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Haghiri A, Price DJ, Fitzpatrick P, Dini S, Rajasekhar M, Fanello C, Tarning J, Watson J, White NJ, Simpson JA. Evidence Based Optimal Dosing of Intravenous Artesunate in Children with Severe Falciparum Malaria. Clin Pharmacol Ther 2023; 114:1304-1312. [PMID: 37666798 DOI: 10.1002/cpt.3041] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2023] [Accepted: 08/26/2023] [Indexed: 09/06/2023]
Abstract
The majority of deaths from malaria are in young African children. Parenteral artesunate (ARS) is the first-line treatment for severe falciparum malaria. Since 2015, the World Health Organization has recommended individual doses of 3 mg/kg for children weighing < 20 kg. Recently, the US Food and Drug Administration (FDA) has challenged this recommendation, based on a simulated pediatric population, and argued for a lower dose in younger children (2.4 mg/kg). In this study, we performed population pharmacokinetic (PK) modeling of plasma concentration data from 80 children with severe falciparum malaria in the Democratic Republic of Congo who were given 2.4 mg/kg of ARS intravenously. Bayesian hierarchical modeling and a two-compartment parent drug-metabolite PK model for ARS were used to describe the population PKs of ARS and its main biologically active metabolite dihydroartemisinin. We then generated a virtual population representative of the target population in which the drug is used and simulated the total first-dose exposures. Our study shows that the majority of younger children given the lower 2.4 mg/kg dose of intravenous ARS do not reach the same drug exposures as older children above 20 kg. This finding supports withdrawal of the FDA's recent lower ARS dose recommendation as parenteral ARS is an extremely safe and well-tolerated drug and there is potential for harm from underdosing in this rapidly lethal infection.
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Affiliation(s)
- Ali Haghiri
- Centre for Epidemiology and Biostatistics, Melbourne School of Population and Global Health, The University of Melbourne, Melbourne, Victoria, Australia
- School of Engineering, University of Leicester, Leicester, UK
| | - David J Price
- Centre for Epidemiology and Biostatistics, Melbourne School of Population and Global Health, The University of Melbourne, Melbourne, Victoria, Australia
- Doherty Institute for Infection and Immunity, The Royal Melbourne Hospital, The University of Melbourne, Melbourne, Victoria, Australia
| | - Phoebe Fitzpatrick
- Centre for Epidemiology and Biostatistics, Melbourne School of Population and Global Health, The University of Melbourne, Melbourne, Victoria, Australia
| | - Saber Dini
- Centre for Epidemiology and Biostatistics, Melbourne School of Population and Global Health, The University of Melbourne, Melbourne, Victoria, Australia
| | - Megha Rajasekhar
- Centre for Epidemiology and Biostatistics, Melbourne School of Population and Global Health, The University of Melbourne, Melbourne, Victoria, Australia
| | - Caterina Fanello
- Nuffield Department of Medicine, Centre for Tropical Medicine and Global Health, Oxford University, Oxford, UK
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Joel Tarning
- Nuffield Department of Medicine, Centre for Tropical Medicine and Global Health, Oxford University, Oxford, UK
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - James Watson
- Nuffield Department of Medicine, Centre for Tropical Medicine and Global Health, Oxford University, Oxford, UK
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Nicholas J White
- Nuffield Department of Medicine, Centre for Tropical Medicine and Global Health, Oxford University, Oxford, UK
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Julie A Simpson
- Centre for Epidemiology and Biostatistics, Melbourne School of Population and Global Health, The University of Melbourne, Melbourne, Victoria, Australia
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Abstract
Severe malaria is a medical emergency. It is a major cause of preventable childhood death in tropical countries. Severe malaria justifies considerable global investment in malaria control and elimination yet, increasingly, international agencies, funders and policy makers are unfamiliar with it, and so it is overlooked. In sub-Saharan Africa, severe malaria is overdiagnosed in clinical practice. Approximately one third of children diagnosed with severe malaria have another condition, usually sepsis, as the cause of their severe illness. But these children have a high mortality, contributing substantially to the number of deaths attributed to 'severe malaria'. Simple well-established tests, such as examination of the thin blood smear and the full blood count, improve the specificity of diagnosis and provide prognostic information in severe malaria. They should be performed more widely. Early administration of artesunate and broad-spectrum antibiotics to all children with suspected severe malaria would reduce global malaria mortality.
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Affiliation(s)
- Nicholas J White
- Mahidol Oxford Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand.
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK.
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3
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Kalkman LC, Hanscheid T, Krishna S, Kremsner PG, Grobusch MP. Antimalarial treatment in infants. Expert Opin Pharmacother 2022; 23:1711-1726. [PMID: 36174125 DOI: 10.1080/14656566.2022.2130687] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
INTRODUCTION Malaria in infants is common in high-transmission settings, especially in infants >6 months. Infants undergo physiological changes impacting pharmacokinetics and pharmacodynamics of anti-malarial drugs and, consequently, the safety and efficacy of malaria treatment. Yet, treatment guidelines and evidence on pharmacological interventions for malaria often fail to address this vulnerable age-group. This review aims to summarise the available data on anti-malarial treatment in infants. AREAS COVERED The standard recommended treatments for severe and uncomplicated malaria are generally safe and effective in infants. However, infants have an increased risk of drug-related vomiting and have distinct pharmacokinetic parameters of antimalarials compared with older patients. These include larger volumes of distribution, higher clearance rates and immature enzyme systems. Consequently, infants with malaria may be at increased risk of treatment failure and drug toxicity. EXPERT OPINION Knowledge expansion to optimize treatment can be achieved by including more infants in antimalarial drug trials and by reporting separately on treatment outcomes in infants. Additional evidence on the efficacy, safety, tolerability, acceptability and effectiveness of ACTs in infants is needed, as well as population pharmacokinetics studies on antimalarials in the infant population.
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Affiliation(s)
- Laura C Kalkman
- Center of Tropical Medicine and Travel Medicine, Department of Infectious Diseases, Amsterdam University Medical Centers, location Amsterdam, Amsterdam Infection & Immunity, Amsterdam Public Health, University of Amsterdam, Amsterdam, The Netherlands
| | - Thomas Hanscheid
- Instituto de Microbiologia, Faculdade de Medicina, Universidade de Lisboa, Lisbon, Portugal
| | - Sanjeev Krishna
- Institut für Tropenmedizin, Eberhard Karls Universität Tübingen, and German Center for Infection Research (DZIF), Tübingen, Germany.,Centre de Recherches Médicales de Lambaréné (CERMEL), Lambaréné, Gabon.,Clinical Academic Group, Institute for Infection and Immunity, and St. George's University Hospitals NHS Foundation Trust, St. George's University of London, London, UK
| | - Peter G Kremsner
- Institut für Tropenmedizin, Eberhard Karls Universität Tübingen, and German Center for Infection Research (DZIF), Tübingen, Germany.,Centre de Recherches Médicales de Lambaréné (CERMEL), Lambaréné, Gabon
| | - Martin P Grobusch
- Center of Tropical Medicine and Travel Medicine, Department of Infectious Diseases, Amsterdam University Medical Centers, location Amsterdam, Amsterdam Infection & Immunity, Amsterdam Public Health, University of Amsterdam, Amsterdam, The Netherlands.,Institut für Tropenmedizin, Eberhard Karls Universität Tübingen, and German Center for Infection Research (DZIF), Tübingen, Germany.,Centre de Recherches Médicales de Lambaréné (CERMEL), Lambaréné, Gabon.,Institute of Infectious Diseases and Molecular Medicine, University of Cape Town, Cape Town, South Africa.,Masanga Medical Research Unit (MMRU), Masanga, Sierra Leone
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4
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White NJ, Watson JA, Simpson JA. Severe Malaria, Pascalian Therapeutics, and the US Food and Drug Administration (FDA). Clin Infect Dis 2022; 75:358. [PMID: 35023549 DOI: 10.1093/cid/ciac024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Nicholas J White
- Mahidol Oxford Research Unit, Faculty of Tropical Medicine, Mahidol University, BangkokThailand
| | - James A Watson
- Mahidol Oxford Research Unit, Faculty of Tropical Medicine, Mahidol University, BangkokThailand
| | - Julie A Simpson
- Biostatistics Unit, Centre for Epidemiology and Biostatistics, Melbourne School of Population and Global Health, University of Melbourne, Parkville, Victoria, Australia
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5
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Raghuwanshi AS, Kumar A, Raghuwanshi N, Singh SK, Singh AK, Tripathi U, Kaviraj S, Singh S. Development of a process for large scale production of PfRH5 in E. coli expression system. Int J Biol Macromol 2021; 188:169-179. [PMID: 34364940 DOI: 10.1016/j.ijbiomac.2021.08.014] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2021] [Revised: 08/02/2021] [Accepted: 08/03/2021] [Indexed: 10/20/2022]
Abstract
The Plasmodium falciparum reticulocyte binding protein homologue 5 (PfRH5) has recently shown great promise to be developed as a vaccine candidate to prevent blood-stage malaria. However, because of its molecular complexity, most previous efforts were focused on expressing PfRH5 in its native and soluble form. Here, we describe the E. coli expression of full-length PfRH5 as inclusion bodies (IBs), followed by its high cell density fermentation at 1, 5 and 30 L scale. Denatured full-length PfRH5 was purified using a two-step chromatography process before being refolded using design of experiments (DoE). Refolded PfRH5 was further purified using size exclusion chromatography (SEC), recovering high purity antigen with an overall yield of 102 mg/L from fermentation cell harvest. Purified PfRH5 was further characterized using orthogonal analytical methods, and a short-term stability study revealed -80 °C as an optimum storage temperature. Moreover, refolded, and purified PfRH5, when formulated with adjuvant Glucopyranosyl A lipid stable emulsion (GLA-SE), elicited high antibody titers in BALB/c mice, proving its potential to neutralize the blood-stage malarial parasite. Here, we establish an E. coli-based process platform for the large-scale cGMP production of full-length PfRH5, enabling global malaria vaccine development efforts.
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Affiliation(s)
- Arjun Singh Raghuwanshi
- Vaccine Formulation and Research Center, Gennova Biopharmaceuticals Limited, Pune 411057, Maharashtra, India
| | - Ankit Kumar
- Vaccine Formulation and Research Center, Gennova Biopharmaceuticals Limited, Pune 411057, Maharashtra, India
| | - Navdeep Raghuwanshi
- Vaccine Formulation and Research Center, Gennova Biopharmaceuticals Limited, Pune 411057, Maharashtra, India
| | - Shravan Kumar Singh
- Vaccine Formulation and Research Center, Gennova Biopharmaceuticals Limited, Pune 411057, Maharashtra, India
| | - Avinash Kumar Singh
- Vaccine Formulation and Research Center, Gennova Biopharmaceuticals Limited, Pune 411057, Maharashtra, India
| | - Umanath Tripathi
- Vaccine Formulation and Research Center, Gennova Biopharmaceuticals Limited, Pune 411057, Maharashtra, India
| | - Swarnendu Kaviraj
- Vaccine Formulation and Research Center, Gennova Biopharmaceuticals Limited, Pune 411057, Maharashtra, India
| | - Sanjay Singh
- Vaccine Formulation and Research Center, Gennova Biopharmaceuticals Limited, Pune 411057, Maharashtra, India.
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6
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Zaloumis SG, Whyte JM, Tarning J, Krishna S, McCaw JM, Cao P, White MT, Dini S, Fowkes FJI, Maude RJ, Kremsner P, Dondorp A, Price RN, White NJ, Simpson JA. Development and Validation of an In Silico Decision Tool To Guide Optimization of Intravenous Artesunate Dosing Regimens for Severe Falciparum Malaria Patients. Antimicrob Agents Chemother 2021; 65:e02346-20. [PMID: 33685888 PMCID: PMC8316083 DOI: 10.1128/aac.02346-20] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2020] [Accepted: 02/25/2021] [Indexed: 01/13/2023] Open
Abstract
Most deaths from severe falciparum malaria occur within 24 h of presentation to a hospital. Intravenous (i.v.) artesunate is the first-line treatment for severe falciparum malaria, but its efficacy may be compromised by delayed parasitological responses. In patients with severe malaria, the life-saving benefit of the artemisinin derivatives is their ability to clear circulating parasites rapidly, before they can sequester and obstruct the microcirculation. To evaluate the dosing of i.v. artesunate for the treatment of artemisinin-sensitive and reduced ring stage sensitivity to artemisinin severe falciparum malaria infections, Bayesian pharmacokinetic-pharmacodynamic modeling of data from 94 patients with severe malaria (80 children from Africa and 14 adults from Southeast Asia) was performed. Assuming that delayed parasite clearance reflects a loss of ring stage sensitivity to artemisinin derivatives, the median (95% credible interval) percentage of patients clearing ≥99% of parasites within 24 h (PC24≥99%) for standard (2.4 mg/kg body weight i.v. artesunate at 0 and 12 h) and simplified (4 mg/kg i.v. artesunate at 0 h) regimens was 65% (52.5% to 74.5%) versus 44% (25% to 61.5%) for adults, 62% (51.5% to 74.5%) versus 39% (20.5% to 58.5%) for larger children (≥20 kg), and 60% (48.5% to 70%) versus 36% (20% to 53.5%) for smaller children (<20 kg). The upper limit of the credible intervals for all regimens was below a PC24≥99% of 80%, a threshold achieved on average in clinical studies of severe falciparum malaria infections. In severe falciparum malaria caused by parasites with reduced ring stage susceptibility to artemisinin, parasite clearance is predicted to be slower with both the currently recommended and proposed simplified i.v. artesunate dosing regimens.
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Affiliation(s)
- Sophie G Zaloumis
- Centre for Epidemiology & Biostatistics, Melbourne School of Population and Global Health, University of Melbourne, Melbourne, Australia
| | - Jason M Whyte
- Centre of Excellence for Biosecurity Risk Analysis, School of BioSciences, University of Melbourne, Melbourne, Australia
- Australian Research Council Centre of Excellence for Mathematical and Statistical Frontiers, School of Mathematics and Statistics, University of Melbourne, Melbourne, Australia
| | - Joel Tarning
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
| | - Sanjeev Krishna
- Institute for Infection and Immunity, St. George's Hospital, University of London, London, United Kingdom
| | - James M McCaw
- Centre for Epidemiology & Biostatistics, Melbourne School of Population and Global Health, University of Melbourne, Melbourne, Australia
- School of Mathematics and Statistics, University of Melbourne, Melbourne, Australia
| | - Pengxing Cao
- School of Mathematics and Statistics, University of Melbourne, Melbourne, Australia
| | - Michael T White
- Department of Parasites and Insect Vectors, Institut Pasteur, Paris, France
| | - Saber Dini
- Centre for Epidemiology & Biostatistics, Melbourne School of Population and Global Health, University of Melbourne, Melbourne, Australia
| | - Freya J I Fowkes
- Centre for Epidemiology & Biostatistics, Melbourne School of Population and Global Health, University of Melbourne, Melbourne, Australia
- Disease Elimination Program, Burnet Institute, Melbourne, Australia
| | - Richard J Maude
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
- Harvard TH Chan School of P`ublic Health, Harvard University, Boston, Massachusetts, USA
| | - Peter Kremsner
- Centre de Recherches Médicales de Lambaréné, Lambaréné, Gabon
- Gabon and Institut für Tropenmedizin, University of Tübingen, Tübingen, Germany
| | - Arjen Dondorp
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
| | - Ric N Price
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
- Global Health Division, Menzies School of Health Research and Charles Darwin University, Darwin, Northern Territory, Australia
| | - Nicholas J White
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
| | - Julie A Simpson
- Centre for Epidemiology & Biostatistics, Melbourne School of Population and Global Health, University of Melbourne, Melbourne, Australia
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7
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Zech J, Salaymeh N, Hunt NH, Mäder K, Golenser J. Efficient Treatment of Experimental Cerebral Malaria by an Artemisone-SMEDDS System: Impact of Application Route and Dosing Frequency. Antimicrob Agents Chemother 2021; 65:e02106-20. [PMID: 33558284 PMCID: PMC8097435 DOI: 10.1128/aac.02106-20] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2020] [Accepted: 01/28/2021] [Indexed: 11/24/2022] Open
Abstract
Artemisone (ART) has been successfully tested in vitro and in animal models against several diseases. However, its poor aqueous solubility and limited chemical stability are serious challenges. We developed a self-microemulsifying drug delivery system (SMEDDS) that overcomes these limitations. Here, we demonstrate the efficacy of this formulation against experimental cerebral malaria in mice and the impact of its administration using different routes (gavage, intranasal delivery, and parenteral injections) and frequency on the efficacy of the treatment. The minimal effective daily oral dose was 20 mg/kg. We found that splitting a dose of 20 mg/kg ART given every 24 h, by administering two doses of 10 mg/kg each every 12 h, was highly effective and gave far superior results compared to 20 mg/kg once daily. We obtained the best results with nasal treatment; oral treatment was ranked second, and the least effective route of administration was intraperitoneal injection. A complete cure of experimental cerebral malaria could be achieved through choosing the optimal route of application, dose, and dosing interval. Altogether, the developed formulation combines easy manufacturing with high stability and could be a successful and very versatile carrier for the delivery of ART in the treatment of human severe malaria.
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Affiliation(s)
- Johanna Zech
- Institute of Pharmacy, Martin Luther University Halle-Wittenberg, Halle (Saale), Germany
| | - Nadeen Salaymeh
- Department of Microbiology and Molecular Genetics, The Kuvin Centre for the Study of Infectious and Tropical Diseases, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Nicholas H Hunt
- Discipline of Pathology, School of Medical Sciences, Faculty of Medicine and Health, The University of Sydney, NSW, Australia
| | - Karsten Mäder
- Institute of Pharmacy, Martin Luther University Halle-Wittenberg, Halle (Saale), Germany
| | - Jacob Golenser
- Department of Microbiology and Molecular Genetics, The Kuvin Centre for the Study of Infectious and Tropical Diseases, The Hebrew University of Jerusalem, Jerusalem, Israel
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8
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Kitabi E, Bensman TJ, Earp JC, Chilukuri DM, Smith H, Ball L, O'Shaughnessy E, Yasinskaya Y, Colangelo PM, Reynolds KS. Effect of Body Weight and Age on the Pharmacokinetics of Dihydroartemisinin: FDA Basis for Dose Determination of Artesunate for Injection in Pediatric Patients with Severe Malaria. Clin Infect Dis 2021; 73:903-906. [PMID: 33605994 DOI: 10.1093/cid/ciab149] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2020] [Accepted: 02/12/2021] [Indexed: 11/12/2022] Open
Abstract
For treatment of severe malaria, the WHO recommends 3 mg/kg intravenous artesunate in pediatric patients weighing less than 20 kg. Here we describe FDA's rationale for selecting 2.4 mg/kg in pediatric patients weighing less than 20 kg based on literature review and independent analyses.
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Affiliation(s)
- Eliford Kitabi
- Division of Pharmacometrics, Office of Clinical Pharmacology, Office of Translational Sciences, Center for Drug Evaluation and Research, US Food and Drug Administration
| | - Timothy J Bensman
- Division of Infectious Disease Pharmacology, Office of Clinical Pharmacology, Office of Translational Sciences, Center for Drug Evaluation and Research, US Food and Drug Administration
| | - Justin C Earp
- Division of Pharmacometrics, Office of Clinical Pharmacology, Office of Translational Sciences, Center for Drug Evaluation and Research, US Food and Drug Administration
| | - Dakshina M Chilukuri
- Division of Infectious Disease Pharmacology, Office of Clinical Pharmacology, Office of Translational Sciences, Center for Drug Evaluation and Research, US Food and Drug Administration
| | - Heidi Smith
- Division of Anti-infectives, Office of Infectious Diseases, Office of New Drugs, Center for Drug Evaluation and Research, US Food and Drug Administration
| | - Leslie Ball
- Division of Anti-infectives, Office of Infectious Diseases, Office of New Drugs, Center for Drug Evaluation and Research, US Food and Drug Administration
| | - Elizabeth O'Shaughnessy
- Division of Anti-infectives, Office of Infectious Diseases, Office of New Drugs, Center for Drug Evaluation and Research, US Food and Drug Administration
| | - Yuliya Yasinskaya
- Division of Anti-infectives, Office of Infectious Diseases, Office of New Drugs, Center for Drug Evaluation and Research, US Food and Drug Administration
| | - Philip M Colangelo
- Division of Infectious Disease Pharmacology, Office of Clinical Pharmacology, Office of Translational Sciences, Center for Drug Evaluation and Research, US Food and Drug Administration
| | - Kellie S Reynolds
- Division of Infectious Disease Pharmacology, Office of Clinical Pharmacology, Office of Translational Sciences, Center for Drug Evaluation and Research, US Food and Drug Administration
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9
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Development of sustainable research excellence with a global perspective on infectious diseases: Centre de Recherches Médicales de Lambaréné (CERMEL), Gabon. Wien Klin Wochenschr 2021; 133:500-508. [PMID: 33398458 PMCID: PMC7781170 DOI: 10.1007/s00508-020-01794-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2020] [Accepted: 11/30/2020] [Indexed: 11/17/2022]
Abstract
Medical research in sub-Saharan Africa is of high priority for societies to respond adequately to local health needs. Often enough it remains a challenge to build up capacity in infrastructure and human resources to highest international standards and to sustain this over mid-term to long-term periods due to difficulties in obtaining long-term institutional core funding, attracting highly qualified scientists for medical research and coping with ever changing structural and political environments. The Centre de Recherches Médicales de Lambaréné (CERMEL) serves as model for how to overcome such challenges and to continuously increase its impact on medical care in Central Africa and beyond. Starting off as a research annex to the Albert Schweitzer Hospital in Lambaréné, Gabon, it has since then expanded its activities to academic and regulatory clinical trials for drugs, vaccines and diagnostics in the field of malaria, tuberculosis, and a wide range of poverty related and neglected tropical infectious diseases. Advancing bioethics in medical research in Africa and steadily improving its global networks and infrastructures, CERMEL serves as a reference centre for several international consortia. In close collaboration with national authorities, CERMEL has become one of the main training hubs for medical research in Central Africa. It is hoped that CERMEL and its leitmotiv “to improve medical care for local populations” will serve as an inspiration to other institutions in sub-Saharan Africa to further increase African capacity to advance medicine.
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Manda-Taylor L, Liomba A, Taylor TE, Elwell K. Barriers and Facilitators to Obtaining Informed Consent in a Critical Care Pediatric Research Ward in Southern Malawi. J Empir Res Hum Res Ethics 2020; 14:152-168. [PMID: 30866724 DOI: 10.1177/1556264619830859] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Informed consent is an ethical requirement in clinical research. Obtaining informed consent is challenging in resource-constrained settings. We report results of a formative qualitative study that examined factors that facilitate and hinder informed consent for clinical research among critically ill children in Malawi. We argue that truly informed consent in a pediatric intensive care unit (PICU) is challenged by parental distress, time constraints when balancing care for critically ill patients with research-related tasks, and social hierarchies and community mistrust toward certain research procedures. We interviewed health care providers and parents of children attending a critical care unit to identify potential challenges and solicit strategies for addressing them. Providers and caregivers suggested practical solutions to enhance research participant understanding of clinical trial research, including the use of visual materials, community engagement strategies, and using patients as advocates in promoting understanding of research procedures.
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11
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Jones S, Hodel EM, Sharma R, Kay K, Hastings IM. Optimal Treatments for Severe Malaria and the Threat Posed by Artemisinin Resistance. J Infect Dis 2020; 219:1243-1253. [PMID: 30517708 PMCID: PMC6452316 DOI: 10.1093/infdis/jiy649] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2018] [Accepted: 11/07/2018] [Indexed: 01/08/2023] Open
Abstract
Background Standard treatment for severe malaria is with artesunate; patient survival in the 24 hours immediately posttreatment is the key objective. Clinical trials use clearance rates of circulating parasites as their clinical outcome, but the pathology of severe malaria is attributed primarily to noncirculating, sequestered, parasites, so there is a disconnect between existing clinical metrics and objectives. Methods We extend existing pharmacokinetic/pharmacodynamic modeling methods to simulate the treatment of 10000 patients with severe malaria and track the pathology caused by sequestered parasites. Results Our model recovered the clinical outcomes of existing studies (based on circulating parasites) and showed a “simplified” artesunate regimen was noninferior to the existing World Health Organization regimen across the patient population but resulted in worse outcomes in a subgroup of patients with infections clustered in early stages of the parasite life cycle. This same group of patients were extremely vulnerable to resistance emerging in parasite early ring stages. Conclusions We quantify patient outcomes in a manner appropriate for severe malaria with a flexible framework that allows future researchers to implement their beliefs about underlying pathology. We highlight with some urgency the threat posed to treatment of severe malaria by artemisinin resistance in parasite early ring stages.
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Affiliation(s)
- Sam Jones
- Parasitology Department, Liverpool School of Tropical Medicine, United Kingdom
| | - Eva Maria Hodel
- Parasitology Department, Liverpool School of Tropical Medicine, United Kingdom.,Department of Clinical Sciences, Liverpool School of Tropical Medicine, United Kingdom
| | - Raman Sharma
- Parasitology Department, Liverpool School of Tropical Medicine, United Kingdom
| | - Katherine Kay
- Parasitology Department, Liverpool School of Tropical Medicine, United Kingdom
| | - Ian M Hastings
- Parasitology Department, Liverpool School of Tropical Medicine, United Kingdom
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12
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Scheu K, Adegnika AA, Addo MM, Ansong D, Cramer JP, Fürst S, Kremsner PG, Kurth F, Jacobs T, May J, Ramharter M, Sylverken J, Vinnemeier CD, Agbenyega T, Rolling T. Determinants of post-malarial anemia in African children treated with parenteral artesunate. Sci Rep 2019; 9:18134. [PMID: 31792345 PMCID: PMC6888809 DOI: 10.1038/s41598-019-54639-4] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2019] [Accepted: 11/18/2019] [Indexed: 12/28/2022] Open
Abstract
The pathophysiology of malarial anemia is multifactorial and incompletely understood. We assessed mechanistic and risk factors for post-malarial anemia in Ghanaian and Gabonese children with severe P. falciparum malaria treated with parenteral artesunate followed by an oral artemisinin-combination therapy. We analyzed data from two independent studies in which children were followed on Days 7,14, and 28 after treatment with artesunate. Specific hematological parameters included the presence of hemoglobinopathies and erythropoietin. Presence of once-infected erythrocytes was assessed by flow cytometry in a sub-population. Of 143 children with a geometric mean parasitemia of 116,294/µL (95% CI: 95,574-141,505), 91 (88%) had anemia (Hb < 10 g/dL) at presentation. Hemoglobin increased after Day 7 correlating with increased erythropoiesis through adequate erythropoietin stimulation. 22 children (24%) remained anemic until Day 28. Post-artesunate delayed hemolysis was detected in 7 children (5%) with only minor differences in the dynamics of once-infected erythrocytes. Hyperparasitemia and hemoglobin at presentation were associated with anemia on Day 14. On Day 28 only lower hemoglobin at presentation was associated with anemia. Most children showed an adequate erythropoiesis and recovered from anemia within one month. Post-artesunate delayed hemolysis (PADH) and hyperparasitemia are associated with early malarial anemia and pre-existing anemia is the main determinant for prolonged anemia.
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Affiliation(s)
- Katrin Scheu
- Division of Infectious Diseases, I. Department of Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
- German Center for Infection Research (DZIF), Hamburg-Lübeck-Borstel-Riems, Germany
| | - Ayola Akim Adegnika
- Centre de Recherches Médicales de Lambaréné, Lambaréné, Gabon
- Institute of Tropical Medicine, University Medical Center Tübingen, Tübingen, Germany
- Central African Network for Tuberculosis, Aids and Malaria (CANTAM), Brazzaville, Republic of Congo
| | - Marylyn M Addo
- Division of Infectious Diseases, I. Department of Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
- German Center for Infection Research (DZIF), Hamburg-Lübeck-Borstel-Riems, Germany
- Department of Clinical Immunology of Infectious Diseases, Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany
| | - Daniel Ansong
- School of Medical Sciences, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana
| | - Jakob P Cramer
- Department of Tropical Medicine, Bernhard Nocht Institute for Tropical Medicine & I. Department of Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
- Coalition for Epidemic Preparedness Innovations (CEPI), London, UK
| | - Svenja Fürst
- Division of Infectious Diseases, I. Department of Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Peter G Kremsner
- Centre de Recherches Médicales de Lambaréné, Lambaréné, Gabon
- Institute of Tropical Medicine, University Medical Center Tübingen, Tübingen, Germany
| | - Florian Kurth
- Medizinische Klinik mit Schwerpunkt Infektiologie und Pneumologie, Charité Universitätsmedizin Berlin, Berlin, Germany
| | - Thomas Jacobs
- Protozoa Immunology, Bernhard-Nocht-Institute for Tropical Medicine, Hamburg, Germany
| | - Jürgen May
- German Center for Infection Research (DZIF), Hamburg-Lübeck-Borstel-Riems, Germany
- Department of Infectious Diseases Epidemiology, Bernhard-Nocht-Institute for Tropical Medicine, Hamburg, Germany
| | - Michael Ramharter
- Centre de Recherches Médicales de Lambaréné, Lambaréné, Gabon
- Department of Tropical Medicine, Bernhard Nocht Institute for Tropical Medicine & I. Department of Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Justice Sylverken
- School of Medical Sciences, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana
| | - Christof D Vinnemeier
- German Center for Infection Research (DZIF), Hamburg-Lübeck-Borstel-Riems, Germany
- Department of Tropical Medicine, Bernhard Nocht Institute for Tropical Medicine & I. Department of Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Tsiri Agbenyega
- School of Medical Sciences, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana
| | - Thierry Rolling
- Division of Infectious Diseases, I. Department of Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.
- German Center for Infection Research (DZIF), Hamburg-Lübeck-Borstel-Riems, Germany.
- Department of Clinical Immunology of Infectious Diseases, Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany.
- Infectious Disease Service, Memorial Sloan Kettering Cancer Center, New York, NY, USA.
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Tsuda K, Miyamoto L, Hamano S, Morimoto Y, Kangawa Y, Fukue C, Kagawa Y, Horinouchi Y, Xu W, Ikeda Y, Tamaki T, Tsuchiya K. Mechanisms of the pH- and Oxygen-Dependent Oxidation Activities of Artesunate. Biol Pharm Bull 2018; 41:555-563. [PMID: 29607928 DOI: 10.1248/bpb.b17-00855] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Artemisinin was discovered in 1971 as a constituent of the wormwood genus plant (Artemisia annua). This plant has been used as an herbal medicine to treat malaria since ancient times. The compound artemisinin has a sesquiterpene lactone bearing a peroxide group that offers its biological activity. In addition to anti-malarial activity, artemisinin derivatives have been reported to exert antitumor activity in cancer cells, and have attracted attention as potential anti-cancer drugs. Mechanisms that might explain the antitumor activities of artemisinin derivatives reportedly induction of apoptosis, angiogenesis inhibitory effects, inhibition of hypoxia-inducible factor-1α (HIF-1α) activation, and direct DNA injury. Reactive oxygen species (ROS) generation is involved in many cases. However, little is known about the mechanism of ROS formation from artemisinin derivatives and what types of ROS are produced. Therefore, we investigated the iron-induced ROS formation mechanism by using artesunate, a water-soluble artemisinin derivative, which is thought to be the underlying mechanism involved in artesunate-mediated cell death. The ROS generated by the coexistence of iron(II), artesunate, and molecular oxygen was a hydroxyl radical or hydroxyl radical-like ROS. Artesunate can reduce iron(III) to iron(II), which enables generation of ROS irrespective of the iron valence. We found that reduction from iron(III) to iron(II) was activated in the acidic rather than the neutral region and was proportional to the hydrogen ion concentration.
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Affiliation(s)
- Katsunori Tsuda
- Department of Medical Pharmacology, Institute of Biomedical Sciences, University of Tokushima Graduate School
| | - Licht Miyamoto
- Department of Medical Pharmacology, Institute of Biomedical Sciences, University of Tokushima Graduate School
| | - Shuichi Hamano
- Department of Cell and Immunity Analytics, Institute of Biomedical Sciences, University of Tokushima Graduate School
| | - Yuri Morimoto
- Major in Laboratory Science, School of Health Sciences, Faculty of Medicine, Tokushima University
| | - Yumi Kangawa
- Major in Laboratory Science, School of Health Sciences, Faculty of Medicine, Tokushima University
| | - Chika Fukue
- Major in Laboratory Science, School of Health Sciences, Faculty of Medicine, Tokushima University
| | - Yoko Kagawa
- Major in Laboratory Science, School of Health Sciences, Faculty of Medicine, Tokushima University
| | - Yuya Horinouchi
- Department of Pharmacology, Institute of Biomedical Sciences, University of Tokushima Graduate School
| | - Wenting Xu
- Department of Medical Pharmacology, Institute of Biomedical Sciences, University of Tokushima Graduate School
| | - Yasumasa Ikeda
- Department of Pharmacology, Institute of Biomedical Sciences, University of Tokushima Graduate School
| | - Toshiaki Tamaki
- Department of Pharmacology, Institute of Biomedical Sciences, University of Tokushima Graduate School
| | - Koichiro Tsuchiya
- Department of Medical Pharmacology, Institute of Biomedical Sciences, University of Tokushima Graduate School
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Safety Experience During Real-World Use of Injectable Artesunate in Public Health Facilities in Ghana and Uganda: Outcomes of a Modified Cohort Event Monitoring Study (CEMISA). Drug Saf 2018; 41:871-880. [PMID: 29696507 PMCID: PMC6061362 DOI: 10.1007/s40264-018-0667-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Introduction Injectable artesunate (Inj AS) is the World Health Organization (WHO)-recommended product for treating severe malaria. However, despite widespread usage, there are few published safety studies involving large populations in real-world settings. In this study, we sought to assess the incidence of common adverse events (AEs) following the intake of Inj AS in real-life settings. Methods This is a modified cohort event monitoring study involving patients who were administered with Inj AS at eight sites (four each in Ghana and Uganda) between May and December 2016. Patients were eligible for inclusion if they had severe/complicated malaria and were able and willing to participate in the study. Eligible patients were followed up by telephone or hospital or home visit on Days 7, 14, 21 and 28 after drug administration to document AEs and serious AEs (SAEs). Patients were also encouraged to report all AEs at any time during the study period. The Kaplan–Meier method was used to estimate the proportion of patients with any AEs by end of Day 28. Causality assessment was made on all AEs/SAEs using the WHO/UMC (Uppsala Monitoring Centre) causality method. Results A total of 1103 eligible patients were administered Inj AS, of which 360 patients were in Ghana and 743 in Uganda. The incidence of any AE by the end of follow-up among patients treated with AS was estimated to be 17.9% (197/1103) (95% confidence interval [CI] 15.8–20.3). The median time-to-onset of any AEs was 9 days (interquartile range (IQR) = 4, 14). The top five AEs recorded among patients treated with AS were pyrexia (3.5%), abdominal pain (2.5%), diarrhoea (1.7%), cough (1.5%) and asthenia (1.5%). Most of these top five AEs occurred in the first 14 days following treatment. Regarding the relatedness of these AEs to Inj AS, 78.9% of pyrexia (30/38), 63.0% of pain (17/27), 68.4% of diarrhoea (13/19), 85.5% of cough (14/16) and 75.0% of asthenia (12/16) were assessed as ‘possibly’ related. There were 17 SAEs including 13 deaths. Two of the deaths are ‘possibly’ related to Inj AS, as were three non-fatal SAEs: severe abdominal pain, failure of therapy and severe anaemia. Conclusion The incidence of common AEs among patients treated with Inj AS in real-world settings was found to be relatively low. Future studies should consider larger cohorts to document rare AEs as well. ClinicalTrials.gov Identifier NCT02817919.
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Burrows JN, Duparc S, Gutteridge WE, Hooft van Huijsduijnen R, Kaszubska W, Macintyre F, Mazzuri S, Möhrle JJ, Wells TNC. New developments in anti-malarial target candidate and product profiles. Malar J 2017; 16:26. [PMID: 28086874 PMCID: PMC5237200 DOI: 10.1186/s12936-016-1675-x] [Citation(s) in RCA: 313] [Impact Index Per Article: 44.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2016] [Accepted: 12/30/2016] [Indexed: 11/10/2022] Open
Abstract
A decade of discovery and development of new anti-malarial medicines has led to a renewed focus on malaria elimination and eradication. Changes in the way new anti-malarial drugs are discovered and developed have led to a dramatic increase in the number and diversity of new molecules presently in pre-clinical and early clinical development. The twin challenges faced can be summarized by multi-drug resistant malaria from the Greater Mekong Sub-region, and the need to provide simplified medicines. This review lists changes in anti-malarial target candidate and target product profiles over the last 4 years. As well as new medicines to treat disease and prevent transmission, there has been increased focus on the longer term goal of finding new medicines for chemoprotection, potentially with long-acting molecules, or parenteral formulations. Other gaps in the malaria armamentarium, such as drugs to treat severe malaria and endectocides (that kill mosquitoes which feed on people who have taken the drug), are defined here. Ultimately the elimination of malaria requires medicines that are safe and well-tolerated to be used in vulnerable populations: in pregnancy, especially the first trimester, and in those suffering from malnutrition or co-infection with other pathogens. These updates reflect the maturing of an understanding of the key challenges in producing the next generation of medicines to control, eliminate and ultimately eradicate malaria.
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Affiliation(s)
- Jeremy N Burrows
- Medicines for Malaria Venture, Route de Pré Bois 20, 1215, Geneva 15, Switzerland
| | - Stephan Duparc
- Medicines for Malaria Venture, Route de Pré Bois 20, 1215, Geneva 15, Switzerland
| | | | | | - Wiweka Kaszubska
- Medicines for Malaria Venture, Route de Pré Bois 20, 1215, Geneva 15, Switzerland
| | - Fiona Macintyre
- Medicines for Malaria Venture, Route de Pré Bois 20, 1215, Geneva 15, Switzerland
| | | | - Jörg J Möhrle
- Medicines for Malaria Venture, Route de Pré Bois 20, 1215, Geneva 15, Switzerland
| | - Timothy N C Wells
- Medicines for Malaria Venture, Route de Pré Bois 20, 1215, Geneva 15, Switzerland.
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Kremsner PG, Adegnika AA, Hounkpatin AB, Zinsou JF, Taylor TE, Chimalizeni Y, Liomba A, Kombila M, Bouyou-Akotet MK, Mawili Mboumba DP, Agbenyega T, Ansong D, Sylverken J, Ogutu BR, Otieno GA, Wangwe A, Bojang KA, Okomo U, Sanya-Isijola F, Newton CR, Njuguna P, Kazungu M, Kerb R, Geditz M, Schwab M, Velavan TP, Nguetse C, Köhler C, Issifou S, Bolte S, Engleitner T, Mordmüller B, Krishna S. Intramuscular Artesunate for Severe Malaria in African Children: A Multicenter Randomized Controlled Trial. PLoS Med 2016; 13:e1001938. [PMID: 26757276 PMCID: PMC4710539 DOI: 10.1371/journal.pmed.1001938] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/16/2015] [Accepted: 12/02/2015] [Indexed: 11/18/2022] Open
Abstract
BACKGROUND Current artesunate (ARS) regimens for severe malaria are complex. Once daily intramuscular (i.m.) injection for 3 d would be simpler and more appropriate for remote health facilities than the current WHO-recommended regimen of five intravenous (i.v.) or i.m. injections over 4 d. We compared both a three-dose i.m. and a three-dose i.v. parenteral ARS regimen with the standard five-dose regimen using a non-inferiority design (with non-inferiority margins of 10%). METHODS AND FINDINGS This randomized controlled trial included children (0.5-10 y) with severe malaria at seven sites in five African countries to assess whether the efficacy of simplified three-dose regimens is non-inferior to a five-dose regimen. We randomly allocated 1,047 children to receive a total dose of 12 mg/kg ARS as either a control regimen of five i.m. injections of 2.4 mg/kg (at 0, 12, 24, 48, and 72 h) (n = 348) or three injections of 4 mg/kg (at 0, 24, and 48 h) either i.m. (n = 348) or i.v. (n = 351), both of which were the intervention arms. The primary endpoint was the proportion of children with ≥ 99% reduction in parasitemia at 24 h from admission values, measured by microscopists who were blinded to the group allocations. Primary analysis was performed on the per-protocol population, which was 96% of the intention-to-treat population. Secondary analyses included an analysis of host and parasite genotypes as risks for prolongation of parasite clearance kinetics, measured every 6 h, and a Kaplan-Meier analysis to compare parasite clearance kinetics between treatment groups. A post hoc analysis was performed for delayed anemia, defined as hemoglobin ≤ 7 g/dl 7 d or more after admission. The per-protocol population was 1,002 children (five-dose i.m.: n = 331; three-dose i.m.: n = 338; three-dose i.v.: n = 333); 139 participants were lost to follow-up. In the three-dose i.m. arm, 265/338 (78%) children had a ≥ 99% reduction in parasitemia at 24 h compared to 263/331 (79%) receiving the five-dose i.m. regimen, showing non-inferiority of the simplified three-dose regimen to the conventional five-dose regimen (95% CI -7, 5; p = 0.02). In the three-dose i.v. arm, 246/333 (74%) children had ≥ 99% reduction in parasitemia at 24 h; hence, non-inferiority of this regimen to the five-dose control regimen was not shown (95% CI -12, 1; p = 0.24). Delayed parasite clearance was associated with the N86YPfmdr1 genotype. In a post hoc analysis, 192/885 (22%) children developed delayed anemia, an adverse event associated with increased leukocyte counts. There was no observed difference in delayed anemia between treatment arms. A potential limitation of the study is its open-label design, although the primary outcome measures were assessed in a blinded manner. CONCLUSIONS A simplified three-dose i.m. regimen for severe malaria in African children is non-inferior to the more complex WHO-recommended regimen. Parenteral ARS is associated with a risk of delayed anemia in African children. TRIAL REGISTRATION Pan African Clinical Trials Registry PACTR201102000277177.
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Affiliation(s)
- Peter G. Kremsner
- Institut für Tropenmedizin, Eberhard Karls Universität Tübingen, Tübingen, Germany
- Centre de Recherches Médicales de Lambaréné, Hôpital Albert Schweitzer, Lambaréné, Gabon
- * E-mail: (PGK); (SK)
| | - Akim A. Adegnika
- Institut für Tropenmedizin, Eberhard Karls Universität Tübingen, Tübingen, Germany
- Centre de Recherches Médicales de Lambaréné, Hôpital Albert Schweitzer, Lambaréné, Gabon
| | - Aurore B. Hounkpatin
- Institut für Tropenmedizin, Eberhard Karls Universität Tübingen, Tübingen, Germany
- Centre de Recherches Médicales de Lambaréné, Hôpital Albert Schweitzer, Lambaréné, Gabon
| | - Jeannot F. Zinsou
- Institut für Tropenmedizin, Eberhard Karls Universität Tübingen, Tübingen, Germany
- Centre de Recherches Médicales de Lambaréné, Hôpital Albert Schweitzer, Lambaréné, Gabon
| | - Terrie E. Taylor
- Blantyre Malaria Project, University of Malawi College of Medicine, Blantyre, Malawi
| | - Yamikani Chimalizeni
- Blantyre Malaria Project, University of Malawi College of Medicine, Blantyre, Malawi
| | - Alice Liomba
- Blantyre Malaria Project, University of Malawi College of Medicine, Blantyre, Malawi
| | - Maryvonne Kombila
- Department of Parasitology Mycology, Faculty of Medicine, Université des Sciences de la Santé, Libreville, Gabon
| | - Marielle K. Bouyou-Akotet
- Department of Parasitology Mycology, Faculty of Medicine, Université des Sciences de la Santé, Libreville, Gabon
| | - Denise P. Mawili Mboumba
- Department of Parasitology Mycology, Faculty of Medicine, Université des Sciences de la Santé, Libreville, Gabon
| | - Tsiri Agbenyega
- Department of Physiology, University of Science and Technology, School of Medical Sciences, Kumasi, Ghana
- Departments of Child Health and Medicine, Komfo Anokye Teaching Hospital, Kumasi, Ghana
| | - Daniel Ansong
- Department of Physiology, University of Science and Technology, School of Medical Sciences, Kumasi, Ghana
- Departments of Child Health and Medicine, Komfo Anokye Teaching Hospital, Kumasi, Ghana
| | - Justice Sylverken
- Department of Physiology, University of Science and Technology, School of Medical Sciences, Kumasi, Ghana
- Departments of Child Health and Medicine, Komfo Anokye Teaching Hospital, Kumasi, Ghana
| | - Bernhards R. Ogutu
- Centre for Clinical Research, Kenya Medical Research Institute, Kisumu, Kenya
| | - Godfrey A. Otieno
- Centre for Clinical Research, Kenya Medical Research Institute, Kisumu, Kenya
| | - Anne Wangwe
- Centre for Clinical Research, Kenya Medical Research Institute, Kisumu, Kenya
| | | | - Uduak Okomo
- Medical Research Council Laboratories, Fajara, The Gambia
| | | | - Charles R. Newton
- Centre for Geographic Medicine Research–Coast, Kenya Medical Research Institute, Kilifi, Kenya
| | - Patricia Njuguna
- Centre for Geographic Medicine Research–Coast, Kenya Medical Research Institute, Kilifi, Kenya
| | - Michael Kazungu
- Centre for Geographic Medicine Research–Coast, Kenya Medical Research Institute, Kilifi, Kenya
| | - Reinhold Kerb
- Dr. Margarete Fischer-Bosch-Institut für Klinische Pharmakologie, Stuttgart, Germany
- Eberhard Karls Universität Tübingen, Tübingen, Germany
| | - Mirjam Geditz
- Dr. Margarete Fischer-Bosch-Institut für Klinische Pharmakologie, Stuttgart, Germany
- Eberhard Karls Universität Tübingen, Tübingen, Germany
| | - Matthias Schwab
- Dr. Margarete Fischer-Bosch-Institut für Klinische Pharmakologie, Stuttgart, Germany
- Abteilung Klinische Pharmakologie, Universitätsklinikum Tübingen, Tübingen, Germany
| | | | - Christian Nguetse
- Institut für Tropenmedizin, Eberhard Karls Universität Tübingen, Tübingen, Germany
| | - Carsten Köhler
- Institut für Tropenmedizin, Eberhard Karls Universität Tübingen, Tübingen, Germany
| | - Saadou Issifou
- Institut für Tropenmedizin, Eberhard Karls Universität Tübingen, Tübingen, Germany
- Centre de Recherches Médicales de Lambaréné, Hôpital Albert Schweitzer, Lambaréné, Gabon
| | - Stefanie Bolte
- Institut für Tropenmedizin, Eberhard Karls Universität Tübingen, Tübingen, Germany
| | - Thomas Engleitner
- Institut für Tropenmedizin, Eberhard Karls Universität Tübingen, Tübingen, Germany
| | - Benjamin Mordmüller
- Institut für Tropenmedizin, Eberhard Karls Universität Tübingen, Tübingen, Germany
- Centre de Recherches Médicales de Lambaréné, Hôpital Albert Schweitzer, Lambaréné, Gabon
| | - Sanjeev Krishna
- Institut für Tropenmedizin, Eberhard Karls Universität Tübingen, Tübingen, Germany
- Centre de Recherches Médicales de Lambaréné, Hôpital Albert Schweitzer, Lambaréné, Gabon
- Institute for Infection and Immunity, St George’s, University of London, London, United Kingdom
- * E-mail: (PGK); (SK)
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Twomey PS, Smith BL, McDermott C, Novitt-Moreno A, McCarthy W, Kachur SP, Arguin PM. Intravenous Artesunate for the Treatment of Severe and Complicated Malaria in the United States: Clinical Use Under an Investigational New Drug Protocol. Ann Intern Med 2015; 163:498-506. [PMID: 26301474 PMCID: PMC4627466 DOI: 10.7326/m15-0910] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
BACKGROUND Quinidine gluconate, the only U.S. Food and Drug Administration-approved treatment for life-threatening malaria in the United States, has a problematic safety profile and is often unavailable in hospitals. OBJECTIVE To assess the safety and clinical benefit of intravenous artesunate as an alternative to quinidine. DESIGN Retrospective case series. SETTING U.S. hospitals. PATIENTS 102 patients aged 1 to 72 years (90% adults; 61% men) with severe and complicated malaria. Patients received 4 weight-based doses of intravenous artesunate (2.4 mg/kg) under a treatment protocol implemented by the Centers for Disease Control and Prevention between January 2007 and December 2010. At baseline, 35% had evidence of cerebral malaria, and 17% had severe hepatic impairment. Eligibility required the presence of microscopically confirmed malaria, need for intravenous treatment, and an impediment to quinidine. MEASUREMENTS Clinical and laboratory data from each patient's hospital records were abstracted retrospectively, including information from baseline through a maximum 7-day follow-up, and presented before a physician committee to evaluate safety and clinical benefit outcomes. RESULTS 7 patients died (mortality rate, 6.9%). The most frequent adverse events were anemia (65%) and elevated hepatic enzyme levels (49%). All deaths and most adverse events were attributed to the severity of malaria. Patients' symptoms generally improved or resolved within 3 days, and the median time to discharge from the intensive care unit was 4 days, even for patients with severe liver disease or cerebral malaria. More than 100 concomitant medications were used, with no documented drug-drug interactions. LIMITATION Potential late-presenting safety issues might occur outside the 7-day follow-up. CONCLUSION Artesunate was a safe and clinically beneficial alternative to quinidine.
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Affiliation(s)
- Patrick S. Twomey
- From U.S. Army Medical Materiel Development Activity, Fort Detrick; Fast-Track Drugs and Biologics, North Potomac; and Centers for Disease Control and Prevention, Bethesda, Maryland
| | - Bryan L. Smith
- From U.S. Army Medical Materiel Development Activity, Fort Detrick; Fast-Track Drugs and Biologics, North Potomac; and Centers for Disease Control and Prevention, Bethesda, Maryland
| | - Cathy McDermott
- From U.S. Army Medical Materiel Development Activity, Fort Detrick; Fast-Track Drugs and Biologics, North Potomac; and Centers for Disease Control and Prevention, Bethesda, Maryland
| | - Anne Novitt-Moreno
- From U.S. Army Medical Materiel Development Activity, Fort Detrick; Fast-Track Drugs and Biologics, North Potomac; and Centers for Disease Control and Prevention, Bethesda, Maryland
| | - William McCarthy
- From U.S. Army Medical Materiel Development Activity, Fort Detrick; Fast-Track Drugs and Biologics, North Potomac; and Centers for Disease Control and Prevention, Bethesda, Maryland
| | - S. Patrick Kachur
- From U.S. Army Medical Materiel Development Activity, Fort Detrick; Fast-Track Drugs and Biologics, North Potomac; and Centers for Disease Control and Prevention, Bethesda, Maryland
| | - Paul M. Arguin
- From U.S. Army Medical Materiel Development Activity, Fort Detrick; Fast-Track Drugs and Biologics, North Potomac; and Centers for Disease Control and Prevention, Bethesda, Maryland
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Hawkes MT, Forgie S, Brophy J, Crockett M. Artesunate treatment of severe pediatric malaria: A review of parasite clearance kinetics and clinical implications. THE CANADIAN JOURNAL OF INFECTIOUS DISEASES & MEDICAL MICROBIOLOGY = JOURNAL CANADIEN DES MALADIES INFECTIEUSES ET DE LA MICROBIOLOGIE MEDICALE 2015; 26:237-40. [PMID: 26600806 PMCID: PMC4644001 DOI: 10.1155/2015/736159] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Affiliation(s)
- Michael T Hawkes
- Department of Pediatrics, University of Alberta, Edmonton, Alberta
- School of Public Health, University of Alberta, Edmonton, Alberta
- Department of Medical Microbiology and Immunology, University of Alberta, Edmonton, Alberta
| | - Sarah Forgie
- Department of Pediatrics, University of Alberta, Edmonton, Alberta
| | - Jason Brophy
- Department of Pediatrics, Children’s Hospital of Eastern Ontario, Ottawa, Ontario
| | - Maryanne Crockett
- Departments of Pediatrics and Child Health, Medical Microbiology and Community Health Sciences, University of Manitoba, Winnipeg, Manitoba
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A Randomised, Double Blind, Placebo-Controlled Pilot Study of Oral Artesunate Therapy for Colorectal Cancer. EBioMedicine 2014; 2:82-90. [PMID: 26137537 PMCID: PMC4484515 DOI: 10.1016/j.ebiom.2014.11.010] [Citation(s) in RCA: 133] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2014] [Revised: 11/13/2014] [Accepted: 11/13/2014] [Indexed: 12/21/2022] Open
Abstract
BACKGROUND Artesunate is an antimalarial agent with broad anti-cancer activity in in vitro and animal experiments and case reports. Artesunate has not been studied in rigorous clinical trials for anticancer effects. AIM To determine the anticancer effect and tolerability of oral artesunate in colorectal cancer (CRC). METHODS This was a single centre, randomised, double-blind, placebo-controlled trial. Patients planned for curative resection of biopsy confirmed single primary site CRC were randomised (n = 23) by computer-generated code supplied in opaque envelopes to receive preoperatively either 14 daily doses of oral artesunate (200 mg; n = 12) or placebo (n = 11). The primary outcome measure was the proportion of tumour cells undergoing apoptosis (significant if > 7% showed Tunel staining). Secondary immunohistochemical outcomes assessed these tumour markers: VEGF, EGFR, c-MYC, CD31, Ki67 and p53, and clinical responses. FINDINGS 20 patients (artesunate = 9, placebo = 11) completed the trial per protocol. Randomization groups were comparable clinically and for tumour characteristics. Apoptosis in > 7% of cells was seen in 67% and 55% of patients in artesunate and placebo groups, respectively. Using Bayesian analysis, the probabilities of an artesunate treatment effect reducing Ki67 and increasing CD31 expression were 0.89 and 0.79, respectively. During a median follow up of 42 months 1 patient in the artesunate and 6 patients in the placebo group developed recurrent CRC. INTERPRETATION Artesunate has anti-proliferative properties in CRC and is generally well tolerated.
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Zaloumis SG, Tarning J, Krishna S, Price RN, White NJ, Davis TME, McCaw JM, Olliaro P, Maude RJ, Kremsner P, Dondorp A, Gomes M, Barnes K, Simpson JA. Population pharmacokinetics of intravenous artesunate: a pooled analysis of individual data from patients with severe malaria. CPT-PHARMACOMETRICS & SYSTEMS PHARMACOLOGY 2014; 3:e145. [PMID: 25372510 PMCID: PMC4259998 DOI: 10.1038/psp.2014.43] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/03/2014] [Accepted: 08/28/2014] [Indexed: 11/09/2022]
Abstract
There are ~660,000 deaths from severe malaria each year. Intravenous artesunate (i.v. ARS) is the first-line treatment in adults and children. To optimize the dosing regimen of i.v. ARS, the largest pooled population pharmacokinetic study to date of the active metabolite dihydroartemisinin (DHA) was performed. The pooled dataset consisted of 71 adults and 195 children with severe malaria, with a mixture of sparse and rich sampling within the first 12 h after drug administration. A one-compartment model described the population pharmacokinetics of DHA adequately. Body weight had the greatest impact on DHA pharmacokinetics, resulting in lower DHA exposure for smaller children (6–10 kg) than adults. Post hoc estimates of DHA exposure were not significantly associated with parasitological outcomes. Comparable DHA exposure in smaller children and adults after i.v. ARS was achieved under a dose modification for intramuscular ARS proposed in a separate analysis of children.
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Affiliation(s)
- S G Zaloumis
- Centre for Epidemiology and Biostatistics, Melbourne School of Population and Global Health, University of Melbourne, Melbourne, Australia
| | - J Tarning
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - S Krishna
- Institute for Infection and Immunity, St. George's, University of London, London, UK
| | - R N Price
- Centre for Clinical Vaccinology and Tropical Medicine, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - N J White
- 1] Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand [2] Centre for Tropical Medicine, Nuffield Department of Clinical Medicine, University of Oxford, Oxford, UK
| | - T M E Davis
- School of Medicine and Pharmacology, Fremantle Hospital, University of Western Australia, Fremantle, Australia
| | - J M McCaw
- Centre for Epidemiology and Biostatistics, Melbourne School of Population and Global Health, University of Melbourne, Melbourne, Australia
| | - P Olliaro
- 1] Centre for Tropical Medicine, Nuffield Department of Clinical Medicine, University of Oxford, Oxford, UK [2] World Health Organization, Genève, Switzerland
| | - R J Maude
- 1] Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand [2] Centre for Tropical Medicine, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - P Kremsner
- 1] Medical Research Unit, Albert Schweitzer Hospital, Lambaréné, Gabon [2] Institute for Tropical Medicine, Department of Parasitology, University of Tübingen, Tübingen, Germany
| | - A Dondorp
- 1] Centre for Tropical Medicine, Nuffield Department of Clinical Medicine, University of Oxford, Oxford, UK [2] Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - M Gomes
- World Health Organization, Genève, Switzerland
| | - K Barnes
- Division of Clinical Pharmacology, Department of Medicine, University of Cape Town, Cape Town, South Africa
| | - J A Simpson
- Centre for Epidemiology and Biostatistics, Melbourne School of Population and Global Health, University of Melbourne, Melbourne, Australia
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Haemolysis associated with the treatment of malaria with artemisinin derivatives: a systematic review of current evidence. Int J Infect Dis 2014; 29:268-73. [PMID: 25448338 DOI: 10.1016/j.ijid.2014.09.007] [Citation(s) in RCA: 62] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2014] [Revised: 08/13/2014] [Accepted: 09/04/2014] [Indexed: 11/22/2022] Open
Abstract
BACKGROUND Artemisinin derivatives are the mainstay of antimalarial treatment, both for uncomplicated malaria and for severe disease. Artemisinins are known for their rapid onset of action, good tolerability, and safety. However, besides the sporadic but worrying reports of delayed parasite clearance after treatment with artemisinins, there have been an increasing number of reports of acute haemolytic anaemia following their use and the safety of this class of antimalarials is being questioned. METHODS In this systematic review, all reports of patients experiencing haemolysis following the use of artemisinins for the treatment of malaria were identified and collated into an electronic database. Summary statistics were calculated to characterize the epidemiology and clinical features of this safety concern related to artemisinin derivatives. RESULTS A total of 37 patients were identified suffering from haemolysis following the treatment of severe malaria with artemisinin derivatives. Thirty-one cases had received intravenous artesunate, while the remaining cases were attributed to other parenteral or oral regimens of artemisinin derivatives. The majority of patients were returning travellers (n=30), and six clinical cases had been reported in paediatric patients. The median onset of haemolysis was 15 (interquartile range (IQR) 13-15) days after the initiation of treatment for the 'delayed-onset' pattern and 17 (IQR 13-22) days for the 'persistent' haemolysis pattern. The median reduction in haemoglobin due to haemolysis was 6 g/dl (IQR 4-8 g/dl). The estimated proportion of patients suffering from severe malaria experiencing haemolysis after treatment with artemisinin derivatives was 13% (95% confidence interval 9-18%), and 73% of these (i.e., 9% of the total population) required blood transfusions. No fatal outcome has been reported in the literature to date. CONCLUSIONS Haemolysis is commonly associated with the class of artemisinin drugs when used for the treatment of severe malaria. Potential causes of this safety issue are discussed. Although no deaths attributed to haemolysis have been reported so far, this safety issue may lead to life-threatening anaemia and is particularly worrying for regions where safe blood products are not readily available.
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Krishna S, Pulcini S, Moore CM, Teo BHY, Staines HM. Pumped up: reflections on PfATP6 as the target for artemisinins. Trends Pharmacol Sci 2014; 35:4-11. [DOI: 10.1016/j.tips.2013.10.007] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2013] [Revised: 10/11/2013] [Accepted: 10/21/2013] [Indexed: 12/01/2022]
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Rolling T, Agbenyega T, Issifou S, Adegnika AA, Sylverken J, Spahlinger D, Ansong D, Löhr SJZ, Burchard GD, May J, Mordmüller B, Krishna S, Kremsner PG, Cramer JP. Delayed hemolysis after treatment with parenteral artesunate in African children with severe malaria--a double-center prospective study. J Infect Dis 2013; 209:1921-8. [PMID: 24376273 DOI: 10.1093/infdis/jit841] [Citation(s) in RCA: 70] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
BACKGROUND Parenteral artesunate is recommended as first-line therapy for severe malaria. While its efficacy is firmly established, data on safety are still incomplete. Delayed hemolysis has been described in hyperparasitemic nonimmune travelers, but it is unknown if African children are equally at risk. METHODS Children aged 6 to 120 months with severe malaria were followed up after treatment with parenteral artesunate in Lambaréné, Gabon, and Kumasi, Ghana. The primary outcome was incidence of delayed hemolysis on day 14. RESULTS In total, 72 children contributed complete data sets necessary for primary outcome assessment. Delayed hemolysis was detected in 5 children (7%), with 1 child reaching a nadir in hemoglobin of 2.8 g/dL. Patients with delayed hemolysis had higher parasite counts on admission (geometric mean parasite densities (GMPD) 306 968/µL vs 92 642/µL, P = .028) and were younger (median age: 24 months vs 43 months, P = .046) than the rest of the cohort. No correlation with sickle cell trait or glucose-6-phosphate-dehydrogenase deficiency was observed. CONCLUSIONS Delayed hemolysis is a frequent and relevant complication in hyperparasitemic African children treated with parenteral artesunate for severe malaria. Physicians should be aware of this complication and consider prolonged follow-up. CLINICAL TRIALS REGISTRATION Pan-African Clinical Trials Registry: PACTR201102000277177 (www.pactr.org).
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Affiliation(s)
- Thierry Rolling
- Department of Internal Medicine I, Section Tropical Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany Department of Clinical Research, Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany Centre de Recherches Médicales de Lambaréné, Gabon
| | - Tsiri Agbenyega
- School of Medical Sciences, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana
| | - Saadou Issifou
- Centre de Recherches Médicales de Lambaréné, Gabon Institute of Tropical Medicine, University Medical Center Tübingen, Tübingen, Germany
| | - Ayola Akim Adegnika
- Centre de Recherches Médicales de Lambaréné, Gabon Institute of Tropical Medicine, University Medical Center Tübingen, Tübingen, Germany
| | - Justice Sylverken
- School of Medical Sciences, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana Paediatric Emergency Unit, Department of Child Health, Komfo Anokye Teaching Hospital, Kumasi, Ghana
| | - Dorothee Spahlinger
- Department of Internal Medicine I, Section Tropical Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany Department of Clinical Research, Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany
| | - Daniel Ansong
- School of Medical Sciences, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana Paediatric Emergency Unit, Department of Child Health, Komfo Anokye Teaching Hospital, Kumasi, Ghana
| | - Sascha J Z Löhr
- Centre de Recherches Médicales de Lambaréné, Gabon Institute of Tropical Medicine, University Medical Center Tübingen, Tübingen, Germany
| | - Gerd D Burchard
- Department of Internal Medicine I, Section Tropical Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany Department of Clinical Research, Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany
| | - Jürgen May
- Infectious Disease Epidemiology, Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany
| | - Benjamin Mordmüller
- Centre de Recherches Médicales de Lambaréné, Gabon Institute of Tropical Medicine, University Medical Center Tübingen, Tübingen, Germany
| | - Sanjeev Krishna
- Centre de Recherches Médicales de Lambaréné, Gabon Institute of Tropical Medicine, University Medical Center Tübingen, Tübingen, Germany Centre for Infection and Immunity, Division of Clinical Sciences, St. George's, University of London, London, United Kingdom
| | - Peter G Kremsner
- Centre de Recherches Médicales de Lambaréné, Gabon Institute of Tropical Medicine, University Medical Center Tübingen, Tübingen, Germany
| | - Jakob P Cramer
- Department of Internal Medicine I, Section Tropical Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany Department of Clinical Research, Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany
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Held J, Kreidenweiss A, Mordmüller B. Novel approaches in antimalarial drug discovery. Expert Opin Drug Discov 2013; 8:1325-37. [PMID: 24090219 DOI: 10.1517/17460441.2013.843522] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
INTRODUCTION The development of new antimalarial drugs remains of the utmost importance, since Plasmodium falciparum has developed resistance against nearly all chemotherapeutics in clinical use. In an effort to contain the resistance of P. falciparum against artemisinins and to further eradication efforts, studies are ongoing to identify novel and more efficacious approaches to develop antimalarials. AREAS COVERED The authors review the classical and new approaches to antimalarial drug discovery, with a special emphasis on the various stages of the parasite's life cycle and the different Plasmodium species. The authors discuss the methodologies and strategies for early efficacy testing that aim to narrow down the portfolio of promising compounds. EXPERT OPINION The increased efforts in the discovery and development of new antimalarial compounds have led to the recognition of new promising hits. However, there is still major roadblock of selecting the most promising compounds and then further testing them in early clinical trials, especially in the current restricted economy. Controlled human malaria infection has much potential for speeding-up the early development process of many drug candidates including those which target the pre-erythrocytic stages.
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Affiliation(s)
- Jana Held
- University of Tübingen, Institute of Tropical Medicine , Wilhelmstraße 27, D-72074 Tübingen , Germany +49 7071 29 82364 ; +49 7071 295189 ;
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25
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Krishna S, Kremsner PG. Artemisinin resistance needs to be defined rigorously to be understood: response to Dondorp and Ringwald. Trends Parasitol 2013; 29:361-2. [DOI: 10.1016/j.pt.2013.05.006] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2013] [Accepted: 05/30/2013] [Indexed: 01/03/2023]
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Krishna S, Kremsner PG. Antidogmatic approaches to artemisinin resistance: reappraisal as treatment failure with artemisinin combination therapy. Trends Parasitol 2013; 29:313-7. [PMID: 23623760 DOI: 10.1016/j.pt.2013.04.001] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2013] [Revised: 03/29/2013] [Accepted: 04/01/2013] [Indexed: 11/17/2022]
Abstract
The definition of artemisinin resistance is becoming one of a prolonged parasite clearance phenotype, although this variable is a complex function of both host and parasite characteristics. We discuss some of the limitations of this definition of artemisinin resistance, particularly because of its potential global impact. This opinion article reviews the mechanisms underlying parasite clearance after artemisinin treatment and how these might relate to in vitro methods to assay for resistance. It revisits criteria for defining artemisinin resistance that are not currently being applied and suggests the term 'treatment failure of artemisinin combination therapy' (TFACT) as a more accurate description of most cases of 'artemisinin resistance'.
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Affiliation(s)
- Sanjeev Krishna
- Centre for Infection and Immunity, Division of Clinical Sciences, St George's, University of London, Cranmer Terrace, London SW17 0RE, UK.
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27
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Ex vivo responses of Plasmodium falciparum clinical isolates to conventional and new antimalarial drugs in Niger. Antimicrob Agents Chemother 2013; 57:3415-9. [PMID: 23612203 DOI: 10.1128/aac.02383-12] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Little is known about resistance of Plasmodium falciparum to antimalarials in Sahelian countries. Here we investigated the drug susceptibilities of fresh isolates collected in Niger post-deployment of artemisinin-based combination therapies (ACTs). We found that the parasites remained highly susceptible to new (dihydroartemisinin, lumefantrine, pyronaridine, and piperaquine) and conventional (amodiaquine and chloroquine) antimalarial drugs. The introduction of ACTs in 2005 and their further deployment nationwide have therefore not resulted in a decrease in P. falciparum susceptibilities to these antimalarials.
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Population pharmacokinetics of intramuscular artesunate in African children with severe malaria: implications for a practical dosing regimen. Clin Pharmacol Ther 2013; 93:443-50. [PMID: 23511715 PMCID: PMC3630454 DOI: 10.1038/clpt.2013.26] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Parenteral artesunate (ARS) is the drug of choice for the treatment of severe malaria. Pharmacokinetics data on intramuscular ARS are limited with respect to the main treatment group that carries the highest mortality, namely, critically ill children with severe malaria. A population pharmacokinetic study of ARS and dihydroartemisinin (DHA) was conducted from sparse sampling in 70 Tanzanian children of ages 6 months to 11 years. All the children had been admitted with severe falciparum malaria and were treated with intramuscular ARS (2.4 mg/kg at 0, 12, and 24 h). Venous plasma concentration-time profiles were characterized using nonlinear mixed-effects modeling (NONMEM). A one-compartment disposition model accurately described first-dose population pharmacokinetics of ARS and DHA. Body weight significantly affected clearance and apparent volume of distribution (P < 0.001), resulting in lower ARS and DHA exposure levels in smaller children. An adapted dosing regimen including a practical dosing table per weight band is proposed for young children based on the pharmacokinetic model.
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29
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Abstract
PURPOSE OF REVIEW Artesunate treatment reduces mortality in severe malaria when compared with quinine. Nevertheless, severe malaria is associated with mortality rates between 1.4 and 9.5% after hospitalization. This review puts into context the recent developments in understanding the pathophysiology of malaria and how these may be reflected in renewed attempts at improving adjunct therapies. Identifying new adjunct approaches has been particularly difficult for severe malaria because most interventions have either caused harm or failed to confer benefit. RECENT FINDINGS Imaging and postmortem findings in children with severe and cerebral malaria have given impetus to study new interventions that could be added to antimalarial treatment. Some pilot studies have (re)tested different approaches to improve complications of cerebral malaria such as the use of N-acetyl cysteine or mannitol. Fluids administration, blood transfusions and red cell exchanges in severe malaria are controversial and important areas that are also reviewed with new evidence. Other interventions such as measures to increase nitric oxide, manage acute renal failure or optimize artesunate dosing are discussed. SUMMARY Outcomes with adjunct therapies for severe malaria have been poor, but as insights into pathophysiological processes are deepened it may be possible eventually to reduce mortality further.
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30
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Kone A, Mu J, Maiga H, Beavogui AH, Yattara O, Sagara I, Tekete MM, Traore OB, Dara A, Dama S, Diallo N, Kodio A, Traoré A, Björkman A, Gil JP, Doumbo OK, Wellems TE, Djimde AA. Quinine treatment selects the pfnhe-1 ms4760-1 polymorphism in Malian patients with Falciparum malaria. J Infect Dis 2012; 207:520-7. [PMID: 23162138 DOI: 10.1093/infdis/jis691] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
BACKGROUND The mechanism of Plasmodium falciparum resistance to quinine is not known. In vitro quantitative trait loci mapping suggests involvement of a predicted P. falciparum sodium-hydrogen exchanger (pfnhe-1) on chromosome 13. METHODS We conducted prospective quinine efficacy studies in 2 villages, Kollé and Faladié, Mali. Cases of clinical malaria requiring intravenous therapy were treated with standard doses of quinine and followed for 28 days. Treatment outcomes were classified using modified World Health Organization protocols. Molecular markers of parasite polymorphisms were used to distinguish recrudescent parasites from new infections. The prevalence of pfnhe-1 ms4760-1 among parasites before versus after quinine treatment was determined by direct sequencing. RESULTS Overall, 163 patients were enrolled and successfully followed. Without molecular correction, the mean adequate clinical and parasitological response (ACPR) was 50.3% (n = 163). After polymerase chain reaction correction to account for new infections, the corrected ACPR was 100%. The prevalence of ms4760-1 increased significantly, from 26.2% (n = 107) before quinine treatment to 46.3% (n = 54) after therapy (P = .01). In a control sulfadoxine-pyrimethamine study, the prevalence of ms4760-1 was similar before and after treatment. CONCLUSIONS This study supports a role for pfnhe-1 in decreased susceptibility of P. falciparum to quinine in the field.
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Affiliation(s)
- Aminatou Kone
- Malaria Research and Training Center, Department of Epidemiology of Parasitic Diseases, Faculty of Medicine, Pharmacy, and Odonto-Stomatology, University of Science, Techniques and Technology, Bamako, Mali
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Woodrow CJ, Taylor WRJ. Reappraisal of the efficacy of a simplified artesunate regimen in falciparum malaria. J Infect Dis 2012; 206:619-21; author reply 622. [PMID: 22732918 PMCID: PMC3400643 DOI: 10.1093/infdis/jis390] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Affiliation(s)
- Charles J. Woodrow
- Mahidol-Oxford University Tropical Medicine Research Unit (MORU), Bangkok, Thailand
- University of Oxford, Centre for Tropical Medicine, CCVTM,Oxford, United Kingdom
| | - Walter R. J. Taylor
- Mahidol-Oxford University Tropical Medicine Research Unit (MORU), Bangkok, Thailand
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32
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Dondorp AM, Maude RJ, Hendriksen ICE, Day NP, White NJ. Artesunate dosing in severe falciparum malaria. J Infect Dis 2012; 206:618-9; author reply 622. [PMID: 22732917 PMCID: PMC3400642 DOI: 10.1093/infdis/jis389] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/03/2022] Open
Affiliation(s)
- Arjen M. Dondorp
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Rajthevee, Bangkok, Thailand
- Centre for Tropical Medicine, Nuffield Department of Clinical Medicine, CCVTM, University of Oxford,United Kingdom
| | - Richard J. Maude
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Rajthevee, Bangkok, Thailand
- Centre for Tropical Medicine, Nuffield Department of Clinical Medicine, CCVTM, University of Oxford,United Kingdom
| | - Ilse C. E. Hendriksen
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Rajthevee, Bangkok, Thailand
| | - Nicholas P. Day
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Rajthevee, Bangkok, Thailand
- Centre for Tropical Medicine, Nuffield Department of Clinical Medicine, CCVTM, University of Oxford,United Kingdom
| | - Nicholas J. White
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Rajthevee, Bangkok, Thailand
- Centre for Tropical Medicine, Nuffield Department of Clinical Medicine, CCVTM, University of Oxford,United Kingdom
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