FIELD OF THE INVENTION The present invention relates to novel pyridazines, processes for their preparation, pharma ceutical compositions containing them and their use in therapy, particularly in the treat ment and/or prevention of diseases and disorders mediated by Autotaxin.

BACKGROUND OF THE INVENTION

Autotaxin (ATX; ENPP2) is a secreted enzyme responsible for hydrolysing lysophosphati- dylcholine (LPC) to the bioactive lipid lysophosphatidic acid (LPA) through its lysophos- pholipase D activity. In turn, LPA exerts its effects by interacting with six GPCRs (LPA Receptors 1-6, LPARl-6) (Houben AJ, 2011). ATX-LPA signalling has been implicated for example in angiogenesis, chronic inflammation, autoimmune diseases, fibrotic dis eases, cancer progression and tumor metastasis. For example, LPA, acting on LPARl, in duces lung fibroblast migration, proliferation and differentiation; modulates epithelial and endothelial barrier function; and promotes lung epithelial cell apoptosis (Budd, 2013). ATX inhibition, LPARl gene deletion and selective LPARl antagonists have been shown to be effective in pre-clinical models of fibrosis of the lung and skin (Tager AM, 2008; Swaney J, 2010, Casetelino FV, 2016).

In Idiopathic Pulmonary Fibrosis (IPF) patients, LPA levels in bronchoalveolar lavage fluid are increased (Tager et al ., 2008, Nat. Med.) and increased concentrations of ATX were detected in human fibrotic lung tissue. (Oikonomou et al. , 2012, AJRCMB). LPA levels are elevated in the exhaled breath condensate of IPF subjects (Montesi et al.,

2014 BMCPM), and LPC is increased 2-fold in serum of stable IPF patients

(Rindlisbacher et al., 2018, Resp. Res.).

Therefore, increased ATX levels and/or increased levels of LPA, altered LPA receptor ex pression, and altered responses to LPA may affect a number of pathophysiological condi- tions related to ATX-LPA signaling.

Interstitial Lung Diseases (ILDs) are characterized by inflammation and fibrosis of the in- terstitium, the tissue and space between the air sacs of the lung (du Bois, Nat. Rev. Drug Discov. 2010, 9, 129-140). An ILD may occur when an injury to the lungs triggers an ab normal healing response. ILDs thus also include Progressive Fibrosing Interstitial Lung Diseases (PFILDs) wherein the response to lung injury becomes progressive, self-sustain ing and independent of the original clinical association or trigger. The most prominent PF- ILDs are Idiopathic Pulmonary Fibrosis (IPF) and Systemic Sclerosis-ILD (SSc-ILD).

IPF is a chronic fibrotic irreversible and ultimately fatal lung disease characterized by a progressive fibrosis in the interstitium in the lung, leading to a decreasing lung volume and progressive pulmonary insufficiency. IPF is also characterized by a specific histopatho logic pattern known as usual interstitial pneumonia (UIP) (Raghu et al , Am. J. Respir. Crit. Care Med. 183: 788-824.).

Systemic Sclerosis (SSc) also called scleroderma is an immune-mediated rheumatic dis ease of complex aetiology. It is a multi-organ, heterogenic disease characterized by exten sive fibrosis, vasculopathy and autoantibodies against various cellular antigens with high mortality. It is a rare disorder, an orphan disease with high unmet medical need. The early clinical signs of SSc can be varied. Raynaud’s phenomenon and gastro-oesophageal reflux are often present early in the disease (Rongioletti F, et al., J Eur Acad Dermatol Venereol 2015; 29: 2399-404). Some patients present with inflammatory skin disease, puffy and swollen fingers, musculoskeletal inflammation, or constitutional manifestations such as fa tigue. Excess collagen deposition in the skin of patients makes the skin thick and tough. In some patients, organ-based manifestations of the disease, like lung fibrosis, pulmonary arterial hypertension, renal failure or gastrointestinal complication is observed. In addition, one of the most common manifestations of immune involvement is the presence of abnor mal levels of autoimmune antibodies to the nucleus of one’s own cells (anti-nuclear anti bodies or ANA) that are seen in nearly everyone with SSc (Guiducci S et al., Isr Med As- soc J 2016; 18: 141-43). ILD and pulmonary arterial hypertension (PAH) are the most fre quent causes of death in patients of SSc (Tyndall AJ et al. Ann Rheum Dis 2010; 69:

1809-15).

SSc patients are classified into two major disease subsets: diffuse cutaneous systemic scle rosis, and limited cutaneous systemic sclerosis (LeRoy EC, et al., J Rheumatol 1988;

15:202-5). Three clinical features— excessive fibrosis (scarring), vasculopathy, and auto immunity— appear to underlie the processes that result in the different manifestations that characterize SSc. SSc is currently considered as a manifestation of dysregulated or dys functional repair of connective tissue to injury (Denton CP et al ., Lancet 2017; 390: 1685- 99).

It is therefore desirable to provide potent ATX inhibitors.

ATX inhibitors of various structural classes are reviewed in D. Castagna et al.

(J.Med.Chem. 2016, 59, 5604-5621). WO2014/139882 discloses compounds that are in hibitors of ATX, having the generalized structural formula

Example 2 therein is further disclosed in N. Desroy, et al (J.Med.Chem. 2017, 60, 3580- 3590 as example 11) as a first-in-class ATX inhibitor undergoing clinical evaluation for the treatment of idiopathic pulmonary fibrosis. In C. Kuttruff, et al. (ACS Med. Chem. Lett. 2017, 8, 1252-1257) ATX inhibitor BI-2545 (example 19) is disclosed that signifi cantly reduces LPA levels in vivo.

DETAILED DESCRIPTION OF THE INVENTION

The present invention provides novel pyridazines that are surprisingly potent inhibitors of autotaxin (Assay A), further characterized by

-high potency in human whole blood (Assay B), and

-significant reduction in the plasma concentration levels of LPA in vivo over sev eral hours (Assay C).

Compounds of the present invention are useful as agents for the treatment or prevention of diseases or conditions in which ATX activity and/or LPA signalling participates, is in volved in the etiology or pathology of the disease, or is otherwise associated with at least one symptom of the disease. ATX-LPA signalling has been implicated for example in an giogenesis, chronic inflammation, autoimmune diseases, fibrotic diseases, cancer progres sion and tumor metastasis.

Compounds of the invention are superior to those disclosed in the prior art in terms of the combination of the following parameters:

-potency as inhibitors of ATX,

-potency as inhibitors of ATX in human whole blood,

-reducing the plasma concentration levels of LPA in vivo over several hours

ATX is a soluble plasma protein, which is active in heparinized whole blood. Its substrate LPC is highly abundant, its concentration being in the mM range. Therefore, a whole blood assay at physiological substrate concentrations is a highly relevant assay, predictive for the efficacy of ATX inhibitors in vivo.

LPA reduction in vivo is determined by measuring the plasma concentration of LPA after oral dosage of the compounds of the present invention. LPA is a very strong bioactive li pid, which efficiently activates downstream pathways via the LPA-receptors 1-6 in a con centration dependent manner. The pronounced and sustained blockage of the LPA for mation via ATX inhibition is assessed by measuring the extent of LPA reduction 8 hours after compound dosage. A high reduction of plasma LPA at 8 h is therefore highly indica tive for efficacy and sustained duration of action in vivo as well as sustained target engage ment of the LPA receptors.

Compounds of the present invention differ structurally from examples 2 and 12 in

WO2014/139882 and example 19 in ACS Med. Chem. Lett. 2017, 8, 1252-1257, in that they contain a central pyridazine core with substituents in the 3- and 6- positions. This structural difference unexpectedly leads to a superior combination of (i) inhibition of ATX, (ii) inhibition of ATX in human whole blood, and (iii) reduced plasma concentration levels of LPA in vivo over several hours.

Consequently, compounds of the present invention demonstrate high in vivo target engage ment and can be expected to have higher efficacy in humans. The present invention provides novel compounds according to formula (I)

wherein

A is pyridyl substituted with one or two members of the group consisting of fluoro and Fi- 7-fluoro-Ci- ₃ -alkyl;

E is selected from the group consisting of phenyl and pyridyl optionally substituted with one or two members of the group consisting of fluoro and Fi- ₇ -fluoro-Ci- ₃ -alkyl; K is selected from the group consisting of

R ³ is selected from the group consisting of R ⁴ (0)C-, methyl, and

R ⁴ is methyl. Another embodiment of the present invention relates to a compound of formula (I), wherein A is pyridyl substituted with one or two of F _1-3 -fluoro-Ci -alkyl; and substituents E and K are defined as in the preceding embodiment.

Another embodiment of the present invention relates to a compound of formula (I), wherein A is pyridyl substituted with one or two members of the group consisting of F ₂ HC, and F ₃ C; and substituents E and K are defined as in the preceding embodiment.

Another embodiment of the present invention relates to a compound of formula (I), wherein A is selected from the group consisting of

and substituents E and K are defined as in any of the preceding embodiments.

Another embodiment of the present invention relates to a compound of formula (I),

wherein E is selected from the group consisting of phenyl and pyridyl optionally substituted with one or two members of the group consisting of F and F ₃ C;

and substituents A and K are defined as in any of the preceding embodiments.

Another embodiment of the present invention relates to a compound of formula (I), wherein E is selected from the group consisting of

and substituents A and K are defined as in any of the preceding embodiments.

Preferred is a compound of formula (I), according to the present invention, selected from the group consisting of

A further embodiment relates to a pharmaceutical composition comprising at least one compound of formula I according to the present invention or a pharmaceutically acceptable salt thereof and one or more pharmaceutically acceptable excipients.

A further embodiment relates to a compound of formula (I) according to the present inven tion, for use as a medicament. USED TERMS AND DEFINITIONS

Terms not specifically defined herein should be given the meanings that would be given to them by one of skill in the art in light of the disclosure and the context. As used in the specification, however, unless specified to the contrary, the following terms have the meaning indicated and the following conventions are adhered to.

In the groups, radicals, or moieties defined below, the number of carbon atoms is often specified preceding the group, for example, Ci- ₆ -alkyl means an alkyl group or radical hav ing 1 to 6 carbon atoms. In general in groups like HO, ¾N, (O)S, (0) ₂ S, NC (cyano), HOOC, F ₃ C or the like, the skilled artisan can see the radical attachment point(s) to the molecule from the free valences of the group itself. For combined groups comprising two or more subgroups, the last named subgroup is the radical attachment point, for example, the substituent "aryl-Ci- ₃ -alkyl" means an aryl group which is bound to a C _1-3 -alkyl-group, the latter of which is bound to the core or to the group to which the substituent is attached. In case a compound of the present invention is depicted in form of a chemical name and as a formula in case of any discrepancy the formula shall prevail. An asterisk is may be used in sub-formulas to indicate the bond which is connected to the core molecule as defined. The numeration of the atoms of a substituent starts with the atom which is closest to the core or to the group to which the substituent is attached.

For example, the term "3-carboxypropyl-group" represents the following substituent:

wherein the carboxy group is attached to the third carbon atom of the propyl group. The terms " 1-methylpropyl-", "2,2-dimethylpropyl-" or "cyclopropylmethyl-" group represent the following groups:

The asterisk may be used in sub-formulas to indicate the bond which is connected to the core molecule as defined.

The term "substituted" as used herein, means that any one or more hydrogens on the desig nated atom is replaced with a selection from the indicated group, provided that the desig- nated atom's normal valence is not exceeded, and that the substitution results in a stable compound.

The term "Ci- _n -alkyl", wherein n is an integer selected from 2, 3, 4, 5 or 6, preferably 4 or 6, either alone or in combination with another radical denotes an acyclic, saturated, branched or linear hydrocarbon radical with 1 to n C atoms. For example the term Ci-s-al- kyl embraces the radicals ¾C-, H3C-CH2-, H3C-CH2-CH2-, H C-CH(CH3)-,

H3C-CH2-CH2-CH2-, H C-CH2-CH(CH3)-, H C-CH(CH3)-CH2-, H C-C(CH3)2-,

H3C-CH2-CH2-CH2-CH2-, H3C-CH ₂ -CH ₂ -CH(CH3)-, H3C-CH ₂ -CH(CH3)-CH ₂ -,

H ₃ C-CH(CH3)-CH2-CH ₂ -, H ₃ C-CH ₂ -C(CH3)2-, H ₃ C-C(CH3)2-CH ₂ -,

H C-CH(CH3)-CH(CH3)- and H3C-CH ₂ -CH(CH ₂ CH3)-.

The term "halogen" denotes chlorine, bromine, iodine, and fluorine. By the term "halo" added to an "alkyl", "alkylene" or "cycloalkyl" group (saturated or unsaturated) is such a alkyl or cycloalkyl group wherein one or more hydrogen atoms are replaced by a halogen atom selected from among fluorine, chlorine or bromine, preferably fluorine and chlorine, particularly preferred is fluorine. Examples include: H2FC-, HF2C-, F3C-.

The term phenyl refers to the radical of the following ring

The term pyridinyl refers to the radical of the following ring

The term pyridazine refers to the following ring

Unless specifically indicated, throughout the specification and the appended claims, a given chemical formula or name shall encompass tautomers and all stereo, optical and geo metrical isomers (e.g. enantiomers, diastereomers, E/Z isomers, etc.) and racemates thereof as well as mixtures in different proportions of the separate enantiomers, mixtures of dia stereomers, or mixtures of any of the foregoing forms where such isomers and enantiomers exist, as well as salts, including pharmaceutically acceptable salts thereof and solvates thereof such as for instance hydrates including solvates of the free compounds or solvates of a salt of the compound.

In general, substantially pure stereoisomers can be obtained according to synthetic princi ples known to a person skilled in the field, e.g. by separation of corresponding mixtures, by using stereochemically pure starting materials and/or by stereoselective synthesis. It is known in the art how to prepare optically active forms, such as by resolution of racemic forms or by synthesis, e.g. starting from optically active starting materials and/or by using chiral reagents.

Enantiomerically pure compounds of the present invention or intermediates may be pre pared via asymmetric synthesis, for example by preparation and subsequent separation of appropriate diastereomeric compounds or intermediates which can be separated by known methods (e.g. by chromatographic separation or crystallization) and/or by using chiral rea gents, such as chiral starting materials, chiral catalysts or chiral auxiliaries.

Further, it is known to the person skilled in the art how to prepare enantiomerically pure compounds from the corresponding racemic mixtures, such as by chromatographic separa- tion of the corresponding racemic mixtures on chiral stationary phases; or by resolution of a racemic mixture using an appropriate resolving agent, e.g. by means of diastereomeric salt formation of the racemic compound with optically active acids or bases, subsequent resolution of the salts and release of the desired compound from the salt; or by derivatiza- tion of the corresponding racemic compounds with optically active chiral auxiliary rea gents, subsequent diastereomer separation and removal of the chiral auxiliary group; or by kinetic resolution of a racemate (e.g. by enzymatic resolution); by enantio selective crystal lization from a conglomerate of enantiomorphous crystals under suitable conditions; or by (fractional) crystallization from a suitable solvent in the presence of an optically active chi ral auxiliary.

The phrase "pharmaceutically acceptable" is employed herein to refer to those compounds, materials, compositions, and/or dosage forms which are, within the scope of sound medical judgment, suitable for use without excessive toxicity, irritation, allergic response, or other problem or complication, and commensurate with a reasonable benefit/risk ratio.

As used herein, "pharmaceutically acceptable salt" refers to derivatives of the disclosed compounds wherein the parent compound forms a salt or a complex with an acid or a base. Examples of acids forming a pharmaceutically acceptable salt with a parent compound containing a basic moiety include mineral or organic acids such as benzenesulfonic acid, benzoic acid, citric acid, ethanesulfonic acid, fumaric acid, gentisic acid, hydrobromic acid, hydrochloric acid, maleic acid, malic acid, malonic acid, mandelic acid, methanesul- fonic acid, 4-methyl-benzenesulfonic acid, phosphoric acid, salicylic acid, succinic acid, sulfuric acid and tartaric acid.

Examples for cations and bases forming a pharmaceutically acceptable salt with a parent compound containing an acidic moiety include Na ⁺ , K ⁺ , Ca ²⁺ , Mg ²⁺ , NH ₄ ⁺ , L-arginine, 2,2’-iminobisethanol, L-lysine, /V-methyl-D-glucamine or tris(hydroxymethyl)-amino- methane.

The pharmaceutically acceptable salts of the present invention can be synthesized from the parent compound which contains a basic or acidic moiety by conventional chemical meth- ods. Generally, such salts can be prepared by reacting the free acid or base forms of these compounds with a sufficient amount of the appropriate base or acid in water or in an or ganic diluent like ether, ethyl acetate, ethanol, isopropanol, or acetonitrile, or a mixture thereof.

Salts of other acids than those mentioned above which for example are useful for purifying or isolating the compounds of the present invention (e.g. trifluoroacetate salts,) also com prise a part of the present invention.

BIOLOGICAL ASSAYS The biological activity of compounds was determined by the following methods:

Assay A: Biochemical ATX assay

5 nM recombinant ATX (Cayman Chemicals) was supplemented to 50 mM Tris buffer (pH 8.0) containing 3 mM KC1, 1 mM CaC12, 1 mM MgC12 0.14 mM NaCl, and 0.1% bovine serum albumin. Test compounds were dissolved in DMSO and tested in the range of 0.1 nM to 10 mM. The enzymatic reaction (22.5 pL) was started by addition of 2.5 pL 10 pM 18: 1 LPC (Avanti Lipids, Alabaster, AL, USA). After 2-h incubation at room temperature, the reaction was stopped by addition of 20 pL water containing 500 nM 20:4 LPA as inter nal standard and 100 pL 1 -butanol for extracting LPA. Subsequently, the plates were cen trifuged at 4000 rpm, 4 °C, for 2 min. The resultant upper butanol phase was directly used for injection at a RapidFire system (Agilent).

The RapidFire autosampler was coupled to a binary pump (Agilent 1290) and a Triple Quad 6500 (ABSciex, Toronto, Canada). This system was equipped with a 10-pL loop, 5- pL Waters Atlantis HILIC cartridge (Waters, Elstree, UK), 90% acetonitrile containing 10 mM ammonium acetate as eluent A and 40% acetonitrile containing 10 mM ammoni- umacetate as eluent B. For details see (Bretschneider et al. , SLAS Discovery, 2017). 1 The MS was operated in negative mode with a source temperature of 550 °C, curtain gas = 35, gas 1 = 65, and gas 2 = 80. The following transitions and MS parameters (DP: declustering potential and CE: collision energy) for the respective LPAs were determined:

18: 1 LPA at 435.2/152.8, DP = -40, CE = -28 and 20:4 LPA at 457.2/152.8, DP = -100, CE = -27).

The formation of 18: 1 LPA was monitored and evaluated as ratio to 20:4 LPA.

Table 1 : Biological data for compounds for the invention as obtained in Assay A

Table 2: Biological data for prior art compounds (examples 2 and 12 in WO2014/139882) as obtained in Assay A.

Table 3: Biological data for prior art compounds (example 19 in ACS Med. Chem. Lett. 2017, 8, 1252-1257) as obtained in Assay A.

Assay B: Whole-blood ATX assay

45 pL human whole-blood was supplemented with 5 pL of the test compound, dissolved in phosphate-buffered saline (concentration range 0.12 nM - 100 pM). This mixture was in cubated for 1 h at 37 °C and stopped by addition of 100 pL 40 mM disodium hydrogen phosphate buffer containing 30 mM citric acid (pH 4) and 1 pM 17:0 LPA (internal stand- ard). LPA was extracted by addition of 500 pL 1 -butanol, followed by 10-min centrifuga tion at 4000 rpm, 4 °C. From the resultant organic supernatant, a 200 pL aliquot was trans ferred into a 96-deep-well plate and transferred to the RapidFire-based MS/MS measure ment.

The RapidFire autosampler was coupled to a binary pump (Agilent 1290) and a Triple Quad 6500 (ABSciex, Toronto, Canada). This system was equipped with a 10-pL loop, 5- pL Waters Atlantis HILIC cartridge (Waters, Elstree, UK), 90% acetonitrile containing 10 mM ammonium acetate as eluent A and 40% acetonitrile containing 10 mM ammoni- umacetate as eluent B. For details see (Bretschneider et al ., SLAS Discovery, 2017, 22, 425-432). The MS was operated in negative mode with a source temperature of 550 °C, curtain gas = 35, gas 1 = 65, and gas 2 = 80. The following transitions and MS parameters (DP: declustering potential and CE: collision energy) for the respective LPAs were deter mined: 18:2 LPA at 433.2/152.8, DP = -150, CE = -27 and 17:0 LPA at 423.5/152.8, DP = 100

The formation of 18:2 LPA was monitored and evaluated as ratio to 17:0 LPA.

Table 4: Biological data for compounds for the invention as obtained in Assay B.

Table 5: Biological data for prior art compounds (examples 2 and 12 in WO2014/139882) as obtained in Assay B.

Table 6: Biological data for prior art compounds (example 19 in ACS Med. Chem. Lett. 2017, 8, 1252-1257) as obtained in Assay B.

Assay C: in vivo

The test substance was solubilized in 0.5% natrosol supplemented with 0.015% Tween 80 for oral application to rats at a dose of 5 mg/kg. Blood samples were collected before com pound administration and 8 hours post application on ice using EDTA as coagulation agent. Subsequently, plasma was prepared by centrifugation and stored until analysis at -20 °C.

LPAs from plasma samples were extracted by using the procedure described by Scherer et al. ( Clinical chemistry 2009, 55, 1218-22). 35 pL of heparinized plasma was mixed with 200 pL 40 mM disodium hydrogen phosphate buffer containing 30 mM citric acid (pH 4) and 1 pM 17:0 LPA (internal standard). Subsequently, 500 pL butanol was added and shaken vigorously for 10 min. Samples were centrifuged afterwards at 4000 rpm, 4 °C, for 10 min. 500 pL of the organic upper phase was transferred to a fresh 96-deep-well plate and evaporated with a gentle nitrogen flow of 15 psi for 45 min. The resultant residual was dissolved in 100 pL ethanol prior to LC-MS analysis.

LC-MS method for the analytic of in vivo samples

A Triple Quad 6500 (ABSciex, Toronto, Canada) was equipped with an Agilent 1290 LC system (Agilent, Santa Clara, CA) a CTC autosampler and an Atlantis 50 x 2.1-mm, 3-pm HILIC LC column (Waters, Elstree, UK). Eluent A contained 0.2% formic acid and 50 mM ammonium formate in water, whereas eluent B consisted of 0.2% formic acid in ace tonitrile. The LC gradient started from 95% solvent B and decreased within 1.5 min to 75% and within 0.2 min to 50% solvent B, with a further increase in the flow rate from 500 to 700 pL · min ^-1 . At 1.8 min, solvent B was set back to 95% and stayed constant for 0.7 min for re-equilibration of the column. The following LPA species were monitored (DP: declustering potential and CE: collision energy): 16:0 LPA at 409.2/152.8, DP = -150, CE = -28; 18:0 LPA at 437.3/152.8, DP = -60, CE = -28; 18: 1 LPA at 435.2/152.8, DP = -40, CE = -28; 18:2 LPA at 433.2/152.8, DP = -150, CE = -28; 20:4 LPA at 457.2/152.8, DP = -100, CE = -29 and 17:0 LPA at 423.5/152.8, DP = -100, CE = -36. LPA depletion in percent was calculated based on the baseline LPA levels before test com pound application. The sum of LPA refers to the species 16:0; 18:0; 18: 1; 18:2 and 20:4 Table 7: Biological data for compounds for the invention as obtained in Assay C.

Table 8: Biological data for prior art compounds (examples 2 and 12 in WO2014/139882) as obtained in Assay C.

Table 9: Biological data for prior art compound (example 19 in ACS Med. Chem. Lett. 2017, 8, 1252-1257) as obtained in Assay C.

METHOD OF TREATMENT

The present invention is directed to compounds of general formula (I) which are useful in the prevention and/or treatment of a disease and/or condition associated with or modulated by ATX and/or the biological activity of LPA, including but not limited to the treatment and/or prevention of inflammatory conditions, fibrotic diseases, conditions of the respira tory system, renal conditions, liver conditions, vascular and cardiovascular conditions, can cer, ocular conditions, metabolic conditions, cholestatic and other forms of chronic pruritus and acute and chronic organ transplant rejection and conditions of the nervous system.

The compounds of general formula (I) are useful for the prevention and/or treatment of in flammatory conditions including, but not limited to Sjogren’s syndrome, arthritis, osteoar thritis, multiple sclerosis, systemic lupus erythematousus, inflammatory bowel disease, in flammatory airways diseases such as chronic obstructive pulmonary disease (COPD) and chronic asthma; fibrotic diseases including, but not limited to interstitial lung diseases (ILDs) including Progressive Fibrosing Interstitial Lung Diseases (PFILDs) such as idio pathic pulmonary fibrosis (IPF), and SSC-ILD, familial interstitial lung disease myocardial and vascular fibrosis, renal fibrosis, liver fibrosis, pulmonary fibrosis, skin fibrosis, colla gen vascular disease including Systemic Sclerosis (SSc) and encapsulating peritonitis; con ditions of the respiratory system including, but not limited to diffuse parenchymal lung dis eases of different etiologies including iatrogenic drug-induced fibrosis, occupational and/or environmental induced fibrosis, systemic diseases and vasculitides, granulomatous diseases (sarcoidosis, hypersensitivity pneumonia), renal conditions including, but not limited to acute kidney injury and chronic renal disease with and without proteinuria including End- Stage Renal Disease (ESRD, focal segmental glomerular sclerosis, IgA nephropathy, vas culitides / systemic diseases as well as acute and chronic kidney transplant rejection; liver conditions including, but not limited to liver cirrhosis, hepatic congestion, cholestatic liver disease including pruritus, primary biliary cholangitis, non-alcoholic steatohepatitis and acute and chronic liver transplant rejection; vascular conditions including, but not limited to atherosclerosis, thrombotic vascular disease as well as thrombotic microangiopathies, proliferative arteriopathy (such as swollen myointimal cells surrounded by mucinous extra cellular matrix and nodular thickening), endothelial dysfunction; cardiovascular conditions including, but not limited to acute coronary syndrome, coronary heart disease, myocardial infarction, arterial and pulmonary hypertension, cardiac arrhythmia such as atrial fibrilla tion, stroke and other vascular damage; cancer and cancer metastasis including, but not limited to breast cancer, ovarian cancer, lung cancer, prostate cancer, mesothelioma, gli oma, hepatic carcinoma, gastrointestinal cancers and progression and metastatic aggres siveness thereof; ocular conditions including, but not limited to proliferative and non-pro- liferative (diabetic) retinopathy, dry and wet age-related macular degeneration (AMD), macular oedema, central arterial /venous occlusion, traumatic injury, glaucoma; metabolic conditions including, but not limited to obesity, dyslipidaemia and diabetes; conditions of the nervous system including, but not limited to neuropathic pain, Alzheimer’s disease, schizophrenia, neuro-inflammation (for example, astrogliosis), peripheral and/or autonomic (diabetic) neuropathies.

Accordingly, the present invention relates to a compound of general formula (I) for use as a medicament.

Furthermore, the present invention relates to the use of a compound of general formula (I) for the treatment and/or prevention of a disease and/or condition associated with or modu lated by ATX and/or the biological activity of LPA.

Furthermore, the present invention relates to the use of a compound of general formula (I) for the treatment and/or prevention of a disease and/or condition associated with or modu lated by ATX and/or the biological activity of LPA, including but not limited to inflamma tory conditions, fibrotic diseases, conditions of the respiratory system, renal conditions, liver conditions, vascular and cardiovascular conditions, cancer, ocular conditions, meta bolic conditions, cholestatic and other forms of chronic pruritus and acute and chronic or gan transplant rejection and conditions of the nervous system.

Furthermore, the present invention relates to the use of a compound of general formula (I) for the treatment and/or prevention of inflammatory conditions including, but not limited to Sjogren’s syndrome, arthritis, osteoarthritis, multiple sclerosis, systemic lupus erythem- atousus, inflammatory bowel disease, inflammatory airways diseases such as chronic ob structive pulmonary disease (COPD) and chronic asthma; fibrotic diseases including, but not limited to interstitial lung diseases (ILDs) including Progressive Fibrosing Interstitial Lung Diseases (PFILDs) such as idiopathic pulmonary fibrosis (IPF), and SSC-ILD, famil ial interstitial lung disease myocardial and vascular fibrosis, renal fibrosis, liver fibrosis, pulmonary fibrosis, skin fibrosis, collagen vascular disease including Systemic Sclerosis (SSc) and encapsulating peritonitis; conditions of the respiratory system including, but not limited to diffuse parenchymal lung diseases of different etiologies including iatrogenic drug-induced fibrosis, occupational and/or environmental induced fibrosis, systemic dis eases and vasculitides, granulomatous diseases (sarcoidosis, hypersensitivity pneumonia), renal conditions including, but not limited to acute kidney injury and chronic renal disease with and without proteinuria including end-stage renal disease (ESRD, focal segmental glomerular sclerosis, IgA nephropathy, vasculitides / systemic diseases as well as acute and chronic kidney transplant rejection; liver conditions including, but not limited to liver cir rhosis, hepatic congestion, cholestatic liver disease including pruritus, primary biliary chol angitis, non-alcoholic steatohepatitis and acute and chronic liver transplant rejection; vas cular conditions including, but not limited to atherosclerosis, thrombotic vascular disease as well as thrombotic microangiopathies, proliferative arteriopathy (such as swollen myo- intimal cells surrounded by mucinous extracellular matrix and nodular thickening), endo thelial dysfunction; cardiovascular conditions including, but not limited to acute coronary syndrome, coronary heart disease, myocardial infarction, arterial and pulmonary hyperten sion, cardiac arrhythmia such as atrial fibrillation, stroke and other vascular damage; can cer and cancer metastasis including, but not limited to breast cancer, ovarian cancer, lung cancer, prostate cancer, mesothelioma, glioma, hepatic carcinoma, gastrointestinal cancers and progression and metastatic aggressiveness thereof; ocular conditions including, but not limited to proliferative and non-proliferative (diabetic) retinopathy, dry and wet age-related macular degeneration (AMD), macular oedema, central arterial /venous occlusion, trau matic injury, glaucoma; metabolic conditions including, but not limited to obesity, dyslipi- daemia and diabetes; conditions of the nervous system including, but not limited to neuro pathic pain, Alzheimer’s disease, schizophrenia, neuro-inflammation (for example, astro- gliosis), peripheral and/or autonomic (diabetic) neuropathies.

In a further aspect the present invention relates to a compound of general formula (I) for use in the treatment and/or prevention of above mentioned diseases and conditions. In a further aspect the present invention relates to the use of a compound of general for mula (I) for the preparation of a medicament for the treatment and/or prevention of above mentioned diseases and conditions.

In a further aspect of the present invention the present invention relates to methods for the treatment or prevention of above mentioned diseases and conditions, which method com prises the administration of an effective amount of a compound of general formula (I) to a human being.

PHARMACEUTICAL COMPOSITIONS

Suitable preparations for administering the compounds of formula (I) will be apparent to those with ordinary skill in the art and include for example tablets, pills, capsules, supposi tories, lozenges, troches, solutions, syrups, elixirs, sachets, injectables, inhalatives and powders etc..

Suitable tablets may be obtained, for example, by mixing one or more compounds accord ing to formula I with known excipients, for example inert diluents, carriers, disintegrants, adjuvants, surfactants, binders and/or lubricants.

COMBINATION THERAPY

Compounds according to the present invention can be combined with other treatment op tions known to be used in the art so that at least two active compounds in effective amounts are used to treat an indication for which the present invention is useful at the same time. Although combination therapy preferably includes the administration of two active compounds to the patient at the same time, it is not necessary that the compounds be ad ministered to the patient at the same time, although effective amounts of the individual compounds will be present in the patient at the same time. Compounds according to the present invention may be administered with one or more combination partners as otherwise described herein. Accordingly, the present invention provides a compound of formula (I) according to any of the preceding embodiments, characterised in that the compound of formula (I) is adminis tered in addition to treatment with one or more anti-inflammatory molecules from the list consisting of IL6 modulators, anti-IL6R modulators and IL13/IL-4 JAKi modulators. According to another aspect, the present invention provides a compound of formula (I) ac cording to any of the preceding embodiments, characterised in that the compound of for mula (I) is administered in addition to treatment with one or more anti-fibrotic molecules from the list consisting of CB2 agonists, TGF modulators, FGFR modulators, VEGFR in hibitors, PDGFR inhibitors, FGF modulators, anb6 integrin modulators, anti-CTGF anti- bodies, ROCK2 inhibitors, rhPTX-2 (Pentraxin-2), JNK1 inhibitors, LOXL2 inhibitors, Galectin3 inhibitors, MK2 inhibitors, Wnt pathway inhibitors, TGFR inhibitors, PDE4 modulators, TRPAl inhibitors and microRNA modulators.

According to another aspect, the present invention provides a compound of formula (I) ac cording to any of the preceding embodiments, characterised in that the compound of for- mula (I) is administered in addition to nintedanib.

According to another aspect, the present invention provides a compound of formula (I) ac cording to any of the preceding embodiments, characterised in that the compound of for mula (I) is administered in addition to pirfenidone. PREPARATION

The compounds according to the present invention may be obtained using methods of syn thesis which are known to the one skilled in the art and described in the literature of or ganic synthesis. Preferably the compounds are obtained analogously to the methods of preparation explained more fully hereinafter, in particular as described in the experimental section.

The general processes for preparing the compounds according to the invention will become apparent to the one skilled in the art studying the following schemes. Starting materials may be prepared by methods that are described in the literature or herein, or may be pre- pared in an analogous or similar manner. Any functional groups in the starting materials or intermediates may be protected using conventional protecting groups. These protecting groups may be cleaved again at a suitable stage within the reaction sequence using meth ods familiar to the one skilled in the art. Compounds of general formula (I) may be prepared by amide coupling of an amine (VII) with acid (VI).

Acids (VII) are obtained by saponification of esters (VI) (where R is a suitable acid pro tecting group such as methyl or ethyl). Esters (VI) are prepared by coupling benzyl alco hols (V) to halides (IV) using a base in which X is a halogen such as Cl, Br or I. Esters (IV) can be synthesized by alkylation of halopyridazines (II) with alkylhalides (III), in which Y is a halogen such as Cl, Br or iodine.

EXAMPLES

Experimental Part

The Examples that follow are intended to illustrate the present invention without restricting it. The terms "ambient temperature" and "room temperature" are used interchangeably and designate a temperature of about 20°C.

Abreviations:

Preparation of Starting Compounds

Example I

Example 1.1

4-(4- Acetylpiperazin- 1 -vO-3 -fluorobenzonitrile

To a solution of 0.40 g (1.95 mmol) 3-fluoro-4-piperazin-l-yl-benzonitrile (CAS-No. 182181-38-0) and 0.60 ml (4.30 mmol) triethylamine in 7 mL DCM is added 0.14 mL (1.95 mmol) acetyl chloride and the mixture is stirred at RT overnight. The reaction mix ture is treated with 0.09 mL (1.25 mmol) triethylamine and stirred at RT for 2 h. The or ganic layer is washed with water, dried with PTK and the solvent is evaporated under re duced pressure to afford 500 mg of the crude product.

C13H14FN3O (M = 247.3 g/mol)

ESI-MS: 248 [M+H] ⁺

R _t (HPLC): 0.82 min (method B)

The following compounds are prepared according to the general procedure (example 1.1) described above:

Example II Example II.1

1 - ! 4-r4-(aminomethyl )-2-fluorophenyllpiperazin- 1 -yljethan- 1 -one

A mixture of 550 mg (2.22 mmol) 4-(4-acetylpiperazin-l-yl)-3-fluorobenzonitrile (exa- mple 1.1), 55.0 mg Raney-Nickel and 15 mL 7 N ammonia in MeOH is stirred under a hyd rogen atmosphere (50 psi) at 50 °C overnight, filtered and reduced in vacuo to give 510 mg of the product.

C ₁₃ H ₁₈ FN ₃ O (M = 251.3 g/mol)

ESI-MS: 252 [M+H] ⁺

R _t (HPLC): 0.68 min (method A)

The following compounds are prepared according to the general procedure (example II I) described above:

Example III

Example III.1

4-(4- Acetylpiperazin- 1 -vD-2-fluorobenzonitrile

A mixture of 0.50 g (2.50 mmol) 4-bromo-2-fluorobenzonitrile (CAS-No. 105942-08-3), 0.32 g (2.50 mmol) l-(piperazin-l-yl)ethan-l-one (CAS No. 13889-98-0), 1.63 g

(5.00 mmol) cesium carbonate and 0.05 g (0.06 mmol) XPhos Pd G3 (CAS-No. 1445085- 55-1) in 2 mL 1,4-dioxane is stirred at 80 °C overnight. It is diluted with water. The re- maining solid is filtered, washed with water und dried under air atmosphere to afford 570 mg of the product.

C ₁₃ H ₁₄ FN ₃ O (M = 247.3 g/mol)

ESI-MS: 248 [M+H] ⁺

R _t (HPLC): 0.79 min (method A)

The following compound is prepared according to the general procedure (example III.1) described above:

Example IV

Example IV.1

4-(6-Methyl-7-oxo-2.6-diazaspiror3.41octan-2-

222 mg (1.81 mmol) 4-Fluorobenzonitrile (CAS No. 1194-02-1) and 320 mg (1.81 mmol) 6-methyl-2,6-diazaspiro[3.4]octan-7-one hydrochloride (CAS No.2097951-61-4) diluted with 1.6 mL DMSO are treated with 790 mg (5.62 mmol) K2CO3 and stirred at 120 °C for 3 h and at RT overnight. The reaction mixture is cooled and diluted with water. The precip itate is filtered, washed with water and dried in vacuo at 50 °C to yield 340 mg of the prod uct.

C14H15N3O (M = 241.3 g/mol)

ESI-MS: 242 [M+H] ⁺

R _t (HPLC): 0.79 min (method B)

The following compounds are prepared according to the general procedure (example IV.1) described above:

Example V

Example V.1

4- trifluoroacetic acid

255 mg (0.780 mmol) tert- Butyl 2-(4-cyanophenyl)-2,7-diazaspiro[3.5]nonane-7-carbox- ylate (example IV.2) is diluted with 5 mL DCM and 300 pL (3.89 mmol) TFA is added. The reaction mixture is stirred at RT for 2 h and concentrated under reduced pressure to af- ford 260 mg of the product. Cl ₄ Hl7N3*C2HF ₃ 02 (M = 341.3 g/mol)

ESI-MS: 228 [M+H] ⁺

R _t (HPLC): 0.69 min (method B) The following compounds are prepared according to the general procedure (example V. l) described above:

A solution of 0.90 g (3.01 mmol) /er/-butyl 6-(4-cyanophenyl)-2,6-diazaspiro[3.3]heptane- 2-carboxylate (example IV.3) in 8 mL ACN is treated with 1.14 g (6.01 mmol) p-tol- uenesulfonic acid monohydrate and stirred at RT for 24 h. The reaction mixture is diluted with DCM and extracted with sat. NaHCCb - solution. The combined organic layers are dried with MgSCE and concentrated under reduced pressure to provide 600 mg of the prod uct.

C12H13N3 (M = 199.3 g/mol)

ESI-MS: 200 [M+H] ⁺

R _t (HPLC): 0.62 min (method B)

Example VII

Ethyl 1 -(6-chloropyridazin-3 -vDcvclopropane- 1 -carboxylate

A solution of 13.8 g (68.8 mmol) Ethyl 2-(6-chloropyridazin-3-yl)acetate (CAS No.

1023817-10-8) in 100 mL DMSO is cooled with an ice-bath and treated with 8.25 g (206.4mmol) sodium hydride (60 % dispersion) . The reaction mixture is stirred for 20 min. 8.89 mL (103.2 mmol) Dibromoethane is added to the reaction mixture and is stirred under temperature control (maximum 38 °C) for 45 min. The reaction mixture is ice-cooled and diluted with EECl-solution. The aq. phase is extracted with EtOAc. The combined organic layers are dried with MgSCE and concentrated under reduced pressure. The residue is purified by column chromatography (silica gel; eluent: Cy/EtOAc = 90/10 to 65/35) to afford 11.4 g of the product.

C10H11CIN2O2 (M = 226.7 g/mol)

ESI-MS: 227 [M+H] ⁺

Rt (HPLC): 0.86 min (method B)

Example VIII

Example VIII.1

1 -(6- { r6-(DifluoromethvDpyri din-3 -vHmethoxylpyridazin-3 -vDcvclopropane- 1 -carboxylic acid

843 mg (5.29 mmol) [6-(Difluoromethyl)pyridin-3-yl]methanol (CAS No. 946578-33-2) in 8 mL DMF is cooled with an ice-bath and 385 mg (8.82 mmol) sodium hydride (55 % pu rity) is added. The mixture is stirred at RT for 10 min. 1.00 g (4.41 mmol) Ethyl l-(6/ chloropyridazin-3-yl)cyclopropane-l-carboxylate (example VII) in 5 mL DMF is added to the reaction mixture and is stirred at RT for 1 h. The reaction mixture is diluted with a cooled NEECl/solution and it is extracted with EtOAc three times. The organic phase is dried with MgSCE and concentrated in vacuo to give the ethyl ester intermediate.

The residue is treated with MeOH and 200 mg (8.35 mmol) lithium hydroxide and 3 mL water are added. The reaction mixture is stirred at RT overnight and treated with 2 mL (8.00 mmol) 4 N sodium hydroxide solution. It is stirred at 45 °C for 1 h and meanwhile THF is evaporated under reduced pressure. DIPE is added slowly to the reaction mixture and separated. The water phase is diluted with NFECl-solution, acidified by citric acid ad dition and extracted with EtOAc. The organic phase is dried with MgS04, filtered through silica gel and reduced to dryness in vacuo. The residue is purified by column chromatog- raphy (silica gel; eluent: DCM/MeOH = 100/0 to 85/15) to afford 845 mg of the product. C15H13F2N3O3 (M = 321.3 g/mol)

ESI-MS: 322 [M+H] ⁺

Rt (HPLC): 0.81 min (method B) The following compound is prepared according to the general procedure (example VIII.1) described above:

Example IX

6-(4-Acetylpiperazin- 1 -vDpyridine-3-carbonitrile

A mixture of 250 mg (2.05 mmol) 6-fluoropyridine-3-carbonitrile, 315 mg (2.46 mmol) 1- acetylpiperazine and 705 pL (4.10 mmol) DIPEA in 3 mL DMSO is stirred at 80 °C for 45 min and quenched with semi cone. NaCl/solution. The water phase is extracted with EtOAc. The combined organic phases are dried via PTK and concentrated in vacuo to af ford 420 mg of the product

C12H14N4O (M = 230.3 g/mol)

ESI-MS: 231 [M+H] ⁺

R _t (HPLC): 0.72 min (method A) Example X

Example X.1

4-(4-Acetyl-3.3-dimethylpiperazin- l -vDbenzonitrile

800 mg (1.21 mmol) 4-(3,3-Dimethylpiperazin-l-yl)benzonitrile trifluoroacetic acid (ex ample V.6) is dissolved in 3 mL pyridine and 2.00 mL (21.2 mmol) acetic anhydride is added. The reaction mixture is refluxed overnight and evaporated under reduced pressure. The residue is taken up in sat. NaHCCb-solution and extracted with EtOAc. The organic layer is dried, concentrated in vacuo and purified by column chromatography (silica gel; eluent: DCM/MeOH = 98/2 to 9/1) to afford 80 mg of the product.

C ₁₅ H ₁₉ N ₃ O (M = 257.3 g/mol)

ESI-MS: 258 [M+H] ⁺

R _t (HPLC): 0.85 min (method A) The following compound is prepared according to the general procedure (example X.1) de scribed above:

A solution of 56.5 mg (0.47 mmol) 4-fluorobenzonitrile (CAS No. 1194-02-1) and 100 mg (0.47mmol) tert-butyl 3,3-dimethylpiperazine-l-carboxylate (CAS No. 259808-67-8) in 3 mL NMP is treated with 120 pL (0.71mmol) DIPEA and stirred at 190 °C for 7 h under microwave irridation. The reaction mixture is diluted with water and EtOAc , the organic layer is separated and washed with sat. NaHCCb-solution. The organic layer is dried, fil tered and concentrated under reduced pressure to afford 120 mg of the product.

C13H17N3 (M = 215.29 g/mol)

ESI-MS: 216 [M+H] ⁺

R _t (HPLC): 0.84 min (method A) Preparation of Final Compounds

Example 1.1

N-(4-(7-acetyl-2.7-diazaspiror3.51nonan-2-yl )benzyl )- l -(6-((6-(trif1uorom ethyl )pyridin-3- vOmethoxy)pyridazin-3-vOcvclopropane-l -carboxamide

300 mg (0.88 mmol) l-(6-((6-(trifluoromethyl)pyri din-3 -yl)methoxy)pyridazin-3-yl)cyclo- propane-1 -carboxylic acid (example VIII.2) and 0.45 mL (2.65 mmol) DIPEA are diluted with 3 mL DMF and 370 mg (0.97 mmol) HATU is added. The mixture is stirred at RT for 5 min, then 242 mg (0.88 mmol) l-(2-(4-(aminomethyl)phenyl)-2,7-diazaspiro[3.5]nonan- 7-yl)ethan-l-one (example II.4) is added. The reaction mixture is stirred for 30 min at RT, diluted with MeOH and purified by HPLC to yield the product.

C31H33F3N6O3 (M = 594.6 g/mol)

ESI-MS: 595 [M+H] ⁺

R _t (HPLC): 0.96 min (method A)

¾ NMR (400 MHz, DMSO-de) d 8.90 (d, =1.39 Hz, 1H), 8.20 (dd, =1.46, 8.05 Hz, 1H), 7.91-7.99 (m, 2H), 7.61 (d, =9.13 Hz, 1H), 7.27 (d, =9.13 Hz, 1H), 7.02 (d, =8.49 Hz, 2H), 6.35 (d, =8.49 Hz, 2H), 5.67 (s, 2H), 4.13 (d, =5.83 Hz, 2H), 3.54 (d, =1.77 Hz, 4H), 3.40 (td, =5.61, 14.38 Hz, 4H), 1.99 (s, 3H), 1.61-1.78 (m, 4H), 1.22-1.46 (m, 4H)

The following compounds are prepared according to the general procedure (example 1.1) described above:

Analytical HPLC methods

Method A

Analytical column: XBridge C18 (Waters) 2.5 mih; 3.0 x 30 mm; column temperature:

60 °C

Method B

Analytical column: Stable Bond (Agilent) 1.8 pm; 3.0 x 30 mm; column temperature:

60 °C

Method C

Analytical column: XBridge (Waters) C18 3.0 x 30 mm_2.5 pm; column temperature: 60 °C Method D

Analytical column: XBridge C18 3.0 x 30 mm_2.5 pm (Waters); column temperature:

60 °C

Method E

Analytical column: Sunfire (Waters) 2.5 pm; 3.0 x 30 mm; column temperature: 60 °C

Method F

Analytical column: XBridge C18 (Waters) 2.5 pm; 3.0 x 30 mm; column temperature:

60 °C Method G

Analytical column: Sunfire C18 (Waters) 2.5 mih; 3.0 x 30 mm; column temperature:

60°C

Method H

Analytical column: Sunfire C18 (Waters) 2.5 pm; 3.0 x 30 mm; column temperature:

60°C

Method I

Analytical column: Sunfire C18 (Waters) 2.5 pm; 3.0 x 30 mm; column temperature: 60 °C