MC2r modulator compounds

Abstract

The disclosures herein relate to compounds of Formula (1) and (2): (1); (2); or a pharmaceutically acceptable salt thereof and their use in treating, preventing, ameliorating, controlling or reducing the risk of disorders associated with the melanocortin subtype-2 receptor (MC2R).

Description

[0001] MC2R MODULATOR COMPOUNDS

[0002] This application relates to novel compounds and their use as melanocortin subtype-2 receptor (MC2R) antagonists. Compounds described herein may be useful in the treatment or prevention of diseases in which MC2R is involved. This application is also directed to pharmaceutical compositions comprising these compounds and the manufacture and use of these compounds and compositions in the prevention or treatment of such diseases in which MC2R is involved.

[0003] BACKGROUND OF THE INVENTION

[0004] Adenocorticotropic hormone (ACTH) is a 39-amino acid peptide implicated in the regulation of adrenal glucocorticoid synthesis and secretion within the hypothalamic-pituitary-adrenal (HPA) axis, and as such, plays a primary role in regulation of stress responses. ACTH is synthesized by corticotropic cells in the anterior pituitary via proteolytic cleavage of proopiomelanocortin (POMC). Upon stressful stimuli, ACTH is secreted and acts at the melanocortin 2 receptor (MC2R) in adrenal glands to regulate synthesis and secretion of glucocorticoids and androgens. The secretion of glucocorticoids provides negative feedback to both hypothalamus and anterior pituitary to reduce production and secretion of corticotropic releasing hormone (CRH) and ACTH respectively - thereby providing a fine balance in regulating stress responses. Diseases linked to ACTH dysfunction range from Cushing’s disease to congenital adrenal hyperplasia, ectopic ACTH syndrome (or ectopic Cushing’s syndrome) and polycystic ovarian syndrome (PCOS) (Microsc. Res. Tech. 61 , 275-287 (2003)).

[0005] The MC2R belongs to the melanocortin family of G protein-coupled receptors (GPCRs), of which there are five subtypes - MC1 R, MC2R, MC3R, MC4R and MC5R. MC1 R is associated with pigmentation regulation, MC2R with glucocorticoid synthesis, MC3R and MC4R with energy homeostasis and MC5R with exocrine gland physiology. MC2R is selectively activated by ACTH, while the remaining receptor subtypes also bind the melanocortin peptides a-, -, and y-melanocyte-stimulating hormone (a-MSH, p-MSH, and y-MSH) (Am. J. Physiol. Endocrinol. Metab. 284, E468-74 (2003); Life Sci. 59, 797-801 (1996)).

[0006] Another unique aspect of the MC2R relative to the other melanocortin receptors is that the accessory protein, MRAP (melanocortin 2 receptor protein), is required for MC2R expression and function. MRAP is a single transmembrane protein which forms an antiparallel homodimer with MC2R to allow trafficking of the receptor to the plasma membrane (Proc. Natl. Acad. Sci. 104, 20244 LP - 20249 (2007)) Binding of ACTH to the MC2R / MRAP complex in adrenal cortical cells activates cAMP production via the Gssignalling pathway. Increases in intracellular cAMP in turn stimulates cortisol synthesis and secretion (Microsc. Res. Tech. 61 , 275-287 (2003)).

[0007] Congenital adrenal hyperplasia (CAH) is a disorder characterised by disruption in adrenal steroidogenesis linked to excessive ACTH and CRH production. Three enzyme deficiencies arising from specific gene mutations are implicated: 21 -hydroxylase deficiency from mutations in CYP21A2 (the most common form), 3p-hydroxysteroid dehydrogenase (HSD3B2) and 11 p- hydroxylase (CYP11B1). In CAH, these enzyme deficiencies impair cortisol synthesis, resulting in a loss of cortisol negative feedback on CRH and ACTH. Excess ACTH results in steroidogenesis proximal to the deficient enzyme, leading to the hyperandrogenic pathophysiology associated with the disorder. CAH patients can present with hirsutism, acne, alopecia oligomenorrhea and infertility associated with virilization. Glucocorticoid and mineralocorticoid hormone replacement therapies are mainstay treatments, however require close monitoring to balance overtreatment and undertreatment. Further, ‘stress dosing’ is required at times of significant stress, illness or surgery ( . Pediatr. Adolesc. Gynecol. 30, 520-534 (2017)). Importantly, high doses of glucocorticoid replacement are required to inhibit ACTH production and thereby reduce adrenal androgen levels. This often means that in order to control adrenal androgen levels, patients will suffer from corticosteroid-associated side effects or Cushing’s-like symptoms. Thus, there remains a need for better treatments of CAH. As ACTH is elevated in CAH, inhibition of its activity, through antagonism of MC2R, provides an attractive means of modulating the steroidogenesis pathway.

[0008] Cushing’s disease is a rare disease associated with excess secretion of ACTH caused by adenomas of pituitary corticotropic cells. Clinical presentations include obesity, hirsutism, muscle weakness as well as cardiovascular and metabolic complications associated with hypercortisolism. Treatments for Cushing’s disease involve removal of either the ACTH- secreting tumour in the pituitary, or removal of the adrenal glands, however drug treatment is often used in addition to, or before surgery to alleviate symptoms. Current drug therapies aim to inhibit adrenal steroidogenesis, however, are not without adverse effects such as hypothyroidism and hypogonadism ( . Med. Life 9, 12-18 (2016)). Inhibition of ACTH activity via MC2R antagonism provides a potential therapeutic option in management of this disease.

[0009] In addition to CAH and Cushing’s disease, polycystic ovary syndrome (PCOS) may be amenable to MC2 modulation. PCOS is associated with abnormal regulation of steroidogenesis and excess androgen levels. In a subset of patients the androgen excess results from functional adrenal hyperandrogenism (Endocr. Rev. 37, 467-520 (2016)). Modulation of ACTH activity in these patients offers another therapeutic avenue for this multisystem disorder.

[0010] Thus, antagonism of MC2R presents an important therapeutic modality for treatment of diseases associated with ACTH dysfunction. WO2019 / 23669, WO2021 / 091788, WO2021 / 126693, WO2021 / 133563 and WO2024 / 175928 disclose MC2R antagonist compounds.

[0011] Long duration of action is a widely sought after feature in drug design, enabling prolonged efficacy and simplified dosing regimes (British Journal of Pharmacology 2010, 161(3), 488- 508). In the treatment of diseases associated with ACTH dysfunction, in particular diseases with excess ACTH, inhibitors with longer residence times offer the advantage of insurmountable antagonism, whereby receptor inhibition remains in the face of high ACTH concentrations. A means of achieving these favourable drug properties involves developing a compound with slow dissociation (kOff) kinetics (Neurochemistry international 2007, 51(5), 254-260). This has been demonstrated at various targets, ranging from fevipiprant at the DP2 receptor to NKi neurokinin receptor antagonists (Mol Pharmacol 2016, 89(5), 593-605; The Journal of pharmacology and experimental therapeutics 2007, 322(3), 1286-1293).

[0012] THE INVENTION

[0013] The present invention provides compounds having activity as melanocortin subtype-2 receptor (MC2R) antagonists.

[0014] Provided is a compound of Formula (1) or (2): or a pharmaceutically acceptable salt thereof. Compounds of the present invention may be used as melanocortin subtype-2 receptor (MC2R) modulators. Compounds of the present invention may be used as MC2R inhibitors. Compounds of the present invention may be used as MC2R antagonists. Compounds of the present invention may be used as MC2R antagonists with a long residence time at the receptor. Compounds of the present invention may be used in the treatment of a disease or disorder associated with MC2R. Compounds of the present invention may be used in the treatment of a disease or disorder that would benefit from the modulation of MC2R activity. Compounds of the present invention may be used in the manufacture of medicaments. The compounds or medicaments may be for use in treating, preventing, ameliorating, controlling or reducing the risk of diseases or disorders in which MC2R is involved. Compounds of the present invention may be for use as a single agent or in combination with one or more additional pharmaceutical agents.

[0015] Compounds of the present invention may be useful in the treatment of congenital adrenal hyperplasia (CAH), Cushing’s disease, ectopic ACTH syndrome (or ectopic Cushing’s syndrome), polycystic ovary syndrome (PCOS), depressive illness, septic shock, and disorders or symptoms related thereto.

[0016] DETAILED DESCRIPTION OF THE INVENTION

[0017] The invention relates to novel compounds. The invention also relates to the use of novel compounds as modulators of the melanocortin subtype-2 receptor (MC2R), in particular as MC2R antagonists. The invention further relates to novel compounds as MC2R anatagonists which have a long residence time at the receptor. The invention further relates to the use of novel compounds in the manufacture of medicaments for use as MC2R antagonists. The invention further relates to compounds, compositions and medicaments that may be useful in the treatment of a disease or disorder characterised by activation of the MC2R receptor.

[0018] Provided is a compound of Formula (1):

[0019] or a pharmaceutically acceptable salt thereof.

[0020] Also provided is a compound of Formula (2): or a pharmaceutically acceptable salt thereof.

[0021] Also provided is a pharmaceutical composition comprising a compound of Formula (1) or Formula (2) or pharmaceutically acceptable salts thereof, wherein the compound is present in a stereoisomeric purity of at least 70%, 80%, 90%, 95%, 96%, 97%, 98%, 99% or 99.5%.

[0022] Also provided is a pharmaceutical composition comprising a compound of Formula (1) or Formula (2) or pharmaceutically acceptable salts thereof, wherein the compound is present in a diastereomeric excess (de) of at least 70%, 80%, 90%, 95%, 96%, 97%, 98%, 99% or 99.5%.

[0023] Also provided is a pharmaceutical composition comprising a compound of Formula (1) or Formula (2) or pharmaceutically acceptable salts thereof, wherein the compound is present in an enantiomeric excess (ee) of at least 70%, 80%, 90%, 95%, 96%, 97%, 98%, 99% or 99.5%. Also provided is a pharmaceutical composition comprising a compound of Formula (1) or Formula (2) or pharmaceutically acceptable salts thereof, wherein the compound is present in a diastereomeric excess (de) of at least 98% and an enantiomeric excess (ee) of at least 98%.

[0024] Also provided is a pharmaceutical composition comprising a compound of Formula (1) or Formula (2) or pharmaceutically acceptable salts thereof, wherein the compound is present in a diastereomeric excess (de) of at least 99% and an enantiomeric excess (ee) of at least 99%.

[0025] Also provided is a pharmaceutical composition comprising a compound of Formula (1) or Formula (2) or pharmaceutically acceptable salts thereof, wherein the compound is present in a diastereomeric excess (de) of at least 99.5% and an enantiomeric excess (ee) of at least 99.5%.

[0026] In some embodiments, the compound is present in the form of a pharmaceutically acceptable salt.

[0027] In some embodiments, the compound / pharmaceutical composition is formulated for administration in the form of a tablet, capsule, granules, intramuscular injection or intravenous injection. The compound / pharmaceutical composition may be formulated for oral delivery. The compound / pharmaceutical composition may be administered in the form of a tablet, capsule, granules, intramuscular injection or intravenous injection. The compound / pharmaceutical composition may be administered orally.

[0028] In some embodiments, the pharmaceutical composition further comprises a pharmaceutically acceptable diluent, carrier or excipient. The pharmaceutically acceptable diluent, carrier or excipient may be selected from: a solubilising agent, diluent, lubricant, binding agent, disaggregating agent, pigment, wetting agent, matrix polymer, carrier, shell, lipophilic liquid vehicle, semi-solid lipophilic vehicle, surfactant and an emulsifier.

[0029] The pharmaceutical composition may be provided in the form of a capsule, including shells (e.g. gelatin or hydroxypropyl methylcellulose (HPMC)), solid fill capsules and liquid fill capsules, and may comprise a lipophilic liquid vehicle (e.g. refined oils, triglycerides), a semisolid lipophilic vehicle (e.g. hydrogenated oils, cetostearyl / cetyl / stearyl alcohols, glyceryl esters, TPGS, polyoxylglycerides), a solubilizer, a surfactant or an emulsifier (e.g. Tween 80, poloxamers). The pharmaceutical composition may be provided in the form of a tablet, which may comprise a solid oral excipient, including solubilising agents (e.g. cyclodextrins or modified cyclodextrins), diluents (e.g. lactose, dextrose, saccharose, cellulose, corn starch or potato starch), lubricants (e.g. silica, talc, stearic acid, magnesium or calcium stearate, and / or polyethylene glycols), binding agents (e.g. starches, arabic gums, gelatin, methylcellulose, carboxymethylcellulose or polyvinyl pyrrolidone), disaggregating agents (e.g. starch, alginic acid, alginates or sodium starch glycolate), pigments (e.g. iron oxides), wetting agents (e.g. lecithin, polysorbates, laurylsulphates), acid-resistant polymers or matrix polymers (e.g. hydroxypropyl methylcellulose phthalate, polyvinyl acetate phthalate, hydroxypropyl methylcellulose acetate, hydroxypropyl methylcellulose acetate succinate, alginate, carboxymethyl cellulose, carboxymethyl cellulose, methacrylic acid copolymers, shellac, cellulose acetate phthalate, hydroxypropyl cellulose acetate phthalate, cellulose acetate terephthalate, methyl cellulose acetate phthalate, cellulose acetate isophthalate, cellulose acetate trimellitate).

[0030] The pharmaceutical composition may be provided in the form of an oral liquid, which may comprise a solubilising agent (e.g. cyclodextrins or modified cyclodextrins), or carrier (e.g saccharose or saccharose with glycerine and / or mannitol and / or sorbitol, natural gum, agar, sodium alginate, pectin, methylcellulose, carboxymethylcellulose, or polyvinyl alcohol).

[0031] The pharmaceutical composition may be provided in the form of an intramuscular injection, which may comprise a carrier (e.g. sterile water, olive oil, ethyl oleate, glycols, e.g. propylene glycol) or a solubilising agent (e.g. cyclodextrins or modified cyclodextrins).

[0032] The pharmaceutical composition may be provided in the form of an intravenous Injection, which may comprise a carrier (e.g. sterile water) or a solubilising agent (e.g. cyclodextrins or modified cyclodextrins).

[0033] The compound or pharmaceutically acceptable salt thereof may be administered in any effective therapeutic amount. The compound may be administered at a dose of 1-150 mg (for the purposes of the dose, when the compound is a salt, the mass of the active agent is only considered and so the counter ion is not considered as part of the dose mass). The compound may be administered at a dose of 5-60 mg (e.g. 5-50 mg, 5-40 mg, 5-30 mg, 10-60 mg, 10-50 mg, 10-40 mg, 10-30 mg, 20-60 mg, 20-50 mg, 20-40 mg, 20-30 mg, 30-60 mg, 30-50 mg, 30-40 mg). The compound may be administered at a dose of 20-50 mg. The compound may be administered at a dose of 0.01-3 mg / kg. The compound may be administered at a dose of 0.1-2 mg / kg. The compound may be administered at a dose of 0.2-1 mg / kg (e.g. 0.2-0.9 mg / kg, 0.2-0.8 mg / kg, 0.2-0.7 mg / kg, 0.2-0.6 mg / kg, 0.2-0.5 mg / kg, 0.2-0.4 mg / kg, 0.2-0.3 mg / kg, 0.3-0.9 mg / kg, 0.3-0.8 mg / kg, 0.3-0.7 mg / kg, 0.3-0.6 mg / kg, 0.3-0.5 mg / kg, 0.3-0.4 mg / kg).

[0034] Further embodiments of the invention include the use of a compound of Formula (1) or Formula (2) or pharmaceutically acceptable salts thereof or a pharmaceutical composition comprising a compound of Formula (1) or Formula (2) or pharmaceutically acceptable salts thereof in therapy. Also included is the use of a compound of Formula (1) or Formula (2) or pharmaceutically acceptable salts thereof or a pharmaceutical composition comprising a compound of Formula (1) or Formula (2) or pharmaceutically acceptable salts thereof as a melanocortin subtype-2 receptor (MC2R) modulator. Compounds of the present invention may be used as MC2R receptor modulators. Compounds of the present invention may be used as MC2R receptor inhibitors or antagonists. Compounds of the present invention may be used in the treatment of a disease or disorder characterised by activation of MC2R. Compounds of the present invention may be used in the treatment of a disease or disorder associated with MC2R or in the treatment of a disease or disorder that would benefit from the modulation of MC2R activity.

[0035] Compounds of the present invention may be used in the treatment of congenital adrenal hyperplasia (CAH), Cushing’s disease, ectopic ACTH syndrome, polycystic ovary syndrome (PCOS), depressive illness, septic shock and disorders or symptoms related thereto.

[0036] In some embodiments, compounds and compositions detailed herein are used as modulators of MC2R. Provided herein is a method of treating a disease in an individual comprising administering an effective amount of a compound of Formula (1) or Formula (2) or any embodiment, variation or aspect thereof.

[0037] Compounds as MC2R modulators as disclosed herein can be useful as a prophylactic or therapeutic agent for MC2R associated diseases. In some embodiments, a compound or salt thereof described herein or a composition described herein may be used in a method of treating Cushing’s disease in an individual.

[0038] Also provided are combinations comprising a compound of the present invention and a Corticotropin-releasing factor receptor-1 (CRFi) antagonist. In the combinations the CRFi antagonist may be selected from the group consisting of tildacerfont, crinecerfont, NBI-27914, CP-316,311 , NBI-462000, DMP696, pexacerfont, NBI-35965, ONO-2333MS, antalarmin, NBI- 34041 , DMP904, NBI-30775, SSR125543, NBI-77860, GSK876008,

[0039] CRA5626 / JNJ19567470 / R317573, NBI-76169, verucerfont, and CP-154,526.

[0040] In the combinations the CRFi antagonist may be selected from:

[0041] Also provided are combinations comprising a compound of the present invention and an ACTH antibody. In the combinations the ACTH antibody may be ALD1613 (Feldhaus et al. Endocrinology, Jan 2017, 158(1): 1-8).

[0042] The combinations may be used in the treatment of congenital adrenal hyperplasia (CAH), Cushing’s disease, ectopic ACTH syndrome, polycystic ovary syndrome (PCOS), depressive illness, septic shock and disorders or symptoms related thereto.

[0043] Also provided herein are uses of a compound described herein or a pharmaceutically acceptable salt thereof, or a pharmaceutical composition described herein, in the manufacture of a medicament. In some embodiments, the manufacture of a medicament is for the treatment of a disorder or disease described herein. In some embodiments, the manufacture of a medicament is for the prevention and / or treatment of a disorder or disease mediated by MC2R.

[0044] In some embodiments, a compound or pharmaceutically acceptable salt thereof described herein or a composition described herein may be used in a method as either a stand-alone therapy, or as a conjunctive therapy with other agents that are either palliative (e.g., agents that relieve the symptoms of the disorder to be treated), and / or agents that target the etiology of the disorder. Compounds or compositions of the present invention may be used or administered in combination with a second therapeutic agent.

[0045] In some embodiments, (a) a compound described herein, or a pharmaceutically acceptable salt thereof, or a pharmaceutical composition described herein and (b) an agent are sequentially administered, concurrently administered or simultaneously administered. In certain embodiments, (a) a compound described herein, or a pharmaceutically acceptable salt thereof, or a pharmaceutical composition described herein and (b) an agent are administered with a time separation of about 15 minutes or less, such as about any of 10, 5, or 1 minutes or less. In certain embodiments, (a) a compound described herein, or a pharmaceutically acceptable salt thereof, or a pharmaceutical composition described herein and (b) an agent are administered with a time separation of about 15 minutes or more, such as about any of 20, 30, 40, 50, 60, or more minutes. Either (a) a compound described herein, or a pharmaceutically acceptable salt thereof, or a pharmaceutical composition described herein and (b) an agent may be administered first. In certain embodiments, (a) a compound described herein, or a pharmaceutically acceptable salt thereof, or a pharmaceutical composition described herein and (b) an agent are administered simultaneously.

[0046] The compounds, pharmaceutical compositions and combinations disclosed herein may be for use in therapy.

[0047] The compounds, pharmaceutical compositions, combinations and / or dosages therof disclosed herein may be for use in the treatment of a disorder associated with ACTH excess or that would benefit from the modulation of MC2R activity.

[0048] The compounds, pharmaceutical compositions, combinations and / or dosages therof disclosed herein may be for use in the treatment of congenital adrenal hyperplasia (CAH), Cushing’s disease, ectopic ACTH syndrome, polycystic ovary syndrome (PCOS), depressive illness, septic shock, or disorders or symptoms related thereto.

[0049] Also provided is a method of treating a disorder associated with ACTH excess or that would benefit from the modulation of MC2R activity in a patient, comprising administering an effective amount of a compound, pharmaceutically acceptable salt or combination as described herein or any embodiment, variation or aspect thereof.

[0050] Also provided is a method of treating congenital adrenal hyperplasia (CAH), Cushing’s disease, ectopic ACTH syndrome, polycystic ovary syndrome (PCOS), depressive illness, septic shock, or disorders or symptoms related thereto in a patient, comprising administering an effective amount of a compound, pharmaceutically acceptable salt or combination as described herein or any embodiment, variation or aspect thereof.

[0051] The compounds, pharmaceutical compositions and combinations disclosed herein may be used in the manufacture of a medicament for the treatment of a disorder associated with ACTH excess or that would benefit from the modulation of MC2R activity. The compounds, pharmaceutical compositions and combinations disclosed herein may be used in the manufacture of a medicament for the treatment of congenital adrenal hyperplasia (CAH), Cushing’s disease, ectopic ACTH syndrome, polycystic ovary syndrome (PCOS), depressive illness, septic shock, or disorders or symptoms related thereto.

[0052] DEFINITIONS

[0053] In this application, the following definitions apply, unless indicated otherwise.

[0054] The term “MC2R modulator” as used herein refers to any compound which binds to and modulates the function of MC2 receptors. The term “modulator” should be interpreted to include modulation by modalities including, but not limited to antagonists.

[0055] The term “treatment”, in relation to the uses of any of the compounds described herein, including those of Formula (1) or Formula (2) is used to describe any form of intervention where a compound is administered to a subject suffering from, or at risk of suffering from, or potentially at risk of suffering from the disease or disorder in question. Thus, the term “treatment” covers both preventative (prophylactic) treatment and treatment where measurable or detectable symptoms of the disease or disorder are being displayed.

[0056] The term “effective therapeutic amount” (for example in relation to methods of treatment of a disease or condition) refers to an amount of the compound which is effective to produce a desired therapeutic effect. For example, if the condition is pain, then the effective therapeutic amount is an amount sufficient to provide a desired level of pain relief. The desired level of pain relief may be, for example, complete removal of the pain or a reduction in the severity of the pain.

[0057] The term “enantiomeric excess” (ee) as used herein, means the excess of one enantiomer relative to another in a sample. For example, a composition comprising with 95% of one enantiomer and 5% of the other has an ee of 90%. A racemic mixture has an ee of 0%, while a single completely pure enantiomer has an ee of 100%.

[0058] The term “diastereomeric excess” (de) as used herein, means the excess of one diastereomer relative to another in a sample. For example, a composition comprising with 95% of one diastereomer and 5% of the other has a de of 90%. A racemic mixture has a de of 0%, while a single completely pure diastereomer has an de of 100%. Chemical terms are all used in their conventional sense (e.g. as defined in the IIIPAC Gold Book), unless indicated otherwise.

[0059] Salts or pharmaceutically acceptable salts that may be mentioned include acid addition salts and base addition salts. Such salts may be formed by conventional means, for example by reaction of a free acid or a free base form of a compound with one or more equivalents of an appropriate acid or base, optionally in a solvent, or in a medium in which the salt is insoluble, followed by removal of said solvent, or said medium, using standard techniques (e.g. in vacuo, by freeze-drying or by filtration). Salts may also be prepared by exchanging a counter-ion of a compound in the form of a salt with another counter-ion, for example using a suitable ion exchange resin.

[0060] Examples of pharmaceutically acceptable salts include acid addition salts derived from mineral acids and organic acids, and salts derived from metals such as sodium, magnesium, potassium and calcium. Further examples of acid addition salts include acid addition salts formed with acetic, 2,2-dichloroacetic, adipic, alginic, aryl sulfonic acids (e.g. benzenesulfonic, naphthalene-2-sulfonic, naphthalene-1 ,5-disulfonic and p-toluenesulfonic), ascorbic (e.g. L- ascorbic), L-aspartic, benzoic, 4-acetamidobenzoic, butanoic, (+) camphoric, camphorsulfonic, (+)-(1S)-camphor-10-sulfonic, capric, caproic, caprylic, cinnamic, citric, cyclamic, dodecylsulfuric, ethane-1 ,2-disulfonic, ethanesulfonic, 2-hydroxyethanesulfonic, formic, fumaric, galactaric, gentisic, glucoheptonic, gluconic (e.g. D-gluconic), glucuronic (e.g. D- glucuronic), glutamic (e.g. L-glutamic), a-oxoglutaric, glycolic, hippuric, hydrobromic, hydrochloric, hydriodic, isethionic, lactic (e.g. (+)-L-lactic and (±)-DL-lactic), lactobionic, maleic, malic (e.g. (-)-L-malic), malonic, (±)-DL-mandelic, metaphosphoric, methanesulfonic (mesylate), 1-hydroxy-2-naphthoic, nicotinic, nitric, oleic, orotic, oxalic, palmitic, pamoic, phosphoric, propionic, L-pyroglutamic, salicylic, 4-amino-salicylic, sebacic, stearic, succinic, sulfuric, tannic, tartaric (e.g.(+)-L-tartaric), thiocyanic, trifluoromethanesulfonate (triflate), undecylenic and valeric acids.

[0061] Also encompassed are any solvates of the compounds and their salts. Preferred solvates are solvates formed by the incorporation into the solid state structure (e.g. crystal structure) of the compounds of the invention of molecules of a non-toxic pharmaceutically acceptable solvent (referred to below as the solvating solvent). Examples of such solvents include water, alcohols (such as ethanol, isopropanol and butanol) and DMSO. Solvates can be prepared by recrystallising the compounds of the invention with a solvent or mixture of solvents containing the solvating solvent. Whether or not a solvate has been formed in any given instance can be determined by subjecting crystals of the compound to analysis using well known and standard techniques such as thermogravimetric analysis (TGA), differential scanning calorimetry (DSC) and X-ray crystallography.

[0062] The solvates can be stoichiometric or non-stoichiometric solvates. Particular solvates may be hydrates, and examples of hydrates include hemihydrates, monohydrates and dihydrates. For a more detailed discussion of solvates and the methods used to make and characterise them, see Bryn et al, Solid-State Chemistry of Drugs, Second Edition, published by SSCI, Inc of West Lafayette, IN, USA, 1999, ISBN 0-967-06710-3.

[0063] The term “pharmaceutical composition” in the context of this invention means a composition comprising an active agent and comprising additionally one or more pharmaceutically acceptable diluents, carriers or excipients. The composition may further contain ingredients selected from, for example, diluents, adjuvants, excipients, vehicles, preserving agents, fillers, disintegrating agents, wetting agents, emulsifying agents, suspending agents, sweetening agents, flavouring agents, perfuming agents, antibacterial agents, antifungal agents, lubricating agents and dispersing agents, depending on the nature of the mode of administration and dosage forms. The compositions may take the form, for example, of tablets, dragees, powders, elixirs, syrups, liquid preparations including suspensions, sprays, inhalants, tablets, lozenges, emulsions, solutions, cachets, granules, capsules and suppositories, as well as liquid preparations for injections, including liposome preparations. Examples of pharmaceutically acceptable excipients include carriers (e.g. a solid, liquid or semi-solid carrier), adjuvants, diluents (e.g solid diluents such as fillers or bulking agents; and liquid diluents such as solvents and co-solvents), granulating agents, binders, flow aids, coating agents, release-controlling agents (e.g. release retarding or delaying polymers or waxes), binding agents, disintegrants, buffering agents, lubricants, preservatives, anti-fungal and antibacterial agents, antioxidants, tonicity-adjusting agents, thickening agents, flavouring agents, sweeteners, pigments, plasticizers, taste masking agents, stabilisers or any other excipients conventionally used in pharmaceutical compositions.

[0064] The compounds of the invention may contain one or more isotopic substitutions, and a reference to a particular element includes within its scope all isotopes of the element. For example, a reference to hydrogen includes within its scope1H,2H (D), and3H (T). Similarly, references to carbon and oxygen include within their scope respectively12C,13C and14C and16O and18O. In an analogous manner, a reference to a particular functional group also includes within its scope isotopic variations, unless the context indicates otherwise. For example, a reference to an alkyl group such as an ethyl group or an alkoxy group such as a methoxy group also covers variations in which one or more of the hydrogen atoms in the group is in the form of a deuterium or tritium isotope, e.g. as in an ethyl group in which all five hydrogen atoms are in the deuterium isotopic form (a perdeuteroethyl group) or a methoxy group in which all three hydrogen atoms are in the deuterium isotopic form (a trideuteromethoxy group). The isotopes may be radioactive or non-radioactive.

[0065] Therapeutic dosages may be varied depending upon the requirements of the patient, the severity of the condition being treated, and the compound being employed. Determination of the proper dosage for a particular situation is within the skill of the art. Generally, treatment is initiated with the smaller dosages which are less than the optimum dose of the compound. Thereafter the dosage is increased by small increments until the optimum effect under the circumstances is reached. For convenience, the total daily dosage may be divided and administered in portions during the day if desired.

[0066] The magnitude of an effective dose of a compound will, of course, vary with the nature of the severity of the condition to be treated and with the particular compound and its route of administration. The selection of appropriate dosages is within the ability of one of ordinary skill in this art, without undue burden. The compound may be administered at a dose as described above. In general, daily dose ranges may be from about 10 pg to about 30 mg per kg body weight of a human and non-human animal, preferably from about 50 pg to about 10 mg per kg of body weight of a human and non-human animal, for example from about 50 pg to about 5 mg per kg of body weight of a human and non-human animal, for example from about 100 pg to about 3 mg per kg of body weight of a human and non-human animal, for example from about 100 pg to about 1 mg per kg of body weight of a human and non-human animal and most preferably from about 100 pg to about 0.5 mg per kg of body weight of a human and non-human animal.

[0067] The term “pharmaceutically acceptable” as used herein means compounds, materials, compositions, and / or dosage forms which are, within the scope of sound medical judgment, suitable for use in contact with the tissues of a subject (e.g. a human subject) without excessive toxicity, irritation, allergic response, or other problem or complication, commensurate with a reasonable benefit / risk ratio. Each excipient must also be “acceptable” in the sense of being compatible with the other ingredients of the formulation.

[0068] Pharmaceutical compositions containing compounds of the Formula (1) or Formula (2) can be formulated in accordance with known techniques, see for example, Remington’s Pharmaceutical Sciences, Mack Publishing Company, Easton, PA, USA. The pharmaceutical compositions can be in any form suitable for oral, parenteral, intravenous, intramuscular, intrathecal, subcutaneous, topical, intranasal, intrabronchial, sublingual, buccal, ophthalmic, otic, rectal, intra-vaginal, or transdermal administration.

[0069] Pharmaceutical dosage forms suitable for oral administration include tablets (coated or uncoated), capsules (hard or soft shell), caplets, pills, lozenges, syrups, solutions, powders, granules, elixirs and suspensions, sublingual tablets, wafers or patches such as buccal patches.

[0070] Tablet compositions can contain a unit dosage of active compound together with an inert diluent or carrier such as a sugar or sugar alcohol, eg; lactose, sucrose, sorbitol or mannitol; and / or a non-sugar derived diluent such as sodium carbonate, calcium phosphate, calcium carbonate, or a cellulose or derivative thereof such as microcrystalline cellulose (MCC), methyl cellulose, ethyl cellulose, hydroxypropyl methyl cellulose, and starches such as corn starch. Tablets may also contain such standard ingredients as binding and granulating agents such as polyvinylpyrrolidone, disintegrants (e.g. swellable crosslinked polymers such as crosslinked carboxymethylcellulose), lubricating agents (e.g. stearates), preservatives (e.g. parabens), antioxidants (e.g. BHT), buffering agents (for example phosphate or citrate buffers), and effervescent agents such as citrate / bicarbonate mixtures. Such excipients are well known and do not need to be discussed in detail here.

[0071] Tablets may be designed to release the drug either upon contact with stomach fluids (immediate release tablets) or to release in a controlled manner (controlled release tablets) over a prolonged period of time or with a specific region of the Gl tract.

[0072] Pharmaceutical compositions typically comprise from approximately 1% (w / w) to approximately 95%, preferably% (w / w) active ingredient and from 99% (w / w) to 5% (w / w) of a pharmaceutically acceptable excipient (for example as defined above) or combination of such excipients. Preferably, the compositions comprise from approximately 20% (w / w) to approximately 90% (w / w) active ingredient and from 80% (w / w) to 10% of a pharmaceutically acceptable excipient or combination of excipients. The pharmaceutical compositions comprise from approximately 1% to approximately 95%, preferably from approximately 20% to approximately 90%, active ingredient. Pharmaceutical compositions according to the invention may be, for example, in unit dose form, such as in the form of ampoules, vials, suppositories, pre-filled syringes, dragees, powders, tablets or capsules. Tablets and capsules may contain, for example, 0-20% disintegrants, 0-5% lubricants, 0-5% flow aids and / or 0-99% (w / w) fillers / or bulking agents (depending on drug dose). They may also contain 0-10% (w / w) polymer binders, 0-5% (w / w) antioxidants, 0-5% (w / w) pigments. Slow release tablets would in addition typically contain 0-99% (w / w) release-controlling (e.g. delaying) polymers (depending on dose). The film coats of the tablet or capsule typically contain 0-10% (w / w) polymers, 0-3% (w / w) pigments, and / or 0-2% (w / w) plasticizers.

[0073] The pharmaceutical formulations may be presented to a patient in “patient packs” containing an entire course of treatment in a single package, usually a blister pack.

[0074] The compounds of the Formula (1) or Formula (2) will generally be presented in unit dosage form and, as such, will typically contain sufficient compound to provide a desired level of biological activity. In general, for oral compositions, a unit dosage form may contain from 1 milligram to 2 grams, more typically 1 milligrams to 0.5 gram, for example 1 milligrams to 0.2 gram, e.g. 1 milligrams to 50 miligrams, of active compound.

[0075] The active compound will be administered to a patient in need thereof (for example a human or animal patient) in an amount sufficient to achieve the desired therapeutic effect (effective amount). The precise amounts of compound administered may be determined by a supervising physician in accordance with standard procedures.

[0076] EXAMPLES

[0077] The invention will now be illustrated, but not limited, by reference to the following examples. Experimental

[0078] LCMS methods

[0079] HPLC Analytical methods

[0080] HPLC purification methods

[0081] SFC purification method

[0082] Abbreviations & Acroynms

[0083] Intermediate 1 Intermediate 2

[0084]

[0085] Cis / trans isomers Example 1

[0086] Intermediate 8 Example 2 Synthesis of rac-benzyl (3S,4S)-1-(2-aminobenzoyl)-2'-(2-ethoxyphenyl)-3-ethyl-6'H- spiro[piperidine-4,5'-[1,7]naphthyridine]-7'(8'H)-carboxylate (Intermediate 1):

[0087] To stirred solution of rac-benzyl (3S,4S)-2'-(2-ethoxyphenyl)-3-ethyl-6'H-spiro[piperidine-4,5'- [1 ,7]naphthyridine]-7'(8'H)-carboxylate (2.5 g, 5.15 mmol) in DMF (20 mL) were added 2H- benzo[d][1 ,3]oxazine-2,4(1 H)-dione (1.68 g, 10.30 mmol) at 0 °C. DMAP (0.314 g, 2.57 mmol) was then added and the mixture was stirred RT for 16 h. The reaction mixture was quenched with water (100 mL) and extracted with EtOAc (2 x 100 mL). The organic layer was dried over anhydrous sodium sulphate and concentrated to dryness. The resulting crude product was purified by silica flash column chromatography using EtOAc-PET ether (0-100%) to yield rac- benzyl (3S,4S)-1-(2-aminobenzoyl)-2'-(2-ethoxyphenyl)-3-ethyl-6'H-spiro[piperidine-4,5'- [1 ,7]naphthyridine]-7'(8'H)-carboxylate (2 g, 3.31 mmol, 64%) (Intermediate 1) as a sticky liquid.

[0088] LCMS: 2.31min, 605.3 [M+H]+, Method F

[0089] Synthesis of rac-benzyl (3S,4S)-1-benzoyl-2'-(2-ethoxyphenyl)-3-ethyl-2-methoxy-6'H- spiro[piperidine-4,5'-[1,7]naphthyridine]-7'(8'H)-carboxylate (Intermediate 2):

[0090] To stirred solution of rac-benzyl (3S,4S)-1-(2-aminobenzoyl)-2'-(2-ethoxyphenyl)-3-ethyl-6'H- spiro[piperidine-4,5'-[1 ,7]naphthyridine]-7'(8'H)-carboxylate (5.0 g, 8.27 mmol) (Intermediate 1) in MeOH (20 mL) were added NaNC>2 (0.570 g, 8.27 mmol) at 0 °C. After 15 minutes, 10% cone. HCI in Methanol (90 mL, 248 mmol) and CuCl2 (1.637 g, 16.54 mmol) were added at same temperature. The reaction mixture was warmed to RT and stirred for 3 h. The reaction mixture was quenched with solid NaHCOs and concentrated under reduced pressure. The resulting residue was diluted with water (100 mL) and extracted with EtOAc (2 x 300 mL). The organic layer dried over anhydrous sodium sulphate, filtered and concentrated under reduced pressure to get rac-benzyl (3S,4S)-1-benzoyl-2'-(2-ethoxyphenyl)-3-ethyl-2-methoxy-6'H- spiro[piperidine-4,5'-[1 ,7]naphthyridine]-7'(8'H)-carboxylate (3.5 g, 3.95 mmol, 48%) (Intermediate 2) as a yellow solid, which was used in the next step without any further purification. Note that the corresponding hydroxyl product was also observed in LCMS.

[0091] LCMS: 2.40 to 2.67min, 620.3 & 606.3 [M+H]+, Method AA

[0092] Synthesis of rac-benzyl (S)-1-benzoyl-2'-(2-ethoxyphenyl)-5-ethyl-2,3-dihydro-1 H,6'H- spirolpyridine-^S'-n. JnaphthyridineJ- XS'l-Q-carboxylate (Intermediate 3):

[0093] To stirred solution of rac-benzyl (3S,4S)-1-benzoyl-2'-(2-ethoxyphenyl)-3-ethyl-2-methoxy- 6'H-spiro[piperidine-4,5'-[1 ,7]naphthyridine]-7'(8'H)-carboxylate (4.0 g, 6.45 mmol) (intermediate 2) in THF (40 mL) was added aq HCI (1.18 g, 32.3 mmol) at 0 °C. The mixture was warmed to RT and stirred for 16 h. The reaction mixture was quenched with sat. NaHCOs (50 mL) and extracted with EtOAc (2 x 50 mL). The organic layer was dried over anhydrous sodium sulphate, filtered and concentrated under reduced pressure. The resulting crude product was purified by silica flash column chromatography using EtOAc / PET-ether (0 to 100%) as eluent to yield rac-benzyl (S)-1-benzoyl-2'-(2-ethoxyphenyl)-5-ethyl-2,3-dihydro- 1 H,6'H-spiro[pyridine-4,5'-[1 ,7]naphthyridine]-7'(8'H)-carboxylate (2.2 g, 3.63 mmol, 56%) (Intermediate 3) a white solid.

[0094] LCMS: 2.38 min, 588.4 [M+H]+, Method AC Synthesis of rac-benzyl (4S)-1-benzoyl-2'-(2-ethoxyphenyl)-3-ethyl-6'H- spiro[piperidine-4,5'-[1,7]naphthyridine]-7'(8'H)-carboxylate (Intermediate 4):

[0095] To stirred solution of rac-benzyl (S)-1-benzoyl-2'-(2-ethoxyphenyl)-5-ethyl-2,3-dihydro- 1 H,6'H-spiro[pyridine-4,5'-[1 ,7]naphthyridine]-7'(8'H)-carboxylate (500 mg*4, 0.851 mmol) (intermediate 3) in IPA (10 mL) was added phenyl silane (921 mg, 8.51 mmol). The mixture was degassed for 5 min at N2 atmosphere, then terf-butyl hydroperoxide (TBHP) (548 mg, 4.25 mmol) and Mn(dpm)s (519 mg, 0.851 mmol) was added. The mixture was stirred RT for 20 h. The reaction mixture was quenched with NH4CI solution (50 mL) and extracted with EtOAc (2 x 50 mL). The organic layer was dried over anhydrous sodium sulphate, filtered and concentrated under reduced pressure. The resulting crude product was purified by silica flash column chromatography using EtOAc / PET-ether (0 to 100%) as eluent to afford rac-benzyl (4S)-1-benzoyl-2'-(2-ethoxyphenyl)-3-ethyl-6'H-spiro[piperidine-4,5'-[1 ,7]naphthyridine]- 7'(8'H)-carboxylate (250 mg*4, 0.424 mmol, 50%) (Intermediate 4) as a white solid.

[0096] LCMS: 2.394 min, 590.3 [M+H]+, Method F

[0097] Synthesis of rac-((4S)-2'-(2-ethoxyphenyl)-3-ethyl-7,,8'-dihydro-6,H-spiro[piperidine- 4,5'-[1 ,7]naphthyridin]-1 -yl)(phenyl)methanone (Intermediate 5):

[0098] To stirred solution of rac-benzyl (4S)-1-benzoyl-2'-(2-ethoxyphenyl)-3-ethyl-6'H- spiro[piperidine-4,5'-[1 ,7]naphthyridine]-7'(8'H)-carboxylate (600 mg*2 1.017 mmol) (Intermediate 4) dissolved in EtOAc (20 mL)) was added 10% Pd / C (650 mg, 0.610 mmol). The reaction mixture was stirred under H2 atmosphere at RT for 16 h. The reaction mixture was filtered through celite and washed with EtOAc. The filtrate was evaporated to afford rac- ((4S)-2'-(2-ethoxyphenyl)-3-ethyl-7',8'-dihydro-6'H-spiro[piperidine-4,5'-[1 ,7]naphthyridin]-1- yl)(phenyl)methanone (500 mg*2, 0.988 mmol, 97 %) (Intermediate 5) as a sticky solid.

[0099] LCMS: 1.445 min, 456.6 [M+H]+, Method F

[0100] Synthesis of tert-butyl (2R)-2-(((4SR)-1-benzoyl-2'-(2-ethoxyphenyl)-3-ethyl-6'H- spiro[piperidine-4,5'-[1,7]naphthyridin]-7'(8'H)-yl)methyl)pyrrolidine-1 -carboxylate (intermediate 6):

[0101] To stirred solution of rac-((4S)-2'-(2-ethoxyphenyl)-3-ethyl-7',8'-dihydro-6'H-spiro[piperidine- 4,5'-[1 ,7]naphthyridin]-1-yl)(phenyl)methanone (0.5 g*2, 1.097 mmol) (Intermediate 5) in DOM (10 mL)) was added terf-butyl(R)-2-formylpyrrolidine-1-carboxylate (0.417 mL, 2.195 mmol) at RT and stirred for 30 min at RT. Then Na(OAc)sBH (0.463 g, 2.195 mmol) was added and the mixture stirred at RT for 24 h. The reaction mixture was quenched with saturated aqueous NaHCOs solution (15mL) and extracted with DCM ( 3 x 20 mL). The combined organic layer washed with brine solution (20mL) and concentrated under reduced pressure. The resulting crude product was purified by silica flash column chromatography using EtOAc / Hexane (20 to 50%) as eluent to obtain terf-butyl (2R)-2-(((4SR)-1-benzoyl-2'-(2-ethoxyphenyl)-3-ethyl-6'H- spiro[piperidine-4,5'-[1 ,7]naphthyridin]-7'(8'H)-yl)methyl)pyrrolidine-1 -carboxylate (370 mg*2, 0.492 mmol, 44.9 %) (Intermediate 6) as pale yellow solid.

[0102] LCMS: 2.007 min, 639.4 [M+H]+, Method F

[0103] Synthesis of tert-butyl tert-butyl (2R)-2-(((4S)-2'-(2-ethoxyphenyl)-3-ethyl-6'H- spiro[piperidine-4,5'-[1,7]naphthyridin]-7'(8'H)-yl)methyl)pyrrolidine-1 -carboxylate (Intermediate 7):

[0104] To stirred solution of tert-butyl (2R)-2-(((4SR)-1-benzoyl-2'-(2-ethoxyphenyl)-3-ethyl-6'H- spiro[piperidine-4,5'-[1 ,7]naphthyridin]-7'(8'H)-yl)methyl)pyrrolidine-1 -carboxylate (600 mg*2, 1.017 mmol) (Intermediate 6) in EtOH (6.0 mL) at 27 °C, 2M NaOH (6.64 mL, 6.64 mmol) added The reaction mixture was stirred at 90 °C for 40 h. The reaction mixture was quenched with NH4CI (100 mL) and extracted with EtOAc (2 x 200 mL). The combined organic extracts were washed with brine (100 mL), dried over sodium sulphate and evaporated to yield tertbutyl (2R)-2-(((4S)-2'-(2-ethoxyphenyl)-3-ethyl-6'H-spiro[piperidine-4,5'-[1 ,7]naphthyridin]- 7'(8'H)-yl)methyl)pyrrolidine-1-carboxylate (400 mg, 1.139 mmol) (intermediate 7) as a sticky solid.

[0105] LCMS: 1.556 to 1.600 min, 535.3 [M+H]+, Method F

[0106] Synthesis of tert-butyl (2R)-2-(((4SR)-1-(5-chloro-3-cyanopyridin-2-yl)-2'-(2- ethoxyphenyQ-S-ethyl-e'H-spirolpiperidine-^S'-n. JnaphthyridinJ- 'fS'H)- yl)methyl)pyrrolidine-1 -carboxylate (Intermediate 8):

[0107] To stirred solution of terf-butyl (2R)-2-(((4SR)-2'-(2-ethoxyphenyl)-3-ethyl-6'H- spiro[piperidine-4,5'-[1 ,7]naphthyridin]-7'(8'H)-yl)methyl)pyrrolidine-1 -carboxylate (400 mg*2, 0.748 mmol) (Intermediate 7) in IPA (10 mL) at RT were added DIPEA (0.327 mL, 1.870 mmol) and 2,5-dichloronicotinonitrile (155 mg, 0.898 mmol). The reaction mixture was stirred at 85 °C for 24 h. Both reactions were then combined and concentrated to dryness. The resulting residue was purified by silica flash column chromatography using EtOAc / PET-ether (0 to 100%) as eluent to afford terf-butyl (2R)-2-(((4SR)-1-(5-chloro-3-cyanopyridin-2-yl)-2'-(2- ethoxyphenyl)-3-ethyl-6'H-spiro[piperidine-4,5'-[1 ,7]naphthyridin]-7'(8'H)- yl)methyl)pyrrolidine-1-carboxylate (480 mg, 0.350 mmol, 47 %) (Intermediate 8) as a stick white solid.

[0108] LCMS: 2.330 to 2.379 min, 671 .3 [M+H]+, Method F

[0109] Synthesis of 5-chloro-2-((3R*,4S*)-2'-(2-ethoxyphenyl)-3-ethyl-7'-(((R)-pyrrolidin-2- yl)methyl)-7',8'-dihydro-6'H-spiro[piperidine-4,5'-[1,7]naphthyridin]-1-yl)nicotinonitrile (Example 1) and 5-chloro-2-((3R*,4S*)-2'-(2-ethoxyphenyl)-3-ethyl-7'-(((R)-pyrrolidin-2- yl)methyl)-7',8'-dihydro-6'H-spiro[piperidine-4,5'-[1,7]naphthyridin]-1-yl)nicotinonitrile (Example 2):

[0110] To stirred solution of terf-butyl (2R)-2-(((4SR)-1-(5-chloro-3-cyanopyridin-2-yl)-2'-(2- ethoxyphenyl)-3-ethyl-6'H-spiro[piperidine-4,5'-[1 ,7]naphthyridin]-7'(8'H)- yl)methyl)pyrrolidine-1 -carboxylate (450 mg, 0.670 mmol) (intermediate 8) in DCM (5 mL) at 0 °C was added TFA (382 mg, 3.35 mmol) The reaction mixture was stirred at RT for 16 h and then concentered under reduced pressure. The resulting residue was quenched with 20% aqueous NaHCOs solution (50 mL) and extracted with DCM (2 x 100 mL). The combined organic extracts were washed with brine (50 mL), dried over sodium sulphate and evaporated. The resulting crude product was purified by prep-HPLC (Method AO). The resulting solid was dissolved in DCM (100 mL), washed with 10% aqueous NaHCOs solution (30 mL), water (20mL), dried over sodium sulphate, evaporated, and lyophilized to afford 5-chloro-2-((4SR)- 2'-(2-ethoxyphenyl)-3-ethyl-7'-(((R)-pyrrolidin-2-yl)methyl)-7',8'-dihydro-6'H-spiro[piperidine- 4,5'-[1 ,7]naphthyridin]-1-yl)nicotinonitrile (300 mg, 0.515 mmol, 77%) as a white solid. Note that the product containd a mixture of 4 diastereoisomers in the core at this point.

[0111] LCMS: 2.03 min, 571 .38 [M+H]+, Method AC

[0112] The white solid was purified by preparative SFC (Method p-SFC). The relevant fractions were concentrated under reduced pressure, the resulting solid dissolved in DCM (50 mL), washed with water (2 x 30mL), dried over sodium sulphate, evaporated, and lyophilized to afford 5- chloro-2-((4RS)-2'-(2-ethoxyphenyl)-3-ethyl-7'-(((R)-pyrrolidin-2-yl)methyl)-7',8'-dihydro-6'H- spiro[piperidine-4,5'-[1 ,7]naphthyridin]-1-yl)nicotinonitrile (2.5 mg, 3.85 pmol, 11 %) (mixture of two enantiomers) and 5-chloro-2-((3R*,4R*)-2'-(2-ethoxyphenyl)-3-ethyl-7'-(((R)-pyrrolidin-2- yl)methyl)-7',8'-dihydro-6'H-spiro[piperidine-4,5'-[1 ,7]naphthyridin]-1 -yl)nicotinonitrile (2.5 mg, 4.16 pmol, 11%) (single enantiomer) and 5-chloro-2-((3R*,4R*)-2'-(2-ethoxyphenyl)-3-ethyl- 7'-(((R)-pyrrolidin-2-yl)methyl)-7',8'-dihydro-6'H-spiro[piperidine-4,5'-[1 ,7]naphthyridin]-1- yl)nicotinonitrile (2.7 mg, 4.49 pmol, 12%) (single enantiomer) as white solids.

[0113] 5-chloro-2-((4RS)-2'-(2-ethoxyphenyl)-3-ethyl-7'-(((R)-pyrrolidin-2-yl)methyl)-7',8'-dihydro- 6'H-spiro[piperidine-4,5'-[1 ,7]naphthyridin]-1 -yl)nicotinonitrile (2.5 mg, 3.85 pmol, 11 %) (mixture of two enantiomers) was again purified by preparative SFC (Method p-SFC). The prep fractions were evaporated. The resulting residue was dissolved in DCM (50 mL), washed with water (2 x 30 mL), dried over sodium sulphate, evaporated, and lyophilized to afford 5- chloro-2-((3R*,4S*)-2'-(2-ethoxyphenyl)-3-ethyl-7'-(((R)-pyrrolidin-2-yl)methyl)-7',8'-dihydro- 6'H-spiro[piperidine-4,5'-[1 ,7]naphthyridin]-1 -yl)nicotinonitrile (14 mg, 0.025 mmol, 19%) (Example 1) and 5-chloro-2-((3R*,4S*)-2'-(2-ethoxyphenyl)-3-ethyl-7'-(((R)-pyrrolidin-2- yl)methyl)-7',8'-dihydro-6'H-spiro[piperidine-4,5'-[1 ,7]naphthyridin]-1 -yl)nicotinonitrile (20 mg 0.034 mmol, 26%) (Example 2) as a white solids.

[0114] Analytical data for Example 1 and 2 can be found in Table 1 below.

[0115] Table 1 : Analytical Data for Example 1 and 2

[0116] * At present, only the relative stereochemistry of the core has been determined for Example 1 and 2. If Example 1 has Formula (1), Example 2 has Formula (2) and vice versa.

[0117] BIOLOGICAL ACTIVITY

[0118] Terbium labelling and preparation of SNAP-tagged MC2 membranes

[0119] Cells were labelled with 100 nM of SNAP-Lumi4-Tb and incubated for 1 h at 37 °C under 95% air / 5% CO2 atmosphere prior to harvesting and pelleting by centrifugation at 3 min at 1200 rpm. Cell pellets were homogenized using an FastPrep-24 5G homogeniser (MP Biomedicals) and subsequently centrifuged and resuspended twice at 22,000xg at 4 °C (Eppendorf Centrifuge) for 30 min. The final pellet was resuspended in 10 mM HEPES and 0.1 mM EDTA, pH 7.4, at a concentration of 5-10 mg ml’1and stored at -20°C for later use.

[0120] Fluorescent Ligand Binding Assays

[0121] All fluorescent ligand binding experiments were performed with a Cy5-labelled small molecule MC2 antagonist in 384-well Optiplate low-binding plates in 1x Tag-lite buffer (PerkinElmer), with 2% DMSO, 0.04% pluronic acid and 100pg ml’1saponin. In all cases, non-specific binding was determined in the presence of 1 pM unlabelled MC2 antagonist. Signal detection was performed on a Pherastar FSX (BMG Labtech, Germany) using standard HTRF settings and the HTRF ratios were calculated by dividing the acceptor signal (665nm) by the donor signal (620nm) and multiplying the value by 10,000.

[0122] TR-FRET Competitive Equilibrium Binding Assay

[0123] To determine the equilibrium dissociation constant (K,) of competing test compounds, MC2 membranes (2pg per well) were incubated with a range of concentrations of test compounds in the presence of 50nM fluorescent tracer. HTRF ratios were obtained after overnight incubation at 25°C to ensure equilibrium had been reached.

[0124] TR-FRET Competitive Binding Kinetic Assay

[0125] To determine the association (kon) and dissociation (koff) rates of unlabelled compounds, a competitive kinetic binding assay was performed which involved the simultaneous addition of 50nM fluorescent tracer and increasing concentrations of competing ligand to MC2 membranes (2pg per well). The degree of bound fluorescent tracer at MC2 was determined at multiple timepoints by HTRF.

[0126] In parallel, the association (kon) and dissociation (kOff) rates for the fluorescent tracer were determined through incubation of increasing concentrations of fluorescent tracer with MC2 membranes in the absence and presence of 1 pM unlabelled MC2 antagonist. The degree of bound fluorescent tracer was calculated at multiple timepoints by HTRF detection and association kinetic curves were generated. The resulting data were globally fitted to the association kinetic model (Prism 8.0, GraphPad, San Diego, USA) to derive a best-fit estimate for konand kOft as described under data analysis. From these data an estimate for the equilibrium dissociation constant (Kd) could be calculated.

[0127] Competition kinetic data and fluorescent tracer kinetic parameters were fit globally to the equation first described by Motulsky and Mahan (Mol. Pharmacol., 1984, 25, 1-9) to determine unlabelled compound konand kOff.

[0128] Table 2: Equilibrium and kinetic binding data of Example 1 and 2

[0129] * At present, only the relative stereochemistry of the core has been determined for Example 1 and 2. Example 1* in Table 2 corresponds to Example 1* in Table 1 and the same for Example 2*. cAMP accumulation assay

[0130] Chinese hamster ovary (CHO) cells, stably expressing human or rat MC2 with MRAP, were maintained in DMEM / F12 cell culture medium supplemented with 10% fetal bovine serum and 1% L-glutamine. On the day of experimentation, cells were plated at 10000 cells / well in white low-volume 384-well plates in assay buffer (Hank’s balanced salt solution containing 5 mM HEPES (pH 7.4) with 0.01% w / v BSA and 500 pM 3-isobutyl-1 -methylxanthine) before being incubated with a range of concentrations of MC2 compounds for 2h at 37°C, 5% CO2. After 2h, increasing concentrations of ACTH 1-24 were added to the cells for a set duration, before lysis and cAMP detection using the homogeneous time resolved fluorescence (HTRF) cAMP Gs HiRange kit (CisBio) according to the manufacturer’s instructions. Fluorescence resonance energy transfer (FRET) levels were detected on a PHERAstar plate reader (BMG), and data interpolated from a cAMP standard curve, and analysed using GraphPad Prism 8 (GraphPad). In this assay format, Example 2 shows a reduction in Emax of ACTH 1-24 in an in vitro cAMP accumulation assay, consistent with an insurmountable antagonist behaviour (Figure 1).

[0131] Brief Description of the Figures

[0132] Figure 1 : Antagonism of ACTH 1-24 cAMP by Example 2 at increasing concentrations over their Ki value showing functional insurmountability. Data are normalized to a percentage of the cAMP produced by 500nM ACTH 1-24. Data are mean ± SD from duplicate determinations in a single experiment.

Claims

CLAIMS1. A compound of Formula (1) or (2):or a pharmaceutically acceptable salt thereof.

2. The compound according to claim 1, which is a compound of Formula (1):or a pharmaceutically acceptable salt thereof.

3. The compound according to claim 1, which is a compound of Formula (2):or a pharmaceutically acceptable salt thereof.

4. A pharmaceutically acceptable salt of a compound according to any one of claims 1 to 3.

5. The compound or pharmaceutically acceptable salt according to any one of claims 1 to 4, which is formulated for oral delivery.

6. The compound or pharmaceutically acceptable salt according to any one of claims 1 to 4, which is administered in the form of tablet, capsule, granules, intramuscular injection or intravenous injection.

7. The compound or pharmaceutically acceptable salt according to any one of claims 1 to 6, further comprising a pharmaceutically acceptable diluent, carrier or excipient.

8. The compound or pharmaceutically acceptable salt according to claim 7, wherein the pharmaceutically acceptable excipient is selected from: a solubilising agent, diluent, lubricant, binding agent, disaggregating agent, pigment, wetting agent, matrix polymer, carrier, shell, lipophilic liquid vehicle, semi-solid lipophilic vehicle, surfactant and an emulsifier.

9. The compound or pharmaceutically acceptable salt according to any one of claims 1 to 8, wherein the compound is administered at a dose of 1-150, 10-100 or 20-50 mg.

10. The compound or pharmaceutically acceptable salt according to any one of claims 1 to 8, wherein the compound is administered at a dose of 20-50 mg.

11. A combination comprising a compound or pharmaceutically acceptable salt according to any one of claims 1 to 10 and a CRF1 antagonist.

12. A combination comprising a compound or pharmaceutically acceptable salt according to any one of claims 1 to 10 and an ACTH antibody.

13. The compound, pharmaceutically acceptable salt or combination according to any one of claims 1 to 12 for use in therapy.

14. The compound, pharmaceutically acceptable salt or combination according to any one of claims 1 to 12 for use in the treatment of a disorder associated with ACTH excess or that would benefit from the modulation of MC2R activity.

15. The compound, pharmaceutically acceptable salt or combination according to any one of claims 1 to 12 for use in the treatment of congenital adrenal hyperplasia (CAH), Cushing’s disease, ectopic ACTH syndrome, polycystic ovary syndrome (PCOS), depressive illness, septic shock, or disorders or symptoms related thereto.

16. A method of treating a disorder associated with ACTH excess or that would benefit from the modulation of MC2R activity in a patient, comprising administering an effective amount of a compound, pharmaceutically acceptable salt or combination according to any one of claims 1 to 12.

17. A method of treating congenital adrenal hyperplasia (CAH), Cushing’s disease, ectopic ACTH syndrome, polycystic ovary syndrome (PCOS), depressive illness, septic shock, or disorders or symptoms related thereto in a patient, comprising administering an effective amount of a compound, pharmaceutically acceptable salt or combination according to any one of claims 1 to 12.

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