Leaders in Pharmaceutical Business Intelligence (LPBI) Group

New glucokinase activator

Larry H. Bernstein, MD, FCAP, Curator

LPBI

RO-28-1675 for Type 2 Diabetes

by DR ANTHONY MELVIN CRASTO Ph.D

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RO-28-1675

• (2R)-3-Cyclopentyl-2-[4-(methanesulfonyl)phenyl]-N-(thiazol-2-yl)propionamide
• Ro 028-1675
• Ro 0281675
• Ro 28-1675

3-Cyclopentyl-2(R)-[4-(methylsulfonyl)phenyl]-N-(2-thiazolyl)propionamide

Glucokinase Activators

Ro 28-1675 (Ro 0281675) is a potent allosteric GK activator with a SC1.5 value of 0.24± 0.0019 uM.

Roche (Innovator)

Hoffmann La Roche

PHASE 1    Type 2  DIABETES,
IC50 value: 0.24± 0.0019 uM (SC1.5) [1]
Target: Glucokinase activator
The R stereoisomer Ro 28-1675 activated GK with a SC1.5 of 0.24 uM, while the S isomer did not activated GK up to 10 uM. Oral administration of Ro 28-1675 (50 mg/Kg) to male C57B1/6J mice caused a statistically significant reduction in fasting glucose levels and improvement in glucose tolerance relative to the vehicle treated animals [1].
Comparison of rat PK parameters indicated that Ro 28-1675 displayed lower clearance and higher oral bioavailability compared to 9a.

Following a single oral dose, Ro 28-1675 reduced fasting and postprandial glucose levels following an OGTT, was well tolerated, and displayed no adverse effects related to drug administration other than hypoglycemia at the maximum dose (400 mg).

RO-28-1675 as glucokinase activator.

Joseph Grimsby et al., of Roche have recently discovered activators of glucokinase that increase k_cat and decrease the S_0.5 for glucose, and these may offer a treatment for type II diabetes. Glucokinase (GK) plays a key role in whole-body glucose homeostasis by catalyzing the phosphorylation of glucose in cells that express this enzyme, such as pancreatic β cells and hepatocytes.

By screening of a library of 120,000 structurally diverse synthetic compounds, they found one small molecule that increased the enzymatic activity of GK. Chemical optimization of this initial molecule led to the synthesis of RO-28-0450 as a lead GK activator which is a class of antidiabetic agents that act as nonessential, mixed-type GK activators (GKAs) that increase the glucose affinity and maximum velocity (V_max) of GK. RO-28-0450 is a racemic compound.

Activation of GK was exquisitely sensitive to the chirality of the molecule: The R enantiomer, RO-28-1675, was found to be a potent GKA, whereas the S enantiomer, RO-28-1674, was inactive. RO-28-1675 also reversed the inhibitory action of the human glucokinase regulatory protein (GKRP). The activators binding in a glucokinase regulatory site originally was discovered in patients with persistent hyperinsulinemic hypoglycemi.

The result of RO-28-1675 as a potent small molecule GKA may shed light to the chemical biologists to devise strategy for developing activators. Thus for a success to this end we must focus on highly regulated enzymes, or cooperative enzymes such as glucokinase, where nature has provided binding sites that are designed to modulate catalysis.

SYNTHESIS

Paper

Glucokinase (GK) is a glucose sensor that couples glucose metabolism to insulin release. The important role of GK in maintaining glucose homeostasis is illustrated in patients with GK mutations. In this publication, identification of the hit molecule 1 and its SAR development, which led to the discovery of potent allosteric GK activators 9a and21a, is described. Compound 21a (RO0281675) was used to validate the clinical relevance of targeting GK to treat type 2 diabetes.

Flash chromatography (Merck Silica gel 60, 70-230 mesh, 9/1, 3/1, and then 11/9 hexanes/ethyl acetate) afforded (2R)-3-cyclopentyl-2-(4-methanesulfonylphenyl)-N-thiazol-2-yl-propionamide (2.10 g, 74%) as a white foam.   ….

PATENT

WO 2000058293

http://www.google.com/patents/WO2000058293A2?cl=en

Discovery, Structure−Activity Relationships, Pharmacokinetics, and Efficacy of Glucokinase Activator (2R)-3-Cyclopentyl-2-(4-methanesulfonylphenyl)-N-thiazol-2-yl-propionamide (RO0281675)