Discovery of AMG 925, a FLT3 and CDK4 dual kinase inhibitor with preferential affinity for the activated state of FLT3.

We describe the structural optimization of a lead compound 1 that exhibits dual inhibitory activities against FLT3 and CDK4. A series of pyrido[4',3':4,5]pyrrolo[2,3-d]pyrimidine derivatives was synthesized, and SAR analysis, using cell-based assays, led to the discovery of 28 (AMG 925), a potent and orally bioavailable dual inhibitor of CDK4 and FLT3, including many FLT3 mutants reported to date. Compound 28 inhibits the proliferation of a panel of human tumor cell lines including Colo205 (Rb(+)) and U937 (FLT3(WT)) and induced cell death in MOLM13 (FLT3(ITD)) and even in MOLM13 (FLT3(ITD, D835Y)), which exhibits resistance to a number of FLT3 inhibitors currently under clinical development. At well-tolerated doses, compound 28 leads to significant growth inhibition of MOLM13 xenografts in nude mice, and the activity correlates with inhibition of STAT5 and Rb phosphorylation.

Discovery and optimization of benzenesulfonanilide derivatives as a novel class of 11ß-HSD1 inhibitors.

A novel series of benzenesulfonanilide derivatives of 11ß-HSD1 inhibitors were identified via modification of the sulfonamide core of the arylsulfonylpiperazine lead structures. The synthesis, in vitro biological evaluation, and structure-activity relationship of these compounds are presented. Optimization of this series rapidly resulted in the discovery of compounds (S)-10 and (S)-23 (11ß-HSD1 SPA IC(50)=1.8 and 1.4 nM, respectively).

Discovery of amide replacements that improve activity and metabolic stability of a bis-amide smoothened antagonist hit.

A bis-amide antagonist of Smoothened, a seven-transmembrane receptor in the Hedgehog signaling pathway, was discovered via high throughput screening. In vitro and in vivo experiments demonstrated that the bis-amide was susceptible to N-acyl transferase mediated amide scission. Several bioisosteric replacements of the labile amide that maintained in vitro potency were identified and shown to be metabolically stable in vitro and in vivo.

Improvement of the synthesis and pharmacokinetic properties of chromenotriazolopyrimidine MDM2-p53 protein-protein inhibitors.

Human murine double minute 2 (MDM2) is a negative regulator of p53, which plays an important role in cell cycle and apoptosis. We report several optimizations to the synthesis of the chromenotriazolopyrimidine series of MDM2-p53 protein-protein interaction inhibitors. Additionally, the in vitro and in vivo stability, pharmacokinetic properties and solubility were improved through N-substitution.

Synthesis and optimization of novel 4,4-disubstituted cyclohexylbenzamide derivatives as potent 11ß-HSD1 inhibitors.

The synthesis and SAR of a series of 4,4-disubstituted cyclohexylbenzamide inhibitors of 11ß-HSD1 are described. Optimization rapidly led to potent, highly selective, and orally bioavailable inhibitors demonstrating efficacy in both rat and non-human primate ex vivo pharmacodynamic models.

A novel series of IKKß inhibitors part II: description of a potent and pharmacologically active series of analogs.

A novel series of (E)-1-((2-(1-methyl-1H-imidazol-5-yl) quinolin-4-yl) methylene) thiosemicarbazides was discovered as potent inhibitors of IKKß. In this Letter we document our efforts at further optimization of this series, culminating in 2 with submicromolar potency in a HWB assay and efficacy in a CIA mouse model.

A novel series of IKKß inhibitors part I: Initial SAR studies of a HTS hit.

A novel series of (E)-1-((2-(1-methyl-1H-imidazol-5-yl) quinolin-4-yl) methylene) thiosemicarbazides was discovered as potent inhibitors of IKKß. In this Letter we document our early efforts at optimization of the quinoline core, the imidazole and the semithiocarbazone moiety. Most potency gains came from substitution around the 6- and 7-positions of the quinoline ring. Replacement of the semithiocarbazone with a semicarbazone decreased potency but led to some measurable exposure.

The synthesis and SAR of novel diarylsulfone 11ß-HSD1 inhibitors.

In this communication, human 11ß-hydroxysteroid dehydrogenase type 1 (11ß-HSD1) inhibitory activities of a novel series of diarylsulfones are described. Optimization of this series resulted in several highly potent 11ß-HSD1 inhibitors with excellent pharmacokinetic (PK) properties. Compound (S)-25 showed excellent efficacy in a non-human primate ex vivo pharmacodynamic model.

Synthesis and optimization of arylsulfonylpiperazines as a novel class of inhibitors of 11 beta-hydroxysteroid dehydrogenase type 1 (11 beta-HSD1).

The synthesis and SAR of a series of arylsulfonylpiperazine inhibitors of 11beta-HSD1 are described. Optimization rapidly led to potent, selective, and orally bioavailable inhibitors demonstrating efficacy in a cynomolgus monkey ex vivo enzyme inhibition model.

Optimization of novel di-substituted cyclohexylbenzamide derivatives as potent 11 beta-HSD1 inhibitors.

Novel 4,4-disubstituted cyclohexylbenzamide inhibitors of 11beta-HSD1 were optimized to account for liabilities relating to in vitro pharmacokinetics, cytotoxicity and protein-related shifts in potency. A representative compound showing favorable in vivo pharmacokinetics was found to be an efficacious inhibitor of 11beta-HSD1 in a rat pharmacodynamic model (ED(50)=10mg/kg).

Distinctive molecular inhibition mechanisms for selective inhibitors of human 11beta-hydroxysteroid dehydrogenase type 1.

11beta-hydroxysteroid dehydrogenase type 1 (11beta-HSD1) catalyzes the NADPH dependent interconversion of inactive cortisone to active cortisol. Excess 11beta-HSD1 or cortisol leads to insulin resistance and metabolic syndrome in animal models and in humans. Inhibiting 11beta-HSD1 activity signifies a promising therapeutic strategy in the treatment of Type 2 diabetes and related diseases. Herein, we report two highly potent and selective small molecule inhibitors of human 11beta-HSD1. While compound 1, a sulfonamide, functions as a simple substrate competitive inhibitor, compound 2, a triazole, shows the kinetic profile of a mixed inhibitor. Co-crystal structures reveal that both compounds occupy the 11beta-HSD1 catalytic site, but present distinct molecular interactions with the protein. Strikingly, compound 2 interacts much closer to the cofactor NADP+ and likely modifies its binding. Together, the structural and kinetic analyses demonstrate two distinctive molecular inhibition mechanisms, providing valuable information for future inhibitor design.

Discovery of novel, potent benzamide inhibitors of 11beta-hydroxysteroid dehydrogenase type 1 (11beta-HSD1) exhibiting oral activity in an enzyme inhibition ex vivo model.

We report the discovery of potent benzamide inhibitors of 11beta-hydroxysteroid dehydrogenase (11beta-HSD1). The optimization and correlation of in vitro and in vivo metabolic stability will be described. Through modifications to our initial lead 2, we discovered pyridyl compound 13. This compound has a favorable pharmacokinetic profile across three species and showed a dose-dependent decrease in adipose 11beta-HSD1 activity in a monkey ex vivo pharmacodynamic model.

An efficient and scalable one-pot double Michael addition-Dieckmann condensation for the synthesis of 4,4-disubstituted cyclohexane beta-keto esters.

A simple, scalable, and efficient one-pot methodology for the synthesis of 4,4-disubstituted cyclohexane beta-keto esters from benzylic nitriles or esters and methyl acrylate promoted by potassium tert-butoxide is described. The process relies on a tandem double Michael addition-Dieckmann condensation reaction, which results in the formation of three discrete carbon-carbon bonds in a single pot, including a quaternary center. The method allows for the convenient and rapid synthesis of a variety of 4-aryl-4-cyano-2-carbomethoxycyclohexanone and 4-aryl-2,4-biscarbomethoxycyclohexanone building blocks for use in natural products synthesis and medicinal chemistry.

Reactivity of Enol Carbonates with Ozone.

Several dienes of varying steric bulk containing an enol carbonate have been synthesized and reacted selectively with ozone at the isolated double bonds. Rate measurements have been made for ozonolysis in a series of substituted cyclohexenes to demonstrate the unusually slow reactivity of the enol carbonate. Proton and carbon NMR chemical shifts have been presented to show that the enol carbonate is not particularly electron deficient in its double bond. Calculation of partial charges from the Mulliken population analysis shows good correlation with the NMR data. The results suggest a carbonate association with ozone that slows the rate of carbon-carbon bond cleavage.