A Potent and Selective S1P1 Antagonist with Efficacy in Experimental Autoimmune Encephalomyelitis

SummaryLymphocyte trafficking is critically regulated by the Sphingosine 1-phosphate receptor-1 (S1P1), a G protein-coupled receptor that has been highlighted as a promising therapeutic target in autoimmunity. Fingolimod (FTY720, Gilenya) is a S1P1 receptor agonist that has recently been approved for the treatment of multiple sclerosis (MS). Here, we report the discovery of NIBR-0213, a potent and selective S1P1 antagonist that induces long-lasting reduction of peripheral blood lymphocyte counts after oral dosing. NIBR-0213 showed comparable therapeutic efficacy to fingolimod in experimental autoimmune encephalomyelitis (EAE), a model of human MS. These data provide convincing evidence that S1P1 antagonists are effective in EAE. In addition, the profile of NIBR-0213 makes it an attractive candidate to further study the consequences of S1P1 receptor antagonism and to differentiate the effects from those of S1P1 agonists

An oral S1P1 antagonist prodrug with efficacy in vivo: discovery, synthesis and evaluation

A prodrug approach to optimize the oral exposure of an S1P1 antagonist for chronic efficacy studies led to the discovery of (S)-2-{[3'-(4-Chloro-2,5-dimethyl-benzenesulfonylamino)-3,5-dimethyl-biphenyl-4-carbonyl]-methyl-amino}-4-dimethylamino-butyric acid methyl ester (BVM924). Due to the steric hindrance and the partial double bond character of the amide group and the resulting large rotational barrier around the amide bond two conformers of (BVM924) can be detected in solution and their equilibration was investigated by UPLC and 1H NMR. Methyl ester prodrug (BVM924) is hydrolyzed in vivo to the corresponding carboxylic acid (BVS819), a potent and selective S1P1 antagonist. Oral administration of the prodrug (BVM924) induces sustained peripheral lymphocyte depletion in rats. In a rat cardiac transplantation model co-administration of a nonefficacious dose of prodrug (BVM924) with a nonefficacious dose of sotrastaurin (AEB071), a protein kinase C inhibitor, or everolimus (RAD001), an mTOR inhibitor, effectively prolonged the survival time of rat cardiac allografts. This demonstrates that clinically useful immunomodulation mediated by the S1P1 receptor can be achieved with an S1P1 antagonist generated in vivo after oral administration of its prodrug

Design and preparation of 2-benzamido-pyrimidines as inhibitors of IKK.

The design, synthesis, and the biological evaluation of 2-benzamido-pyrimidines as novel IKK inhibitors are described. By optimization of the lead compound 3, compounds 16 and 24 are identified as good inhibitors of IKK2 with IC(50) values of 40 and 25 nM, respectively. Compound 16 also demonstrated significant in vivo activity in an acute model of cytokine release

Ce-4 Si4O4N6 O - A hyperbolically layered oxonitridosilicate oxide with an ordered distribution of oxygen and nitrogen

The yellow-orange oxonitridosilicate oxide Ce-4[Si4O4N6]O was obtained by the reaction of cerium metal with Si(NH)(2) and SiO2 in a radiofrequency furnace at 1560 degrees C, The crystal structure was determined by single-crystal X-ray diffraction (a = 1033.67(6) pm, P2(1)3, Z = 4. R1 = 0.0412, wR2 = 0.0678) and powder neutron diffraction, In the solid there are complex cations [Ce4O](10+) that are enveloped by a hyperbolical layer structure [Si4O4N6](10-). The layer is built up by corner-sharing SiON3 tetrahedra of Q(3) type The oxygen atoms of the SiON3 tetrahedra are terminally bound to Si, while all nitrogen atoms bridge two neighboring Si centres, The crystallographic differentiation of O and N was unequivocally possible by a careful evaluation of the single-crystal X-ray diffraction data combined with lattice-energy calculations by using the MAPLE concept (Madelung part of lattice energy). Furthermore the results were confirmed by the chemical analyses. Subsequently, the determined N/O distribution and their crystallographic ordering was proved by neutron powder diffraction, In accordance with the molar ratio Si:(O,N) = 2:5 the [Si4O4N6](10-) network may be classified as a layer silicate. In this specific case a hyperbolically corrugated topology of the layers is observed; this is correlated to periodic nodal surface (PNS) representatives

Novel CCR1 antagonists with oral activity in the mouse collagen induced arthritis.

Cinnamides as novel CCR1 antagonist chemotypes are described with high affinity to human and rodent receptors. A1B1 and A4B7 showed oral activity in the mouse collagen induced arthritis

Discovery of Amino Alcohols as Highly Potent, Selective, and Orally Efficacious Inhibitors of Leukotriene A4 Hydrolase.

The discovery of chiral amino alcohols derived from our previously disclosed clinical LTA4H inhibitor LYS006 is described. In a biochemical assay, their optical antipodes showed similar potencies, which could be rationalized by the cocrystal structures of these compounds bound to LTA4H. Despite comparable stabilities in liver microsomes, they showed distinct in vivo PK properties. Selective O-phosphorylation of the (R)-enantiomers in blood led to clearance values above the hepatic blood flow, whereas the (S)-enantiomers were unaffected and exhibited satisfactory metabolic stabilities in vivo. Introduction of two pyrazole rings led to compound (S)-2 with a more balanced distribution of polarity across the molecule, exhibiting high selectivity and excellent potency in vitro and in vivo. Furthermore, compound (S)-2 showed favorable profiles in 16-week IND-enabling toxicology studies in dogs and rats. Based on allometric scaling and potency in whole blood, compound (S)-2 has the potential for a low oral efficacious dose administered once daily

An Oral Sphingosine 1‑Phosphate Receptor 1 (S1P₁) Antagonist Prodrug with Efficacy in Vivo: Discovery, Synthesis, and Evaluation

A prodrug approach to optimize the oral exposure of a series of sphingosine 1-phosphate receptor 1 (S1P₁) antagonists for chronic efficacy studies led to the discovery of (<i>S</i>)-2-{[3′-(4-chloro-2,5-dimethylphenylsulfonylamino)-3,5-dimethylbiphenyl-4-carbonyl]­methylamino}-4-dimethylaminobutyric acid methyl ester <b>14</b>. Methyl ester prodrug <b>14</b> is hydrolyzed in vivo to the corresponding carboxylic acid <b>15</b>, a potent and selective S1P₁ antagonist. Oral administration of the prodrug <b>14</b> induces sustained peripheral blood lymphocyte reduction in rats. In a rat cardiac transplantation model coadministration of a nonefficacious dose of prodrug <b>14</b> with a nonefficacious dose of sotrastaurin (<b>19</b>), a protein kinase C inhibitor, or everolimus (<b>20</b>), an mTOR inhibitor, effectively prolonged the survival time of rat cardiac allografts. This demonstrates that clinically useful immunomodulation mediated by the S1P₁ receptor can be achieved with an S1P₁ antagonist generated in vivo after oral administration of its prodrug

Pathophysiological Consequences of a Break in S1P1-Dependent Homeostasis of Vascular Permeability Revealed by S1P1 Competitive Antagonism

<div><p>Rational</p><p>Homeostasis of vascular barriers depends upon sphingosine 1-phosphate (S1P) signaling via the S1P1 receptor. Accordingly, S1P1 competitive antagonism is known to reduce vascular barrier integrity with still unclear pathophysiological consequences. This was explored in the present study using NIBR-0213, a potent and selective S1P1 competitive antagonist.</p><p>Results</p><p>NIBR-0213 was tolerated at the efficacious oral dose of 30 mg/kg BID in the rat adjuvant-induced arthritis (AiA) model, with no sign of labored breathing. However, it induced dose-dependent acute vascular pulmonary leakage and pleural effusion that fully resolved within 3–4 days, as evidenced by MRI monitoring. At the supra-maximal oral dose of 300 mg/kg QD, NIBR-0213 impaired lung function (with increased breathing rate and reduced tidal volume) within the first 24 hrs. Two weeks of NIBR-0213 oral dosing at 30, 100 and 300 mg/kg QD induced moderate pulmonary changes, characterized by alveolar wall thickening, macrophage accumulation, fibrosis, micro-hemorrhage, edema and necrosis. In addition to this picture of chronic inflammation, perivascular edema and myofiber degeneration observed in the heart were also indicative of vascular leakage and its consequences.</p><p>Conclusions</p><p>Overall, these observations suggest that, in the rat, the lung is the main target organ for the S1P1 competitive antagonism-induced acute vascular leakage, which appears first as transient and asymptomatic but could lead, upon chronic dosing, to lung remodeling with functional impairments. Hence, this not only raises the question of organ specificity in the homeostasis of vascular barriers, but also provides insight into the pre-clinical evaluation of a potential safety window for S1P1 competitive antagonists as drug candidates.</p></div