Nigel Graham Cooke

The selective sphingosine 1-phosphate receptor modulator BAF312 redirects lymphocyte distribution and has species-specific effects on heart rate

BAF312 is a next‐generation sphingosine 1‐phosphate (S1P) receptor modulator, selective for S1P1 and S1P5 receptors. S1P1 receptors are essential for lymphocyte egress from lymph nodes and a drug target in immune‐mediated diseases. Here, we have characterized the immunomodulatory potential of BAF312 and the S1P receptor‐mediated effects on heart rate using preclinical and human data.

Discovery of 3-(1H-indol-3-yl)-4-[2-(4-methylpiperazin-1-yl)quinazolin-4-yl]pyrrole-2,5-dione (AEB071), a potent and selective inhibitor of protein kinase C isotypes

A series of novel maleimide-based inhibitors of protein kinase C (PKC) were designed, synthesized, and evaluated. AEB071 (1) was found to be a potent, selective inhibitor of classical and novel PKC isotypes. 1 is a highly efficient immunomodulator, acting via inhibition of early T cell activation. The binding mode of maleimides to PKCs, proposed by molecular modeling, was confirmed by X-ray analysis of 1 bound in the active site of PKCalpha.

Total synthesis of (±)-rocaglamide and some aryl analogues

Abstract The insecticidal activity found for rocaglamide and its congeners, prompted us to establish a short and efficient synthesis of the natural product and some synthetic ‘halo-aryl’ analogues. Pd-catalysed cross-coupling reactions of the bromo analogue were then explored in order to gain a suitable access to a broad range of unnatural analogues. The key step of our approach is a keto-aldehyde acyloin ring-closure followed by a Stiles carboxylation.

Discovery of BAF312 (Siponimod), a Potent and Selective S1P Receptor Modulator

A novel series of alkoxyimino derivatives as S1P1 agonists were discovered through de novo design using FTY720 as the chemical starting point. Extensive structure-activity relationship studies led to the discovery of (E)-1-(4-(1-(((4-cyclohexyl-3-(trifluoromethyl)benzyl)oxy)imino)ethyl)-2-ethylbenzyl)azetidine-3-carboxylic acid (32, BAF312, Siponimod), which has recently completed phase 2 clinical trials in patients with relapsing-remitting multiple sclerosis.

Chemistry of GABAB Modulators

Nearly 10 yr have passed since the authors review “Chemistry of GABAB Modulators” appeared in the book “The GABA Receptors,” 2nd edition, edited by S. J. Enna and N. G. Bowery, Humana Press, Totowa, 1997 (1). In this update the authors wish to outline only new developments not covered in the 1997 paper. Baclofen, synthesized for the first time in September 1962, is still the only γ-aminobutyric acid (GABAB)-receptor agonist marketed for the treatment of spasticity and trigeminal neuralgia. It is fascinating to learn how many highly competent chemists devised manifold and elegant synthetic procedures for either racemic or (R)-(−)-baclofen and the structurally closely related potent antidepressant (R)-(−)-Rolipram, a selective phosphodiesterase-4 inhibitor. The new syntheses published after 1996 are listed in alphabetical order (2–16). Very recently a prodrug of (R)-(−)-baclofen (Fig. 1) was described which enhanced the oral bioavailability in Cynomolgus monkeys to more than 80% (17). It is planned to test this prodrug in clinical trials for the treatment of spasticity and gastroesophageal reflux disease.

Structure-activity relationship and pharmacokinetic studies of sotrastaurin (AEB071), a promising novel medicine for prevention of graft rejection and treatment of psoriasis.

Protein kinase C (PKC) isotypes have emerged as key targets for the blockade of early T-cell activation. Herein, we report on the structure-activity relationship and the detailed physicochemical and in vivo pharmacokinetic properties of sotrastaurin (AEB071, 1), a novel maleimide-based PKC inhibitor currently in phase II clinical trials. Most notably, the preferred uptake of sotrastaurin into lymphoid tissues is an important feature, which is likely to contribute to its in vivo efficacy.

Discovery of CDZ173 (leniolisib), Representing a Structurally Novel Class of PI3K Delta-Selective Inhibitors

The predominant expression of phosphoinositide 3-kinase δ (PI3Kδ) in leukocytes and its critical role in B and T cell functions led to the hypothesis that selective inhibitors of this isoform would have potential as therapeutics for the treatment of allergic and inflammatory disease. Targeting specifically PI3Kδ should avoid potential side effects associated with the ubiquitously expressed PI3Kα and β isoforms. We disclose how morphing the heterocyclic core of previously discovered 4,6-diaryl quinazolines to a significantly less lipophilic 5,6,7,8-tetrahydropyrido[4,3-d]pyrimidine, followed by replacement of one of the phenyl groups with a pyrrolidine-3-amine, led to a compound series with an optimal on-target profile and good ADME properties. A final lipophilicity adjustment led to the discovery of CDZ173 (leniolisib), a potent PI3Kδ selective inhibitor with suitable properties and efficacy for clinical development as an anti-inflammatory therapeutic. In vitro, CDZ173 inhibits a large spectrum of immune cell functions, as demonstrated in B and T cells, neutrophils, monocytes, basophils, plasmocytoid dendritic cells, and mast cells. In vivo, CDZ173 inhibits B cell activation in rats and monkeys in a concentration- and time-dependent manner. After prophylactic or therapeutic dosing, CDZ173 potently inhibited antigen-specific antibody production and reduced disease symptoms in a rat collagen-induced arthritis model. Structurally, CDZ173 differs significantly from the first generation of PI3Kδ and PI3Kγδ-selective clinical compounds. Therefore, CDZ173 could differentiate by a more favorable safety profile. CDZ173 is currently in clinical studies in patients suffering from primary Sjögrens syndrome and in APDS/PASLI, a disease caused by gain-of-function mutations of PI3Kδ.

Reduced cardiac side-effect potential by introduction of polar groups: discovery of NIBR-1282, an orally bioavailable CCR5 antagonist which is active in vivo.

Introduction of polar groups in a series of potent CCR5 antagonists which are very likely to adversely affect the conduction system in the heart led to the identification of NIBR-1282 which did not show adverse effects when tested in an isolated rabbit heart ex vivo model. Administration of NIBR-1282 in combination with a non-efficacious dose of CsA led to significant prolongation of kidney allograft survival in cynomolgus monkeys.

Chapter 16 Sphingosine 1-Phosphate Type 1 Receptor Modulators: Recent Advances and Therapeutic Potential

Publisher Summary Sphingosine 1-phosphate (S1P) is a naturally occurring sphingolipid mediator that functions both as an intracellular messenger in many different types of cells and as an extracellular signaling molecule. S1P plays fundamental physiological roles in a number of processes including vascular stabilization, heart development, lymphocyte homing, and cancer angiogenesis. The discovery of FTY720 and the high degree of efficacy seen with FTY720 in a wide range of pre-clinical models of autoimmune diseases have been the catalyst for extensive research efforts into the S1P receptors. The discovery of FTY720 and the unique role of S1P receptors in the trafficking of lymphocytes have catalysed intensive research in this area. Two different hypotheses have been proposed to explain the mechanism by which S1P receptor agonists reduce the levels of peripheral lymphocytes. The first hypothesis suggests that agonism of S1P1 receptors on lymphocytes induces internalization of the receptor, resulting in a blockade of S1P-directed migration of the lymphocytes from the lymph nodes. The second hypothesis suggests that agonism of S1P1 receptors on the lymphatic endothelium leads to an increase in barrier function and a reduction in lymphocyte transmigration. Significant progress has been achieved towards S1P subtype-selective agonists and antagonists with suitable pharmacokinetic properties for in vivo studies.

Synthesis of the carbocyclic analogue of (±)-Rocaglamide

Abstract The carbocyclic analogue of (±)-Rocaglamide 1 , in which the ring oxygen of the 2,3-dihydrobenzofuran has been replaced by a methylene group, was synthesised in 10 steps from cyclopentanone. A key feature of this route is a highly efficient intramolecular condensation reaction which cleanly leads to the tricyclic skeleton.