1
|
Kura K, Milton P, Hamley JID, Walker M, Bakajika DK, Kanza EM, Opoku NO, Howard H, Nigo MM, Asare S, Olipoh G, Attah SK, Mambandu GL, Kennedy KK, Kataliko K, Mumbere M, Halleux CM, Hopkins A, Kuesel AC, Kinrade S, Basáñez MG. Can mass drug administration of moxidectin accelerate onchocerciasis elimination in Africa? Philos Trans R Soc Lond B Biol Sci 2023; 378:20220277. [PMID: 37598705 PMCID: PMC10440165 DOI: 10.1098/rstb.2022.0277] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2022] [Accepted: 04/11/2023] [Indexed: 08/22/2023] Open
Abstract
Epidemiological and modelling studies suggest that elimination of Onchocerca volvulus transmission (EoT) throughout Africa may not be achievable with annual mass drug administration (MDA) of ivermectin alone, particularly in areas of high endemicity and vector density. Single-dose Phase II and III clinical trials demonstrated moxidectin's superiority over ivermectin for prolonged clearance of O. volvulus microfilariae. We used the stochastic, individual-based EPIONCHO-IBM model to compare the probabilities of reaching EoT between ivermectin and moxidectin MDA for a range of endemicity levels (30 to 70% baseline microfilarial prevalence), treatment frequencies (annual and biannual) and therapeutic coverage/adherence values (65 and 80% of total population, with, respectively, 5 and 1% of systematic non-adherence). EPIONCHO-IBM's projections indicate that biannual (six-monthly) moxidectin MDA can reduce by half the number of years necessary to achieve EoT in mesoendemic areas and might be the only strategy that can achieve EoT in hyperendemic areas. Data needed to improve modelling projections include (i) the effect of repeated annual and biannual moxidectin treatment; (ii) inter- and intra-individual variation in response to successive treatments with moxidectin or ivermectin; (iii) the effect of moxidectin and ivermectin treatment on L3 development into adult worms; and (iv) patterns of adherence to moxidectin and ivermectin MDA. This article is part of the theme issue 'Challenges in the fight against neglected tropical diseases: a decade from the London Declaration on NTDs'.
Collapse
Affiliation(s)
- Klodeta Kura
- London Centre for Neglected Tropical Disease Research, Department of Infectious Disease Epidemiology, School of Public Health, Imperial College London, London W2 1PG, UK
- MRC Centre for Global Infectious Disease Analysis, Department of Infectious Disease Epidemiology, School of Public Health, Imperial College London, London W2 1PG, UK
| | - Philip Milton
- London Centre for Neglected Tropical Disease Research, Department of Infectious Disease Epidemiology, School of Public Health, Imperial College London, London W2 1PG, UK
- MRC Centre for Global Infectious Disease Analysis, Department of Infectious Disease Epidemiology, School of Public Health, Imperial College London, London W2 1PG, UK
| | - Jonathan I. D. Hamley
- London Centre for Neglected Tropical Disease Research, Department of Infectious Disease Epidemiology, School of Public Health, Imperial College London, London W2 1PG, UK
- MRC Centre for Global Infectious Disease Analysis, Department of Infectious Disease Epidemiology, School of Public Health, Imperial College London, London W2 1PG, UK
| | - Martin Walker
- London Centre for Neglected Tropical Disease Research, Department of Infectious Disease Epidemiology, School of Public Health, Imperial College London, London W2 1PG, UK
- Department of Pathobiology and Population Sciences, Royal Veterinary College, Hatfield AL9 7TA, UK
| | - Didier K. Bakajika
- Expanded Special Project for Elimination of Neglected Tropical Diseases (ESPEN), African Regional Office of the World Health Organization (WHO/AFRO/ESPEN), Brazzaville, Democratic Republic of Congo
| | - Eric M. Kanza
- Programme Nationale de Lutte contre les Maladies Tropicales Négligées à Chimiothérapie Préventive (PNLMTN-CTP), Ministère de la Santé Publique, Kinshasa, Democratic Republic of the Congo
| | - Nicholas O. Opoku
- Department of Epidemiology and Biostatistics, School of Public Health, University of Health and Allied Sciences, Hohoe, Ghana
| | - Hayford Howard
- Liberia Institute for Biomedical Research (LIBR), Monrovia, Liberia
| | - Maurice M. Nigo
- Institut Supérieur des Techniques Médicales de Nyankunde, Bunia, Democratic Republic of the Congo
| | | | - George Olipoh
- Precious Minerals Marketing Company, National Assay Centre, Technical Department, Diamond House, Accra, GA-143-2548, Ghana
| | - Simon K. Attah
- Department of Medical Microbiology, University of Ghana Medical School, College of Health Sciences, Accra, Ghana
| | - Germain L. Mambandu
- Inspection Provinciale de la Santé de la Tshopo, Kisangani, Democratic Republic of the Congo
| | - Kambale Kasonia Kennedy
- Department of Clinical Research, London School of Hygiene and Tropical Medicine, London WC1E 7HT, UK
| | - Kambale Kataliko
- Centre de Santé CECA 20 de Mabakanga, Beni, Nord Kivu, Democratic Republic of the Congo
| | - Mupenzi Mumbere
- Medicines Development for Global Health, 18 Kavanagh Street, Southbank, Victoria 3006, Australia
| | - Christine M. Halleux
- UNICEF/UNDP/World Bank/WHO Special Programme for Research and Training in Tropical Diseases (TDR), World Health Organization, 1211 Geneva 27, Switzerland
| | - Adrian Hopkins
- Neglected and Disabling Diseases of Poverty Consultant, Gravesend, Kent DA11 OSL, UK
| | - Annette C. Kuesel
- UNICEF/UNDP/World Bank/WHO Special Programme for Research and Training in Tropical Diseases (TDR), World Health Organization, 1211 Geneva 27, Switzerland
| | - Sally Kinrade
- Medicines Development for Global Health, 18 Kavanagh Street, Southbank, Victoria 3006, Australia
| | - Maria-Gloria Basáñez
- London Centre for Neglected Tropical Disease Research, Department of Infectious Disease Epidemiology, School of Public Health, Imperial College London, London W2 1PG, UK
- MRC Centre for Global Infectious Disease Analysis, Department of Infectious Disease Epidemiology, School of Public Health, Imperial College London, London W2 1PG, UK
| |
Collapse
|
2
|
Pfarr KM, Krome AK, Al-Obaidi I, Batchelor H, Vaillant M, Hoerauf A, Opoku NO, Kuesel AC. The pipeline for drugs for control and elimination of neglected tropical diseases: 1. Anti-infective drugs for regulatory registration. Parasit Vectors 2023; 16:82. [PMID: 36859332 PMCID: PMC9979492 DOI: 10.1186/s13071-022-05581-4] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2022] [Accepted: 11/05/2022] [Indexed: 03/03/2023] Open
Abstract
The World Health Organization 'Ending the neglect to attain the Sustainable Development Goals: A road map for neglected tropical diseases 2021-2030' outlines the targets for control and elimination of neglected tropical diseases (NTDs). New drugs are needed to achieve some of them. We are providing an overview of the pipeline for new anti-infective drugs for regulatory registration and steps to effective use for NTD control and elimination. Considering drugs approved for an NTD by at least one stringent regulatory authority: fexinidazole, included in WHO guidelines for Trypanosoma brucei gambiense African trypanosomiasis, is in development for Chagas disease. Moxidectin, registered in 2018 for treatment of individuals ≥ 12 years old with onchocerciasis, is undergoing studies to extend the indication to 4-11-year-old children and obtain additional data to inform WHO and endemic countries' decisions on moxidectin inclusion in guidelines and policies. Moxidectin is also being evaluated for other NTDs. Considering drugs in at least Phase 2 clinical development, a submission is being prepared for registration of acoziborole as an oral treatment for first and second stage T.b. gambiense African trypanosomiasis. Bedaquiline, registered for tuberculosis, is being evaluated for multibacillary leprosy. Phase 2 studies of emodepside and flubentylosin in O. volvulus-infected individuals are ongoing; studies for Trichuris trichuria and hookworm are planned. A trial of fosravuconazole in Madurella mycetomatis-infected patients is ongoing. JNJ-64281802 is undergoing Phase 2 trials for reducing dengue viral load. Studies are ongoing or planned to evaluate oxantel pamoate for onchocerciasis and soil-transmitted helminths, including Trichuris, and oxfendazole for onchocerciasis, Fasciola hepatica, Taenia solium cysticercosis, Echinococcus granulosus and soil-transmitted helminths, including Trichuris. Additional steps from first registration to effective use for NTD control and elimination include country registrations, possibly additional studies to inform WHO guidelines and country policies, and implementation research to address barriers to effective use of new drugs. Relative to the number of people suffering from NTDs, the pipeline is small. Close collaboration and exchange of experience among all stakeholders developing drugs for NTDs may increase the probability that the current pipeline will translate into new drugs effectively implemented in affected countries.
Collapse
Affiliation(s)
- Kenneth M. Pfarr
- grid.15090.3d0000 0000 8786 803XInstitute of Medical Microbiology, Immunology and Parasitology, University Hospital Bonn, Bonn, Germany ,grid.452463.2German Center for Infection Research, Partner Site Bonn-Cologne, Bonn, Germany
| | - Anna K. Krome
- grid.10388.320000 0001 2240 3300Department of Pharmaceutical Technology and Biopharmaceutics, University of Bonn, Bonn, Germany
| | - Issraa Al-Obaidi
- grid.11984.350000000121138138Strathclyde Institute of Pharmacy and Biomedical Sciences, University of Strathclyde, Glasgow, UK
| | - Hannah Batchelor
- grid.11984.350000000121138138Strathclyde Institute of Pharmacy and Biomedical Sciences, University of Strathclyde, Glasgow, UK
| | - Michel Vaillant
- grid.451012.30000 0004 0621 531XCompetence Center for Methodology and Statistics, Luxembourg Institute of Health, Strassen, Grand Duchy of Luxembourg
| | - Achim Hoerauf
- grid.15090.3d0000 0000 8786 803XInstitute of Medical Microbiology, Immunology and Parasitology, University Hospital Bonn, Bonn, Germany ,grid.452463.2German Center for Infection Research, Partner Site Bonn-Cologne, Bonn, Germany
| | - Nicholas O. Opoku
- grid.449729.50000 0004 7707 5975Department of Epidemiology and Biostatistics School of Public Health, University of Health and Allied Sciences, Hohoe, Ghana
| | - Annette C. Kuesel
- UNICEF/UNDP/World Bank/WHO Special Programme for Research and Training in Tropical Diseases (WHO/TDR), World Health Organization, Geneva, Switzerland
| |
Collapse
|
3
|
Biamonte MA, Cantey PT, Coulibaly YI, Gass KM, Hamill LC, Hanna C, Lammie PJ, Kamgno J, Nutman TB, Oguttu DW, Sankara DP, Stolk WA, Unnasch TR. Onchocerciasis: Target product profiles of in vitro diagnostics to support onchocerciasis elimination mapping and mass drug administration stopping decisions. PLoS Negl Trop Dis 2022; 16:e0010682. [PMID: 35921329 PMCID: PMC9377578 DOI: 10.1371/journal.pntd.0010682] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2022] [Revised: 08/15/2022] [Accepted: 07/20/2022] [Indexed: 11/19/2022] Open
Abstract
In June 2021, the World Health Organization (WHO), recognizing the need for new diagnostics to support the control and elimination of onchocerciasis, published the target product profiles (TPPs) of new tests that would support the two most immediate needs: (a) mapping onchocerciasis in areas of low prevalence and (b) deciding when to stop mass drug administration programs. In both instances, the test should ideally detect an antigen specific for live, adult O. volvulus female worms. The preferred format is a field-deployable rapid test. For mapping, the test needs to be ≥ 60% sensitive and ≥ 99.8% specific, while to support stopping decisions, the test must be ≥ 89% sensitive and ≥ 99.8% specific. The requirement for extremely high specificity is dictated by the need to detect with sufficient statistical confidence the low seroprevalence threshold set by WHO. Surveys designed to detect a 1–2% prevalence of a given biomarker, as is the case here, cannot tolerate more than 0.2% of false-positives. Otherwise, the background noise would drown out the signal. It is recognized that reaching and demonstrating such a stringent specificity criterion will be challenging, but test developers can expect to be assisted by national governments and implementing partners for adequately powered field validation. River blindness, also known as onchocerciasis, affects 21 million people, predominantly in sub-Saharan Africa. For decades, the international community has fought this disease through mass drug administration (MDA) programs focused on controlling morbidity in areas of high prevalence. Now, as part of their 2021–2030 Roadmap for Neglected Tropical Diseases, the World Health Organization (WHO) has set an ambitious goal, shifting from controlling to eliminating onchocerciasis. This implies addressing areas of low infection prevalence. As a result, new diagnostics tools are required to identify and map areas of low onchocerciasis prevalence and to help decide where to initiate MDA. Similarly, new diagnostics are required to decide when the prevalence of onchocerciasis is sufficiently low to justify stopping MDA. A WHO-appointed independent panel, the Diagnostics Technical Advisory Group for Neglected Tropical Diseases, and its subgroup specific to onchocerciasis, have established the desired Target Product Profiles (TPPs) for such new tests. The TPPs were posted in June 2021 on the WHO website. This article describes the methodology used to produce the TPPs, with an emphasis on calculating the required sensitivity and specificity characteristics.
Collapse
Affiliation(s)
- Marco A. Biamonte
- Drugs & Diagnostics for Tropical Diseases, San Diego, California, United States of America
- * E-mail:
| | - Paul T. Cantey
- Division of Parasitic Diseases and Malaria, U.S. Centers for Disease Control and Prevention, Atlanta, Georgia, United States of America
| | - Yaya I. Coulibaly
- Mali International Center for Excellence in Research, Faculty of Medicine and Odonto-Stomatology, University of Sciences, Techniques and Technologies of Bamako, Bamako, Mali, Dermatology Hospital of Bamako, Bamako, Mali
| | - Katherine M. Gass
- Neglected Tropical Diseases Support Center, Task Force for Global Health, Decatur, Georgia, United States of America
| | | | - Christopher Hanna
- Global Project Partners, Oakland, California, United States of America
| | - Patrick J. Lammie
- Neglected Tropical Diseases Support Center, Task Force for Global Health, Decatur, Georgia, United States of America
| | - Joseph Kamgno
- Centre for Research on Filariasis and other Tropical Diseases, Yaoundé, Cameroon, Faculty of Medicine and Biomedical Sciences, University of Yaoundé I, Yaoundé, Cameroon
| | - Thomas B. Nutman
- Laboratory of Parasitic Diseases, National Institute of Allergy and Infectious Diseases, Bethesda, Maryland, United States of America
| | - David W. Oguttu
- Vector Control Division, Ministry of Health, Kampala, Uganda
| | - Dieudonné P. Sankara
- Department of Control of Neglected Tropical Diseases, World Health Organization, Geneva, Switzerland
| | - Wilma A. Stolk
- Department of Public Health, Erasmus MC, University Medical Center Rotterdam, Rotterdam, the Netherlands
| | - Thomas R. Unnasch
- Global Health Infectious Disease Research Program, University of South Florida, Tampa, Florida, United States of America
| |
Collapse
|
4
|
Gunderson EL, Bryant C, Bulman CA, Fischer C, Luo M, Vogel I, Lim KC, Jawahar S, Tricoche N, Voronin D, Corbo C, Ayiseh RB, Manfo FPT, Mbah GE, Cho-Ngwa F, Beerntsen B, Renslo AR, Lustigman S, Sakanari JA. Pyrvinium Pamoate and Structural Analogs Are Early Macrofilaricide Leads. Pharmaceuticals (Basel) 2022; 15:189. [PMID: 35215301 PMCID: PMC8880385 DOI: 10.3390/ph15020189] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2021] [Revised: 01/05/2022] [Accepted: 01/07/2022] [Indexed: 12/05/2022] Open
Abstract
Onchocerciasis and lymphatic filariasis are neglected tropical diseases caused by infection with filarial worms. Annual or biannual mass drug administration with microfilaricidal drugs that kill the microfilarial stages of the parasites has helped reduce infection rates and thus prevent transmission of both infections. However, success depends on high population coverage that is maintained for the duration of the adult worm's lifespan. Given that these filarial worms can live up to 14 years in their human hosts, a macrofilaricidal drug would vastly accelerate elimination efforts. Here, we have evaluated the repurposed drug pyrvinium pamoate as well as newly synthesized analogs of pyrvinium for their efficacy against filarial worms in vitro and in vivo. We found that pyrvinium pamoate, tetrahydropyrvinium and one of the analogs were highly potent in inhibiting worms in in vitro whole-worm screening assays, and that all three compounds reduced female worm fecundity and inhibited embryogenesis in the Brugia pahangi-gerbil in vivo model of infection.
Collapse
Affiliation(s)
- Emma L. Gunderson
- Department of Pharmaceutical Chemistry, University of California San Francisco, San Francisco, CA 94158, USA; (E.L.G.); (C.B.); (C.A.B.); (C.F.); (M.L.); (I.V.); (K.-C.L.); (A.R.R.)
| | - Clifford Bryant
- Department of Pharmaceutical Chemistry, University of California San Francisco, San Francisco, CA 94158, USA; (E.L.G.); (C.B.); (C.A.B.); (C.F.); (M.L.); (I.V.); (K.-C.L.); (A.R.R.)
| | - Christina A. Bulman
- Department of Pharmaceutical Chemistry, University of California San Francisco, San Francisco, CA 94158, USA; (E.L.G.); (C.B.); (C.A.B.); (C.F.); (M.L.); (I.V.); (K.-C.L.); (A.R.R.)
| | - Chelsea Fischer
- Department of Pharmaceutical Chemistry, University of California San Francisco, San Francisco, CA 94158, USA; (E.L.G.); (C.B.); (C.A.B.); (C.F.); (M.L.); (I.V.); (K.-C.L.); (A.R.R.)
| | - Mona Luo
- Department of Pharmaceutical Chemistry, University of California San Francisco, San Francisco, CA 94158, USA; (E.L.G.); (C.B.); (C.A.B.); (C.F.); (M.L.); (I.V.); (K.-C.L.); (A.R.R.)
| | - Ian Vogel
- Department of Pharmaceutical Chemistry, University of California San Francisco, San Francisco, CA 94158, USA; (E.L.G.); (C.B.); (C.A.B.); (C.F.); (M.L.); (I.V.); (K.-C.L.); (A.R.R.)
| | - Kee-Chong Lim
- Department of Pharmaceutical Chemistry, University of California San Francisco, San Francisco, CA 94158, USA; (E.L.G.); (C.B.); (C.A.B.); (C.F.); (M.L.); (I.V.); (K.-C.L.); (A.R.R.)
| | - Shabnam Jawahar
- Molecular Parasitology, New York Blood Center, Lindsley F. Kimball Research Institute, New York, NY 10065, USA; (S.J.); (N.T.); (D.V.)
| | - Nancy Tricoche
- Molecular Parasitology, New York Blood Center, Lindsley F. Kimball Research Institute, New York, NY 10065, USA; (S.J.); (N.T.); (D.V.)
| | - Denis Voronin
- Molecular Parasitology, New York Blood Center, Lindsley F. Kimball Research Institute, New York, NY 10065, USA; (S.J.); (N.T.); (D.V.)
| | - Christopher Corbo
- Department of Biological Sciences, Wagner College, Staten Island, NY 10301, USA;
| | - Rene B. Ayiseh
- ANDI Centre of Excellence for Onchocerciasis Drug Research, Biotechnology Unit, Faculty of Science, University of Buea, Buea P.O. Box 63, Cameroon; (R.B.A.); (F.P.T.M.); (G.E.M.); (F.C.-N.)
| | - Faustin P. T. Manfo
- ANDI Centre of Excellence for Onchocerciasis Drug Research, Biotechnology Unit, Faculty of Science, University of Buea, Buea P.O. Box 63, Cameroon; (R.B.A.); (F.P.T.M.); (G.E.M.); (F.C.-N.)
| | - Glory E. Mbah
- ANDI Centre of Excellence for Onchocerciasis Drug Research, Biotechnology Unit, Faculty of Science, University of Buea, Buea P.O. Box 63, Cameroon; (R.B.A.); (F.P.T.M.); (G.E.M.); (F.C.-N.)
- Higher Teacher Training College (HTTC), The University of Bamenda, Bamenda P.O. Box 39, Cameroon
| | - Fidelis Cho-Ngwa
- ANDI Centre of Excellence for Onchocerciasis Drug Research, Biotechnology Unit, Faculty of Science, University of Buea, Buea P.O. Box 63, Cameroon; (R.B.A.); (F.P.T.M.); (G.E.M.); (F.C.-N.)
| | - Brenda Beerntsen
- Department of Veterinary Pathobiology, University of Missouri-Columbia, Columbia, MO 65211, USA;
| | - Adam R. Renslo
- Department of Pharmaceutical Chemistry, University of California San Francisco, San Francisco, CA 94158, USA; (E.L.G.); (C.B.); (C.A.B.); (C.F.); (M.L.); (I.V.); (K.-C.L.); (A.R.R.)
| | - Sara Lustigman
- Molecular Parasitology, New York Blood Center, Lindsley F. Kimball Research Institute, New York, NY 10065, USA; (S.J.); (N.T.); (D.V.)
| | - Judy A. Sakanari
- Department of Pharmaceutical Chemistry, University of California San Francisco, San Francisco, CA 94158, USA; (E.L.G.); (C.B.); (C.A.B.); (C.F.); (M.L.); (I.V.); (K.-C.L.); (A.R.R.)
| |
Collapse
|
5
|
Kwofie SK, Broni E, Yunus FU, Nsoh J, Adoboe D, Miller WA, Wilson MD. Molecular Docking Simulation Studies Identifies Potential Natural Product Derived-Antiwolbachial Compounds as Filaricides against Onchocerciasis. Biomedicines 2021; 9:biomedicines9111682. [PMID: 34829911 PMCID: PMC8615632 DOI: 10.3390/biomedicines9111682] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2021] [Revised: 10/20/2021] [Accepted: 10/27/2021] [Indexed: 11/16/2022] Open
Abstract
Onchocerciasis is the leading cause of blindness and severe skin lesions which remain a major public health problem, especially in tropical areas. The widespread use of antibiotics and the long duration required for effective treatment continues to add to the increasing global menace of multi-resistant pathogens. Onchocerca volvulus harbors the endosymbiont bacteria Wolbachia, essential for the normal development of embryos, larvae and long-term survival of the adult worm, O. volvulus. We report here results of using structure-based drug design (SBDD) approach aimed at identifying potential novel Wolbachia inhibitors from natural products against the Wolbachia surface protein (WSP). The protein sequence of the WSP with UniProtKB identifier Q0RAI4 was used to model the three-dimensional (3D) structure via homology modelling techniques using three different structure-building algorithms implemented in Modeller, I-TASSER and Robetta. Out of the 15 generated models of WSP, one was selected as the most reasonable quality model which had 82, 15.5, 1.9 and 0.5% of the amino acid residues in the most favored regions, additionally allowed regions, generously allowed regions and disallowed regions, respectively, based on the Ramachandran plot. High throughput virtual screening was performed via Autodock Vina with a library comprising 42,883 natural products from African and Chinese databases, including 23 identified anti-Onchocerca inhibitors. The top six compounds comprising ZINC000095913861, ZINC000095486235, ZINC000035941652, NANPDB4566, acetylaleuritolic acid and rhemannic acid had binding energies of −12.7, −11.1, −11.0, −11, −10.3 and −9.5 kcal/mol, respectively. Molecular dynamics simulations including molecular mechanics Poisson-Boltzmann (MMPBSA) calculations reinforced the stability of the ligand-WSP complexes and plausible binding mechanisms. The residues Arg45, Tyr135, Tyr148 and Phe195 were predicted as potential novel critical residues required for ligand binding in pocket 1. Acetylaleuritolic acid and rhemannic acid (lantedene A) have previously been shown to possess anti-onchocercal activity. This warrants the need to evaluate the anti-WSP activity of the identified molecules. The study suggests the exploitation of compounds which target both pockets 1 and 2, by investigating their potential for effective depletion of Wolbachia. These compounds were predicted to possess reasonably good pharmacological profiles with insignificant toxicity and as drug-like. The compounds were computed to possess biological activity including antibacterial, antiparasitic, anthelmintic and anti-rickettsials. The six natural products are potential novel antiwolbachial agents with insignificant toxicities which can be explored further as filaricides for onchocerciasis.
Collapse
Affiliation(s)
- Samuel K. Kwofie
- Department of Biomedical Engineering, School of Engineering Sciences, College of Basic and Applied Sciences, University of Ghana, PMB LG 77, Legon, Accra LG 77, Ghana; (E.B.); (F.U.Y.); (J.N.); (D.A.)
- West African Centre for Cell Biology of Infectious Pathogens, Department of Biochemistry, Cell and Molecular Biology, College of Basic and Applied Sciences, University of Ghana, Accra LG 54, Ghana
- Correspondence: ; Tel.: +233-203-797922
| | - Emmanuel Broni
- Department of Biomedical Engineering, School of Engineering Sciences, College of Basic and Applied Sciences, University of Ghana, PMB LG 77, Legon, Accra LG 77, Ghana; (E.B.); (F.U.Y.); (J.N.); (D.A.)
- West African Centre for Cell Biology of Infectious Pathogens, Department of Biochemistry, Cell and Molecular Biology, College of Basic and Applied Sciences, University of Ghana, Accra LG 54, Ghana
- Department of Parasitology, Noguchi Memorial Institute for Medical Research (NMIMR), College of Health Sciences (CHS), University of Ghana, P.O. Box LG 581, Legon, Accra LG 581, Ghana;
| | - Faruk U. Yunus
- Department of Biomedical Engineering, School of Engineering Sciences, College of Basic and Applied Sciences, University of Ghana, PMB LG 77, Legon, Accra LG 77, Ghana; (E.B.); (F.U.Y.); (J.N.); (D.A.)
| | - John Nsoh
- Department of Biomedical Engineering, School of Engineering Sciences, College of Basic and Applied Sciences, University of Ghana, PMB LG 77, Legon, Accra LG 77, Ghana; (E.B.); (F.U.Y.); (J.N.); (D.A.)
| | - Dela Adoboe
- Department of Biomedical Engineering, School of Engineering Sciences, College of Basic and Applied Sciences, University of Ghana, PMB LG 77, Legon, Accra LG 77, Ghana; (E.B.); (F.U.Y.); (J.N.); (D.A.)
| | - Whelton A. Miller
- Department of Medicine, Loyola University Medical Center, Maywood, IL 60153, USA;
- Department of Molecular Pharmacology and Neuroscience, Loyola University Medical Center, Maywood, IL 60153, USA
- Department of Chemical and Biomolecular Engineering, School of Engineering and Applied Science, University of Pennsylvania, Philadelphia, IL 19104, USA
| | - Michael D. Wilson
- Department of Parasitology, Noguchi Memorial Institute for Medical Research (NMIMR), College of Health Sciences (CHS), University of Ghana, P.O. Box LG 581, Legon, Accra LG 581, Ghana;
- Department of Medicine, Loyola University Medical Center, Maywood, IL 60153, USA;
| |
Collapse
|
6
|
Ngwewondo A, Scandale I, Specht S. Onchocerciasis drug development: from preclinical models to humans. Parasitol Res 2021; 120:3939-3964. [PMID: 34642800 PMCID: PMC8599318 DOI: 10.1007/s00436-021-07307-4] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2021] [Accepted: 08/30/2021] [Indexed: 11/30/2022]
Abstract
Twenty diseases are recognized as neglected tropical diseases (NTDs) by World Health Assembly resolutions, including human filarial diseases. The end of NTDs is embedded within the Sustainable Development Goals for 2030, under target 3.3. Onchocerciasis afflicts approximately 20.9 million people worldwide with > 90% of those infected residing in Africa. Control programs have made tremendous efforts in the management of onchocerciasis by mass drug administration and aerial larviciding; however, disease elimination is not yet achieved. In the new WHO roadmap, it is recognized that new drugs or drug regimens that kill or permanently sterilize adult filarial worms would significantly improve elimination timelines and accelerate the achievement of the program goal of disease elimination. Drug development is, however, handicapped by high attrition rates, and many promising molecules fail in preclinical development or in subsequent toxicological, safety and efficacy testing; thus, research and development (R&D) costs are, in aggregate, very high. Drug discovery and development for NTDs is largely driven by unmet medical needs put forward by the global health community; the area is underfunded and since no high return on investment is possible, there is no dedicated drug development pipeline for human filariasis. Repurposing existing drugs is one approach to filling the drug development pipeline for human filariasis. The high cost and slow pace of discovery and development of new drugs has led to the repurposing of “old” drugs, as this is more cost-effective and allows development timelines to be shortened. However, even if a drug is marketed for a human or veterinary indication, the safety margin and dosing regimen will need to be re-evaluated to determine the risk in humans. Drug repurposing is a promising approach to enlarging the pool of active molecules in the drug development pipeline. Another consideration when providing new treatment options is the use of combinations, which is not addressed in this review. We here summarize recent advances in the late preclinical or early clinical stage in the search for a potent macrofilaricide, including drugs against the nematode and against its endosymbiont, Wolbachia pipientis.
Collapse
Affiliation(s)
- Adela Ngwewondo
- Centre of Medical Research, Institute of Medical Research and Medicinal Plants Studies (IMPM), P.O. Box13033, Yaoundé, Cameroon
- Drugs for Neglected Diseases Initiative, Chemin Camille-Vidart 15, 1202, Geneva, Switzerland
| | - Ivan Scandale
- Drugs for Neglected Diseases Initiative, Chemin Camille-Vidart 15, 1202, Geneva, Switzerland
| | - Sabine Specht
- Drugs for Neglected Diseases Initiative, Chemin Camille-Vidart 15, 1202, Geneva, Switzerland.
| |
Collapse
|
7
|
Abraham D, Graham-Brown J, Carter D, Gray SA, Hess JA, Makepeace BL, Lustigman S. Development of a recombinant vaccine against human onchocerciasis. Expert Rev Vaccines 2021; 20:1459-1470. [PMID: 34488533 DOI: 10.1080/14760584.2021.1977125] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
INTRODUCTION Human onchocerciasis caused by the filarial nematode parasite Onchocerca volvulus remains a major cause of debilitating disease infecting millions primarily in Sub-Saharan Africa. The development of a prophylactic vaccine, along with mass drug administration, would facilitate meeting the goal of onchocerciasis elimination by 2030. AREAS COVERED Models used to study immunity to Onchocerca include natural infection of cattle with Onchocerca ochengi and O. volvulus infective third-stage larvae implanted within diffusion chambers in mice. A vaccine, comprised of two adjuvanted recombinant antigens, induced protective immunity in genetically diverse mice suggesting that it will function similarly in diverse human populations. These antigens were recognized by immune humans and also induced protective immunity against Brugia malayi. We describe the development of a fusion protein composed of the two vaccine antigens with the plan to test the vaccine in cows and non-human primates as a prelude to the initiation of phase 1 clinical trials. EXPERT OPINION The adjuvanted O. volvulus vaccine composed of two antigens Ov-103 and Ov-RAL-2 was shown to be consistently effective at inducing protective immunity using multiple immune mechanisms. The vaccine is ready for further evaluation in other animal models before moving to clinical trials in humans.
Collapse
Affiliation(s)
- David Abraham
- Department of Microbiology and Immunology, Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, PA, USA
| | - John Graham-Brown
- Institute of Infection, Veterinary & Ecological Sciences, University of Liverpool, Liverpool, UK
| | | | | | - Jessica A Hess
- Department of Microbiology and Immunology, Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, PA, USA
| | - Benjamin L Makepeace
- Institute of Infection, Veterinary & Ecological Sciences, University of Liverpool, Liverpool, UK
| | - Sara Lustigman
- Laboratory of Molecular Parasitology, Lindsley F. Kimball Research Institute, New York Blood Center, New York, NY, USA
| |
Collapse
|
8
|
High-content approaches to anthelmintic drug screening. Trends Parasitol 2021; 37:780-789. [PMID: 34092518 DOI: 10.1016/j.pt.2021.05.004] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2021] [Revised: 05/03/2021] [Accepted: 05/11/2021] [Indexed: 11/23/2022]
Abstract
Most anthelmintics were discovered through in vivo screens using animal models of infection. Developing in vitro assays for parasitic worms presents several challenges. The lack of in vitro life cycle culture protocols requires harvesting worms from vertebrate hosts or vectors, limiting assay throughput. Once worms are removed from the host environment, established anthelmintics often show no obvious phenotype - raising concerns about the predictive value of many in vitro assays. However, with recent progress in understanding how anthelmintics subvert host-parasite interactions, and breakthroughs in high-content imaging and machine learning, in vitro assays have the potential to discern subtle cryptic parasite phenotypes. These may prove better endpoints than conventional in vitro viability assays.
Collapse
|