Design and optimization of renin inhibitors: Orally bioavailable alkyl amines

Structure-based drug design led to the identification of a novel class of potent, low MW alkylamine renin inhibitors. Oral administration of lead compound 21l, with MW of 508 and IC₅₀ of 0.47 nM, caused a sustained reduction in mean arterial blood pressure in a double transgenic rat model of hypertension.     

Optimization of a series of potent,selective and orally bioavailable SYK inhibitors

Spleen tyrosine kinase (SYK) is a non-receptor cytosolic kinase. Due to its pivotal role in B cell receptor and Fc-receptor signaling, inhibition of SYK has been targeted in a variety of disease areas. Herein, we report the optimization of a series of potent and selective SYK inhibitors, focusing on improving metabolic stability, pharmacokinetics and hERG inhibition. As a result, we identified 30, which exhibited no hERG activity but unfortunately was poorly absorbed in rats and mice. We also identified a SYK chemical probe, 17, which exhibits excellent potency at SYK, and an adequate rodent PK profile to support in vivo efficacy/PD studies.     

Acyclic, orally bioavailable ketone-based cathepsin K inhibitors

Starting from a potent ketone-based inhibitor with poor drug properties, incorporation of P(2)-P(3) elements from a ketoamide-based inhibitor led to the identification of a hybrid series of ketone-based cathepsin K inhibitors with better oral bioavailability than the starting ketone.     

New classes of potent and bioavailable human renin inhibitors

New classes of de novo designed renin inhibitors are reported. Some of these compounds display excellent in vitro and in vivo activities toward human renin in a TGR model. The synthesis of these new types of mono- and bicyclic scaffolds are reported, and properties of selected compounds discussed.     

Discovery of an orally bioavailable alkyl oxadiazole beta3 adrenergic receptor agonist

5-n-Pentyl oxadiazole substituted benzenesulfonamide 8 is a potent and selective beta3 adrenergic receptor agonist (beta3 EC50 = 23 nM, beta1 IC50 = 3000 nM, beta2 IC50 = 3000 nM). The compound has high oral bioavailability in dogs (62%) and rats (36%) and is among the most orally bioavailable beta3 adrenergic receptor agonists reported to date.     

Potent and orally bioavailable noncysteine-containing inhibitors of protein farnesyltransferase.

Potent and orally bioavailable nonthiol-containing inhibitors of protein farnesyltransferase are described. Oral bioavailability was achieved by replacement of the pyridyl ether moiety of 1 with a 2-substituted furan ether to give 4. Potency was regained with 2,5-disubstituted furan ethers while maintaining the bioavailability inherent in 4. p-Chlorophenylfuran ether 24 is 0.7 nM in vitro (FTase) and is 32% bioavailable in the mouse, 30% bioavailable in rats, and 21% bioavailable in dogs.     

Arylphthalazines as potent,and orally bioavailable inhibitors of VEGFR-2

A series of arylphthalazine derivatives were synthesized and evaluated as antagonists of VEGF receptor II (VEGFR-2). IM-094482 57, which was prepared in two steps from commercially available starting materials, was found to be a potent inhibitor of VEGFR-2 in enzymatic, cellular and mitogenic assays (comparable activity to ZD-6474). Additionally, 57 inhibited the related receptor, VEGF receptor I (VEGFR-1), and showed excellent exposure when dosed orally to female CD-1 mice.     

Bicyclic pyridones as potent, efficacious and orally bioavailable thrombin inhibitors

A new class of conformationally constrained thrombin inhibitors is described. These compounds contain a unique bicyclic pyridone scaffold which serves as a P3P2 dipeptide surrogate. The synthesis and antithrombotic activity of these inhibitors is reported.     

Selective and orally bioavailable phenylglycine tissue factor/factor VIIa inhibitors

We describe the structure-based design and synthesis of highly potent, orally bioavailable tissue factor/factor VIIa inhibitors which interfere with the coagulation cascade by selective inhibition of the extrinsic pathway.     

Imidazole pyrimidine amides as potent, orally bioavailable cyclin-dependent kinase inhibitors

The development of a novel series of imidazole pyrimidine amides as cyclin-dependent kinase (CDK) inhibitors is described. The series was found to have much improved CDK2 inhibition and potent in vitro anti-proliferative effects against cancer cell lines. Control of overall lipophilicity was important to achieve good in vitro potency along with acceptable physiochemical properties and margins against inhibition of both CYP isoforms and the hERG potassium ion channel. A compound with an attractive overall balance of properties was profiled in vivo and possessed suitable physiochemical and pharmacokinetic profiles for oral dosing.     

Alkylsulfonamide-containing quinazoline derivatives as potent and orally bioavailable PI3Ks inhibitors

Phosphoinositide 3-kinases (PI3Ks) are regarded as promising targets for treatment of various cancers due to their roles in regulating cell proliferation, differentiation, migration, and survival. Here we report our efforts to develop potent and orally bioavailable PI3K inhibitors for the treatment of cancers. The alkylsulfonamide-containing quinazoline derivatives A1–A18 significantly inhibited PI3Kα, and cell proliferation among HCT-116, MCF-7 and SU-DHL-6 cell lines. The optimal compound A1 displayed potent inhibitory activity against PI3Kα (IC₅₀ = 4.5 nM), PI3Kβ (IC₅₀ = 4.5 nM), PI3Kγ (IC₅₀ = 4.5 nM), PI3Kδ (IC₅₀ = 4.5 nM) and significantly inhibited the growth of HCT-116, MCF-7 and SU-DHL-6 cell lines with IC₅₀ values of 0.82 µM, 0.99 µM and 0.19 µM, respectively. Western blot analysis demonstrated A1 significantly suppressed the phosphorylation of AKT^S473 in a dose-dependent manner. Furthermore, A1 could markedly inhibit cancer growth at the dose of 25 mg/kg in nude mouse HCT-116 xenograft model in vivo without causing significant weight loss or toxicity.     

Novel, potent, selective, and orally bioavailable human betaII-tryptase inhibitors

The synthesis of novel [1,2,4]oxadiazoles and their structure-activity relationship (SAR) for the inhibition of tryptase and related serine proteases is presented. Elaboration of the P'-side afforded potent, selective, and orally bioavailable tryptase inhibitors.     

Potent,orally bioavailable,liver-selective stearoyl-CoA desaturase (SCD) inhibitors

Two structurally distinct series of SCD (Δ9 desaturase) inhibitors (1 and 2) have been previously reported by our group. In the present work, we merged the structural features of the two series. This led to the discovery of compound 5b (CVT-12,012) which is highly potent in a human cell-based (HEPG2) SCD assay (IC₅₀ = 6 nM). This compound has 78% oral bioavailability in rats and is preferentially distributed into liver (76 times vs plasma) with relatively low brain penetration. In a five-day study (sucrose fed rats) compound 5b significantly reduced SCD activity in a dose-dependent manner as determined by GC analysis of fatty acid composition in plasma and liver, and significantly reduced liver triglycerides versus the control group (～50%).     

Discovery of orally bioavailable imidazo[1,2-a]pyrazine-based Aurora kinase inhibitors

We report a series of potent imidazo[1,2-a]pyrazine-based Aurora kinase inhibitors. Optimization of the solvent accessible 8-position led to improvements in both oral bioavailability and off-target kinase inhibition. Compound 25 demonstrates anti-tumor activity in an A2780 ovarian tumor xenograft model.     

Lead optimization of purine based orally bioavailable Mps1 (TTK) inhibitors

Efforts to optimize biological activity, novelty, selectivity and oral bioavailability of Mps1 inhibitors, from a purine based lead MPI-0479605, are described in this Letter. Mps1 biochemical activity and cytotoxicity in HCT-116 cell line were improved. On-target activity confirmation via mechanism based G2/M escape assay was demonstrated. Physico-chemical and ADME properties were optimized to improve oral bioavailability in mouse.     

Design and evaluation of dihydroisoquinolines as potent and orally bioavailable human cytomegalovirus inhibitors

Following the identification of first pass metabolism issues with our recently described anti-HCMV compounds, the naphthyridines and isoquinolines, we have designed a class of novel metabolically stable and orally bioavailable anti-HCMV agents, the dihydroisoquinolines.     

Design, synthesis and testing of amino-bicycloaryl based orally bioavailable thrombin inhibitors.

Replacement of the highly basic benzamidine moiety with moderate basic amino-bicycloaryl moieties in a series of thrombin inhibitors related to NAPAMP provided potent enzyme inhibition and significant improvements in membrane transport and oral bioavailability.     

Development of 2-pyrrolidinyl-N-methyl pyrimidones as potent and orally bioavailable HIV integrase inhibitors

A series of 2-pyrrolidinyl-N-methyl pyrimidones HIV integrase inhibitors has been explored leading to the identification of derivative 13, which showed high activity at inhibiting viral replication in cell culture, favorable pharmacokinetic profile in two preclinical species, and an attractive profile against a panel of HIV-integrase mutants.     

Cyanoguanidine-based lactam derivatives as a novel class of orally bioavailable factor Xa inhibitors

The N,N′-disubstituted cyanoguanidine is an excellent bioisostere of the thiourea and ketene aminal functional groups. We report the design and synthesis of a novel class of cyanoguanidine-based lactam derivatives as potent and orally active FXa inhibitors. The SAR studies led to the discovery of compound 4 (BMS-269223, K_i = 6.5 nM, EC_2xPT = 32 μM) as a selective, orally bioavailable FXa inhibitor with an excellent in vitro liability profile, favorable pharmacokinetics and pharmacodynamics in animal models. The X-ray crystal structure of 4 bound in FXa is presented and key ligand–protein interactions are discussed.     

Biaryl ether retrohydroxamates as potent, long-lived, orally bioavailable MMP inhibitors.

A novel series of biaryl ether reverse hydroxamate MMP inhibitors has been developed. These compounds are potent MMP-2 inhibitors with limited activity against MMP-1. Select members of this series exhibit excellent pharmacokinetic properties with long elimination half-lives (7 h) and high oral bioavailability (100%).