title: Pharmacokinetic and pharmacodynamic modeling of hedgehog inhibitor TAK-441 for the inhibition of Gli1 messenger RNA expression and antitumor efficacy in xenografted tumor model mice.
abstract: 6-Ethyl-N-[1-(hydroxyacetyl)piperidin-4-yl]-1-methyl-4-oxo-5-(2-oxo-2-phenylethyl)-3-(2,2,2-trifluoroethoxy)-4,5-dihydro-1H-pyrrolo[3,2-c]pyridine-2-carboxamide (TAK-441) is a potent, selective hedgehog signaling pathway inhibitor that binds to Smo and is being developed for the treatment of cancer. The objectives of these studies were to explore the possibility of establishing of a link between the pharmacokinetics of TAK-441 and the responses of Gli1 mRNA in tumor-associated stromal or skin cells and the antitumor effect of hedgehog inhibition. To this end, we built pharmacokinetic and pharmacodynamic models that describe the relationship of the concentrations of TAK-441 plasma to the responses of Gli1 mRNA in the tumor (target) and skin (surrogate) and to tumor growth inhibition in mice bearing xenografts of human pancreatic tumors (PAN-04). The responses of Gli1 mRNA and tumor growth were described by an indirect response model and an exponential tumor growth model, respectively. The IC50 values for Gli1 mRNA inhibition in the tumor and skin by TAK-441 were estimated to be 0.0457 and 0.113 μg/ml, respectively. The IC90 value for tumor growth inhibition was estimated to be 0.68 μg/ml. These results suggest that a >83% inhibition of Gli1 mRNA expression in the skin or a >94% inhibition of Gli1 mRNA expression in the tumor would be required to sufficiently inhibit (>90%) hedgehog-related tumor growth in the xenografted model mice. We conclude that Gli1 mRNA expression in the tumor and skin could be a useful biomarker for predicting the antitumor effect of hedgehog inhibitors.
authors.affiliation: Drug Metabolism and Pharmacokinetics Research Laboratories, Pharmaceutical Research Division, Takeda Pharmaceutical Company Limited, Kanagawa, Japan. akifumi.kogame@takeda.com
authors.forename: Akifumi
authors.initials: A
authors.lastname: Kogame
authors.forename: Yoshihiko
authors.initials: Y
authors.lastname: Tagawa
authors.forename: Sachio
authors.initials: S
authors.lastname: Shibata
authors.forename: Hideaki
authors.initials: H
authors.lastname: Tojo
authors.forename: Maki
authors.initials: M
authors.lastname: Miyamoto
authors.forename: Kimio
authors.initials: K
authors.lastname: Tohyama
authors.forename: Takahiro
authors.initials: T
authors.lastname: Kondo
authors.forename: Shimoga
authors.initials: S
authors.lastname: Prakash
authors.forename: Wen Chyi
authors.initials: WC
authors.lastname: Shyu
authors.forename: Satoru
authors.initials: S
authors.lastname: Asahi
mesh_terms: D000818:Animals; D000970:Antineoplastic Agents / Q000493:pharmacokinetics* / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D005260:Female; D015870:Gene Expression / Q000187:drug effects*; D053823:Hedgehog Proteins / Q000037:antagonists & inhibitors*; D006801:Humans; D051379:Mice; D008954:Models, Biological; D009369:Neoplasms / Q000378:metabolism; D015513:Oncogene Proteins / Q000235:genetics*; D011725:Pyridines / Q000493:pharmacokinetics* / Q000494:pharmacology*; D011758:Pyrroles / Q000493:pharmacokinetics* / Q000494:pharmacology*; D012333:RNA, Messenger / Q000096:biosynthesis / Q000235:genetics; D012867:Skin / Q000378:metabolism; D015534:Trans-Activators / Q000235:genetics*; D023041:Xenograft Model Antitumor Assays; D000071676:Zinc Finger Protein GLI1
chemical_list: D000970:Antineoplastic Agents; D053823:Hedgehog Proteins; D015513:Oncogene Proteins; D011725:Pyridines; D011758:Pyrroles; D012333:RNA, Messenger; C577980:TAK-441; D015534:Trans-Activators; D000071676:Zinc Finger Protein GLI1