title: Inhibition mechanism exploration of investigational drug TAK-441 as inhibitor against Vismodegib-resistant Smoothened mutant.
abstract: Hedgehog signaling is a driving force in medulloblastoma and basal cell carcinoma (BCC), making it an attractive therapeutic target. Vismodegib recently received FDA approval for the treatment of inoperable BCC, but a drug-resistant Smoothened (Smo) mutant (D473H) was identified in a clinical study. TAK-441 is a pyrrolo[3,2-c]pyridine-4-one derivative that potently inhibits Hh signal transduction and is currently under investigation in clinical trials. We demonstrated that TAK-441 inhibits reporter activity in D473H-transfected cells with an IC50 of 79nM, while Vismodegib showed an IC50=7100nM. In order to investigate the mode of inhibition, we evaluated the Smo inhibitors with three different binding assays, such as [(3)H]-TAK-441 membrane binding assay, affinity selection-MS detection assay, and bodipy-cylopamine whole cell assay. In three different assays, Vismodegib and cyclopamine showed lower affinity for the D473H mutant in comparison with wild-type Smo. On the other hand, TAK-441 showed almost equal binding affinity for the D473H mutant compared with wild-type Smo in the binding assays, although TAK-441 binds to the same binding site as two other well-known inhibitors. These in vitro findings suggest that TAK-441 has the potential for clinical use in cancers that are dependent on Hedgehog signaling, including wild-type tumors and Vismodegib-resistant D473H mutants.
authors.affiliation: Pharmaceutical Research Division, Takeda Pharmaceutical Company Limited, 26-1, Muraoka-Higashi 2-Chome, Fujisawa, Kanagawa 251-8555, Japan. Electronic address: tsuyoshi.ishii@takeda.com.
authors.forename: Tsuyoshi
authors.initials: T
authors.lastname: Ishii
authors.affiliation: Pharmaceutical Research Division, Takeda Pharmaceutical Company Limited, 26-1, Muraoka-Higashi 2-Chome, Fujisawa, Kanagawa 251-8555, Japan.
authors.forename: Yuji
authors.initials: Y
authors.lastname: Shimizu
authors.affiliation: Pharmaceutical Research Division, Takeda Pharmaceutical Company Limited, 26-1, Muraoka-Higashi 2-Chome, Fujisawa, Kanagawa 251-8555, Japan.
authors.forename: Kosuke
authors.initials: K
authors.lastname: Nakashima
authors.affiliation: Pharmaceutical Research Division, Takeda Pharmaceutical Company Limited, 26-1, Muraoka-Higashi 2-Chome, Fujisawa, Kanagawa 251-8555, Japan.
authors.forename: Shigeru
authors.initials: S
authors.lastname: Kondo
authors.affiliation: Pharmaceutical Research Division, Takeda Pharmaceutical Company Limited, 26-1, Muraoka-Higashi 2-Chome, Fujisawa, Kanagawa 251-8555, Japan.
authors.forename: Kazumasa
authors.initials: K
authors.lastname: Ogawa
authors.affiliation: Pharmaceutical Research Division, Takeda Pharmaceutical Company Limited, 26-1, Muraoka-Higashi 2-Chome, Fujisawa, Kanagawa 251-8555, Japan.
authors.forename: Satoshi
authors.initials: S
authors.lastname: Sasaki
authors.affiliation: Pharmaceutical Research Division, Takeda Pharmaceutical Company Limited, 26-1, Muraoka-Higashi 2-Chome, Fujisawa, Kanagawa 251-8555, Japan.
authors.forename: Hideki
authors.initials: H
authors.lastname: Matsui
mesh_terms: D000813:Anilides / Q000494:pharmacology; D000818:Animals; D000970:Antineoplastic Agents / Q000494:pharmacology*; D019008:Drug Resistance, Neoplasm; D015507:Drugs, Investigational / Q000494:pharmacology*; D057809:HEK293 Cells; D053823:Hedgehog Proteins / Q000037:antagonists & inhibitors*; D006801:Humans; D051379:Mice; D009154:Mutation; D041681:NIH 3T3 Cells; D011725:Pyridines / Q000494:pharmacology*; D011758:Pyrroles / Q000494:pharmacology*; D043562:Receptors, G-Protein-Coupled / Q000037:antagonists & inhibitors* / Q000235:genetics / Q000378:metabolism; D000072086:Smoothened Receptor
chemical_list: D000813:Anilides; D000970:Antineoplastic Agents; D015507:Drugs, Investigational; D053823:Hedgehog Proteins; C538724:HhAntag691; D011725:Pyridines; D011758:Pyrroles; D043562:Receptors, G-Protein-Coupled; C491023:SMO protein, human; D000072086:Smoothened Receptor; C577980:TAK-441
keywords: D473H; GDC-0449; Hedgehog; Smo; TAK-441; Vismodegib