Abstract 5777: EMD 1214063, an exquisitely selective c-Met kinase inhibitor in clinical phase 1

The role of the receptor tyrosin kinase c-Met in tumor progression, metastasis and aggressiveness has been convincingly demonstrated in preclinical and early clinical settings. Several compounds with different selectivity profiles inhibiting c-Met are currently under preclinical/clinical investigation and might emerge as valuable cancer therapeutics in the future. During an HTS run N-(3-(3,6-Dihydro-5-(3,4-dimethoxyphenyl)-2-oxo-2H-1,3,4-thiadiazin-3-ylmethyl)-phenyl)-carbaminic acid-(3-(N,N-diethylamino)-propylester) (1) was identified as an attractive lead structure with an interesting overall profile (clogD (7.4): 2.5, S (pH 7.4): >100 µg/ml, IC 50 (c-Met in vitro): 30 nM, IC 50 (c-Met cellular): 800 nM) providing a valid starting point for lead optimization. The co-crystal structure of 1 revealed the binding mode and the essential structural features. The initial HTS hit was bound in a DFG-in conformation interacting namely with the main chain nitrogen atom of methionine 1160 within the hinge region and with the main chain nitrogen of aspartic acid 1222. After subsequent optimization of potency, efficacy, PK properties and the safety profile of thiadiazinone 1, EMD1214063 was identified as candidate for further development and is currently investigated in a phase 1 clinical trial. The pyridazinone EMD1214063 inhibits enzymatic and cellular c-Met kinase activity with IC 50 values in the low nanomolar range. This compound displayed an exquisite selectivity when tested in vitro against a panel of more than 250 potential off-targets, including kinases, GPCRs, ion channels, transporters and various enzymes and demonstrated excellent anti-tumor activity in vivo in a variety of xenograft models. Depending on the particular model, complete regressions were observed with doses as low as 6 mg/kg/d administered per os. The overall profile of EMD1214063 including first time disclosure of the precise structure, synthesis, structure activity relationships, in vitro potency, selectivity profile, pharmacokinetic and in vivo data will be discussed. Note: This abstract was not presented at the AACR 101st Annual Meeting 2010 because the presenter was unable to attend. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 5777.