PDF file - 553K, Supplementary Figure 1. Phosphorylation of AKT substrates remains suppressed, despite pSer473 AKT induction. Supplementary Figure 2. The pharmacokinetic-pharmacodynamic profile and antitumor activity of AT13148 in PTEN-deficient PC3 human prostate cancer xenografts. Supplementary Figure 3. Pharmacodynamic biomarker study of AT13148(40mg/kg) in MES-SA human tumor xenografts. Supplementary Figure 4. The antitumour activity of AT13148 in mutant KRAS A549 human lung cancer xenografts. Supplementary Figure 5. Mouse body weight data for the MES-SA (Figure 4B) and BT474 (Figure 4C) efficacy studies. Supplementary Figure 6. The effect of AT13148 versus CCT128930 on apoptosis and cell cycle distribution in U87MG human glioblastoma cells. Supplementary Figure 7. Differential effects of 24h treatment of 10M each of the AGC kinase inhibitor AT13148 and the selective AKT inhibitor CCT128930 on cell cycle effects in PTEN-deficient U87MG human glioblastoma cells. Supplementary Table 1. Summary of the inhibitory activity of 10��M AT13148 against in vitro. Supplementary Table 2. Summary of the inhibitory activity of AT13148 against a panel of protein kinases Supplementary Table 3. Summary of the in vitro cytotoxicity of AT13148 against a panel of human tumor cell lines harboring different defects in the PI3K-AKT signaling pathway. Supplementary Table 4. Summary of the pharmacokinetics of AT13148 in mouse plasma and tissues following iv or oral administration
ARTICLE ABSTRACT
Purpose: Deregulated phosphatidylinositol 3-kinase pathway signaling through AGC kinases including AKT, p70S6 kinase, PKA, SGK and Rho kinase is a key driver of multiple cancers. The simultaneous inhibition of multiple AGC kinases may increase antitumor activity and minimize clinical resistance compared with a single pathway component.Experimental Design: We investigated the detailed pharmacology and antitumor activity of the novel clinical drug candidate AT13148, an oral ATP-competitive multi-AGC kinase inhibitor. Gene expression microarray studies were undertaken to characterize the molecular mechanisms of action of AT13148.Results: AT13148 caused substantial blockade of AKT, p70S6K, PKA, ROCK, and SGK substrate phosphorylation and induced apoptosis in a concentration and time-dependent manner in cancer cells with clinically relevant genetic defects in vitro and in vivo. Antitumor efficacy in HER2-positive, PIK3CA-mutant BT474 breast, PTEN-deficient PC3 human prostate cancer, and PTEN-deficient MES-SA uterine tumor xenografts was shown. We show for the first time that induction of AKT phosphorylation at serine 473 by AT13148, as reported for other ATP-competitive inhibitors of AKT, is not a therapeutically relevant reactivation step. Gene expression studies showed that AT13148 has a predominant effect on apoptosis genes, whereas the selective AKT inhibitor CCT128930 modulates cell-cycle genes. Induction of upstream regulators including IRS2 and PIK3IP1 as a result of compensatory feedback loops was observed.Conclusions: The clinical candidate AT13148 is a novel oral multi-AGC kinase inhibitor with potent pharmacodynamic and antitumor activity, which shows a distinct mechanism of action from other AKT inhibitors. AT13148 will now be assessed in a first-in-human phase I trial. Clin Cancer Res; 18(14); 3912–23. ©2012 AACR.
