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Gansane A, Lingani M, Yeka A, Nahum A, Bouyou-Akotet M, Mombo-Ngoma G, Kaguthi G, Barceló C, Laurijssens B, Cantalloube C, Macintyre F, Djeriou E, Jessel A, Bejuit R, Demarest H, Marrast AC, Debe S, Tinto H, Kibuuka A, Nahum D, Mawili-Mboumba DP, Zoleko-Manego R, Mugenya I, Olewe F, Duparc S, Ogutu B. Randomized, open-label, phase 2a study to evaluate the contribution of artefenomel to the clinical and parasiticidal activity of artefenomel plus ferroquine in African patients with uncomplicated Plasmodium falciparum malaria. Malar J 2023; 22:2. [PMID: 36597076 PMCID: PMC9809015 DOI: 10.1186/s12936-022-04420-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2022] [Accepted: 12/16/2022] [Indexed: 01/05/2023] Open
Abstract
BACKGROUND The contribution of artefenomel to the clinical and parasiticidal activity of ferroquine and artefenomel in combination in uncomplicated Plasmodium falciparum malaria was investigated. METHODS This Phase 2a, randomized, open-label, parallel-group study was conducted from 11th September 2018 to 6th November 2019 across seven centres in Benin, Burkina Faso, Gabon, Kenya, and Uganda. Patients aged ≥ 14-69 years with microscopically confirmed infection (≥ 3000 to ≤ 50,000 parasites/µL blood) were randomized 1:1:1:1 to 400 mg ferroquine, or 400 mg ferroquine plus artefenomel 300, 600, or 1000 mg, administered as a single oral dose. The primary efficacy analysis was a logistic regression evaluating the contribution of artefenomel exposure to Day 28 PCR-adjusted adequate clinical and parasitological response (ACPR). Safety was also evaluated. RESULTS The randomized population included 140 patients. For the primary analysis in the pharmacokinetic/pharmacodynamic efficacy population (N = 121), the contribution of artefenomel AUC0-∞ to Day 28 PCR-adjusted ACPR was not demonstrated when accounting for ferroquine AUC0-d28, baseline parasitaemia, and other model covariates: odds ratio 1.1 (95% CI 0.98, 1.2; P = 0.245). In the per-protocol population, Day 28 PCR-adjusted ACPR was 80.8% (21/26; 95% CI 60.6, 93.4) with ferroquine alone and 90.3% (28/31; 95% CI 74.2, 98.0), 90.9% (30/33; 95% CI 75.7, 98.1) and 87.1% (27/31; 95% CI 70.2, 96.4) with 300, 600, and 1000 mg artefenomel, respectively. Median time to parasite clearance (Kaplan-Meier) was 56.1 h with ferroquine, more rapid with artefenomel, but similar for all doses (30.0 h). There were no deaths. Adverse events (AEs) of any cause occurred in 51.4% (18/35) of patients with ferroquine 400 mg alone, and 58.3% (21/36), 66.7% (24/36), and 72.7% (24/33) with 300, 600, and 1000 mg artefenomel, respectively. All AEs were of mild-to-moderate severity, and consistent with the known profiles of the compounds. Vomiting was the most reported AE. There were no cases of QTcF prolongation ≥ 500 ms or > 60 ms from baseline. CONCLUSION The contribution of artefenomel exposure to the clinical and parasitological activity of ferroquine/artefenomel could not be demonstrated in this study. Parasite clearance was faster with ferroquine/artefenomel versus ferroquine alone. All treatments were well tolerated. TRIAL REGISTRATION ClinicalTrials.gov, NCT03660839 (7 September, 2018).
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Affiliation(s)
- Adama Gansane
- grid.507461.10000 0004 0413 3193Centre National de Recherche et de Formation sur le Paludisme (CNRFP), 01 BP 220801 BP 2208 Ouagadougou, Burkina Faso
| | - Moussa Lingani
- grid.457337.10000 0004 0564 0509Institut de Recherche en Science de la Santé - Unité de Recherche Clinique de Nanoro (IRSS-URCN), Ouagadougou, Burkina Faso
| | - Adoke Yeka
- grid.463352.50000 0004 8340 3103Infectious Diseases Research Collaboration (IDRC), Kampala, Uganda
| | - Alain Nahum
- Centre de Recherches Entomologique de Cotonou (CREC), Cotonou, Benin
| | - Marielle Bouyou-Akotet
- grid.502965.dDépartement de Parasitologie-Mycologie-Médecine Tropicale, Faculté de Médecine – Université des Sciences de la Santé, Libreville, Gabon
| | - Ghyslain Mombo-Ngoma
- grid.452268.fCentre de Recherches Médicales de Lambaréné (CERMEL), Lambaréné, Gabon ,Department of Tropical Medicine, Bernhard Nocht Institute for Tropical Medicine, and University Medical Center Hamburg-Eppendorf, Hamburg, Germany ,grid.10392.390000 0001 2190 1447Institute for Tropical Medicine, University of Tübingen, Tübingen, Germany
| | - Grace Kaguthi
- grid.33058.3d0000 0001 0155 5938Kenya Medical Research Institute-Centre for Respiratory Diseases Research (KEMRI-CRDR), Nairobi, Kenya
| | - Catalina Barceló
- grid.452605.00000 0004 0432 5267Medicines for Malaria Venture, Geneva, Switzerland
| | | | | | - Fiona Macintyre
- grid.452605.00000 0004 0432 5267Medicines for Malaria Venture, Geneva, Switzerland
| | | | | | | | - Helen Demarest
- grid.452605.00000 0004 0432 5267Medicines for Malaria Venture, Geneva, Switzerland
| | - Anne Claire Marrast
- grid.452605.00000 0004 0432 5267Medicines for Malaria Venture, Geneva, Switzerland
| | - Siaka Debe
- grid.507461.10000 0004 0413 3193Centre National de Recherche et de Formation sur le Paludisme (CNRFP), 01 BP 220801 BP 2208 Ouagadougou, Burkina Faso
| | - Halidou Tinto
- grid.457337.10000 0004 0564 0509Institut de Recherche en Science de la Santé - Unité de Recherche Clinique de Nanoro (IRSS-URCN), Ouagadougou, Burkina Faso
| | - Afizi Kibuuka
- grid.463352.50000 0004 8340 3103Infectious Diseases Research Collaboration (IDRC), Kampala, Uganda
| | - Diolinda Nahum
- Centre de Recherches Entomologique de Cotonou (CREC), Cotonou, Benin
| | - Denise Patricia Mawili-Mboumba
- grid.502965.dDépartement de Parasitologie-Mycologie-Médecine Tropicale, Faculté de Médecine – Université des Sciences de la Santé, Libreville, Gabon
| | - Rella Zoleko-Manego
- grid.452268.fCentre de Recherches Médicales de Lambaréné (CERMEL), Lambaréné, Gabon ,Department of Tropical Medicine, Bernhard Nocht Institute for Tropical Medicine, and University Medical Center Hamburg-Eppendorf, Hamburg, Germany ,grid.10392.390000 0001 2190 1447Institute for Tropical Medicine, University of Tübingen, Tübingen, Germany
| | - Irene Mugenya
- grid.33058.3d0000 0001 0155 5938Kenya Medical Research Institute-Centre for Respiratory Diseases Research (KEMRI-CRDR), Nairobi, Kenya
| | - Frederick Olewe
- grid.33058.3d0000 0001 0155 5938Centre for Clinical Research, Kenya Medical Research Institute, Kisumu, Kenya ,grid.442494.b0000 0000 9430 1509Centre for Research in Therapeutic Sciences (CREATES), Strathmore University, Nairobi, Kenya
| | - Stephan Duparc
- grid.452605.00000 0004 0432 5267Medicines for Malaria Venture, Geneva, Switzerland
| | - Bernhards Ogutu
- grid.33058.3d0000 0001 0155 5938Centre for Clinical Research, Kenya Medical Research Institute, Kisumu, Kenya ,grid.442494.b0000 0000 9430 1509Centre for Research in Therapeutic Sciences (CREATES), Strathmore University, Nairobi, Kenya
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Chalon S, Chughlay MF, Abla N, Marie Tchouatieu A, Haouala A, Hutter B, Lorch U, Macintyre F. Unanticipated CNS Safety Signal in a Placebo-Controlled, Randomized Trial of Co-Administered Atovaquone-Proguanil and Amodiaquine. Clin Pharmacol Ther 2021; 111:867-877. [PMID: 34453327 PMCID: PMC9291514 DOI: 10.1002/cpt.2404] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2021] [Accepted: 07/29/2021] [Indexed: 01/28/2023]
Abstract
Atovaquone‐proguanil (ATV‐PG) plus amodiaquine (AQ) has been considered as a potential replacement for sulfadoxine‐pyrimethamine plus AQ for seasonal malaria chemoprevention in African children. This randomized, double‐blind, placebo‐controlled, parallel group study assessed the safety, tolerability, and pharmacokinetics (PKs) of ATV‐PG plus AQ in healthy adult males and females of Black sub‐Saharan African origin. Participants were randomized to four treatment groups: ATV‐PG/AQ (n = 8), ATV‐PG/placebo (n = 12), AQ/placebo (n = 12), and placebo/placebo (n = 12). Treatments were administered orally once daily for 3 days (days 1–3) at daily doses of ATV‐PQ 1000/400 mg and AQ 612 mg. Co‐administration of ATV‐PG/AQ had no clinically relevant effect on PK parameters for ATV, PG, the PG metabolite cycloguanil, AQ, or the AQ metabolite N‐desethyl‐amodiaquine. Adverse events occurred in 8 of 8 (100%) of participants receiving ATV‐PG/AQ, 11 of 12 (91.7%) receiving ATV‐PG, 11 of 12 (91.7%) receiving AQ, and 3 of 12 (25%) receiving placebo. The safety and tolerability profiles of ATV‐PG and AQ were consistent with previous reports. In the ATV‐PG/AQ group, 2 of 8 participants experienced extrapyramidal adverse effects (EPAEs) on day 3, both psychiatric and physical, which appeared unrelated to drug plasma PKs or cytochrome P450 2C8 phenotype. Although rare cases are reported with AQ administration, the high incidence of EPAE was unexpected in this small study. Owing to the unanticipated increased frequency of EPAE observed, the combination of ATV‐PQ plus AQ is not recommended for further evaluation in prophylaxis of malaria in African children.
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Affiliation(s)
| | | | - Nada Abla
- Medicines for Malaria Venture, Geneva, Switzerland
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Leroy D, Macintyre F, Adoke Y, Ouoba S, Barry A, Mombo-Ngoma G, Ndong Ngomo JM, Varo R, Dossou Y, Tshefu AK, Duong TT, Phuc BQ, Laurijssens B, Klopper R, Khim N, Legrand E, Ménard D. African isolates show a high proportion of multiple copies of the Plasmodium falciparum plasmepsin-2 gene, a piperaquine resistance marker. Malar J 2019; 18:126. [PMID: 30967148 PMCID: PMC6457011 DOI: 10.1186/s12936-019-2756-4] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2018] [Accepted: 03/29/2019] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Today, the development of new and well-tolerated anti-malarial drugs is strongly justified by the emergence of Plasmodium falciparum resistance. In 2014-2015, a phase 2b clinical study was conducted to evaluate the efficacy of a single oral dose of Artefenomel (OZ439)-piperaquine (PPQ) in Asian and African patients presenting with uncomplicated falciparum malaria. METHODS Blood samples collected before treatment offered the opportunity to investigate the proportion of multidrug resistant parasite genotypes, including P. falciparum kelch13 mutations and copy number variation of both P. falciparum plasmepsin 2 (Pfpm2) and P. falciparum multidrug resistance 1 (Pfmdr1) genes. RESULTS Validated kelch13 resistance mutations including C580Y, I543T, P553L and V568G were only detected in parasites from Vietnamese patients. In Africa, isolates with multiple copies of the Pfmdr1 gene were shown to be more frequent than previously reported (21.1%, range from 12.4% in Burkina Faso to 27.4% in Uganda). More strikingly, high proportions of isolates with multiple copies of the Pfpm2 gene, associated with piperaquine (PPQ) resistance, were frequently observed in the African sites, especially in Burkina Faso and Uganda (> 30%). CONCLUSIONS These findings were considered to sharply contrast with the recent description of increased sensitivity to PPQ of Ugandan parasite isolates. This emphasizes the necessity to investigate in vitro susceptibility profiles to PPQ of African isolates with multiple copies of the Pfpm2 gene and estimate the risk of development of PPQ resistance in Africa. Trial registration Clinicaltrials.gov reference: NCT02083380. Study title: Phase II efficacy study of artefenomel and piperaquine in adults and children with P. falciparum malaria. https://clinicaltrials.gov/ct2/results?cond=&term=NCT02083380&cntry=&state=&city=&dist= . FSFV: 23-Jul-2014; LSLV: 09-Oct-2015.
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Affiliation(s)
- Didier Leroy
- Medicines for Malaria Venture, Geneva, Switzerland.
| | | | - Yeka Adoke
- Infectious Diseases Research Collaboration, Tororo Hospital, Tororo, Uganda
| | - Serge Ouoba
- Institut de Recherche en Sciences de la Santé - Unité de Recherche Clinique de Nanoro, Ouagadougou, Burkina Faso
| | - Aissata Barry
- Institut de Recherche en Sciences de la Santé - Unité de Recherche Clinique de Nanoro, Ouagadougou, Burkina Faso
| | - Ghyslain Mombo-Ngoma
- Centre de Recherches Médicales de Lambaréné, Lambaréné, Gabon
- Institut für Tropenmedizin, Universität Tübingen, Tübingen, Germany
| | | | - Rosauro Varo
- ISGlobal, Barcelona Ctr. Int. Health Res. (CRESIB), Hospital Clínic - Universitat de Barcelona, Barcelona, Spain
- Centro de Investigação em Saúde de Manhiça (CISM), Maputo, Mozambique
- ICREA, Pg. Lluís Companys 23, 08010, Barcelona, Spain
| | - Yannelle Dossou
- Centre de Recherche sur le Paludisme Associé à la Grossesse et l'Enfance, Faculté Des Sciences De La Santé, Cotonou, Benin
| | - Antoinette Kitoto Tshefu
- Centre de Recherche du Centre Hospitalier de Mont Amba, Kinshasa School of Public Health, University of Kinshasa, Kinshasa, Democratic Republic of the Congo
| | - Tran Thanh Duong
- National Institute of Malariology, Parasitology and Entomology, Hanoi, Vietnam
| | - Bui Quang Phuc
- Clinical Pharmaceutical Research Department, National Institute of Malariology, Parasitology and Entomology, 35 Trung Van Street, Nam Tu Liem District, Hanoi, Vietnam
| | | | | | - Nimol Khim
- Malaria Molecular Epidemiology Unit, Institut Pasteur in Cambodia, Phnom Penh, Cambodia
| | - Eric Legrand
- Malaria Genetics and Resistance Group, INSERM U1201-CNRS ERL919, Institut Pasteur, Paris, France
| | - Didier Ménard
- Malaria Genetics and Resistance Group, INSERM U1201-CNRS ERL919, Institut Pasteur, Paris, France.
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Burrows J, Slater H, Macintyre F, Rees S, Thomas A, Okumu F, Hooft van Huijsduijnen R, Duparc S, Wells TNC. A discovery and development roadmap for new endectocidal transmission-blocking agents in malaria. Malar J 2018; 17:462. [PMID: 30526594 PMCID: PMC6287360 DOI: 10.1186/s12936-018-2598-5] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2018] [Accepted: 11/24/2018] [Indexed: 11/10/2022] Open
Abstract
Reaching the overall goal of eliminating malaria requires halting disease transmission. One approach to blocking transmission is to prevent passage of the parasite to a mosquito, by preventing formation or transmission of gametocytes. An alternative approach, pioneered in the veterinary field, is to use endectocides, which are molecules that render vertebrate blood meals toxic for the mosquito vector, also killing the parasite. Field studies and modelling suggest that reducing the lifespan of the mosquito may significantly reduce transmission, given the lengthy maturation process of the parasite. To guide the development of new endectocides, or the reformulation of existing molecules, it is important to construct a framework of the required attributes, commonly called the target candidate profile. Here, using a combination of insights from current endectocides, mathematical models of the malaria transmission dynamics, and known impacts of vector control, a target candidate profile (TCP-6) and a regulatory strategy are proposed for a transmission reducing agent. The parameters chosen can be used to assess the potential of a new medicine, independent of whether it has classical endectocide activity, reduces the insect and parasite lifespan or any combination of all three, thereby constituting an ‘endectocidal transmission blocking’ paradigm.
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Affiliation(s)
- Jeremy Burrows
- Medicines for Malaria Venture, Route de Pré Bois 20, 1215, Geneva 15, Switzerland.
| | - Hannah Slater
- PATH, 2201 Westlake Avenue, Seattle, WA, 98121, USA.,Department of Infectious Disease Epidemiology, MRC Centre for Global Disease Analysis, Imperial College London, Norfolk Place, London, W2 1PG, UK
| | - Fiona Macintyre
- Medicines for Malaria Venture, Route de Pré Bois 20, 1215, Geneva 15, Switzerland
| | - Sarah Rees
- Innovative Vector Control Consortium, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, L3 5QA, UK
| | - Anna Thomas
- Medicines for Malaria Venture, Route de Pré Bois 20, 1215, Geneva 15, Switzerland
| | - Fredros Okumu
- Environmental Health and Ecological Sciences Department, Ifakara Health Institute, Off Mlabani Passage, Ifakara, Morogoro, United Republic of Tanzania.,School of Public Health, Faculty of Health Sciences, University of the Witwatersrand, Parktown, Republic of South Africa.,Institute of Biodiversity, Animal Health and Comparative Medicine, University of Glasgow, Glasgow, UK
| | | | - Stephan Duparc
- Medicines for Malaria Venture, Route de Pré Bois 20, 1215, Geneva 15, Switzerland
| | - Timothy N C Wells
- Medicines for Malaria Venture, Route de Pré Bois 20, 1215, Geneva 15, Switzerland
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5
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Macintyre F, Ramachandruni H, Burrows JN, Holm R, Thomas A, Möhrle JJ, Duparc S, Hooft van Huijsduijnen R, Greenwood B, Gutteridge WE, Wells TNC, Kaszubska W. Injectable anti-malarials revisited: discovery and development of new agents to protect against malaria. Malar J 2018; 17:402. [PMID: 30384848 PMCID: PMC6211409 DOI: 10.1186/s12936-018-2549-1] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2018] [Accepted: 10/24/2018] [Indexed: 12/20/2022] Open
Abstract
Over the last 15 years, the majority of malaria drug discovery and development efforts have focused on new molecules and regimens to treat patients with uncomplicated or severe disease. In addition, a number of new molecular scaffolds have been discovered which block the replication of the parasite in the liver, offering the possibility of new tools for oral prophylaxis or chemoprotection, potentially with once-weekly dosing. However, an intervention which requires less frequent administration than this would be a key tool for the control and elimination of malaria. Recent progress in HIV drug discovery has shown that small molecules can be formulated for injections as native molecules or pro-drugs which provide protection for at least 2 months. Advances in antibody engineering offer an alternative approach whereby a single injection could potentially provide protection for several months. Building on earlier profiles for uncomplicated and severe malaria, a target product profile is proposed here for an injectable medicine providing long-term protection from this disease. As with all of such profiles, factors such as efficacy, cost, safety and tolerability are key, but with the changing disease landscape in Africa, new clinical and regulatory approaches are required to develop prophylactic/chemoprotective medicines. An overall framework for these approaches is suggested here.
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Affiliation(s)
- Fiona Macintyre
- Medicines for Malaria Venture, Route de Pré Bois 20, 1215, Geneva, Switzerland
| | - Hanu Ramachandruni
- Medicines for Malaria Venture, Route de Pré Bois 20, 1215, Geneva, Switzerland
| | - Jeremy N Burrows
- Medicines for Malaria Venture, Route de Pré Bois 20, 1215, Geneva, Switzerland
| | - René Holm
- Drug Product Development, Janssen R&D, Johnson & Johnson, Turnhoutseweg 30, 2340, Beerse, Belgium.,Department of Science and Environment, Roskilde University, 4000, Roskilde, Denmark
| | - Anna Thomas
- Medicines for Malaria Venture, Route de Pré Bois 20, 1215, Geneva, Switzerland
| | - Jörg J Möhrle
- Medicines for Malaria Venture, Route de Pré Bois 20, 1215, Geneva, Switzerland
| | - Stephan Duparc
- Medicines for Malaria Venture, Route de Pré Bois 20, 1215, Geneva, Switzerland
| | | | - Brian Greenwood
- Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, UK
| | | | - Timothy N C Wells
- Medicines for Malaria Venture, Route de Pré Bois 20, 1215, Geneva, Switzerland.
| | - Wiweka Kaszubska
- Medicines for Malaria Venture, Route de Pré Bois 20, 1215, Geneva, Switzerland
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Macintyre F, Adoke Y, Tiono AB, Duong TT, Mombo-Ngoma G, Bouyou-Akotet M, Tinto H, Bassat Q, Issifou S, Adamy M, Demarest H, Duparc S, Leroy D, Laurijssens BE, Biguenet S, Kibuuka A, Tshefu AK, Smith M, Foster C, Leipoldt I, Kremsner PG, Phuc BQ, Ouedraogo A, Ramharter M. A randomised, double-blind clinical phase II trial of the efficacy, safety, tolerability and pharmacokinetics of a single dose combination treatment with artefenomel and piperaquine in adults and children with uncomplicated Plasmodium falciparum malaria. BMC Med 2017; 15:181. [PMID: 28988541 PMCID: PMC5632828 DOI: 10.1186/s12916-017-0940-3] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/01/2017] [Accepted: 09/05/2017] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The clinical development of a single encounter treatment for uncomplicated malaria has the potential to significantly improve the effectiveness of antimalarials. Exploratory data suggested that the combination of artefenomel and piperaquine phosphate (PQP) has the potential to achieve satisfactory cure rates as a single dose therapy. The primary objective of the study was to determine whether a single dose of artefenomel (800 mg) plus PQP in ascending doses is an efficacious treatment for uncomplicated Plasmodium falciparum malaria in the 'target' population of children ≤ 5 years of age in Africa as well as Asian patients of all ages. METHODS Patients in six African countries and in Vietnam were randomised to treatment with follow-up for 42-63 days. Efficacy, tolerability, safety and pharmacokinetics were assessed. Additional key objectives were to characterise the exposure-response relationship for polymerase chain reaction (PCR)-adjusted adequate clinical and parasitological response at day 28 post-dose (ACPR28) and to further investigate Kelch13 mutations. Patients in Africa (n = 355) and Vietnam (n = 82) were included, with 85% of the total population being children < 5 years of age. RESULTS ACPR28 in the per protocol population (95% confidence interval) was 70.8% (61.13-79.19), 68.4% (59.13-76.66) and 78.6% (70.09-85.67) for doses of 800 mg artefenomel with 640 mg, 960 mg and 1440 mg of PQP respectively. ACPR28 was lower in Vietnamese than in African patients (66.2%; 54.55-76.62 and 74.5%; 68.81-79.68) respectively. Within the African population, efficacy was lowest in the youngest age group of ≥ 0.5 to ≤ 2 years, 52.7% (38.80-66.35). Initial parasite clearance was twice as long in Vietnam than in Africa. Within Vietnam, the frequency of the Kelch13 mutation was 70.1% and was clearly associated with parasite clearance half-life (PCt1/2). The most significant tolerability finding was vomiting (28.8%). CONCLUSIONS In this first clinical trial evaluating a single encounter antimalarial therapy, none of the treatment arms reached the target efficacy of > 95% PCR-adjusted ACPR at day 28. Achieving very high efficacy following single dose treatment is challenging, since > 95% of the population must have sufficient concentrations to achieve cure across a range of parasite sensitivities and baseline parasitaemia levels. While challenging, the development of tools suitable for deployment as single encounter curative treatments for adults and children in Africa and to support elimination strategies remains a key development goal. TRIAL REGISTRATION ClinicalTrials.gov, NCT02083380 . Registered on 7 March 2014.
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Affiliation(s)
| | - Yeka Adoke
- Infectious Diseases Research Collaboration, Tororo Hospital, Tororo, Uganda
| | - Alfred B Tiono
- Centre National de Recherche et de Formation sur le Paludisme, Ouagadougou, Burkina Faso
| | - Tran Thanh Duong
- National Institute of Malariology, Parasitology and Entomology, Hanoi, Vietnam
| | - Ghyslain Mombo-Ngoma
- Centre de Recherches Médicales de Lambaréné, Lambaréné, Gabon.,Institut für Tropenmedizin, Universität Tübingen, Tübingen, Germany.,Universite des Sciences de la Sante Gabon, Département de Parasitology, Malaria Clinical and Operational Research Unit, Melen Hospital, Libreville, Gabon
| | - Marielle Bouyou-Akotet
- Universite des Sciences de la Sante Gabon, Département de Parasitology, Malaria Clinical and Operational Research Unit, Melen Hospital, Libreville, Gabon
| | - Halidou Tinto
- Institut de Recherche en Sciences de la Santé - Unité de Recherche Clinique de Nanoro, Ouagadougou, Burkina Faso
| | - Quique Bassat
- ISGlobal, Barcelona Ctr. Int. Health Res. (CRESIB), Hospital Clínic - Universitat de Barcelona, Barcelona, Spain.,Centro de Investigação em Saúde de Manhiça (CISM), Maputo, Mozambique.,ICREA, Pg. Lluís Companys 23, 08010, Barcelona, Spain.,Pediatric Infectious Diseases Unit, Pediatrics Department, Hospital Sant Joan de Déu (University of Barcelona), Barcelona, Spain.,Universidad Europea de Madrid, Madrid, Spain
| | - Saadou Issifou
- Centre de Recherche sur le Paludisme Associé à la Grossesse et l'Enfance, Faculte Des Sciences De La Sante, Cotonou, Benin
| | - Marc Adamy
- Medicines for Malaria Venture, Geneva, Switzerland
| | | | | | - Didier Leroy
- Medicines for Malaria Venture, Geneva, Switzerland
| | | | | | - Afizi Kibuuka
- Infectious Diseases Research Collaboration, Tororo Hospital, Tororo, Uganda
| | - Antoinette Kitoto Tshefu
- Centre de Recherche du Centre Hospitalier de Mont Amba, Kinshasa School of Public Health, University of Kinshasa, Kinshasa, Democratic Republic of the Congo
| | - Melnick Smith
- QuintilesIMS, Department: Biostatistics, Bloemfontein, South Africa
| | - Chanelle Foster
- QuintilesIMS, Department: Biostatistics, Bloemfontein, South Africa
| | - Illse Leipoldt
- QuintilesIMS, Department: Biostatistics, Bloemfontein, South Africa
| | - Peter G Kremsner
- Centre de Recherches Médicales de Lambaréné, Lambaréné, Gabon.,Institut für Tropenmedizin, Universität Tübingen, Tübingen, Germany
| | - Bui Quang Phuc
- National Institute of Malariology, Parasitology and Entomology, Hanoi, Vietnam
| | - Alphonse Ouedraogo
- Centre National de Recherche et de Formation sur le Paludisme, Ouagadougou, Burkina Faso
| | - Michael Ramharter
- Centre de Recherches Médicales de Lambaréné, Lambaréné, Gabon. .,Institut für Tropenmedizin, Universität Tübingen, Tübingen, Germany. .,Department of Medicine I, Division of Infectious Diseases, Medical University of Vienna, Vienna, Austria. .,Bernhard Nocht Hospital for Tropical Diseases, Bernhard Nocht Institute for Tropical Medicine and University Medical Center Hamburg-Eppendorf, Hamburg, Germany.
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Burrows JN, Duparc S, Gutteridge WE, van Huijsduijnen RH, Kaszubska W, Macintyre F, Mazzuri S, Möhrle JJ, Wells TNC. Erratum to: New developments in anti-malarial target candidate and product profiles. Malar J 2017; 16:151. [PMID: 28420400 PMCID: PMC5395931 DOI: 10.1186/s12936-017-1809-9] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/02/2022] Open
Affiliation(s)
- Jeremy N Burrows
- Medicines for Malaria Venture, Route de Pré Bois 20, 1215, Geneva 15, Switzerland
| | - Stephan Duparc
- Medicines for Malaria Venture, Route de Pré Bois 20, 1215, Geneva 15, Switzerland
| | | | | | - Wiweka Kaszubska
- Medicines for Malaria Venture, Route de Pré Bois 20, 1215, Geneva 15, Switzerland
| | - Fiona Macintyre
- Medicines for Malaria Venture, Route de Pré Bois 20, 1215, Geneva 15, Switzerland
| | | | - Jörg J Möhrle
- Medicines for Malaria Venture, Route de Pré Bois 20, 1215, Geneva 15, Switzerland
| | - Timothy N C Wells
- Medicines for Malaria Venture, Route de Pré Bois 20, 1215, Geneva 15, Switzerland.
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Burrows JN, Duparc S, Gutteridge WE, Hooft van Huijsduijnen R, Kaszubska W, Macintyre F, Mazzuri S, Möhrle JJ, Wells TNC. New developments in anti-malarial target candidate and product profiles. Malar J 2017; 16:26. [PMID: 28086874 PMCID: PMC5237200 DOI: 10.1186/s12936-016-1675-x] [Citation(s) in RCA: 297] [Impact Index Per Article: 42.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2016] [Accepted: 12/30/2016] [Indexed: 11/10/2022] Open
Abstract
A decade of discovery and development of new anti-malarial medicines has led to a renewed focus on malaria elimination and eradication. Changes in the way new anti-malarial drugs are discovered and developed have led to a dramatic increase in the number and diversity of new molecules presently in pre-clinical and early clinical development. The twin challenges faced can be summarized by multi-drug resistant malaria from the Greater Mekong Sub-region, and the need to provide simplified medicines. This review lists changes in anti-malarial target candidate and target product profiles over the last 4 years. As well as new medicines to treat disease and prevent transmission, there has been increased focus on the longer term goal of finding new medicines for chemoprotection, potentially with long-acting molecules, or parenteral formulations. Other gaps in the malaria armamentarium, such as drugs to treat severe malaria and endectocides (that kill mosquitoes which feed on people who have taken the drug), are defined here. Ultimately the elimination of malaria requires medicines that are safe and well-tolerated to be used in vulnerable populations: in pregnancy, especially the first trimester, and in those suffering from malnutrition or co-infection with other pathogens. These updates reflect the maturing of an understanding of the key challenges in producing the next generation of medicines to control, eliminate and ultimately eradicate malaria.
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Affiliation(s)
- Jeremy N Burrows
- Medicines for Malaria Venture, Route de Pré Bois 20, 1215, Geneva 15, Switzerland
| | - Stephan Duparc
- Medicines for Malaria Venture, Route de Pré Bois 20, 1215, Geneva 15, Switzerland
| | | | | | - Wiweka Kaszubska
- Medicines for Malaria Venture, Route de Pré Bois 20, 1215, Geneva 15, Switzerland
| | - Fiona Macintyre
- Medicines for Malaria Venture, Route de Pré Bois 20, 1215, Geneva 15, Switzerland
| | | | - Jörg J Möhrle
- Medicines for Malaria Venture, Route de Pré Bois 20, 1215, Geneva 15, Switzerland
| | - Timothy N C Wells
- Medicines for Malaria Venture, Route de Pré Bois 20, 1215, Geneva 15, Switzerland.
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Phyo AP, Jittamala P, Nosten FH, Pukrittayakamee S, Imwong M, White NJ, Duparc S, Macintyre F, Baker M, Möhrle JJ. Antimalarial activity of artefenomel (OZ439), a novel synthetic antimalarial endoperoxide, in patients with Plasmodium falciparum and Plasmodium vivax malaria: an open-label phase 2 trial. Lancet Infect Dis 2015; 16:61-69. [PMID: 26448141 PMCID: PMC4700386 DOI: 10.1016/s1473-3099(15)00320-5] [Citation(s) in RCA: 125] [Impact Index Per Article: 13.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/26/2015] [Revised: 08/31/2015] [Accepted: 09/03/2015] [Indexed: 11/28/2022]
Abstract
Background Artefenomel (OZ439) is a novel synthetic trioxolane with improved pharmacokinetic properties compared with other antimalarial drugs with the artemisinin pharmacophore. Artefenomel has been generally well tolerated in volunteers at doses up to 1600 mg and is being developed as a partner drug in an antimalarial combination treatment. We investigated the efficacy, tolerability, and pharmacokinetics of artefenomel at different doses in patients with Plasmodium falciparum or Plasmodium vivax malaria. Methods This phase 2a exploratory, open-label trial was done at the Hospital for Tropical Diseases, Bangkok, and the Shoklo Malaria Research Unit in Thailand. Adult patients with acute, uncomplicated P falciparum or P vivax malaria received artefenomel in a single oral dose (200 mg, 400 mg, 800 mg, or 1200 mg). The first cohort received 800 mg. Testing of a new dose of artefenomel in a patient cohort was decided on after safety and efficacy assessment of the preceding cohort. The primary endpoint was the natural log parasite reduction per 24 h. Definitive oral treatment was given at 36 h. This trial is registered with ClinicalTrials.gov, number NCT01213966. Findings Between Oct 24, 2010, and May 25, 2012, 82 patients were enrolled (20 in each of the 200 mg, 400 mg, and 800 mg cohorts, and 21 in the 1200 mg cohort). One patient withdrew consent (before the administration of artefenomel) but there were no further dropouts. The parasite reduction rates per 24 h ranged from 0·90 to 1·88 for P falciparum, and 2·09 to 2·53 for P vivax. All doses were equally effective in both P falciparum and P vivax malaria, with median parasite clearance half-lives of 4·1 h (range 1·3–6·7) to 5·6 h (2·0–8·5) for P falciparum and 2·3 h (1·2–3·9) to 3·2 h (0·9–15·0) for P vivax. Maximum plasma concentrations, dose-proportional to 800 mg, occurred at 4 h (median). The estimated elimination half-life was 46–62 h. No serious drug-related adverse effects were reported; other adverse effects were generally mild and reversible, with the highest number in the 1200 mg cohort (17 [81%] patients with at least one adverse event). The most frequently reported adverse effect was an asymptomatic increase in plasma creatine phosphokinase concentration (200 mg, n=5; 400 mg, n=3; 800 mg, n=1; 1200 mg, n=3). Interpretation Artefenomel is a new synthetic antimalarial peroxide with a good safety profile that clears parasitaemia rapidly in both P falciparum and P vivax malaria. Its long half-life suggests a possible use in a single-dose treatment in combination with other drugs. Funding Bill & Melinda Gates Foundation, Wellcome Trust, and UK Department for International Development.
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Affiliation(s)
- Aung Pyae Phyo
- Shoklo Malaria Research Unit, Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Mae Sot, Thailand; Mahidol-Oxford Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand; Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Podjanee Jittamala
- Department of Tropical Hygiene, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - François H Nosten
- Shoklo Malaria Research Unit, Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Mae Sot, Thailand; Mahidol-Oxford Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand; Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Sasithon Pukrittayakamee
- Department of Clinical Tropical Medicine, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Mallika Imwong
- Department of Molecular Tropical Medicine and Genetics, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Nicholas J White
- Mahidol-Oxford Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand; Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | | | | | - Mark Baker
- Medicines for Malaria Venture, Geneva, Switzerland
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Darpo B, Ferber G, Siegl P, Laurijssens B, Macintyre F, Toovey S, Duparc S. Evaluation of the QT effect of a combination of piperaquine and a novel anti-malarial drug candidate OZ439, for the treatment of uncomplicated malaria. Br J Clin Pharmacol 2015; 80:706-15. [PMID: 25966781 PMCID: PMC4594707 DOI: 10.1111/bcp.12680] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2015] [Revised: 05/09/2015] [Accepted: 05/11/2015] [Indexed: 02/02/2023] Open
Abstract
AIMS The aim was to investigate the QT effect of a single dose combination regimen of piperaquine phosphate (PQP) and a novel aromatic trioxolane, OZ439, for malaria treatment. METHODS Exposure-response (ER) analysis was performed on data from a placebo-controlled, single dose, study with OZ439 and PQP. Fifty-nine healthy subjects aged 18 to 55 years received OZ439 alone or placebo in a first period, followed by OZ439 plus PQP or matching placebos in period 2. OZ439 and PQP doses ranged from 100-800 mg and 160-1440 mg, respectively. Twelve-lead ECG tracings and PK samples were collected serially pre- and post-dosing. RESULTS A significant relation between plasma concentrations and placebo-corrected change from baseline QTc F (ΔΔQTc F) was demonstrated for piperaquine, but not for OZ439, with a mean slope of 0.047 ms per ng ml(-1) (90% CI 0.038, 0.057). Using an ER model that accounts for plasma concentrations of both piperaquine and OZ439, a largest mean QTc F effect of 14 ms (90% CI 10, 18 ms) and 18 ms (90% CI 14, 22 ms) was predicted at expected plasma concentrations of a single dose 800 mg OZ439 combined with PQP 960 mg (188 ng ml(-1) ) and 1440 mg (281 ng ml(-1) ), respectively, administered in the fasted state. CONCLUSIONS Piperaquine prolongs the QTc interval in a concentration-dependent way. A single dose regimen combining 800 mg OZ439 with 960 mg or 1440 mg PQP is expected to result in lower peak piperaquine plasma concentrations compared with available 3 day PQP-artemisinin combinations and can therefore be predicted to cause less QTc prolongation.
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Affiliation(s)
- Borje Darpo
- Associate Professor of Cardiology, Karolinska Institute, Division of Cardiovascular Medicine, Department of Clinical Sciences, Danderyd's Hospital, Stockholm, Sweden
| | - Georg Ferber
- Georg Ferber Statistical Consultant, Riehen, Switzerland
| | - Peter Siegl
- Siegl Pharma Consulting LLC, Blue Bell, Pennsylvania, USA
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Corrigan FM, Van Rhijn AG, Macintyre F, Skinner ER, Horrobin DF. Dietary Supplementation with Zinc Sulphate, Sodium Selenite and Fatty Acids in Early Dementia of Alzheimer's Type. II: Effects on Lipids. ACTA ACUST UNITED AC 2009. [DOI: 10.3109/13590849109084124] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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Mantell SJ, Stephenson PT, Monaghan SM, Maw GN, Trevethick MA, Yeadon M, Walker DK, Selby MD, Batchelor DV, Rozze S, Chavaroche H, Lemaitre A, Wright KN, Whitlock L, Stuart EF, Wright PA, Macintyre F. SAR of a series of inhaled A(2A) agonists and comparison of inhaled pharmacokinetics in a preclinical model with clinical pharmacokinetic data. Bioorg Med Chem Lett 2009; 19:4471-5. [PMID: 19501510 DOI: 10.1016/j.bmcl.2009.05.027] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2009] [Revised: 05/07/2009] [Accepted: 05/08/2009] [Indexed: 10/20/2022]
Abstract
COPD is a major cause of mortality in the western world. A(2A) agonists are postulated to reduce the lung inflammation that causes COPD. The cardiovascular effects of A(2A) agonists dictate that a compound needs to be delivered by inhalation to be therapeutically useful. The pharmacological and pharmacokinetic SAR of a series of inhaled A(2A) agonists is described leading through to human pharmacokinetic data for a clinical candidate.
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Affiliation(s)
- Simon J Mantell
- Pfizer Global Research and Development, Sandwich Laboratories, Ramsgate Road, Kent, CT13 9NJ, United Kingdom.
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Macintyre F, Besenius P, Sherrington DC. Synthesis of Polymer Microspheres via Self-Assembly of Monodisperse Precursor Particles. Ind Eng Chem Res 2007. [DOI: 10.1021/ie0608354] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Marshall S, Macintyre F, James I, Krams M, Jonsson NE. Role of mechanistically-based pharmacokinetic/pharmacodynamic models in drug development : a case study of a therapeutic protein. Clin Pharmacokinet 2006; 45:177-97. [PMID: 16485916 DOI: 10.2165/00003088-200645020-00004] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
BACKGROUND AND OBJECTIVE This case study describes the pharmacokinetic and pharmacodynamic modelling undertaken during the development programme for UK-279,276 (neutrophil inhibitory factor), focusing on the transition from early empirical-based models to a final mechanistic-based model. UK-279,276 binds to the CD11b/CD18 (MAC-1) on neutrophils and was under development for the treatment of ischaemic stroke. METHODS The aims, data, models, results and value-to-drug development process across four stages of model development are described: (i) the validation of the pharmacokinetic assay; (ii) the development and application of an empirical patient pharmacokinetic/pharmacodynamic model; (iii) the development of a mechanistic-based model to bridge between patients and healthy volunteers; and (iv) propagation of the stage III model to a large efficacy study. The analyses utilised available concentration measurements (stages I-IV), CD11b receptor occupancy data (stages I-III) and neutrophil count data (stages III-IV) from three healthy volunteers (study 1, n=51; study 2, n=31; study 4, n=15) and two patient studies (study 3, n=169; study 5, n=992). In studies 1-4, subjects received placebo or between three and six doses of UK-279,276 covering a range of 0.006 and 1.5 mg/kg as a single 15-minute intravenous infusion. In study 5, subjects received placebo or one of 15 possible doses of UK-279,276 (10--20mg) assigned through adaptive design and administered as a single 15-minute intravenous infusion. All model building was conducted using NONMEM version VI (beta). The empirical pharmacokinetic/pharmacodynamic model developed during stage I was used to demonstrate that the pharmacokinetic assay was measuring biologically active drug. Simulations from the stage II model, developed from study 3, were used in the design of study 5. The model supported the switch to a fixed-dose regimen and the selection of the maximum dose and dosage increments. The common mechanistic-based model developed during stage III was used to support the 'comparability strategy' for UK-279,276 and provided insight into the underlying clearance mechanisms. At stage 4, the prior functionality available with NONMEM was used to successfully propagate the model from stage III in order to analyse the pharmacokinetic data from study 5. The analysis indicated that the exposure in study 5 was consistent with prior data. The role of empirical-based models in providing the learning for future mechanistic model development was highlighted. Similarly, the qualitative and quantitative aspects to knowledge propagation and the ultimate benefits from the development of the mechanistic-based model were demonstrated. While the empirical-based models were used to guide some early drug development decisions for UK-279,276, the development of the mechanistic-based model was valuable in linking the complex pharmacokinetics/pharmacodynamics of UK-279,276 across the phases of drug development.
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Affiliation(s)
- Scott Marshall
- Department of Clinical Pharmacology, Pfizer Global Research and Development, Sandwich, UK.
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Jonsson EN, Macintyre F, James I, Krams M, Marshall S. Bridging the Pharmacokinetics and Pharmacodynamics of UK-279,276 Across Healthy Volunteers and Stroke Patients Using a Mechanistically Based Model for Target-Mediated Disposition. Pharm Res 2005; 22:1236-46. [PMID: 16078133 DOI: 10.1007/s11095-005-5264-x] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2004] [Accepted: 03/15/2005] [Indexed: 11/26/2022]
Abstract
PURPOSE UK-279,276 is a recombinant glycoprotein and is a selective antagonist of CD11b, which in preclinical models of acute stroke blocks the infiltration of activated neutrophils into the site of infarction. Binding of UK-279,276 to the CD11b receptors is hypothesized to facilitate its elimination. The event of an acute stroke leads to proliferation of neutrophils and an up-regulation of CD11b, which results in different pharmacokinetics/pharmacodynamics (PK/PD) in patients than in healthy volunteers. The aim of this current analysis was to develop a mechanistically based model to bridge the differences between healthy volunteers and patients. METHODS PK samples, neutrophil counts, and total number and number of free CD11b receptors per neutrophils from three healthy volunteer studies (n=98) and one patient study (n=169) were modeled using the mixed effects modeling software NONMEM version VI (beta). Three mechanistic submodels were developed based on underlying physiology and pharmacology: (1) neutrophil maturation and proliferation, (2) CD11b up-regulation, and (3) three clearance pathways for UK-279-276 including CD11b-mediated elimination. RESULTS The model accurately described the time course of CD11b expression, CD11b binding, and the measured PK of UK-279,276 and accounted for the PK/PD differences between healthy volunteers and patients. CONCLUSIONS A complex mechanistic model that closely resembled the "true" underlying system provided an effective bridge between healthy volunteers and patients by appropriately accounting for the underlying disease-dependent target mediated disposition.
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Affiliation(s)
- E Niclas Jonsson
- Division of Pharmacokinetics & Drug Therapy, Department of Pharmaceutical Biosciences, Uppsala University, Box 591, SE-751 24, Uppsala, Sweden.
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Van Rhijn A, Macintyre F, Corrigan FM, Watt C, Ijomah G, Skinner ER. Plasma lipoprotein profiles and the distribution of high-density lipoprotein subfractions in the elderly: the effect of Alzheimer's disease and multi-infarct dementia. Biochem Soc Trans 1990; 18:324. [PMID: 2379739 DOI: 10.1042/bst0180324] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
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Cunningham C, Gavin MP, Whiting PH, Burke MD, Macintyre F, Thomson AW, Simpson JG. Serum cyclosporin levels, hepatic drug metabolism and renal tubulotoxicity. Biochem Pharmacol 1984; 33:2857-61. [PMID: 6477645 DOI: 10.1016/0006-2952(84)90207-7] [Citation(s) in RCA: 49] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
The present study was designed to examine inter-relationships between serum cyclosporin (CsA) levels, hepatic drug metabolising enzyme activity and CsA induced nephrotoxicity. CsA (25 mg/kg p.o.) was administered daily to male Sprague-Dawley rats: groups of animals were killed on days 0, 4, 7, 10 and 14 and thereafter at weekly intervals over the 7-week course of the experiment. Nephrotoxicity was evaluated by measuring tubular enzymuria and by light microscopy and serum CsA levels (parent drug plus certain metabolites) were determined by radioimmunoassay. The hepatic microsomal mono-oxygenase enzyme system was monitored by measurement of cytochrome P-450, aminopyrine N-demethylase and NADPH-cytochrome c reductase. Nephrotoxicity appeared within 4 days of starting treatment and continued for 4 weeks. Between weeks 4 and 6 there was a period of complete remission followed by the return of renal damage. Aminopyrine N-demethylase activity fell during the first 4 weeks. During the period of remission, however, N-demethylase activity rose to a point significantly higher than pretreatment values and serum CsA levels fell to their lowest concentration. With relapse, hepatic N-demethylase activity again fell below normal and serum drug levels rose to their pre-remission values. From the third week onward, changes in NADPH-cytochrome c reductase activity paralleled those in N-demethylase activity. The hepatic microsomal concentration of cytochrome P-450 did not, however, change significantly during the 7-week period of CsA treatment. Our results suggest that the spontaneous remission of CsA-induced nephrotoxicity is due to a reduction in circulating drug levels caused by increased hepatic CsA metabolism.
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Abstract
When the correct values for the temperature coefficient of carbon dioxide solubility in seawater are used, theoretical calculations show that no measurable carbon-isotope redistribution occurs between sea and air for any plausible change in the sea-surface temperature. Although this fact invalidates one possible paleothermometer, it somewhat simplifies the interpretation of carbon-13 data in terrestrial biological samples.
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