Discovery of GLPG2737, a Potent Type 2 Corrector of CFTR for the Treatment of Cystic Fibrosis in Combination with a Potentiator and a Type 1 Co-corrector.

Cystic fibrosis (CF) is caused by mutations in the CF transmembrane conductance regulator (CFTR) protein. This epithelial anion channel regulates the active transport of chloride and bicarbonate ions across membranes. Mutations result in reduced surface expression of CFTR channels with impaired functionality. Correctors are small molecules that support the trafficking of CFTR to increase its membrane expression. Such correctors can have different mechanisms of action. Combinations may result in a further improved therapeutic benefit. We describe the identification and optimization of a new pyrazolol3,4-bl pyridine-6-carboxylic acid series with high potency and efficacy in rescuing CFTR from the cell surface. Investigations showed that carboxylic acid group replacement with acylsulfonamides and acylsulfonylureas improved ADMET and PK properties, leading to the discovery of the structurally novel co-corrector GLPG2737. The addition of GLPG2737 to the combination of the potentiator GLPG1837 and C1 corrector 4 led to an 8-fold increase in the F508del CFTR activity.

Discovery of Clinical Candidate GLPG3970: A Potent and Selective Dual SIK2/SIK3 Inhibitor for the Treatment of Autoimmune and Inflammatory Diseases.

The salt-inducible kinases (SIKs) SIK1, SIK2, and SIK3 belong to the adenosine monophosphate-activated protein kinase (AMPK) family of serine/threonine kinases. SIK inhibition represents a new therapeutic approach modulating pro-inflammatory and immunoregulatory pathways that holds potential for the treatment of inflammatory diseases. Here, we describe the identification of GLPG3970 (32), a first-in-class dual SIK2/SIK3 inhibitor with selectivity against SIK1 (IC50 of 282.8 nM on SIK1, 7.8 nM on SIK2 and 3.8 nM on SIK3). We outline efforts made to increase selectivity against SIK1 and improve CYP time-dependent inhibition properties through the structure-activity relationship. The dual activity of 32 in modulating the pro-inflammatory cytokine TNFα and the immunoregulatory cytokine IL-10 is demonstrated in vitro in human primary myeloid cells and human whole blood, and in vivo in mice stimulated with lipopolysaccharide. Compound 32 shows dose-dependent activity in disease-relevant mouse pharmacological models.

Discovery of GLPG1972/S201086, a Potent, Selective, and Orally Bioavailable ADAMTS-5 Inhibitor for the Treatment of Osteoarthritis.

There are currently no approved disease-modifying osteoarthritis (OA) drugs (DMOADs). The aggrecanase ADAMTS-5 is key in the degradation of human aggrecan (AGC), a component of cartilage. Therefore, ADAMTS-5 is a promising target for the identification of DMOADs. We describe the discovery of GLPG1972/S201086, a potent and selective ADAMTS-5 inhibitor obtained by optimization of a promising hydantoin series following an HTS. Biochemical activity against rat and human ADAMTS-5 was assessed via a fluorescence-based assay. ADAMTS-5 inhibitory activity was confirmed with human aggrecan using an AGC ELISA. The most promising compounds were selected based on reduction of glycosaminoglycan release after interleukin-1 stimulation in mouse cartilage explants and led to the discovery of GLPG1972/S201086. The anticatabolic activity was confirmed in mouse cartilage explants (IC50 < 1.5 µM). The cocrystal structure of GLPG1972/S201086 with human recombinant ADAMTS-5 is discussed. GLPG1972/S201086 has been investigated in a phase 2 clinical study in patients with knee OA (NCT03595618).

New potent calcimimetics: I. Discovery of a series of novel trisubstituted ureas.

Starting from Fendiline and R-568, we identified a novel series of urea compounds as positive allosteric modulators of the calcium sensing receptor (CaSR), as part of a program to identify novel therapeutics for secondary hyperparathyroidism. Initially identified disubstituted ureas were converted to trisubstituted urea lead 20e, which was further modified to increase in vivo potency. Replacing a carbomethoxy substituent by various bioisosteres led to compound 46 which exhibited potent in vitro and in vivo activity after oral administration.

New potent calcimimetics: II. Discovery of benzothiazole trisubstituted ureas.

Following the identification of trisubstituted ureas as a promising new chemical series of allosteric modulators of the calcium sensing receptor (CaSR), we further explored the SAR around the urea substitution, leading to the discovery of benzothiazole urea compound 13. This compound is a potent calcimimetic with an EC50=20 nM (luciferase assay). Evaluated in an in vivo model of chronic renal failure (short term and long term in 5/6 nephrectomized rats), benzothiazole urea 13 significantly decreased PTH levels after oral administration while keeping calcemia within the normal range.

Identification of a 4-(hydroxymethyl)diarylhydantoin as a selective androgen receptor modulator.

Structural modification performed on a 4-methyl-4-(4-hydroxyphenyl)hydantoin series is described which resulted in the development of a new series of 4-(hydroxymethyl)diarylhydantoin analogues as potent, partial agonists of the human androgen receptor. This led to the identification of (S)-(-)-4-(4-(hydroxymethyl)-3-methyl-2,5-dioxo-4-phenylimidazolidin-1-yl)-2-(trifluoromethyl)benzonitrile ((S)-(-)-18a, GLPG0492) evaluated in vivo in a classical model of orchidectomized rat. In this model, (-)-18a exhibited anabolic activity on muscle, strongly dissociated from the androgenic activity on prostate after oral dosing. (-)-18a has very good pharmacokinetic properties, including bioavailability in rat (F > 50%), and is currently under evaluation in phase I clinical trials.