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Example 13 WO2015104688

6-(6-aminopyridin-3-yl)-N-(2-morpholin-4-yl-1,3-benzothiazol-6-yl)pyridine-2-carboxamide

PROBABLE STRUCTURE

Example 1 ……..6′-amino-N-(2-morpholinooxazolo[4,5-b]pyridin-6-yl)-[2,3′-bipyridine]-6-carboxamideWO2015104688

Compound-6:  6′-amino-N-(5-(cyclopropyIamino)-2-morpholinobenzo [d]oxazoI-6-yl)-[2,3′-bipyridine]-6-carboxamide.WO2013042137

PROBABLE CA 4948, AU 4948,AU-4948, CA-4948

STRUCTURE AND SYNTHESIS COMING……..

Interleukin-1 Receptor Associated Kinase-4 (IRAK-4) is a serine/threonine protein kinase belonging to tyrosine like kinase (TLK) family. IRAK-4 is one of the important signalling components downstream of IL-1/Toll family of receptors (IL-1R, IL-18R, IL-33R, Toll-like receptors). Recent studies have reported occurrence of oncogenic mutations in MYD88 in 30% of ABC diffuse large B cell lymphomas (ABC DLBCL) and 90% of Waldenstrom’s macroglobulinemia (WM). Most of ABC DLBCLs have a single amino acid substitution of proline for the leucine at position 265 (L265P) in the TIR domain of MYD88 protein resulting in constitutive activation of IRAK-4. Thus, IRAK4 is an attractive therapeutic target for the treatment of B-cell lymphomas with activating MYD88 L265P mutation. We have designed, synthesized and tested small molecule IRAK-4 inhibitors based on hits originating from Aurigene’ s compound library. These novel compounds were profiled for IRAK4 kinase inhibition, anti-proliferative activity, kinase selectivity, and drug-like properties. Furthermore, selected compounds were tested in a proliferation assay and pIRAK1 mechanistic assay using ABC-DLBCL cell lines with activating MYD88 L265P mutation, OCI-lLy10 and OCI-lLy3. We have identified a series of novel bicyclic heterocycles as potent inhibitors of IRAK-4. Aurigene Lead compound exhibited potent inhibitory activity for IRAK-4 with an IC₅₀ of 3nM in biochemical assay. Aurigene Lead compound inhibited pIRAK1 levels, and proliferation of OCI-Ly3 and OCI-Ly10 cells with an IC₅₀1of 132nM and 52nM respectively. To the best of our knowledge, Aurigene Lead compound represents the most potent IRAK4 inhibitor reported for target modulation and anti-proliferative activity in DLBCL cell lines with activating MYD88 L265P mutation. Aurigene Lead compound has good oral pharmacokinetic profile in mice and has demonstrated excellent pharmacodynamic effect in an in vivo LPS induced TNF-α model with an ED₅₀ of 3.8 mg/Kg in mice. Preliminary in vitro tox studies indicated clean safety profile. Demonstration of efficacy in OCI-lLy10 mouse tumor model is ongoing. In summary, a series of potent IRAK-4 inhibitors belonging to 3 different chemical series have been discovered and are being evaluated for treatment of B-cell lymphomas.

Curis with the option to exclusively license Aurigene’s orally-available small molecule inhibitor of Interleukin-1 receptor-associated kinase 4 (IRAK4) in the precision oncology field. Curis expects to exercise its option to obtain exclusive licenses to both programs and file IND applications for a development candidate from each in 2015.

Recent studies have also shown that alterations of the MYD88 gene lead to dysregulation of its downstream target IRAK4 in a number of hematologic malignancies, including Waldenström’s Macroglobulinemia and a subset of diffuse large B-cell lymphomas, making IRAK4 an attractive target for the treatment of these cancers.

Small Molecule IRAK4 Kinase Inhibitor)

Innate immune responses mediated through Toll-like receptors or certain interleukin receptors are important mediators of the body’s initial defense against foreign antigens, while their dysregulation is associated with certain inflammatory conditions.  Toll-like receptor and interleukin receptor signaling through the adaptor protein MYD88, results in the assembly and activation of IRAK4, initiating a signaling cascade that induces cytokine and survival factor expression mediated by the transcription factor NFκB. More recently, components of this pathway are recognized to be genetically altered and have important roles in specific human cancers.  Toll-like receptor and interleukin receptor signaling through the adaptor protein MYD88, results in the assembly and activation of IRAK4, initiating a signaling cascade that induces cytokine and survival factor expression mediated by the transcription factor NFκB.  MYD88 gene mutations are shown to occur in approximately 30% of Activated B-Cell (ABC) subtype of diffuse large B-cell lymphomas (DLBCL)^1,2 and in over 90% of the B-cell malignancy Waldenstrom’s macroglobulinemia.³  Due to IRAK4’s central role in these signaling pathways, it is considered an attractive target for generation of therapeutics to treat these B-cell malignancies as well as certain inflammatory diseases.

As part of the collaboration with Aurigene, in October 2015 we exercised our option to exclusively license a program of orally-available, small molecule inhibitors of IRAK4 kinase, including the development candidate, CA-4948.  Curis expects to file an IND and initiate clinical testing of CA-4948 in patients with advanced hematologic cancers during the second half of 2016.

¹Nature. 2011; 470(7332):115–119²Immunology and Cell Biology. 2011; 89(6):659–660³N Engl J Med. 30, 2012; 367(9):826–833

CLIP

In November 2015, preclinical data were presented at the 2015 AACR-NCI-EORTC Molecular Targets and Cancer Therapeutics Conference in Boston, MA

Aurigene Collaboration (IRAK4 Inhibitor):

In October 2015, Curis exercised its option to exclusively license a program of orally available small molecule inhibitors of IRAK4 kinase, a serine/threonine kinase involved in innate immune responses as well as in certain hematologic cancers. The Company has since designated the development candidate as CA-4948 and expects to file an IND application for this molecule during 2016.

In November 2015, Curis’ collaborator Aurigene presented preclinical data from the IRAK4 program at the 2015 AACR-NCI-EORTC Molecular Targets and Cancer Therapeutics Conference in Boston, MA. This presentation included data from chemically distinct series of small molecule compounds with potent IRAK4 inhibitory activity in biochemical assays as well as in in vivo preclinical models, including MYD88 mutant DLBCL xenograft tumor models as well as a model of inflammatory disease.

CLIP

In April 2014, preclinical data presented at the CHI’s Ninth Drug Discovery Chemistry Conference in San Diego, CA, showed the compounds in vivo to have activity down to 10 mg/kg .

CLIP

10:50 Novel IRAK4 Inhibitors for Oncology and Inflammation

Susanta Samajdar, Ph.D., Research Director, Medicinal Chemistry, Aurigene Discovery Technologies Limited

This presentation will discuss the discovery and optimization of hit series, some preliminary in vivo data, combination therapy strategy, present focus and further advancements.

April 24-25 2014
Drug Discovery Chemistry – CHI’s Ninth Annual Conference: Fifth Annual Kinase inhibitor Chemistry, San Diego, CA, USA

Novel IRAK4 inhibitors

Susanta Samajdar from Aurigene Discovery Technologies presented the discovery of new IRAK4 (IL-1 receptor-associated kinase 4) inhibitors. Research began with a HTS campaign using two types of libraries: rationally designed novel scaffolds by hopping and morphing of known IRAK4 inhibitors and novel scaffolds identified by virtual screening of drug-like commercial library. A benzoxazol series was identified and crystallography was used to help their design. Lead optimization culminated in the identification of very potent compounds (AU-2807 and AU-2202) in cell assay (inflammation pathway and oncology pathway, respectively). The compounds were also active against Flt3 and KDR. Some PD in vivo data using LPS and TNFalpha release were presented in which the compound showed activity down to 10 mg/kg: no other in vivo model data were disclosed, but it was mentioned that studies in the CIA (collagen induced arthritis) model was ongoing. Dr Samajdar answered to three questions, one related to IRAK1 selectivity (the answer was that the compound is fully selective against IRAK1 and IRAK2). It was also mentioned that the compounds have a PBB higher than 98%. And the last question was related to the synergetic effect with BTK inhibitor in activated B-cell like diffuse large B-cell lymphoma, and this effect was observed with these compounds.

PATENT

http://www.google.com/patents/WO2013042137A1?cl=en

Compound-6: Synthesis of 6′-amino-N-(5-(cyclopropyIamino)-2-morpholinobenzo [d]oxazoI-6-yl)-[2,3′-bipyridine]-6-carboxamide.

Step_l^N-cyclopropyl-2-morpholino-6-nitrobenzo[d]oxazol-5-amine.

N-cyclopropyl-2-moφholino-6-nitrobenzo[d]oxazol-5-amine(0.7g,70%) was prepared from 5-fluoro-2-mo holino-6-nitrobenzo[d]oxazole(lg,Intermediate-2) by treating with cyciopropanamine in sealed tube at 100^°C for 8-14h. The progress of the reaction was monitored by TLC. After the reaction was completed, it was extracted with water (15ml) and dichioromethane (2x 15ml). The organic layer was collected, washed with brine, dried over sodium sulfate and concentrated under reduced pressure to get the crude. MS (ES) m/e 305(M+1, 50%).

Steg2:6-bromo-N-(5-(cyclopropylamino)-2-morpholinobenzo[d]oxazol-6-yl)

picolinamide.

Step Π and ii):The process of these steps are adopted from step 2 and step 3 of compound- 1.

Step3:6′-amino-N-(5-(cvclopropvlamino)-2-morpholinobenzord]oxazol-6-yl)-r2,3′- bipyridine]-6-carboxamide.

(i) N-(4-methoxybenzyl)-5-(4,4,5,5-tetramethyl-l ,3,2-dioxaborolan-2-yl)pyridin

Na₂C0₃, Pd(dppf)Cl₂, ACN, H₂0, 80-100°C, 8-14h; TFA, 60-70°C, 8-14h.

6′-amino-N-(5-(cyclopropylamino)-2-mo holinobenzo[d]oxazol-6-yl)-[2,3′-bipyridine]-6- carboxamide (0.03g,61%) was prepared from 6-bromo-N-(5-(cyclopropyIamino)-2- moφholinobenzo[d]o azoI-6-yl)picolinamide(0.07g, step-3) by following the same process used in step-1 and 2 of compound-3.

Ή NMR (400 MHz, DMSO-< ):6 1 1.63 (s, IH), 8.90 (s, IH), 8.61 (s, IH), 8.55 (s, IH), 8.37- 8.03 (m, 2H), 7.39 (s, IH), 6.80-6.62 (s, IH), 3.80-3.59 (m, 15H), 2.88-2.64 (m, 2H). MS (ESI): 472 (M+l , 60%).

PATENT

WO2015104688

Example 13

6′-amino-N-(2-morphol ne]-6-carboxamide

Step-1: Synthesis of 6-chloro thiazolo[4,5-c]pyridine-2(3H)-thione

Using the same reaction conditions as described in step 1 of example 1, 4,6-dichloropyridin-3-amine (1.3 g, 7 mmol) was cyclised using potassium ethyl xanthate (2.55 g, 15 mmol) in DMF (25mL) at 150°C for 8h to afford the title compound (1.3 g, 86.6 %) as a light brown solid.

1HNMR (400 MHz, DMSO-d₆): δ 14.2-14.0 (b, 1H), 8.274 (s, 1H), 7.931 (s, 1H); LCMS: 100%, m/z = 201.3 (M+l)⁺.

Step-2: Synthesis of 4-(6-chloro thiazolo[4,5-c]pyridin-2-yl) morpholine

To a suspension of 6-chlorothiazolo[4,5-c]pyridine-2(3H)-thione (0.3 g, 1.16 mmol) in

DCM (4 mL), oxalyl chloride (0.2 mL, 2.38 mmol) and DMF (1.5 mL) were added at 0°C. The resulting mixture was slowly allowed to warm to room temperature and stirred there for 1 h. The reaction mixture was again cooled to 0°C and triethyl amine (0.66 mL, 4.76 mmol) and morpholine (0.13 mL, 1.75 mmol) were added. The reaction mixture was stirred at RT for 1 h and quenched with water and extracted with ethyl acetate. The combined organic layers were washed with water, brine, dried over sodium sulphate and concentrated under reduced pressure. The crude material was purified by column chromatography (EtOAc/n-hexanes 3:7) to afford the title compound (0.14 g, 39.6 %) as a light brown solid.

1H NMR (400 MHz, DMSO-d₆): δ 8.47 (s, 1H), 8.04 (s, 1H), 3.74-3.72 (m, 4H), 3.61-3.59 (m, 4H); LCMS: m/z = 256.1 (M+l)⁺.

Step-3: Synthesis of 6′-amino-/V-(2-morpholino thiazolo [4,5-c]pyridin-6-yl)-[2,3′-bipyridine]-6-carboxamide

Using the same reaction conditions as described in step 4 of example 12, 4-(6-chlorothiazolo[4,5-c] pyridin-2-yl) morpholine (0.081 g, 0.32 mmol), was coupled with tert-butyl (6-carbamoyl-[2,3′-bipyridin]-6′-yl)carbamate (intermediate 2) (0.1 g, 0.32 mmol) using cesium carbonate (0.21 g, 0.64 mmol), XantPhos (0.028g, 0.047mmol) and Pd₂(dba)₃ (0.015 mg, 0.015 mmol) in toluene : dioxane (2:2mL) to get the crude product. The resultant crude was purified by 60-120 silica gel column chromatography using 2% methanol in DCM as eluent. Further the resultant crude was purified by prep HPLC to afford title compound (0.01 g, 6 %) as an off-white solid.

1H NMR (400 MHz, DMSO-d₆): δ 10.65 (s, 1H), 8.88 (d, 1H), 8.85 (dd, 1H), 8.71 (s, 1H), 8.55 (s, 1H), 8.22-8.13 (m, 4 H), 7.09 (d, 1H), 3.73 (t, 4H), 3.58 (t, 4H). LCMS: 100%, m/z = 434.2 (M+l)⁺.

Example 11

(S)-2-(2-methylpyridin-4-yl)-N-(2-morpholino-5-(pyrrolidin-3-ylamino)oxazolo[4,5-b]pyridin-6-yl)oxazole-4-carboxamide

Step l:Preparation of (S)-tert-butyl 3-((2-morpholino-6-nitrooxazolo[4,5-b]pyridin-5-yl)amino)pyrrolidine- 1 -carboxylate

A solution of 5-chloro-2-morpholino-6-nitrooxazolo[4,5-b]pyridine (300mg, 1.0563 mmol) (S)-tert-butyl 3 -aminopyrrolidine- 1 -carboxylate (237mg, 1.267 mmol) and potassium carbonate (292mg, 2.112 mmol) in DMF (2mL) was heated at 100°C for 2h. Reaction was quenched with ice water and filtered the solid. The resultant crude was purified by 60-120 silica gel column chromatography using 1 % methanol in DCM as eluent to obtain the title compound (350mg, 76.25%). LCMS: m/z: 435.4 (M+l)⁺.

Step 2:Preparation of (S)-tert-butyl 3-((6-amino-2-morpholinooxazolo[4,5-b]pyridin-5-yl)amino)pyrrolidine- 1 -carboxylate

Using the same reaction conditions as described in step 5 of example 1, (S)-tert-butyl 3- ((2-morpholino-6-nitrooxazolo[4,5-b]pyridin-5-yl)amino)pyrrolidine-l -carboxylate (350mg, 0.806 mmol) was reduced with zinc dust (422mg, 6.451 mmol) and ammonium chloride (691mg, 12.903 mmol) in THF/methanol/H₂0 (10mL/2mL/lmL) to get the title compound (240mg, 71.8%). LCMS: m/z: 405.2 (M+l)⁺.

Step 3:Preparation of (S)-tert-butyl 3-((6-(2-(2-methylpyridin-4-yl)oxazole-4-carboxamido)-2-morpholinooxazolo[4,5-b]pyridin-5-yl)amino)pyrrolidine-l-carboxylate

Using the same reaction conditions as described in step 6 of example 1, (S)-tert-butyl 3-((6-amino-2-morpholinooxazolo[4,5-b]pyridin-5-yl)amino)pyrrolidine-l -carboxylate (115mg, 0.284 mmol), was coupled with 2-(2-methylpyridin-4-yl)oxazole-4-carboxylic acid (70mg, 0.341 mmol) using EDCI.HCl (82mg, 0.426 mmol), HOBt (58mg, 0.426 mmol), DIPEA (0.199mL, 1.138 mmol) in DMF (2mL) to afford the title compound (lOOmg, 59.52%). LCMS: m/z: 591.4 (M+l)⁺.

Step 4: Preparation of (S)-2-(2-methylpyridin-4-yl)-N-(2-morpholino-5-(pyrrolidin-3-ylamino)oxazolo[4,5-b]pyridin-6-yl)oxazole-4-carboxamide

Using the same reaction conditions as described in step 8 of example 1, (S)-tert-butyl 3- ((6-(2-(2-methylpyridin-4-yl)oxazole-4-carboxamido)-2-morpholinooxazolo[4,5-b]pyridin-5-yl)amino)pyrrolidine-l -carboxylate (lOOmg, 0.169 mmol) was deprotected using methanolic HC1 (5mL) to get the crude product. This was then purified by prep HPLC to get the title compound (9mg, 10.84%).

1HNMR (CDCI₃, 400MHz): δ 9.91 (s, 1H), 8.78 (s, 1H), 8.74-8.73 (d, 1H), 8.45 (s, 1H), 7.82 (s, 1H), 7.76-7.74 (d, 1H), 4.50 (s, 1H), 4.04-4.03 (d, 4H), 3.30-3.00 (m, 7H), 2.70 (s, 3H), 2.40-1.80 (m, 4H), 1.00-0.08 (m, 1H). LCMS: 100%, m/z = 491.3 (M+l)⁺.

REFERENCES

http://www.curis.com/images/stories/pdfs/posters/Aurigene_IRAK4_AACR-NCI-EORTC_2015.pdf

http://www.curis.com/images/stories/pdfs/posters/Aurigene_IRAK4_AACR_20150421.pdf

¹Nature. 2011; 470(7332):115–119

²Immunology and Cell Biology. 2011; 89(6):659–660

³N Engl J Med. 30, 2012; 367(9):826–833

April 2014, preclinical data presented at the CHI’s Ninth Drug Discovery Chemistry Conference in San Diego, CA

November 2015, preclinical data were presented at the 2015 AACR-NCI-EORTC Molecular Targets and Cancer Therapeutics Conference in Boston, MA

http://pubs.acs.org/doi/abs/10.1021/jm5016044

http://cancerres.aacrjournals.org/content/75/15_Supplement/3646

2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 3646. doi:10.1158/1538-7445.AM2015-3646

////////IRAK4 Kinase Inhibitor, Curis,  Aurigene,  CA 4948, AU 4948, CA-4948, AU-4948, 1428335-77-6

c21ccc(cc1sc(n2)N3CCOCC3)NC(c4nc(ccc4)c5ccc(nc5)N)=O