David B. Rawlins

Novel Class of LIM-Kinase 2 Inhibitors for the Treatment of Ocular Hypertension and Associated Glaucoma

The discovery of a pyrrolopyrimidine class of LIM-kinase 2 (LIMK2) inhibitors is reported. These LIMK2 inhibitors show good potency in enzymatic and cellular assays and good selectivity against ROCK. After topical dosing to the eye in a steroid induced mouse model of ocular hypertension, the compounds reduce intraocular pressure to baseline levels. The compounds also increase outflow facility in a pig eye perfusion assay. These results suggest LIMK2 may be an effective target for treating ocular hypertension and associated glaucoma.

Novel l-Xylose Derivatives as Selective Sodium-Dependent Glucose Cotransporter 2 (SGLT2) Inhibitors for the Treatment of Type 2 Diabetes

The prevalence of diabetes throughout the world continues to increase and has become a major health issue. Recently there have been several reports of inhibitors directed toward the sodium-dependent glucose cotransporter 2 (SGLT2) as a method of maintaining glucose homeostasis in diabetic patients. Herein we report the discovery of the novel O-xyloside 7c that inhibits SGLT2 in vitro and urinary glucose reabsorption in vivo.

1H-Pyrazolo[3,4-b]pyridine inhibitors of cyclin-dependent kinases: highly potent 2,6-Difluorophenacyl analogues

Structure-activity studies of 1H-pyrazolo[3,4-b]pyridine 1 have resulted in the discovery of potent CDK1/CDK2 selective inhibitor 21h, BMS-265246 (CDK1/cycB IC(50)=6 nM, CDK2/cycE IC(50)=9 nM). The 2,6-difluorophenyl substitution was critical for potent inhibitory activity. A solid state structure of 21j, a close di-fluoro analogue, bound to CDK2 shows the inhibitor resides coincident with the ATP purine binding site and forms important H-bonds with Leu83 on the protein backbone.

1H-Pyrazolo[3,4-b]pyridine Inhibitors of Cyclin-Dependent Kinases

1H-Pyrazolo[3,4-b]pyridine 3 (SQ-67563) has been shown to be a potent, selective inhibitor of CDK1/CDK2 in vitro. In cells 3 acts as a cytotoxic agent with the ability to block cell cycle progression and/or induce apoptosis. The solid state structure of 3 bound to CDK2 shows 3 resides coincident with the ATP purine binding site and forms important H-bonding interactions with Leu83 on the protein backbone.

Discovery and Development of LX7101, a Dual LIM-Kinase and ROCK Inhibitor for the Treatment of Glaucoma.

The structure of LX7101, a dual LIM-kinase and ROCK inhibitor for the treatment of ocular hypertension and associated glaucoma, is disclosed. Previously reported LIM kinase inhibitors suffered from poor aqueous stability due to solvolysis of the central urea. Replacement of the urea with a hindered amide resulted in aqueous stable compounds, and addition of solubilizing groups resulted in a set of compounds with good properties for topical dosing in the eye and good efficacy in a mouse model of ocular hypertension. LX7101 was selected as a clinical candidate from this group based on superior efficacy in lowering intraocular pressure and a good safety profile. LX7101 completed IND enabling studies and was tested in a Phase 1 clinical trial in glaucoma patients, where it showed efficacy in lowering intraocular pressure.

Discovery of a Type III Inhibitor of LIM Kinase 2 That Binds in a DFG-Out Conformation.

The first allosteric, type III inhibitor of LIM-kinase 2 (LIMK2) is reported. A series of molecules that feature both an N-phenylsulfonamide and tertiary amide were not only very potent at LIMK2 but also were extremely selective against a panel of other kinases. Enzymatic kinetic studies showed these molecules to be noncompetitive with ATP, suggesting allosteric inhibition. X-ray crystallography confirmed that these sulfonamides are a rare example of a type III kinase inhibitor that binds away from the highly conserved hinge region and instead resides in the hydrophobic pocket formed in the DFG-out conformation of the kinase, thus accounting for the high level of selectivity observed.

Discovery of LX2761, a Sodium-Dependent Glucose Cotransporter 1 (SGLT1) Inhibitor Restricted to the Intestinal Lumen, for the Treatment of Diabetes

The increasing number of people afflicted with diabetes throughout the world is a major health issue. Inhibitors of the sodium-dependent glucose cotransporters (SGLT) have appeared as viable therapeutics to control blood glucose levels in diabetic patents. Herein we report the discovery of LX2761, a locally acting SGLT1 inhibitor that is highly potent in vitro and delays intestinal glucose absorption in vivo to improve glycemic control.