Discovery of (4-Pyrazolyl)-2-aminopyrimidines as Potent and Selective Inhibitors of Cyclin-Dependent Kinase 2.

CDK2 is a critical regulator of the cell cycle. For a variety of human cancers, the dysregulation of CDK2/cyclin E1 can lead to tumor growth and proliferation. Historically, early efforts to develop CDK2 inhibitors with clinical applications proved unsuccessful due to challenges in achieving selectivity over off-target CDK isoforms with associated toxicity. In this report, we describe the discovery of (4-pyrazolyl)-2-aminopyrimidines as a potent class of CDK2 inhibitors that display selectivity over CDKs 1, 4, 6, 7, and 9. SAR studies led to the identification of compound 17, a kinase selective and highly potent CDK2 inhibitor (IC50 = 0.29 nM). The evaluation of 17 in CCNE1-amplified mouse models shows the pharmacodynamic inhibition of CDK2, measured by reduced Rb phosphorylation, and antitumor activity.

Discovery of 1'-(1-phenylcyclopropane-carbonyl)-3H-spiro[isobenzofuran-1,3'-pyrrolidin]-3-one as a novel steroid mimetic scaffold for the potent and tissue-specific inhibition of 11ß-HSD1 using a scaffold-hopping approach.

11ß-hydroxysteroid dehydrogenase 1 (11ß-HSD1) has been identified as the primary enzyme responsible for the activation of hepatic cortisone to cortisol in specific peripheral tissues resulting in the concomitant antagonism of insulin action within these tissues. Dysregulation of 11ß-HSD1, particularly in adipose tissues, has been associated with metabolic syndrome and type 2 diabetes mellitus. Therefore, inhibition of 11ß-HSD1 with a small nonsteroidal molecule is therapeutically desirable. Implementation of a scaffold-hopping approach revealed a three-point pharmacophore for 11ß-HSD1 that was utilized to design a steroid mimetic scaffold. Reiterative optimization provided valuable insight into the bioactive conformation of our novel scaffold and led to the discovery of INCB13739. Clinical evaluation of INCB13739 confirmed for the first time that tissue-specific inhibition of 11ß-HSD1 in patients with type 2 diabetes mellitus was efficacious in controlling glucose levels and reducing cardiovascular risk factors.

Discovery of Pemigatinib: A Potent and Selective Fibroblast Growth Factor Receptor (FGFR) Inhibitor.

Aberrant activation of FGFR has been linked to the pathogenesis of many tumor types. Selective inhibition of FGFR has emerged as a promising approach for cancer treatment. Herein, we describe the discovery of compound 38 (INCB054828, pemigatinib), a highly potent and selective inhibitor of FGFR1, FGFR2, and FGFR3 with excellent physiochemical properties and pharmacokinetic profiles. Pemigatinib has received accelerated approval from the U.S. Food and Drug Administration for the treatment of adults with previously treated, unresectable locally advanced or metastatic cholangiocarcinoma with a FGFR2 fusion or other rearrangement. Additional clinical trials are ongoing to evaluate pemigatinib in patients with FGFR alterations.

MicroRNA-379 inhibits metastasis and epithelial-mesenchymal transition via targeting FAK/AKT signaling in gastric cancer.

Accumulating evidence demonstrates that aberrant miRNAs contribute to gastric cancer (GC) development and progression. However, the roles of various miRNAs in GC remain to be determined. In the present study, we confirmed that a reduced miR-379 expression was present in GC tissues and cell lines. Our clinical analysis revealed that the downregulated miR-379 expression was significantly correlated with poor prognostic features including lymph node metastasis and advanced TNM stage. Moreover, we confirmed that miR-379 was a novel independent prognostic marker for predicting 5-year survival of GC patients. The ectopic overexpression of miR-379 inhibited cell migration, invasion and EMT progress, while downregulated miR-379 reversed the effect. In addition, miR-379 regulated the focal adhesion kinase (FAK) by directly binding to its 3'-UTR, resulting in suppression of AKT signaling. In clinical samples of GC, miR-379 inversely correlated with FAK, which was upregulated in GC. Alteration of FAK expression or activating AKT signaling at least partially abolished the migration, invasion and EMT progress effects of miR-379 on GC cells. In conclusion, our results indicated that miR-379 functioned as a tumor suppressor gene in regulating the EMT and metastasis of GC via targeting FAK/AKT signaling, and may represent a novel potential therapeutic target and prognostic marker for GC.

A novel kinase inhibitor, INCB28060, blocks c-MET-dependent signaling, neoplastic activities, and cross-talk with EGFR and HER-3.

PURPOSE: The c-MET receptor tyrosine kinase plays important roles in the formation, progression, and dissemination of human cancer and presents an attractive therapeutic target. This study describes the preclinical characterization of INCB28060, a novel inhibitor of c-MET kinase. EXPERIMENTAL DESIGN: Studies were conducted using a series of in vitro and in vivo biochemical and biological experiments. RESULTS: INCB28060 exhibits picomolar enzymatic potency and is highly specific for c-MET with more than 10,000-fold selectivity over a large panel of human kinases. This inhibitor potently blocks c-MET phosphorylation and activation of its key downstream effectors in c-MET-dependent tumor cell lines. As a result, INCB28060 potently inhibits c-MET-dependent tumor cell proliferation and migration and effectively induces apoptosis in vitro. Oral dosing of INCB28060 results in time- and dose-dependent inhibition of c-MET phosphorylation and tumor growth in c-MET-driven mouse tumor models, and the inhibitor is well tolerated at doses that achieve complete tumor inhibition. In a further exploration of potential interactions between c-MET and other signaling pathways, we found that activated c-MET positively regulates the activity of epidermal growth factor receptors (EGFR) and HER-3, as well as expression of their ligands. These effects are reversed with INCB28060 treatment. Finally, we confirmed that circulating hepatocyte growth factor levels are significantly elevated in patients with various cancers. CONCLUSIONS: Activated c-MET has pleiotropic effects on multiple cancer-promoting signaling pathways and may play a critical role in driving tumor cell growth and survival. INCB28060 is a potent and selective c-MET kinase inhibitor that may have therapeutic potential in cancer treatment.

Compelling P1 substituent affect on metalloprotease binding profile enables the design of a novel cyclohexyl core scaffold with excellent MMP selectivity and HER-2 sheddase inhibition.

A serendipitous discovery that the metalloprotease binding profile of a novel class of 2-carboxamide-3-hydroxamic acid piperidines could be significantly attenuated by the modification of the unexplored P1 substituent enabled the design and synthesis of a novel 2-carboxamide-1-hydroxamic acid cyclohexyl scaffold core that exhibited excellent HER-2 potency and unprecedented MMP-selectivity that we believe would not have been possible via conventional P1' perturbations.

Design and identification of selective HER-2 sheddase inhibitors via P1' manipulation and unconventional P2' perturbations to induce a molecular metamorphosis.

In an effort to obtain a MMP selective and potent inhibitor of HER-2 sheddase (ADAM-10), the P1' group of a novel class of (6S,7S)-7-[(hydroxyamino)carbonyl]-6-carboxamide-5-azaspiro[2.5]octane-5-carboxylates was attenuated and the structure-activity relationships (SAR) will be discussed. In addition, it was discovered that unconventional perturbation of the P2' moiety could confer MMP selectivity, which was hypothesized to be a manifestation of the P2' group effecting global conformational changes.

Discovery of a potent, selective, and orally active human epidermal growth factor receptor-2 sheddase inhibitor for the treatment of cancer.

The design, synthesis, evaluation, and identification of a novel class of (6S,7S)-N-hydroxy-6-carboxamide-5-azaspiro[2.5]octane-7-carboxamides as the first potent and selective inhibitors of human epidermal growth factor receptor-2 (HER-2) sheddase is described. Several compounds were identified that possess excellent pharmacodynamic and pharmacokinetic properties and were shown to decrease tumor size, cleaved HER-2 extracellular domain plasma levels, and potentiate the effects of the humanized anti-HER-2 monoclonal antibody (trastuzumab) in vivo in a HER-2 overexpressing cancer murine xenograft model.

Identification of ADAM10 as a major source of HER2 ectodomain sheddase activity in HER2 overexpressing breast cancer cells.

Overexpression and activating mutations of ErbB family members have been implicated in the development and progression of a variety of tumor types. Cleavage of the HER2 receptor by an as yet unidentified ectodomain sheddase has been shown to liberate the HER2 extracellular domain (ECD) leaving a fragment with constitutive kinase activity that can provide ligand-independent growth and survival signals to the cell. This process is clinically relevant since HER2 ECD serum levels in metastatic breast cancer patients are associated with a poorer prognosis. Thus, inhibition of the HER2 sheddase may provide a novel therapeutic approach for breast cancer. We describe the use of transcriptional profiling, pharmacological and in vitro approaches to identify the major source of HER2 sheddase activity. Real-time PCR was used to identify those ADAM family members which were expressed in HER2 shedding cell lines. siRNAs that selectively inhibited ADAM10 expression reduced HER2 shedding. In addition, we profiled over 1000 small molecules for in vitro inhibition of a panel of ADAM and MMP proteins; a positive correlation was observed only between ADAM10 inhibition and reduction of HER2 ECD shedding in a cell based assay. Finally, in vitro studies demonstrate that in combination with low doses of Herceptin, selective ADAM10 inhibitors decrease proliferation in HER2 overexpressing cell lines while inhibitors, that do not inhibit ADAM10, have no impact. These results are consistent with ADAM10 being a major determinant of HER2 shedding, the inhibition of which, may provide a novel therapeutic approach for treating a variety of cancers with active HER2 signaling.

Both 5-arylidene-2-thioxodihydropyrimidine-4,6(1H,5H)-diones and 3-thioxo-2,3-dihydro-1H-imidazo[1,5-a]indol-1-ones are light-dependent tumor necrosis factor-alpha antagonists.

Based on the realization that N-alkyl 5-arylidene-2-thioxo-1,3-thiazolidin-4-ones are tumor necrosis factor-alpha antagonists, we discovered two additional classes of antagonists: 3-thioxo-2,3-dihydro-1H-imidazo[1,5-a]indol-1-ones (via rational design) and 5-arylidene-2-thioxodihydropyrimidine-4,6(1H,5H)-diones (via computer-guided screening). Chemical modification of the lead structures showed that the structure-activity relationship profiles for both of these series were dependent on the electronic properties of the molecules. Subsequent studies showed that they were light-dependent inhibitors.