar A, Sambhara S, Olson VA, Sello JK, Satheshkumar PS. Discovery of Retro-1 Analogs Exhibiting Enhanced Anti-vaccinia Virus Activity. Front Microbiol 2020; 11:603. [PMID: 32390964 PMCID: PMC7190985 DOI: 10.3389/fmicb.2020.00603] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2019] [Accepted: 03/18/2020] [Indexed: 11/13/2022] Open
Abstract
Orthopoxviruses (OPXVs) are an increasing threat to human health due to the growing population of OPXV-naive individuals after the discontinuation of routine smallpox vaccination. Antiviral drugs that are effective as postexposure treatments against variola virus (the causative agent of smallpox) or other OPXVs are critical in the event of an OPXV outbreak or exposure. The only US Food and Drug Administration-approved drug to treat smallpox, Tecovirimat (ST-246), exerts its antiviral effect by inhibiting extracellular virus (EV) formation, thereby preventing cell-cell and long-distance spread. We and others have previously demonstrated that host Golgi-associated retrograde proteins play an important role in monkeypox virus (MPXV) and vaccinia virus (VACV) EV formation. Inhibition of the retrograde pathway by small molecules such as Retro-2 has been shown to decrease VACV infection in vitro and to a lesser extent in vivo. To identify more potent inhibitors of the retrograde pathway, we screened a large panel of compounds containing a benzodiazepine scaffold like that of Retro-1, against VACV infection. We found that a subset of these compounds displayed better anti-VACV activity, causing a reduction in EV particle formation and viral spread compared to Retro-1. PA104 emerged as the most potent analog, inhibiting 90% viral spread at 1.3 μM with a high selectivity index. In addition, PA104 strongly inhibited two distinct ST-246-resistant viruses, demonstrating its potential benefit for use in combination therapy with ST-246. These data and further characterizations of the specific protein targets and in vivo efficacy of PA104 may have important implications for the design of effective antivirals against OPXV.
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Affiliation(s)
- Lalita Priyamvada
- Poxvirus and Rabies Branch, Centers for Disease Control and Prevention, Atlanta, GA, United States
| | - Philip Alabi
- Department of Chemistry, Brown University, Providence, RI, United States
| | - Andres Leon
- Department of Chemistry, Brown University, Providence, RI, United States
| | - Amrita Kumar
- Immunology and Pathogenesis Branch, Influenza Division, Centers for Disease Control and Prevention, Atlanta, GA, United States
| | - Suryaprakash Sambhara
- Immunology and Pathogenesis Branch, Influenza Division, Centers for Disease Control and Prevention, Atlanta, GA, United States
| | - Victoria A Olson
- Poxvirus and Rabies Branch, Centers for Disease Control and Prevention, Atlanta, GA, United States
| | - Jason K Sello
- Department of Chemistry, Brown University, Providence, RI, United States
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Pires MA, Rodrigues NFS, de Oliveira DB, de Assis FL, Costa GB, Kroon EG, Mota BEF. In vitro susceptibility to ST-246 and Cidofovir corroborates the phylogenetic separation of Brazilian Vaccinia virus into two clades. Antiviral Res 2018; 152:36-44. [PMID: 29427676 DOI: 10.1016/j.antiviral.2018.02.005] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2017] [Revised: 01/29/2018] [Accepted: 02/05/2018] [Indexed: 01/01/2023]
Abstract
The Orthopoxvirus (OPV) genus of the Poxviridae family contains several human pathogens, including Vaccinia virus (VACV), which have been implicating in outbreaks of a zoonotic disease called Bovine Vaccinia in Brazil. So far, no approved treatment exists for OPV infections, but ST-246 and Cidofovir (CDV) are now in clinical development. Therefore, the objective of this work was to evaluate the susceptibility of five strains of Brazilian VACV (Br-VACV) to ST-246 and Cidofovir. The susceptibility of these strains to both drugs was evaluated by plaque reduction assay, extracellular virus's quantification in the presence of ST-246 and one-step growth curve in cells treated with CDV. Besides that, the ORFs F13L and E9L were sequenced for searching of polymorphisms associated with drug resistance. The effective concentration of 50% (EC50) from both drugs varies significantly for different strains (from 0.0054 to 0.051 μM for ST-246 and from 27.14 to 61.23 μM for CDV). ST-246 strongly inhibits the production of extracellular virus for all isolates in concentrations as low as 0.1 μM and it was observed a relevant decrease of progeny production for all Br-VACV after CDV treatment. Sequencing of the F13L and E9L ORFs showed that Br-VACV do not present the polymorphism(s) associated with resistance to ST-246 and CDV. Taken together, our results showed that ST-246 and CDV are effective against diverse, wild VACV strains and that the susceptibility of Br-VACV to these drugs mirrored the phylogenetic split of these isolates into two groups. Thus, both ST-246 and CDV are of great interest as compounds to treat individuals during Bovine Vaccinia outbreaks in Brazil.
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Affiliation(s)
- Mariana A Pires
- Laboratório de Microbiologia Clínica, Departamento de Análises Clínicas e Toxicológicas, Faculdade de Farmácia, Universidade Federal de Minas Gerais (UFMG), Avenida Antônio Carlos, 6627, CEP 31270-901, Belo Horizonte, Brazil
| | - Nathália F S Rodrigues
- Laboratório de Microbiologia Clínica, Departamento de Análises Clínicas e Toxicológicas, Faculdade de Farmácia, Universidade Federal de Minas Gerais (UFMG), Avenida Antônio Carlos, 6627, CEP 31270-901, Belo Horizonte, Brazil
| | - Danilo B de Oliveira
- Laboratório de Vírus, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais (UFMG), Avenida Antônio Carlos, 6627, CEP 31270-901, Belo Horizonte, Brazil
| | - Felipe L de Assis
- Laboratório de Vírus, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais (UFMG), Avenida Antônio Carlos, 6627, CEP 31270-901, Belo Horizonte, Brazil
| | - Galileu B Costa
- Laboratório de Vírus, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais (UFMG), Avenida Antônio Carlos, 6627, CEP 31270-901, Belo Horizonte, Brazil
| | - Erna G Kroon
- Laboratório de Vírus, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais (UFMG), Avenida Antônio Carlos, 6627, CEP 31270-901, Belo Horizonte, Brazil
| | - Bruno E F Mota
- Laboratório de Microbiologia Clínica, Departamento de Análises Clínicas e Toxicológicas, Faculdade de Farmácia, Universidade Federal de Minas Gerais (UFMG), Avenida Antônio Carlos, 6627, CEP 31270-901, Belo Horizonte, Brazil.
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Abstract
Prominent in the current stage of antiviral drug development are: (i) for human immunodeficiency virus (HIV), the use of fixed-dose combinations (FDCs), the most recent example being Stribild(TM); (ii) for hepatitis C virus (HCV), the pleiade of direct-acting antivirals (DAAs) that should be formulated in the most appropriate combinations so as to obtain a cure of the infection; (iii)-(v) new strategies (i.e., AIC316, AIC246, and FV-100) for the treatment of herpesvirus infections: herpes simplex virus (HSV), cytomegalovirus (CMV), and varicella-zoster virus (VZV), respectively; (vi) the role of a new tenofovir prodrug, tenofovir alafenamide (TAF) (GS-7340) for the treatment of HIV infections; (vii) the potential use of poxvirus inhibitors (CMX001 and ST-246); (viii) the usefulness of new influenza virus inhibitors (peramivir and laninamivir octanoate); (ix) the position of the hepatitis B virus (HBV) inhibitors [lamivudine, adefovir dipivoxil, entecavir, telbivudine, and tenofovir disoproxil fumarate (TDF)]; and (x) the potential of new compounds such as FGI-103, FGI-104, FGI-106, dUY11, and LJ-001 for the treatment of filoviruses (i.e., Ebola). Whereas for HIV and HCV therapy is aimed at multiple-drug combinations, for all other viruses, HSV, CMV, VZV, pox, influenza, HBV, and filoviruses, current strategies are based on the use of single compounds.
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Affiliation(s)
- Erik De Clercq
- Rega Institute for Medical Research, KU Leuven, B-3000, Leuven, Belgium.
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Jordan R, Leeds JM, Tyavanagimatt S, Hruby DE. Development of ST-246® for Treatment of Poxvirus Infections. Viruses 2010; 2:2409-35. [PMID: 21994624 DOI: 10.3390/v2112409] [Citation(s) in RCA: 68] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2010] [Revised: 10/26/2010] [Accepted: 10/26/2010] [Indexed: 12/26/2022] Open
Abstract
ST-246 (Tecovirimat) is a small synthetic antiviral compound being developed to treat pathogenic orthopoxvirus infections of humans. The compound was discovered as part of a high throughput screen designed to identify inhibitors of vaccinia virus-induced cytopathic effects. The antiviral activity is specific for orthopoxviruses and the compound does not inhibit the replication of other RNA- and DNA-containing viruses or inhibit cell proliferation at concentrations of compound that are antiviral. ST-246 targets vaccinia virus p37, a viral protein required for envelopment and secretion of extracellular forms of virus. The compound is orally bioavailable and protects multiple animal species from lethal orthopoxvirus challenge. Preclinical safety pharmacology studies in mice and non-human primates indicate that ST-246 is readily absorbed by the oral route and well tolerated with the no observable adverse effect level (NOAEL) in mice measured at 2000 mg/kg and the no observable effect level (NOEL) in non-human primates measured at 300 mg/kg. Drug substance and drug product processes have been developed and commercial scale batches have been produced using Good Manufacturing Processes (GMP). Human phase I clinical trials have shown that ST-246 is safe and well tolerated in healthy human volunteers. Based on the results of the clinical evaluation, once a day dosing should provide plasma drug exposure in the range predicted to be antiviral based on data from efficacy studies in animal models of orthopoxvirus disease. These data support the use of ST-246 as a therapeutic to treat pathogenic orthopoxvirus infections of humans.
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Parker S, Siddiqui AM, Painter G, Schriewer J, Buller RM. Ectromelia virus infections of mice as a model to support the licensure of anti-orthopoxvirus therapeutics. Viruses 2010; 2:1918-1932. [PMID: 21994714 PMCID: PMC3185751 DOI: 10.3390/v2091918] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2010] [Revised: 08/30/2010] [Accepted: 08/31/2010] [Indexed: 12/02/2022] Open
Abstract
The absence of herd immunity to orthopoxviruses and the concern that variola or monkeypox viruses could be used for bioterroristic activities has stimulated the development of therapeutics and safer prophylactics. One major limitation in this process is the lack of accessible human orthopoxvirus infections for clinical efficacy trials; however, drug licensure can be based on orthopoxvirus animal challenge models as described in the "Animal Efficacy Rule". One such challenge model uses ectromelia virus, an orthopoxvirus, whose natural host is the mouse and is the etiological agent of mousepox. The genetic similarity of ectromelia virus to variola and monkeypox viruses, the common features of the resulting disease, and the convenience of the mouse as a laboratory animal underscores its utility in the study of orthopoxvirus pathogenesis and in the development of therapeutics and prophylactics. In this review we outline how mousepox has been used as a model for smallpox. We also discuss mousepox in the context of mouse strain, route of infection, infectious dose, disease progression, and recovery from infection.
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Affiliation(s)
- Scott Parker
- Department of Molecular Microbiology and Immunology, Saint Louis University School of Medicine, 1100 S. Grand Blvd., St. Louis, MO, 63104, USA; E-Mails: (S.P.); (A.M.S.); (J.S.)
| | - Akbar M. Siddiqui
- Department of Molecular Microbiology and Immunology, Saint Louis University School of Medicine, 1100 S. Grand Blvd., St. Louis, MO, 63104, USA; E-Mails: (S.P.); (A.M.S.); (J.S.)
| | - George Painter
- Chimerix Inc., 2505 Meridian Park Way, Suite 340, Durham, NC, 27713, USA; E-Mail:
| | - Jill Schriewer
- Department of Molecular Microbiology and Immunology, Saint Louis University School of Medicine, 1100 S. Grand Blvd., St. Louis, MO, 63104, USA; E-Mails: (S.P.); (A.M.S.); (J.S.)
| | - R. Mark Buller
- Department of Molecular Microbiology and Immunology, Saint Louis University School of Medicine, 1100 S. Grand Blvd., St. Louis, MO, 63104, USA; E-Mails: (S.P.); (A.M.S.); (J.S.)
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Duraffour S, Andrei G, Snoeck R. [Novel therapeutic weapons against poxviruses]. Virologie (Montrouge) 2008; 12:323-338. [PMID: 36151678 DOI: 10.1684/vir.2011.12132] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
Poxviruses include several pathogens responsible for diseases recognized as important for human health, such as smallpox, monkeypox, orf and molluscum contagiosum. Smallpox, whose etiological agent is Variola virus, is a highly contagious disease which was eradicated last century. Today, the potential use of Variola virus in bioterrorism is real. Hence, efforts have been intensified for the selection of novel anti-poxvirus compounds. The increased understanding of the poxviral replication, the establishment of threedimensional cell cultures, as well as the validation of several animal models, have led to the discovery and the development of new and promising classes of compounds active against poxviruses. Cidofovir, an acyclic cytosine phosphonate analogue and hexadecylpropanediol-cidofovir (CMX001), one of its prodrug orally bioavailable, inhibit poxvirus replication in vitro, ex vivo and in vivo by targeting the viral DNA polymerase. Another compound, ST-246, inhibits a crucial step of the orthopoxvirus morphogenesis. Its antiviral activity has been demonstrated in several animal models, and its safety has been confirmed in healthy human volunteers following a phase I clinical trial. Recent developments made in vitro, ex vivo, in vivo and in humans, in terms of antiviral treatments available of poxvirus infections, are discussed in this review.
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Affiliation(s)
- S Duraffour
- Institut Rega, Section virologie et chimiothérapie, Minderbroedersstraat 10, 3000 Leuven, Belgique
| | - G Andrei
- Institut Rega, Section virologie et chimiothérapie, Minderbroedersstraat 10, 3000 Leuven, Belgique
| | - R Snoeck
- Institut Rega, Section virologie et chimiothérapie, Minderbroedersstraat 10, 3000 Leuven, Belgique
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