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Achan J, Barry A, Leroy D, Kamara G, Duparc S, Kaszubska W, Gandhi P, Buffet B, Tshilab P, Ogutu B, Taylor T, Krishna S, Richardson N, Ramachandruni H, Rietveld H. Defining the next generation of severe malaria treatment: a target product profile. Malar J 2024; 23:174. [PMID: 38835069 DOI: 10.1186/s12936-024-04986-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2024] [Accepted: 05/14/2024] [Indexed: 06/06/2024] Open
Abstract
BACKGROUND Severe malaria is a life-threatening infection, particularly affecting children under the age of 5 years in Africa. Current treatment with parenteral artemisinin derivatives is highly efficacious. However, artemisinin partial resistance is widespread in Southeast Asia, resulting in delayed parasite clearance after therapy, and has emerged independently in South America, Oceania, and Africa. Hence, new treatments for severe malaria are needed, and it is prudent to define their characteristics now. This manuscript focuses on the target product profile (TPP) for new treatments for severe malaria. It also highlights preparedness when considering ways of protecting the utility of artemisinin-based therapies. TARGET PRODUCT PROFILE Severe malaria treatments must be highly potent, with rapid onset of antiparasitic activity to clear the infection as quickly as possible to prevent complications. They should also have a low potential for drug resistance selection, given the high parasite burden in patients with severe malaria. Combination therapies are needed to deter resistance selection and dissemination. Partner drugs which are approved for uncomplicated malaria treatment would provide the most rapid development pathway for combinations, though new candidate molecules should be considered. Artemisinin combination approaches to severe malaria would extend the lifespan of current therapy, but ideally, completely novel, non-artemisinin-based combination therapies for severe malaria should be developed. These should be advanced to at least phase 2 clinical trials, enabling rapid progression to patient use should current treatment fail clinically. New drug combinations for severe malaria should be available as injectable formulations for rapid and effective treatment, or as rectal formulations for pre-referral intervention in resource-limited settings. CONCLUSION Defining the TPP is a key step to align responses across the community to proactively address the potential for clinical failure of artesunate in severe malaria. In the shorter term, artemisinin-based combination therapies should be developed using approved or novel drugs. In the longer term, novel combination treatments should be pursued. Thus, this TPP aims to direct efforts to preserve the efficacy of existing treatments while improving care and outcomes for individuals affected by this life-threatening disease.
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Affiliation(s)
| | - Aïssata Barry
- Centre National de Recherche et de Formation sur le Paludisme, Ouagadougou, Burkina Faso
| | - Didier Leroy
- Medicines for Malaria Venture, Route de Pré-Bois 20, Post Box 1826, CH-1215, Geneva 15, Switzerland
| | - George Kamara
- Médecins Sans Frontières, Magburaka District Hospital, Freetown, Sierra Leone
| | - Stephan Duparc
- Medicines for Malaria Venture, Route de Pré-Bois 20, Post Box 1826, CH-1215, Geneva 15, Switzerland
| | - Wiweka Kaszubska
- Medicines for Malaria Venture, Route de Pré-Bois 20, Post Box 1826, CH-1215, Geneva 15, Switzerland
| | | | - Bénédicte Buffet
- Medicines for Malaria Venture, Route de Pré-Bois 20, Post Box 1826, CH-1215, Geneva 15, Switzerland
| | | | - Bernhards Ogutu
- Centre for Clinical Research, Kenya Medical Research Institute, Kisumu, Kenya
| | - Terrie Taylor
- Queen Elizabeth Central Hospital and Blantyre Malaria Project, Kamuzu University of Health Sciences, Blantyre, Malawi
| | - 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, St. George's University of London, London, UK
- St George's University Hospitals NHS Foundation Trust, London, UK
| | | | - Hanu Ramachandruni
- Medicines for Malaria Venture, Route de Pré-Bois 20, Post Box 1826, CH-1215, Geneva 15, Switzerland.
| | - Hans Rietveld
- Medicines for Malaria Venture, Route de Pré-Bois 20, Post Box 1826, CH-1215, Geneva 15, Switzerland.
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Miatmoko A, Octavia RT, Araki T, Annoura T, Sari R. Advancing liposome technology for innovative strategies against malaria. Saudi Pharm J 2024; 32:102085. [PMID: 38690211 PMCID: PMC11059525 DOI: 10.1016/j.jsps.2024.102085] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2023] [Accepted: 04/23/2024] [Indexed: 05/02/2024] Open
Abstract
This review discusses the potential of liposomes as drug delivery systems for antimalarial therapies. Malaria continues to be a significant cause of mortality and morbidity, particularly among children and pregnant women. Drug resistance due to patient non-compliance and troublesome side effects remains a significant challenge in antimalarial treatment. Liposomes, as targeted and efficient drug carriers, have garnered attention owing to their ability to address these issues. Liposomes encapsulate hydrophilic and/or hydrophobic drugs, thus providing comprehensive and suitable therapeutic drug delivery. Moreover, the potential of passive and active drug delivery enables drug concentration in specific target tissues while reducing adverse effects. However, successful liposome formulation is influenced by various factors, including drug physicochemical characteristics and physiological barriers encountered during drug delivery. To overcome these challenges, researchers have explored modifications in liposome nanocarriers to achieve efficient drug loading, controlled release, and system stability. Computational approaches have also been adopted to predict liposome system stability, membrane integrity, and drug-liposome interactions, improving formulation development efficiency. By leveraging computational methods, optimizing liposomal drug delivery systems holds promise for enhancing treatment efficacy and minimizing side effects in malaria therapy. This review consolidates the current understanding and highlights the potential of liposome strategies against malaria.
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Affiliation(s)
- Andang Miatmoko
- Department of Pharmaceutical Science, Faculty of Pharmacy, Universitas Airlangga, Campus C UNAIR Mulyorejo, Surabaya 60115, Indonesia
- Stem Cell Research and Development Center, Universitas Airlangga, 2 Floor Institute of Tropical Disease Building, Campus C UNAIR Mulyorejo, Surabaya 60115, Indonesia
- Nanotechnology and Drug Delivery System Research Group, Faculty of Pharmacy, Universitas Airlangga, Campus C UNAIR Mulyorejo, Surabaya 60115, Indonesia
| | - Rifda Tarimi Octavia
- Master Program of Pharmaceutical Sciences, Faculty of Pharmacy, Universitas Airlangga, Campus C UNAIR Mulyorejo, Surabaya 60115, Indonesia
| | - Tamasa Araki
- Department of Parasitology, National Institute of Infectious Diseases (NIID), 1-23-1 Toyama, Shinju-ku, Tokyo 162-8640, Japan
| | - Takeshi Annoura
- Department of Parasitology, National Institute of Infectious Diseases (NIID), 1-23-1 Toyama, Shinju-ku, Tokyo 162-8640, Japan
| | - Retno Sari
- Department of Pharmaceutical Science, Faculty of Pharmacy, Universitas Airlangga, Campus C UNAIR Mulyorejo, Surabaya 60115, Indonesia
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Salazar YEAR, Louzada J, Puça MCSDB, Guimarães LFF, Vieira JLF, de Siqueira AM, Gil JP, de Brito CFA, de Sousa TN. Delayed gametocyte clearance in Plasmodium vivax malaria is associated with polymorphisms in the cytochrome P450 reductase (CPR). Antimicrob Agents Chemother 2024; 68:e0120423. [PMID: 38411047 PMCID: PMC10989009 DOI: 10.1128/aac.01204-23] [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: 09/19/2023] [Accepted: 01/31/2024] [Indexed: 02/28/2024] Open
Abstract
Primaquine (PQ) is the main drug used to eliminate dormant liver stages and prevent relapses in Plasmodium vivax malaria. It also has an effect on the gametocytes of Plasmodium falciparum; however, it is unclear to what extent PQ affects P. vivax gametocytes. PQ metabolism involves multiple enzymes, including the highly polymorphic CYP2D6 and the cytochrome P450 reductase (CPR). Since genetic variability can impact drug metabolism, we conducted an evaluation of the effect of CYP2D6 and CPR variants on PQ gametocytocidal activity in 100 subjects with P. vivax malaria. To determine gametocyte density, we measured the levels of pvs25 transcripts in samples taken before treatment (D0) and 72 hours after treatment (D3). Generalized estimating equations (GEEs) were used to examine the effects of enzyme variants on gametocyte densities, adjusting for potential confounding factors. Linear regression models were adjusted to explore the predictors of PQ blood levels measured on D3. Individuals with the CPR mutation showed a smaller decrease in gametocyte transcript levels on D3 compared to those without the mutation (P = 0.02, by GEE). Consistent with this, higher PQ blood levels on D3 were associated with a lower reduction in pvs25 transcripts. Based on our findings, the CPR variant plays a role in the persistence of gametocyte density in P. vivax malaria. Conceptually, our work points to pharmacogenetics as a non-negligible factor to define potential host reservoirs with the propensity to contribute to transmission in the first days of CQ-PQ treatment, particularly in settings and seasons of high Anopheles human-biting rates.
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Affiliation(s)
- Yanka Evellyn Alves Rodrigues Salazar
- Molecular Biology and Malaria Immunology Research Group, Instituto René Rachou, Fundação Oswaldo Cruz (FIOCRUZ), Belo Horizonte, Minas Gerais, Brazil
| | - Jaime Louzada
- Universidade Federal de Roraima, Boa Vista, Roraima, Brazil
| | - Maria Carolina Silva de Barros Puça
- Molecular Biology and Malaria Immunology Research Group, Instituto René Rachou, Fundação Oswaldo Cruz (FIOCRUZ), Belo Horizonte, Minas Gerais, Brazil
| | - Luiz Felipe Ferreira Guimarães
- Molecular Biology and Malaria Immunology Research Group, Instituto René Rachou, Fundação Oswaldo Cruz (FIOCRUZ), Belo Horizonte, Minas Gerais, Brazil
| | | | - André Machado de Siqueira
- Instituto Nacional de Infectologia Evandro Chagas, Fundação Oswaldo Cruz (FIOCRUZ), Rio de Janeiro, Rio de Janeiro, Brazil
| | - José Pedro Gil
- Department of Microbiology, Tumor and Cell biology, Karolinska Institutet, Solna, Sweden
| | - Cristiana Ferreira Alves de Brito
- Molecular Biology and Malaria Immunology Research Group, Instituto René Rachou, Fundação Oswaldo Cruz (FIOCRUZ), Belo Horizonte, Minas Gerais, Brazil
| | - Tais Nobrega de Sousa
- Molecular Biology and Malaria Immunology Research Group, Instituto René Rachou, Fundação Oswaldo Cruz (FIOCRUZ), Belo Horizonte, Minas Gerais, Brazil
- Department of Microbiology, Tumor and Cell biology, Karolinska Institutet, Solna, Sweden
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Akafity G, Kumi N, Ashong J. Diagnosis and management of malaria in the intensive care unit. JOURNAL OF INTENSIVE MEDICINE 2024; 4:3-15. [PMID: 38263976 PMCID: PMC10800773 DOI: 10.1016/j.jointm.2023.09.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/22/2023] [Revised: 08/17/2023] [Accepted: 09/02/2023] [Indexed: 01/25/2024]
Abstract
Malaria is responsible for approximately three-quarters of a million deaths in humans globally each year. Most of the morbidity and mortality reported are from Sub-Saharan Africa and Asia, where the disease is endemic. In non-endemic areas, malaria is the most common cause of imported infection and is associated with significant mortality despite recent advancements and investments in elimination programs. Severe malaria often requires intensive care unit admission and can be complicated by cerebral malaria, respiratory distress, acute kidney injury, bleeding complications, and co-infection. Intensive care management includes prompt diagnosis and early initiation of effective antimalarial therapy, recognition of complications, and appropriate supportive care. However, the lack of diagnostic capacities due to limited advances in equipment, personnel, and infrastructure presents a challenge to the effective diagnosis and management of malaria. This article reviews the clinical classification, diagnosis, and management of malaria as relevant to critical care clinicians, highlighting the role of diagnostic capacity, treatment options, and supportive care.
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Affiliation(s)
- George Akafity
- Department of Research, Monitoring, and Evaluation, Cape Coast Teaching Hospital, Cape Coast, Ghana
| | - Nicholas Kumi
- Intensive Care Unit, Department of Critical Care and Anesthesia, Cape Coast Teaching Hospital, Cape Coast, Ghana
| | - Joyce Ashong
- Department of Paediatrics and Child Health, Cape Coast Teaching Hospital, Cape Coast, Ghana
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Watson JA, Peto TJ, White NJ. Rectal artesunate suppositories for the pre-referral treatment of suspected severe malaria. PLoS Med 2023; 20:e1004312. [PMID: 37943884 PMCID: PMC10681301 DOI: 10.1371/journal.pmed.1004312] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Revised: 11/27/2023] [Indexed: 11/12/2023] Open
Abstract
In this Policy Forum article, James A. Watson and colleagues discuss recent guidelines relating to pre-referral treatment of suspected severe malaria with rectal artesunate suppositories in remote areas.
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Affiliation(s)
- James A. Watson
- Oxford University Clinical Research Unit, Hospital for Tropical Diseases, Ho Chi Minh City, Vietnam
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, New Richards Building, Old Road Campus, Roosevelt Drive, Oxford, United Kingdom
| | - Thomas J. Peto
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, New Richards Building, Old Road Campus, Roosevelt Drive, Oxford, United Kingdom
- Mahidol Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Nicholas J. White
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, New Richards Building, Old Road Campus, Roosevelt Drive, Oxford, United Kingdom
- Mahidol Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
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Mbassi DE, Pfaffendorf C, Mombo-Ngoma G, Kreuels B, Ramharter M. Real-life effectiveness of anti-malarial treatment regimens: what are we aiming for? Malar J 2023; 22:189. [PMID: 37340324 DOI: 10.1186/s12936-023-04606-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2023] [Accepted: 05/25/2023] [Indexed: 06/22/2023] Open
Abstract
Three-day artemisinin-based combination therapy (ACT) is the current standard of care for the treatment of malaria. However, specific drug resistance associated with reduced efficacy of ACT has been observed, therefore necessitating the clinical development of new anti-malarial drugs and drug combinations. Previously, Single Encounter Radical Cure and Prophylaxis (SERCAP) has been proposed as ideal target-product-profile for any new anti-malarial drug regimen as this would improve treatment adherence besides ensuring complete cure and prevention of early reinfection. Arguably, this concept may not be ideal as it (1) necessitates administration of an excessively high dose of drug to achieve plasmodicidal plasma levels for a sufficient time span, (2) increases the risk for drug related adverse drug reactions, and (3) leaves the patient with a one-time opportunity to achieve-or not-cure by a single drug intake. Over the past years, SERCAP has led to the halt of promising drug development programmes, leading to potentially unnecessary attrition in the anti-malarial development pipeline. One proposition could be the concept of single-day multi-dose regimens as a potentially better alternative, as this allows to (1) administer a lower dose of the drug at each time-point leading to better tolerability and safety, (2) increase treatment adherence based on the intake of the anti-malarial drug within 24 h when malaria-related symptoms are still present, and (3) have more than one opportunity for adequate intake of the drug in case of early vomiting or other factors causing reduced bioavailability. In line with a recently published critical viewpoint on the concept of SERCAP, an alternative proposition is-in contrast to the current World Health Organization (WHO) treatment guidelines-to aim for less than three days, but still multiple-dose anti-malarial treatment regimens. This may help to strike the optimal balance between improving treatment adherence, maximizing treatment effectiveness, while keeping attrition of new drugs and drug regimens as low as possible.
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Affiliation(s)
- Dorothea Ekoka Mbassi
- Department of Tropical Medicine, Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany
- Department of Medicine, University Medical Centre Hamburg-Eppendorf, Hamburg, Germany
- German Centre for Infection Research (DZIF), Partner Site Hamburg-Lübeck-Borstel, Hamburg, Germany
- Centre de Recherches Médicales de Lambaréné, Lambaréné, Gabon
| | - Christoph Pfaffendorf
- Department of Clinical Pharmacy, Institute of Pharmacy, University of Hamburg, 20146, Hamburg, Germany
| | - Ghyslain Mombo-Ngoma
- Department of Medicine, University Medical Centre Hamburg-Eppendorf, Hamburg, Germany
- Department of Implementation Research, Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany
- Centre de Recherches Médicales de Lambaréné, Lambaréné, Gabon
| | - Benno Kreuels
- Department of Medicine, University Medical Centre Hamburg-Eppendorf, Hamburg, Germany
- Department of Implementation Research, Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany
| | - Michael Ramharter
- Department of Tropical Medicine, Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany.
- Department of Medicine, University Medical Centre Hamburg-Eppendorf, Hamburg, Germany.
- German Centre for Infection Research (DZIF), Partner Site Hamburg-Lübeck-Borstel, Hamburg, Germany.
- Centre de Recherches Médicales de Lambaréné, Lambaréné, Gabon.
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Saeheng T, Na-Bangchang K. Prediction of improved antimalarial chemotherapy of artesunate-mefloquine in combination with mefloquine sensitive and resistant Plasmodium falciparum malaria. PLoS One 2023; 18:e0282099. [PMID: 36821622 PMCID: PMC9949628 DOI: 10.1371/journal.pone.0282099] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2022] [Accepted: 02/07/2023] [Indexed: 02/24/2023] Open
Abstract
BACKGROUND Declining in susceptibility of Plasmodium falciparum to mefloquine is reported in South-East Asia. A revisiting on mefloquine pharmacokinetics-pharmacodynamics (PK/PD) could assist in finding new appropriate dosage regimens in combination with artesunate as a three-day course treatment. OBJECTIVE This study aimed to investigate promising alternative artesunate-mefloquine combination regimens that are effective for the treatment of patients with mefloquine-sensitive and resistant P. falciparum malaria. METHODS Data collected during 2008-2009 from 124 patients with uncomplicated P. falciparum malaria were included in the analysis, 90 and 34 patients with sensitive and recrudescence response, respectively. All patients were treated with a three-day combination of artesunate-mefloquine. Population PK-PD models were developed. The developed models were validated with clinically observed data. Simulations of clinical efficacy of alternative mefloquine regimens were performed based on mefloquine sensitivity, patients' adherence and parasite biomass. RESULTS The developed PK/PD models well described with clinically observed data. For mefloquine-resistant P. falciparum, a three-day standard regimen of artesunate-mefloquine is suitable (>50% efficacy) only when the level of parasite sensitivity was < 1.5-fold of the cut-off level (IC50 < 36 nM). For mefloquine-sensitive parasite with IC50 < 23.19 nM (0.96-fold), all regimens provided satisfactory efficacy. In the isolates with IC50 of 24 nM, regimen-I is recommended. Curative treatment criteria for mefloquine and artesunate were C336h (>408 ng.mL-1) or Cmax/IC50 (>130.1 g.m/M), and Cmax/IC50 (>381.2 g.m/M), respectively. CONCLUSIONS Clinical use of a three-day standard artesunate-mefloquine is suitable only when the IC50 of P. falciparum isolates is lower than 36 nM. Otherwise, other ACT regimens should be replaced. For mefloquine-sensitive parasite, a dose reduction is recommended with the IC50 is lower than 23.19 nM.
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Affiliation(s)
- Teerachat Saeheng
- Center of Excellence in Pharmacology and Molecular Biology of Malaria and Cholangiocarcinoma, Chulabhorn International College, Thammasat University (Rangsit Campus), Klongneung, Klongluang District, Pathumthani, Thailand
| | - Kesara Na-Bangchang
- Center of Excellence in Pharmacology and Molecular Biology of Malaria and Cholangiocarcinoma, Chulabhorn International College, Thammasat University (Rangsit Campus), Klongneung, Klongluang District, Pathumthani, Thailand
- Drug Discovery and Development Center, Office of Advanced Science and Technology, Thammasat University (Rangsit Campus), Klongneung, Klongluang District, Pathumthani, Thailand
- * E-mail:
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Banda CG, Nkosi D, Allen E, Workman L, Madanitsa M, Chirwa M, Kapulula M, Muyaya S, Munharo S, Tarning J, Phiri KS, Mwapasa V, ter Kuile FO, Maartens G, Barnes KI. Impact of Dolutegravir-Based Antiretroviral Therapy on Piperaquine Exposure following Dihydroartemisinin-Piperaquine Intermittent Preventive Treatment of Malaria in Pregnant Women Living with HIV. Antimicrob Agents Chemother 2022; 66:e0058422. [PMID: 36374096 PMCID: PMC9764988 DOI: 10.1128/aac.00584-22] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Dihydroartemisinin-piperaquine, an artemisinin-based combination therapy, has been identified as a promising agent for intermittent preventive treatment of malaria in pregnancy. However, in pregnant women living with HIV (PLWH), efavirenz-based antiretroviral therapy (ART) significantly reduces the plasma exposure of piperaquine. In an open-label, nonrandomized, fixed-sequence, pharmacokinetic study, we compared piperaquine plasma concentrations in 13 pregnant women during a 3-day treatment course of dihydroartemisinin-piperaquine when coadministered with efavirenz-based versus dolutegravir-based ART in the second or third trimester of pregnancy. Piperaquine concentrations were measured over a 28-day period, while on efavirenz-based ART and after switching to dolutegravir-based ART. Noncompartmental analysis was performed, and geometric mean ratios (GMRs) and 90% confidence intervals (CIs) were generated to compare piperaquine pharmacokinetic parameters between these two treatment periods. Compared with efavirenz-based ART, coadministration of dihydroartemisinin-piperaquine and dolutegravir-based ART resulted in a 57% higher overall piperaquine exposure (area under the concentration-time curve from 0 to 672 h [AUC0-672 h]) (GMR, 1.57; 90% CI, 1.28 to 1.93). Piperaquine's day 7 concentrations were also 63% higher (GMR, 1.63; 90% CI, 1.29 to 2.11), while day 28 concentrations were nearly three times higher (GMR, 2.96; 90% CI, 2.25 to 4.07). However, the maximum piperaquine concentration (Cmax) remained similar (GMR, 1.09; 90% CI, 0.79 to 1.49). Dihydroartemisinin-piperaquine was well tolerated, with no medication-related serious adverse events observed in this small study. Compared with efavirenz-based ART, a known inducer of piperaquine metabolism, dolutegravir-based ART resulted in increased overall piperaquine exposure with pharmacokinetic parameter values that were similar to those published previously for pregnant and nonpregnant women. Our findings suggest that the efficacy of dihydroartemisinin-piperaquine will be retained in pregnant women on dolutegravir. (The study was registered on PACTR.samrc.ac.za [PACTR201910580840196].).
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Affiliation(s)
- Clifford G. Banda
- Malawi-Liverpool-Wellcome Research Programme, Blantyre, Malawi
- Division of Clinical Pharmacology, Department of Medicine, University of Cape Towngrid.7836.a, Cape Town, South Africa
- Kamuzu University of Health Sciences (formerly College of Medicine and Kamuzu College of Nursing, University of Malawi), Blantyre, Malawi
| | - Dumisile Nkosi
- Malawi-Liverpool-Wellcome Research Programme, Blantyre, Malawi
| | - Elizabeth Allen
- Division of Clinical Pharmacology, Department of Medicine, University of Cape Towngrid.7836.a, Cape Town, South Africa
- WorldWide Antimalarial Resistance Network (WWARN), Pharmacology Scientific Group, University of Cape Towngrid.7836.a, Cape Town, South Africa
| | - Lesley Workman
- Division of Clinical Pharmacology, Department of Medicine, University of Cape Towngrid.7836.a, Cape Town, South Africa
- WorldWide Antimalarial Resistance Network (WWARN), Pharmacology Scientific Group, University of Cape Towngrid.7836.a, Cape Town, South Africa
| | - Mwayiwawo Madanitsa
- Training and Research Unit of Excellence, Blantyre, Malawi
- Department of Clinical Sciences, Malawi University of Science and Technology, Limbe, Malawi
| | - Marumbo Chirwa
- Malawi-Liverpool-Wellcome Research Programme, Blantyre, Malawi
| | | | - Sharon Muyaya
- Training and Research Unit of Excellence, Blantyre, Malawi
| | - Steven Munharo
- Training and Research Unit of Excellence, Blantyre, Malawi
| | - Joel Tarning
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Kamija S. Phiri
- Kamuzu University of Health Sciences (formerly College of Medicine and Kamuzu College of Nursing, University of Malawi), Blantyre, Malawi
- Training and Research Unit of Excellence, Blantyre, Malawi
| | - Victor Mwapasa
- Kamuzu University of Health Sciences (formerly College of Medicine and Kamuzu College of Nursing, University of Malawi), Blantyre, Malawi
- Training and Research Unit of Excellence, Blantyre, Malawi
| | - Feiko O. ter Kuile
- Department of Clinical Sciences, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
| | - Gary Maartens
- Division of Clinical Pharmacology, Department of Medicine, University of Cape Towngrid.7836.a, Cape Town, South Africa
| | - Karen I. Barnes
- Division of Clinical Pharmacology, Department of Medicine, University of Cape Towngrid.7836.a, Cape Town, South Africa
- WorldWide Antimalarial Resistance Network (WWARN), Pharmacology Scientific Group, University of Cape Towngrid.7836.a, Cape Town, South Africa
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Trinh TTT, Yun SY, Bae GJ, Moon K, Hong H, Eum TH, Kim YA, Kim SA, Park H, Kim HS, Yeo SJ. Anti-malarial activity of HCl salt of SKM13 (SKM13-2HCl). Int J Parasitol Drugs Drug Resist 2022; 20:113-120. [PMID: 36375338 PMCID: PMC9771833 DOI: 10.1016/j.ijpddr.2022.10.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2022] [Revised: 10/24/2022] [Accepted: 10/25/2022] [Indexed: 11/11/2022]
Abstract
Malaria is among the most devastating and widespread tropical parasitic diseases in developing countries. To prevent a potential public health emergency, there is an urgent need for new antimalarial drugs, with single-dose cures, broad therapeutic potential, and novel mechanism of action. We synthesized HCl salt of SKM13 (SKM13-2HCl) based on the modification of SKM13 to improve solubility in water. The anti-malarial activity of the synthesized drug was evaluated in both in vitro and in vivo models. The selective index indicated that SKM13-2HCl showed the same effectiveness with SKM13 in Plasmodium falciparum in in-vitro. Even though, in vivo mouse study demonstrated that SKM13 (20 mg/kg) at single dose could not completely inhibit P. berghei growth in blood. The survival rate increased from 33 to 90% at 15 days after infection. However, SKM13-2HCl (20 mg/kg) at a single dose increased the survival rate up to 100% at the same duration. Ultra-High-Performance Liquid Chromatography (UHPLC) showed that solubility in water of SKM13 and SKM13-2HCL was 0.389 mg/mL and 417 mg/mL, respectively. Pharmacokinetics (PK) analysis corresponded to the increased solubility of SKM13-2HCl over SKM13. Haematological parameters [red blood cell (RBC) count, haemoglobin level, and haematocrit level] supported the comparable efficacy of SKM13 and SKM13-2HCl in a 4-day suppression test. One mode of these drugs was found to be activating phosphorylation of eIF2α, hallmark of ER-stress, to kill parasite. Novel salt derivative of SKM13 (SKM13-2HCl) have enhanced anti-malarial activity against P. falciparum with endoplasmic reticulum (ER)-stress and salt form of SKM13 is an excellent direction to develop anti-malarial drug candidate in mice model.
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Affiliation(s)
- Thuy-Tien Thi Trinh
- Department of Tropical Medicine and Parasitology, Medical Research Center, Institute of Endemic Diseases, Seoul National University, Seoul, 03080, Republic of Korea
| | - Su-Yeon Yun
- Zoonosis Research Center, Department of Infection Biology, School of Medicine, Wonkwang University, 460 Iksan-daero, Iksan, 54538, Republic of Korea
| | - Gum-Ju Bae
- Zoonosis Research Center, Department of Infection Biology, School of Medicine, Wonkwang University, 460 Iksan-daero, Iksan, 54538, Republic of Korea
| | - Kwonmo Moon
- College of Pharmacy, Institute of Pharmaceutical Research and Development, Wonkwang University, 460, Iksan-daero, Iksan, 54538, Republic of Korea
| | - Hyelee Hong
- Department of Tropical Medicine and Parasitology, Department of Biomedical Sciences, College of Medicine, Seoul National University, Seoul, 03080, Republic of Korea
| | - Tae Hui Eum
- Department of Tropical Medicine and Parasitology, Department of Biomedical Sciences, College of Medicine, Seoul National University, Seoul, 03080, Republic of Korea
| | - Young-Ah Kim
- College of Pharmacy, Institute of Pharmaceutical Research and Development, Wonkwang University, 460, Iksan-daero, Iksan, 54538, Republic of Korea
| | - Soon-Ai Kim
- College of Pharmacy, Institute of Pharmaceutical Research and Development, Wonkwang University, 460, Iksan-daero, Iksan, 54538, Republic of Korea
| | - Hyun Park
- Zoonosis Research Center, Department of Infection Biology, School of Medicine, Wonkwang University, 460 Iksan-daero, Iksan, 54538, Republic of Korea.
| | - Hak Sung Kim
- College of Pharmacy, Institute of Pharmaceutical Research and Development, Wonkwang University, 460, Iksan-daero, Iksan, 54538, Republic of Korea.
| | - Seon-Ju Yeo
- Department of Tropical Medicine and Parasitology, Medical Research Center, Institute of Endemic Diseases, Seoul National University, Seoul, 03080, Republic of Korea; Department of Tropical Medicine and Parasitology, Department of Biomedical Sciences, College of Medicine, Seoul National University, Seoul, 03080, Republic of Korea.
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10
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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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11
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White NJ. The assessment of antimalarial drug efficacy in vivo. Trends Parasitol 2022; 38:660-672. [PMID: 35680541 PMCID: PMC7613059 DOI: 10.1016/j.pt.2022.05.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2022] [Revised: 05/13/2022] [Accepted: 05/16/2022] [Indexed: 11/19/2022]
Abstract
Currently recommended methods of assessing the efficacy of uncomplicated falciparum malaria treatment work less well in high-transmission than in low-transmission settings. There is also uncertainty how to assess intermittent preventive therapies and seasonal malaria chemoprevention (SMC), and Plasmodium vivax radical cure. A pharmacometric antimalarial resistance monitoring (PARM) approach is proposed specifically for evaluating slowly eliminated antimalarial drugs in areas of high transmission. In PARM antimalarial drug concentrations at recurrent parasitaemia are measured to identify outliers (i.e., recurrent parasitaemias in the presence of normally suppressive drug concentrations) and to evaluate changes over time. PARM requires characterization of pharmacometric profiles but should be simpler and more sensitive than current molecular genotyping-based methodologies. PARM does not require parasite genotyping and can be applied to the assessment of both prevention and treatment.
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Affiliation(s)
- 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, Oxford University, Oxford, UK.
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12
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de Vries LE, Jansen PAM, Barcelo C, Munro J, Verhoef JMJ, Pasaje CFA, Rubiano K, Striepen J, Abla N, Berning L, Bolscher JM, Demarta-Gatsi C, Henderson RWM, Huijs T, Koolen KMJ, Tumwebaze PK, Yeo T, Aguiar ACC, Angulo-Barturen I, Churchyard A, Baum J, Fernández BC, Fuchs A, Gamo FJ, Guido RVC, Jiménez-Diaz MB, Pereira DB, Rochford R, Roesch C, Sanz LM, Trevitt G, Witkowski B, Wittlin S, Cooper RA, Rosenthal PJ, Sauerwein RW, Schalkwijk J, Hermkens PHH, Bonnert RV, Campo B, Fidock DA, Llinás M, Niles JC, Kooij TWA, Dechering KJ. Preclinical characterization and target validation of the antimalarial pantothenamide MMV693183. Nat Commun 2022; 13:2158. [PMID: 35444200 PMCID: PMC9021288 DOI: 10.1038/s41467-022-29688-5] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2021] [Accepted: 03/09/2022] [Indexed: 12/14/2022] Open
Abstract
Drug resistance and a dire lack of transmission-blocking antimalarials hamper malaria elimination. Here, we present the pantothenamide MMV693183 as a first-in-class acetyl-CoA synthetase (AcAS) inhibitor to enter preclinical development. Our studies demonstrate attractive drug-like properties and in vivo efficacy in a humanized mouse model of Plasmodium falciparum infection. The compound shows single digit nanomolar in vitro activity against P. falciparum and P. vivax clinical isolates, and potently blocks P. falciparum transmission to Anopheles mosquitoes. Genetic and biochemical studies identify AcAS as the target of the MMV693183-derived antimetabolite, CoA-MMV693183. Pharmacokinetic-pharmacodynamic modelling predict that a single 30 mg oral dose is sufficient to cure a malaria infection in humans. Toxicology studies in rats indicate a > 30-fold safety margin in relation to the predicted human efficacious exposure. In conclusion, MMV693183 represents a promising candidate for further (pre)clinical development with a novel mode of action for treatment of malaria and blocking transmission. Here, de Vries et al. perform a pre-clinical characterization of the antimalarial compound MMV693183: the compound targets acetyl-CoA synthetase, has efficacy in humanized mice against Plasmodium falciparum infection, blocks transmission to mosquito vectors, is safe in rats, and pharmacokinetic-pharmacodynamic modeling informs about a potential oral human dosing regimen.
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Affiliation(s)
- Laura E de Vries
- Department of Medical Microbiology, Radboudumc Center for Infectious Diseases, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, The Netherlands.,Department of Immunology and Infectious Diseases, Harvard T.H. Chan School of Public Health, Boston, MA, USA
| | - Patrick A M Jansen
- Department of Dermatology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, The Netherlands
| | | | - Justin Munro
- Department of Chemistry and Huck Center for Malaria Research, The Pennsylvania State University, University Park, PA, USA
| | - Julie M J Verhoef
- Department of Medical Microbiology, Radboudumc Center for Infectious Diseases, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, The Netherlands
| | | | - Kelly Rubiano
- Department of Microbiology & Immunology, Columbia University Irving Medical Center, New York, NY, USA
| | - Josefine Striepen
- Department of Microbiology & Immunology, Columbia University Irving Medical Center, New York, NY, USA
| | - Nada Abla
- Medicines for Malaria Venture, Geneva, Switzerland
| | - Luuk Berning
- TropIQ Health Sciences, Nijmegen, The Netherlands
| | | | | | | | - Tonnie Huijs
- TropIQ Health Sciences, Nijmegen, The Netherlands
| | | | | | - Tomas Yeo
- Department of Microbiology & Immunology, Columbia University Irving Medical Center, New York, NY, USA
| | - Anna C C Aguiar
- Sao Carlos Institute of Physics, University of São Paulo, São Carlos, São Paulo, Brazil, São Carlos, SP, Brazil
| | | | - Alisje Churchyard
- Department of Life Sciences, Imperial College London, South Kensington, London, United Kingdom
| | - Jake Baum
- Department of Life Sciences, Imperial College London, South Kensington, London, United Kingdom
| | | | - Aline Fuchs
- Medicines for Malaria Venture, Geneva, Switzerland
| | | | - Rafael V C Guido
- Sao Carlos Institute of Physics, University of São Paulo, São Carlos, São Paulo, Brazil, São Carlos, SP, Brazil
| | | | - Dhelio B Pereira
- Research Center for Tropical Medicine of Rondonia, Porto Velho, Brazil
| | - Rosemary Rochford
- Department of Immunology and Microbiology, University of Colorado Anschutz School of Medicine, Aurora, CO, USA
| | - Camille Roesch
- Malaria Molecular Epidemiology Unit, Institut Pasteur du Cambodge, Phnom Penh, Cambodia.,Malaria Translational Research Unit, Institut Pasteur, Paris & Institut Pasteur du Cambodge, Phnom Penh, Cambodia
| | - Laura M Sanz
- Global Health, GlaxoSmithKline, Tres Cantos, Madrid, Spain
| | | | - Benoit Witkowski
- Malaria Molecular Epidemiology Unit, Institut Pasteur du Cambodge, Phnom Penh, Cambodia.,Malaria Translational Research Unit, Institut Pasteur, Paris & Institut Pasteur du Cambodge, Phnom Penh, Cambodia
| | - Sergio Wittlin
- Swiss Tropical and Public Health Institute, Basel, Switzerland.,University of Basel, Basel, Switzerland
| | - Roland A Cooper
- Department of Natural Sciences and Mathematics, Dominican University of California, San Rafael, CA, USA
| | - Philip J Rosenthal
- Department of Medicine, University of California, San Francisco, CA, USA
| | - Robert W Sauerwein
- Department of Medical Microbiology, Radboudumc Center for Infectious Diseases, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, The Netherlands.,TropIQ Health Sciences, Nijmegen, The Netherlands
| | - Joost Schalkwijk
- Department of Dermatology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, The Netherlands
| | | | | | - Brice Campo
- Medicines for Malaria Venture, Geneva, Switzerland
| | - David A Fidock
- Department of Microbiology & Immunology, Columbia University Irving Medical Center, New York, NY, USA.,Center for Malaria Therapeutics and Antimicrobial Resistance, Division of Infectious Diseases, Department of Medicine, Columbia University Irving Medical Center, New York, NY, USA
| | - Manuel Llinás
- Department of Chemistry and Huck Center for Malaria Research, The Pennsylvania State University, University Park, PA, USA.,Department of Biochemistry & Molecular Biology, The Pennsylvania State University, University Park, PA, USA
| | - Jacquin C Niles
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Taco W A Kooij
- Department of Medical Microbiology, Radboudumc Center for Infectious Diseases, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, The Netherlands.
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13
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Yang J, Wang Y, Guan W, Su W, Li G, Zhang S, Yao H. Spiral molecules with antimalarial activities: A review. Eur J Med Chem 2022; 237:114361. [DOI: 10.1016/j.ejmech.2022.114361] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2022] [Revised: 04/03/2022] [Accepted: 04/04/2022] [Indexed: 11/04/2022]
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14
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An innovative study design with intermittent dosing to generate a GLP-regulatory package in preclinical species for long lasting molecule M5717, inhibitor of Plasmodium eukaryotic translation elongation factor 2. Toxicol Appl Pharmacol 2022; 443:116006. [DOI: 10.1016/j.taap.2022.116006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2021] [Revised: 03/24/2022] [Accepted: 03/27/2022] [Indexed: 11/18/2022]
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15
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Clinical pharmacokinetics of quinine and its relationship with treatment outcomes in children, pregnant women, and elderly patients, with uncomplicated and complicated malaria: a systematic review. Malar J 2022; 21:41. [PMID: 35144612 PMCID: PMC8832728 DOI: 10.1186/s12936-022-04065-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2021] [Accepted: 01/30/2022] [Indexed: 11/22/2022] Open
Abstract
Background Standard dosage regimens of quinine formulated for adult patients with uncomplicated and complicated malaria have been applied for clinical uses in children, pregnant women, and elderly. Since these populations have anatomical and physiological differences from adults, dosage regimens formulated for adults may not be appropriate. The study aimed to (i) review existing information on the pharmacokinetics of quinine in children, pregnant women, and elderly populations, (ii) identify factors that influence quinine pharmacokinetics, and (iii) analyse the relationship between the pharmacokinetics and treatment outcomes (therapeutic and safety) of various dosage regimens of quinine. Methods Web of Sciences, Cochrane Library, Scopus, and PubMed were the databases applied in this systematic search for relevant research articles published up to October 2020 using the predefined search terms. The retrieved articles were initially screened by titles and abstracts to exclude any irrelevant articles and were further evaluated based on full-texts, applying the predefined eligibility criteria. Excel spreadsheet (Microsoft, WA, USA) was used for data collection and management. Qualitative data are presented as numbers and percentages, and where appropriate, mean + SD or median (range) or range values. Results Twenty-eight articles fulfilled the eligibility criteria, 19 in children, 7 in pregnant women, and 2 in elderly (14 and 7 articles in complicated and uncomplicated malaria, respectively). Severity of infection, routes of administration, and nutritional status were shown to be the key factors impacting quinine pharmacokinetics in these vulnerable groups. Conclusions The recommended dosages for both uncomplicated and complicated malaria are, in general, adequate for elderly and children with uncomplicated malaria. Dose adjustment may be required in pregnant women with both uncomplicated and complicated malaria, and in children with complicated malaria. Pharmacokinetics studies relevant to clinical efficacy in these vulnerable groups of patients with large sample size and reassessment of MIC (minimum inhibitory concentration) should be considered. Supplementary Information The online version contains supplementary material available at 10.1186/s12936-022-04065-1.
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16
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Zeng S, Wang H, Tao L, Ning X, Fan Y, Zhao S, Qin L, Chen X. Decoquinate liposomes: highly effective clearance of Plasmodium parasites causing severe malaria. Malar J 2022; 21:24. [PMID: 35073922 PMCID: PMC8785525 DOI: 10.1186/s12936-022-04042-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2021] [Accepted: 01/07/2022] [Indexed: 11/19/2022] Open
Abstract
Background Severe malaria caused by Plasmodium falciparum leads to most malaria-related deaths globally. Decoquinate (DQ) displays strong activity against multistage infection by Plasmodium parasites. However, the development of DQ as an oral dosage form for the treatment of malaria at the blood stage has not been successful. In this study, liposome formulations of DQ were created for intravenous (IV) injection to suppress Plasmodium berghei, a parasite that causes severe malaria in mice. Methods DQ liposomes were prepared by conventional ethanol injection method with slight modifications and encapsulation efficiency evaluated by the well-established centrifugation method. Potency of the DQ liposomes against P. falciparum was assessed in vitro using freshly isolated human red blood cells. The efficacy of the DQ liposomes was examined in the mouse model of severe malaria. Results The DQ liposomes were around 150 nm in size and had the encapsulation efficiency rates > 95%. The freshly prepared and lyophilized liposomes were stable after storage at − 20 °C for 6 months. The liposomes were shown to have excellent activity against P. falciparum in vitro with DQ IC50 0.91 ± 0.05 nM for 3D7 (chloroquine sensitive strain) and DQ IC50 1.33 ± 0.14 nM for Dd2 (multidrug resistant strain), which were 18- and 14-fold more potent than artemisinin, respectively. Mice did not have any signs of toxicity after receiving high dose of the liposomes (DQ 500 mg/kg per mouse) by IV injection. In the mouse model of severe malaria, the liposomes had impressive efficacy against P. berghei with DQ ED50 of 0.720 mg/kg. Conclusion The DQ liposomes prepared in this study were stable for long term storage and safe for IV injection in mammalian animals. The newly created liposome formulations had excellent activity against Plasmodium infection at the blood-stage, which encourages their application in the treatment of severe malaria.
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Affiliation(s)
- Sumei Zeng
- Guangzhou Bluelight Pharmaceutical Technology Co., Ltd, International Business Incubator, Guangzhou Science Park, Guangzhou, 510663, China
| | - Hongxing Wang
- Guangzhou Bluelight Pharmaceutical Technology Co., Ltd, International Business Incubator, Guangzhou Science Park, Guangzhou, 510663, China. .,CAS Lamvac Biotech Co. Ltd, International Business Incubator, Guangzhou Science Park, Guangzhou, 510663, China.
| | - Long Tao
- Guangzhou Bluelight Pharmaceutical Technology Co., Ltd, International Business Incubator, Guangzhou Science Park, Guangzhou, 510663, China
| | - Xiaohui Ning
- Guangzhou Bluelight Pharmaceutical Technology Co., Ltd, International Business Incubator, Guangzhou Science Park, Guangzhou, 510663, China
| | - Yinzhou Fan
- Guangzhou Bluelight Pharmaceutical Technology Co., Ltd, International Business Incubator, Guangzhou Science Park, Guangzhou, 510663, China
| | - Siting Zhao
- CAS Lamvac Biotech Co. Ltd, International Business Incubator, Guangzhou Science Park, Guangzhou, 510663, China
| | - Li Qin
- CAS Lamvac Biotech Co. Ltd, International Business Incubator, Guangzhou Science Park, Guangzhou, 510663, China
| | - Xiaoping Chen
- CAS Lamvac Biotech Co. Ltd, International Business Incubator, Guangzhou Science Park, Guangzhou, 510663, China
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17
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Chung IY, Jang HJ, Yoo YJ, Hur J, Oh HY, Kim SH, Cho YH. Artemisinin displays bactericidal activity via copper-mediated DNA damage. Virulence 2022; 13:149-159. [PMID: 34983312 PMCID: PMC8741286 DOI: 10.1080/21505594.2021.2021643] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Artemisinin (ARS) and its semi-synthetic derivatives are effective drugs to treat malaria and possess multiple therapeutic activities based on their endoperoxide bridge. Here, we showed that ARS displayed antibacterial efficacy in Drosophila systemic infections caused by bacterial pathogens but killed only Vibrio cholerae (VC) in vitro, involving reactive oxygen species (ROS) generation and/or DNA damage. This selective antibacterial activity of ARS was attributed to the higher intracellular copper levels in VC, in that the antibacterial activity was observed in vitro upon addition of cuprous ions even against other bacteria and was compromised by the copper-specific chelators neocuproine (NC) and triethylenetetramine (TETA) in vitro and in vivo. We suggest that copper can enhance or reinforce the therapeutic activities of ARS to be repurposed as an antibacterial drug for the treatment of bacterial infections.
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Affiliation(s)
- In-Young Chung
- Department of Pharmacy, College of Pharmacy and Institute of Pharmaceutical Sciences, Cha University, Gyeonggi-do, Korea
| | - Hye-Jeong Jang
- Department of Pharmacy, College of Pharmacy and Institute of Pharmaceutical Sciences, Cha University, Gyeonggi-do, Korea
| | - Yeon-Ji Yoo
- Department of Pharmacy, College of Pharmacy and Institute of Pharmaceutical Sciences, Cha University, Gyeonggi-do, Korea
| | - Joonseong Hur
- Department of Pharmacy, College of Pharmacy and Institute of Pharmaceutical Sciences, Cha University, Gyeonggi-do, Korea
| | - Hyo-Young Oh
- Department of Pharmacy, College of Pharmacy and Institute of Pharmaceutical Sciences, Cha University, Gyeonggi-do, Korea
| | - Seok-Ho Kim
- Department of Pharmacy, College of Pharmacy and Institute of Pharmaceutical Sciences, Cha University, Gyeonggi-do, Korea
| | - You-Hee Cho
- Department of Pharmacy, College of Pharmacy and Institute of Pharmaceutical Sciences, Cha University, Gyeonggi-do, Korea
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18
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Antimalarial drug candidates in phase I and II drug development: a scoping review. Antimicrob Agents Chemother 2021; 66:e0165921. [PMID: 34843390 PMCID: PMC8846400 DOI: 10.1128/aac.01659-21] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The emergence and spread of parasite resistance to currently available antimalarials has highlighted the importance of developing novel antimalarials. This scoping review provides an overview of antimalarial drug candidates undergoing phase I and II studies between 1 January 2016 and 28 April 2021. PubMed, Web of Science, Embase, clinical trial registries, and reference lists were searched for relevant studies. Information regarding antimalarial compound details, clinical trial characteristics, study population, and drug pharmacokinetics and pharmacodynamics (PK-PD) were extracted. A total of 50 studies were included, of which 24 had published their results and 26 were unpublished. New antimalarial compounds were evaluated as monotherapy (28 studies, 14 drug candidates) and combination therapy (9 studies, 10 candidates). Fourteen active compounds were identified in the current antimalarial drug development pipeline together with 11 compounds that are inactive, 6 due to insufficient efficacy. PK-PD data were available from 24 studies published as open-access articles. Four unpublished studies have made their results publicly available on clinical trial registries. The terminal elimination half-life of new antimalarial compounds ranged from 14.7 to 483 h. The log10 parasite reduction ratio over 48 h and parasite clearance half-life for Plasmodium falciparum following a single-dose monotherapy were 1.55 to 4.1 and 3.4 to 9.4 h, respectively. The antimalarial drug development landscape has seen a number of novel compounds, with promising PK-PD properties, evaluated in phase I and II studies over the past 5 years. Timely public disclosure of PK-PD data is crucial for informative decision-making and drug development strategy.
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Absorption and Distribution of Toltrazuril and Toltrazuril Sulfone in Plasma, Intestinal Tissues and Content of Piglets after Oral or Intramuscular Administration. Molecules 2021; 26:molecules26185633. [PMID: 34577103 PMCID: PMC8468611 DOI: 10.3390/molecules26185633] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2021] [Revised: 09/07/2021] [Accepted: 09/14/2021] [Indexed: 11/17/2022] Open
Abstract
Piglet coccidiosis due to Cystoisospora suis is a major cause of diarrhea and poor growth worldwide. It can effectively be controlled by application of toltrazuril (TZ), and oral formulations have been licensed for many years. Recently, the first parenteral formulation containing TZ in combination with iron (gleptoferron) was registered in the EU for the prevention of coccidiosis and iron deficiency anemia, conditions in suckling piglets requiring routine preventive measures. This study evaluated the absorption and distribution of TZ and its main metabolite, toltrazuril sulfone (TZ-SO2), in blood and intestinal tissues after single oral (20 mg/kg) or single intramuscular (45 mg/piglet) application of TZ. Fifty-six piglets were randomly allocated to the two treatment groups. Animals were sacrificed 1-, 5-, 13-, and 24-days post-treatment and TZ and TZ-SO2 levels were determined in blood, jejunal tissue, ileal tissue, and mixed jejunal and ileal content (IC) by high performance liquid chromatography (HPLC). Intramuscular application resulted in significantly higher and more sustained concentrations of both compounds in plasma, intestinal tissue, and IC. Higher concentrations after oral dosing were only observed one day after application of TZ in jejunum and IC. Toltrazuril was quickly metabolized to TZ-SO2 with maximum concentrations on day 13 for both applications. Remarkably, TZ and TZ-SO2 accumulated in the jejunum, the primary predilection site of C. suis, independently of the administration route, which is key to their antiparasitic effect.
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20
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Boberg M, Cal M, Kaiser M, Jansson-Löfmark R, Mäser P, Ashton M. Enantiospecific antitrypanosomal in vitro activity of eflornithine. PLoS Negl Trop Dis 2021; 15:e0009583. [PMID: 34252098 PMCID: PMC8297939 DOI: 10.1371/journal.pntd.0009583] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2021] [Revised: 07/22/2021] [Accepted: 06/21/2021] [Indexed: 11/19/2022] Open
Abstract
The polyamine synthesis inhibitor eflornithine is a recommended treatment for the neglected tropical disease Gambian human African trypanosomiasis in late stage. This parasitic disease, transmitted by the tsetse fly, is lethal unless treated. Eflornithine is administered by repeated intravenous infusions as a racemic mixture of L-eflornithine and D-eflornithine. The study compared the in vitro antitrypanosomal activity of the two enantiomers with the racemic mixture against three Trypanosoma brucei gambiense strains. Antitrypanosomal in vitro activity at varying drug concentrations was analysed by non-linear mixed effects modelling. For all three strains, L-eflornithine was more potent than D-eflornithine. Estimated 50% inhibitory concentrations of the three strains combined were 9.1 μM (95% confidence interval [8.1; 10]), 5.5 μM [4.5; 6.6], and 50 μM [42; 57] for racemic eflornithine, L-eflornithine and D-eflornithine, respectively. The higher in vitro potency of L-eflornithine warrants further studies to assess its potential for improving the treatment of late-stage Gambian human African trypanosomiasis.
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Affiliation(s)
- Mikael Boberg
- Unit for Pharmacokinetics and Drug Metabolism, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - Monica Cal
- Parasite Chemotherapy Unit, Department of Medical Parasitology and Infection Biology, Swiss Tropical and Public Health Institute, Basel, Switzerland
- University of Basel, Basel, Switzerland
| | - Marcel Kaiser
- Parasite Chemotherapy Unit, Department of Medical Parasitology and Infection Biology, Swiss Tropical and Public Health Institute, Basel, Switzerland
- University of Basel, Basel, Switzerland
| | - Rasmus Jansson-Löfmark
- Unit for Pharmacokinetics and Drug Metabolism, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
- DMPK, Research and Early Development Cardiovascular, Renal and Metabolism, BioPharmaceuticals R&D, AstraZeneca, Gothenburg, Sweden
| | - Pascal Mäser
- Parasite Chemotherapy Unit, Department of Medical Parasitology and Infection Biology, Swiss Tropical and Public Health Institute, Basel, Switzerland
- University of Basel, Basel, Switzerland
| | - Michael Ashton
- Unit for Pharmacokinetics and Drug Metabolism, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
- * E-mail:
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21
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White NJ, Nosten FH. SERCAP: is the perfect the enemy of the good? Malar J 2021; 20:281. [PMID: 34167536 PMCID: PMC8223304 DOI: 10.1186/s12936-021-03821-z] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2021] [Accepted: 06/15/2021] [Indexed: 01/07/2023] Open
Abstract
Single Encounter Radical Cure and Prophylaxis (SERCAP) describes an ideal anti-malarial drug that cures all malaria in a single dose. This target product profile has dominated anti-malarial drug discovery and development over the past decade. The operational advantage of a single encounter has to be balanced against the need for a high dose, reliable absorption, little variability in pharmacokinetic properties, slow elimination (to ensure curative drug exposures in all patients) and a very low rate of vomiting. The demanding aspirational target may have hindered anti-malarial drug development. Aiming for three-day regimens, as in current anti-malarial treatments, would be better.
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Affiliation(s)
- Nicholas J White
- Mahidol Oxford Tropical Medicine Research Unit (MORU), Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand. .,Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, OX3 7BN, UK.
| | - François H Nosten
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, OX3 7BN, UK.,Shoklo Malaria Research Unit, MORU, Faculty of Tropical Medicine, Mahidol University, Mae Sot, Tak, Thailand
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22
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Ferreira Vieira MVD, Vieira JLF. Exposure to chloroquine in male adults and children aged 9-11 years with malaria due to Plasmodium vivax. Trans R Soc Trop Med Hyg 2021; 115:38-42. [PMID: 32838422 DOI: 10.1093/trstmh/traa079] [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] [Received: 04/14/2020] [Revised: 06/21/2020] [Accepted: 08/06/2020] [Indexed: 11/13/2022] Open
Abstract
BACKGROUND Chloroquine is effective against the asexual blood stage of Plasmodium vivax. A high proportion of children are underdosed with the drug, but there are no studies comparing chloroquine exposure in adults and children aged 8-11 years old. The present study intends to compare these populations using the area under the curve (AUC) derived from the plasma concentration-time profile in patients with P. vivax. METHODS A prospective study of cases was performed on male children (aged 9-11 years) and adults with vivax malaria. Blood samples were collected after several days of treatment. Chloroquine was measured by high-performance liquid chromatography. A non-compartmental pharmacokinetic model was used to calculate the pharmacokinetic parameters of the drug. RESULTS A total of 20 children and 25 adults were included in the study. Plasma concentrations of chloroquine in older children ranged from 67 to 1112 ng/ml, and in adults the value ranged from 74 to 1147 ng/ml. The AUC to the last measurable concentration and to infinite was significantly lower in children than in adults, indicating a lower exposure to the drug. CONCLUSION These data demonstrate lower exposure to chloroquine in children, which corroborates the importance of optimising the doses of chloroquine in the study age band to ensure adequate exposure to the drug.
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23
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Wilson JL, Cheung KWK, Lin L, Green EAE, Porrás AI, Zou L, Mukanga D, Akpa PA, Darko DM, Yuan R, Ding S, Johnson WCN, Lee HA, Cooke E, Peck CC, Kern SE, Hartman D, Hayashi Y, Marks PW, Altman RB, Lumpkin MM, Giacomini KM, Blaschke TF. Scientific considerations for global drug development. Sci Transl Med 2021; 12:12/554/eaax2550. [PMID: 32727913 DOI: 10.1126/scitranslmed.aax2550] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2019] [Revised: 06/05/2019] [Accepted: 11/05/2019] [Indexed: 12/12/2022]
Abstract
Requiring regional or in-country confirmatory clinical trials before approval of drugs already approved elsewhere delays access to medicines in low- and middle-income countries and raises drug costs. Here, we discuss the scientific and technological advances that may reduce the need for in-country or in-region clinical trials for drugs approved in other countries and limitations of these advances that could necessitate in-region clinical studies.
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Affiliation(s)
- Jennifer L Wilson
- Department of Bioengineering and Therapeutic Sciences, University of California, San Francisco, San Francisco, CA, USA
| | - Kit Wun Kathy Cheung
- Department of Bioengineering and Therapeutic Sciences, University of California, San Francisco, San Francisco, CA, USA
| | - Lawrence Lin
- Department of Bioengineering and Therapeutic Sciences, University of California, San Francisco, San Francisco, CA, USA
| | - Elizabeth A E Green
- Department of Bioengineering and Therapeutic Sciences, University of California, San Francisco, San Francisco, CA, USA
| | - Analia I Porrás
- Medicines and Health Technologies Unit, Department of Health Systems and Services, Pan American Health Organization, Regional Office of the World Health Organization, Washington, DC, USA
| | - Ling Zou
- Department of Bioengineering and Therapeutic Sciences, University of California, San Francisco, San Francisco, CA, USA
| | - David Mukanga
- Global Health, Bill and Melinda Gates Foundation, Seattle, WA, USA
| | - Paul A Akpa
- Department of Pharmaceutics, University of Nigeria, Nsukka, Enugu State, Nigeria
| | | | - Rae Yuan
- Sinovant Sciences Co., Shanghai, China
| | - Sheng Ding
- School of Pharmaceutical Sciences, Tsinghua University, Beijing, China.,Gladstone Institute of Cardiovascular Disease, San Francisco, CA, USA
| | | | - Howard A Lee
- Department of Clinical Pharmacology and Therapeutics, Seoul National University College of Medicine and Hospital, Seoul, Republic of Korea.,Department of Transdisciplinary Studies, Graduate School of Convergence Science and Technology, Seoul National University, Suwon, Republic of Korea
| | - Emer Cooke
- World Health Organization, Geneva, Switzerland
| | - Carl C Peck
- Department of Bioengineering and Therapeutic Sciences, University of California, San Francisco, San Francisco, CA, USA.,NDA Partners LLC, San Luis Obispo, CA, USA
| | - Steven E Kern
- Global Health, Bill and Melinda Gates Foundation, Seattle, WA, USA
| | - Dan Hartman
- Global Health, Bill and Melinda Gates Foundation, Seattle, WA, USA
| | | | - Peter W Marks
- Center for Biologics Evaluation and Research, U.S. Food and Drug Administration, Silver Spring, MD, USA
| | - Russ B Altman
- Departments of Bioengineering and Genetics, Stanford University, Stanford, CA, USA
| | - Murray M Lumpkin
- Global Health, Bill and Melinda Gates Foundation, Seattle, WA, USA
| | - Kathleen M Giacomini
- Department of Bioengineering and Therapeutic Sciences, University of California, San Francisco, San Francisco, CA, USA.
| | - Terrence F Blaschke
- Departments of Medicine and Molecular Pharmacology, Stanford University School of Medicine, Stanford, CA, USA
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24
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Buchter V, Hofmann D, Häberli C, Keiser J. Characterization of Moxidectin against Strongyloides ratti: In Vitro and In Vivo Activity and Pharmacokinetics in the Rat Model. ACS Infect Dis 2021; 7:1069-1076. [PMID: 32991142 DOI: 10.1021/acsinfecdis.0c00435] [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] [Indexed: 01/02/2023]
Abstract
Strongyloides stercoralis is a soil-transmitted helminth affecting an estimated 30-100 million people. Since the infection may be severe and life-threatening, accessible and effective treatment is pivotal. Currently, ivermectin is the drug of choice but has limitations. Moxidectin, a veterinary anthelminthic approved for use in human onchocerciasis, is a promising drug alternative against strongyloidiasis. In this study, we evaluated the in vitro activity of moxidectin on Strongyloides ratti larvae (L3) and adult females and the activity as well as the pharmacokinetics of moxidectin in S. ratti infected rats. In vitro, moxidectin had an activity that was similar to that of ivermectin, with median lethal concentration values for L3 and adults in the range of 0.08-1.44 μM, after 72 h of exposure. In vivo, doses of 250, 500, and 750 μg/kg of moxidectin resulted in a reduction of the worm burden ranging from 48.5 to 75%. At the highest dose (750 μg/kg) we observed a maximal blood concentration of 50.3 ng/mL and an area under the curve of 895.2 ng × h/mL. The half-life in rats was 9 h, and moxidectin was cleared to undetectable blood levels within 7 d (<10 ng/mL). No exposure-response relationship was observed. This work contributes to the characterization of moxidectin in the treatment of S. ratti as a model of Strongyloides spp. and, as such, supports moving moxidectin further along the drug development pipeline in the treatment of human strongyloidiasis.
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Affiliation(s)
- Valentin Buchter
- Swiss Tropical and Public Health Institute, Socinstrasse 57, P.O. Box, CH-4002 Basel, Switzerland
- University of Basel, Petersplatz 1, P.O. Box, CH-4001 Basel, Switzerland
| | - Daniela Hofmann
- Swiss Tropical and Public Health Institute, Socinstrasse 57, P.O. Box, CH-4002 Basel, Switzerland
- University of Basel, Petersplatz 1, P.O. Box, CH-4001 Basel, Switzerland
| | - Cécile Häberli
- Swiss Tropical and Public Health Institute, Socinstrasse 57, P.O. Box, CH-4002 Basel, Switzerland
- University of Basel, Petersplatz 1, P.O. Box, CH-4001 Basel, Switzerland
| | - Jennifer Keiser
- Swiss Tropical and Public Health Institute, Socinstrasse 57, P.O. Box, CH-4002 Basel, Switzerland
- University of Basel, Petersplatz 1, P.O. Box, CH-4001 Basel, Switzerland
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25
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Wang CYT, Ballard EL, Pava Z, Marquart L, Gaydon J, Murphy SC, Whiley D, O'Rourke P, McCarthy JS. Analytical validation of a real-time hydrolysis probe PCR assay for quantifying Plasmodium falciparum parasites in experimentally infected human adults. Malar J 2021; 20:181. [PMID: 33838672 PMCID: PMC8035755 DOI: 10.1186/s12936-021-03717-y] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2020] [Accepted: 03/29/2021] [Indexed: 11/10/2022] Open
Abstract
Background Volunteer infection studies have become a standard model for evaluating drug efficacy against Plasmodium infections. Molecular techniques such as qPCR are used in these studies due to their ability to provide robust and accurate estimates of parasitaemia at increased sensitivity compared to microscopy. The validity and reliability of assays need to be ensured when used to evaluate the efficacy of candidate drugs in clinical trials. Methods A previously described 18S rRNA gene qPCR assay for quantifying Plasmodium falciparum in blood samples was evaluated. Assay performance characteristics including analytical sensitivity, reportable range, precision, accuracy and specificity were assessed using experimental data and data compiled from phase 1 volunteer infection studies conducted between 2013 and 2019. Guidelines for validation of laboratory-developed molecular assays were followed. Results The reportable range was 1.50 to 6.50 log10 parasites/mL with a limit of detection of 2.045 log10 parasites/mL of whole blood based on a parasite diluted standard series over this range. The assay was highly reproducible with minimal intra-assay (SD = 0.456 quantification cycle (Cq) units [0.137 log10 parasites/mL] over 21 replicates) and inter-assay (SD = 0.604 Cq units [0.182 log10 parasites/mL] over 786 qPCR runs) variability. Through an external quality assurance program, the QIMR assay was shown to generate accurate results (quantitative bias + 0.019 log10 parasites/mL against nominal values). Specificity was 100% after assessing 164 parasite-free human blood samples. Conclusions The 18S rRNA gene qPCR assay is specific and highly reproducible and can provide reliable and accurate parasite quantification. The assay is considered fit for use in evaluating drug efficacy in malaria clinical trials. Supplementary Information The online version contains supplementary material available at 10.1186/s12936-021-03717-y.
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Affiliation(s)
- Claire Y T Wang
- Centre for Children's Health Research, Children's Health Queensland, Brisbane, Australia. .,Child Health Research Centre, The University of Queensland, Brisbane, Australia.
| | - Emma L Ballard
- QIMR Berghofer Medical Research Institute, Brisbane, Australia
| | - Zuleima Pava
- QIMR Berghofer Medical Research Institute, Brisbane, Australia
| | - Louise Marquart
- QIMR Berghofer Medical Research Institute, Brisbane, Australia
| | - Jane Gaydon
- Centre for Children's Health Research, Children's Health Queensland, Brisbane, Australia.,Child Health Research Centre, The University of Queensland, Brisbane, Australia
| | - Sean C Murphy
- Departments of Laboratory Medicine and Microbiology, University of Washington, Seattle, WA, USA.,Center for Emerging and Re-Emerging Infectious Diseases, University of Washington, Seattle, WA, USA
| | - David Whiley
- Centre for Children's Health Research, Children's Health Queensland, Brisbane, Australia.,UQ Centre for Clinical Research, Faculty of Medicine, The University of Queensland, Brisbane, Australia
| | - Peter O'Rourke
- QIMR Berghofer Medical Research Institute, Brisbane, Australia
| | - James S McCarthy
- QIMR Berghofer Medical Research Institute, Brisbane, Australia.,School of Medicine, The University of Queensland, Brisbane, Australia
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26
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van der Pluijm RW, Amaratunga C, Dhorda M, Dondorp AM. Triple Artemisinin-Based Combination Therapies for Malaria - A New Paradigm? Trends Parasitol 2020; 37:15-24. [PMID: 33060063 DOI: 10.1016/j.pt.2020.09.011] [Citation(s) in RCA: 52] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2020] [Revised: 09/18/2020] [Accepted: 09/19/2020] [Indexed: 01/31/2023]
Abstract
Recent gains in the fight against malaria are threatened by the emergence and spread of artemisinin and partner drug resistance in Plasmodium falciparum in the Greater Mekong Subregion (GMS). When artemisinins are combined with a single partner drug, all recommended artemisinin-based combination therapies have shown reduced efficacy in some countries in the GMS at some point. Novel drugs are not available for the near future. Triple artemisinin-based combination therapies, combining artemisinins with two currently available partner drugs, will provide one of the last remaining safe and effective treatments for falciparum malaria that can be deployed rapidly in the GMS, whereas their deployment beyond the GMS could delay or prevent the global emergence and spread of resistance to currently available drugs.
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Affiliation(s)
- Rob W van der Pluijm
- 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, UK
| | - Chanaki Amaratunga
- 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, UK
| | - Mehul Dhorda
- 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, UK; WorldWide Antimalarial Resistance Network - Asia-Pacific Regional Centre, Bangkok, Thailand
| | - Arjen M 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, UK.
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27
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Schalkwijk J, Allman EL, Jansen PAM, de Vries LE, Verhoef JMJ, Jackowski S, Botman PNM, Beuckens-Schortinghuis CA, Koolen KMJ, Bolscher JM, Vos MW, Miller K, Reeves SA, Pett H, Trevitt G, Wittlin S, Scheurer C, Sax S, Fischli C, Angulo-Barturen I, Jiménez-Diaz MB, Josling G, Kooij TWA, Bonnert R, Campo B, Blaauw RH, Rutjes FPJT, Sauerwein RW, Llinás M, Hermkens PHH, Dechering KJ. Antimalarial pantothenamide metabolites target acetyl-coenzyme A biosynthesis in Plasmodium falciparum. Sci Transl Med 2020; 11:11/510/eaas9917. [PMID: 31534021 DOI: 10.1126/scitranslmed.aas9917] [Citation(s) in RCA: 44] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2018] [Revised: 09/07/2018] [Accepted: 03/28/2019] [Indexed: 01/09/2023]
Abstract
Malaria eradication is critically dependent on new therapeutics that target resistant Plasmodium parasites and block transmission of the disease. Here, we report that pantothenamide bioisosteres were active against blood-stage Plasmodium falciparum parasites and also blocked transmission of sexual stages to the mosquito vector. These compounds were resistant to degradation by serum pantetheinases, showed favorable pharmacokinetic properties, and cleared parasites in a humanized mouse model of P. falciparum infection. Metabolomics revealed that coenzyme A biosynthetic enzymes converted pantothenamides into coenzyme A analogs that interfered with parasite acetyl-coenzyme A anabolism. Resistant parasites generated in vitro showed mutations in acetyl-coenzyme A synthetase and acyl-coenzyme A synthetase 11. Introduction and reversion of these mutations in P. falciparum using CRISPR-Cas9 gene editing confirmed the roles of these enzymes in the sensitivity of the malaria parasites to pantothenamides. These pantothenamide compounds with a new mode of action may have potential as drugs against malaria parasites.
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Affiliation(s)
- Joost Schalkwijk
- Department of Dermatology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, Netherlands.
| | - Erik L Allman
- Department of Biochemistry and Molecular Biology and Huck Center for Malaria Research, The Pennsylvania State University, University Park, PA 16802 USA
| | - Patrick A M Jansen
- Department of Dermatology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, Netherlands
| | - Laura E de Vries
- Department of Medical Microbiology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, Netherlands
| | - Julie M J Verhoef
- Department of Medical Microbiology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, Netherlands
| | | | | | | | | | | | | | - Karen Miller
- St. Jude Children's Research Hospital, Memphis, TN 38105, USA
| | - Stacy A Reeves
- St. Jude Children's Research Hospital, Memphis, TN 38105, USA
| | - Helmi Pett
- Department of Medical Microbiology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, Netherlands
| | | | - Sergio Wittlin
- Swiss Tropical and Public Health Institute, Basel, Switzerland.,University of Basel, Basel, Switzerland
| | - Christian Scheurer
- Swiss Tropical and Public Health Institute, Basel, Switzerland.,University of Basel, Basel, Switzerland
| | - Sibylle Sax
- Swiss Tropical and Public Health Institute, Basel, Switzerland.,University of Basel, Basel, Switzerland
| | - Christoph Fischli
- Swiss Tropical and Public Health Institute, Basel, Switzerland.,University of Basel, Basel, Switzerland
| | | | | | - Gabrielle Josling
- Department of Biochemistry and Molecular Biology and Huck Center for Malaria Research, The Pennsylvania State University, University Park, PA 16802 USA
| | - Taco W A Kooij
- Department of Medical Microbiology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, Netherlands
| | | | - Brice Campo
- Medicines for Malaria Venture, Geneva, Switzerland
| | | | | | - Robert W Sauerwein
- Department of Medical Microbiology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, Netherlands.,TropIQ Health Sciences, Nijmegen, Netherlands
| | - Manuel Llinás
- Department of Biochemistry and Molecular Biology and Huck Center for Malaria Research, The Pennsylvania State University, University Park, PA 16802 USA.,Department of Chemistry, The Pennsylvania State University, University Park, PA 16802 USA
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28
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Moore BR, Davis TM. Updated pharmacokinetic considerations for the use of antimalarial drugs in pregnant women. Expert Opin Drug Metab Toxicol 2020; 16:741-758. [PMID: 32729740 DOI: 10.1080/17425255.2020.1802425] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
INTRODUCTION The association between pregnancy and altered drug pharmacokinetic (PK) properties is acknowledged, as is its impact on drug plasma concentrations and thus therapeutic efficacy. However, there have been few robust PK studies of antimalarial use in pregnancy. Given that inadequate dosing for prevention or treatment of malaria in pregnancy can result in negative maternal/infant outcomes, along with the potential to select for parasite drug resistance, it is imperative that reliable pregnancy-specific dosing recommendations are established. AREAS COVERED PK studies of antimalarial drugs in pregnancy. The present review summarizes the efficacy and PK properties of WHO-recommended therapies used in pregnancy, with a focus on PK studies published since 2014. EXPERT OPINION Changes in antimalarial drug disposition in pregnancy are well described, yet pregnant women continue to receive treatment regimens optimized for non-pregnant adults. Contemporary in silico modeling has recently identified a series of alternative dosing regimens that are predicted to provide optimal therapeutic efficacy for pregnant women.
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Affiliation(s)
- Brioni R Moore
- School of Pharmacy and Biomedical Sciences, Curtin University , Bentley, Western Australia, Australia.,Medical School, University of Western Australia , Crawley, Western Australia, Australia
| | - Timothy M Davis
- Medical School, University of Western Australia , Crawley, Western Australia, Australia
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29
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Valéria Dias Ferreira M, Gabryelle Nunes Cardoso Mello A, Sena LWP, Regina Matos Lopes T, Luiz Fernandes Vieira J. The extent of chloroquine underdosing in adult patients with malaria by Plasmodium vivax from an endemic area of the Brazilian Amazon basin. Trop Med Int Health 2020; 25:1093-1097. [PMID: 32633099 DOI: 10.1111/tmi.13459] [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: 12/01/2022]
Abstract
OBJECTIVES To evaluate the extent of chloroquine underdosing and to measure the concentrations of chloroquine and desethylchloroquine in adult patients with P. vivax malaria in the Brazilian Amazon basin. METHODS Prospective study of cases in male adult patients with malaria by Plasmodium vivax treated with a total dose of 1500 mg chloroquine over three days and a short course of primaquine. Patients were weighed at admission, and the dose per mg/kg was determined. Blood samples were collected at 24 and 168 h after enrolment, and the concentrations of chloroquine and desethylchloroquine were measured in plasma by high-performance liquid chromatography with fluorescence detection. RESULTS Of 61 patients were included in the study, and 60% received a total dose of chloroquine below 25 mg/kg. Plasma chloroquine concentrations ranged from 90 to 184 ng/ml and from 175 to 827 ng/ml at 24 and 168 hours. For desethylchloroquine, the values ranged from 32 to 144 ng/ml and from 90 to 440 ng/ml at 24 and 168 h. There were no significant correlations between the plasma levels of chloroquine and the doses administered (mg/kg) at 24 and 196 h. Similar results were found for desethylchloroquine. CONCLUSION There is widespread suboptimal dosing of chloroquine that is probably due to the dosing regimen based on patient age, which reduces the drug exposure with a possible influence on parasite clearance.
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30
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Plasmodium falciparum ATP4 inhibitors to treat malaria: worthy successors to artemisinin? THE LANCET. INFECTIOUS DISEASES 2020; 20:883-885. [PMID: 32275871 DOI: 10.1016/s1473-3099(20)30139-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/07/2020] [Accepted: 02/18/2020] [Indexed: 11/20/2022]
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Karbwang J, Na‐Bangchang K. The Role of Clinical Pharmacology in Chemotherapy of Multidrug‐Resistant
Plasmodium falciparum. J Clin Pharmacol 2020; 60:830-847. [DOI: 10.1002/jcph.1589] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2019] [Accepted: 01/21/2020] [Indexed: 01/02/2023]
Affiliation(s)
- Juntra Karbwang
- Graduate Program in Bioclinical SciencesChulabhorn International College of MedicineThammasat University (Rangsit Campus) Pathumthani Thailand
- Center of Excellence in Pharmacology and Molecular Biology of Malaria and CholangiocarcinomaThammasat University (Rangsit Campus) Pathumthani Thailand
- Drug Discovery and Development Center, Office of Advanced Science and TechnologyThammasat University (Rangsit Campus) Pathumthani Thailand
- Department of Clinical Product developmentNagasaki Institute of Tropical MedicineNagasaki University Nagasaki Japan
| | - Kesara Na‐Bangchang
- Graduate Program in Bioclinical SciencesChulabhorn International College of MedicineThammasat University (Rangsit Campus) Pathumthani Thailand
- Center of Excellence in Pharmacology and Molecular Biology of Malaria and CholangiocarcinomaThammasat University (Rangsit Campus) Pathumthani Thailand
- Drug Discovery and Development Center, Office of Advanced Science and TechnologyThammasat University (Rangsit Campus) Pathumthani Thailand
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32
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Maan MK, Sattar A, Mi K, Bakr Shabbir MA, Xie S, Xin L, Ahmed S, Algharib SA, Huang L, Yuan Z. Integration of PK/PD for dose optimization of aditoprim against Trueperella pyogenes causing endometritis in bovines. Microb Pathog 2020; 142:104097. [PMID: 32105803 DOI: 10.1016/j.micpath.2020.104097] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2019] [Revised: 02/03/2020] [Accepted: 02/22/2020] [Indexed: 12/22/2022]
Abstract
Trueperella pyogenes is a major pathogenic organism of bovine uterus causing devastating economic losses. Clinical isolates of T. pyogenes demonstrated severe infection with high rate of disease progression than other pathogenic bacteria of uterus. We aimed to investigate the effectiveness of aditoprim, a novel dihydrofolate reductase inhibitor, based upon the ex-vivo pharmacodynamic analysis by using uterine fluid of cattle. In-vivo pharmacokinetic parameters were measured by high performance liquid choromatography and analyzed by winonline software (version 5.2.1). In-vitro minimum inhibitory concentration, mutant prevention concentration and time kill curves were determined with clinical isolates of Trueperell pyogenes. Our data showed that peak concentration (Cmax) and area under the concentration time curve (AUC) were 6551.43 ± 1296.13 and 23585.22 ± 5126.47 μg/mL, respectively. Aditoprim showed potent antimicrobial activity against T. pyogenes (MIC = 0.25 μg/mL) and exhibited the concentration dependent antibacterial effect and produced in-vitro post antibiotic effect which was less than 1 h and increased with concentration. Pharmacodynamics values were modeled with pharmacokinetics parameters (PK/PD modeling) to simulate the efficacy of aditoprim for different dosage regimens. It was concluded that a dose of 2 mg/kg every 12h was expected to reach a bactericidal activity against T. pyogenes in endometritis.
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Affiliation(s)
- Muhammad Kashif Maan
- National Reference Laboratory of Veterinary Drug Residues/ MAO Key Laboratory for the Detection of Veterinary Drug Residues, Huazhong Agricultural University, Wuhan, 430070, PR China
| | - Adeel Sattar
- Department of Pharmacology and Toxicology, Faculty of Biosciences, University of Veterinary and Animal Sciences, Lahore, Pakistan
| | - Kun Mi
- National Reference Laboratory of Veterinary Drug Residues/ MAO Key Laboratory for the Detection of Veterinary Drug Residues, Huazhong Agricultural University, Wuhan, 430070, PR China
| | - Muhammad Abu Bakr Shabbir
- Department of Microbiology, Faculty of Veterinary Medicine, University of Veterinary and Animal Sciences, Lahore, Pakistan
| | - Shuyu Xie
- National Reference Laboratory of Veterinary Drug Residues/ MAO Key Laboratory for the Detection of Veterinary Drug Residues, Huazhong Agricultural University, Wuhan, 430070, PR China
| | - Li Xin
- National Reference Laboratory of Veterinary Drug Residues/ MAO Key Laboratory for the Detection of Veterinary Drug Residues, Huazhong Agricultural University, Wuhan, 430070, PR China
| | - Saeed Ahmed
- National Reference Laboratory of Veterinary Drug Residues/ MAO Key Laboratory for the Detection of Veterinary Drug Residues, Huazhong Agricultural University, Wuhan, 430070, PR China
| | - Samah Attia Algharib
- National Reference Laboratory of Veterinary Drug Residues/ MAO Key Laboratory for the Detection of Veterinary Drug Residues, Huazhong Agricultural University, Wuhan, 430070, PR China
| | - Lingli Huang
- National Reference Laboratory of Veterinary Drug Residues/ MAO Key Laboratory for the Detection of Veterinary Drug Residues, Huazhong Agricultural University, Wuhan, 430070, PR China; MOA Laboratory for Risk Assessment of Quality and Safety of Livestock and Poultry Products, Huazhong Agricultural University, Wuhan, 430070, PR China.
| | - Zonghui Yuan
- National Reference Laboratory of Veterinary Drug Residues/ MAO Key Laboratory for the Detection of Veterinary Drug Residues, Huazhong Agricultural University, Wuhan, 430070, PR China; MOA Laboratory for Risk Assessment of Quality and Safety of Livestock and Poultry Products, Huazhong Agricultural University, Wuhan, 430070, PR China
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Charman SA, Andreu A, Barker H, Blundell S, Campbell A, Campbell M, Chen G, Chiu FCK, Crighton E, Katneni K, Morizzi J, Patil R, Pham T, Ryan E, Saunders J, Shackleford DM, White KL, Almond L, Dickins M, Smith DA, Moehrle JJ, Burrows JN, Abla N. An in vitro toolbox to accelerate anti-malarial drug discovery and development. Malar J 2020; 19:1. [PMID: 31898492 PMCID: PMC6941357 DOI: 10.1186/s12936-019-3075-5] [Citation(s) in RCA: 76] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2019] [Accepted: 12/14/2019] [Indexed: 01/08/2023] Open
Abstract
Background Modelling and simulation are being increasingly utilized to support the discovery and development of new anti-malarial drugs. These approaches require reliable in vitro data for physicochemical properties, permeability, binding, intrinsic clearance and cytochrome P450 inhibition. This work was conducted to generate an in vitro data toolbox using standardized methods for a set of 45 anti-malarial drugs and to assess changes in physicochemical properties in relation to changing target product and candidate profiles. Methods Ionization constants were determined by potentiometric titration and partition coefficients were measured using a shake-flask method. Solubility was assessed in biorelevant media and permeability coefficients and efflux ratios were determined using Caco-2 cell monolayers. Binding to plasma and media proteins was measured using either ultracentrifugation or rapid equilibrium dialysis. Metabolic stability and cytochrome P450 inhibition were assessed using human liver microsomes. Sample analysis was conducted by LC–MS/MS. Results Both solubility and fraction unbound decreased, and permeability and unbound intrinsic clearance increased, with increasing Log D7.4. In general, development compounds were somewhat more lipophilic than legacy drugs. For many compounds, permeability and protein binding were challenging to assess and both required the use of experimental conditions that minimized the impact of non-specific binding. Intrinsic clearance in human liver microsomes was varied across the data set and several compounds exhibited no measurable substrate loss under the conditions used. Inhibition of cytochrome P450 enzymes was minimal for most compounds. Conclusions This is the first data set to describe in vitro properties for 45 legacy and development anti-malarial drugs. The studies identified several practical methodological issues common to many of the more lipophilic compounds and highlighted areas which require more work to customize experimental conditions for compounds being designed to meet the new target product profiles. The dataset will be a valuable tool for malaria researchers aiming to develop PBPK models for the prediction of human PK properties and/or drug–drug interactions. Furthermore, generation of this comprehensive data set within a single laboratory allows direct comparison of properties across a large dataset and evaluation of changing property trends that have occurred over time with changing target product and candidate profiles.
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Affiliation(s)
- Susan A Charman
- Centre for Drug Candidate Optimisation, Monash Institute of Pharmaceutical Sciences, Monash University, 381 Royal Parade, Parkville, VIC, 3052, Australia.
| | - Alice Andreu
- Centre for Drug Candidate Optimisation, Monash Institute of Pharmaceutical Sciences, Monash University, 381 Royal Parade, Parkville, VIC, 3052, Australia
| | - Helena Barker
- Centre for Drug Candidate Optimisation, Monash Institute of Pharmaceutical Sciences, Monash University, 381 Royal Parade, Parkville, VIC, 3052, Australia
| | - Scott Blundell
- Centre for Drug Candidate Optimisation, Monash Institute of Pharmaceutical Sciences, Monash University, 381 Royal Parade, Parkville, VIC, 3052, Australia
| | - Anna Campbell
- Centre for Drug Candidate Optimisation, Monash Institute of Pharmaceutical Sciences, Monash University, 381 Royal Parade, Parkville, VIC, 3052, Australia
| | - Michael Campbell
- Centre for Drug Candidate Optimisation, Monash Institute of Pharmaceutical Sciences, Monash University, 381 Royal Parade, Parkville, VIC, 3052, Australia
| | - Gong Chen
- Centre for Drug Candidate Optimisation, Monash Institute of Pharmaceutical Sciences, Monash University, 381 Royal Parade, Parkville, VIC, 3052, Australia
| | - Francis C K Chiu
- Centre for Drug Candidate Optimisation, Monash Institute of Pharmaceutical Sciences, Monash University, 381 Royal Parade, Parkville, VIC, 3052, Australia
| | - Elly Crighton
- Centre for Drug Candidate Optimisation, Monash Institute of Pharmaceutical Sciences, Monash University, 381 Royal Parade, Parkville, VIC, 3052, Australia
| | - Kasiram Katneni
- Centre for Drug Candidate Optimisation, Monash Institute of Pharmaceutical Sciences, Monash University, 381 Royal Parade, Parkville, VIC, 3052, Australia
| | - Julia Morizzi
- Centre for Drug Candidate Optimisation, Monash Institute of Pharmaceutical Sciences, Monash University, 381 Royal Parade, Parkville, VIC, 3052, Australia
| | - Rahul Patil
- Centre for Drug Candidate Optimisation, Monash Institute of Pharmaceutical Sciences, Monash University, 381 Royal Parade, Parkville, VIC, 3052, Australia
| | - Thao Pham
- Centre for Drug Candidate Optimisation, Monash Institute of Pharmaceutical Sciences, Monash University, 381 Royal Parade, Parkville, VIC, 3052, Australia
| | - Eileen Ryan
- Centre for Drug Candidate Optimisation, Monash Institute of Pharmaceutical Sciences, Monash University, 381 Royal Parade, Parkville, VIC, 3052, Australia
| | - Jessica Saunders
- Centre for Drug Candidate Optimisation, Monash Institute of Pharmaceutical Sciences, Monash University, 381 Royal Parade, Parkville, VIC, 3052, Australia
| | - David M Shackleford
- Centre for Drug Candidate Optimisation, Monash Institute of Pharmaceutical Sciences, Monash University, 381 Royal Parade, Parkville, VIC, 3052, Australia
| | - Karen L White
- Centre for Drug Candidate Optimisation, Monash Institute of Pharmaceutical Sciences, Monash University, 381 Royal Parade, Parkville, VIC, 3052, Australia
| | - Lisa Almond
- Certara UK Limited, Simcyp Division, Level 2-Acero, 1 Concourse Way, Sheffield, S1 2BJ, UK
| | - Maurice Dickins
- Certara UK Limited, Simcyp Division, Level 2-Acero, 1 Concourse Way, Sheffield, S1 2BJ, UK
| | | | - Joerg J Moehrle
- Medicines for Malaria Venture, PO Box 1826, 20 Route de Pré-Bois, CH-1215, Geneva 15, Switzerland
| | - Jeremy N Burrows
- Medicines for Malaria Venture, PO Box 1826, 20 Route de Pré-Bois, CH-1215, Geneva 15, Switzerland
| | - Nada Abla
- Medicines for Malaria Venture, PO Box 1826, 20 Route de Pré-Bois, CH-1215, Geneva 15, Switzerland
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Nguyen HHT, Yeoh LM, Chisholm SA, Duffy MF. Developments in drug design strategies for bromodomain protein inhibitors to target Plasmodium falciparum parasites. Expert Opin Drug Discov 2019; 15:415-425. [PMID: 31870185 DOI: 10.1080/17460441.2020.1704251] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Introduction: Bromodomains (BRDs) bind to acetylated lysine residues, often on histones. The BRD proteins can contribute to gene regulation either directly through enzymatic activity or indirectly through recruitment of chromatin-modifying complexes or transcription factors. There is no evidence of direct orthologues of the Plasmodium falciparum BRD proteins (PfBDPs) outside the apicomplexans. PfBDPs are expressed during the parasite's life cycle in both the human host's blood and in the mosquito. PfBDPs could also prove to be promising targets for novel antimalarials, which are urgently required to address increasing drug resistance.Areas covered: This review discusses recent studies of the biology of PfBDPs, current target-based strategies for PfBDP inhibitor discovery, and different approaches to the important step of validating the specificity of hit compounds for PfBDPs.Expert opinion: The novelty of Plasmodium BRDs suggests that they could be targeted by selective compounds. Chemical series that showed promise in screens against human BRDs could be leveraged to create targeted compound libraries, as could hits from P. falciparum phenotypic screens. These targeted libraries and hits could be screened in target-based strategies aimed at discovery and optimization of novel inhibitors of PfBDPs. A key task for the field is to generate parasite assays to validate the hit compounds' specificity for PfBDPs.
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Affiliation(s)
- Hanh H T Nguyen
- The School of BioSciences, Bio21 Institute, The University of Melbourne, Melbourne, Australia.,The Dept of Medicine and Radiology, Royal Melbourne Hospital, University of Melbourne, Melbourne, Australia
| | - Lee M Yeoh
- The School of BioSciences, Bio21 Institute, The University of Melbourne, Melbourne, Australia
| | - Scott A Chisholm
- The School of BioSciences, Bio21 Institute, The University of Melbourne, Melbourne, Australia
| | - Michael F Duffy
- The School of BioSciences, Bio21 Institute, The University of Melbourne, Melbourne, Australia.,The Dept of Medicine and Radiology, Royal Melbourne Hospital, University of Melbourne, Melbourne, Australia
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Walz A, Leroy D, Andenmatten N, Mäser P, Wittlin S. Anti-malarial ozonides OZ439 and OZ609 tested at clinically relevant compound exposure parameters in a novel ring-stage survival assay. Malar J 2019; 18:427. [PMID: 31849323 PMCID: PMC6918666 DOI: 10.1186/s12936-019-3056-8] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2019] [Accepted: 12/07/2019] [Indexed: 11/20/2022] Open
Abstract
Background Drug efficacy against kelch 13 mutant malaria parasites can be determined in vitro with the ring-stage survival assay (RSA). The conventional assay protocol reflects the exposure profile of dihydroartemisinin. Methods Taking into account that other anti-malarial peroxides, such as the synthetic ozonides OZ439 (artefenomel) and OZ609, have different pharmacokinetics, the RSA was adjusted to the concentration–time profile of these ozonides in humans and a novel, semi-automated readout was introduced. Results When tested at clinically relevant parameters, it was shown that OZ439 and OZ609 are active against the Plasmodium falciparum clinical isolate Cam3.IR539T. Conclusion If the in vitro RSA does indeed predict the potency of compounds against parasites with increased tolerance to artemisinin and its derivatives, then the herein presented data suggest that following drug-pulses of at least 48 h, OZ439 and OZ609 will be highly potent against kelch 13 mutant isolates, such as P. falciparum Cam3.IR539T.
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Affiliation(s)
- Annabelle Walz
- Swiss Tropical and Public Health Institute, Socinstrasse 57, 4002, Basel, Switzerland.,University of Basel, Petersplatz 1, 4001, Basel, Switzerland
| | - Didier Leroy
- Medicines for Malaria Venture, Route de Pré Bois 20, 1215, Geneva, Switzerland
| | - Nicole Andenmatten
- Medicines for Malaria Venture, Route de Pré Bois 20, 1215, Geneva, Switzerland
| | - Pascal Mäser
- Swiss Tropical and Public Health Institute, Socinstrasse 57, 4002, Basel, Switzerland.,University of Basel, Petersplatz 1, 4001, Basel, Switzerland
| | - Sergio Wittlin
- Swiss Tropical and Public Health Institute, Socinstrasse 57, 4002, Basel, Switzerland. .,University of Basel, Petersplatz 1, 4001, Basel, Switzerland.
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Abstract
Intensified treatment and control efforts since the early 2000s have dramatically reduced the burden of Plasmodium falciparum malaria. However, drug resistance threatens to derail this progress. In this review, we present four antimalarial resistance case studies that differ in timeline, technical approaches, mechanisms of action, and categories of resistance: chloroquine, sulfadoxine-pyrimethamine, artemisinin, and piperaquine. Lessons learned from prior losses of treatment efficacy, drug combinations, and control strategies will help advance mechanistic research into how P. falciparum parasites acquire resistance to current first-line artemisinin-based combination therapies. Understanding resistance in the clinic and laboratory is essential to prolong the effectiveness of current antimalarial drugs and to optimize the pipeline of future medicines.
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Affiliation(s)
- Leila S Ross
- Department of Microbiology & Immunology, Columbia University Irving Medical Center, New York, NY 10032, USA
| | - David A Fidock
- Department of Microbiology & Immunology, Columbia University Irving Medical Center, New York, NY 10032, USA; Division of Infectious Diseases, Department of Medicine, Columbia University Irving Medical Center, New York, NY 10032, USA.
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Boareto AC, Gomes C, Centeno Müller J, da Silva JG, Vergara F, Salum N, Maristany Sargaço R, de Carvalho RR, Queiroz Telles JE, Marinho CRF, Paumgartten FJR, Dalsenter PR. Maternal and fetal outcome of pregnancy in Swiss mice infected with Plasmodium berghei ANKA GFP. Reprod Toxicol 2019; 89:107-114. [PMID: 31310803 DOI: 10.1016/j.reprotox.2019.07.011] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2019] [Revised: 06/19/2019] [Accepted: 07/12/2019] [Indexed: 11/19/2022]
Abstract
Malaria in pregnant women is associated with risk of maternal and perinatal morbidity and mortality, and there are few antimalarial drugs considered safe to treat them, so it is necessary to develop safer antimalarial medicines. The goal of this study was to develop an animal model for human malaria during pregnancy by characterizing the maternal and fetal outcomes in malaria infected Swiss mice. For that, in the present study, we evaluated the outcome of pregnancy in Swiss mice infected with Plasmodium berghei ANKAGFP. We observed a reduction of fetal body weight and signs of skeletal ossification retardation in the offspring of mice infected on GD 12. The group of mice infected with malaria presented premature deliveries and histopathology changes consistent with placental malaria. Our study suggests that Swiss Webster mice infected with P. berghei ANKAGFP on GD 12 might be a valuable model to investigate the safety and the efficacy of new antimalarial drugs indicated to pregnant women.
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Affiliation(s)
- Ana Cláudia Boareto
- Department of Pharmacology, Federal University of Paraná, Centro Politécnico, PO Box 19031, Curitiba, PR, 81531-980, Brazil.
| | - Caroline Gomes
- Department of Pharmacology, Federal University of Paraná, Centro Politécnico, PO Box 19031, Curitiba, PR, 81531-980, Brazil
| | - Juliane Centeno Müller
- Department of Pharmacology, Federal University of Paraná, Centro Politécnico, PO Box 19031, Curitiba, PR, 81531-980, Brazil
| | - Jonas Golart da Silva
- Department of Pharmacology, Federal University of Paraná, Centro Politécnico, PO Box 19031, Curitiba, PR, 81531-980, Brazil; Department of Chemistry and Biology, Federal University of Technology - Paraná, Cidade Industrial, Curitiba, PR, 81020-430, Brazil
| | - Fernanda Vergara
- Department of Pharmacology, Federal University of Paraná, Centro Politécnico, PO Box 19031, Curitiba, PR, 81531-980, Brazil
| | - Noruê Salum
- Department of Pharmacology, Federal University of Paraná, Centro Politécnico, PO Box 19031, Curitiba, PR, 81531-980, Brazil
| | - Rafaela Maristany Sargaço
- Department of Pharmacology, Federal University of Paraná, Centro Politécnico, PO Box 19031, Curitiba, PR, 81531-980, Brazil
| | - Rosângela Ribeiro de Carvalho
- Laboratory of Environmental Toxicology, National School of Public Health, Oswaldo Cruz Foundation, Manguinhos, Rio de Janeiro, RJ, 21041-210, Brazil
| | | | - Cláudio Romero Farias Marinho
- Department of Parasitology, Institute of Biomedical Sciences, University of São Paulo, Butantã, São Paulo, SP, 03178-200, Brazil
| | - Francisco José Roma Paumgartten
- Laboratory of Environmental Toxicology, National School of Public Health, Oswaldo Cruz Foundation, Manguinhos, Rio de Janeiro, RJ, 21041-210, Brazil
| | - Paulo Roberto Dalsenter
- Department of Pharmacology, Federal University of Paraná, Centro Politécnico, PO Box 19031, Curitiba, PR, 81531-980, Brazil
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Kannan D, Yadav N, Ahmad S, Namdev P, Bhattacharjee S, Lochab B, Singh S. Pre-clinical study of iron oxide nanoparticles fortified artesunate for efficient targeting of malarial parasite. EBioMedicine 2019; 45:261-277. [PMID: 31255656 PMCID: PMC6642363 DOI: 10.1016/j.ebiom.2019.06.026] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2019] [Revised: 06/01/2019] [Accepted: 06/13/2019] [Indexed: 12/13/2022] Open
Abstract
BACKGROUND Artesunate the most potent antimalarial is widely used for the treatment of multidrug-resistant malaria. The antimalarial cytotoxicity of artesunate has been mainly attributed to its selective, irreversible and iron- radical-mediated damage of parasite biomolecules. In the present research, iron oxide nanoparticle fortified artesunate was tested in P. falciparum and in an experimental malaria mouse model for enhancement in the selectivity and toxicity of artesunate towards parasite. Artesunate was fortified with nontoxic biocompatible surface modified iron oxide nanoparticle which is specially designed and synthesized for the sustained pH-dependent release of Fe2+ within the parasitic food vacuole for enhanced ROS spurt. METHODS Antimalarial efficacy of Iron oxide nanoparticle fortified artesunate was evaluated in wild type and artemisinin-resistant Plasmodium falciparum (R539T) grown in O + ve human blood and in Plasmodium berghei ANKA infected swiss albino mice. Internalization of nanoparticles, the pH-dependent release of Fe2+, production of reactive oxygen species and parasite biomolecule damage by iron oxide nanoparticle fortified artesunate was studied using various biochemical, biophysical, ultra-structural and fluorescence microscopy. For determining the efficacy of ATA-IONP+ART on resistant parasite ring survival assay was performed. RESULTS The nanoparticle fortified artesunate was highly efficient in the 1/8th concentration of artesunate IC50 and led to retarded growth of P. falciparum with significant damage to macromolecules mediated via enhanced ROS production. Similarly, preclinical In vivo studies also signified a radical reduction in parasitemia with ~8-10-fold reduced dosage of artesunate when fortified with iron oxide nanoparticles. Importantly, the ATA-IONP combination was efficacious against artemisinin-resistant parasites. INTERPRETATION Surface coated iron-oxide nanoparticle fortified artesunate can be developed into a potent therapeutic agent towards multidrug-resistant and artemisinin-resistant malaria in humans. FUND: This study is supported by the Centre for Study of Complex Malaria in India funded by the National Institute of Health, USA.
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Affiliation(s)
- Deepika Kannan
- Department of Life Sciences, School of Natural Sciences, Shiv Nadar University, Gautam Buddha Nagar, India
| | - Nisha Yadav
- Department of Chemistry, School of Natural Sciences, Shiv Nadar University, Gautam Buddha Nagar, India
| | - Shakeel Ahmad
- Special Center for Molecular Medicine, Jawaharlal Nehru University, New Mehrauli Road, New Delhi, India
| | - Pragya Namdev
- Special Center for Molecular Medicine, Jawaharlal Nehru University, New Mehrauli Road, New Delhi, India
| | - Souvik Bhattacharjee
- Special Center for Molecular Medicine, Jawaharlal Nehru University, New Mehrauli Road, New Delhi, India
| | - Bimlesh Lochab
- Department of Chemistry, School of Natural Sciences, Shiv Nadar University, Gautam Buddha Nagar, India.
| | - Shailja Singh
- Special Center for Molecular Medicine, Jawaharlal Nehru University, New Mehrauli Road, New Delhi, India.
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Superior Pyronaridine Single-Dose Pharmacodynamics Compared to Artesunate, Chloroquine, and Amodiaquine in a Murine Malaria Luciferase Model. Antimicrob Agents Chemother 2018; 62:AAC.00394-18. [PMID: 29967019 DOI: 10.1128/aac.00394-18] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2018] [Accepted: 06/15/2018] [Indexed: 11/20/2022] Open
Abstract
Many previous in vitro and in vivo preclinical malaria drug studies have relied on low-parasite-number drug inhibition numerically compared to the untreated controls. In contrast, human malaria drug studies measure the high-parasite-density killing near 100 million/ml. Here we compared the in vivo single-dose pharmacodynamic properties of artesunate and the 4-aminoquinolines pyronaridine, chloroquine, and amodiaquine in a Plasmodium berghei ANKA-green fluorescent protein GFP-luciferase-based murine malaria blood-stage model. Pyronaridine exhibited dose-dependent killing, achieving parasite reductions near 5 to 6 logs at 48 h, with complete cure at 10 mg/kg of body weight compared to artesunate, which exhibited a 48-h dose-dependent killing with a 2-log drop at the noncurative 250-mg/kg dose. Chloroquine, which was noncurative, and amodiaquine, which was partially curative, had nearly the same initial dose-independent killing, with a lag phase of minimal parasite reduction at all doses between 6 and 24 h, followed by a 2.5-log reduction at 48 h. In experiments with drug-treated, washed infected blood transfer to naive mice, chloroquine and amodiaquine showed fewer viable parasites at the 24-h transfer than at the 8-h transfer, measured by a prolonged return to parasitemia, despite a similar parasite log reduction at these time points, in contrast to the correlation of the parasite log reduction to viable parasites with artesunate and pyronaridine. Artesunate in combination with pyronaridine exhibited an initial parasite reduction similar to that achieved with pyronaridine, while with chloroquine or amodiaquine, the reduction was similar to that achieved with artesunate. Single-oral-dose pyronaridine was much more potent in vivo than artesunate, chloroquine, and amodiaquine during the initial decline in parasites and cure.
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40
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Scott N, Ataide R, Wilson DP, Hellard M, Price RN, Simpson JA, Fowkes FJI. Implications of population-level immunity for the emergence of artemisinin-resistant malaria: a mathematical model. Malar J 2018; 17:279. [PMID: 30071877 PMCID: PMC6071336 DOI: 10.1186/s12936-018-2418-y] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2018] [Accepted: 07/12/2018] [Indexed: 01/12/2023] Open
Abstract
BACKGROUND Artemisinin-resistant Plasmodium falciparum has emerged in the Greater Mekong Subregion, an area of relatively low transmission, but has yet to be reported in Africa. A population-based mathematical model was used to investigate the relationship between P. falciparum prevalence, exposure-acquired immunity and time-to-emergence of artemisinin resistance. The possible implication for the emergence of resistance across Africa was assessed. METHODS The model included human and mosquito populations, two strains of malaria ("wild-type", "mutant"), three levels of human exposure-acquired immunity (none, low, high) with two types of immunity for each level (sporozoite/liver stage immunity and blood-stage/gametocyte immunity) and drug pressure based on per-capita treatment numbers. RESULTS The model predicted that artemisinin-resistant strains may circulate up to 10 years longer in high compared to low P. falciparum prevalence areas before resistance is confirmed. Decreased time-to-resistance in low prevalence areas was explained by low genetic diversity and immunity, which resulted in increased probability of selection and spread of artemisinin-resistant strains. Artemisinin resistance was estimated to be established by 2020 in areas of Africa with low (< 10%) P. falciparum prevalence, but not for 5 or 10 years later in moderate (10-25%) or high (> 25%) prevalence areas, respectively. CONCLUSIONS Areas of low transmission and low immunity give rise to a more rapid expansion of artemisinin-resistant parasites, corroborating historical observations of anti-malarial resistance emergence. Populations where control strategies are in place that reduce malaria transmission, and hence immunity, may be prone to a rapid emergence and spread of artemisinin-resistant strains and thus should be carefully monitored.
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Affiliation(s)
- Nick Scott
- Disease Elimination Program, Burnet Institute, Melbourne, VIC, 3004, Australia
- Department of Epidemiology and Preventive Medicine, Monash University, Melbourne, VIC, 3004, Australia
| | - Ricardo Ataide
- Disease Elimination Program, Burnet Institute, Melbourne, VIC, 3004, Australia
| | - David P Wilson
- Disease Elimination Program, Burnet Institute, Melbourne, VIC, 3004, Australia
- Department of Epidemiology and Preventive Medicine, Monash University, Melbourne, VIC, 3004, Australia
| | - Margaret Hellard
- Disease Elimination Program, Burnet Institute, Melbourne, VIC, 3004, Australia
- Department of Epidemiology and Preventive Medicine, Monash University, Melbourne, VIC, 3004, Australia
- Department of Infectious Diseases, Alfred Hospital, Melbourne, VIC, 3004, Australia
| | - Ric N Price
- Global and Tropical Health Division, Menzies School of Health Research, Charles Darwin University, Darwin, NT, Australia
- Centre for Tropical Medicine and Global Health, Nuffield Department of Clinical Medicine, University of Oxford, Oxford, UK
| | - Julie A Simpson
- Centre for Epidemiology and Biostatistics, Melbourne School of Population and Global Health, The University of Melbourne, Melbourne, VIC, 3010, Australia
| | - Freya J I Fowkes
- Disease Elimination Program, Burnet Institute, Melbourne, VIC, 3004, Australia.
- Department of Epidemiology and Preventive Medicine, Monash University, Melbourne, VIC, 3004, Australia.
- Centre for Epidemiology and Biostatistics, Melbourne School of Population and Global Health, The University of Melbourne, Melbourne, VIC, 3010, Australia.
- Department of Infectious Diseases, Monash University, Melbourne, VIC, 3004, Australia.
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Characterizing Blood-Stage Antimalarial Drug MIC Values In Vivo Using Reinfection Patterns. Antimicrob Agents Chemother 2018; 62:AAC.02476-17. [PMID: 29661873 PMCID: PMC6021672 DOI: 10.1128/aac.02476-17] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2017] [Accepted: 03/27/2018] [Indexed: 12/01/2022] Open
Abstract
The MIC is an essential quantitative measure of the asexual blood-stage effect of an antimalarial drug. In areas of high malaria transmission, and thus frequent individual infection, patients who are treated with slowly eliminated antimalarials become reinfected as drug concentrations decline. In the frequent relapse forms of Plasmodium vivax and in Plasmodium ovale malaria, recurrent infection occurs from relapses which begin to emerge from the liver approximately 2 weeks after the primary illness. An important determinant of the interval from starting treatment of a symptomatic infection to the patency of these recurrent infections is the in vivo concentration-response relationship and thus the in vivo MIC. Using mechanistic knowledge of parasite asexual replication and the pharmacokinetic and pharmacodynamic properties of the antimalarial drugs, a generative statistical model was derived which relates the concentration-response relationship to time of reinfection patency. This model was used to estimate the in vivo MIC of chloroquine in the treatment of Plasmodium vivax malaria.
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Nsanzabana C, Djalle D, Guérin PJ, Ménard D, González IJ. Tools for surveillance of anti-malarial drug resistance: an assessment of the current landscape. Malar J 2018; 17:75. [PMID: 29422048 PMCID: PMC5806256 DOI: 10.1186/s12936-018-2185-9] [Citation(s) in RCA: 46] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2017] [Accepted: 01/10/2018] [Indexed: 12/12/2022] Open
Abstract
To limit the spread and impact of anti-malarial drug resistance and react accordingly, surveillance systems able to detect and track in real-time its emergence and spread need to be strengthened or in some places established. Currently, surveillance of anti-malarial drug resistance is done by any of three approaches: (1) in vivo studies to assess the efficacy of drugs in patients; (2) in vitro/ex vivo studies to evaluate parasite susceptibility to the drugs; and/or (3) molecular assays to detect validated gene mutations and/or gene copy number changes that are associated with drug resistance. These methods are complementary, as they evaluate different aspects of resistance; however, standardization of methods, especially for in vitro/ex vivo and molecular techniques, is lacking. The World Health Organization has developed a standard protocol for evaluating the efficacy of anti-malarial drugs, which is used by National Malaria Control Programmes to conduct their therapeutic efficacy studies. Regional networks, such as the East African Network for Monitoring Antimalarial Treatment and the Amazon Network for the Surveillance of Antimalarial Drug Resistance, have been set up to strengthen regional capacities for monitoring anti-malarial drug resistance. The Worldwide Antimalarial Resistance Network has been established to collate and provide global spatial and temporal trends information on the efficacy of anti-malarial drugs and resistance. While exchange of information across endemic countries is essential for monitoring anti-malarial resistance, sustainable funding for the surveillance and networking activities remains challenging. The technology landscape for molecular assays is progressing quite rapidly, and easy-to-use and affordable new techniques are becoming available. They also offer the advantage of high throughput analysis from a simple blood spots obtained from a finger prick. New technologies combined with the strengthening of national reference laboratories in malaria-endemic countries through standardized protocols and training plus the availability of a proficiency testing programme, would contribute to the improvement and sustainability of anti-malarial resistance surveillance networks worldwide.
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Affiliation(s)
| | - Djibrine Djalle
- Foundation for Innovative New Diagnostics (FIND), Geneva, Switzerland
| | - Philippe J Guérin
- WorldWide Antimalarial Resistance Network, Oxford, UK.,Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Didier Ménard
- Unité Biologie des Interactions Hôte-Parasite, Institut Pasteur, Paris, France
| | - Iveth J González
- Foundation for Innovative New Diagnostics (FIND), Geneva, Switzerland
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43
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Dechering KJ, Duerr HP, Koolen KMJ, Gemert GJV, Bousema T, Burrows J, Leroy D, Sauerwein RW. Modelling mosquito infection at natural parasite densities identifies drugs targeting EF2, PI4K or ATP4 as key candidates for interrupting malaria transmission. Sci Rep 2017; 7:17680. [PMID: 29247222 PMCID: PMC5732164 DOI: 10.1038/s41598-017-16671-0] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2017] [Accepted: 11/16/2017] [Indexed: 11/25/2022] Open
Abstract
Eradication of malaria requires a novel type of drug that blocks transmission from the human to the mosquito host, but selection of such a drug is hampered by a lack of translational models. Experimental mosquito infections yield infection intensities that are substantially higher than observed in natural infections and, as a consequence, underestimate the drug effect on the proportion of mosquitoes that become infected. Here we introduce a novel experimental and computational method to adequately describe drug efficacy at natural parasite densities. Parameters of a beta-binomial infection model were established and validated using a large number of experimental mosquito infections at different parasite densities. Analyses of 15 experimental and marketed drugs revealed a class-specific ability to block parasite transmission. Our results highlight the parasite's elongation factor EF2, PI4 kinase and the ATP4 sodium channel as key targets for interruption of transmission, and compounds DDD107498 and KAE609 as most advanced drug candidates.
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Affiliation(s)
- Koen J Dechering
- TropIQ Health Sciences, Transistorweg 5-C02, 6534AT, Nijmegen, The Netherlands.
| | | | - Karin M J Koolen
- TropIQ Health Sciences, Transistorweg 5-C02, 6534AT, Nijmegen, The Netherlands
| | - Geert-Jan van Gemert
- Radboud University Medical Center, PO Box 9101, 6500 HB, Nijmegen, The Netherlands
| | - Teun Bousema
- Radboud University Medical Center, PO Box 9101, 6500 HB, Nijmegen, The Netherlands
| | - Jeremy Burrows
- Medicines for Malaria Venture, Route de Pré-Bois 20, 1215, Geneva, 15, Switzerland
| | - Didier Leroy
- Medicines for Malaria Venture, Route de Pré-Bois 20, 1215, Geneva, 15, Switzerland
| | - Robert W Sauerwein
- TropIQ Health Sciences, Transistorweg 5-C02, 6534AT, Nijmegen, The Netherlands
- Radboud University Medical Center, PO Box 9101, 6500 HB, Nijmegen, The Netherlands
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44
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Zhang M, Gallego-Delgado J, Fernandez-Arias C, Waters NC, Rodriguez A, Tsuji M, Wek RC, Nussenzweig V, Sullivan WJ. Inhibiting the Plasmodium eIF2α Kinase PK4 Prevents Artemisinin-Induced Latency. Cell Host Microbe 2017; 22:766-776.e4. [DOI: 10.1016/j.chom.2017.11.005] [Citation(s) in RCA: 71] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2017] [Revised: 09/26/2017] [Accepted: 11/10/2017] [Indexed: 01/09/2023]
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45
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A Dynamic Stress Model Explains the Delayed Drug Effect in Artemisinin Treatment of Plasmodium falciparum. Antimicrob Agents Chemother 2017; 61:AAC.00618-17. [PMID: 28993326 PMCID: PMC5700357 DOI: 10.1128/aac.00618-17] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2017] [Accepted: 09/28/2017] [Indexed: 01/23/2023] Open
Abstract
Artemisinin resistance constitutes a major threat to the continued success of control programs for malaria, particularly in light of developing resistance to partner drugs. Improving our understanding of how artemisinin-based drugs act and how resistance manifests is essential for the optimization of dosing regimens and the development of strategies to prolong the life span of current first-line treatment options. Recent short-drug-pulse in vitro experiments have shown that the parasite killing rate depends not only on drug concentration but also the exposure time, challenging the standard pharmacokinetic-pharmacodynamic (PK-PD) paradigm in which the killing rate depends only on drug concentration. Here, we introduce a dynamic stress model of parasite killing and show through application to 3D7 laboratory strain viability data that the inclusion of a time-dependent parasite stress response dramatically improves the model's explanatory power compared to that of a traditional PK-PD model. Our model demonstrates that the previously reported hypersensitivity of early-ring-stage parasites of the 3D7 strain to dihydroartemisinin compared to other parasite stages is due primarily to a faster development of stress rather than a higher maximum achievable killing rate. We also perform in vivo simulations using the dynamic stress model and demonstrate that the complex temporal features of artemisinin action observed in vitro have a significant impact on predictions for in vivo parasite clearance. Given the important role that PK-PD models play in the design of clinical trials for the evaluation of alternative drug dosing regimens, our novel model will contribute to the further development and improvement of antimalarial therapies.
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46
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Olafuyi O, Coleman M, Badhan RK. The application of physiologically based pharmacokinetic modelling to assess the impact of antiretroviral-mediated drug-drug interactions on piperaquine antimalarial therapy during pregnancy. Biopharm Drug Dispos 2017; 38:464-478. [DOI: 10.1002/bdd.2087] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2017] [Revised: 06/22/2017] [Accepted: 07/06/2017] [Indexed: 12/19/2022]
Affiliation(s)
- Olusola Olafuyi
- Aston Healthy Research Group, Aston Pharmacy School; Aston University; Birmingham B4 7ET UK
| | - Michael Coleman
- Aston Pharmacy School; Aston University; Birmingham B4 7ET UK
| | - Raj K.S. Badhan
- Aston Healthy Research Group, Aston Pharmacy School; Aston University; Birmingham B4 7ET UK
- Aston Pharmacy School; Aston University; Birmingham B4 7ET UK
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47
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Blasco B, Leroy D, Fidock DA. Antimalarial drug resistance: linking Plasmodium falciparum parasite biology to the clinic. Nat Med 2017; 23:917-928. [PMID: 28777791 DOI: 10.1038/nm.4381] [Citation(s) in RCA: 325] [Impact Index Per Article: 46.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2017] [Accepted: 06/30/2017] [Indexed: 02/08/2023]
Abstract
The global adoption of artemisinin-based combination therapies (ACTs) in the early 2000s heralded a new era in effectively treating drug-resistant Plasmodium falciparum malaria. However, several Southeast Asian countries have now reported the emergence of parasites that have decreased susceptibility to artemisinin (ART) derivatives and ACT partner drugs, resulting in increasing rates of treatment failures. Here we review recent advances in understanding how antimalarials act and how resistance develops, and discuss new strategies for effectively combatting resistance, optimizing treatment and advancing the global campaign to eliminate malaria.
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Affiliation(s)
| | - Didier Leroy
- Medicines for Malaria Venture, Geneva, Switzerland
| | - David A Fidock
- Department of Microbiology and Immunology, Columbia University Medical Center, New York, New York, USA.,Division of Infectious Diseases, Department of Medicine, Columbia University Medical Center, New York, New York, USA
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48
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Kadam PP, Gogtay NJ, Karande S, Shah V, Thatte UM. Evaluation of pharmacokinetics of single-dose chloroquine in malnourished children with malaria- a comparative study with normally nourished children. Indian J Pharmacol 2017; 48:498-502. [PMID: 27721533 PMCID: PMC5051241 DOI: 10.4103/0253-7613.190720] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
Abstract
OBJECTIVES Studies on antimalarial kinetics in children or adults who are undernourished or malnourished are both limited and have yielded conflicting results. The present study was carried out with the objectives of evaluating the pharmacokinetics of single dose chloroquine and its metabolite desethylchloroquine in children who were undernourished and compare them with children who were normally nourished. METHODS Children of either gender between the ages of 5 and 12 years, smear positive for P. vivax malaria and classified either as well nourished or undernourished were included. Undernourishment was adjudged based on the Indian Academy of Pediatrics (IAP) classification of protein energy malnutrition [PEM] which in turn was based on Khadilkar's growth charts. All participants received 10 mg/kg on the first day followed by 10 mg/kg on Day 2 and 5 mg/kg on Day 3 along with supportive treatment. Blood samples for the levels of chloroquine [CQ] and desethylchloroquine [DECQ] were collected at 0, 0.5, 1, 2 4, 8, 12, 24, 48, 72 hours and 14 days after the first dose and levels assessed by High Performance Liquid Chromatography. RESULTS A total of 12 children who were normally nourished and 13 who were undernourished were studied. Wide inter-individual variability was seen in the levels of both drug and metabolite in both groups of patients. However, the differences in Cmax, AUC 0-inf, Clearance, half life and Vd between the two groups were not significantly different. DISCUSSION Our results indicate that dosage requirement is unlikely to be needed for chloroquine in undernourished children with uncomplicated P. vivax malaria.
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Affiliation(s)
- Prashant P Kadam
- Department of Clinical Pharmacology, Seth GS Medical College and KEM Hospital, Mumbai, Maharashtra, India
| | - Nithya Jaideep Gogtay
- Department of Clinical Pharmacology, Seth GS Medical College and KEM Hospital, Mumbai, Maharashtra, India
| | - Sunil Karande
- Department of Pediatrics, Seth GS Medical College and KEM Hospital, Mumbai, Maharashtra, India
| | - V Shah
- Department of Pediatrics, Seth GS Medical College and KEM Hospital, Mumbai, Maharashtra, India
| | - Urmila M Thatte
- Department of Clinical Pharmacology, Seth GS Medical College and KEM Hospital, Mumbai, Maharashtra, India
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49
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Long-Term Prophylaxis and Pharmacokinetic Evaluation of Intramuscular Nano- and Microparticle Decoquinate in Mice Infected with P. berghei Sporozoites. Malar Res Treat 2017; 2017:7508291. [PMID: 28491482 PMCID: PMC5406721 DOI: 10.1155/2017/7508291] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2016] [Accepted: 01/31/2017] [Indexed: 11/17/2022] Open
Abstract
Decoquinate nanoparticle and microparticle suspended in an oily vehicle to retard drug release are evaluated for long-term malaria prophylaxis. Pharmacokinetic studies in normal animals and antimalarial efficacy in liver stage malaria mice were conducted at various single intramuscular-decoquinate doses for 2, 4, 6, or 8 weeks prior to infection with P. berghei sporozoites. The liver stage efficacy evaluation was monitored by using an in vivo imaging system. Full causal prophylaxis was shown in mice with a single intramuscular dose at 120 mg/kg of nanoparticle decoquinate (0.43 μm) for 2-3 weeks and with microparticle decoquinate (8.31 μm) injected 8 weeks earlier than inoculation. The time above MIC of 1,375 hr observed with the microparticle formulation provided a 2.2-fold longer drug exposure than with the nanoparticle formulation (624 hr). The prophylactic effect of the microparticle formulation observed in mice was shown to be 3-4 times longer than the nanoparticle decoquinate formulation.
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50
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Ashley E. Investment in antimalarial drug development is bearing fruit. THE LANCET. INFECTIOUS DISEASES 2017; 17:568-570. [PMID: 28363638 DOI: 10.1016/s1473-3099(17)30172-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/03/2017] [Accepted: 03/03/2017] [Indexed: 10/19/2022]
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