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Abstract
The number of gene therapies in development continues to increase, as they represent a novel method to treat, and potentially cure, many diseases. Gene therapies can be conducted with an in vivo or ex vivo approach, to cause gene augmentation, gene suppression, or genomic editing. Adeno-associated viruses are commonly used to deliver gene therapies, but their use is associated with several manufacturing, nonclinical and clinical challenges. As these challenges emerge, regulatory agency expectations continue to evolve. Following administration of rAAV-based gene therapies, nonclinical toxicities may occur, which includes immunogenicity, hepatotoxicity, neurotoxicity, and the potential risks for insertional mutagenesis and subsequent tumorgenicity. The mechanism for these findings and translation into the clinical setting are unclear at this time but have influenced the nonclinical studies that regulatory agencies are increasingly requesting to support clinical trials and marketing authorizations. These evolving regulatory expectations and toxicities, as well as future nonclinical considerations, are discussed herein.
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Affiliation(s)
- Michael W Bolt
- Pfizer Inc., Drug Safety Research and Development, Cambridge, MA, USA
| | - Joseph T Brady
- Pfizer Inc., Drug Safety Research and Development, Cambridge, MA, USA
| | | | - K Nasir Khan
- Pfizer Inc., Drug Safety Research and Development, Groton, CA, USA
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van der Laan JW, Benson CT, Janssens W, Bos J, Stahl E, Brady JT, Wändel-Liminga U, Corriol-Rohou S, Forster R, Hartmann A, Pertel PE, Robertson SM, Silva-Lima B, Malik RE, Chibout SD. Shared Learnings on the New EMA First-in-Human and Early Clinical Trial Guideline: Proceedings From a DIAlogue Session at DIA Europe 2018. Ther Innov Regul Sci 2019. [DOI: 10.1177/2168479019843514] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Affiliation(s)
- Jan Willem van der Laan
- Section on Pharmacology, Toxicology and Kinetics, Medicines Evaluation Board, Utrecht, the Netherlands
| | - Charles T. Benson
- Clinical Pharmacology—San Diego, Eli Lilly and Company, Indianapolis, IN
| | - Walter Janssens
- Federal Agency For Medicines and Health Products, Brussels, Belgium
| | - Jeroen Bos
- Regulatory Affairs, Novartis Pharma, Basel, Switzerland
| | - Elke Stahl
- Clinical Trial Unit, Federal Institute for Drugs and Medical Devices, BfArM, Bonn, Germany
| | - Joseph T. Brady
- Drug Safety Research and Development, Pfizer, INC, Cambridge, MA
| | | | | | | | | | | | | | - Beatriz Silva-Lima
- Department of Pharmacology, Universidade de Lisboa, Lisboa, Portugal
- NDA Advisory Board, UK
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Wager TT, Kormos BL, Brady JT, Will Y, Aleo MD, Stedman DB, Kuhn M, Chandrasekaran RY. Improving the Odds of Success in Drug Discovery: Choosing the Best Compounds for in Vivo Toxicology Studies. J Med Chem 2013; 56:9771-9. [DOI: 10.1021/jm401485p] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Affiliation(s)
- Travis T. Wager
- Pfizer Worldwide Research and Development, 700 Main Street, Cambridge, Massachusetts 02139, United States
| | - Bethany L. Kormos
- Pfizer Worldwide Research and Development, 700 Main Street, Cambridge, Massachusetts 02139, United States
| | - Joseph T. Brady
- Pfizer Worldwide Research and Development, Eastern Point Road, Groton, Connecticut 06340, United States
| | - Yvonne Will
- Pfizer Worldwide Research and Development, Eastern Point Road, Groton, Connecticut 06340, United States
| | - Michael D. Aleo
- Pfizer Worldwide Research and Development, Eastern Point Road, Groton, Connecticut 06340, United States
| | - Donald B. Stedman
- Pfizer Worldwide Research and Development, Eastern Point Road, Groton, Connecticut 06340, United States
| | - Max Kuhn
- Pfizer Worldwide Research and Development, Eastern Point Road, Groton, Connecticut 06340, United States
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Criswell KA, Cook JC, Wojcinski Z, Pegg D, Herman J, Wesche D, Giddings J, Brady JT, Anderson T. Mode of action associated with development of hemangiosarcoma in mice given pregabalin and assessment of human relevance. Toxicol Sci 2012; 128:57-71. [PMID: 22539620 DOI: 10.1093/toxsci/kfs149] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Pregabalin increased the incidence of hemangiosarcomas in carcinogenicity studies of 2-year mice but was not tumorigenic in rats. Serum bicarbonate increased within 24 h of pregabalin administration in mice and rats. Rats compensated appropriately, but mice developed metabolic alkalosis and increased blood pH. Local tissue hypoxia and increased endothelial cell proliferation were also confirmed in mice alone. The combination of hypoxia and sustained increases in endothelial cell proliferation, angiogenic growth factors, dysregulated erythropoiesis, and macrophage activation is proposed as the key event in the mode of action (MOA) for hemangiosarcoma formation. Hemangiosarcomas occur spontaneously in untreated control mice but occur only rarely in humans. The International Programme on Chemical Safety and International Life Sciences Institute developed a Human Relevance Framework (HRF) analysis whereby presence or absence of key events can be used to assess human relevance. The HRF combines the MOA with an assessment of biologic plausibility in humans to assess human relevance. This manuscript compares the proposed MOA with Hill criteria, a component of the HRF, for strength, consistency, specificity, temporality, and dose response, with an assessment of key biomarkers in humans, species differences in response to disease conditions, and spontaneous incidence of hemangiosarcoma to evaluate human relevance. Lack of key biomarker events in the MOA in rats, monkeys, and humans supports a species-specific process and demonstrates that the tumor findings in mice are not relevant to humans at the clinical dose of pregabalin. Based on this collective dataset, clinical use of pregabalin would not pose an increased risk for hemangiosarcoma to humans.
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Affiliation(s)
- Kay A Criswell
- Pfizer Worldwide Research & Development, Drug Safety Research & Development, Groton, Connecticut 06340, USA.
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Rothenberg SJ, Barnett JF, Dearlove GE, Parker RM, Ball DJ, Brady JT, Yeh HC, Greenspan BJ. Characterization of a microprocessor-controlled tubular multiple metered dose inhaler aerosol generator for inhalation exposures of pharmaceuticals. J Aerosol Med 2001; 13:157-67. [PMID: 11066019 DOI: 10.1089/jam.2000.13.157] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
A microprocessor-controlled tubular multiple metered dose inhaler (MDI) aerosol generator was constructed for the delivery of pharmaceutical aerosols to inhalation chambers. The MDIs were mounted in four cassettes containing one to four MDIs on a stepped end plate. The MDIs in each cassette were pneumatically activated at intervals that were controlled by the microprocessor. The cassettes permitted easy replacement of each set of MDIs with a fresh set of MDIs whenever necessary. Aerosol concentration was controlled by varying the number of active MDIs in each cassette and the frequency of activations per minute of each row. Aerosol from the MDIs flowed along the long axis of the tube, which provided a path length sufficient to diminish impaction losses. Using a light-scattering device to monitor the aerosol concentration, the pulsatile output from the MDIs in the cassettes was demonstrated to be adequately damped out provided that the dilution/mixing/aging chamber exceeded 3 ft in length. The tube diameter selected was the minimum compatible with mounting the required number of MDIs so that the linear velocity of the aerosol was adequate to efficiently transport the aerosol out of the dilution chamber. Aerosol concentration and particle size data were recorded for a nose-only rodent exposure chamber. Reproducible aerosol concentrations ranging from 0.03 to 0.6 mg/L were generated. Particle sizes ranged from 2- to 3-microm mass median aerodynamic diameter. Thus, the aerosol generated was within the size range suitable for inhalation exposures.
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Affiliation(s)
- S J Rothenberg
- Primedica Argus Research Laboratories, Horsham, Pennsylvania 19044, USA.
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Abstract
OBJECTIVE To determine whether QT interval is prolonged or sudden death is caused by ventricular fibrillation resulting from torsades de pointes and to identify hemodynamic effects of ontazolast. ANIMALS 28 Beagles. PROCEDURE Physiologic variables were measured for 2 hours in conscious dogs given ontazolast (0, 1, or 3 mg/kg of body weight, IV) and for 1 hour in anesthetized dogs given cumulative doses of ontazolast (0, 1, 3, 6, or 8 mg/kg, IV). RESULTS Ontazolast prolonged QT interval and QT interval corrected for heart rate (QTc) at doses of 6 mg/kg in anesthetized dogs. At 8 mg/kg, both variables remained prolonged but tended to decrease. In conscious dogs, ontazolast increased QT interval and QTc 15 minutes after administration, but both variables returned to reference ranges by 60 minutes. In conscious dogs, ontazolast increased maximum rate of increase of left ventricular pressure and maximal velocity of fiber shortening, indicators of inotropy, and increased tau, indicating a decreased rate of relaxation. One conscious dog receiving 3 mg/kg developed nonfatal torsades de pointes, but another conscious dog developed ventricular fibrillation. Two anesthetized dogs receiving 6 mg/kg developed early afterdepolarizations, and all dogs developed secondary components in theirT waves. CONCLUSION AND CLINICAL RELEVANCE Ontazolast possesses potent class-III antiarrhythmic properties and induces prolongation of QTc in a dose-dependent fashion. Because there was a clear dose-dependent prolongation of QT interval in all instances, ontazolast may serve as a positive-control compound for studying other compounds that are believed to prolong the QT interval.
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Affiliation(s)
- R L Hamlin
- Department of Veterinary Biosciences, College of Veterinary Medicine, The Ohio State University, Columbus 43210-1092, USA
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Brady JT, Birge RB, Khairallah EA, Cohen SD. Post-treatment protection with piperonyl butoxide against acetaminophen hepatotoxicity is associated with changes in selective but not total covalent binding. Adv Exp Med Biol 1991; 283:689-92. [PMID: 2069040 DOI: 10.1007/978-1-4684-5877-0_88] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Affiliation(s)
- J T Brady
- Toxicology Program: Department of Pharmacology, University of Connecticut, Storrs 06269
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Beierschmitt WP, Brady JT, Bartolone JB, Wyand DS, Khairallah EA, Cohen SD. Selective protein arylation and the age dependency of acetaminophen hepatotoxicity in mice. Toxicol Appl Pharmacol 1989; 98:517-29. [PMID: 2718178 DOI: 10.1016/0041-008x(89)90180-4] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Male CD-1 mice 1, 1.5, 2, and 3 months old were given 600 mg of acetaminophen (APAP)/kg, po, and liver damage was assessed 12 hr later. The most severe hepatotoxicity was in 3-month-old mice, while the other age groups exhibited little damage. The onset of susceptibility to APAP hepatotoxicity did not correlate with the level of activity of the mixed-function oxidase system as assessed in vitro, since drug metabolizing capability was similar between 2- and 3-month-old mice. Through 4 hr after administration of APAP to 2- and 3-month-old mice in vivo, glutathione (GSH) depletion and both plasma and liver APAP concentrations were similar between ages. Additionally, 24 hr after dosing, 3-month-old mice excreted marginally more APAP-glucuronide conjugate and parent compound in urine than 2-month-old animals, while both age groups excreted similar amounts of the APAP-sulfate and GSH-derived conjugates. Even though the extent of binding of radioactive APAP to macromolecules at 4 hr was similar between 2- and 3-month-old animals, the pattern of immunochemically targetted cytosolic and microsomal proteins was different. Thus, in APAP exposure the extent of binding to specific proteins rather than the overall amount of covalent binding may be the critical determinant of the hepatotoxic response. In the present study, the age-related differences in susceptibility to APAP-induced hepatotoxicity were related to the differences in selective protein arylation.
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Affiliation(s)
- W P Beierschmitt
- Section of Pharmacology and Toxicology, School of Pharmacy, University of Connecticut, Storrs 06269
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Brady JT, Montelius DA, Beierschmitt WP, Wyand DS, Khairallah EA, Cohen SD. Effect of piperonyl butoxide post-treatment on acetaminophen hepatotoxicity. Biochem Pharmacol 1988; 37:2097-9. [PMID: 3377813 DOI: 10.1016/0006-2952(88)90562-x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Affiliation(s)
- J T Brady
- Department of Pharmacology and Toxicology, University of Connecticut, Storrs 06268
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Abstract
A sensitive and specific method is presented for the quantification of disopyramide, a new antiarrhythmic agent, in blood plasma or serum. Aminopentamide, a chemically similar compound, is added to the biological fluid, and the two compounds are extracted with chloroform. The concentrated extract is treated with trifluoroacetic anhydride, resulting in the dehydration of the primary amide group of the drug and internal standard to the corresponding nitriles. The dehydrated derivatives are gas chromatographed and detected using a nitrogen-phosphorus detector. The method is applicable to the determination of the drug in plasma in the 1-10 microgram/mL concentration range.
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Peck CC, Odom DG, Friedman HI, Albro PW, Hass JR, Brady JT, Jess DA. Di-2-ethylhexyl phthalate (DEHP) and mono-2-ethylhexyl phthalate (MEHP) accumulation in whole blood and red cell concentrates. Transfusion 1979; 19:137-46. [PMID: 432924 DOI: 10.1046/j.1537-2995.1979.19279160282.x] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Plasma DEHP concentrations were measured weekly in whole blood and red cell concentrates (RCC) during 21 days of storage in standard CPD within PL-130 blood bags. In addition, DEHP and MEHP accumulation patterns were investigated in blood stored for 42 days in modified CPD with adenine within PL-146 and BB-69 storage containers. Total per-unit plasma DEHP of RCC units was 49 to 71 per cent of the total in plasma of whole blood units (PL-130). From 28 to 42 days, mean DEHP levels were 12 to 19 per cent higher in whole blood stored in PL-146 than in BB-69. Although MEHP was not found in any blood bag plastic, MEHP accumulated in plasma during whole blood storage. MEHP concentrations were 2.8 to 3.8 times higher in plasma stored in BB-69 than in PL-146. It is postulated that MEHP arises from hydrolysis of DEHP by plasma lipase, even in frozen plasma sample, and that the rate of this reaction is influenced by blood bag plastic surface characteristics.
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Abstract
A reaction which oligomerizes nucleotides under possible prebiotic conditions has been characterized. Nucleoside monophosphate in the presence of cyanamide at acid pH condenses to form dithymideine pyrophosphate and phosphodiester bonded compounds. Imidazole compounds and activated precursors such as nucleoside triphosphate are not necessary for this ologomerization reaction which produces primarily cyclic ologonucleotides.
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Brady JT, Zagorski JA. Collaborative Study of Enzymatic Glucose Determination in Corn Starch Hydrolysates. J AOAC Int 1969. [DOI: 10.1093/jaoac/52.3.556] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Abstract
Glucose in starch hydrolysates was determined by catalytic oxidation of glucose with glucose oxidase to form hydrogen peroxide which, in the presence of peroxidase and a chromogen, yields a colored product. This product, when acidified, is very stable and the color intensity is proportional to the glucose concentration in the sample. Fermco Test S.F.G., a package containing all the ingredients necessary for the reaction, was used. Eleven collaborators who analyzed five different sirup samples found the method to be adequate for determining glucose. Results compared well with those by paper and gas chromatography. The method is recommended for adoption as official first action.
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Affiliation(s)
- J T Brady
- Union Division, Miles Laboratories, Inc., 900 19th St., Granite City, Ill. 62040
| | - J A Zagorski
- Union Division, Miles Laboratories, Inc., 900 19th St., Granite City, Ill. 62040
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Walwick ER, Brady JT, Kay RE. Evaluation of T3 coliphage injuries and efficacy of selected materials in preventing them. Appl Microbiol 1967; 15:885-92. [PMID: 4860532 PMCID: PMC547088 DOI: 10.1128/am.15.4.885-892.1967] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
A procedure was developed to analyze the inactivation of coliphage T3 during freeze-drying and subsequent rehydration. The amount of gross disruption of the phage as compared with the amount of phage remaining intact was evaluated by cesium chloride density gradient centrifugation. The amount of phage material able to adsorb to host cells and the residual infectivity after the drying were also evaluated. These analyses made it possible to determine the amount of phage material (i) degraded to protein and nucleic acid, (ii) intact or largely intact, (iii) capable of adsorption on host cells, and (iv) infective. The capacities of casein hydrolysate, ascorbic acid, thiourea, bovine albumin, polyethyleneglycol, raffinose, inositol, and lipoproteins to protect T3 bacteriophage from the stress of freeze-drying were investigated.
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