Discovery of the macrocycle 11-(2-pyrrolidin-1-yl-ethoxy)-14,19-dioxa-5,7,26-triaza-tetracyclo[19.3.1.1(2,6).1(8,12)]heptacosa-1(25),2(26),3,5,8,10,12(27),16,21,23-decaene (SB1518), a potent Janus kinase 2/fms-like tyrosine kinase-3 (JAK2/FLT3) inhibitor for the treatment of myelofibrosis and lympho

Discovery of the activating mutation V617F in Janus Kinase 2 (JAK2(V617F)), a tyrosine kinase critically involved in receptor signaling, recently ignited interest in JAK2 inhibitor therapy as a treatment for myelofibrosis (MF). Herein, we describe the design and synthesis of a series of small molecule 4-aryl-2-aminopyrimidine macrocycles and their biological evaluation against the JAK family of kinase enzymes and FLT3. The most promising leads were assessed for their in vitro ADME properties culminating in the discovery of 21c, a potent JAK2 (IC(50) = 23 and 19 nM for JAK2(WT) and JAK2(V617F), respectively) and FLT3 (IC(50) = 22 nM) inhibitor with selectivity against JAK1 and JAK3 (IC(50) = 1280 and 520 nM, respectively). Further profiling of 21c in preclinical species and mouse xenograft and allograft models is described. Compound 21c (SB1518) was selected as a development candidate and progressed into clinical trials where it is currently in phase 2 for MF and lymphoma.

[1]  J. Griffin,et al.  Role of FLT3 in leukemia. , 2002, Current opinion in hematology.

[2]  R. Kiss,et al.  Recent developments on JAK2 inhibitors: a patent review , 2010, Expert opinion on therapeutic patents.

[3]  Akira Suzuki,et al.  Synthetic studies via the cross-coupling reaction of organoboron derivatives with organic halides , 1991 .

[4]  P. Doherty,et al.  Defective Lymphoid Development in Mice Lacking Jak3 , 1995, Science.

[5]  P. Mclaughlin,et al.  Phase I Study of a Novel Oral JAK-2 Inhibitor SB1518 In Patients with Relapsed Lymphoma: Evidence of Clinical and Biologic Activity In Multiple Lymphoma Subtypes. , 2010 .

[6]  J. Fridman,et al.  Selective Inhibition of JAK1 and JAK2 Is Efficacious in Rodent Models of Arthritis: Preclinical Characterization of INCB028050 , 2010, The Journal of Immunology.

[7]  Ayalew Tefferi,et al.  Safety and efficacy of INCB018424, a JAK1 and JAK2 inhibitor, in myelofibrosis. , 2010, The New England journal of medicine.

[8]  P. Bonneau,et al.  Macrocyclic inhibitors of the NS3 protease as potential therapeutic agents of hepatitis C virus infection. , 2003, Angewandte Chemie.

[9]  Alexander Deiters,et al.  Synthesis of oxygen- and nitrogen-containing heterocycles by ring-closing metathesis. , 2004, Chemical reviews.

[10]  F. Lu,et al.  The structural basis for autoinhibition of FLT3 by the juxtamembrane domain. , 2004, Molecular cell.

[11]  M. Lorenzi,et al.  Janus Kinase 2 (JAK2) Inhibitors for the Treatment of Myeloproliferative Neoplasm (MPN) , 2010 .

[12]  Norio Miyaura,et al.  Palladium-Catalyzed Cross-Coupling Reactions of Organoboron Compounds , 1995 .

[13]  T. Mattfeldt,et al.  Mutations of the tumor suppressor gene SOCS-1 in classical Hodgkin lymphoma are frequent and associated with nuclear phospho-STAT5 accumulation , 2006, Oncogene.

[14]  N. Srinivasan,et al.  Iron-Ammonium Chloride - A Convenient and Inexpensive Reductant , 1992 .

[15]  N. K. Williams,et al.  Dissecting specificity in the Janus kinases: the structures of JAK-specific inhibitors complexed to the JAK1 and JAK2 protein tyrosine kinase domains. , 2009, Journal of molecular biology.

[16]  S. Rane,et al.  Janus kinases: components of multiple signaling pathways , 2000, Oncogene.

[17]  H. Deeg,et al.  Phase I Dose-Escalation Trial of SB1518, a Novel JAK2/FLT3 Inhibitor, in Acute and Chronic Myeloid Diseases, Including Primary or Post-Essential Thrombocythemia/ Polycythemia Vera Myelofibrosis. , 2009 .

[18]  H. Deeg,et al.  Phase 1/2 Study of SB1518, a Novel JAK2/FLT3 Inhibitor, In the Treatment of Primary Myelofibrosis , 2010 .

[19]  S. Verstovsek,et al.  JAK2 inhibitors: what's the true therapeutic potential? , 2011, Blood reviews.

[20]  L. Johnson,et al.  Protein kinase inhibition by staurosporine revealed in details of the molecular interaction with CDK2 , 1997, Nature Structural Biology.

[21]  H. Rao,et al.  A convenient procedure for the synthesis of allyl and benzyl ethers from alcohols and phenols , 2001 .

[22]  S. G. Joshi,et al.  An Improved Synthesis of Etravirine , 2010 .

[23]  Stefan N. Constantinescu,et al.  A unique clonal JAK2 mutation leading to constitutive signalling causes polycythaemia vera , 2005, Nature.

[24]  S. Neidle,et al.  Rationally designed analogues of tamoxifen with improved calmodulin antagonism. , 1995, Journal of medicinal chemistry.

[25]  T. Boggon,et al.  Crystal structure of the Jak3 kinase domain in complex with a staurosporine analog. , 2005, Blood.

[26]  P. Eilbracht,et al.  Tandem hydroformylation/Fischer indole synthesis: a novel and convenient approach to indoles from olefins. , 2003, Organic letters.

[27]  M. Hesse,et al.  Ring closure methods in the synthesis of macrocyclic natural products , 1993 .

[28]  T. N. Bhat,et al.  The Protein Data Bank , 2000, Nucleic Acids Res..

[29]  S. You,et al.  Asymmetric construction of polycyclic indoles through olefin cross-metathesis/intramolecular Friedel-Crafts alkylation under sequential catalysis. , 2009, Angewandte Chemie.

[30]  D. Linch,et al.  Prognostic Implications of the Presence of FLT3 Mutations in Patients with Acute Myeloid Leukemia , 2003, Leukemia & lymphoma.

[31]  A. Poulsen,et al.  SB1518, a novel macrocyclic pyrimidine-based JAK2 inhibitor for the treatment of myeloid and lymphoid malignancies , 2011, Leukemia.

[32]  P. Campbell,et al.  Acquired mutation of the tyrosine kinase JAK2 in human myeloproliferative disorders , 2005, The Lancet.

[33]  W. L. Jorgensen,et al.  Development and Testing of the OPLS All-Atom Force Field on Conformational Energetics and Properties of Organic Liquids , 1996 .

[34]  J. Rossjohn,et al.  The structural basis of Janus kinase 2 inhibition by a potent and specific pan-Janus kinase inhibitor. , 2006, Blood.

[35]  Stephen P. Hale,et al.  The exploration of macrocycles for drug discovery — an underexploited structural class , 2008, Nature Reviews Drug Discovery.

[36]  E. Graziani,et al.  Recent advances in the chemistry, biosynthesis and pharmacology of rapamycin analogs. , 2009, Natural product reports.

[37]  Andreas Kowarsch,et al.  Dynamic mathematical modeling of IL13-induced signaling in Hodgkin and primary mediastinal B-cell lymphoma allows prediction of therapeutic targets. , 2011, Cancer research.

[38]  Sandra A. Moore,et al.  Activating mutation in the tyrosine kinase JAK2 in polycythemia vera, essential thrombocythemia, and myeloid metaplasia with myelofibrosis. , 2005, Cancer cell.

[39]  D. Gilliland.  FLT3-activating mutations in acute promyelocytic leukaemia: a rationale for risk-adapted therapy with FLT3 inhibitors. , 2003, Best practice & research. Clinical haematology.

[40]  A. Tefferi,et al.  CYT387, a selective JAK1/JAK2 inhibitor: in vitro assessment of kinase selectivity and preclinical studies using cell lines and primary cells from polycythemia vera patients , 2009, Leukemia.

[41]  D. Boschelli,et al.  First generation 5-vinyl-3-pyridinecarbonitrile PKCtheta inhibitors. , 2009, Bioorganic & medicinal chemistry letters.

[42]  R. Levine,et al.  Mechanisms of mutations in myeloproliferative neoplasms. , 2009, Best practice & research. Clinical haematology.

[43]  W. C. Still,et al.  A rapid approximation to the solvent accessible surface areas of atoms , 1988 .

[44]  Bernd Schmidt,et al.  Ruthenium-catalyzed cyclizations: more than just olefin metathesis! , 2003, Angewandte Chemie.

[45]  C. D. Jones,et al.  Regioselectivity in the Alkaline Thiolate Deprotection of Aryl Methyl Ethers , 1995 .

[46]  E. Montserrat,et al.  Regulation of JAK2 by miR-135a: prognostic impact in classic Hodgkin lymphoma. , 2009, Blood.

[47]  A. Tefferi.  JAK and MPL mutations in myeloid malignancies , 2008, Leukemia & lymphoma.

[48]  J. Reilly.  FLT3 and its Role in the Pathogenesis of Acute Myeloid Leukaemia , 2003, Leukemia & lymphoma.

[49]  T. Naoe,et al.  Oncogenic protein tyrosine kinases , 2004, Cellular and Molecular Life Sciences CMLS.