Fused bicyclic derivatives of 2,4-diaminopyrimidine as c-Met inhibitors.

The HGF-c-Met signaling axis is an important paracrine mediator of epithelial-mesenchymal cell interactions involving the regulation of multiple cellular activities including cell motility, mitogenesis, morphogenesis, and angiogenesis. Dysregulation of c-Met signaling (e.g., overexpression or increased activation) is associated with the development of a wide range of tumor types; thus, inhibiting the HGF-c-Met pathway is predicted to lead to anti-tumor effects in many cancers. Elaboration of a 2-arylaminopyrimidine scaffold led to a series of potent c-Met inhibitors bearing a C4-2-amino-N-methylbenzamide group. Specifically, a series of C2-benzazepinone analogs demonstrated potent inhibition of c-Met in enzymatic and cellular assays. Kinase selectivity could be tuned by varying the nature of the alkyl group on the benzazepinone nitrogen.

2,4-Diaminopyrimidine inhibitors of c-Met kinase bearing benzoxazepine anilines.

Elaboration of the SAR around a series of 2,4-diaminopyrimidines led to a number of c-Met inhibitors in which kinase selectivity was modulated by substituents appended on the C4-aminobenzamide ring and the nature of the C2-aminoaryl ring. Further lead optimization of the C2-aminoaryl group led to benzoxazepine analogs whose pharmaceutical properties were modulated by the nature of the substituent on the benzoxazepine nitrogen. Tumor stasis (with partial regressions) were observed when an orally bioavailable analog was evaluated in a GTL-16 tumor xenograft mouse model. Subsequent PK/PD studies suggested that a metabolite contributed to the overall in vivo response.

Improvement in oral bioavailability of 2,4-diaminopyrimidine c-Met inhibitors by incorporation of a 3-amidobenzazepin-2-one group.

The hepatocyte growth factor (HGF)-c-Met signaling axis is involved in the mediation of many biological activities, including angiogenesis, proliferation, cell survival, cell motility, and morphogenesis. Dysregulation of c-Met signaling (e.g., overexpression or increased activation) is associated with the proliferation and metastasis of a wide range of tumor types, including breast, liver, lung, colorectal, gastric, bladder, and prostate, among others. Inhibiting the HGF-c-Met pathway is predicted to lead to anti-tumor effects in many cancers. Elaboration of the SAR around a series of 2,4-diaminopyrimidines led to a number of c-Met inhibitors in which pharmaceutical properties were modulated by substituents appended on the C2-benzazepinone ring. In particular, certain-3-amidobenzazepin-2-one analogs had improved oral bioavailability and were evaluated in PK/PD and efficacy models. Lead compounds demonstrated tumor stasis with partial regressions when evaluated in a GTL-16 tumor xenograft mouse model.

Time-resolved fluorescence resonance energy transfer as a versatile tool in the development of homogeneous cellular kinase assays.

Homogeneous cellular assays can streamline product detection in the drug discovery process. One commercially available assay employing time-resolved fluorescence resonance energy transfer (TR-FRET) that detects phosphorylated products was used to evaluate inhibitors of the receptor tyrosine kinase AXL in a cell line expressing an AXL-green fluorescent protein fusion protein. This TR-FRET assay was modified to evaluate the phosphorylation state of the AXL family member MER in a cell line expressing MER with a V5 tag by adding a fluorescein-labeled anti-V5 antibody. This homogeneous cellular assay was further modified to evaluate the nonreceptor tyrosine kinase focal adhesion kinase (FAK) in cell lines that expressed an untagged kinase by the inclusion of a commercially available anti-FAK antibody conjugated with an acceptor dye. The methods described here can be further adapted for TR-FRET detection of other cellular kinase activities.