title: Preclinical pharmacology, antitumor activity, and development of pharmacodynamic markers for the novel, potent AKT inhibitor CCT128930.
abstract: AKT is frequently deregulated in cancer, making it an attractive anticancer drug target. CCT128930 is a novel ATP-competitive AKT inhibitor discovered using fragment- and structure-based approaches. It is a potent, advanced lead pyrrolopyrimidine compound exhibiting selectivity for AKT over PKA, achieved by targeting a single amino acid difference. CCT128930 exhibited marked antiproliferative activity and inhibited the phosphorylation of a range of AKT substrates in multiple tumor cell lines in vitro, consistent with AKT inhibition. CCT128930 caused a G(1) arrest in PTEN-null U87MG human glioblastoma cells, consistent with AKT pathway blockade. Pharmacokinetic studies established that potentially active concentrations of CCT128930 could be achieved in human tumor xenografts. Furthermore, CCT128930 also blocked the phosphorylation of several downstream AKT biomarkers in U87MG tumor xenografts, indicating AKT inhibition in vivo. Antitumor activity was observed with CCT128930 in U87MG and HER2-positive, PIK3CA-mutant BT474 human breast cancer xenografts, consistent with its pharmacokinetic and pharmacodynamic properties. A quantitative immunofluorescence assay to measure the phosphorylation and total protein expression of the AKT substrate PRAS40 in hair follicles is presented. Significant decreases in pThr246 PRAS40 occurred in CCT128930-treated mouse whisker follicles in vivo and human hair follicles treated ex vivo, with minimal changes in total PRAS40. In conclusion, CCT128930 is a novel, selective, and potent AKT inhibitor that blocks AKT activity in vitro and in vivo and induces marked antitumor responses. We have also developed a novel biomarker assay for the inhibition of AKT in human hair follicles, which is currently being used in clinical trials.
authors.affiliation: Cancer Research UK Cancer Therapeutics Unit, The Institute of Cancer Research, 15 Cotswold Road, Sutton, Surrey SM2 5NG, United Kingdom.
authors.forename: Timothy A
authors.initials: TA
authors.lastname: Yap
authors.forename: Mike I
authors.initials: MI
authors.lastname: Walton
authors.forename: Lisa-Jane K
authors.initials: LJ
authors.lastname: Hunter
authors.forename: Melanie
authors.initials: M
authors.lastname: Valenti
authors.forename: Alexis
authors.initials: A
authors.lastname: de Haven Brandon
authors.forename: Paul D
authors.initials: PD
authors.lastname: Eve
authors.forename: Ruth
authors.initials: R
authors.lastname: Ruddle
authors.forename: Simon P
authors.initials: SP
authors.lastname: Heaton
authors.forename: Alan
authors.initials: A
authors.lastname: Henley
authors.forename: Lisa
authors.initials: L
authors.lastname: Pickard
authors.forename: Gowri
authors.initials: G
authors.lastname: Vijayaraghavan
authors.forename: John J
authors.initials: JJ
authors.lastname: Caldwell
authors.forename: Neil T
authors.initials: NT
authors.lastname: Thompson
authors.forename: Wynne
authors.initials: W
authors.lastname: Aherne
authors.forename: Florence I
authors.initials: FI
authors.lastname: Raynaud
authors.forename: Suzanne A
authors.initials: SA
authors.lastname: Eccles
authors.forename: Paul
authors.initials: P
authors.lastname: Workman
authors.forename: Ian
authors.initials: I
authors.lastname: Collins
authors.forename: Michelle D
authors.initials: MD
authors.lastname: Garrett
mesh_terms: D048868:Adaptor Proteins, Signal Transducing / Q000378:metabolism; D000818:Animals; D000970:Antineoplastic Agents / Q000493:pharmacokinetics / Q000494:pharmacology; D054316:Biomarkers, Pharmacological / Q000032:analysis*; D002453:Cell Cycle / Q000187:drug effects; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects; D005260:Female; D015972:Gene Expression Regulation, Neoplastic / Q000187:drug effects; D045325:HCT116 Cells; D018859:Hair Follicle / Q000378:metabolism; D006801:Humans; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D008819:Mice, Nude; D009369:Neoplasms / Q000201:enzymology; D047428:Protein Kinase Inhibitors / Q000737:chemistry / Q000493:pharmacokinetics* / Q000494:pharmacology*; D051057:Proto-Oncogene Proteins c-akt / Q000037:antagonists & inhibitors*; D011743:Pyrimidines / Q000737:chemistry / Q000493:pharmacokinetics* / Q000494:pharmacology*; D011758:Pyrroles / Q000737:chemistry / Q000493:pharmacokinetics* / Q000494:pharmacology*; D023041:Xenograft Model Antitumor Assays
chemical_list: C561680:4-(4-chlorobenzyl)-1-(7H-pyrrolo(2,3-d)pyrimidin-4-yl)piperidin-4-amine; C484523:AKT1S1 protein, human; D048868:Adaptor Proteins, Signal Transducing; D000970:Antineoplastic Agents; D054316:Biomarkers, Pharmacological; D047428:Protein Kinase Inhibitors; D011743:Pyrimidines; D011758:Pyrroles; D051057:Proto-Oncogene Proteins c-akt