alpha-Piperidine-beta-sulfone hydroxamate derivatives were explored that are potent for matrix metalloproteinases (MMP)-2, -9, and -13 and are sparing of MMP-1. The investigation of the beta-sulfones subsequently led to the discovery of hitherto unknown alpha-sulfone hydroxamates that are superior to the corresponding beta-sulfones in potency for target MMPs, selectivity vs MMP-1, and exposure when dosed orally. alpha-Piperidine-alpha-sulfone hydroxamate 35f (SC-276) was advanced through antitumor and antiangiogenesis assays and was selected for development. Compound 35f demonstrates excellent antitumor activity vs MX-1 breast tumor in mice when dosed orally as monotherapy or in combination with paclitaxel.

α-Sulfone-α-piperidine and α-tetrahydropyranyl hydroxamates were explored that are potent inhibitors of MMP's-2, -9, and -13 that spare MMP-1, with oral efficacy in inhibiting tumor growth in mice and left-ventricular hypertrophy in rats and in the bovine cartilage degradation ex vivo explant system. α-Piperidine 19v (SC-78080/SD-2590) was selected for development toward the initial indication of cancer, while α-piperidine and α-tetrahydropyranyl hydroxamates 19w (SC-77964) and 9i (SC-77774), respectively, were identified as backup compounds.

SummaryTo investigate the functional roles of individual HLA-DR residues in T cell recognition, transfectants expressing wild-type or mutant DR(o~, B1"0401) molecules with single amino acid substitutions at 14 polymorphic positions of the DI~1"0401 chain or 19 positions of the DRo~ chain were used as antigen-presenting cells for five T cell clones specific for the influenza hemagglutinin peptide, HA307-19. Of the six polymorphic positions in the DRB floor that were examined, mutations at only two positions eliminated T cell recognition: positions 13 (four clones) and 28 (one clone). In contrast, individual mutations at DRB positions 70, 71, 78, and 86 on the oe helix eliminated recognition by each of the dones, and mutations at positions 74 and 67 eliminated recognition by four and two clones, respectively. Most of the DRol mutations had minimal or no effect on most of the clones, although one clone was very sensitive to changes in the DRo~ chain, with loss of recognition in response to 10 mutants. Mutants that abrogated recognition by all of the clones were assessed for peptide binding, and only the B86 mutation drastically decreased peptide binding. Single amino acid substitutions at polymorphic positions in the central part of the DRB c~ helix disrupted T cell recognition much more frequently than substitutions in the floor, suggesting that DRB residues on the ol helix make relatively greater contributions than those in the floor to the ability of the DR(oe,~l*0401) molecule to present HA307-19. The data indicate that DRq8 residues 13, 70, 71, 74, and 78, which are located in pocket 4 of the peptide binding site in the crystal structure of the DR1 molecule, exert a major and disproportionate influence on the outcome of T cell recognition, compared with other polymorphic residues.T he MHC molecules on the cell surface have evolved the remarkable capacity to bind and present to T lymphocytes an extremely large number of structurally diverse peptides. Recognition of the appropriate peptide-class II complexes by the antigen-specific TCR leads to CD4 + T cell proliferation and a cascade of cellular immune responses. HLA class II molecules are highly polymorphic, and this structural polymorphism determines the distinct peptide-binding and antigen presentation characteristics of each molecule. However, the functional roles of individual residues in HLA class II molecules in peptide binding and T cell recognition have not been dearly defined. Elucidation of the ways in which class II residues interact with peptides and TCR may have important implications for understanding the function of the This study was presented in part as an abstract at the 19th annual meeting of the American Society for Histocompatibility and Immunogenetics, Phoenix, Arizona, 2-7 October, 1993. immune system, as well as for the treatment ofimmunologically mediated diseases.Considerable progress has been made in the understanding of the structure of HLA class II molecules and the nature of class II-peptide interactions in recent years. Based ...

ABSTRACT:In an effort to develop a novel therapeutic agent aimed at addressing the unmet need of patients with osteoarthritis pain, we set out to develop an inhibitor for autotaxin with excellent potency and physical properties to allow for the clinical investigation of autotaxin-induced nociceptive and neuropathic pain. An initial hit identification campaign led to an aminopyrimidine series with an autotaxin IC 50 of 500 nM. X-ray crystallography enabled the optimization to a lead compound that demonstrated favorable potency (IC 50 = 2 nM), PK properties, and a robust PK/PD relationship. KEYWORDS: Autotaxin, tool molecule, osteoarthritis, LPA O steoarthritis (OA) is a highly prevalent disease affecting many adults including more than one out of three individuals aged 65 or older in the United States.1 In addition to significant accompanying pain, OA frequently leads to pronounced disability resulting in the loss of work, hospitalization, and joint replacement procedures.2 Current first-line pharmacological treatment options for OA focus on reducing inflammation and the associated pain. Nonsteroidal antiinflammatory drugs (NSAIDS) and selective COX-2 inhibitors are among the most prescribed medications for OA pain but unfortunately are also frequently accompanied by gastrointestinal, renal, and CV side effects, limiting their use. 3 Recently, the role of lyosophosphatidic acid (LPA) in certain inflammatory conditions has been studied. 4 LPA exists as a number of molecular species that have variable saturated and unsaturated fatty acid chains.5 Signaling of LPA through six GPCRs (LPA Receptors 1−6) has been shown to lead to the upregulation of inflammatory cytokines and matrix metalloproteinases, which contribute to the pathogenesis of OA. 6LPA signaling has also been associated with many other pathologies, such as pulmonary fibrosis and cancer. In vivo, the enzyme autotaxin (ATX), with lyosophosopholipase D activity, is the primary source of extracellular LPA, which results from the cleavage of choline from lysophosphatidylcholine (LPC) (Figure 1). LPA is also produced through action of secreted phospholipases A2 (sPLA2) on phosphatidic acid (PA), although this is believed to be a minor route of extracellular LPA production in vivo. 8,9 Autotaxin is an extracellular, 125 kDa protein that was originally characterized in 1993 by Stracke et al. as a motility stimulating protein. 10 In 2002, Umezu-Goto and co-workers demonstrated that ATX was the same protein as a known lysophopholipase D enzyme, which catalyzed the conversion of LPC to LPA.11 Autotaxin is a multidomain protein with two Nterminal somatomedin B-like domains, a centrally located phosphodiesterase domain, and a catalytically inactive nuclease-like domain on the C-terminal region. It is expressed in four main isoforms (ATXα−δ) with largely unknown differential functionality in vivo.7 The catalytic domain of ATX comprises two zinc ions coordinated with histidine and aspartic acid residues with a threonine alcohol serving as the nucleophile. A large hydro...

We have developed a novel ELISA using an optimized ARGS antibody and have demonstrated for the first time, an ELISA-based measurement of aggrecan degradation products in human serum and urine. This assay has the potential to serve as a mechanistic drug activity biomarker in the clinic and is expected to significantly impact/accelerate the clinical development of aggrecanase inhibitors and other disease modifying drugs for OA.