Tawfik Gharbaoui

3-(1H-Tetrazol-5-yl)-1,4,5,6-tetrahydro-cyclopentapyrazole (MK-0354): A Partial Agonist of the Nicotinic Acid Receptor, G-Protein Coupled Receptor 109a, with Antilipolytic but No Vasodilatory Activity in Mice

The discovery and profiling of 3-(1H-tetrazol-5-yl)-1,4,5,6-tetrahydro-cyclopentapyrazole (5a, MK-0354), a partial agonist of GPR109a, is described. Compound 5a retained the plasma free fatty acid lowering effects in mice associated with GPR109a agonism, but did not induce vasodilation at the maximum feasible dose. Moreover, preadministration of 5a blocked the flushing effect induced by nicotinic acid but not that induced by PGD2. This profile made 5a a suitable candidate for further study for the treatment of dyslipidemia.

Discovery of fused bicyclic agonists of the orphan G-protein coupled receptor GPR119 with in vivo activity in rodent models of glucose control.

We herein outline the design of a new series of agonists of the pancreatic and GI-expressed orphan G-protein coupled receptor GPR119, a target that has been of significant recent interest in the field of metabolism, starting from our prototypical agonist AR231453. A number of key parameters were improved first by incorporation of a pyrazolopyrimidine core to create a new structural series and secondly by the introduction of a piperidine ether group capped with a carbamate. Chronic treatment with one compound from the series, 3k, showed for the first time that blood glucose and glycated hemoglobin (HbA1c) levels could be significantly reduced in Zucker Diabetic Fatty (ZDF) rats over several weeks of dosing. As a result of these and other data described here, 3k (APD668, JNJ-28630368) was the first compound with this mechanism of action to be progressed into clinical development for the treatment of diabetes.

Complementary asymmetric routes to (R)-2-(7-hydroxy-2,3-dihydro-1H-pyrrolo[1,2-a]indol-1-yl)acetate.

Two distinct and scalable enantioselective approaches to the tricyclic indole (R)-2-(7-hydroxy-2,3-dihydro-1H-pyrrolo[1,2-a]indol-1-yl)acetate, an important synthon for a preclinical S1P(1) receptor agonist, are reported. Route 1 employs a modified version of Smiths modular 2-substituted indole synthesis as the key transformation. Route 2 involves a highly enantioselective CuH-catalyzed 1,4-hydrosilylation as the stereodefining step. Both routes can be performed without chromatography to provide multigram quantities of the tricycle in ≥98% ee.

Discovery of APD334: Design of a Clinical Stage Functional Antagonist of the Sphingosine-1-phosphate-1 Receptor.

APD334 was discovered as part of our internal effort to identify potent, centrally available, functional antagonists of the S1P1 receptor for use as next generation therapeutics for treating multiple sclerosis (MS) and other autoimmune diseases. APD334 is a potent functional antagonist of S1P1 and has a favorable PK/PD profile, producing robust lymphocyte lowering at relatively low plasma concentrations in several preclinical species. This new agent was efficacious in a mouse experimental autoimmune encephalomyelitis (EAE) model of MS and a rat collagen induced arthritis (CIA) model and was found to have appreciable central exposure.

Fused tricyclic indoles as S1P1 agonists with robust efficacy in animal models of autoimmune disease

Two series of fused tricyclic indoles were identified as potent and selective S1P(1) agonists. In vivo these agonists produced a significant reduction in circulating lymphocytes which translated into robust efficacy in several rodent models of autoimmune disease. Importantly, these agonists were devoid of any activity at the S1P(3) receptor in vitro, and correspondingly did not produce S1P(3) mediated bradycardia in telemeterized rat.

(7-Benzyloxy-2,3-dihydro-1H-pyrrolo[1,2-a]indol-1-yl)acetic Acids as S1P1 Functional Antagonists

S1P1 is a validated target for treatment of autoimmune disease, and functional antagonists with superior safety and pharmacokinetic properties are being sought as second generation therapeutics. We describe the discovery and optimization of (7-benzyloxy-2,3-dihydro-1H-pyrrolo[1,2-a]indol-1-yl)acetic acids as potent, centrally available, direct acting S1P1 functional antagonists, with favorable pharmacokinetic and safety properties.

Discovery and optimization of 5-fluoro-4,6-dialkoxypyrimidine GPR119 agonists.

A series of 5-fluoro-4,6-dialkoxypyrimidine GPR119 modulators were discovered and optimized for in vitro agonist activity. A lead molecule was identified that has improved agonist efficacy relative to our clinical compound (APD597) and possesses reduced CYP2C9 inhibitory potential. This optimized lead was found to be efficacious in rodent models of glucose control both alone and in combination with a Dipeptidyl peptidase-4 (DPP-4) inhibitor.

Discovery of 2-(((1r,4r)-4-(((4-Chlorophenyl)(phenyl)carbamoyl)oxy)methyl)cyclohexyl)methoxy)acetate (Ralinepag): An Orally Active Prostacyclin Receptor Agonist for the Treatment of Pulmonary Arterial Hypertension

The design and synthesis of a new series of potent non-prostanoid IP receptor agonists that showed oral efficacy in the rat monocrotaline model of pulmonary arterial hypertension (PAH) are described. Detailed profiling of a number of analogues resulted in the identification of 5c (ralinepag) that has good selectivity in both binding and functional assays with respect to most members of the prostanoid receptor family and a more modest 30- to 50-fold selectivity over the EP3 receptor. In our hands, its potency and efficacy are comparable or superior to MRE269 (the active metabolite of the clinical compound NS-304) with respect to in vitro IP receptor dependent cAMP accumulation assays. 5c had an excellent PK profile across species. Enterohepatic recirculation most probably contributes to a concentration-time profile after oral administration in the cynomolgus monkey that showed a very low peak-to-trough ratio. Following the identification of an acceptable solid form, 5c was selected for further development for the treatment of PAH.