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Clare RH, Clark R, Bardelle C, Harper P, Collier M, Johnston KL, Plant H, Plant D, McCall E, Slatko BE, Cantin L, Wu B, Ford L, Murray D, Rich K, Wigglesworth M, Taylor MJ, Ward SA. Development of a High-Throughput Cytometric Screen to Identify Anti- Wolbachia Compounds: The Power of Public-Private Partnership. SLAS DISCOVERY 2019; 24:537-547. [PMID: 30958712 PMCID: PMC6537165 DOI: 10.1177/2472555219838341] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
The Anti-Wolbachia (A·WOL) consortium at the Liverpool School of
Tropical Medicine (LSTM) has partnered with the Global High-Throughput Screening
(HTS) Centre at AstraZeneca to create the first anthelmintic HTS for neglected
tropical diseases (NTDs). The A·WOL consortium aims to identify novel
macrofilaricidal drugs targeting the essential bacterial symbiont
(Wolbachia) of the filarial nematodes causing
onchocerciasis and lymphatic filariasis. Working in collaboration, we have
validated a robust high-throughput assay capable of identifying compounds that
selectively kill Wolbachia over the host insect cell. We
describe the development and validation process of this complex, phenotypic
high-throughput assay and provide an overview of the primary outputs from
screening the AstraZeneca library of 1.3 million compounds.
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Jacobs RT, Lunde CS, Freund YR, Hernandez V, Li X, Xia Y, Carter DS, Berry PW, Halladay J, Rock F, Stefanakis R, Easom E, Plattner JJ, Ford L, Johnston KL, Cook DAN, Clare R, Cassidy A, Myhill L, Tyrer H, Gamble J, Guimaraes AF, Steven A, Lenz F, Ehrens A, Frohberger SJ, Koschel M, Hoerauf A, Hübner MP, McNamara CW, Bakowski MA, Turner JD, Taylor MJ, Ward SA. Boron-Pleuromutilins as Anti- Wolbachia Agents with Potential for Treatment of Onchocerciasis and Lymphatic Filariasis. J Med Chem 2019; 62:2521-2540. [PMID: 30730745 PMCID: PMC6421521 DOI: 10.1021/acs.jmedchem.8b01854] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2018] [Indexed: 01/07/2023]
Abstract
A series of pleuromutilins modified by introduction of a boron-containing heterocycle on C(14) of the polycyclic core are described. These analogs were found to be potent anti- Wolbachia antibiotics and, as such, may be useful in the treatment of filarial infections caused by Onchocerca volvulus, resulting in Onchocerciasis or river blindness, or Wuchereria bancrofti and Brugia malayi and related parasitic nematodes resulting in lymphatic filariasis. These two important neglected tropical diseases disproportionately impact patients in the developing world. The lead preclinical candidate compound containing 7-fluoro-6-oxybenzoxaborole (15, AN11251) was shown to have good in vitro anti- Wolbachia activity and physicochemical and pharmacokinetic properties providing high exposure in plasma. The lead was effective in reducing the Wolbachia load in filarial worms following oral administration to mice.
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Birgersson S, Valea I, Tinto H, Traore-Coulibaly M, Toe LC, Hoglund RM, Van Geertruyden JP, Ward SA, D’Alessandro U, Abelö A, Tarning J. Population pharmacokinetics of artesunate and dihydroartemisinin in pregnant and non-pregnant women with uncomplicated Plasmodium falciparum malaria in Burkina Faso: an open label trial. Wellcome Open Res 2019; 4:45. [PMID: 32025570 PMCID: PMC6974929 DOI: 10.12688/wellcomeopenres.14849.2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/15/2019] [Indexed: 01/03/2023] Open
Abstract
Background: Malaria during pregnancy is a major health risk for both the mother and the foetus. Pregnancy has been shown to influence the pharmacokinetics of a number of different antimalarial drugs. This might lead to an under-exposure in these patients which could increase the risk of treatment failure and the development of drug resistance. The study aim was to evaluate the pharmacokinetics of artesunate and dihydroartemisinin in pregnant and non-pregnant patients using a population modelling approach. Methods: Twenty-four women in their second and third trimester of pregnancy and twenty-four paired non-pregnant women, all with uncomplicated P. falciparum malaria, were enrolled in this study. Treatment was a fixed-dose combination of oral artesunate and mefloquine once daily for three days. Frequent blood samples were collected and concentration-time data for artesunate and dihydroartemisinin were analysed simultaneously using nonlinear mixed-effects modelling. Results: Artesunate pharmacokinetics was best described by a transit-compartment absorption model followed by a one-compartment disposition model under the assumption of complete in vivo conversion of artesunate into dihydroartemisinin. Dihydroartemisinin pharmacokinetics was best described by a one-compartment disposition model with first-order elimination. Pregnant women had a 21% higher elimination clearance of dihydroartemisinin, compared to non-pregnant women, resulting in proportionally lower drug exposure. In addition, initial parasitaemia and liver status (alanine aminotransferase) were found to affect the relative bioavailability of artesunate. Conclusions: Results presented here show a substantially lower drug exposure to the antimalarial drug dihydroartemisinin during pregnancy after standard oral treatment of artesunate and mefloquine. This might result in an increased risk of treatment failure and drug resistance development, especially in low transmission settings where relative immunity is lower. Trial registration: ClinicalTrials.gov NCT00701961 (19/06/2008).
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Birgersson S, Valea I, Tinto H, Traore-Coulibaly M, Toe LC, Hoglund RM, Van Geertruyden JP, Ward SA, D’Alessandro U, Abelö A, Tarning J. Population pharmacokinetics of artesunate and dihydroartemisinin in pregnant and non-pregnant women with uncomplicated Plasmodium falciparum malaria in Burkina Faso: an open label trial. Wellcome Open Res 2019. [DOI: 10.12688/wellcomeopenres.14849.1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Background: Malaria during pregnancy is a major health risk for both the mother and the foetus. Pregnancy has been shown to influence the pharmacokinetics of a number of different antimalarial drugs. This might lead to an under-exposure in these patients which could increase the risk of treatment failure and the development of drug resistance. The study aim was to evaluate the pharmacokinetics of artesunate and dihydroartemisinin in pregnant and non-pregnant patients using a population modelling approach. Methods: Twenty-four women in their second and third trimester of pregnancy and twenty-four paired non-pregnant women, all with uncomplicated P. falciparum malaria, were enrolled in this study. Treatment was a fixed-dose combination of oral artesunate and mefloquine once daily for three days. Frequent blood samples were collected and concentration-time data for artesunate and dihydroartemisinin were analysed simultaneously using nonlinear mixed-effects modelling. Results: Artesunate pharmacokinetics was best described by a transit-compartment absorption model followed by a one-compartment disposition model under the assumption of complete in vivo conversion of artesunate into dihydroartemisinin. Dihydroartemisinin pharmacokinetics was best described by a one-compartment disposition model with first-order elimination. Pregnant women had a 21% higher elimination clearance of dihydroartemisinin, compared to non-pregnant women, resulting in proportionally lower drug exposure. In addition, initial parasitaemia and liver status (alanine aminotransferase) were found to affect the relative bioavailability of artesunate. Conclusions: Results presented here show a substantially lower drug exposure to the antimalarial drug dihydroartemisinin during pregnancy after standard oral treatment of artesunate and mefloquine. This might result in an increased risk of treatment failure and drug resistance development, especially in low transmission settings where relative immunity is lower. Trial registration: ClinicalTrials.gov NCT00701961 (19/06/2008)
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von Geldern TW, Morton HE, Clark RF, Brown BS, Johnston KL, Ford L, Specht S, Carr RA, Stolarik DF, Ma J, Rieser MJ, Struever D, Frohberger SJ, Koschel M, Ehrens A, Turner JD, Hübner MP, Hoerauf A, Taylor MJ, Ward SA, Marsh K, Kempf DJ. Discovery of ABBV-4083, a novel analog of Tylosin A that has potent anti-Wolbachia and anti-filarial activity. PLoS Negl Trop Dis 2019; 13:e0007159. [PMID: 30818326 PMCID: PMC6413952 DOI: 10.1371/journal.pntd.0007159] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2018] [Revised: 03/12/2019] [Accepted: 01/15/2019] [Indexed: 12/02/2022] Open
Abstract
There is a significant need for improved treatments for onchocerciasis and lymphatic filariasis, diseases caused by filarial worm infection. In particular, an agent able to selectively kill adult worms (macrofilaricide) would be expected to substantially augment the benefits of mass drug administration (MDA) with current microfilaricides, and to provide a solution to treatment of onchocerciasis / loiasis co-infection, where MDA is restricted. We have identified a novel macrofilaricidal agent, Tylosin A (TylA), which acts by targeting the worm-symbiont Wolbachia bacterium. Chemical modification of TylA leads to improvements in anti-Wolbachia activity and oral pharmacokinetic properties; an optimized analog (ABBV-4083) has been selected for clinical evaluation.
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Clare RH, Bardelle C, Harper P, Hong WD, Börjesson U, Johnston KL, Collier M, Myhill L, Cassidy A, Plant D, Plant H, Clark R, Cook DAN, Steven A, Archer J, McGillan P, Charoensutthivarakul S, Bibby J, Sharma R, Nixon GL, Slatko BE, Cantin L, Wu B, Turner J, Ford L, Rich K, Wigglesworth M, Berry NG, O'Neill PM, Taylor MJ, Ward SA. Industrial scale high-throughput screening delivers multiple fast acting macrofilaricides. Nat Commun 2019; 10:11. [PMID: 30602718 PMCID: PMC6315057 DOI: 10.1038/s41467-018-07826-2] [Citation(s) in RCA: 53] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2018] [Accepted: 11/29/2018] [Indexed: 01/22/2023] Open
Abstract
Nematodes causing lymphatic filariasis and onchocerciasis rely on their bacterial endosymbiont, Wolbachia, for survival and fecundity, making Wolbachia a promising therapeutic target. Here we perform a high-throughput screen of AstraZeneca’s 1.3 million in-house compound library and identify 5 novel chemotypes with faster in vitro kill rates (<2 days) than existing anti-Wolbachia drugs that cure onchocerciasis and lymphatic filariasis. This industrial scale anthelmintic neglected tropical disease (NTD) screening campaign is the result of a partnership between the Anti-Wolbachia consortium (A∙WOL) and AstraZeneca. The campaign was informed throughout by rational prioritisation and triage of compounds using cheminformatics to balance chemical diversity and drug like properties reducing the chance of attrition from the outset. Ongoing development of these multiple chemotypes, all with superior time-kill kinetics than registered antibiotics with anti-Wolbachia activity, has the potential to improve upon the current therapeutic options and deliver improved, safer and more selective macrofilaricidal drugs. Parasitic nematodes causing onchocerciasis and lymphatic filariasis rely on a bacterial endosymbiont, Wolbachia, which is a validated therapeutic target. Here, Clare et al. perform a high-throughput screen of 1.3 million compounds and identify 5 chemotypes with faster kill rates than existing anti-Wolbachia drugs.
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David Hong W, Leung SC, Amporndanai K, Davies J, Priestley RS, Nixon GL, Berry NG, Samar Hasnain S, Antonyuk S, Ward SA, Biagini GA, O’Neill PM. Potent Antimalarial 2-Pyrazolyl Quinolone bc 1 (Q i) Inhibitors with Improved Drug-like Properties. ACS Med Chem Lett 2018; 9:1205-1210. [PMID: 30613327 DOI: 10.1021/acsmedchemlett.8b00371] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2018] [Accepted: 10/19/2018] [Indexed: 01/29/2023] Open
Abstract
A series of 2-pyrazolyl quinolones has been designed and synthesized in 5-7 steps to optimize for both in vitro antimalarial potency and various in vitro drug metabolism and pharmacokinetics (DMPK) features. The most potent compounds display no cross-resistance with multidrug resistant parasite strains (W2) compared to drug sensitive strains (3D7), with IC50 (concentration of drug required to achieve half maximal growth suppression) values in the range of 15-33 nM. Furthermore, members of the series retain moderate activity against the atovaquone-resistant parasite isolate (TM90C2B). The described 2-pyrazoyl series displays improved DMPK properties, including improved aqueous solubility compared to previously reported quinolone series and acceptable safety margin through in vitro cytotoxicity assessment. The 2-pyrazolyl quinolones are believed to bind to the ubiquinone-reducing Qi site of the parasite bc 1 complex, which is supported by crystallographic studies of bovine cytochrome bc 1 complex.
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Nkhoma SC, Banda RL, Khoswe S, Dzoole-Mwale TJ, Ward SA. Intra-host dynamics of co-infecting parasite genotypes in asymptomatic malaria patients. INFECTION, GENETICS AND EVOLUTION : JOURNAL OF MOLECULAR EPIDEMIOLOGY AND EVOLUTIONARY GENETICS IN INFECTIOUS DISEASES 2018; 65:414-424. [PMID: 30145390 PMCID: PMC6219893 DOI: 10.1016/j.meegid.2018.08.018] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/29/2018] [Revised: 08/13/2018] [Accepted: 08/20/2018] [Indexed: 11/22/2022]
Abstract
Malaria-infected individuals often harbor mixtures of genetically distinct parasite genotypes. We studied intra-host dynamics of parasite genotypes co-infecting asymptomatic adults in an area of intense malaria transmission in Chikhwawa, Malawi. Serial blood samples (5 ml) were collected over seven consecutive days from 25 adults with asymptomatic Plasmodium falciparum malaria and analyzed to determine whether a single peripheral blood sample accurately captures within-host parasite diversity. Blood samples from three of the participants were also analyzed by limiting dilution cloning and SNP genotyping of the parasite clones isolated to examine both the number and relatedness of co-infecting parasite haplotypes. We observed rapid turnover of co-infecting parasite genotypes in 88% of the individuals sampled (n = 22) such that the genetic composition of parasites infecting these individuals changed dramatically over the course of seven days of follow up. Nineteen of the 25 individuals sampled (76%) carried multiple parasite genotypes at baseline. Analysis of serial blood samples from three of the individuals revealed that they harbored 6, 12 and 17 distinct parasite haplotypes respectively. Approximately 70% of parasite haplotypes recovered from the three extensively sampled individuals were unrelated (proportion of shared alleles <83.3%) and were deemed to have primarily arisen from superinfection (inoculation of unrelated parasite haplotypes through multiple mosquito bites). The rest were related at the half-sib level or greater and were deemed to have been inoculated into individual human hosts via parasite co-transmission from single mosquito bites. These findings add further to the growing weight of evidence indicating that a single blood sample poorly captures within-host parasite diversity and underscore the importance of repeated blood sampling to accurately capture within-host parasite ecology. Our data also demonstrate a more pronounced role for parasite co-transmission in generating within-host parasite diversity in high transmission settings than previously assumed. Taken together, these findings have important implications for understanding the evolution of drug resistance, malaria transmission, parasite virulence, allocation of gametocyte sex ratios and acquisition of malaria immunity.
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Wu PP, He H, Hong WD, Wu TR, Huang GY, Zhong YY, Tu BR, Gao M, Zhou J, Zhao SQ, Li DL, Xu XT, Sheng ZJ, Ward SA, O'Neill PM, Zhang K. The biological evaluation of fusidic acid and its hydrogenation derivative as antimicrobial and anti-inflammatory agents. Infect Drug Resist 2018; 11:1945-1957. [PMID: 30498366 PMCID: PMC6207271 DOI: 10.2147/idr.s176390] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
Background Fusidic acid (FA) (WU-FA-00) is the only commercially available antimicrobial from the fusidane family that has a narrow spectrum of activity against Gram-positive bacteria. Methods Herein, the hydrogenation derivative (WU-FA-01) of FA was prepared and both compounds were examined against a panel of six bacterial strains. In addition, their anti-inflammatory properties were evaluated using a 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced mouse ear edema model. Results The results of the antimicrobial assay revealed that both WU-FA-00 and WU-FA-01 displayed a high level of antimicrobial activity against Gram-positive strains. Moreover, killing kinetic studies were performed and the results were in accordance with the minimum inhibitory concentration and minimum bactericidal concentration results. We also demonstrated that the topical application of WU-FA-00 and WU-FA-01 effectively decreased TPA-induced ear edema in a dose-dependent manner. This inhibitory effect was associated with the inhibition of TPA-induced upregulation of proinflammatory cytokines IL-1β, TNF-α, and COX-2. WU-FA-01 significantly suppressed the expression levels of p65, IκB-α, and p-IκB-α in the TPA-induced mouse ear model. Conclusion Overall, our results showed that WU-FA-00 and WU-FA-01 not only had effective antimicrobial activities in vitro, especially to the Gram-positive bacteria, but also possessed strong anti-inflammatory effects in vivo. These results provide a scientific basis for developing FA derivatives as antimicrobial and anti-inflammatory agents.
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Smit MR, Ochomo EO, Waterhouse D, Kwambai TK, Abong'o BO, Bousema T, Bayoh NM, Gimnig JE, Samuels AM, Desai MR, Phillips-Howard PA, Kariuki SK, Wang D, Ter Kuile FO, Ward SA, Aljayyoussi G. Pharmacokinetics-Pharmacodynamics of High-Dose Ivermectin with Dihydroartemisinin-Piperaquine on Mosquitocidal Activity and QT-Prolongation (IVERMAL). Clin Pharmacol Ther 2018; 105:388-401. [PMID: 30125353 PMCID: PMC6585895 DOI: 10.1002/cpt.1219] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2018] [Accepted: 08/05/2018] [Indexed: 12/26/2022]
Abstract
High‐dose ivermectin, co‐administered for 3 days with dihydroartemisinin‐piperaquine (DP), killed mosquitoes feeding on individuals for at least 28 days posttreatment in a recent trial (IVERMAL), whereas 7 days was predicted pretrial. The current study assessed the relationship between ivermectin blood concentrations and the observed mosquitocidal effects against Anopheles gambiae s.s. Three days of ivermectin 0, 300, or 600 mcg/kg/day plus DP was randomly assigned to 141 adults with uncomplicated malaria in Kenya. During 28 days of follow‐up, 1,393 venous and 335 paired capillary plasma samples, 850 mosquito‐cluster mortality rates, and 524 QTcF‐intervals were collected. Using pharmacokinetic/pharmacodynamic (PK/PD) modeling, we show a consistent correlation between predicted ivermectin concentrations and observed mosquitocidal‐effects throughout the 28‐day study duration, without invoking an unidentified mosquitocidal metabolite or drug‐drug interaction. Ivermectin had no effect on piperaquine's PKs or QTcF‐prolongation. The PK/PD model can be used to design new treatment regimens with predicted mosquitocidal effect. This methodology could be used to evaluate effectiveness of other endectocides.
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O' Neill PM, Stocks PA, Sabbani S, Roberts NL, Amewu RK, Shore ER, Aljayyoussi G, Angulo-Barturén I, Belén M, Jiménez-Díaz, Bazaga SF, Martínez MS, Campo B, Sharma R, Charman SA, Ryan E, Chen G, Shackleford DM, Davies J, Nixon GL, Biagini GA, Ward SA. Synthesis and profiling of benzylmorpholine 1,2,4,5-tetraoxane analogue N205: Towards tetraoxane scaffolds with potential for single dose cure of malaria. Bioorg Med Chem 2018; 26:2996-3005. [DOI: 10.1016/j.bmc.2018.05.006] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2018] [Revised: 05/03/2018] [Accepted: 05/04/2018] [Indexed: 01/08/2023]
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Aljayyoussi G, Tyrer HE, Ford L, Sjoberg H, Pionnier N, Waterhouse D, Davies J, Gamble J, Metuge H, Cook DAN, Steven A, Sharma R, Guimaraes AF, Clare RH, Cassidy A, Johnston KL, Myhill L, Hayward L, Wanji S, Turner JD, Taylor MJ, Ward SA. Author Correction: Short-Course, High-Dose Rifampicin Achieves Wolbachia Depletion Predictive of Curative Outcomes in Preclinical Models of Lymphatic Filariasis and Onchocerciasis. Sci Rep 2018; 8:1384. [PMID: 29348597 PMCID: PMC5773522 DOI: 10.1038/s41598-018-19723-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
A correction to this article has been published and is linked from the HTML version of this paper. The error has been fixed in the paper.
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Sharma R, Aljayyoussi G, Tyrer HE, Gamble J, Hayward L, Guimaraes AF, Davies J, Waterhouse D, Cook DAN, Myhill LJ, Clare RH, Cassidy A, Steven A, Johnston KL, Ford L, Turner JD, Ward SA, Taylor MJ. Corrigendum: Minocycline as a re-purposed anti-Wolbachia macrofilaricide: superiority compared with doxycycline regimens in a murine infection model of human lymphatic filariasis. Sci Rep 2018; 8:46934. [PMID: 29308790 PMCID: PMC5757190 DOI: 10.1038/srep46934] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
This corrects the article DOI: 10.1038/srep23458.
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Török ME, Aljayyoussi G, Waterhouse D, Chau T, Mai N, Phu NH, Hien TT, Hope W, Farrar JJ, Ward SA. Suboptimal Exposure to Anti-TB Drugs in a TBM/HIV+ Population Is Not Related to Antiretroviral Therapy. Clin Pharmacol Ther 2017; 103:449-457. [PMID: 28160272 DOI: 10.1002/cpt.646] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2016] [Revised: 01/24/2017] [Accepted: 01/29/2017] [Indexed: 11/08/2022]
Abstract
A placebo-controlled trial that compares the outcomes of immediate vs. deferred initiation of antiretroviral therapy in HIV +ve tuberculous meningitis (TBM) patients was conducted in Vietnam in 2011. Here, the pharmacokinetics of rifampicin, isoniazid, pyrazinamide, and ethambutol were investigated in the presence and absence of anti-HIV treatment in 85 patients. Pharmacokinetic analyses show that HIV therapy has no significant impact on the pharmacokinetics of TB drugs in this cohort. The same population, however, displayed generally low cerebrospinal fluid (CSF) and systemic exposures to rifampicin compared to previously reported HIV -ve cohorts. Elevated CSF concentrations of pyrazinamide, on the other hand, were strongly and independently correlated with increased mortality and neurological toxicity. The findings suggest that the current standard dosing regimens may put the patient at risk of treatment failure from suboptimal rifampicin exposure, and potentially increasing the risk of adverse central nervous system events that are independently correlated with pyrazinamide CSF exposure.
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Johnston KL, Cook DAN, Berry NG, David Hong W, Clare RH, Goddard M, Ford L, Nixon GL, O’Neill PM, Ward SA, Taylor MJ. Identification and prioritization of novel anti- Wolbachia chemotypes from screening a 10,000-compound diversity library. SCIENCE ADVANCES 2017; 3:eaao1551. [PMID: 28959730 PMCID: PMC5617373 DOI: 10.1126/sciadv.aao1551] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/20/2017] [Accepted: 09/01/2017] [Indexed: 06/07/2023]
Abstract
Lymphatic filariasis and onchocerciasis are two important neglected tropical diseases (NTDs) that cause severe disability. Control efforts are hindered by the lack of a safe macrofilaricidal drug. Targeting the Wolbachia bacterial endosymbionts in these parasites with doxycycline leads to a macrofilaricidal outcome, but protracted treatment regimens and contraindications restrict its widespread implementation. The Anti-Wolbachia consortium aims to develop improved anti-Wolbachia drugs to overcome these barriers. We describe the first screening of a large, diverse compound library against Wolbachia. This whole-organism screen, streamlined to reduce bottlenecks, produced a hit rate of 0.5%. Chemoinformatic analysis of the top 50 hits led to the identification of six structurally diverse chemotypes, the disclosure of which could offer interesting avenues of investigation to other researchers active in this field. An example of hit-to-lead optimization is described to further demonstrate the potential of developing these high-quality hit series as safe, efficacious, and selective anti-Wolbachia macrofilaricides.
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Hong WD, Gibbons PD, Leung SC, Amewu R, Stocks PA, Stachulski A, Horta P, Cristiano MLS, Shone AE, Moss D, Ardrey A, Sharma R, Warman AJ, Bedingfield PTP, Fisher NE, Aljayyoussi G, Mead S, Caws M, Berry NG, Ward SA, Biagini GA, O'Neill PM, Nixon GL. Rational Design, Synthesis, and Biological Evaluation of Heterocyclic Quinolones Targeting the Respiratory Chain of Mycobacterium tuberculosis. J Med Chem 2017; 60:3703-3726. [PMID: 28304162 DOI: 10.1021/acs.jmedchem.6b01718] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
A high-throughput screen (HTS) was undertaken against the respiratory chain dehydrogenase component, NADH:menaquinone oxidoreductase (Ndh) of Mycobacterium tuberculosis (Mtb). The 11000 compounds were selected for the HTS based on the known phenothiazine Ndh inhibitors, trifluoperazine and thioridazine. Combined HTS (11000 compounds) and in-house screening of a limited number of quinolones (50 compounds) identified ∼100 hits and four distinct chemotypes, the most promising of which contained the quinolone core. Subsequent Mtb screening of the complete in-house quinolone library (350 compounds) identified a further ∼90 hits across three quinolone subtemplates. Quinolones containing the amine-based side chain were selected as the pharmacophore for further modification, resulting in metabolically stable quinolones effective against multi drug resistant (MDR) Mtb. The lead compound, 42a (MTC420), displays acceptable antituberculosis activity (Mtb IC50 = 525 nM, Mtb Wayne IC50 = 76 nM, and MDR Mtb patient isolates IC50 = 140 nM) and favorable pharmacokinetic and toxicological profiles.
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Mungthin M, Watanatanasup E, Sitthichot N, Suwandittakul N, Khositnithikul R, Ward SA. Influence of the pfmdr1 Gene on In Vitro Sensitivities of Piperaquine in Thai Isolates of Plasmodium falciparum. Am J Trop Med Hyg 2017; 96:624-629. [PMID: 28044042 DOI: 10.4269/ajtmh.16-0668] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Piperaquine combined with dihydroartemisinin is one of the artemisinin derivative combination therapies, which can replace artesunate-mefloquine in treating uncomplicated falciparum malaria in Thailand. The aim of this study was to determine the in vitro sensitivity of Thai Plasmodium falciparum isolates against piperaquine and the influence of the pfmdr1 gene on in vitro response. One hundred and thirty-seven standard laboratory and adapted Thai isolates of P. falciparum were assessed for in vitro piperaquine sensitivity. Polymorphisms of the pfmdr1 gene were determined by polymerase chain reaction methods. The mean and standard deviation of the piperaquine IC50 in Thai isolates of P. falciparum were 16.7 ± 6.3 nM. The parasites exhibiting chloroquine IC50 of ≥ 100 nM were significantly less sensitive to piperaquine compared with the parasite with chloroquine IC50 of < 100 nM. No significant association between the pfmdr1 copy number and piperaquine IC50 values was found. In contrast, the parasites containing the pfmdr1 86Y allele exhibited significantly reduced piperaquine sensitivity. Before nationwide implementation of dihydroartemisinin-piperaquine as the first-line treatment in Thailand, in vitro and in vivo evaluations of this combination should be performed especially in areas where parasites containing the pfmdr1 86Y allele are predominant such as the Thai-Malaysian border.
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Aljayyoussi G, Tyrer HE, Ford L, Sjoberg H, Pionnier N, Waterhouse D, Davies J, Gamble J, Metuge H, Cook DAN, Steven A, Sharma R, Guimaraes AF, Clare RH, Cassidy A, Johnston KL, Myhill L, Hayward L, Wanji S, Turner JD, Taylor MJ, Ward SA. Short-Course, High-Dose Rifampicin Achieves Wolbachia Depletion Predictive of Curative Outcomes in Preclinical Models of Lymphatic Filariasis and Onchocerciasis. Sci Rep 2017; 7:210. [PMID: 28303006 PMCID: PMC5428297 DOI: 10.1038/s41598-017-00322-5] [Citation(s) in RCA: 53] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2016] [Accepted: 02/21/2017] [Indexed: 12/29/2022] Open
Abstract
Lymphatic filariasis (LF) and onchocerciasis are priority neglected tropical diseases targeted for elimination. The only safe drug treatment with substantial curative activity against the filarial nematodes responsible for LF (Brugia malayi, Wuchereria bancrofti) or onchocerciasis (Onchocerca volvulus) is doxycycline. The target of doxycycline is the essential endosymbiont, Wolbachia. Four to six weeks doxycycline therapy achieves >90% depletion of Wolbachia in worm tissues leading to blockade of embryogenesis, adult sterility and premature death 18-24 months post-treatment. Long treatment length and contraindications in children and pregnancy are obstacles to implementing doxycycline as a public health strategy. Here we determine, via preclinical infection models of Brugia malayi or Onchocerca ochengi that elevated exposures of orally-administered rifampicin can lead to Wolbachia depletions from filariae more rapidly than those achieved by doxycycline. Dose escalation of rifampicin achieves >90% Wolbachia depletion in time periods of 7 days in B. malayi and 14 days in O. ochengi. Using pharmacokinetic-pharmacodynamic modelling and mouse-human bridging analysis, we conclude that clinically relevant dose elevations of rifampicin, which have recently been determined as safe in humans, could be administered as short courses to filariasis target populations with potential to reduce anti-Wolbachia curative therapy times to between one and two weeks.
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Jiang Z, Hong WD, Cui X, Gao H, Wu P, Chen Y, Shen D, Yang Y, Zhang B, Taylor MJ, Ward SA, O'Neill PM, Zhao S, Zhang K. Synthesis and structure–activity relationship of N4-benzylamine-N2-isopropyl-quinazoline-2,4-diamines derivatives as potential antibacterial agents. RSC Adv 2017. [DOI: 10.1039/c7ra10352b] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
This paper investigated the SAR of the N4-benzylamine-N2-isopropyl-quinazoline-2,4-diamines derivatives with heterocyclic scaffold which showed good activities against S. aureus, E. coli, MRSA, S. epidermidis and S. typhimurium.
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O' Neill PM, Sabbani S, Nixon GL, Schnaderbeck M, Roberts NL, Shore ER, Riley C, Murphy B, McGillan P, Ward SA, Davies J, Amewu RK. Optimisation of the synthesis of second generation 1,2,4,5 tetraoxane antimalarials. Tetrahedron 2016. [DOI: 10.1016/j.tet.2016.08.043] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
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Ismail HM, Barton VE, Panchana M, Charoensutthivarakul S, Biagini GA, Ward SA, O'Neill PM. Berichtigung: A Click Chemistry-Based Proteomic Approach Reveals that 1,2,4-Trioxolane and Artemisinin Antimalarials Share a Common Protein Alkylation Profile. Angew Chem Int Ed Engl 2016. [DOI: 10.1002/ange.201607032] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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Ismail HM, Barton VE, Panchana M, Charoensutthivarakul S, Biagini GA, Ward SA, O'Neill PM. Corrigendum: A Click Chemistry-Based Proteomic Approach Reveals that 1,2,4-Trioxolane and Artemisinin Antimalarials Share a Common Protein Alkylation Profile. Angew Chem Int Ed Engl 2016; 55:10548. [PMID: 27552550 DOI: 10.1002/anie.201607032] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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Aljayyoussi G, Kay K, Ward SA, Biagini GA. OptiMal-PK: an internet-based, user-friendly interface for the mathematical-based design of optimized anti-malarial treatment regimens. Malar J 2016; 15:344. [PMID: 27388207 PMCID: PMC4936002 DOI: 10.1186/s12936-016-1401-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2016] [Accepted: 06/17/2016] [Indexed: 01/26/2023] Open
Abstract
Background The search for highly effective anti-malarial therapies has gathered pace and recent years have seen a number of promising single and combined therapies reach the late stages of development. A key drug development challenge is the need for early assessment of the clinical utility of new drug leads as it is often unclear for developers whether efforts should be focused on efficacy or metabolic stability/exposure or indeed whether the continuation of iterative QSAR (quantitative structure–activity and relationships) cycles of medicinal chemistry and biological testing will translate to improved clinical efficacy. Pharmacokinetic and pharmacodynamic (PK/PD)-based measurements available from in vitro studies can be used for such clinical predictions. However, these predictions often require bespoke mathematical PK/PD modelling expertise and are normally performed after candidate development and, therefore, not during the pre-clinical development phase when such decisions need to be made. Methods An internet-based tool has been developed using STELLA® software. The tool simulates multiple differential equations that describe anti-malarial PK/PD relationships where the user can easily input PK/PD parameters. The tool utilizes a simple stop-light system to indicate the efficacy of each combination of parameters. This tool, called OptiMal-PK, additionally allows for the investigation of the effect of drug combinations with known or custom compounds. Results The results of simulations obtained from OptiMal-PK were compared to a previously published and validated mathematical model on which this tool is based. The tool has also been used to simulate the PK/PD relationship for a number of existing anti-malarial drugs in single or combined treatment. Simulations were predictive of the published clinical parasitological clearance activities for these existing therapies. Conclusions OptiMal-PK is designed to be implemented by medicinal chemists and pharmacologists during the pre-clinical anti-malarial drug development phase to explore the impact of different PK/PD parameters upon the predicted clinical activity of any new compound. It can help investigators to identify which pharmacological features of a compound are most important to the clinical performance of a new chemical entity and how partner drugs could potentially improve the activity of existing therapies.
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Sahota AS, Gowda R, Arasaradnam RP, Daulton E, Savage RS, Skinner JR, Adams E, Ward SA, Covington JA. A simple breath test for tuberculosis using ion mobility: A pilot study. Tuberculosis (Edinb) 2016; 99:143-146. [PMID: 27450016 DOI: 10.1016/j.tube.2016.05.005] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2016] [Revised: 05/18/2016] [Accepted: 05/22/2016] [Indexed: 11/26/2022]
Abstract
Tuberculosis (TB) remains one of the world's major health burdens with 9.6 million new infections globally. Though considerable progress has been made in reduction of TB incidence and mortality, there is a continuous need for lower cost, simpler and more robust means of diagnosis. One method that may fulfil these requirements is in the area of breath analysis. In this study we analysed the breath of 21 patients with pulmonary or extra-pulmonary TB, recruited from a UK teaching hospital (University Hospital Coventry and Warwickshire) before or within 1 week of commencing treatment for TB. TB diagnosis was confirmed by reference tests (mycobacterial culture), histology or radiology. 19 controls were recruited to calculate specificity; these patients were all interferon-gamma release assay negative (T.SPOT(®).TB, Oxford Immunotec Ltd.). Whole breath samples were collected with subsequent chemical analysis undertaken by Ion Mobility Spectrometry. Our results produced a sensitivity of 81% and a specificity of 79% for all cases of TB (pulmonary and extra-pulmonary). Though lower than other studies analysing pulmonary TB alone, we believe that this technique shows promise, and a higher sensitivity could be achieved by further improving our sample capture methodology.
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Ismail HM, Barton VE, Panchana M, Charoensutthivarakul S, Biagini GA, Ward SA, O'Neill PM. A Click Chemistry-Based Proteomic Approach Reveals that 1,2,4-Trioxolane and Artemisinin Antimalarials Share a Common Protein Alkylation Profile. ANGEWANDTE CHEMIE (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2016; 128:6511-6515. [PMID: 27397940 PMCID: PMC4934454 DOI: 10.1002/ange.201512062] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/31/2015] [Revised: 02/19/2016] [Indexed: 12/12/2022]
Abstract
In spite of the recent increase in endoperoxide antimalarials under development, it remains unclear if all these chemotypes share a common mechanism of action. This is important since it will influence cross-resistance risks between the different classes. Here we investigate this proposition using novel clickable 1,2,4-trioxolane activity based protein-profiling probes (ABPPs). ABPPs with potent antimalarial activity were able to alkylate protein target(s) within the asexual erythrocytic stage of Plasmodium falciparum (3D7). Importantly, comparison of the alkylation fingerprint with that generated from an artemisinin ABPP equivalent confirms a highly conserved alkylation profile, with both endoperoxide classes targeting proteins in the glycolytic, hemoglobin degradation, antioxidant defence, protein synthesis and protein stress pathways, essential biological processes for plasmodial survival. The alkylation signatures of the two chemotypes show significant overlap (ca. 90 %) both qualitatively and semi-quantitatively, suggesting a common mechanism of action that raises concerns about potential cross-resistance liabilities.
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