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Ogbonna EN, Paul A, Ross Terrell J, Fang Z, Chen C, Poon GMK, Boykin DW, Wilson WD. Drug design and DNA structural research inspired by the Neidle laboratory: DNA minor groove binding and transcription factor inhibition by thiophene diamidines. Bioorg Med Chem 2022; 68:116861. [PMID: 35661929 DOI: 10.1016/j.bmc.2022.116861] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2022] [Revised: 05/23/2022] [Accepted: 05/26/2022] [Indexed: 11/02/2022]
Abstract
The understanding of sequence-specific DNA minor groove interactions has recently made major steps forward and as a result, the goal of development of compounds that target the minor groove is an active research area. In an effort to develop biologically active minor groove agents, we are preparing and exploring the DNA interactions of diverse diamidine derivatives with a 5'-GAATTC-3' binding site using a powerful array of methods including, biosensor-SPR methods, and X-ray crystallography. The benzimidazole-thiophene module provides an excellent minor groove recognition component. A central thiophene in a benzimidazole-thiophene-phenyl aromatic system provides essentially optimum curvature for matching the shape of the minor groove. Comparison of that structure to one with the benzimidazole replaced with an indole shows that the two structures are very similar, but have some interesting and important differences in electrostatic potential maps, the DNA minor groove binding structure based on x-ray crystallographic analysis, and inhibition of the major groove binding PU.1 transcription factor complex. The binding KD for both compounds is under 10 nM and both form amidine H-bonds to DNA bases. They both have bifurcated H-bonds from the benzimidazole or indole groups to bases at the center of the -AATT- binding site. Analysis of the comparative results provides an excellent understanding of how thiophene compounds recognize the minor groove and can act as transcription factor inhibitors.
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Affiliation(s)
- Edwin N Ogbonna
- Department of Chemistry and Center for Diagnostics and Therapeutics, Georgia State University, Atlanta, GA 30303-3083, USA
| | - Ananya Paul
- Department of Chemistry and Center for Diagnostics and Therapeutics, Georgia State University, Atlanta, GA 30303-3083, USA
| | - J Ross Terrell
- Department of Chemistry and Center for Diagnostics and Therapeutics, Georgia State University, Atlanta, GA 30303-3083, USA
| | - Ziyuan Fang
- Department of Chemistry and Center for Diagnostics and Therapeutics, Georgia State University, Atlanta, GA 30303-3083, USA
| | - Cen Chen
- Department of Chemistry and Center for Diagnostics and Therapeutics, Georgia State University, Atlanta, GA 30303-3083, USA
| | - Gregory M K Poon
- Department of Chemistry and Center for Diagnostics and Therapeutics, Georgia State University, Atlanta, GA 30303-3083, USA
| | - David W Boykin
- Department of Chemistry and Center for Diagnostics and Therapeutics, Georgia State University, Atlanta, GA 30303-3083, USA
| | - W David Wilson
- Department of Chemistry and Center for Diagnostics and Therapeutics, Georgia State University, Atlanta, GA 30303-3083, USA.
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Dickie EA, Giordani F, Gould MK, Mäser P, Burri C, Mottram JC, Rao SPS, Barrett MP. New Drugs for Human African Trypanosomiasis: A Twenty First Century Success Story. Trop Med Infect Dis 2020; 5:tropicalmed5010029. [PMID: 32092897 PMCID: PMC7157223 DOI: 10.3390/tropicalmed5010029] [Citation(s) in RCA: 66] [Impact Index Per Article: 16.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2020] [Revised: 02/12/2020] [Accepted: 02/14/2020] [Indexed: 12/23/2022] Open
Abstract
The twentieth century ended with human African trypanosomiasis (HAT) epidemics raging across many parts of Africa. Resistance to existing drugs was emerging, and many programs aiming to contain the disease had ground to a halt, given previous success against HAT and the competing priorities associated with other medical crises ravaging the continent. A series of dedicated interventions and the introduction of innovative routes to develop drugs, involving Product Development Partnerships, has led to a dramatic turnaround in the fight against HAT caused by Trypanosoma brucei gambiense. The World Health Organization have been able to optimize the use of existing tools to monitor and intervene in the disease. A promising new oral medication for stage 1 HAT, pafuramidine maleate, ultimately failed due to unforeseen toxicity issues. However, the clinical trials for this compound demonstrated the possibility of conducting such trials in the resource-poor settings of rural Africa. The Drugs for Neglected Disease initiative (DNDi), founded in 2003, has developed the first all oral therapy for both stage 1 and stage 2 HAT in fexinidazole. DNDi has also brought forward another oral therapy, acoziborole, potentially capable of curing both stage 1 and stage 2 disease in a single dosing. In this review article, we describe the remarkable successes in combating HAT through the twenty first century, bringing the prospect of the elimination of this disease into sight.
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Affiliation(s)
- Emily A. Dickie
- Wellcome Centre for Integrative Parasitology, Institute of Infection, Immunity and Inflammation, University of Glasgow, Glasgow G12 8TA, UK; (E.A.D.); (F.G.); (M.K.G.)
| | - Federica Giordani
- Wellcome Centre for Integrative Parasitology, Institute of Infection, Immunity and Inflammation, University of Glasgow, Glasgow G12 8TA, UK; (E.A.D.); (F.G.); (M.K.G.)
| | - Matthew K. Gould
- Wellcome Centre for Integrative Parasitology, Institute of Infection, Immunity and Inflammation, University of Glasgow, Glasgow G12 8TA, UK; (E.A.D.); (F.G.); (M.K.G.)
| | - Pascal Mäser
- Swiss Tropical and Public Health Institute, Socinstrasse 57, 4002 Basel, Switzerland; (P.M.); (C.B.)
| | - Christian Burri
- Swiss Tropical and Public Health Institute, Socinstrasse 57, 4002 Basel, Switzerland; (P.M.); (C.B.)
- University of Basel, Petersplatz 1, 4000 Basel, Switzerland
| | - Jeremy C. Mottram
- York Biomedical Research Institute, Department of Biology, University of York, Wentworth Way, Heslington, York YO10 5DD, UK;
| | - Srinivasa P. S. Rao
- Novartis Institute for Tropical Diseases, 5300 Chiron Way, Emeryville, CA 94608, USA;
| | - Michael P. Barrett
- Wellcome Centre for Integrative Parasitology, Institute of Infection, Immunity and Inflammation, University of Glasgow, Glasgow G12 8TA, UK; (E.A.D.); (F.G.); (M.K.G.)
- Correspondence:
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Prokopienko AJ, West RE, Schrum DP, Stubbs JR, Leblond FA, Pichette V, Nolin TD. Metabolic Activation of Flavin Monooxygenase-mediated Trimethylamine-N-Oxide Formation in Experimental Kidney Disease. Sci Rep 2019; 9:15901. [PMID: 31685846 PMCID: PMC6828678 DOI: 10.1038/s41598-019-52032-9] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2019] [Accepted: 10/12/2019] [Indexed: 12/25/2022] Open
Abstract
Cardiovascular disease (CVD) remains the leading cause of death in chronic kidney disease (CKD) patients despite treatment of traditional risk factors, suggesting that non-traditional CVD risk factors are involved. Trimethylamine-N-oxide (TMAO) correlates with atherosclerosis burden in CKD patients and may be a non-traditional CVD risk factor. Serum TMAO concentrations are significantly increased in CKD patients, which may be due in part to increased hepatic flavin monooxygenase (FMO)-mediated TMAO formation. The objective of this work was to elucidate the mechanism of increased FMO activity in CKD. In this study, FMO enzyme activity experiments were conducted in vitro with liver microsomes isolated from experimental CKD and control rats. Trimethylamine was used as a probe substrate to assess FMO activity. The FMO activator octylamine and human uremic serum were evaluated. FMO gene and protein expression were also determined. FMO-mediated TMAO formation was increased in CKD versus control. Although gene and protein expression of FMO were not changed, metabolic activation elicited by octylamine and human uremic serum increased FMO-mediated TMAO formation. The findings suggest that metabolic activation of FMO-mediated TMAO formation is a novel mechanism that contributes to increased TMAO formation in CKD and represents a therapeutic target to reduce TMAO exposure and CVD.
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Affiliation(s)
- Alexander J Prokopienko
- Center for Clinical Pharmaceutical Sciences, Department of Pharmaceutical Sciences or Department of Pharmacy and Therapeutics, School of Pharmacy, University of Pittsburgh, Pittsburgh, PA, United States
| | - Raymond E West
- Center for Clinical Pharmaceutical Sciences, Department of Pharmaceutical Sciences or Department of Pharmacy and Therapeutics, School of Pharmacy, University of Pittsburgh, Pittsburgh, PA, United States
| | - Daniel P Schrum
- Center for Clinical Pharmaceutical Sciences, Department of Pharmaceutical Sciences or Department of Pharmacy and Therapeutics, School of Pharmacy, University of Pittsburgh, Pittsburgh, PA, United States
| | - Jason R Stubbs
- The Kidney Institute, and Department of Internal Medicine, Division of Nephrology & Hypertension, University of Kansas Medical Center, Kansas City, KS, United States
| | | | - Vincent Pichette
- Service de Néphrologie et Centre de Recherche, Hôpital Maisonneuve-Rosemont, Département de Pharmacologie, Université de Montréal, Montréal, Québec, Canada
| | - Thomas D Nolin
- Center for Clinical Pharmaceutical Sciences, Department of Pharmaceutical Sciences or Department of Pharmacy and Therapeutics, School of Pharmacy, University of Pittsburgh, Pittsburgh, PA, United States.
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Poovi G, Damodharan N. Lipid nanoparticles: A challenging approach for oral delivery of BCS Class-II drugs. FUTURE JOURNAL OF PHARMACEUTICAL SCIENCES 2018. [DOI: 10.1016/j.fjps.2018.04.001] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
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Synthesis, biological characterisation and structure activity relationships of aromatic bisamidines active against Plasmodium falciparum. Eur J Med Chem 2017; 127:22-40. [DOI: 10.1016/j.ejmech.2016.12.041] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2016] [Revised: 12/19/2016] [Accepted: 12/20/2016] [Indexed: 01/27/2023]
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Burri C, Yeramian PD, Allen JL, Merolle A, Serge KK, Mpanya A, Lutumba P, Mesu VKBK, Bilenge CMM, Lubaki JPF, Mpoto AM, Thompson M, Munungu BF, Manuel F, Josenando T, Bernhard SC, Olson CA, Blum J, Tidwell RR, Pohlig G. Efficacy, Safety, and Dose of Pafuramidine, a New Oral Drug for Treatment of First Stage Sleeping Sickness, in a Phase 2a Clinical Study and Phase 2b Randomized Clinical Studies. PLoS Negl Trop Dis 2016; 10:e0004362. [PMID: 26881924 PMCID: PMC4755713 DOI: 10.1371/journal.pntd.0004362] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2015] [Accepted: 12/14/2015] [Indexed: 11/19/2022] Open
Abstract
Background Sleeping sickness (human African trypanosomiasis [HAT]) is caused by protozoan parasites and characterized by a chronic progressive course, which may last up to several years before death. We conducted two Phase 2 studies to determine the efficacy and safety of oral pafuramidine in African patients with first stage HAT. Methods The Phase 2a study was an open-label, non-controlled, proof-of-concept study where 32 patients were treated with 100 mg of pafuramidine orally twice a day (BID) for 5 days at two trypanosomiasis reference centers (Angola and the Democratic Republic of the Congo [DRC]) between August 2001 and November 2004. The Phase 2b study compared pafuramidine in 41 patients versus standard pentamidine therapy in 40 patients. The Phase 2b study was open-label, parallel-group, controlled, randomized, and conducted at two sites in the DRC between April 2003 and February 2007. The Phase 2b study was then amended to add an open-label sequence (Phase 2b-2), where 30 patients received pafuramidine for 10 days. The primary efficacy endpoint was parasitologic cure at 24 hours (Phase 2a) or 3 months (Phase 2b) after treatment completion. The primary safety outcome was the rate of occurrence of World Health Organization Toxicity Scale Grade 3 or higher adverse events. All subjects provided written informed consent. Findings/Conclusion Pafuramidine for the treatment of first stage HAT was comparable in efficacy to pentamidine after 10 days of dosing. The cure rates 3 months post-treatment were 79% in the 5-day pafuramidine, 100% in the 7-day pentamidine, and 93% in the 10-day pafuramidine groups. In Phase 2b, the percentage of patients with at least 1 treatment-emergent adverse event was notably higher after pentamidine treatment (93%) than pafuramidine treatment for 5 days (25%) and 10 days (57%). These results support continuation of the development program for pafuramidine into Phase 3. Sleeping sickness (human African trypanosomiasis [HAT]) is caused by parasites, and has a chronic progressive course that may last from several months to several years before death occurs. The present studies were done to assess the effectiveness and safety of oral pafuramidine versus intramuscular pentamidine (the standard treatment), in patients with first stage HAT. The results indicated that, several months after treatment, pafuramidine administered for 10 days was as effective as pentamidine administered for 7 days, and it had a better safety profile than pentamidine. With further study, pafuramidine could be a promising alternative for patients with first stage HAT. In addition, the design of the studies can be used a guide for future studies for identification and delivery of treatment to affected individuals in rural Africa.
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Affiliation(s)
- Christian Burri
- Swiss Tropical and Public Health Institute, Basel, Switzerland
- University of Basel, Basel, Switzerland
| | - Patrick D Yeramian
- The Vaccine and Gene Therapy Institute of Florida, Port St. Lucie, Florida, United States of America
| | - James L Allen
- Immtech Pharmaceuticals, Inc., Vernon Hills, Illinois, United States of America
| | | | | | - Alain Mpanya
- Lisumbi Health Centre, Kinshasa, Democratic Republic of the Congo
| | - Pascal Lutumba
- Institut National de Recherche Biomédicale and Tropical Medicine Department, Kinshasa University, Kinshasa, Democratic Republic of the Congo
| | - Victor Kande Betu Ku Mesu
- Programme des Maladies Tropicales Négligées, Ministère de la Santé Publique Kinshasa, Democratic Republic of the Congo
| | | | | | - Alfred Mpoo Mpoto
- Hôspital Evangélique de Vanga, Vanga, Democratic Republic of the Congo
| | - Mark Thompson
- Federally Qualified Community Health Center, Elgin, Illinois, United States of America
| | | | - Francisco Manuel
- Instituto de Combate e de Controlo das Tripanossomíases, Luanda, Angola
| | | | - Sonja C Bernhard
- Swiss Tropical and Public Health Institute, Basel, Switzerland
- University of Basel, Basel, Switzerland
| | - Carol A Olson
- Infectious Diseases, Global Product Development, PPD, Rockville, Maryland, United States of America
| | - Johannes Blum
- Swiss Tropical and Public Health Institute, Basel, Switzerland
- University of Basel, Basel, Switzerland
| | - Richard R Tidwell
- University of North Carolina, Department of Pathology and Laboratory Medicine, School of Medicine, Chapel Hill, North Carolina, United States of America
| | - Gabriele Pohlig
- Swiss Tropical and Public Health Institute, Basel, Switzerland
- University of Basel, Basel, Switzerland
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7
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Pohlig G, Bernhard SC, Blum J, Burri C, Mpanya A, Lubaki JPF, Mpoto AM, Munungu BF, N’tombe PM, Deo GKM, Mutantu PN, Kuikumbi FM, Mintwo AF, Munungi AK, Dala A, Macharia S, Bilenge CMM, Mesu VKBK, Franco JR, Dituvanga ND, Tidwell RR, Olson CA. Efficacy and Safety of Pafuramidine versus Pentamidine Maleate for Treatment of First Stage Sleeping Sickness in a Randomized, Comparator-Controlled, International Phase 3 Clinical Trial. PLoS Negl Trop Dis 2016; 10:e0004363. [PMID: 26882015 PMCID: PMC4755561 DOI: 10.1371/journal.pntd.0004363] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2015] [Accepted: 12/14/2015] [Indexed: 11/25/2022] Open
Abstract
Background Sleeping sickness (human African trypanosomiasis [HAT]) is a neglected tropical disease with limited treatment options that currently require parenteral administration. In previous studies, orally administered pafuramidine was well tolerated in healthy patients (for up to 21 days) and stage 1 HAT patients (for up to 10 days), and demonstrated efficacy comparable to pentamidine. Methods This was a Phase 3, multi-center, randomized, open-label, parallel-group, active control study where 273 male and female patients with first stage Trypanosoma brucei gambiense HAT were treated at six sites: one trypanosomiasis reference center in Angola, one hospital in South Sudan, and four hospitals in the Democratic Republic of the Congo between August 2005 and September 2009 to support the registration of pafuramidine for treatment of first stage HAT in collaboration with the United States Food and Drug Administration. Patients were treated with either 100 mg of pafuramidine orally twice a day for 10 days or 4 mg/kg pentamidine intramuscularly once daily for 7 days to assess the efficacy and safety of pafuramidine versus pentamidine. Pregnant and lactating women as well as adolescents were included. The primary efficacy endpoint was the combined rate of clinical and parasitological cure at 12 months. The primary safety outcome was the frequency and severity of adverse events. The study was registered on the International Clinical Trials Registry Platform at www.clinicaltrials.gov with the number ISRCTN85534673. Findings/Conclusions The overall cure rate at 12 months was 89% in the pafuramidine group and 95% in the pentamidine group; pafuramidine was non-inferior to pentamidine as the upper bound of the 95% confidence interval did not exceed 15%. The safety profile of pafuramidine was superior to pentamidine; however, 3 patients in the pafuramidine group had glomerulonephritis or nephropathy approximately 8 weeks post-treatment. Two of these events were judged as possibly related to pafuramidine. Despite good tolerability observed in preceding studies, the development program for pafuramidine was discontinued due to delayed post-treatment toxicity. Sleeping sickness, or human African trypanosomiasis (HAT), is a neglected tropical disease. Because only 2 treatment options are available to treat persons with stage 1 disease, and both require parenteral administration, oral drugs would be of great benefit to the affected population. In this Phase 3, multi-center, randomized, open-label, parallel-group study, we compared oral pafuramidine with intramuscular pentamidine in persons in sub-Sahara Africa with first stage HAT. At 12 months, the overall cure rates (combined clinical and parasitological cure) were similar: 89% in the pafuramidine group and 95% in the pentamidine group. At 24 months, the cure rates continued to be high: 84% and 89%, respectively. Pafuramidine’s safety profile was superior to the comparator drug, and it was consistent with the overall safety profile seen in previous Phase 2 studies. Upon further analysis, however, a renal safety issue was identified as being possibly related to pafuramidine and further clinical development was halted. Nevertheless, the clinical studies conducted in the pafuramidine development program provide a model for future studies in rural Africa.
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Affiliation(s)
- Gabriele Pohlig
- Swiss Tropical and Public Health Institute, Pharmaceutical Medicine Unit, Swiss Centre for International Health, Basel, Switzerland
| | - Sonja C. Bernhard
- Swiss Tropical and Public Health Institute, Pharmaceutical Medicine Unit, Swiss Centre for International Health, Basel, Switzerland
- Pharmacy & Clinical Pharmacology at the Division of Clinical Pharmacology, University of Basel, Basel, Switzerland
| | - Johannes Blum
- Swiss Tropical and Public Health Institute, Medical Services and Diagnostic, Basel, Switzerland
| | - Christian Burri
- Pharmacy & Clinical Pharmacology at the Division of Clinical Pharmacology, University of Basel, Basel, Switzerland
- Swiss Tropical and Public Health Institute, Department of Medicines Research, Basel, Switzerland
| | - Alain Mpanya
- Programme Nationale de Lutte contre la Trypanosomiase Humaine Africaine, Kinshasa, Democratic Republic of the Congo
| | | | | | | | | | | | - Pierre Nsele Mutantu
- Institut National de Recherche Biomédicale, Kinshasa, Democratic Republic of the Congo
| | - Florent Mbo Kuikumbi
- Programme Nationale de Lutte contre la Trypanosomiase Humaine Africaine, Kinshasa, Democratic Republic of the Congo
| | | | | | - Amadeu Dala
- Instituto de Combate e de Controlo das Tripanossomíases, Luanda, Angola
| | | | | | - Victor Kande Betu Ku Mesu
- Programme des Maladies Tropicales Négligées, Ministère de la Santé Publique Kinshasa, Democratic Republic of the Congo
| | - Jose Ramon Franco
- World Health Organisation Geneva, Department of Control of Neglected Diseases, Geneva, Switzerland
| | | | - Richard R. Tidwell
- University of North Carolina, Department of Pathology and Lab Medicine, School of Medicine, Chapel Hill, North Carolina, United States of America
- * E-mail:
| | - Carol A. Olson
- Sapphire Oak Consultants, LLC, Lindenhurst, Illinois, United States of America
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Verma SD, Pal N, Singh MK, Sen S. Sequence-Dependent Solvation Dynamics of Minor-Groove Bound Ligand Inside Duplex-DNA. J Phys Chem B 2015; 119:11019-29. [DOI: 10.1021/acs.jpcb.5b01977] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Affiliation(s)
- Sachin Dev Verma
- Spectroscopy Laboratory,
School of Physical Sciences, Jawaharlal Nehru University, New Delhi 110067, India
| | - Nibedita Pal
- Spectroscopy Laboratory,
School of Physical Sciences, Jawaharlal Nehru University, New Delhi 110067, India
| | - Moirangthem Kiran Singh
- Spectroscopy Laboratory,
School of Physical Sciences, Jawaharlal Nehru University, New Delhi 110067, India
| | - Sobhan Sen
- Spectroscopy Laboratory,
School of Physical Sciences, Jawaharlal Nehru University, New Delhi 110067, India
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In vitro and in vivo evaluation of 28DAP010, a novel diamidine for treatment of second-stage African sleeping sickness. Antimicrob Agents Chemother 2014; 58:4452-63. [PMID: 24867978 DOI: 10.1128/aac.02309-13] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
African sleeping sickness is a neglected tropical disease transmitted by tsetse flies. New and better drugs are still needed especially for its second stage, which is fatal if untreated. 28DAP010, a dipyridylbenzene analogue of DB829, is the second simple diamidine found to cure mice with central nervous system infections by a parenteral route of administration. 28DAP010 showed efficacy similar to that of DB829 in dose-response studies in mouse models of first- and second-stage African sleeping sickness. The in vitro time to kill, determined by microcalorimetry, and the parasite clearance time in mice were shorter for 28DAP010 than for DB829. No cross-resistance was observed between 28DAP010 and pentamidine on the tested Trypanosoma brucei gambiense isolates from melarsoprol-refractory patients. 28DAP010 is the second promising preclinical candidate among the diamidines for the treatment of second-stage African sleeping sickness.
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10
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Pfeifer ND, Harris KB, Yan GZ, Brouwer KLR. Determination of intracellular unbound concentrations and subcellular localization of drugs in rat sandwich-cultured hepatocytes compared with liver tissue. Drug Metab Dispos 2013; 41:1949-56. [PMID: 23990525 DOI: 10.1124/dmd.113.052134] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Prediction of clinical efficacy, toxicity, and drug-drug interactions may be improved by accounting for the intracellular unbound drug concentration (C(unbound)) in vitro and in vivo. Furthermore, subcellular drug distribution may aid in predicting efficacy, toxicity, and risk assessment. The present study was designed to quantify the intracellular C(unbound) and subcellular localization of drugs in rat sandwich-cultured hepatocytes (SCH) compared with rat isolated perfused liver (IPL) tissue. Probe drugs with distinct mechanisms of hepatocellular uptake and accumulation were selected for investigation. Following drug treatment, SCH and IPL tissues were homogenized and fractionated by differential centrifugation to enrich for subcellular compartments. Binding in crude lysate and cytosol was determined by equilibrium dialysis; the C(unbound) and intracellular-to-extracellular C(unbound) ratio (K(pu,u)) were used to describe accumulation of unbound drug. Total accumulation (K(pobserved)) in whole tissue was well predicted by the SCH model (within 2- to 3-fold) for the selected drugs. Ritonavir (K(pu,u) ∼1) was evenly distributed among cellular compartments, but highly bound, which explained the observed accumulation within liver tissue. Rosuvastatin was recovered primarily in the cytosolic fraction, but did not exhibit extensive binding, resulting in a K(pu,u) >1 in liver tissue and SCH, consistent with efficient hepatic uptake. Despite extensive binding and sequestration of furamidine within liver tissue, a significant portion of cellular accumulation was attributed to unbound drug (K(pu,u) >16), as expected for a charged, hepatically derived metabolite. Data demonstrate the utility of SCH to predict quantitatively total tissue accumulation and elucidate mechanisms of hepatocellular drug accumulation such as active uptake versus binding/sequestration.
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Affiliation(s)
- Nathan D Pfeifer
- Division of Pharmacotherapy and Experimental Therapeutics, UNC Eshelman School of Pharmacy, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina
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Pharmacokinetics, Trypanosoma brucei gambiense efficacy, and time of drug action of DB829, a preclinical candidate for treatment of second-stage human African trypanosomiasis. Antimicrob Agents Chemother 2013; 57:5330-43. [PMID: 23959303 DOI: 10.1128/aac.00398-13] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Human African trypanosomiasis (HAT, also called sleeping sickness), a neglected tropical disease endemic to sub-Saharan Africa, is caused by the parasites Trypanosoma brucei gambiense and T. brucei rhodesiense. Current drugs against this disease have significant limitations, including toxicity, increasing resistance, and/or a complicated parenteral treatment regimen. DB829 is a novel aza-diamidine that demonstrated excellent efficacy in mice infected with T. b. rhodesiense or T. b. brucei parasites. The current study examined the pharmacokinetics, in vitro and in vivo activity against T. b. gambiense, and time of drug action of DB829 in comparison to pentamidine. DB829 showed outstanding in vivo efficacy in mice infected with parasites of T. b. gambiense strains, despite having higher in vitro 50% inhibitory concentrations (IC50s) than against T. b. rhodesiense strain STIB900. A single dose of DB829 administered intraperitoneally (5 mg/kg of body weight) cured all mice infected with different T. b. gambiense strains. No cross-resistance was observed between DB829 and pentamidine in T. b. gambiense strains isolated from melarsoprol-refractory patients. Compared to pentamidine, DB829 showed a greater systemic exposure when administered intraperitoneally, partially contributing to its improved efficacy. Isothermal microcalorimetry and in vivo time-to-kill studies revealed that DB829 is a slower-acting trypanocidal compound than pentamidine. A single dose of DB829 (20 mg/kg) administered intraperitoneally clears parasites from mouse blood within 2 to 5 days. In summary, DB829 is a promising preclinical candidate for the treatment of first- and second-stage HAT caused by both Trypanosoma brucei subspecies.
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Thuita JK, Wolf KK, Murilla GA, Liu Q, Mutuku JN, Chen Y, Bridges AS, Mdachi RE, Ismail MA, Ching S, Boykin DW, Hall JE, Tidwell RR, Paine MF, Brun R, Wang MZ. Safety, pharmacokinetic, and efficacy studies of oral DB868 in a first stage vervet monkey model of human African trypanosomiasis. PLoS Negl Trop Dis 2013; 7:e2230. [PMID: 23755309 PMCID: PMC3674995 DOI: 10.1371/journal.pntd.0002230] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2013] [Accepted: 04/10/2013] [Indexed: 11/19/2022] Open
Abstract
There are no oral drugs for human African trypanosomiasis (HAT, sleeping sickness). A successful oral drug would have the potential to reduce or eliminate the need for patient hospitalization, thus reducing healthcare costs of HAT. The development of oral medications is a key objective of the Consortium for Parasitic Drug Development (CPDD). In this study, we investigated the safety, pharmacokinetics, and efficacy of a new orally administered CPDD diamidine prodrug, 2,5-bis[5-(N-methoxyamidino)-2-pyridyl]furan (DB868; CPD-007-10), in the vervet monkey model of first stage HAT. DB868 was well tolerated at a dose up to 30 mg/kg/day for 10 days, a cumulative dose of 300 mg/kg. Mean plasma levels of biomarkers indicative of liver injury (alanine aminotransferase, aspartate aminotransferase) were not significantly altered by drug administration. In addition, no kidney-mediated alterations in creatinine and urea concentrations were detected. Pharmacokinetic analysis of plasma confirmed that DB868 was orally available and was converted to the active compound DB829 in both uninfected and infected monkeys. Treatment of infected monkeys with DB868 began 7 days post-infection. In the infected monkeys, DB829 attained a median Cmax (dosing regimen) that was 12-fold (3 mg/kg/day for 7 days), 15-fold (10 mg/kg/day for 7 days), and 31-fold (20 mg/kg/day for 5 days) greater than the IC50 (14 nmol/L) against T. b. rhodesiense STIB900. DB868 cured all infected monkeys, even at the lowest dose tested. In conclusion, oral DB868 cured monkeys with first stage HAT at a cumulative dose 14-fold lower than the maximum tolerated dose and should be considered a lead preclinical candidate in efforts to develop a safe, short course (5–7 days), oral regimen for first stage HAT. Development of orally administered medicines for human African trypanosomiasis (HAT) would potentially reduce the need for patient hospitalization, thus lowering healthcare costs. In this study, we investigated the potential of a novel diamidine prodrug, DB868 (CPD-007-10), as an oral treatment for first stage HAT. When administered to uninfected monkeys by oral gavage, DB868 was well tolerated up to a maximum dose of 30 mg/kg/day for 10 days (cumulative dose [CD] = 300 mg/kg). DB868 was absorbed into the systemic circulation and was converted to the active compound DB829 in concentrations that were potentially therapeutic for blood trypanosomes. Subsequently, DB868 was evaluated for efficacy in the first stage vervet monkey model of HAT in which treatment was initiated at 7 days post-infection with T. b. rhodesiense KETRI 2537. All infected monkeys were cured, even at the lowest of the three dose regimens tested: 3 mg/kg/day for 7 days (CD = 21 mg/kg), 10 mg/kg/day for 7 days (CD = 70 mg/kg) and 20 mg/kg/day for 5 days (CD = 100 mg/kg). DB868 conversion to DB829 was comparable between uninfected and infected monkeys. In view of its favourable safety and oral efficacy profile, we conclude that DB868 is a suitable candidate for development as a new treatment for first stage HAT.
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Affiliation(s)
- John K. Thuita
- Trypanosomiasis Research Centre, Kenya Agricultural Research Institute (KARI-TRC), Kikuyu, Kenya
- University of Basel, Basel, Switzerland
| | - Kristina K. Wolf
- UNC Eshelman School of Pharmacy, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America
| | - Grace A. Murilla
- Trypanosomiasis Research Centre, Kenya Agricultural Research Institute (KARI-TRC), Kikuyu, Kenya
| | - Qiang Liu
- UNC Eshelman School of Pharmacy, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America
| | - James N. Mutuku
- Trypanosomiasis Research Centre, Kenya Agricultural Research Institute (KARI-TRC), Kikuyu, Kenya
| | - Yao Chen
- Department of Pharmaceutical Chemistry, The University of Kansas, Lawrence, Kansas, United States of America
| | - Arlene S. Bridges
- Department of Pathology and Laboratory Medicine, School of Medicine, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America
| | - Raymond E. Mdachi
- Trypanosomiasis Research Centre, Kenya Agricultural Research Institute (KARI-TRC), Kikuyu, Kenya
| | - Mohamed A. Ismail
- Department of Chemistry, Georgia State University, Atlanta, Georgia, United States of America
| | - Shelley Ching
- SVC Associates, Inc., Apex, North Carolina, United States of America
| | - David W. Boykin
- Department of Chemistry, Georgia State University, Atlanta, Georgia, United States of America
| | - James Edwin Hall
- Department of Pathology and Laboratory Medicine, School of Medicine, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America
| | - Richard R. Tidwell
- Department of Pathology and Laboratory Medicine, School of Medicine, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America
| | - Mary F. Paine
- UNC Eshelman School of Pharmacy, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America
| | - Reto Brun
- University of Basel, Basel, Switzerland
- Swiss Tropical and Public Health Institute, Basel, Switzerland
| | - Michael Zhuo Wang
- Department of Pharmaceutical Chemistry, The University of Kansas, Lawrence, Kansas, United States of America
- * E-mail:
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Novel amidines and analogues as promising agents against intracellular parasites: a systematic review. Parasitology 2013; 140:929-51. [PMID: 23561006 DOI: 10.1017/s0031182013000292] [Citation(s) in RCA: 84] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Parasitic protozoa comprise diverse aetiological agents responsible for important diseases in humans and animals including sleeping sickness, Chagas disease, leishmaniasis, malaria, toxoplasmosis and others. They are major causes of mortality and morbidity in tropical and subtropical countries, and are also responsible for important economic losses. However, up to now, for most of these parasitic diseases, effective vaccines are lacking and the approved chemotherapeutic compounds present high toxicity, increasing resistance, limited efficacy and require long periods of treatment. Many of these parasitic illnesses predominantly affect low-income populations of developing countries for which new pharmaceutical alternatives are urgently needed. Thus, very low research funding is available. Amidine-containing compounds such as pentamidine are DNA minor groove binders with a broad spectrum of activities against human and veterinary pathogens. Due to their promising microbicidal activity but their rather poor bioavailability and high toxicity, many analogues and derivatives, including pro-drugs, have been synthesized and screened in vitro and in vivo in order to improve their selectivity and pharmacological properties. This review summarizes the knowledge on amidines and analogues with respect to their synthesis, pharmacological profile, mechanistic and biological effects upon a range of intracellular protozoan parasites. The bulk of these data may contribute to the future design and structure optimization of new aromatic dicationic compounds as novel antiparasitic drug candidates.
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Thuita JK, Wang MZ, Kagira JM, Denton CL, Paine MF, Mdachi RE, Murilla GA, Ching S, Boykin DW, Tidwell RR, Hall JE, Brun R. Pharmacology of DB844, an orally active aza analogue of pafuramidine, in a monkey model of second stage human African trypanosomiasis. PLoS Negl Trop Dis 2012; 6:e1734. [PMID: 22848769 PMCID: PMC3404106 DOI: 10.1371/journal.pntd.0001734] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2012] [Accepted: 06/04/2012] [Indexed: 11/18/2022] Open
Abstract
Novel drugs to treat human African trypanosomiasis (HAT) are still urgently needed despite the recent addition of nifurtimox-eflornithine combination therapy (NECT) to WHO Model Lists of Essential Medicines against second stage HAT, where parasites have invaded the central nervous system (CNS). The pharmacology of a potential orally available lead compound, N-methoxy-6-{5-[4-(N-methoxyamidino) phenyl]-furan-2-yl}-nicotinamidine (DB844), was evaluated in a vervet monkey model of second stage HAT, following promising results in mice. DB844 was administered orally to vervet monkeys, beginning 28 days post infection (DPI) with Trypanosoma brucei rhodesiense KETRI 2537. DB844 was absorbed and converted to the active metabolite 6-[5-(4-phenylamidinophenyl)-furanyl-2-yl]-nicotinamide (DB820), exhibiting plasma C(max) values of 430 and 190 nM for DB844 and DB820, respectively, after the 14th dose at 6 mg/kg qd. A 100-fold reduction in blood trypanosome counts was observed within 24 h of the third dose and, at the end of treatment evaluation performed four days post the last drug dose, trypanosomes were not detected in the blood or cerebrospinal fluid of any monkey. However, some animals relapsed during the 300 days of post treatment monitoring, resulting in a cure rate of 3/8 (37.5%) and 3/7 (42.9%) for the 5 mg/kg×10 days and the 6 mg/kg×14 days dose regimens respectively. These DB844 efficacy data were an improvement compared with pentamidine and pafuramidine both of which were previously shown to be non-curative in this model of CNS stage HAT. These data show that synthesis of novel diamidines with improved activity against CNS-stage HAT was possible.
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Affiliation(s)
- John K. Thuita
- Trypanosomiasis Research Centre, Kenya Agricultural Research Institute (TRC-KARI), Kikuyu, Kenya
| | - Michael Z. Wang
- Department of Pharmaceutical Chemistry, University of Kansas, Lawrence, Kansas, United States of America
| | - John M. Kagira
- Trypanosomiasis Research Centre, Kenya Agricultural Research Institute (TRC-KARI), Kikuyu, Kenya
| | - Cathrine L. Denton
- Eshelman School of Pharmacy, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America
| | - Mary F. Paine
- Eshelman School of Pharmacy, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America
| | - Raymond E. Mdachi
- Trypanosomiasis Research Centre, Kenya Agricultural Research Institute (TRC-KARI), Kikuyu, Kenya
| | - Grace A. Murilla
- Trypanosomiasis Research Centre, Kenya Agricultural Research Institute (TRC-KARI), Kikuyu, Kenya
| | - Shelley Ching
- SVC Associates, Inc., Apex, North Carolina, United States of America
| | - David W. Boykin
- Chemistry Department, Georgia State University, Atlanta, Georgia, United States of America
| | - Richard R. Tidwell
- Pathology Department, School of Medicine, University of North Carolina at Chapel Hill, North Carolina, United States of America
| | - James E. Hall
- Pathology Department, School of Medicine, University of North Carolina at Chapel Hill, North Carolina, United States of America
| | - Reto Brun
- Swiss Tropical and Public Health Institute and University of Basel, Basel, Switzerland
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15
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Bordello J, Sánchez MI, Vázquez ME, Mascareñas JL, Al-Soufi W, Novo M. Single-Molecule Approach to DNA Minor-Groove Association Dynamics. Angew Chem Int Ed Engl 2012. [DOI: 10.1002/ange.201201099] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
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16
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Bordello J, Sánchez MI, Vázquez ME, Mascareñas JL, Al-Soufi W, Novo M. Single-molecule approach to DNA minor-groove association dynamics. Angew Chem Int Ed Engl 2012; 51:7541-4. [PMID: 22700034 DOI: 10.1002/anie.201201099] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2012] [Revised: 03/26/2012] [Indexed: 11/09/2022]
Affiliation(s)
- Jorge Bordello
- Departamento de Química Física, Universidade de Santiago de Compostela, Facultade de Ciencias, 27001 Lugo, Spain
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17
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Yan GZ, Generaux CN, Yoon M, Goldsmith RB, Tidwell RR, Hall JE, Olson CA, Clewell HJ, Brouwer KLR, Paine MF. A semiphysiologically based pharmacokinetic modeling approach to predict the dose-exposure relationship of an antiparasitic prodrug/active metabolite pair. Drug Metab Dispos 2011; 40:6-17. [PMID: 21953913 DOI: 10.1124/dmd.111.040063] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
Dose selection during antiparasitic drug development in animal models and humans traditionally has relied on correlations between plasma concentrations obtained at or below maximally tolerated doses that are efficacious. The objective of this study was to improve the understanding of the relationship between dose and plasma/tissue exposure of the model antiparasitic agent, pafuramidine, using a semiphysiologically based pharmacokinetic (semi-PBPK) modeling approach. Preclinical and clinical data generated during the development of pafuramidine, a prodrug of the active metabolite, furamidine, were used. A whole-body semi-PBPK model for rats was developed based on a whole-liver PBPK model using rat isolated perfused liver data. A whole-body semi-PBPK model for humans was developed on the basis of the whole-body rat model. Scaling factors were calculated using metabolic and transport clearance data generated from rat and human sandwich-cultured hepatocytes. Both whole-body models described pafuramidine and furamidine disposition in plasma and predicted furamidine tissue (liver and kidney) exposure and excretion profiles (biliary and renal). The whole-body models predicted that the intestine contributes significantly (30-40%) to presystemic furamidine formation in both rats and humans. The predicted terminal elimination half-life of furamidine in plasma was 3- to 4-fold longer than that of pafuramidine in rats (170 versus 47 h) and humans (64 versus 19 h). The dose-plasma/tissue exposure relationship for the prodrug/active metabolite pair was determined using the whole-body models. The human model proposed a dose regimen of pafuramidine (40 mg once daily) based on a predefined efficacy-safety index. A similar approach could be used to guide dose-ranging studies in humans for next-in-class compounds.
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Affiliation(s)
- Grace Zhixia Yan
- Division of Pharmacotherapy and Experimental Therapeutics, UNC Eshelman School of Pharmacy, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599-7569, USA
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18
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Brun R, Don R, Jacobs RT, Wang MZ, Barrett MP. Development of novel drugs for human African trypanosomiasis. Future Microbiol 2011; 6:677-91. [DOI: 10.2217/fmb.11.44] [Citation(s) in RCA: 108] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Human African trypanosomiasis (HAT) or ‘sleeping sickness’ is a neglected tropical disease caused by the parasite Trypanosoma brucei. Novel models for funding pharmaceutical development against HAT are beginning to yield results. The Drugs for Neglected Diseases initiative (DNDi) rediscovered a nitroimidazole, fexinidazole, which is currently in Phase I clinical trials. Novel benzoxaboroles, discovered by Anacor, Scynexis and DNDi, have good pharmacokinetic properties in plasma and in the brain and are curative in a murine model of stage two HAT with brain infection. The Consortium for Parasitic Drug Development (CPDD) has identified a series of dicationic compounds that can cure a monkey model of stage two HAT. With other screening programs yielding hits, the pipeline for new HAT drugs might finally begin to fill.
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Affiliation(s)
- Reto Brun
- Department Medical Parasitology & Infection Biology, Swiss Tropical & Public Health Institute, and, University of Basel, CH-4002 Basel, Switzerland
| | - Robert Don
- Drugs for Neglected Diseases initiative, Geneva, Switzerland
| | - Robert T Jacobs
- Department of Chemistry, SCYNEXIS, Inc., PO Box 12878, Research Triangle Park, NC, 27709-2878, USA
| | - Michael Zhuo Wang
- Eshelman School of Pharmacy, University of North Carolina, Chapel Hill, NC, USA
| | - Michael P Barrett
- Wellcome Trust Centre for Molecular Parasitology, University of Glasgow, Glasgow, Scotland
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19
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Yan GZ, Brouwer KLR, Pollack GM, Wang MZ, Tidwell RR, Hall JE, Paine MF. Mechanisms underlying differences in systemic exposure of structurally similar active metabolites: comparison of two preclinical hepatic models. J Pharmacol Exp Ther 2011; 337:503-12. [PMID: 21320872 DOI: 10.1124/jpet.110.177220] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Selection of in vitro models that accurately characterize metabolite systemic and hepatobiliary exposure remains a challenge in drug development. In the present study, mechanisms underlying differences in systemic exposure of two active metabolites, furamidine and 2,5-bis (5-amidino)-2-pyridyl furan (CPD-0801), were examined using two hepatic models from rats: isolated perfused livers (IPLs) and sandwich-cultured hepatocytes (SCH). Pafuramidine, a prodrug of furamidine, and 2,5-bis [5-(N-methoxyamidino)-2-pyridyl] furan (CPD-0868), a prodrug of CPD-0801, were selected for investigation because CPD-0801 exhibits greater systemic exposure than furamidine, despite remarkable structural similarity between these two active metabolites. In both IPLs and SCH, the extent of conversion of CPD-0868 to CPD-0801 was consistently higher than that of pafuramidine to furamidine over time (at most 2.5-fold); area under the curve (AUC) of CPD-0801 in IPL perfusate and SCH medium was at least 7-fold higher than that of furamidine. Pharmacokinetic modeling revealed that the rate constant for basolateral (liver to blood) net efflux (k(A_net efflux)) of total formed CPD-0801 (bound + unbound) was 6-fold higher than that of furamidine. Hepatic accumulation of both active metabolites was extensive (>95% of total formed); the hepatic unbound fraction (f(u,L)) of CPD-0801 was 5-fold higher than that of furamidine (1.6 versus 0.3%). Incorporation of f(u,L) into the pharmacokinetic model resulted in comparable k(A_net efflux,u) between furamidine and CPD-0801. In conclusion, intrahepatic binding markedly influenced the disposition of these active metabolites. A higher f(u,L) explained, in part, the enhanced perfusate AUC of CPD-0801 compared with furamidine in IPLs. SCH predicted the disposition of prodrug/metabolite in IPLs.
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Affiliation(s)
- Grace Zhixia Yan
- Division of Pharmacotherapy and Experimental Therapeutics, UNC Eshelman School of Pharmacy, University of North Carolina, Chapel Hill, NC 27599-7569, USA
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20
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Sun J, Miller JM, Beig A, Rozen L, Amidon GL, Dahan A. Mechanistic enhancement of the intestinal absorption of drugs containing the polar guanidino functionality. Expert Opin Drug Metab Toxicol 2011; 7:313-23. [DOI: 10.1517/17425255.2011.550875] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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22
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Margout D, Gattacceca F, Moarbess G, Wein S, Ba CTV, Le Pape S, Berger O, Escale R, Vial HJ, Bressolle FM. Pharmacokinetic properties and metabolism of a new potent antimalarial N-alkylamidine compound, M64, and its corresponding bioprecursors. Eur J Pharm Sci 2011; 42:81-90. [DOI: 10.1016/j.ejps.2010.10.012] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2010] [Accepted: 10/23/2010] [Indexed: 11/29/2022]
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Goldsmith RB, Gray DR, Yan Z, Generaux CN, Tidwell RR, Reisner HM. Application of monoclonal antibodies to measure metabolism of an anti-trypanosomal compound in vitro and in vivo. J Clin Lab Anal 2010; 24:187-94. [PMID: 20486201 PMCID: PMC6647651 DOI: 10.1002/jcla.20380] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Human African trypanosomiasis (HAT), also called African sleeping sickness, is a neglected tropical parasitic disease indigenous to sub-Saharan Africa. Diamidine compounds, including pentamidine and CPD-0801, are potent anti-trypanosomal molecules. The latter is a potential drug in the development at the UNC based Consortium for Parasitic Drug Development. An orally bioavailable prodrug of CPD-0801, DB868, is metabolized primarily in the liver to the active form. A monoclonal antibody developed against a pentamidine derivative has shown significant reactivity with CPD-0801 (EC(50) 65.1 nM), but not with the prodrug (EC(50)>18,000 nM). An inhibitory enzyme-linked immunosorbent assay (IELISA) has been used to quantitatively monitor prodrug metabolism by detecting the production of the active compound over time in a sandwich culture rat hepatocyte system and in rats. These results were compared with the results of the standard LC/MS/MS assay. Spearman coefficients of 0.96 and 0.933 (in vitro and in vivo, respectively) indicate a high correlation between these two measurement methods. This novel IELISA provides a facile, inexpensive, and accurate method for drug detection that may aide in elucidating the mechanisms of action and toxicity of existing and future diamidine compounds.
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Affiliation(s)
- Rachel Beaulieu Goldsmith
- Department of Pathology and Laboratory Medicine, School of Medicine, University of North Carolina, Chapel Hill, North Carolina
| | - Danny R. Gray
- Center for Delivery of Molecules and Cells, Department of Biomedical Engineering, Case Western Reserve, Cleveland, Ohio
| | - Zhixia Yan
- Eshelman School of Pharmacy, University of North Carolina, Chapel Hill, North Carolina
| | - Claudia N. Generaux
- Eshelman School of Pharmacy, University of North Carolina, Chapel Hill, North Carolina
| | - Richard R. Tidwell
- Department of Pathology and Laboratory Medicine, School of Medicine, University of North Carolina, Chapel Hill, North Carolina
| | - Howard M. Reisner
- Department of Pathology and Laboratory Medicine, School of Medicine, University of North Carolina, Chapel Hill, North Carolina
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24
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In vitro activity and preliminary toxicity of various diamidine compounds against Trypanosoma evansi. Vet Parasitol 2010; 169:264-72. [DOI: 10.1016/j.vetpar.2010.01.019] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2009] [Revised: 01/07/2010] [Accepted: 01/14/2010] [Indexed: 11/23/2022]
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25
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Microdosing: a valuable tool for accelerating drug development and the role of bioanalytical methods in meeting the challenge. Bioanalysis 2009; 1:1293-305. [DOI: 10.4155/bio.09.107] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
The concept of specifically determining the clinical pharmacokinetics of a compound using a very low nonpharmacologically active dose (microdose) with an abridged safety and chemistry, manufacturing and control package is relatively new. It is not without its controversy and it is still a subject of discussion. Here, the rationale and application of this approach are examined, together with the regulatory and bioanalytical framework. There are two bioanalytical methods commonly used for human microdosing studies: LC–MS/MS and accelerator MS (AMS). Each method has advantages and disadvantages with the choice of instrumentation being closely tied to the primary objective(s) of the study. If a rapid decision is required on the appropriateness of a pharmacokinetic profile or if a choice is needed from a series of compounds, especially before radiolabeled material is available, LC–MS/MS may be preferable. However, if extreme sensitivity is required, data are required on all drug-related material and metabolites, or a simultaneous intravenous microdose is used to determine absolute bioavailability (sometimes referred to as microtracing), AMS becomes the analytical method of choice. Examples are provided of microdosing studies utilizing both of these bioanalytical techniques. It is emphasized that microdosing is only one tool in the drug developer’s tool box and it should be used in the context of all available data. However, when used appropriately, microdosing is a valuable tool, bridging between lead optimization and early clinical development.
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Testa B. Prodrugs: bridging pharmacodynamic/pharmacokinetic gaps. Curr Opin Chem Biol 2009; 13:338-44. [PMID: 19473869 DOI: 10.1016/j.cbpa.2009.04.620] [Citation(s) in RCA: 66] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2009] [Revised: 04/20/2009] [Accepted: 04/21/2009] [Indexed: 12/31/2022]
Abstract
In this mini review, prodrugs are discussed with a focus on their pharmaceutical, pharmacokinetic, and pharmacodynamic objectives, as well as on the resulting therapeutic benefits. Carrier-linked prodrugs remain the most extensively investigated and receive due attention here with recent successes highlighted. A clear trend is apparent in modern prodrug research, namely the increased attention given to the knowledge-based design of bioprecursors, namely prodrugs devoid of a detachable promoiety. In most cases, such prodrugs are activated by in situ reduction, hence their designation as bioreductive prodrugs. This is a particularly active field in the design of more selective, small-molecule antitumor agents. New antimicrobial agents are also in the pipeline. In addition, biooxidative bioprecursors offer a promising strategy in specific cases, as illustrated by the successful antiaggregating agent clopidogrel.
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Affiliation(s)
- Bernard Testa
- Pharmacy Department, University Hospital Centre, CHUV/BH-04, 46 Rue du Bugnon, CH-1011 Lausanne, Switzerland.
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27
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Nguyen B, Neidle S, Wilson WD. A role for water molecules in DNA-ligand minor groove recognition. Acc Chem Res 2009; 42:11-21. [PMID: 18798655 DOI: 10.1021/ar800016q] [Citation(s) in RCA: 100] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Targeting the minor groove of DNA through binding to a small molecule has long been considered an important molecular-recognition strategy in biology. A wide range of synthetic heterocyclic molecules bind noncovalently in the minor groove of the double helix and are also effective against a number of human and animal diseases. A classic structural concept, the isohelicity principle, has guided much of this work: such heterocyclic molecules require a shape that complements the convex surface of the minor groove. Researchers have used this principle to design molecules that can read DNA sequences. This principle also predicts that molecules that lack the complementary shape requirement would only bind weakly to DNA. Recently, however, researchers have unexpectedly found that some essentially linear compounds, which do not have this feature, can have high DNA affinity. In this Account, we discuss an alternative recognition concept based on these new findings. We demonstrate that highly structured water molecules can play a key role in mediating between the ligand and DNA minor groove without loss of binding affinity. Combined structural and thermodynamic approaches to understanding the behavior of these molecules have shown that there are different categories of bound water in their DNA complexes. For example, application of this water-bridging concept to the phenylamidine platform has resulted in the discovery of molecules with high levels of biological activity and low nonspecific toxicity. Some of these molecules are now in advanced clinical trials.
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Affiliation(s)
- Binh Nguyen
- Department of Chemistry, Georgia State University, Atlanta, Georgia 30302
| | - Stephen Neidle
- CRUK Biomolecular Structure Group, The School of Pharmacy, University of London, London WC1N 1AX, U.K
| | - W. David Wilson
- Department of Chemistry, Georgia State University, Atlanta, Georgia 30302
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28
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Soeiro MNC, de Castro SL. Trypanosoma cruzitargets for new chemotherapeutic approaches. Expert Opin Ther Targets 2008; 13:105-21. [DOI: 10.1517/14728220802623881] [Citation(s) in RCA: 103] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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29
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Ming X, Ju W, Wu H, Tidwell RR, Hall JE, Thakker DR. Transport of dicationic drugs pentamidine and furamidine by human organic cation transporters. Drug Metab Dispos 2008; 37:424-30. [PMID: 18971316 DOI: 10.1124/dmd.108.024083] [Citation(s) in RCA: 70] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
The antiparasitic activity of aromatic diamidine drugs, pentamidine and furamidine, depends on their entry into the pathogenic protozoa via membrane transporters. However, no such diamidine transporter has been identified in mammalian cells. The goal of this study is to investigate whether these dicationic drugs are substrates for human organic cation transporters (hOCTs, solute carrier family 22A1-3) and whether hOCTs play a role in their tissue distribution, elimination, and toxicity. Inhibitory and substrate activities of pentamidine and furamidine were studied in stably transfected Chinese hamster ovary (CHO) cells. The results of [(3)H]1-methyl-4-phenylpyridinium uptake study showed that pentamidine is a potent inhibitor for all three OCT isoforms (IC50 < 20 microM), whereas furamidine is a potent inhibitor for hOCT1 and hOCT3 (IC50 < 21 microM) but a less potent inhibitor for hOCT2 (IC50 = 189.2 microM). Both diamidines are good substrates for hOCT1 (Km = 36.4 and 6.1 microM, respectively), but neither is a substrate for hOCT2 or hOCT3. The cytotoxicity of pentamidine and furamidine was 4.4- and 9.3-fold greater, respectively, in CHO-hOCT1 cells compared with the mock cells. Ranitidine, an hOCT1 inhibitor, reversed this hOCT1-mediated potentiation of cytotoxicity. This is the first finding that dicationic drugs, such as pentamidine and furamidine, are substrates for hOCT1. In humans, aromatic diamidines are primarily eliminated in the bile but are distributed and cause toxicity in both liver and kidney. These transporters may play important roles in the disposition of aromatic diamidines in humans, as well as resultant drug-drug interactions and toxicity involving diamidine drugs.
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Affiliation(s)
- Xin Ming
- Division of Molecular Pharmaceutics, Eshelman School of Pharmacy, 3309 Kerr Hall, CB 7360, the University of North Carolina at Chapel Hill, Chapel Hill, NC 27599-7360, USA
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Safety evaluation to support First-In-Man investigations I: Kinetic and safety pharmacology studies. Regul Toxicol Pharmacol 2008; 51:230-6. [DOI: 10.1016/j.yrtph.2008.04.007] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2008] [Accepted: 04/11/2008] [Indexed: 11/18/2022]
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Yanow SK, Purcell LA, Lee M, Spithill TW. Genomics-based drug design targets the AT-rich malaria parasite: implications for antiparasite chemotherapy. Pharmacogenomics 2008; 8:1267-72. [PMID: 17924840 DOI: 10.2217/14622416.8.9.1267] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Evaluation of: Woynarowski JM, Krugliak M, Ginsburg H: Pharmacogenomic analyses of targeting the AT-rich malaria parasite genome with AT-specific alkylating drugs. Mol. Biochem. Parasitol. 154(1), 70-81 (2007) [1] . The sequencing of the malaria genome sought to expose the parasite's ability to cause disease and identify new targets for antimalarial drugs and vaccines. In this study, the authors discovered how malaria genomic DNA, which is unusually rich in adenine and thymine nucleotides, is intrinsically a target for a selective class of compounds. AT-specific DNA-binding agents have previously been shown to have potent antimalarial activity in vitro. The authors used high-resolution bioinformatic tools to explore the genomic basis for this drug susceptibility, first at the level of individual DNA-binding sites, then expanding to the entire genomic context of each malaria chromosome. Their findings revealed a nonrandom distribution and organization of drug-binding sites that can be further exploited to target these AT sequences. Based on these findings, comparative bioinformatics analyses with other parasite genomes may lead to the identification of new target organisms for these AT-specific drugs and have wide implications for the treatment of human and animal parasitic diseases.
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Affiliation(s)
- Stephanie K Yanow
- Provincial Laboratory for Public Health, WMC Rm 2B4.59, 8440 112th Street, Edmonton, AB, Canada.
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Chen D, Marsh R, Aberg JA. Pafuramidine for Pneumocystis jiroveci pneumonia in HIV-infected individuals. Expert Rev Anti Infect Ther 2008; 5:921-8. [PMID: 18039076 DOI: 10.1586/14787210.5.6.921] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Pneumocystis jiroveci pneumonia remains one of the major worldwide contributors to the morbidity and mortality of those with HIV infection. The mainstay of therapy for treatment is trimethoprim-sulfamethoxazole (TMP-SMX); however TMP-SMX may be associated with significant side effects and intolerability. In addition, TMP-SMX has a moderate pill burden with three- to four-times daily dosing schedule. Patients unable to tolerate TMP-SMX are confronted with either parenteral therapy or other oral agents that may be less efficacious or are associated with potential serious adverse reactions. Pafuramidine (DB289) is an orally bioavailable prodrug of furamidine (DB75), an investigational diamidine that is less toxic than previous diamidines such as pentamidine. To date, human trials suggest that pafuramidine is well tolerated overall and has clinical activity against Pneumocystis pneumonia. In this article, we review the available data for the use of pafuramidine in Pneumocystis pneumonia.
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Affiliation(s)
- Donald Chen
- New York University, Department of Medicine, Division of Infectious Disease, AIDS Clinical Trials Unit, Bellevue C and D Building, Room 558, 550 First Avenue, New York, NY 10016-6481, USA
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Liu Y, Kumar A, Boykin DW, Wilson WD. Sequence and length dependent thermodynamic differences in heterocyclic diamidine interactions at AT base pairs in the DNA minor groove. Biophys Chem 2007; 131:1-14. [PMID: 17889984 PMCID: PMC2291445 DOI: 10.1016/j.bpc.2007.08.007] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2007] [Revised: 08/22/2007] [Accepted: 08/23/2007] [Indexed: 11/17/2022]
Abstract
With the goal of developing a better understanding of the antiparasitic biological action of DB75, we have evaluated its interaction with duplex alternating and nonalternating sequence AT polymers and oligomers. These DNAs provide an important pair of sequences in a detailed thermodynamic analysis of variations in interaction of DB75 with AT sites. The results for DB75 binding to the alternating and nonalternating AT sequences are quite different at the fundamental thermodynamic level. Although the Gibbs energies are similar, the enthalpies for DB75 binding with poly(dA).poly(dT) and poly(dA-dT).poly(dA-dT) are +3.1 and -4.5 kcal/mol, respectively, while the binding entropies are 41.7 and 15.2 cal/mol.K, respectively. The underlying thermodynamics of binding to AT sites in the minor groove plays a key role in the recognition process. It was also observed that DB75 binding with poly(dA).poly(dT) can induce T.A.T triplet formation and the compound binds strongly to the dT.dA.dT triplex.
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Affiliation(s)
| | | | | | - W. David Wilson
- *Corresponding author : W. David Wilson, Department of Chemistry, Georgia State University, Atlanta, GA 30302-4098, USA, Tel: +1-404-413-5503, Fax: +1-404-413-5505,
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Wang MZ, Wu JQ, Bridges AS, Zeldin DC, Kornbluth S, Tidwell RR, Hall JE, Paine MF. Human enteric microsomal CYP4F enzymes O-demethylate the antiparasitic prodrug pafuramidine. Drug Metab Dispos 2007; 35:2067-75. [PMID: 17709372 PMCID: PMC2364724 DOI: 10.1124/dmd.107.016428] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
CYP4F enzymes, including CYP4F2 and CYP4F3B, were recently shown to be the major enzymes catalyzing the initial oxidative O-demethylation of the antiparasitic prodrug pafuramidine (DB289) by human liver microsomes. As suggested by a low oral bioavailability, DB289 could undergo first-pass biotransformation in the intestine, as well as in the liver. Using human intestinal microsomes (HIM), we characterized the enteric enzymes that catalyze the initial O-demethylation of DB289 to the intermediate metabolite, M1. M1 formation in HIM was catalyzed by cytochrome P450 (P450) enzymes, as evidenced by potent inhibition by 1-aminobenzotriazole and the requirement for NADPH. Apparent K(m) and V(max) values ranged from 0.6 to 2.4 microM and from 0.02 to 0.89 nmol/min/mg protein, respectively (n = 9). Of the P450 chemical inhibitors evaluated, ketoconazole was the most potent, inhibiting M1 formation by 66%. Two inhibitors of P450-mediated arachidonic acid metabolism, HET0016 (N-hydroxy-N'-(4-n-butyl-2-methylphenyl)formamidine) and 17-octadecynoic acid, inhibited M1 formation in a concentration-dependent manner (up to 95%). Immunoinhibition with an antibody raised against CYP4F2 showed concentration-dependent inhibition of M1 formation (up to 92%), whereas antibodies against CYP3A4/5 and CYP2J2 had negligible to modest effects. M1 formation rates correlated strongly with arachidonic acid omega-hydroxylation rates (r(2) = 0.94, P < 0.0001, n = 12) in a panel of HIM that lacked detectable CYP4A11 protein expression. Quantitative Western blot analysis revealed appreciable CYP4F expression in these HIM, with a mean (range) of 7 (3-18) pmol/mg protein. We conclude that enteric CYP4F enzymes could play a role in the first-pass biotransformation of DB289 and other xenobiotics.
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Affiliation(s)
- Michael Zhuo Wang
- School of Pharmacy, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
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Soeiro MDNC, Souza EMD, Boykin DW. Antiparasitic activity of aromatic diamidines and their patented literature. Expert Opin Ther Pat 2007. [DOI: 10.1517/13543776.17.8.927] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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Wang MZ, Saulter JY, Usuki E, Cheung YL, Hall M, Bridges AS, Loewen G, Parkinson OT, Stephens CE, Allen JL, Zeldin DC, Boykin DW, Tidwell RR, Parkinson A, Paine MF, Hall JE. CYP4F enzymes are the major enzymes in human liver microsomes that catalyze the O-demethylation of the antiparasitic prodrug DB289 [2,5-bis(4-amidinophenyl)furan-bis-O-methylamidoxime]. Drug Metab Dispos 2006; 34:1985-94. [PMID: 16997912 PMCID: PMC2077835 DOI: 10.1124/dmd.106.010587] [Citation(s) in RCA: 68] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
DB289 [2,5-bis(4-amidinophenyl)furan-bis-O-methylamidoxime] is biotransformed to the potent antiparasitic diamidine DB75 [2,5-bis(4-amidinophenyl) furan] by sequential oxidative O-demethylation and reductive N-dehydroxylation reactions. Previous work demonstrated that the N-dehydroxylation reactions are catalyzed by cytochrome b5/NADH-cytochrome b5 reductase. Enzymes responsible for catalyzing the DB289 O-demethylation pathway have not been identified. We report an in vitro metabolism study to characterize enzymes in human liver microsomes (HLMs) that catalyze the initial O-demethylation of DB289 (M1 formation). Potent inhibition by 1-aminobenzotriazole confirmed that M1 formation is catalyzed by P450 enzymes. M1 formation by HLMs was NADPH-dependent, with a Km and Vmax of 0.5 microM and 3.8 nmol/min/mg protein, respectively. Initial screening showed that recombinant CYP1A1, CYP1A2, and CYP1B1 were efficient catalysts of M1 formation. However, none of these three enzymes was responsible for M1 formation by HLMs. Further screening showed that recombinant CYP2J2, CYP4F2, and CYP4F3B could also catalyze M1 formation. An antibody against CYP4F2, which inhibited both CYP4F2 and CYP4F3B, inhibited 91% of M1 formation by HLMs. Two inhibitors of P450-mediated arachidonic acid metabolism, HET0016 (N-hydroxy-N'-(4-n-butyl-2-methylphenyl)formamidine) and 17-octadecynoic acid, effectively inhibited M1 formation by HLMs. Inhibition studies with ebastine and antibodies against CYP2J2 suggested that CYP2J2 was not involved in M1 formation by HLMs. Additionally, ketoconazole preferentially inhibited CYP4F2, but not CYP4F3B, and partially inhibited M1 formation by HLMs. We conclude that CYP4F enzymes (e.g., CYP4F2, CYP4F3B) are the major enzymes responsible for M1 formation by HLMs. These findings indicate that, in human liver, members of the CYP4F subfamily biotransform not only endogenous compounds but also xenobiotics.
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Affiliation(s)
- Michael Zhuo Wang
- Division of Molecular Pharmaceutics, School of Pharmacy, The University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
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