Ellen Van der Aar

Preclinical Characterization of GLPG0634, a Selective Inhibitor of JAK1, for the Treatment of Inflammatory Diseases

The JAKs receive continued interest as therapeutic targets for autoimmune, inflammatory, and oncological diseases. JAKs play critical roles in the development and biology of the hematopoietic system, as evidenced by mouse and human genetics. JAK1 is critical for the signal transduction of many type I and type II inflammatory cytokine receptors. In a search for JAK small molecule inhibitors, GLPG0634 was identified as a lead compound belonging to a novel class of JAK inhibitors. It displayed a JAK1/JAK2 inhibitor profile in biochemical assays, but subsequent studies in cellular and whole blood assays revealed a selectivity of ∼30-fold for JAK1- over JAK2-dependent signaling. GLPG0634 dose-dependently inhibited Th1 and Th2 differentiation and to a lesser extent the differentiation of Th17 cells in vitro. GLPG0634 was well exposed in rodents upon oral dosing, and exposure levels correlated with repression of Mx2 expression in leukocytes. Oral dosing of GLPG0634 in a therapeutic set-up in a collagen-induced arthritis model in rodents resulted in a significant dose-dependent reduction of the disease progression. Paw swelling, bone and cartilage degradation, and levels of inflammatory cytokines were reduced by GLPG0634 treatment. Efficacy of GLPG0634 in the collagen-induced arthritis models was comparable to the results obtained with etanercept. In conclusion, the JAK1 selective inhibitor GLPG0634 is a promising novel therapeutic with potential for oral treatment of rheumatoid arthritis and possibly other immune-inflammatory diseases.

Discovery and Optimization of an Azetidine Chemical Series As a Free Fatty Acid Receptor 2 (FFA2) Antagonist: From Hit to Clinic

FFA2, also called GPR43, is a G-protein coupled receptor for short chain fatty acids which is involved in the mediation of inflammatory responses. A class of azetidines was developed as potent FFA2 antagonists. Multiparametric optimization of early hits with moderate potency and suboptimal ADME properties led to the identification of several compounds with nanomolar potency on the receptor combined with excellent pharmacokinetic (PK) parameters. The most advanced compound, 4-[[(R)-1-(benzo[b]thiophene-3-carbonyl)-2-methyl-azetidine-2-carbonyl]-(3-chloro-benzyl)-amino]-butyric acid 99 (GLPG0974), is able to inhibit acetate-induced neutrophil migration strongly in vitro and demonstrated ability to inhibit a neutrophil-based pharmacodynamic (PD) marker, CD11b activation-specific epitope [AE], in a human whole blood assay. All together, these data supported the progression of 99 toward next phases, becoming the first FFA2 antagonist to reach the clinic.

Triazolopyridines as Selective JAK1 Inhibitors: From Hit Identification to GLPG0634

Janus kinases (JAK1, JAK2, JAK3, and TYK2) are involved in the signaling of multiple cytokines important in cellular function. Blockade of the JAK-STAT pathway with a small molecule has been shown to provide therapeutic immunomodulation. Having identified JAK1 as a possible new target for arthritis at Galapagos, the compound library was screened against JAK1, resulting in the identification of a triazolopyridine-based series of inhibitors represented by 3. Optimization within this chemical series led to identification of GLPG0634 (65, filgotinib), a selective JAK1 inhibitor currently in phase 2B development for RA and phase 2A development for Crohns disease (CD).

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.

Discovery of 2-[[2-Ethyl-6-[4-[2-(3-hydroxyazetidin-1-yl)-2-oxoethyl]piperazin-1-yl]-8-methylimidazo[1,2-a]pyridin-3-yl]methylamino]-4-(4-fluorophenyl)thiazole-5-carbonitrile (GLPG1690), a First-in-Class Autotaxin Inhibitor Undergoing Clinical Evaluation for the Treatment of Idiopathic Pulmonary Fibrosis

Autotaxin is a circulating enzyme with a major role in the production of lysophosphatic acid (LPA) species in blood. A role for the autotaxin/LPA axis has been suggested in many disease areas including pulmonary fibrosis. Structural modifications of the known autotaxin inhibitor lead compound 1, to attenuate hERG inhibition, remove CYP3A4 time-dependent inhibition, and improve pharmacokinetic properties, led to the identification of clinical candidate GLPG1690 (11). Compound 11 was able to cause a sustained reduction of LPA levels in plasma in vivo and was shown to be efficacious in a bleomycin-induced pulmonary fibrosis model in mice and in reducing extracellular matrix deposition in the lung while also reducing LPA 18:2 content in bronchoalveolar lavage fluid. Compound 11 is currently being evaluated in an exploratory phase 2a study in idiopathic pulmonary fibrosis patients.

Safety, tolerability, pharmacokinetics, and pharmacodynamics of GLPG1690, a novel autotaxin inhibitor, to treat idiopathic pulmonary fibrosis (FLORA): a phase 2a randomised placebo-controlled trial

BACKGROUND Idiopathic pulmonary fibrosis (IPF) causes irreversible loss of lung function. People with IPF have increased concentrations of autotaxin in lung tissue and lysophosphatidic acid (LPA) in bronchoalveolar lavage fluid and exhaled condensate. GLPG1690 (Galapagos, Mechelen, Belgium) is a novel, potent, selective autotaxin inhibitor with good oral exposure. We explored the effects of GLPG1690 in patients with IPF. METHODS This was a randomised, double-blind, placebo-controlled phase 2a study done in 17 centres in Italy, Ukraine and the UK. Eligible patients were aged 40 years or older, non-smokers, not taking pirfenidone or nintedanib, and had a centrally confirmed diagnosis of IPF. We used a computer-generated randomisation schedule to assign patients 1:3 to receive placebo or 600 mg oral GLPG1690 once daily for 12 weeks. The primary outcomes were safety (adverse events), tolerability, pharmacokinetics, and pharmacodynamics. Spirometry was assessed as a secondary outcome. This trial is registered with ClinicalTrials.gov, number NCT02738801. FINDINGS Between March 24, 2016, and May 2, 2017, 72 patients were screened., of whom 49 were ineligible and 23 were enrolled in eight centres (six in Ukraine and two in the UK). Six patients were assigned to receive placebo and 17 to receive GLPG1690. 20 patients completed the study after one in each group discontinued because of adverse events and one in the GLPG1690 group withdrew consent. Four (67%) patients in the placebo group and 11 (65%) in the GLPG1690 group had treatment-emergent adverse events, most of which were mild to moderate. The most frequent events in the GLPG1690 group were infections and infestations (ten events) and respiratory, thoracic, and mediastinal disorders (eight events) with no apparent differences from the placebo group. Two (12%) patients in the GLPG1690 group had events that were judged to be related to treatment. Serious adverse events were seen in two patients in the placebo group (one had a urinary tract infection, acute kidney injury, and lower respiratory tract infection and the other had atrioventricular block, second degree) and one in the GLPG1690 group (cholangiocarcinoma that resulted in discontinuation of treatment). No patients died. The pharmacokinetic and pharmacodynamic profiles of GLPG1690 were similar to those previously shown in healthy controls. LPA C18:2 concentrations in plasma were consistently decreased. Mean change from baseline in forced vital capacity at week 12 was 25 mL (95% CI -75 to 124) for GLPG1690 and -70 mL (-208 to 68 mL) for placebo. INTERPRETATION Our findings support further development of GLPG1690 as a novel treatment for IPF. FUNDING Galapagos.

Discovery, Structure–Activity Relationship, and Binding Mode of an Imidazo[1,2-a]pyridine Series of Autotaxin Inhibitors

Autotaxin (ATX) is a secreted enzyme playing a major role in the production of lysophosphatidic acid (LPA) in blood through hydrolysis of lysophosphatidyl choline (LPC). The ATX-LPA signaling axis arouses a high interest in the drug discovery industry as it has been implicated in several diseases including cancer, fibrotic diseases, and inflammation, among others. An imidazo[1,2-a]pyridine series of ATX inhibitors was identified out of a high-throughput screening (HTS). A cocrystal structure with one of these compounds and ATX revealed a novel binding mode with occupancy of the hydrophobic pocket and channel of ATX but no interaction with zinc ions of the catalytic site. Exploration of the structure-activity relationship led to compounds displaying high activity in biochemical and plasma assays, exemplified by compound 40. Compound 40 was also able to decrease the plasma LPA levels upon oral administration to rats.

Discovery of N-(3-Carbamoyl-5,5,7,7-tetramethyl-5,7-dihydro-4H-thieno[2,3-c]pyran-2-yl)-lH-pyrazole-5-carboxamide (GLPG1837), a Novel Potentiator Which Can Open Class III Mutant Cystic Fibrosis Transmembrane Conductance Regulator (CFTR) Channels to a High Extent

Cystic fibrosis (CF) is caused by mutations in the gene for the cystic fibrosis transmembrane conductance regulator (CFTR). With the discovery of Ivacaftor and Orkambi, it has been shown that CFTR function can be partially restored by administering one or more small molecules. These molecules aim at either enhancing the amount of CFTR on the cell surface (correctors) or at improving the gating function of the CFTR channel (potentiators). Here we describe the discovery of a novel potentiator GLPG1837, which shows enhanced efficacy on CFTR mutants harboring class III mutations compared to Ivacaftor, the first marketed potentiator. The optimization of potency, efficacy, and pharmacokinetic profile will be described.

Abstract 1753: GLPG1790: The first Ephrin (EPH) receptor tyrosine kinase inhibitor for the treatment of triple negative breast cancer

Receptor tyrosine kinases define a clinically relevant class of targets in the field of cancer. Here we report the discovery of a pre-clinical drug candidate directed against the EPH receptor family. Members of this family of receptor tyrosine kinases are over-expressed in diverse cancer types. GLPG1790 is a small molecule, nanomolar inhibitor of various EPH receptors kinases. The compound displayed a remarkable efficacy by once-daily oral administration in a mouse EPHA2 expressing xenograft model (MDA-MB-231). A rapid dose-dependent reduction of tumor growth was achieved, with full inhibition at the oral dose of 30 mg/kg/d. GLPG1790 efficacy at this dose was similar to that of Paclitaxel administered at its maximum tolerated dose. A series of experiments was initiated to confirm the mechanism of action of this compound. GLPG1790 inhibits human EPHA2 kinase activity with an IC 50 of 11 nM in a biochemical assay. In the human MDA-MB-231 breast cancer cell line, that expresses a high level of EPHA2 protein, GLPG1790 inhibits receptor phosphorylation with an IC 50 of 260 nM, and anchorage-independent growth with similar potency. In addition, in vivo target engagement was demonstrated in the mouse MDA-MB-231 xenograft model. GLPG1790 inhibited EPHA2 receptor phosphorylation after single oral administration of 30 and 100 mg/kg doses. The extent of the effects observed on EPHA2 phosphorylation correlated with intra-tumoral GLPG1790 concentration. Moreover, the MAPK pathway, known to be a major driver of proliferation of this cell line, was inhibited both in in vitro cellular assays and in xenograft target engagement studies. Flow cytometric analyses revealed a cell cycle arrest at the G0/G1 phase for MDA-MB-231 cells treated with GLPG1790. EPHA2 knock-down-based experiments further support the EPH-driven mode of action of GLPG1790. All together these data stimulate the development of GLPG1790 in triple negative breast cancer. This novel mechanism of action is under investigation in other cancer types overexpressing EPH9s (melanoma, pancreatic, ovarian, prostatic and colorectal cancers). Citation Format: Philippe Pujuguet, Filip Beirinckx, Carole Delachaume, Jacques Huck, Ellen Van der Aar, Reginald Brys, Luc Van Rompaey, Piet Wigerinck, Laurent Saniere. GLPG1790: The first Ephrin (EPH) receptor tyrosine kinase inhibitor for the treatment of triple negative breast cancer. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 1753. doi:10.1158/1538-7445.AM2014-1753