PROTAC-mediated NR4A1 degradation as a novel strategy for cancer immunotherapy

An effective cancer therapy requires killing cancer cells and targeting the tumor microenvironment (TME). Searching for molecules critical for multiple cell types in the TME, we identified NR4A1 as one such molecule that can maintain the immune suppressive TME. Here, we establish NR4A1 as a valid target for cancer immunotherapy and describe a first-of-its-kind proteolysis-targeting chimera (PROTAC, named NR-V04) against NR4A1. NR-V04 degrades NR4A1 within hours in vitro and exhibits long-lasting NR4A1 degradation in tumors with an excellent safety profile. NR-V04 inhibits and frequently eradicates established tumors. At the mechanistic level, NR-V04 induces the tumor-infiltrating (TI) B cells and effector memory CD8+ T (Tem) cells and reduces monocytic myeloid-derived suppressor cells (m-MDSC), all of which are known to be clinically relevant immune cell populations in human melanomas. Overall, NR-V04-mediated NR4A1 degradation holds promise for enhancing anticancer immune responses and offers a new avenue for treating various types of cancers such as melanoma.

Unleashing the Power of NR4A1 Degradation as a Novel Strategy for Cancer Immunotherapy

An effective cancer therapy requires both killing cancer cells and targeting tumor-promoting pathways or cell populations within the tumor microenvironment (TME). We purposely search for molecules that are critical for multiple tumor-promoting cell types and identified nuclear receptor subfamily 4 group A member 1 (NR4A1) as one such molecule. NR4A1 has been shown to promote the aggressiveness of cancer cells and maintain the immune suppressive TME. Using genetic and pharmacological approaches, we establish NR4A1 as a valid therapeutic target for cancer therapy. Importantly, we have developed the first-of-its kind proteolysis-targeting chimera (PROTAC, named NR-V04) against NR4A1. NR-V04 effectively degrades NR4A1 within hours of treatment in vitro and sustains for at least 4 days in vivo, exhibiting long-lasting NR4A1-degradation in tumors and an excellent safety profile. NR-V04 leads to robust tumor inhibition and sometimes eradication of established melanoma tumors. At the mechanistic level, we have identified an unexpected novel mechanism via significant induction of tumor-infiltrating (TI) B cells as well as an inhibition of monocytic myeloid derived suppressor cells (m-MDSC), two clinically relevant immune cell populations in human melanomas. Overall, NR-V04-mediated NR4A1 degradation holds promise for enhancing anti-cancer immune responses and offers a new avenue for treating various types of cancer.

Discovery of camphor-derived pyrazolones as 11β-hydroxysteroid dehydrogenase type 1 inhibitors

Starting from screening hit, (4S,7R)-1,7,8,8-tetramethyl-2-phenyl-1,2,4,5,6,7-hexahydro-4,7-methano-indazol-3-one (7), we optimized the potency and pharmacokinetic properties. This led to the identification of compounds with good in vivo activity in a mouse pharmacodynamic model of inhibition of 11βHSD1.

Identification of RO4597014, a Glucokinase Activator Studied in the Clinic for the Treatment of Type 2 Diabetes

To resolve the metabolite redox cycling associated with our earlier clinical compound 2, we carried out lead optimization of lead molecule 1. Compound 4 showed improved lipophilic ligand efficiency and demonstrated robust glucose lowering in diet-induced obese mice without a liability in predictive preclinical drug safety studies. Thus, it was selected as a clinical candidate and further studied in type 2 diabetic patients. Clinical data suggests no evidence of metabolite cycling, which is consistent with the preclinical profiling of metabolism.

Discovery, structure-activity relationships, pharmacokinetics, and efficacy of glucokinase activator (2R)-3-cyclopentyl-2-(4-methanesulfonylphenyl)-N-thiazol-2-yl-propionamide (RO0281675)

Glucokinase (GK) is a glucose sensor that couples glucose metabolism to insulin release. The important role of GK in maintaining glucose homeostasis is illustrated in patients with GK mutations. In this publication, identification of the hit molecule 1 and its SAR development, which led to the discovery of potent allosteric GK activators 9a and 21a, is described. Compound 21a (RO0281675) was used to validate the clinical relevance of targeting GK to treat type 2 diabetes.

Small Molecule Glucokinase Activators as Glucose Lowering Agents: A New Paradigm for Diabetes Therapy

Glucokinase (GK) is a molecular sensor that regulates glucose induced insulin secretion in pancreatic beta-cells and glucose homeostasis in the liver via catalysis of glucose to glucose-6-phosphate. The recent discovery and development of small molecule glucokinase activators represents a potentially important development for the management of type 2 diabetes. Since the discovery of the first orally active small molecule GK activator RO0281675, a number of research groups have reported the identification of potent activators. In this review, the biological significance of GK in whole body glucose homeostasis is briefly described coupled with the recent progress regarding the identification of novel small molecule GK activators.

Identification of a novel class of orally active pyrimido[5,4-3][1,2,4]triazine-5,7-diamine-based hypoglycemic agents with protein tyrosine phosphatase inhibitory activity

A novel series of orally active pyrimido[5,4-3][1,2,4]triazine-5,7-diamine-based hypoglycemic agents have been identified. These compounds show non-selective inhibitory properties against a panel of protein tyrosine phosphatases including PTP1B. Compounds 12 and 13 display oral glucose lowering effects in ob/ob mice.

Allosteric activators of glucokinase: potential role in diabetes therapy

Glucokinase (GK) plays a key role in whole-body glucose homeostasis by catalyzing the phosphorylation of glucose in cells that express this enzyme, such as pancreatic beta cells and hepatocytes. We describe a class of antidiabetic agents that act as nonessential, mixed-type GK activators (GKAs) that increase the glucose affinity and maximum velocity (Vmax) of GK. GKAs augment both hepatic glucose metabolism and glucose-induced insulin secretion from isolated rodent pancreatic islets, consistent with the expression and function of GK in both cell types. In several rodent models of type 2 diabetes mellitus, GKAs lowered blood glucose levels, improved the results of glucose tolerance tests, and increased hepatic glucose uptake. These findings may lead to the development of new drug therapies for diabetes.

Optimization of the beta-aminoester class of factor Xa inhibitors. Part 1: P(4) and side-chain modifications for improved in vitro potency

A systematic modification of the C(3) side-chain of the beta-aminoester class of factor Xa inhibitors and a survey of P(4) variations is described. These changes have resulted in the identification of sub-nanomolar inhibitors with improved selectivity versus related proteases. Coagulation parameters (i.e., APTT doubling concentrations) are also improved.

Optimization of the beta-aminoester class of factor Xa inhibitors. Part 2: Identification of FXV673 as a potent and selective inhibitor with excellent In vivo anticoagulant activity

Further optimization of the beta-aminoester class of factor Xa (fXa) inhibitors is described culminating in the identification of 9c (FXV673), a potent and selective factor Xa inhibitor with excellent in vivo anticoagulant activity. An X-ray structure of FXV673 bound to human fXa is also presented. Based on its selectivity, potent in vivo activity and favorable pre-clinical safety profile, FXV673 was selected for further development and is currently undergoing clinical trials.

Identification and initial structure-activity relationships of a novel class of nonpeptide inhibitors of blood coagulation factor Xa

The discovery and some of the basic structure-activity relationships of a series of novel nonpeptide inhibitors of blood coagulation Factor Xa is described. These inhibitors are functionalized beta-alanines, exemplified by 2a. Docking experiments placing 2a in the active site of Factor Xa implied that the most expeditious route to enhancing in vitro potency was to modify the group occupying the S3 site of the enzyme. Increasing the hydrophobic contacts between the inhibitor and the enzyme in this region led to 8, which has served as the prototype for this series. In addition, an enantioselective synthesis of these substituted beta-alanines was also developed.

Functional analysis of the Pseudomonas aeruginosa autoinducer PAI

A series of structural analogs of the Pseudomonas aeruginosa autoinducer [PAI, N-3-oxo-dodecanoyl homoserine lactone] were obtained and tested for their ability to act as autoinducers in stimulating the expression of the gene for elastase (lasB) by measuring beta-galactosidase production from a lasB-lacZ gene fusion in the presence of the transcriptional activator LasR. The data suggest that the length of the acyl side chain of the autoinducer molecule is the most critical factor for activity. Replacement of the ring O by S in the homoserine lactone moiety can be tolerated. Tritium-labelled PAI ([3H]PAI) was synthesized and used to demonstrate the association of [3H]PAI with cells overexpressing LasR. The PAI analogs were also tested for their ability to compete with [3H]PAI for binding of LasR. Results from the competition assays suggest that once again the length of the acyl side chain appears to be crucial for antagonist activity. The presence of the 3-oxo moiety also plays a significant role in binding since analogs which lacked this moiety were much less effective in blocking binding of [3H]PAI. All analogs demonstrating competition with PAI in binding to LasR also exhibited the ability to activate lasB expression, suggesting that they are functional analogs of PAI.

Bilateral acetylsulfapyridine nephrolithiasis associated with chronic sulfasalazine therapy

We report on formation of bilateral renal calculi secondary to sulfasalazine therapy for juvenile rheumatoid arthritis. The condition was successfully treated with extracorporeal shock wave lithotripsy. Analysis of the fragments with thin layer chromatography and nuclear magnetic resonance revealed acetylsulfapyridine, a metabolite of sulfasalazine.