Sandro Boland

Design, Synthesis, and Biological Evaluation of Novel, Highly Active Soft ROCK Inhibitors

ROCK1 and ROCK2 play important roles in numerous cellular functions, including smooth muscle cell contraction, cell proliferation, adhesion, and migration. Consequently, ROCK inhibitors are of interest for treating multiple indications including cardiovascular diseases, inflammatory and autoimmune diseases, lung diseases, and eye diseases. However, systemic inhibition of ROCK is expected to result in significant side effects. Strategies allowing reduced systemic exposure are therefore of interest. In a continuing effort toward identification of ROCK inhibitors, we here report the design, synthesis, and evaluation of novel soft ROCK inhibitors displaying an ester function allowing their rapid inactivation in the systemic circulation. Those compounds display subnanomolar activity against ROCK and strong differences of functional activity between parent compounds and expected metabolites. The binding mode of a representative compound was determined experimentally in a single-crystal X-ray diffraction study. Enzymes responsible for inactivation of these compounds once they enter systemic circulation are also discussed.

Rho kinase inhibitors: a patent review (2014 - 2016).

ABSTRACT Introduction: The Rho-kinases (ROCK), ROCK1 and ROCK2, are potent, widespread biochemical modulators which have been extensively studied. Due to the involvement of ROCKs in multiple biological processes, ROCK inhibitors have pleiotropic actions and may be of relevance for a number of therapeutic applications. The drawback is however that their use might be limited by occurrence of side effects. Areas covered: Since the publication of the latest review in 2014, there have been significant advances in the field of ROCK inhibitors. In this paper we reviewed the patents published between September 2013 and September 2016. Recent novel molecules will be described. and progress from the compounds series described in the previous review as well as any new expected therapeutic uses for ROCK inhibitors that popped up in the last three years will be examined. Expert opinion: While a number of potential applications in human for ROCK inhibitors have been reported, very few molecules are currently available to patients. In addition to fasudil, ripasudil (K-115, Kowa) was only recently approved in Japan for the treatment of glaucoma (2014). Notwithstanding some failures and subsequent discontinuation, the Pipeline of preclinical and clinical ROCK inhibitors remains significant.

Design, synthesis and biological characterization of selective LIMK inhibitors.

Inhibitors of LIM kinases are considered of interest for several indications, including elevated intraocular pressure (IOP), cancer, or infection by HIV-1. LX-7101 (Lexicon Pharmaceuticals) was advanced to Phase-I clinical trials as an IOP-lowering agent for treatment of glaucoma. We here discuss the design, synthesis and evaluation of LIMK inhibitors based on a pyrrolopyrimidine scaffold, which represent close analogs of LX-7101. Exploration of structure-activity relationships revealed that many of such compounds, including LX-7101, cause potent inhibition of LIMK1 and LIMK2, and also ROCK2 and PKA. Molecular variations around the various structural elements of LX-7101 were attempted. Substitution on position 6 of the pyrrolopyrimidine scaffold led to the identification of LX-7101 analogs displaying good selectivity versus ROCK, PKA and Akt.

Novel Roflumilast analogs as soft PDE4 inhibitors

PDE4 inhibitors are of high interest for treatment of a wide range of inflammatory or autoimmune diseases. Their potential however has not yet been realized due to target-associated side effects, resulting in a low therapeutic window. We herein report the design, synthesis and evaluation of novel PDE4 inhibitors containing a γ-lactone structure. Such molecules are designed to undergo metabolic inactivation when entering circulation, thereby limiting systemic exposure and reducing the risk for side effects. The resulting inhibitors were highly active on both PDE4B1 and PDE4D2 and underwent rapid degradation in human plasma by paraoxonase 1. In contrast, their metabolites displayed markedly reduced permeability and/or on-target activity.

Kinase profiling in early stage drug discovery: sorting things out

Protein kinases represent one of the largest superfamilies of drugable targets and a major research area for both the pharmaceutical industry and academic groups. This has resulted in the emergence of numerous screening technologies and services dedicated to kinase profiling. In spite of this plentiful offering, the field is not without its own pitfalls, as the profusion of reported conditions and data can ultimately complicate interpretation of project results. Here, we discuss how kinase profiling was used in our early stage drug discovery efforts, from the perspective of a smaller biotech relying largely on assay outsourcing.

An allosteric binding site of the α7 nicotinic acetylcholine receptor revealed in a humanized acetylcholine-binding protein

Nicotinic acetylcholine receptors (nAChRs) belong to the family of pentameric ligand-gated ion channels and mediate fast excitatory transmission in the central and peripheral nervous systems. Among the different existing receptor subtypes, the homomeric α7 nAChR has attracted considerable attention because of its possible implication in several neurological and psychiatric disorders, including cognitive decline associated with Alzheimers disease or schizophrenia. Allosteric modulators of ligand-gated ion channels are of particular interest as therapeutic agents, as they modulate receptor activity without affecting normal fluctuations of synaptic neurotransmitter release. Here, we used X-ray crystallography and surface plasmon resonance spectroscopy of α7-acetylcholine–binding protein (AChBP), a humanized chimera of a snail AChBP, which has 71% sequence similarity with the extracellular ligand-binding domain of the human α7 nAChR, to investigate the structural determinants of allosteric modulation. We extended previous observations that an allosteric site located in the vestibule of the receptor offers an attractive target for receptor modulation. We introduced seven additional humanizing mutations in the vestibule-located binding site of AChBP to improve its suitability as a model for studying allosteric binding. Using a fragment-based screening approach, we uncovered an allosteric binding site located near the β8–β9 loop, which critically contributes to coupling ligand binding to channel opening in human α7 nAChR. This work expands our understanding of the topology of allosteric binding sites in AChBP and, by extrapolation, in the human α7 nAChR as determined by electrophysiology measurements. Our insights pave the way for drug design strategies targeting nAChRs involved in ion channel–mediated disorders.