WO2023232830A1

WO2023232830A1 - Boronic acid adducts

Info

Publication number: WO2023232830A1
Application number: PCT/EP2023/064469
Authority: WO
Inventors: Markus B. KLEIN; Holger Kubas; Michael Lange
Original assignee: Merck Patent Gmbh
Priority date: 2022-06-02
Filing date: 2023-05-31
Publication date: 2023-12-07

Abstract

The present invention relates to boronic acid derivatives according to formula (I-a), (I-b), (I-c) or (1-d), or a pharmaceutically acceptable salt thereof. These compounds are useful for inhibiting the activity of immunoproteasome (LMP7) and for the treatment and/or prevention of medical conditions affected by immunoproteasome activity such as inflammatory and autoimmune diseases, neurodegenerative diseases, proliferative diseases and cancer.

Description

Boronic Acid Adducts

Field of the invention

The present invention relates to new a-amino boronic acid derivatives that are useful for inhibiting the activity of immunoproteasome (LMP7) and for the treatment and/or prevention of medical conditions affected by immunoproteasome activity such as inflammatory and autoimmune diseases, neurodegenerative diseases, proliferative diseases and cancer. In particular, the compounds of the present invention release in the presence of aqueous media free a-amino boronic acids which are highly selective inhibitors of the immunoproteasome subunit LMP7. Compared to the free a-amino boronic acids, the derivatives described in the present invention show better properties in terms of crystallinity, homogeneity, stability and shelf-life. Accordingly, the derivatives described in the present invention can be used as produgs.

Background of the invention

The proteasome (also known as macropain, the multicatalytic protease, and 20S protease) is a high molecular weight, multisubunit protease which has been identified in every examined species from an archaebacterium to human. The enzyme has a native molecular weight of approximately 650,000 and, as revealed by electron microscopy, a distinctive cylinder-shaped morphology (Rivett, (1989) Arch. Biochem. Biophys. 268: 1-8; and Orlowski, (1990) Biochemistry 29:10289-10297). The proteasome subunits range in molecular weight from 20,000 to 35,000, and are homologous to one another but not to any other known protease.

The 20S proteasome is a 700 kDa cylindrical-shaped multicatalytic protease complex comprised of 28 subunits, classified as a- and 0-type, that are arranged in 4 stacked heptameric rings. In yeast and other eukaryotes, 7 different a subunits form the outer rings and 7 different 0 subunits comprise the inner rings. The a subunits serve as binding sites for the 19S (PA700) and 1 IS (PR68) regulatory complexes, as well as a physical barrier for the inner proteolytic chamber formed by the two 0 subunit rings. Thus, in vivo, the proteasome is believed to exist as a 26S particle ("the 26S proteasome"). In vivo experiments have shown that inhibition of the 20S form of the proteasome can be readily correlated to inhibition of 26S proteasome.

Cleavage of amino-terminal prosequences of 0 subunits during particle formation expose amino-terminal threonine residues, which serve as the catalytic nucleophiles. The subunits responsible for catalytic activity in proteasome thus possess an amino terminal nucleophilic residue, and these subunits belong to the family of N-terminal nucleophile (Ntn) ATTY REF: 26500-0023 WO 1 hydrolases (where the nucleophilic N-terminal residue is, for example, Cys, Ser, Thr, and other nucleophilic moieties). This family includes, for example, penicillin G acylase (PGA), penicillin V acylase (PVA), glutamine PRPP amidotransferase (GAT), and bacterial glycosylasparaginase. In addition to the ubiquitously expressed 0 subunits, higher vertebrates also possess three interferon- y- inducible 0 subunits (LMP7, LMP2 and MECL1), which replace their normal counterparts, 05, 01 and 02, respectively. When all three IFN- y- inducible subunits are present, the proteasome is referred to as an "immunoproteasome". Thus, eukaryotic cells can possess two forms of proteasomes in varying ratios.

Through the use of different peptide substrates, three major proteolytic activities have been defined for the eukaryote 20S proteasomes: chymotrypsin-like activity (CT-L), which cleaves after large hydrophobic residues; trypsin-like activity (T-L), which cleaves after basic residues; and peptidylglutamyl peptide hydrolyzing activity (PGPH), which cleaves after acidic residues. Two additional less characterized activities have also been ascribed to the proteasome: BrAAP activity, which cleaves after branched-chain amino acids; and SNAAP activity, which cleaves after small neutral amino acids. Although both forms of the proteasome possess all five enzymatic activities, differences in the extent of the activities between the forms have been described based on specific substrates. For both forms of the proteasome, the major proteasome proteolytic activities appear to be contributed by different catalytic sites within the 20S core.

In eukaryotes, protein degradation is predominately mediated through the ubiquitin pathway in which proteins targeted for destruction are ligated to the 76 amino acid polypeptide ubiquitin. Once targeted, ubiquitinated proteins then serve as substrates for the 26S proteasome, which cleaves proteins into short peptides through the action of its three major proteolytic activities. While having a general function in intracellular protein turnover, proteasome-mediated degradation also plays a key role in many processes such as major histocompatibility complex (MHC) class I presentation, apoptosis and cell viability, antigen processing, NF-KB activation, and transduction of pro- inflammatory signals.

Proteasome activity is high in muscle wasting diseases that involve protein breakdown such as muscular dystrophy, cancer and AIDS. Evidence also suggests a possible role for the proteasome in the processing of antigens for the class I MHC molecules (Goldberg, et al. (1992) Nature 357:375-379).

Proteasomes are involved in neurodegenerative diseases and disorders such as Amyotrophic Lateral Sclerosis (ALS), (J Biol Chem 2003, Allen S et al., Exp Neurol 2005, Puttaparthi k et al.), Sjogren Syndrome (Arthritis & Rheumatism, 2006, Eger er T et al.) , systemic lupus erythematosus and lupus nephritis (SLE/LN), (Arthritis & rheuma 2011, Ichikawa et al., I Immunol, 2010, Lang VR et al., Nat Med, 2008, Neubert K et al), glomerulonephritis (I Am Soc nephrol 2011, Bontscho et al.), Rheumatoid Arthritis (Clin Exp Rheumatol, 2009, Van der Heiden IW et al.), Inflammatory bowel disease (IBD), ulcerative colitis, crohn’s diseases, (Gut 2010, Schmidt N et al., I Immunol 2010, Basler M et al., Clin Exp Immunol, 2009, Inoue S et al.), multiple sclerosis (Eur I Immunol 2008, Fissolo N et al., I Mol Med 2003, Elliott PI et al., I Neuroimmunol 2001, Hosseini et al., I Autoimmun 2000, Vanderlugt CL et al.), Amyotrophic lateral sclerosis (ALS), (Exp Neurol 2005, Puttaparthi k et al., I Biol Chem 2003, Allen S et al.), osteoarthritis (Pain 2011, Ahmed s et al., Biomed Mater Eng 2008, Etienne S et al.), Atherosclerosis (I Cardiovasc Pharmacol 2010, Feng B et al., Psoriasis (Genes & Immunity, 2007, Kramer U et al.), Myasthenia Gravis (I Immunol, 2011, Gomez AM et al.), Dermal fibrosis (Thorax 2011, Mutlu GM et al., Inflammation 2011, Koca SS et al., Faseb I 2006, Fineschi S et al.), renal fibrosis (Nephrology 2011 Sakairi T et al.), cardiac fibrosis (Biochem Pharmacol 2011, Ma y et al.,) Liver fibrosis (Am J Physiol gastrointest Liver Physiol 2006, Anan A et al.), Lung fibrosis (Faseb J 2006, Fineschi S et al et al.), Imunoglobuline A nephropathy (IGa nephropathy), (Kidney Int, 2009, Coppo R et al.), Vasculitis (J Am Soc nephrol 2011, Bontscho et al.), Transplant rejection (Nephrol Dial transplant 2011, Waiser J et al.), Hematological malignancies (Br J Haematol 2011, singh AV et al., Curr Cancer Drug Target 2011, Chen D et al.) and asthma.

Yet, it should be noted that commercially available proteasome inhibitors inhibit both the constitutive and immuno-forms of the proteasome. Even bortezomib, the FDA-approved proteasome inhibitor for the treatment of relapsed multiple myeloma patients, does not distinguish between the two forms (Altun et al, Cancer Res 65:7896, 2005). Furthermore, the use of Bortezomib is associated with a treatment-emergent, painful peripheral neuropathy (PN), this bortezomib- induced neurodegeneration in vitro occurs via a proteasome-independent mechanism and that bortezomib inhibits several nonproteasomal targets in vitro and in vivo (Clin. Cancer Res, 17(9), May 1, 2011).

In addition to conventional proteasome inhibitors, a novel approach may be to specifically target the hematological-specific immunoproteasome, thereby increasing overall effectiveness and reducing negative off-target effects. It has been shown that immunoproteasome-specific inhibitor, could display enhanced efficiency on cells from a hematologic origin (Curr Cancer Drug Targets, 11(3), Mar, 2011).

In recent years much effort has been devoted to provide selective immunoproteasome inhibitors, which could be used as therapeutic agents for the treatment of e.g. SLE or other immune or autoimmune disorders in the context of rheumatoid arthritis. Selective immunoproteasome inhibitors are helpful in order to minimize unwanted side effects mediated by inhibition of the constitutive proteasome or other nonproteasomal targets.

WO 2013/092979 Al describes boronic acid derivatives, which show selectivity towards the inhibition of the LMP7 activity. However, the extent of selectivity, which is achievable with the described types of compounds, is limited, particularly with respect to the split to the inhibitory activity of the constitutive proteasome. Unspecific inhibitors of the proteasome and the immunoproteasome like Bortezomib and Carfilzomib have demonstrated their clinical value in the indication of multiple myeloma. Although this unspecific profile, hitting major components in the immunoproteasome as well as the constitutive proteasome, is regarded beneficial in terms of target inhibition and clinical effectiveness, this unspecific profile limits the clinical applicability of these agents by inducing pronounced side effects like thrombocytopenia, neutropenia as well as peripheral neuropathy. To a certain extent, this side effect profile could be attributed to the broad inhibition of the catalytic activity, especially the combined inhibition of the 135 subunits of the constitutive and the immunoproteasome. The approach to come up with more selective inhibitors of the immunoproteasome (and especially the 135i subunit of the immunoproteasome), in order to reduce major side effects has been described e.g. in 2011 by Singh et al (Br. J. Hematology 152(2): 155-163) for PR-924, a 100 fold selective inhibitor of the LMP7subunit of the immunoproteasome. The authors demonstrated the presence of high expression levels of the immunoproteasome in multiple myeloma. The authors also described the effect of a selective inhibitor of the LMP7 subunit on the induction of cell death in MM cell lines as well as CD138+ MM primary patient cells without decreasing the viability of control PBMC’s of healthy volunteers which can be regarded as a conceptual proof. Beside the concept of a reduced side effect profile for selective 135i inhibitors other group demonstrated the efficacy of selective 135 i inhibition on the viability of Bortezomib resistant cell lines underlining the value and potential perspective for the application of selective LMP7 inhibitors for hematological malignancies (D. Niewerth et al. / Biochemical Pharmacology 89 (2014) 43-51).

W02016/050356, W02016/050355, WO2016/050359, and W02016/050358 describe new boronic acid derivatives, which indeed inhibit the activity of the immunoproteasome (LMP7) and provide a significant split to the inhibitory activity of the constitutive proteasome. In particular in WO2019038250 amino boronic acid derivatives have been disclosed, which are highly selective inhibitors of the immunoproteasome subunit LMP7 and provide an excellent split to the inhibitory activity of the constitutive proteasome. Free boronic acids in amorphous or partially crystallized form as obtained in the aforementioned patent applications however have several flaws: They are often difficult to purify, they can be air sensitive and prone to oxidation by oxygen or other oxidants and may react to boric acid and the corresponding alcohols. They are also known to condense with itself to form anhydride linear dimers, trimers, higher oligomers and cyclic trimers (Boronic Acids. Edited by Dennis G. Hall, Copyright © 2005 WILEY-VCH Verlag, GmbH & Co. KGaA, Weinheim, ISBN 3-527-30991-8).

Insufficient homogeneity, short shelf life, and impurities of boronic acids limit their pharmaceutical utility. Thus, there is a need for additional stable, non toxic formulations of boronic acid derivatives.

Surprisingly it was found that the amino boronic acid derivatives of the present invention can be obtained in homogeneous, crystalline form, with good shelf-life and highly improved stability towards oxidation. These derivatives therefor present a storage form of free boronic acids of formular (P),

which are highly selective inhibitors of the immunoproteasome subunit LMP7, with excellent pharmaceutical utility. Accordingly, the compound of the present invention can be used as prodrugs for the corresponding free boronic acid of formula (P).

Upon treatment with aqueous media these derivatives dissolve and release the parent boronic acid in its free form.

Summary of the Invention The present invention provides a compound according to any one of formulae (I-a), (I-b), (I-c) or (1-d):

or a pharmaceutically acceptable salt thereof, wherein

Z is H or Cl; each instance of R¹, R², R³ and R⁴ is independently selected from the group consisting of hydrogen, methyl, ethyl, isopropyl, -CF3, -CHF2, -CH2F, -CH2OH, -CH2CH2OH, -OH, -F, and -Cl; or two instances of R¹ and R² attached to the same carbon atom are taken together to form a carbonyl; or two instances of R³ and R⁴ attached to the same carbon atom are taken together to form a carbonyl;

R⁵ is absent, hydrogen, methyl or ethyl; and each of R⁶ and R⁷ independently selected from the group consisting of hydrogen, methyl, ethyl, isopropyl, -CF₃, -CHF₂, -CH₂F, -CH₂OH, -CH₂CH₂OH, -OH, -F, and -Cl.

The compounds according to the present invention show good properties in terms of crystallinity, homogeneity, stability and shelf-life. Thus, these compounds can be used as produgs for the corresponding free boronic acid.

Brief Description of the Figures

Figure 1 depicts the X-ray powder diffractogram of Compound 1.

Figure 2 depicts the X-ray powder diffractogram of Compound 2.

Figure 3 depicts the X-ray powder diffractogram of Compound 3.

Figure 4 depicts the X-ray powder diffractogram of Compound 4.

Figure 5 depicts the X-ray powder diffractogram of Compound 5.

Figure 6 depicts the X-ray powder diffractogram of Compound 6.

Figure 7 depicts the X-ray powder diffractogram of Compound 7.

Figure 8 depicts the X-ray powder diffractogram of Compound 8.

Figure 9 depicts the X-ray powder diffractogram of Compound 9.

Figure 10 depicts the X-ray powder diffractogram of Compound 10.

Figure 11 depicts the X-ray powder diffractogram of Compound 11.

Figure 12 depicts the X-ray powder diffractogram of Compound 12.

Figure 13 depicts the X-ray powder diffractogram of Compound 13.

Figure 14 depicts the X-ray powder diffractogram of Compound 16.

Figure 15 depicts x-ray powder diffractograph of the amorphous compound 18.

Figure 16 depicts Water Vapour Sorption behaviour of Compound 18 Figure 17 depicts the DSC scan of Compound 18.

Detailed Description of Certain Embodiments of the Invention

The present invention provides compounds according to formula (I-a), (I-b), (I-c) or (1-d):

or a pharmaceutically acceptable salt thereof, wherein

A specific embodiment concerns a compound according to any one of formulae (I-a), (I- b), (I-c), or (I-d), or a pharmaceutically acceptable salt thereof, wherein Z is hydrogen.

Yet another embodiment concerns a compound according to any one of formulae (I-a), (I- b), (I-c), or (I-d), or a pharmaceutically acceptable salt thereof, wherein Z is -Cl.

In one embodiment, the compound according to any one of formulae (I-a), (I-b) or (I-c), or a pharmaceutically acceptable salt thereof, wherein each instance of R¹, R², R³ and R⁴ and R⁵ (when present) are independently hydrogen or methyl. For clarity, formulae (I-a), (I-b) or (I-c) all contain residues R¹, R², R³ and R⁴, but residue R⁵ is only present in formula (I-c).

Another embodiment concerns a compound according to any one of formulae (I-a), (I-b) or (I-c), or a pharmaceutically acceptable salt thereof, wherein R¹, R², R³, R⁴ and R⁵ (when present) are all hydrogen.

Another embodiment concerns a compound according to any one of formulae (I-a), (I-b) or (I-c), or a pharmaceutically acceptable salt thereof, wherein R¹, R², R³, R⁴ and R⁵ (when present) are all methyl.

In another embodiment, each instance of R¹, R², R³ and R⁴ in formulae (I-a) or (I-b) is independently hydrogen, methyl, CH₂OH, -CH₂CH₂OH or -OH. In a specific aspect of this embodiment one of the residues R¹, R², R³ and R⁴ respresents CH₂OH, -CH₂CH₂OH or -OH and the remaining residues are independently selected from hydrogen and methyl. A further aspect of this embodiment concerns a compound wherein one of the residues R¹, R², R³ and R⁴ respresents CH₂OH, -CH₂CH₂OH or -OH and the remaining residues represent methyl.

One embodiment is a compound according to formula (I-a), or a pharmaceutically acceptable salt thereof, wherein at least one instance of R¹ and R² and/or R³ and R⁴ are taken together with the carbon atom to which they are bound to form a carbonyl. In one aspect of this embodiment, all instances of R¹, R², R³ and R⁴ which are not taken together to form a carbonyl are either hydrogen or methyl. Another specific asepect of this embodiment concerns a compound, wherein all instances of R¹, R², R³ and R⁴, which are not taken together to form a carbonyl are hydrogen. Another specific asepect of this embodiment concerns a compound, wherein one residue of R¹, R², R³ and R⁴, which is not taken together with another residue to form a carbonyl represents a methyl and all remaining residues are hydrogen.

One embodiment of this invention is a compound according to formula (I-b), or a pharmaceutically acceptable salt thereof, wherein R¹, R², R³ and R⁴ are all methyl.

Another embodiment is a compound according to formula (I-b), or a pharmaceutically acceptable salt thereof, wherein R¹ and R² are taken together with the carbon atom to which they are bound to form a carbonyl and R³ and R⁴ are independently either hydrogen or methyl.

Another specific embodiment concerns a compound according to formula (I-c), or a pharmaceutically acceptable salt thereof, wherein all R¹, R², R³ and R⁴ residues represent hydrogen.

Another embodiment is a compound according to formula (I-c), or a pharmaceutically acceptable salt thereof, wherein one instance of R¹ and R² are taken together to form a carbonyl group, the remaining residues R¹ and R² are independently either hydrogen or methyl, and one instance of R³ and R⁴ is methyl and the other of R³ and R⁴ represent hydrogen.

Another embodiment is a compound according to formula (I-c), or a pharmaceutically acceptable salt thereof, wherein on instance of R¹ and R² are taken together to form a carbonyl group and the remaining R¹ and R² residues and all R³ and R⁴ residues are hydrogen. Another embodiment is a compound according to formula (I-c), or a pharmaceutically acceptable salt thereof, wherein one instance of R¹ and R² are taken together to form a carbonyl group and the remaining R¹ and R² residues and all R³ and R⁴ residues are methyl.

Another embodiment concerns a compound according to formula (I-c), or a pharmaceutically acceptable salt thereof, wherein one instances of R¹ and R² attached to the same carbon atom are taken together to form a carbonyl and instances of R³ and R⁴ attached to the same carbon atom are taken together to form a carbonyl and the remaining R¹, R², R³ and R⁴ residues are all either hydrogen or methyl.

For clarity, in embodiments according to formula (I-c) described above, wherein R⁵ is absent, the nitrogen atom is uncharged. In alternate embodiments, wherein R⁵ is -H, methyl or ethyl, the nitrogen atom is positively charged.

Another embodiment of the present invention concerns a compound according to formula (I-d), or a pharmaceutically acceptable salt thereof, wherein the R⁶ is a methyl group and R⁷ is a -CH2OH group.

One embodiment of the invention is a compound selected from Table 1 :

or a pharmaceutically acceptable salt thereof.

In another embodiment of the invention is a crystalline form of any one of compounds of formulae ( (I-a), (I-b), (I-c), or (I-d), or a pharmaceutically acceptable salt, solvate, hydrate, or adduct thereof.

One embodiment of the invention is the crystalline form of any one of Compounds 1-17. In one aspect of this embodiment, is the crystalline form of a compound selected from Compound 1-17, or a pharmaceutically acceptable salt thereof, as characterized by the two most intense 20 peaks of the XRPD spectra shown herein. In another aspect of this embodiment is the crystalline form of a compound selected from Compound 1-17, or a pharmaceutically acceptable salt thereof, as characterized by the three most intense 20 peaks of the XRPD spectra shown herein. In another aspect of this embodiment is the crystalline form of a compound selected from Compound 1-17, or a pharmaceutically acceptable salt thereof, as characterized by the four most intense 20 peaks of the XRPD spectra shown herein. In another aspect of this embodiment is the crystalline form of a compound selected from Compound 1-17, or a pharmaceutically acceptable salt thereof, as characterized by the five most intense 20 peaks of the XRPD spectra shown herein. In another aspect of this embodiment is a crystalline form as shown in any one of Figures 1- 14. Compounds of the present invention are inhibitors of the immunoproteasome subunit LMP7. They show a particularly high selectivity on LMP7 over 05 (cP) and may show beneficial properties in terms of crystallinity, homogeneity, stability and/or shelf life.

It is known that boronic acid derivatives such as compounds of formula (P), form adducts by reaction with aliphatic or aromatic alcohols, diols, sugars, sugar alcohols, a-hydroxy acids or nucleophiles containing one, two or three N-/O-containing functional group (e.g. -NH2, -CONH2 or C=NH, -OH, -COOH) wherin in case that three functional groups are present, one of the three heteroatoms might form a coordinative bond (“Boronic Acids” Edited by Dennis G. Hall, 2^nd Edition, Copyright © 2011 WILEY-VCH Verlag, GmbH & Co. KGaA, Weinheim, ISBN 978-3-527-32598-6; WO2013128419; W02009154737). The adduct formation is particularly fast with preorganized diols.

The FDA/EMA approved drug Ninlaro contains ixazomib citrate. Ixazomib itself is an oral proteasome inhibitor containing a free boronic acid moiety. The active substance, ixazomib citrate, is a crystalline and stable adduct of ixazomib with citric acid and serves as a prodrug of ixazomib. Under physiological, aqueous conditions ixazomib citrate rapidly hydrolyses to ixazomib and citric acid.

While citric acid was useful to form a stable and crystalline prodrug with Ixazomib, several attemps to form similar prodrugs with compound 18 failed. With citric acid only noncrystalline, oily and sticky adducts were obtained (see Example 13) and also the formation of other adducts did not lead to the desired results in terms of yield, homgenity, crystallinity and/or shelf life.

The boronic acid adducts of the present invention provide surprising advantages over the parent boronic acid compounds and the compounds of the present invention can be obtained in homogenous, crystalline form with good shelf-life and highly improved stability towards oxidation. These adducts release the parent boronic acid compounds upon treatment with aqueous media. Therefore, the boronic acid adducts of the present invention present a very stable storage form of the free boronic acids, which are highly selective inhibitors of the immunoproteasome subunit LMP7. As used herein and unless otherwise indicated, the term "prodrug" means a compound that can hydrolyze or otherwise react under aqueous or physiological conditions (in vitro or in vivo) to provide an active compound (in the present case the free boronic acid).

Above and below, in those cases, where a chemical structure with a stereogenic center is shown and no specific stereochemistry is indicated, the structure includes all possible stereoisomers as well as mixtures thereof.

The different stereoisomers of a given compound are useful for the analytical characterization of a specific sample (e.g. for quality control pruposes) via NMR, HPLC, SFC or any other suitable analytical method. Thus, another aspect of the present invention relates to the use of stereoisomers of compounds according to the present invention in analytical characterization methods.

The term solvates of the compounds is taken to mean adductions of inert solvent molecules onto the compounds which form owing to their mutual attractive force. Solvates are, for example, alkoxides.

Similarly, the term hydrate of a compound is taken to mean addutions of one or more water molecules onto the compounds which form owning to their mutual attractive force.

It is understood that the invention also relates to the solvates or hydrates of a salt.

The expression "effective amount” denotes the amount of a medicament or of a pharmaceutical active ingredient which causes in a tissue, system, animal or human a biological or medical response which is sought or desired, for example, by a researcher or physician.

In addition, the expression "therapeutically effective amount” denotes an amount which, compared with a corresponding subject who has not received this amount, has the following consequence: improved treatment, healing, prevention or elimination of a disease, syndrome, condition, complaint, disorder or side-effects or also the reduction in the advance of a disease, complaint or disorder. The expression "therapeutically effective amount” also encompasses the amounts which are effective for increasing normal physiological function. The invention also relates to the use of mixtures of the compounds according to any of formulae (I-a), (I-b), (I-c) or (1-d), for example mixtures of two diastereomers, for example in the ratio 1 : 1, 1 :2, 1 :3, 1 :4, 1 :5, 1 : 10, 1 : 100 or 1 : 1000.

In general, the synthesis pathways for any individual compounds of formulae (I-a), (I-b), (I-c) and (l-d)will depend on the specific substitutents of each molecule and upon the ready availability of Intermediates necessary; again, such factors being appreciated by those of ordinary skill in the art. For all the protection and de-protection methods, see Philip J. Kocienski, in “Protecting Groups”, Georg Thieme Verlag Stuttgart, New York, 1994 and, Theodora W. Greene and Peter G. M. Wuts in “Protective Groups in Organic Synthesis”, Wiley Interscience, 3rd Edition 1999.

Compounds of this invention can be isolated in association with solvent molecules by crystallization from evaporation of an appropriate solvent.

Isotopes

There is furthermore intended that a compound of the formula (I-a), (I-b), (I-c) or (1-d) includes isotope-labelled forms thereof. An isotope-labelled form of a compound of the formula (I-a), (I-b), (I-c) or (1-d) is identical to this compound apart from the fact that one or more atoms of the compound have been replaced by an atom or atoms having an atomic mass or mass number which differs from the atomic mass or mass number of the atom which usually occurs naturally. Examples of isotopes which are readily commercially available and which can be incorporated into a compound of the formula (I-a), (I-b), (I-c) or (1-d) by well-known methods include isotopes of hydrogen, carbon, nitrogen, oxygen, phos-phorus, fluorine and chlorine, for example ²H, ³H, ¹³C, ¹⁴C, ¹⁵N, ¹⁸O, ¹⁷0, ³¹P, ³²P, ³⁵S, ¹⁸F and ³⁶CI, respectively. A compound of the formula (I-a), (I-b), (I-c) or (1-d), or a pharmaceutically acceptable salt thereof which contains one or more of the above- mentioned isotopes and/or other isotopes of other atoms is intended to be part of the present invention. An isotope-labelled compound of the formula (I-a), (I-b), (I-c) or (1-d) can be used in a number of beneficial ways. For example, an isotope-labelled compound of the formula (I-a), (I-b), (I-c) or (1-d) into which, for example, a radioisotope, such as ³H or ¹⁴C, has been incorporated is suitable for medicament and/or substrate tissue distribution assays. These radioisotopes, i.e. tritium (³H) and carbon-14 (¹⁴C), are particularly preferred owing to simple preparation and excellent detectability. Incorporation of heavier isotopes, for example deuterium (²H), into a compound of the formula (I-a), (I-b), (I-c) or (1 -d) may have therapeutic advantages owing to the higher metabolic stability of this isotope-labelled compound. Higher metabolic stability translates directly into an increased in vivo half-life or lower dosages, which under most circumstances would represent a preferred embodi-ment of the present invention. An isotope-labelled compound of the formula (I-a), (I-b), (I-c) or (1-d) can usually be prepared by carrying out the procedures dis-closed in the synthesis schemes and the related description, in the example part and in the preparation part in the present text, replacing a non-isotope-labelled reactant by a readily available isotope-labelled reactant.

Deuterium (²H) can also be incorporated into a compound of the formula (I-a), (I-b), (I-c) or (1-d) for the purpose of manipulating the oxidative metabolism of the compound by way of the primary kinetic isotope effect. The primary kinetic isotope effect is a change of the rate for a chemical reaction that results from exchange of isotopic nuclei, which in turn is caused by the change in ground state energies necessary for covalent bond formation after this isotopic exchange. Exchange of a heavier isotope usually results in a lowering of the ground state energy for a chemical bond and thus cause a reduction in the rate in ratelimiting bond breakage. If the bond breakage occurs in or in the vicinity of a saddle-point region along the coordinate of a multi-product reaction, the product distribution ratios can be altered substantially. For explanation: if deuterium is bonded to a carbon atom at a nonexchangeable position, rate differences of kNi/ko = 2-7 are typical. If this rate difference is successfully applied to a compound of the formula (I-a), (I-b), (I-c) or (1-d) that is susceptible to oxidation, the profile of this compound in vivo can be drastically modified and result in improved pharmacokinetic properties.

The present invention relates to a pharmaceutical formulation (preferably for use in the treatment of an immunoregulatory abnormality or a cancer) comprising at least one compound of formula (I-a), (I-b), (I-c) or (1-d) (particularly a therapeutically effective amount of a compound of formula (I-a), (I-b), (I-c) or (1-d)), and/or a solvate, oligomer, adduct or stereoisomer thereof as well as a pharmaceutically acceptable salt of each of the foregoing, including mixtures thereof in all ratios, as active ingredient, together with a pharmaceutically acceptable carrier.

For the purpose of the present invention the term “pharmaceutical formulation” refers to a composition or product comprising one or more active ingredients, and one or more inert ingredients that make up the carrier, as well as any product which results, directly or indirectly, from combination, complexation or aggregation of any two or more of the ingredients, or from dissociation of one or more of the ingredients, or from other types of reactions or interactions of one or more of the ingredients. Accordingly, the pharmaceutical formulations of the present invention encompass any composition made by admixing at least one compound of the present invention and a pharmaceutically acceptable carrier, excipient or vehicle.

The pharmaceutical formulations of the present invention also encompass any composition that further comprises a second active ingredient and/or a solvate thereof as well as a pharmaceutically acceptable salt of the foregoing, including mixtures thereof in all ratios, wherein that second active ingredient is other than a compound of formula (I-a), (I-b), (I-c) or (1-d) wherein all residues are defined above.

The pharmaceutical formulations according to the present invention can be used as medicaments in human and veterinary medicine.

One embodiment of the present invention is a compound of any one of formulae (I-a), (I- b), (I-c), and (I-d), or a pharmaceutically acceptable salt thereof, for use to treat an LMP7- mediated disorder. In one aspect of this embodiment, the LMP7-mediated disorder is an immunoregulatory abnormality is preferably an autoimmune or chronic inflammatory disease selected from the group consisting of: systemic lupus erythematosis, chronic rheumatoid arthritis, inflammatory bowel disease, multiple sclerosis, amyotrophic lateral sclerosis (ALS), atherosclerosis, scleroderma, autoimmune hepatitis, Sjogren Syndrome, lupus nephritis, glomerulonephritis, Rheumatoid Arthritis, Psoriasis, Myasthenia Gravis, Imunoglobuline A nephropathy, Vasculitis, Transplant rejection, Myositis, Henoch- Schonlein Purpura and asthma; cancer is preferably a hematological malignancy or a solid tumor, wherein the hematological malignancy is preferably a disease selected from the group of malignant B- and T/NK-cell non-Hodgkin lymphoma such as: multiple myeloma, mantle cell lymphoma, diffuse large B-cell lymphoma, plasmocytoma, follicular lymphoma, immunocytoma, acute lymphoblastic leukemia, chronic lymphocytic leukemia and myeloid leukemia; and wherin the solid tumor is preferably a disease selected from the group of: inflammatory breast, liver and colon cancer, lung cancer, head and neck cancer, prostate cancer, pancreas cancer, bladder cancer, renal cancer, hepatocellular cancer and gastric cancer. In one aspect of this invention, the cancer is multiple myeloma.

In one embodiment, the LMP7-mediated disorder is cancer such as a B-cell proliferative disorder, e.g., diffuse large B cell lymphoma, follicular lymphoma, chronic lymphocytic lymphoma, chronic lymphocytic leukemia, acute lymphocytic leukemia, B-cell pro lymphocytic leukemia, lymphoplasmacytic lymphoma/Waldenstrom macroglobulinemia, splenic marginal zone lymphoma, multiple myeloma (also known as plasma cell myeloma), non-Hodgkin's lymphoma, Hodgkin's lymphoma, plasmacytoma, extranodal marginal zone B cell lymphoma, nodal marginal zone B cell lymphoma, mantle cell lymphoma, mediastinal (thymic) large B cell lymphoma, intravascular large B cell lymphoma, primary effusion lymphoma, Burkitt lymphoma/leukemia, or lymphomatoid granulomatosis. In some embodiments, the cancer is breast cancer, prostate cancer, or cancer of the mast cells (e.g., mastocytoma, mast cell leukemia, mast cell sarcoma, systemic mastocytosis). In one embodiment, the cancer is bone cancer. In another embodiment, the cancer is of other primary origin and metastasizes to the bone. In certain embodiments, the cancer is colorectal cancer or pancreatic cancer. In certain embodiments, the cancer is cancer is melanoma, glioma, glioblastomas, or cancer of the breast, lung, bladder, esophagus, stomach, colon, head, neck, ovary, prostate, pancreas, rectum, endometrium, or liver. In other embodiments, the cancer is triple-negative breast cancer, non-small cell lung cancer, and head and neck carcinoma. In certain embodiments, the cancer is multiple myeloma. In one aspect of this embodiment, the subject with multiple myeloma has a t(4; 14) and/or t( 14; 16) translocation.

In certain embodiments, the cancer is hematological malignancy selected from mantle cell lymphoma (MCL), T cell leukemia/lymphoma, acute myeloid leukemia (AML), acute lymphoblastic leukemia (ALL), diffuse large B-cell lymphoma (DLBCL), chronic lymphocytic leukemia (CLL), chronic myelogenous leukemia (CML), follicular lymphoma (FL) or marginal zone B-cell lymphoma (MZL).

In certain embodiments, the LMP7-mediated disorder is monoclonal gammopathy of uncertain significance (MGUS); smoldering multiple myeloma (SMM); and/or solitary plasmacytoma.

Dosage/ Administration

Pharmaceutical formulations can be administered in the form of dosage units, which comprise a predetermined amount of active ingredient per dosage unit. Such a unit can comprise, for example, 0.5 mg to 1 g, preferably 1 mg to 700 mg, particularly preferably 5 mg to 100 mg, of a compound according to the invention, depending on the disease condition treated, the method of administration and the age, weight and condition of the patient, or pharmaceutical formulations can be administered in the form of dosage units which comprise a predetermined amount of active ingredient per dosage unit. Preferred dosage unit formulations are those which comprise a daily dose or part-dose, as indicated above, or a corresponding fraction thereof of an active ingredient. Furthermore, pharmaceutical formulations of this type can be prepared using a process, which is generally known in the pharmaceutical art.

Pharmaceutical formulations can be adapted for administration via any desired suitable method, for example by oral (including buccal or sublingual), rectal, nasal, topical (including buccal, sublingual or transdermal), vaginal or parenteral (including subcutaneous, intramuscular, intravenous or intradermal) methods. Such formulations can be prepared using all processes known in the pharmaceutical art by, for example, combining the active ingredient with the excipient(s) or adjuvant(s). Pharmaceutical formulations adapted for oral administration can be administered as separate units, such as, for exaple, capsules or tablets; powders or granules; solutions or suspensions in aqueous or non-aqueous liquids; edible foams or foam foods; or oil-in-water liquid emulsions or water-in-oil liquid emulsions.

Thus, for example, in the case of oral administration in the form of a tablet or capsule, the active-ingredient component can be combined with an oral, non-toxic and pharmaceutically acceptable inert excipient, such as, for example, ethanol, glycerol, water and the like. Powders are prepared by comminuting the compound to a suitable fine size and mixing it with a pharmaceutical excipient comminuted in a similar manner, such as, for example, an edible carbohydrate, such as, for example, starch or mannitol. A flavour, preservative, dispersant and dye may likewise be present.

Capsules are produced by preparing a powder mixture as described above and filling shaped gelatine shells therewith. Glidants and lubricants, such as, for example, highly disperse silicic acid, talc, magnesium stearate, calcium stearate or polyethylene glycol in solid form, can be added to the powder mixture before the filling operation. A disintegrant or solubiliser, such as, for example, agar-agar, calcium carbonate or sodium carbonate, may likewise be added in order to improve the availability of the medica-ment after the capsule has been taken.

In addition, if desired or necessary, suitable binders, lubricants and disintegrants as well as dyes can likewise be incorporated into the mixture. Suitable binders include starch, gelatine, natural sugars, such as, for example, glucose or beta-lactose, sweeteners made from maize, natural and synthetic rubber, such as, for example, acacia, tragacanth or sodium alginate, carboxymethylcellulose, polyethylene glycol, waxes, and the like. The lubricants used in these dosage forms include sodium oleate, sodium stearate, magnesium stearate, sodium benzoate, sodium acetate, sodium chloride and the like. The disintegrants include, without being restricted thereto, starch, methylcellulose, agar, bentonite, xanthan gum and the like. The tablets are formulated by, for example, preparing a powder mixture, granulating or drypressing the mixture, adding a lubricant and a disintegrant and pressing the entire mixture to give tablets. A powder mixture is prepared by mixing the compound comminuted in a suitable manner with a diluent or a base, as described above, and optionally with a binder, such as, for example, carboxymethylcellulose, an alginate, gelatine or polyvinyl-pyrrolidone, a dissolution retardant, such as, for example, paraffin, an absorption accelerator, such as, for example, a quaternary salt, and/or an absorbant, such as, for example, bentonite, kaolin or dicalcium phosphate. The powder mixture can be granulated by wetting it with a binder, such as, for example, syrup, starch paste, acadia mucilage or solutions of cellulose or polymer materials and pressing it through a sieve. As an alternative to granulation, the powder mixture can be run through a tableting machine, giving lumps of non-uniform shape which are broken up to form granules. The granules can be lubricated by addition of stearic acid, a stearate salt, talc or mineral oil in order to prevent sticking to the tablet casting moulds. The lubricated mixture is then pressed to give tablets. The active ingredients can also be combined with a free-flowing inert excipient and then pressed directly to give tablets without carrying out the granulation or dry-pressing steps. A transparent or opaque protective layer consisting of a shellac sealing layer, a layer of sugar or polymer material and a gloss layer of wax may be present. Dyes can be added to these coatings in order to be able to differentiate between different dosage units.

Oral liquids, such as, for example, solution, syrups and elixirs, can be prepared in the form of dosage units so that a given quantity comprises a pre-specified amount of the compounds. Syrups can be prepared by dissolving the compounds in an aqueous solution with a suitable flavour, while elixirs are prepared using a non-toxic alcoholic vehicle. Suspensions can be for-mulated by dispersion of the compounds in a non-toxic vehicle. Solubilisers and emulsifiers, such as, for example, ethoxylated isostearyl alcohols and polyoxyethylene sorbitol ethers, preservatives, flavour additives, such as, for example, peppermint oil or natural sweeteners or saccharin, or other artificial sweeteners and the like, can likewise be added.

The dosage unit formulations for oral administration can, if desired, be encapsulated in microcapsules. The formulation can also be prepared in such a way that the release is extended or retarded, such as, for example, by coating or embedding of particulate material in polymers, wax and the like. The compounds of the formula (I-a), (I-b), (I-c) or (1-d) and salts thereof and the other active ingredients can also be administered in the form of liposome delivery systems, such as, for exam-pie, small unilamellar vesicles, large unilamellar vesicles and multilamellar vesicles. Liposomes can be formed from various phospholipids, such as, for example, cholesterol, stearylamine or phosphatidylcholines.

Pharmaceutical formulations adapted for transdermal administration can be administered as independent plasters for extended, close contact with the epidermis of the recipient. Thus, for example, the active ingredient can be delivered from the plaster by iontophoresis, as described in general terms in Pharmaceutical Research, 3(6), 318 (1986).

Pharmaceutical compounds adapted for topical administration can be formulated as ointments, creams, suspensions, lotions, powders, solutions, pastes, gels, sprays, aerosols or oils.

For the treatment of the eye or other external tissue, for example mouth and skin, the formulations are preferably applied as topical ointment or cream. In the case of formulation to give an ointment, the active ingredient can be employed either with a paraffinic or a water-miscible cream base. Alternatively, the active ingredient can be formulated to give a cream with an oil-in-water cream base or a water-in-oil base.

Pharmaceutical formulations adapted for topical application to the eye include eye drops, in which the active ingredient is dissolved or sus-pended in a suitable carrier, in particular an aqueous solvent.

Pharmaceutical formulations adapted for topical application in the mouth encompass lozenges, pastilles and mouthwashes.

Pharmaceutical formulations adapted for rectal administration can be administered in the form of suppositories or enemas.

Pharmaceutical formulations adapted for nasal administration in which the carrier substance is a solid comprise a coarse powder having a particle size, for example, in the range 20-500 microns, which is administered in the manner in which snuff is taken, i.e. by rapid inhalation via the nasal passages from a container containing the powder held close to the nose. Suitable formulations for administration as nasal spray or nose drops with a liquid as carrier substance encompass active-ingredient solutions in water or oil.

Pharmaceutical formulations adapted for administration by inhalation encompass finely particulate dusts or mists, which can be generated by various types of pressurised dispensers with aerosols, nebulisers or insuf-flators.

Pharmaceutical formulations adapted for vaginal administration can be administered as pessaries, tampons, creams, gels, pastes, foams or spray formulations.

Pharmaceutical formulations adapted for parenteral administration include aqueous and non-aqueous sterile injection solutions comprising antioxidants, buffers, bacteriostatics and solutes, by means of which the formulation is rendered isotonic with the blood of the recipient to be treated; and aqueous and non-aqueous sterile suspensions, which may comprise suspension media and thickeners. The formulations can be administered in singledose or multidose containers, for example sealed ampoules and vials, and stored in freeze- dried (lyophilised) state, so that only the addition of the sterile carrier liquid, for example water for injection purposes, immediately before use is necessary.

Injection solutions and suspensions prepared in accordance with the recipe can be prepared from sterile powders, granules and tablets.

It goes without saying that, in addition to the above particularly mentioned constituents, the formulations may also comprise other agents usual in the art with respect to the particular type of formulation; thus, for example, formulations which are suitable for oral administration may comprise flavours.

The compositions/formulations according to the invention can be used as medicaments in human and veterinary medicine.

A therapeutically effective amount of a compound of the formula (I-a), (I-b), (I-c) or (1-d) and of the other active ingredient depends on a number of factors, including, for example, the age and weight of the animal, the precise disease condition which requires treatment, and its severity, the nature of the formulation and the method of administration, and is ultimately determined by the treating doctor or vet. However, an effective amount of a compound is generally in the range from 0.1 to 100 mg/kg of body weight of the recipient (mammal) per day and particularly typically in the range from 1 to 10 mg/kg of body weight per day. Thus, the actual amount per day for an adult mammal weighing 70 kg is usually between 70 and 700 mg, where this amount can be administered as an individual dose per day or usually in a series of part-doses (such as, for example, two, three, four, five or six) per day, so that the total daily dose is the same. An effective amount of a salt or solvate or of a physiologically functional derivative thereof can be determined as the fraction of the effective amount of the compound per se.

The invention further relates to a compound according to formula (I-a), (I-b), (I-c) or (1-d) or any specific embodiment described above and/or its solvates, or stereoisomers thereof as well as the pharmaceutically acceptable salts of each of the foregoing, including mixtures thereof in all ratios, for use in the prevention and/or treatment of medical conditions that are affected by inhibiting LMP7.

The invention relates to a compound according to formula (I-a), (I-b), (I-c) or (1-d), or any specific embodiment described above, and/or a solvate, oligomers, adducts or stereoisomers thereof, as well as the pharmaceutically acceptable salts of each of the foregoing, including mixtures thereof in all ratios, for use in the treatment of a LMP7-mediated disorder. In one aspect of this embodiment, the LMP7-mediated disorder is an immunoregulatory abnomality or cancer (including in particular hematological malignanciey and solid tumors).

The present invention furthermore relates to a method of treating a subject suffering from an immunerogulatory abnomality or a cancer, comprising administering to said subject a compounds of formula (I-a), (I-b), (I-c) or (1-d) in an amount that is effective for treating said immunoregulatory abnormality or a cancer. The present invention preferably relates to a method of treating a subject suffering from an autoimmune or chronic inflammatory disease, a hematological malignancy or a solid tumor.

The disclosed compounds of the formula (I-a), (I-b), (I-c) or (1-d) can be administered and/or used in combination with other known therapeutic agents (active ingredients), including anticancer agents. As used herein, the term "anticancer agent" relates to any agent which is administered to a patient with cancer for the purposes of treating the cancer.

The anti-cancer treatment defined above may be applied as a monotherapy or may involve, in addition to the herein disclosed compounds of formula (I-a), (I-b), (I-c) or (1-d), conventional surgery or radiotherapy or medicinal therapy. Such medicinal therapy, e.g. a chemotherapy or a targeted therapy, may include one or more, but preferably one, of the following anti-tumor agents:

Alkylating agents such as altretamine, bendamustine, busulfan, carmustine, chlorambucil, chlormethine, cyclophosphamide, dacarbazine, ifosfamide, improsulfan, tosilate, lomustine, melphalan, mitobronitol, mitolactol, nimustine, ranimustine, temozolomide, thiotepa, treosulfan, mechloretamine, carboquone; apaziquone, fotemustine, glufosfamide, palifosfamide, pipobroman, trofosfamide, uramustine, TH-302⁴, VAL-083⁴;

Platinum Compounds such as carboplatin, cisplatin, eptaplatin, miriplatine hydrate, oxaliplatin, lobaplatin, nedaplatin, picoplatin, satraplatin;

DNA altering agents such as amrubicin, bisantrene, decitabine, mitoxantrone, procarbazine, trabectedin, clofarabine; amsacrine, brostallicin, pixantrone, laromustine¹’³;

Topoisomerase Inhibitors such as etoposide, irinotecan, razoxane, sobuzoxane, teniposide, topotecan; amonafide, belotecan, elliptinium acetate, voreloxin;

Microtubule modifiers such as cabazitaxel, docetaxel, eribulin, ixabepilone, paclitaxel, vinblastine, vincristine, vinorelbine, vindesine, vinflunine; fosbretabulin, tesetaxel;

Antimetabolites such as asparaginase³, azacitidine, calcium levofolinate, capecitabine, cladribine, cytarabine, enocitabine, floxuridine, fludarabine, fluorouracil, gemcitabine, mercaptopurine, methotrexate, nelarabine, pemetrexed, pralatrexate, azathioprine, thioguanine, carmofur; doxifluridine, elacytarabine, raltitrexed, sapacitabine, tegafur^2,3, trimetrexate;

Anticancer antibiotics such as bleomycin, dactinomycin, doxorubicin, epirubicin, idarubicin, levamisole, miltefosine, mitomycin C, romidepsin, streptozocin, valrubicin, zinostatin, zorubicin, daunurobicin, plicamycin; aclarubicin, peplomycin, pirarubicin;

Hormones/ Antagonists such as abarelix, abiraterone, bicalutamide, buserelin, calusterone, chlorotrianisene, degarelix, dexamethasone, estradiol, fluocortolone, fluoxymesterone, flutamide, fulvestrant, goserelin, histrelin, leuprorelin, megestrol, mitotane, nafarelin, nandrolone, nilutamide, octreotide, prednisolone, raloxifene, tamoxifen, thyrotropin alfa, toremifene, trilostane, triptorelin, diethylstilbestrol; acolbifene, danazol, deslorelin, epitiostanol, orteronel, enzalutamide^1,3;

Aromatase inhibitors such as aminoglutethimide, anastrozole, exemestane, fadrozole, letrozole, testolactone; formestane;

Small molecule kinase inhibitors such as crizotinib, dasatinib, erlotinib, imatinib, lapatinib, nilotinib, pazopanib, regorafenib, ruxolitinib, sorafenib, sunitinib, vandetanib, vemurafenib, bosutinib, gefitinib, axitinib; afatinib, alisertib, dabrafenib, dacomitinib, dinaciclib, dovitinib, enzastaurin, nintedanib, lenvatinib, linifanib, linsitinib, masitinib, midostaurin, motesanib, neratinib, orantinib, perifosine, ponatinib, radotinib, rigosertib, tipifarnib, tivantinib, tivozanib, trametinib, pimasertib, brivanib alaninate, cediranib, apatinib⁴, cabozantinib S-malate^1,3, ibrutinib^1,3, icotinib⁴, buparlisib², cipatinib⁴, cobimetinib^1,3, idelalisib¹’³, fedratinib¹, XL-647⁴;

Photosensitizers such as methoxsalen³; porfimer sodium, talaporfin, temoporfin;

Antibodies such as alemtuzumab, besilesomab, brentuximab vedotin, cetuximab, denosumab, ipilimumab, ofatumumab, panitumumab, rituximab, tositumomab, trastuzumab, bevacizumab, pertuzumab^2,3; catumaxomab, elotuzumab, epratuzumab, farletuzumab, mogamulizumab, necitumumab, nimotuzumab, obinutuzumab, ocaratuzumab, oregovomab, ramucirumab, rilotumumab, siltuximab, tocilizumab, zalutumumab, zanolimumab, matuzumab, dalotuzumab^1,2’³, onartuzumab^1,3, racotumomab¹, tabalumab¹’³, EMD-525797⁴, nivolumab^1,3;

Cytokines such as aldesleukin, interferon alfa², interferon alfa2a³, interferon alfa2b^2,3; celmoleukin, tasonermin, teceleukin, oprelvekin^1,3, recombinant interferon beta- la⁴;

Drug Conjugates such as denileukin diftitox, ibritumomab tiuxetan, iobenguane 1123, prednimustine, trastuzumab emtansine, estramustine, gemtuzumab, ozogamicin, aflibercept; cintredekin besudotox, edotreotide, inotuzumab ozogamicin, naptumomab estafenatox, oportuzumab monatox, technetium (99mTc) arcitumomab¹’³, vintafolide^1,3;

Vaccines such as sipuleucel³; vitespen³, emepepimut-S³, oncoVAX⁴, rindopepimut³, troVax⁴, MGN- 1601⁴, MGN-1703⁴;

Miscellaneous alitretinoin, bexarotene, bortezomib, everolimus, ibandronic acid, imiquimod, lenalidomide, lentinan, metirosine, mifamurtide, pamidronic acid, pegaspargase, pentostatin, sipuleucel³, sizofiran, tamibarotene, temsirolimus, thalidomide, tretinoin, vismodegib, zoledronic acid, vorinostat; celecoxib, cilengitide, entinostat, etanidazole, ganetespib, idronoxil, iniparib, ixazomib, lonidamine, nimorazole, panobinostat, peretinoin, plitidepsin, pomalidomide, procodazol, ridaforolimus, tasquinimod, telotristat, thymalfasin, tirapazamine, tosedostat, trabedersen, ubenimex, valspodar, gendicine⁴, picibanil⁴, reolysin⁴, retaspimycin hydrochloride¹’³, trebananib^2,3, virulizin⁴, carfilzomib¹’³, endostatin⁴, immucothel⁴, belinostat³, MGN-1703⁴;

⁴ Prop. INN (Proposed International Nonproprietary Name)

² Rec. INN (Recommended International Nonproprietary Names)

³USAN (United States Adopted Name)

⁴ no INN.

Included herein are methods of treatment in which at least one compound according to any one of formluae (I-a), (I-b), (I-c), or (I-d), or a pharmaceutically acceptable salt thereof, provided herein is administered in combination with one or more therapeutic agent. In one aspect of this embodiment, the one or more additional therapeutic agents is an EGFR pathway inhibitor, MAPK pathway inhibitor, XPO1 inhibitor, a DNA repair pathway inhibitor, FGFR pathway inhibitor, PI3K/AKT/mTOR pathway inhibitor, and/or MCL1 inhibitor.

Examples of the EGFR pathway inhibitor is selected from Erlotinib, Afatinib, Gefitinib, Cetuximab, Panitumumab, Lapatinib, Osimertinib, Trastuzumab, and/or Pertuzumab..

In some embodiments, the anti-inflammatory agent is a salicylate. Salicylates include by are not limited to acetylsalicylic acid or aspirin, sodium salicylate, and choline and magnesium salicylates. Examples of the MAPK pathway inhibitor is selected from Trametinib, Cobimetinib, Binimetinib, Selumetinib, Refametinib, Pimasertib, AMG 510, MRTX849, Vemurafenib, Dabrafemb, Encorafenib, LXH254, HM95573, XL281, RAF265, RAF709, LY3009120, Ulixertimb, SCH772984, TNO155, RMC-4630, JAB-3068, JAB-3312, AMG-510, MRTX849, LY3499446 and/or BI 1701963.

Examples of the XPO1 inhibitor is selected from Selinexor and/or KPT-8602.

Examples of the DNA repair pathway inhibitor is selected from M3541, M4076, BAY1895344, NOVI 401, E7016, BGB-290, CEP-9722, Olapanb, Rucapanb, Nirapanb, and/or Talazoparib.

Examples of the FGFR pathway inhibitor is selected from Erdafitinib, AZD4547, LY2874455, Debio 1347, NVP-BGJ398, Pemigatimb, Rogaratimb, PRN1371, TAS-120, and/or Nintedanib.

Examples of the PI3K/AKT/mTOR pathway inhibitor is selected from Rapamycin, Temsirolimus, Everolimus, Ridaforolimus, Alpelisib, Idelalisib, Copanlisib, Duvelisib, MK-2206, and/or AZD5363.

Examples of the MCL1 inhibitor is selected from A-1210477, VU661013, AZD5991, AMG-176, AMG-397, S63845, S64315, Venetoclax, HDM201, NVP-CGM097, RG-7112, MK-8242, RG-7388, SAR405838, AMG-232, DS-3032, RG7775, and/or APG-115.

The invention furthermore relates to the use of compounds of formula (I-a), (I-b), (I-c) or (1-d), and related formulae in combination with at least one further medicament active ingredient, preferably medicaments used in the treatment of multiple sclerosis such as cladribine or another co-agent, such as interferon, e.g. pegylated or non-pegylated interferons, preferably interferon beta and/or with compounds improving vascular function or in combination with immunomodulating agents for example Fingolimod; cyclosporins, rapamycins or ascomycins, or their immunosuppressive analogs, e.g. cyclosporin A, cyclosporin G, FK-506, ABT-281, ASM981, rapamycin, 40-O-(2-hydroxy)ethyl- rapamycin etc.; corticosteroids; cyclophosphamide; azathioprene; methotrexate; leflunomide; mizoribine; mycophenolic add; mycophenolate mofetil; 15-deoxyspergualine; diflucortolone valerate; difluprednate; Alclometasone dipropionate; amcinonide; amsacrine; asparaginase; azathioprine; basiliximab; beclometasone dipropionate; betamethasone; betamethasone acetate; betamethasone dipropionate; betamethasone phosphate sodique; betamethasone valerate; budesonide; captopril; chlormethine chlorhydrate; cladribine; clobetasol propionate; cortisone acetate; cortivazol; cyclophosphamide; cytarabine; daclizumab; dactinomycine; desonide; desoximetasone; dexamethasone; dexamethasone acetate; dexamethasone isonicotinate; dexamethasone metasulfobenzoate sodique; dexamethasone phosphate; dexamethasone tebutate;dichlorisone acetate; doxorubicine chlorhydrate; epirubicine chlorhydrate; fluclorolone acetonide; fludrocortisone acetate; fludroxycortide; flumetasone pivalate; flunisolide; fluocinolone acetonide; fluocinonide; fluocortolone; fluocortolone hexanoate; fluocortolone pivalate; fluoromethoIone; fluprednidene acetate; fluticasone propionate; gemcitabine chlorhydrate; halcinonide; hydrocortisone, hydrocortisone acetate, hydrocortisone butyrate, hydrocortisone hemisuccinate; melphalan; meprednisone; mercaptopurine; methylprednisolone; methylprednisolone acetate; methylprednisolone hemisuccinate; misoprostol; muromonab-cd3; mycophenolate mofetil; paramethasone acetate; prednazoline, prednisolone; prednisolone acetate; prednisolone caproate; prednisolone metasulfobenzoate sodique; prednisolone phosphate sodique; prednisone; prednylidene; rifampicine; rifampicine sodique; tacrolimus; teriflunomide; thalidomide; thiotepa; tixocortol pivalate; triamcinolone; triamcinolone acetonide hemisuccinate; triamcinolone benetonide; triamcinolone diacetate; triamcinolone hexacetonide; immunosuppressive monoclonal antibodies, e.g., monoclonal antibodies to leukocyte receptors, e g., MHC, CD2, CD3, CD4, CD7, CD25, CD28, B7, CD40, CD45 or CD58 or their ligands; or other immunomodulatory compounds, e.g. CTLA41g, or other adhesion molecule inhibitors, e.g. mAbs or low molecular weight inhibitors including Selectin antagonists and VLA-4 antagonists. A preferred composition is with Cyclosporin A, FK506, rapamycin or 40-(2-hydroxy)ethyl-rapamycin and Fingolimod.. These further medicaments, such as interferon beta, may be administered concomitantly or sequentially, e.g. by subcutaneous, intramuscular or oral routes. The invention furthermore relates to the use of compounds of formula (I-a), (I-b), (I-c) or (1-d), and related formulae in combination with at least one further medicament active ingredient, preferably medicaments used in the treatment of cancer (such as in particular the anticancer and/or antitumor agents described above).

The present invention further relates to a set (kit) consisting of separate packs of

(a) an effective amount of a compound of the formula (I-a), (I-b), (I-c) or (1-d) and /or a solvate, oligomer, adduct or stereoisomer thereof as well as a pharmaceutically acceptable salt of each of the foregoing, including mixtures thereof in all ratios, and

(b) an effective amount of a further medicament active ingredient.

The compounds of the present invention can be prepared according to the procedures of the following Schemes and Examples, using appropriate materials, and are further exemplified by the following specific examples.

Moreover, by utilizing the procedures described herein, in conjunction with ordinary skills in the art, additional compounds of the present invention claimed herein can be readily prepared. The compounds illustrated in the examples are not, however, to be construed as forming the only genus that is considered as the invention. The examples further illustrate details for the preparation of the compounds of the present invention. Those skilled in the art will readily understand that known variations of the conditions and processes of the following preparative procedures can be used to prepare these compounds.

The starting materials for the preparation of compounds of the present invention can prepared by methods as described in the examples or by methods known per se, as described in the literature of synthetic organic chemistry and known to the skilled artisan, or can be obtained commercially.

The invention further comprises a process for the preparation of compounds of the formula (I-a), (I-b), (I-c) or (1-d) as described above and pharmaceutically acceptable salts, tautomers and stereoisomers thereof, characterized by the following scheme:

The preparation consists of reacting a free boronic acid of formula (II), wherein W is [(lS,2R,4R)-7-oxabicylco[2.2.1]hepatan-2-yl, LY is CH2 and Y is benzofuranyl or chlorobenzofuranyl, with a second component (III) capable of forming an adduct with the boronic acid. Component III contains 2 donor groups (OH, COOH) being separated by a C2/C3 chain linker, which may carry further substituents R. The linker may be purely aliphatic, partly unsaturated or may a be part of an aromatic moiety.

The second component also may contain 3 donor groups as shown in III- 1. In this case bicyclic adducts are formed.

Examples of preparation applying component III or III-l are shown in the following schemes:

In particular the second component (III or III-l) capable of forming an adduct with the boronic acid is selected from alpha-hydroxy carboxylic acids, beta-hydroxy acids, 1,2- dioles, 1,3-dioles, 2-hydroxy ethylaminoacetic acids, diethanolamines, iminodiacetic acids, or pyridoxines.

The reaction is performed using conditions and methods well known to those skilled in the art by stirring a mixture of (II) and (III, III- 1 ) in a suitable solvent such as EE, DCM, MeOH, ACN, THF, TBME, DMSO, NMP, DMF, or mixtures of these solvents at a temperature between -20°C to 80°C, preferably at 50°C, for a few hours, e.g. one hour to 24 h.

The mixture is than cooled to room temperature or to below 10°C, until the adduct begins to precipitate. Alternatively, the solvent is slowly evaporated until the adduct begins to precipitate.

Another option to obtain crystalline material is to treat the reaction mixture with an antisolvent (e.g. TBME, heptane) and stir at a temperature between -20°C to 80°C, preferably at 40°C, for several hours, e.g. one hour to 24 h.

Another option to obtain crystalline material is to evaporate the initially used solvent completely and to recrystallize the remaining adduct using a different solvent than before. For recrystallisation solvents like EE, TBME, heptane, Acetonitrile or mixtures of these may be used.

The synthesis of compounds of formula (II) are described in WO 2019/038250.

Compounds of formula III are commercially available. Examples are pinacol, glycolic acid, (+)lactic acid, (-)lactic acid, pyridoxine. Examples of of compounds of formula III- 1 are 2-hydroxyethylaminoacetic acid, diethanol amine, and iminodiacetic acid. Examples

HPLC: Method A:

HPLC EliteLa Chrom 70173815;Waters XB ridge C83.5pm 4.6x50mm - 8.1 min; 2mL/min; 215nm; buffer A: 0.05% TFA/H2O; buffer B: 0.04% TFA/ACN; 0.0-0.2min 5% buffer B; 0.2-8. Imin 5%-100% buffer B; 8.1-10.0min 100%-5% buffer B.

Depending on the stability of the adduct under aqueous conditions in the HPLC mixtures of the free boronic acid and the adduct in various may be detected.

The invention will be illustrated, but not limited, by reference to the specific embodiments described in the following examples. Unless otherwise indicated in the schemes, the variables have the same meaning as described above.

Unless otherwise specified, all starting materials are obtained from commercial suppliers and used without further purifications. Unless otherwise specified, all temperatures are expressed in °C and all reactions are conducted at rt. Compounds were purified by either silica chromatography or preparative HPLC.

Unless stated otherwise all structures indicated below, where no specific stereochemistry is indicated, refer to mixtures of the stereoisomers.

Example 1: Synthesis of (lS,2R,4R)-N-((R)-2-(benzofuran-3-yl)-l-(4-oxo-l,3,2- dioxaborolan-2-yl)ethyl)-7-oxabicyclo[2.2.1]heptane-2-carboxamide

To a warm (~40°C) solution of glycolic acid (25.4 mg; 0.33 mmol) in 500 pL dry DCM containing a few 3 drops EE ((R)-2-(benzofuran-3-yl)-l-((lS,2R,4R)-7- oxabicyclo[2.2.1]heptane-2-carboxamido) ethyl)boronic acid (100 mg, 0.31 mmol) was added and stirred under argon atmosphere for 1.75h. The solvent was removed, and the residue was treated with 500pL TBME and stirred again at 40°C overnight. The obtained solid was filtered off, washed with TBME and dried in vacuo at 60°C for 3 days to afford 102 mg of (lS,2S,4R)-N-((R)-2-(benzofuran-3-yl)-l-(4-oxo-l,3,2-dioxaborolan-2- yl)ethyl)-7-oxabicyclo[2.2.1]heptane-2-carboxamide as white crystals (yield: 91%).

HPLC (method A): RT 3.77 mm (HPLC purity 100 %)

XRD: crystalline material (See Fig. 1)

'H NMR (700 MHz, Chloroform-d) d 7.58 (d, J = 7.6 Hz, 1H), 7.52 - 7.47 (m, 3H), 7.33 (t, J = 7.7 Hz, 1H), 7.29 - 7.26 (m, 1H), 4.70 - 4.65 (m, 1H), 4.64 - 4.53 (m, 1H), 4.39 - 4.32 (m, 1H), 4.28 - 4.21 (m, 1H), 3.18 - 3.10 (m, 1H), 3.07 - 3.00 (m, 1H), 2.87 - 2.82 (m, 1H), 2.84 - 2.74 (m, 1H), 1.97 (dd, J = 12.8, 9.2 Hz, 1H), 1.88 - 1.80 (m, 1H), 1.79 - 1.72 (m, 2H), 1.56 - 1.50 (m, 2H). Example 2: Synthesis of (lS,2R,4R)-N-((R)-2-(benzofuran-3-yl)-l-((R)-4-methyl-5- oxo-l,3,2-dioxaborolan-2-yl)ethyl)-7-oxabicyclo[2.2.1]heptane-2-carboxamide

To a solution of (R)-2-hydroxy-propionic acid (30.1 mm, 0.33 mmol) in 500pL dry DCM under argon atmosphere ((R)-2-(benzofuran-3-yl)-l-((lS,2R,4R)-7- oxabicyclo[2.2.1]heptane-2-carboxamido)ethyl)boronic acid (100 mg, 0.31 mmol) was added and stirred for 1.5h at RT. The solvent was removed, and the greasy residue was treated with 500pL TBME and stirred again at 40°C overnight. A crystalline precipitate was formed. The solid was filtered off, washed with TBME and dried in vacuo at 60°C for 3 days to give 89mg of (lS,2R,4R)-N-((R)-2-(benzofuran-3-yl)-l-((R)-4-methyl-5-oxo- l,3,2-dioxaborolan-2-yl)ethyl)-7-oxabicyclo[2.2.1]heptane-2-carboxamide as white solid (yield: 76%).

HPLC (method A): RT 3.77 min (HPLC purity 100 %)

XRD: crystalline material (See Fig. 2):

'H NMR (700 MHz, DMSO-d6) d 10.48 (s, IH), 7.72 - 7.60 (m, 2H), 7.53 (d, J = 8.1 Hz, IH), 7.33 - 7.28 (m, IH), 7.27 - 7.23 (m, IH), 4.73 - 4.61 (m, 2H), 4.22 - 4.01 (m, IH), 3.06 - 2.68 (m, 4H), 1.88 - 1.79 (m, 2H), 1.65 - 1.46 (m, 4H), 1.26 - 1.02 (m, 3H).

Example 3: Synthesis of (IS, 2R,4R)-N-((R)-2-(7-chlorobenzofuran-3-yl)-l-(4, 4,5,5- tetramethyl-l,3,2-dioxaborolan-2-yl)ethyl)-7-oxabicyclo[2.2.1]heptane-2- carboxamide

((R)-l-((lS,2R,4R)-7-oxabicyclo[2.2.1]heptane-2-carboxamido)-2-(7-chloro-benzofuran- 3-yl)ethyl)boronic acid (120 mg; 0.33 mmol) and pinacol (40 mg; 0.33 mmol) were dissolved in 1.2 mL EE using sonication and stirred under argon atmosphere at 50°C for Ih. The solution was diluted with ImL TBME (-> still clear solution) and the complete solvent was evaporated. The remaining foam was treated with 1 mL TBME and stirred over night at RT, leading to formation of a crystalline precipitate. The solid was filtered off, washed with TBME and dried in vacuo at 60°C for 3 days to afford 123 mg (1S,2R,4R)-N- ((R)-2-(7-chlorobenzofuran-3-yl)-l -(4,4,5, 5-tetramethyl- 1,3, 2-dioxaborolan-2-yl)ethyl)-7- oxabicyclo[2.2.1]heptane-2-carboxamide as white crystals (yield: 83.6%).

HPLC (method A): RT 5.50 min (HPLC purity 100 %)

XRD: crystalline material (See Fig. 3):

'H NMR (400 MHz, Chloroform-d) d 7.52 (s, 1H), 7.51 - 7.46 (m, 1H), 7.33 - 7.29 (m, 1H), 7.18 (t, J = 7.8 Hz, 1H), 6.95 - 6.89 (m, 1H), 4.62 - 4.54 (m, 2H), 3.01 - 2.94 (m, 1H), 2.91 - 2.85 (m, 1H), 2.81 - 2.72 (m, 2H), 1.88 (dd, J = 12.7, 9.1 Hz, 1H), 1.82 - 1.66 (m, 3H), 1.52 - 1.44 (m, 2H), 1.24 (s, 12H).

Example 4: Synthesis of (lS,2R,4R)-N-((R)-2-(benzofuran-3-yl)-l-(5- (hydroxymethyl)-8-methyl-4H-[l,3,2]dioxaborinino[4,5-c]pyridin-2-yl)ethyl)-7- oxabicyclo [2.2.1] heptane-2-carboxamide

To a solution of ((R)-2-(benzofuran-3-yl)-l-((lS,2R,4R)-7-oxabicyclo[2.2.1] heptane-2- carboxamido)ethyl)boronic acid (0.152 mmol; 50 mg) in 250 pL EE was added under stirring and argon atmosphere pyridoxine as free base (0.152 mmol; 25.7 mg), leading to a thick suspension, which dissolved after 20 minutes. The solution was stirred at 40°C for 5h, then the solvent was removed, and the residue was treated with 500 pL TBME and stirred again at 40°C over night. After 30 minutes a suspension was formed. The solid was filtered off, washed with TBME and dried in vacuo at 60°C for 3 days to afford 63.1 mg (lS,2R,4R)-N-((R)-2-(benzofuran-3-yl)-l-(5-(hydroxymethyl)-8-methyl-4H-[l,3,2]dioxa borinino [4,5-c]pyridin-2-yl)ethyl)-7-oxabicyclo[2.2. l]heptane-2-carboxamide as white crystals (yield: 81%).

HPLC (method A): RT 3.71 min

XRD: crystalline material (See Fig. 4):

'H NMR (400 MHz, Chloroform-d) d 7.90 (s, 1H), 7.62 - 7.58 (m, 1H), 7.51 - 7.46 (m, 2H), 7.37 - 7.32 (m, 1H), 7.34 - 7.29 (m, 1H), 7.28 - 7.23 (m, 1H), 4.96 (s, 2H), 4.69 - 4.65 (m, 2H), 4.60 (s, 2H), 3.09 - 3.00 (m, 2H), 2.92 - 2.80 (m, 2H), 2.45 (s, 3H), 1.96 (dd, J = 12.7, 9.1 Hz, 1H), 1.90 - 1.70 (m, 3H), 1.57 - 1.51 (m, 2H).

Example 5: Synthesis of (lS,2R,4R)-N-((R)-2-(7-chlorobenzofuran-3-yl)-l-

(tetrahydro-8Z⁴-|1.3.2|oxazaborolo|2.3-b|| 1.3.2|oxazaborol-8-yl)ethyl)-7- oxabicyclo [2.2.1] heptane-2-carboxamide

To a solution of [(lR)-2-(7-chlorobenzofuran-3-yl)-l-[[(lR,3R,4S)-7-oxabicyclo

[2.2.1]heptane-3-carbonyl]amino]ethyl]boronic acid (120 mg; 0.33 mmol) in 2.4 mL methanol was added a solution of diethanolamin (32 pL; 0.33 mmol) in 1.2 mL acetonitrile. After 2 min stirring, a precipitate was formed. After stirring for additional 3 hours, the solid was filtered off, washed with acetonitrile and dried in vacuo at 60°C to afford 116 mg (lS,2R,4R)-N-((R)-2-(7-chlorobenzofuran-3-yl)-l-(tetrahydro-8X⁴-

[1.3.2]oxazaborolo[2,3-b] [l,3,2]oxazaborol-8-yl)ethyl)-7-oxa bicyclo[2.2.1]heptane-2- carboxamide as white crystals (yield 81%).

HPLC (method A): RT 3.63 min

XRD: crystalline material (See Fig. 5):

'H NMR (400 MHz, Chloroform-d) d 7.51 - 7.50 (m, 1H), 7.51 (dd, J = 7.8, 1.1 Hz, 1H), 7.53 - 7.45 (m, 1H), 7.28 (dd, J = 7.8, 1.1 Hz, 1H), 7.15 (t, J = 7.8 Hz, 1H), 6.14 - 6.09 (m, 1H), 4.45 - 4.39 (m, 2H), 4.08 - 3.99 (m, 2H), 3.97 - 3.88 (m, 2H), 3.43 - 3.31 (m, 1H), 3.23 - 3.13 (m, 2H), 3.15 - 3.05 (m, 1H), 2.98 - 2.89 (m, 1H), 2.86 - 2.76 (m, 2H), 2.29 (dd, J = 9.0, 4.4 Hz, 1H), 1.69 - 1.62 (m, 3H), 1.39 - 1.34 (m, 2H), 1.34 - 1.26 (m, 1H).

Example 6: Synthesis of (IS, 2R,4R)-N-((R)-2-(benzofuran-3-yl)-l-(4, 4,5,5- tetramethyl-l,3,2-dioxaborolan-2-yl)ethyl)-7-oxabicyclo[2.2.1]heptane-2- carboxamide

((R)-2-(benzofuran-3-yl)-l-((lS,2R,4R)-7-oxabicyclo[2.2.1]heptane-2-carbox- amido)ethyl)boronic acid (100 mg; 0.30 mmol) and pinacol (47.6 mg; 0.39 mmol) were dissolved in 2 mL DCM and stirred under argon atmosphere at ~40°C for 2h. The solvent was evaporated and the solid was treated with 1 mL TBME and stirred at RT for 30 minutes. A crystalline precipitate was formed, which was filtered off, washed with TBME and dried in vacuo at 60°C for 3 days to afford 103 mg (lS,2R,4R)-N-((R)-2-(benzofuran-3-yl)-l- (4,4,5,5-tetramethyl-l,3,2-dioxaborolan-2-yl)ethyl)-7-oxabicyclo[2.2.1]heptane-2- carboxamide as white crystals (yield: 82.4%).

HPLC (method A): RT 5.080 min (HPLC purity 100 %)

XRD: crystalline material (See Fig. 6)

¹HNMR (700 MHz, Chloroform-d) d 7.61 - 7.59 (m, 1H), 7.49 - 7.47 (m, 1H), 7.45 - 7.44 (m, 1H), 7.32 - 7.29 (m, 1H), 7.26 - 7.23 (m, 1H), 6.97 - 6.93 (m, 1H), 4.59 - 4.56 (m, 2H), 3.00 - 2.96 (m, 1H), 2.91 - 2.88 (m, 1H), 2.79 - 2.74 (m, 2H), 1.89 - 1.85 (m, 1H), 1.79 - 1.74 (m, 1H), 1.73 - 1.66 (m, 2H), 1.50 - 1.45 (m, 2H), 1.27 - 1.24 (m, 12H). Example 7: Synthesis of ((lS,2R,4R)-N-((R)-2-(benzofuran-3-yl)-l-((S)-4-methyl-5- oxo-l,3,2-dioxaborolan-2-yl)ethyl)-7-oxabicyclo[2.2.1]heptane-2-carboxamide

To a solution of (S)-2-hydroxy-propionic acid (0.334 mmol; 30.1 mg) in 500pL dry DCM under argon atmosphere ((R)-2-(benzofuran-3-yl)-l-((lS,2R,4R)-7- oxabicyclo[2.2.1]heptane-2-carboxamido)ethyl)boronic acid (0.304 mmol; 100 mg) was added and stirred for 12h at RT.

The solvent was removed, and the greasy residue was treated with 500 pL TBME and stirred again at 40°C overnight. A crystalline precipitate was formed. The solid was filtered off, washed with TBME and dried in vacuo at 60°C for 3 days to give 91.4 mg of (1S,2R,4R)- N-((R)-2-(benzofuran-3-yl)-l-((S)-4-methyl-5-oxo-l,3,2-dioxaborolan-2-yl)ethyl)-7- oxabicyclo[2.2.1]heptane-2-carboxamideas white solid (yield: 78.5%).

HPLC (method A): RT 3.73 min (HPLC purity 100 %)

XRD: crystalline material (See Fig. 7):

'H NMR (700 MHz, Chloroform-d) d 7.57 (d, J = 7.6 Hz, 1H), 7.53 - 7.50 (m, 1H), 7.50 - 7.45 (m, 2H), 7.33 (t, J = 7.7 Hz, 1H), 7.28 - 7.26 (m, 1H), 4.68 - 4.65 (m, 1H), 4.62 - 4.56 (m, 1H), 4.46 - 4.33 (m, 1H), 3.14 - 3.10 (m, 1H), 3.05 - 2.98 (m, 1H), 2.88 - 2.76 (m, 2H), 1.99 - 1.94 (m, 1H), 1.86 - 1.80 (m, 1H), 1.79 - 1.72 (m, 2H), 1.56 - 1.53 (m, 2H), 1.52 - 1.36 (m, 3H).

Example 8: Synthesis of (lS,2R,4R)-N-((R)-2-(benzofuran-3-yl)-l-(2,6- dioxotetrahydro-8Z4-| 1.3.2|oxazaborolo|2.3-/j| | L3.2|oxazaborol-8-yl)ethyl)-7- oxabicyclo [2.2.1]heptane-2-carboxamide

A mixture of [(lR)-2-(benzofuran-3-yl)-l-[[(lR,3R,4S)-7-oxabicyclo [2.2. l]heptane-3- carbonyl]amino]ethyl]boronic acid (200 mg; 0.61 mmol) and iminodiacetic acid (80.7 mg, 0.61 mmol) in 1 ml DMSO and 100 pl acetonitrile was stirred at 80°C for 1 h. The hot solution was diluted with 8 ml acetonitrile and cooled under stirring in an ice bath. The formed precipitate was sucked off and lyophilized overnight. This material was suspended again in 4 ml boiling acetonitrile (10 min.), sucked off, washed with acetonitrile and dried for several days at 60°C to afford 162 mg (lS,2R,4R)-N-((R)-2-(benzofuran-3-yl)-l-(2,6- dioxotetrahydro-8X4-[l,3,2]oxazaborolo[2,3-/>][l,3,2]oxazaborol-8-yl)ethyl)-7-oxabicyclo [2.2.1]heptane-2-carboxamide as white crystals (yield 62.5%).

HPLC (method A): RT 4.52 min (depending on the HPLC conditions also free boronic acid may be formed)

XRD: crystalline material (See Fig. 8):

'H NMR (500 MHz, DMSO-d6) d 8.48 - 8.39 (m, 1H), 7.66 (s, 1H), 7.61 - 7.58 (m, 1H), 7.52 - 7.49 (m, 1H), 7.46 (d, J = 7.6 Hz, 1H), 7.30 - 7.26 (m, 1H), 7.23 (td, J = 7.4, 1.1 Hz, 1H), 4.45 - 4.42 (m, 1H), 4.29 - 4.26 (m, 1H), 4.12 - 3.98 (m, 2H), 3.84 - 3.78 (m, 2H), 3.26 - 3.19 (m, 1H), 2.87 (dd, J = 15.1, 11.6 Hz, 1H), 2.75 - 2.70 (m, 1H), 2.36 (dd, J = 8.9, 4.9 Hz, 1H), 1.77 - 1.71 (m, 1H), 1.51 (dd, J = 11.7, 9.0 Hz, 1H), 1.50 - 1.40 (m, 2H), 1.41 - 1.33 (m, 2H).

Example 9: Synthesis of (lS,2R,4R)-N-((lR)-2-(benzofuran-3-yl)-l-(2-oxotetrahydro-

8X4-[l,3,2]oxazaborolo[2,3-6][l,3,2]oxazaborol-8-yl)ethyl)-7- oxabicyclo [2.2.1] heptane-2-carboxamide

A mixture of [(lR)-2-(benzofuran-3-yl)-l-[[(lR,3R,4S)-7-oxabicyclo [2.2. l]heptane-3- carbonyl]amino]ethyl]boronic acid (200 mg; 0.61 mmol) and 2-[(2- hydroxyethyl)amino]acetic acid (72.4 mg, 0.61 mmol) in 1 ml DMSO and 100 pL acetonitrile was stirred at 80°C for 1 h. The hot solution was diluted with 8 mL acetonitrile and cooled under stirring in an ice bath. The formed precipitate was sucked off and lyophilized overnight. This material was suspended again in 5 mL acetonitrile at 60°C (10 min.), evaporated off, washed with acetonitrile and dried for several days at 60°C to afford 132 mg (lS,2R,4R)-N-((lR)-2-(benzofuran-3-yl)-l-(2-oxotetrahydro-8X4- [l,3,2]oxazaborolo[2,3-/>][l,3,2]oxazaborol-8-yl)ethyl)-7-oxabicyclo[2.2. l]heptane-2- carboxamide_as white crystals (yield 52.7%).

HPLC (method A): RT 4.12 min (depending on the HPLC conditions also free boronic acid may be formed)

XRD: crystalline material with peaks (See Fig. 9):

'H NMR (400 MHz, Chloroform-d) d 8.60 - 8.27 (m, 1H), 7.58 (t, J = 7.9 Hz, 1H), 7.49 - 7.44 (m, 2H), 7.32 - 7.26 (m, 1H), 7.25 - 7.20 (m, 1H), 6.29 - 6.18 (m, 1H), 4.40 - 4.28 (m, 2H), 4.12 - 3.82 (m, 3H), 3.45 - 3.12 (m, 4H), 3.04 - 2.87 (m, 2H), 2.30 - 2.23 (m, 1H), 1.70 - 1.56 (m, 3H), 1.38 - 1.29 (m, 2H), 1.28 - 1.04 (m, 1H).

Example 10: Characterization of Compounds 10-17

The following compounds were made using analogous procedures to those shown in Examples 1-9, above:

XRD: crystalline material with peaks

Compound 10: (See Fig. 10):

Compound 11: (See Fig. 11):

Compound 12: (See Fig. 12):

Compound 13: (See Fig. 13):

Compound 16: (See Fig. 14):

Example 11: Lyophilisation experiments from ACN / H2O mixtures:

In this Example, Compound 18 is examined. The structure of Compound 18 is:

The synthesis of Compound 18 is found in WO 19/38250 (Example 2, compound 9). The synthesis from the published application provides an amorphous material which is compared to the compounds of the present invention, below. A x-ray powder diffractograph of amorphous Compound 18 is provided in Figure 15. a) Lyophilisation from ACN : H2O 10 : 90 (v:v)

Approx. 64 mg neat, amorphous Compound 18 were dissolved in 90 mL of a mixture ACN : H2O 10 : 90 (v:v) at RT (approx. 22°C). The substance was completely dissolved. A filtration through a 0.45 pm syringe filter was carried out. This solution was flash- frozen in liquid nitrogen in a 100 mL round-bottom flask, and frozen sample attached to lyophilisator (Steris, Lyovac GT2) operating at approx. 0.8 mbar. After 3 days, a white solid residue was collected.

Water Vapour Sorption behaviour of amorphous Compound 18 reveals water uptake levels of approx. 2 % m/m in the relative humidity (rh) range 0-80 % rh. Compound 18 can be classified as hygroscopic acc. to Ph. Eur. Criteria (section 5. I L). Water Vapor Sorption isotherm (25°C) of Compound 18 is displayed in Figure 16. Water Vapour Sorption isotherm was acquired on a DVS-Advantage system from SMS.

Thermal behaviour of amorphous Compound 18 does not show significant thermal events prior decomposition at greater than 240°C. DSC profile is displayed in Figure 17. DSC scan of Comound 18 was acquired on a Mettler-Toledo DSC 1 with a heating rate of 5 K/min, using nitrogen purge gas at 50 mL/min. b) Additional Lyophilization conditions attempting to get crystallized Compound 18

1) Lyophilisation from ACN : H2O 30 : 70 (v:v)

Approximately 63 mg neat , amorphous Compound 18 was dissolved in 30 mL of a mixture ACN : H2O 30 : 70 (v:v) at RT (approx. 22°C). The substance was almost completely dissolved. To obtain a clear solution, filtration through a 0.45 pm syringe filter was carried out. This solution was flash-frozen in liquid nitrogen in a 100 mL roundbottom flask, and frozen sample attached to lyophilisator (Steris, Lyovac GT2) operating at approx. 0.8 mbar. After 3 days, a white solid residue was collected. The resulting powder was characterized using a x-ray powder diffractogram. The resulting spectra resembled Figure 15 (data not shown).

2) Lyophilisation from ACN : H2O 50 : 50 (v:v) Approximately 22 mg neat, amorphous Compound 18 was dissolved in 1 mL of a mixture ACN : H2O 50 : 50 (v:v) at RT (approx. 22°C). The substance was completely dissolved. A filtration through a 0.45 pm syringe filter was carried out. This solution was flash-frozen in liquid nitrogen in a 4 mL glass vial, and frozen sample attached to lyophilisator (Steris, Lyovac GT2) operating at approx. 0.8 mbar. After 3 days, a white solid residue was collected. The resulting powder was characterized using a x-ray powder diffractogram. The resulting spectra resembled Figure 15 (data not shown).

3) Lyophilisation from ACN : H2O 70 : 30 (v:v)

Approximately 24 mg neat, amorphous Compound 18 were dissolved in 1 mL of a mixture ACN : H2O 70 : 30 (v:v) at RT (approx. 22°C). The substance was completely dissolved. A filtration through a 0.45 pm syringe filter was carried out. This solution was flash-frozen in liquid nitrogen in a 4 mL glass vial, and frozen sample attached to lyophilisator (Steris, Lyovac GT2) operating at approx. 0.8 mbar. After 3 days, a white solid residue was collected. The resulting powder was characterized using a x-ray powder diffractogram. The XRPD spectra resembled Figure 15 (data not shown).

4) Lyophilization from ACN : H2O 90 : 10 (v:v)

Approximately 24 mg neat, amorphous Compound 18 was dissolved in 1 mL of a mixture ACN : H2O 90 : 10 (v:v) at RT (approx. 22°C). The substance was completely dissolved. A filtration through a 0.45 pm syringe filter was carried out. This solution was flash-frozen in liquid nitrogen in a 4 mL glass vial, and frozen sample attached to lyophilisator (Steris, Lyovac GT2) operating at approx. 0.8 mbar. After 3 days, a white solid residue was collected. The resulting powder was characterized using a x-ray powder diffractogram. The XRPD spectra resembled Figure 15 (data not shown).

Example 12: PK-Study

Female Han Wistar rats (n=3) received a single oral administration (1 mg/kg), by gavage as a suspension 0.25% Methylcellulose/0.25% Tween 20 in phosphate buffered saline. Consecutive blood samples were taken sub-lingually from n=3 animals, after 0.5, 1, 2, 4, 6 and 24 h and split into two aliquots. One aliquot was kept for the determination of concentrations of free boronic acid (Compound 18) in blood while the second aliquot was further processed to plasma. The animals were housed in individual metabolism cages allowing the collection of feces for a period of 24 h. The individual samples of feces were pooled before analysis. All samples were stored at -20±5°C until bioanalysis.

The concentrations of Compound 18 in blood and plasma were quantified using an UPLC method with tandem mass spectrometric detection (UPLC-MS/MS). The UPLC-MS system consisted of a Waters Acquity UPLC coupled to an AB Sciex mass spectrometer API 5500 Q-trap. The UPLC separation was carried out on a reversed phase column (Waters BEH Shield, 1.7 pM, 2.1 x 30 mm) using a mobile phase gradient with 0.1% formic acid and acetonitrile as eluents. The detection of Compound 18 was performed using multiple reaction monitoring in the positive ionization mode.

Plasma samples were spiked with internal standard in acetonitrile /water (60/40, v/v) containing 10% formic acid solution (22%) and then precipitated by addition of acetonitrile containing 0.1% formic acid. The organic phase was evaporated to dryness under a stream of nitrogen, and the residue was dissolved in acetonitrile/water (1:9, v/v) for LC-MS/MS analysis. A volume of 4 pL of each sample was injected into a UPLC- MS/MS system where linear calibration was achieved in blank rat plasma matrix from 8.00-5000 ng/mL.

Blood samples were precipitated by addition of acetonitrile containing 0.1% formic acid and the internal standard, mixed and centrifuged. An aliquot of the supernatant was diluted with an equal volume of Millipore water for LC-MS/MS analysis. A volume of 5 pL of each sample was injected into a UPLC-MS/MS system where linear calibration was achieved in blank rat blood matrix from 8.00-1000 ng/mL.

Feces samples were pooled, weighed and extracted with 4 times the volume (1:4, w/v) of ethanol/water (4: 1, v/v) containing 10% formic acid solution (22%). Aliquots of aqueous- ethanolic extracts (5 pL) were further diluted with acetonitrile/water (60:40, v/v) containing 10% formic acid solution (22%) (150 pL) and then spiked with internal standard solution for LC-MS/MS analysis. A volume of 4 pL of each sample was injected into a UPLC-MS/MS system where linear calibration was achieved in blank mouse feces matrix from 8.00-5000 ng/mL.

Pharmacokinetic parameters Cmax and tmax were taken from the observed data. Area under the curve (AUC) and all dose-normalized values were calculated using the custom- made software ‘DDS-TOX’. DDS-TOX’ values were evaluated for several compounds and shown comparable to the values given by the validated software WinNonLin. AUC values were calculated by non-compartmental analysis using the linear up/log down method. Numerical data for mean plasma concentrations and derived pharmacokinetic parameters were rounded to three significant digits for presentation. Oral bioavailability [F] is expressed as % of dose.

a) To a warm (~40°C) solution of citric acid 63.4 mg; 0.33 mmol) in 500 pL dry DCM containing a few 3 drops EE ((R)-2-(benzofuran-3-yl)-L((lS,2R,4R)-7- oxabicyclo[2.2.1]heptane-2-carboxamido) ethyl)boronic acid (100 mg, 0.31 mmol) was added and stirred under argon atmosphere for 1.75h. The solvent was removed, and the residue was treated with 500pL TBME and stirred again at 40°C overnight. No solid was obtained. When the solution was evaporated a white foam was obtained. This foam was dissolved in 200pM of EE. All attempts obtain crystals from the solution (e.g. storage in fridge, treatment with antisolvent) failed. b) To a warm (~70°C) suspension of citric acid 63.4 mg; 0.33 mmol) in 300 pL dry EE, a solution of ((R)-2-(benzofuran-3-yl)-l -((1 S,2R,4R)-7-oxabicyclo[2.2.1 ]heptane-2- carboxamido) ethyl)boronic acid (100 mg, 0.31 mmol) in 200 pL EE was added and stirred under argon atmosphere for 1.75h. The solvent was cooled to RT, treated with diethyl ether to get a sticky precipitate. All attempts to obtain crystals from this material failed.

Example 14: Preparation of formulations of compounds of the invention

Example A: Injection vials

A solution of 100 g of an active ingredient of formula (La), (Lb), (Lc) or (Ld) and 5 g of disodium hydrogenphosphate in 3 1 of bidistilled water is adjusted to pH 6.5 using 2 N hydrochloric acid, sterile filtered, transferred into injection vials, lyophilised under sterile conditions and sealed under sterile conditions. Each injection vial contains 5 mg of active ingredient. Example B: Suppositories

A mixture of 20 g of an active ingredient of the formula (La), (Lb), (Lc) or (Ld) with 100 g of soya lecithin and 1400 g of cocoa butter is melted, poured into molds and allowed to cool. Each suppository contains 20 mg of active ingredient.

Example C: Solution

A solution is prepared from 1 g of an active ingredient of the formula I, 9.38 g of NalLPCL 2 H2O, 28.48 g of Na2HPO4 • 12 H2O and 0.1 g of benzalkonium chloride in 940 mL of bidistilled water. The pH is adjusted to 6.8, and the solution is made up to 1 1 and sterilised by irradiation. This solution can be used in the form of eye drops.

Example D: Ointment

500 mg of an active ingredient of the formula (La), (Lb), (Lc) or (Ld) are mixed with 99.5 g of Vaseline under aseptic conditions.

Example E: Tablets

A mixture of 1 kg of active ingredient of the formula (La), (Lb), (Lc) or (Ld), 4 kg of lactose, 1.2 kg of potato starch, 0.2 kg of talc and 0.1 kg of magnesium stearate is pressed in a conventional manner to give tablets in such a way that each tablet contains 10 mg of active ingredient.

Example F: Dragees

Tablets are pressed analogously to Example E and subsequently coated in a conventional manner with a coating of sucrose, potato starch, talc, tragacanth and dye.

Example G: Capsules 2 kg of active ingredient of the formula (I-a), (I-b), (I-c) or (1-d) are introduced into hard gelatine capsules in a conventional manner in such a way that each capsule contains 20 mg of the active ingredient.

Example H: Ampoules

A solution of 1 kg of active ingredient of the formula (I-a), (I-b), (I-c) or (1-d) in 60 1 of bidistilled water is sterile filtered, transferred into ampoules, lyophilised under sterile conditions and sealed under sterile conditions. Each ampoule contains 10 mg of active ingredient.

Claims

1. A compound according to formula (I-a), (I-b), (I-c) or (1-d):

or a pharmaceutically acceptable salt thereof, wherein

R⁵ is absent, hydrogen, methyl or ethyl; and each of R⁶ and R⁷ independently selected from the group consisting of hydrogen, methyl, ethyl, isopropyl, -CF3, -CHF₂, -CH₂F, -CH₂OH, -CH2CH2OH, -OH, -F, and -Cl.

2. The compound, or a pharmaceutically acceptable salt thereof, accordingto claim 1, wherein Z is hydrogen.

3. The compound, or a pharmaceutically acceptable salt thereof, according to claim 1, wherein Z is -Cl.

4. The compound, or a pharmaceutically acceptable salt thereof, according to any one of formulae (I-a), (I-b) or (I-c) of claim 1, wherein each instance of R¹, R², R³ and R⁴ and R⁵ is independently either hydrogen or methyl.

5. The compound, or a pharmaceutically acceptable salt thereof, according to any one of formulae (I-a) or (I-b) of claim 1, wherein each instance of R¹, R², R³ and R⁴ is independently hydrogen, methyl, CH2OH, -CH2CH2OH or -OH.

6. The compound, or a pharmaceutically acceptable salt thereof, according to claim 5, wherein one of the residues R¹, R², R³ or R⁴ respresents CH2OH, -CH2CH2OH or -OH and the remaining residues are independently selected from hydrogen and methyl.

7. The compound, or a pharmaceutically acceptable salt thereof, according to formula (I- a) of claim 1, at least one instance of R¹ and R² and/or R³ and R⁴ are taken together with the carbon atom to which they are bound to form a carbonyl.

8. The compound, or a pharmaceutically acceptable salt thereof, according to formula (I- b) of claim 1, wherein R¹, R², R³ and R⁴ are all methyl.

9. The compound, or a pharmaceutically acceptable salt thereof, according to formula (I- c) of claim 1, wherein all R¹, R², R³ and R⁴ residues represent hydrogen.

10. The compound, or a pharmaceutically acceptable salt thereof, according to formula (I- c) of claim 1, wherein one instance of R¹ and R² are taken together to form a carbonyl group, the remaining residues R¹ and R² are independently either hydrogen or methyl, and one instance of R³ and R⁴ is methyl and the remaining residues R³ and R⁴ represent hydrogen.

11. A compound selected from the group consisting of:

or a pharmaceutically acceptable salt thereof. A crystalline form of a compound according to any one of claims 1-11. A pharmaceutical composition comprising a compound according to any one of claims 1-

12, or a pharmaceutically acceptable salt thereof, and a pharmaceutically acceptable carrier, vehicle or adjuvant. A method of treating an LMP7-mediated disease or disorder comprising administering an effective amount of a compound according to claim 1, or a pharmaceutically acceptable salt thereof, to a patient in need thereof. The method of claim 14, wherein the LMP7-mediated disease or disorder is an immunoregulatory abnormality or a cancer. The method of claim 15, the immunoregulatory abnormality is an autoimmune or chronic inflammatory disease selected from the group consisting of: systemic lupus erythematosis, chronic rheumatoid arthritis, inflammatory bowel disease, multiple sclerosis, amyotrophic lateral sclerosis (ALS), atherosclerosis, scleroderma, autoimmune hepatitis, Sjogren Syndrome, lupus nephritis, glomerulonephritis, Rheumatoid Arthritis, Psoriasis, Myasthenia Gravis, Imunoglobuline A nephropathy, Vasculitis, Transplant rejection, Myositis, Henoch-Schbnlein Purpura and asthma. The method of claim 15, wherein the LMP7-mediated disorder is a cancer. The method of claim 15, wherein the cancer is selected form a group consisting of: inflammatory breast and colon cancer, lung cancer, head and neck cancer, prostate cancer, pancreas cancer, bladder cancer, renal cancer, hepatocellular cancer and gastric cancer. The method of claim 15, wherein the cancer is a hematological malignancy. The method of claim 19, wherein the hematological malignancy is multiple myeloma, mantle cell lymphoma, diffuse large B-cell lymphoma, plasmocytoma, follicular lymphoma, immunocytoma, acute lymphoblastic leukemia, chronic lymphocytic leukemia and myeloid leukemia. The method of claim 19, wherein the hematological malignancy is selected from mantle cell lymphoma (MCL), T cell leukemia/lymphoma, acute myeloid leukemia (AML), acute lymphoblastic leukemia (ALL), diffuse large B-cell lymphoma (DLBCL), chronic lymphocytic leukemia (CLL), chronic myelogenous leukemia (CML), follicular lymphoma (FL) or marginal zone B-cell lymphoma (MZL).