Reducing safety-related drug attrition: the use of in vitro pharmacological profiling

Bowes, Joanne; Brown, Andrew J.; Hamon, Jacques; Jarolimek, Wolfgang; Sridhar, Arun; Waldron, Gareth; Whitebread, Steven

doi:10.1038/nrd3845

Cited by 631 publications

(660 citation statements)

References 94 publications

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“…While ethyl substitution (compare 15 with 11) gave no advantage, benzyl compound 16 improved PAK4 selectivity 15-fold. Addition of F (17) or CN (18) to the ortho position of the benzyl group gave a 4-fold PAK1 potency increase with improved selectivity against all antitarget kinases measured, including Src. Throughout the optimization process, cellular pPAK1 inhibition was measured in an MCF10A cell line.…”

Section: Acs Medicinal Chemistry Lettersmentioning

confidence: 99%

Optimization of Highly Kinase Selective Bis-anilino Pyrimidine PAK1 Inhibitors

McCoull

Hennessy

Blades

et al. 2016

ACS Med. Chem. Lett.

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Group I p21-activated kinase (PAK) inhibitors are indicated as important in cancer progression, but achieving high kinase selectivity has been challenging. A bis-anilino pyrimidine PAK1 inhibitor was identified and optimized through structurebased drug design to improve PAK1 potency and achieve high kinase selectivity, giving in vitro probe compound AZ13705339 (18). Reduction of lipophilicity to lower clearance afforded AZ13711265 (14) as an in vivo probe compound with oral exposure in mouse. Such probes will allow further investigation of PAK1 biology. KEYWORDS: PAK, LLE, kinase selectivity, probe, bis-anilino pyrimidine T he p21-activated kinases (PAKs) are a family of six serine/ threonine-specific intracellular protein kinases that are positioned at the intersection of multiple signaling pathways of importance in cancer progression. 1,2 The PAK family comprises two subgroups based on sequence homology: group I (PAKs 1−3) and group II (PAKs 4−6). Group I PAKs have high sequence identity in the kinase domain and possess an autoinhibitory domain, which is relieved by binding of the GTP-binding proteins Rac or Cdc42, while group II PAKs have lower kinase domain homology and are not activated by Rho GTPases. 3 Group I PAKs are overexpressed in a wide variety of cancers, and PAK1 is commonly overexpressed in breast tumors with poor prognosis. 4 In ovarian cancer cells characterized by PAK1 amplification, treatment with a PAK1 inhibitor decreased proliferation and migration. 5 In tumors characterized by neurofibromatosis type 2 (NF2) inactivation, group I PAKs have been shown to be hyperactivated. 6 Consequently, there is increasing interest in identifying potent and selective small molecule inhibitors of PAK1 for therapeutic use in tumors characterized by PAK activation. 7 There are relatively few chemotypes described in the literature for PAK1 inhibitors 8 and only pan-PAK inhibitor PF-3578309 9 progressed into clinical trials but is now stopped. Ourselves 10 and others 11,12 have recently disclosed PAK1 inhibitors but achieving high kinase selectivity with a chemotype amenable to achieving oral exposure has been challenging. Without high kinase selectivity it is difficult to discern whether PAK1 is driving efficacy; thus, new alternative chemotypes for selective PAK1 inhibition are required.Following a kinase-focused subset screen (120k compounds) of the AstraZeneca compound collection, bis-anilino pyrimidine 1 (Figure 1) was identified as a modestly potent PAK1 inhibitor (IC 50 = 100 nM) with 11-fold selectivity over PAK4 (Table 1).While selectivity within the group I PAKs was not expected, PAK4 was utilized to monitor selectivity against group II PAKs. Selectivity against some key kinase antitargets, KDR and FGFR1, 13 was modest. Since 1 originated from an EphB4 kinase project, 14 a member of the Src kinase family, high activity for Src kinase was expected. Src family kinase activity was of less concern to us but was monitored as a measure of overall kinase selectivity. A crystal structure of 1 bound...

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Section: Acs Medicinal Chemistry Lettersmentioning

confidence: 99%

Optimization of Highly Kinase Selective Bis-anilino Pyrimidine PAK1 Inhibitors

McCoull

Hennessy

Blades

et al. 2016

ACS Med. Chem. Lett.

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“…GABA A R has been identified not only as a major target for designing anti-anxiety and anesthetic drugs (2,44) but also as a recommended target for assessing potential side effects of drugs (4). Fig.…”

Section: Use Of Centrifugal Force To Accelerate Vesicle Fusion To Incmentioning

confidence: 99%

“…Owing to their crucial roles in regulating transmembrane signaling, ion channel proteins are major targets for drug design (1,2). There is a growing interest in the development of drug-screening platforms for ion channels because a wide range of ion channels have been identified not only as primary molecular targets in drug actions but also as major targets in drug-induced side effects (3,4). Recording ion-channel activities by measuring ion currents is an efficient method for investigating the functions of channels and screening for both beneficial and adverse effects of drug candidates (3).…”

Section: Introductionmentioning

confidence: 99%

Reconstitution of Human Ion Channels into Solvent-free Lipid Bilayers Enhanced by Centrifugal Forces

Hirano‐Iwata

Ishinari

Yoshida

et al. 2016

Biophysical Journal

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Artificially formed bilayer lipid membranes (BLMs) provide well-defined systems for functional analyses of various membrane proteins, including ion channels. However, difficulties associated with the integration of membrane proteins into BLMs limit the experimental efficiency and usefulness of such BLM reconstitution systems. Here, we report on the use of centrifugation to more efficiently reconstitute human ion channels in solvent-free BLMs. The method improves the probability of membrane fusion. Membrane vesicles containing the human ether-a-go-go-related gene (hERG) channel, the human cardiac sodium channel (Na v 1.5), and the human GABA A receptor (GABA A R) channel were formed, and the functional reconstitution of the channels into BLMs via vesicle fusion was investigated. Ion channel currents were recorded in 67% of the BLMs that were centrifuged with membrane vesicles under appropriate centrifugal conditions (14-55 Â g). The characteristic channel properties were retained for hERG, Na v 1.5, and GABA A R channels after centrifugal incorporation into the BLMs. A comparison of the centrifugal force with reported values for the fusion force revealed that a centrifugal enhancement in vesicle fusion was attained, not by accelerating the fusion process but by accelerating the delivery of membrane vesicles to the surface of the BLMs, which led to an increase in the number of membrane vesicles that were available for fusion. Our method for enhancing the probability of vesicle fusion promises to dramatically increase the experimental efficiency of BLM reconstitution systems, leading to the realization of a BLM-based, high-throughput platform for functional assays of various membrane proteins.

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“…Drug Discov. 11, 909-922 (2012)) 1 . Information on the potency of a drug for a given biological target can be used to determine structure-activity relationships, assess potential liability for off-target effects, and influence early clinical trial design, dose selection and patient monitoring.…”

mentioning

confidence: 99%

“…Although secondary pharmacology data are often included early in the drug submission process as part of a standard safety pharmacology screen 2 , there is variability in the timing, type, extent and format of secondary pharmacology data submitted to regulatory agencies 1 . This Correspondence addresses these issues by discussing the utility of and regulatory perspectives on in vitro secondary pharmacology data, how such data are used in the Center for Drug Evaluation and Research at the US Food and Drug Administration and when such data are usually submitted.…”

mentioning

confidence: 99%