title: The role of chromatographic and chiroptical spectroscopic techniques and methodologies in support of drug discovery for atropisomeric drug inhibitors of Bruton's tyrosine kinase.
abstract: Atropisomers are stereoisomers resulting from hindered bond rotation. From synthesis of pure atropisomers, characterization of their interconversion thermodynamics to investigation of biological stereoselectivity, the evaluation of drug candidates subject to atropisomerism creates special challenges and can be complicated in both early drug discovery and later drug development. In this paper, we demonstrate an array of analytical techniques and systematic approaches to study the atropisomerism of drug molecules to meet these challenges. Using a case study of Bruton's tyrosine kinase (BTK) inhibitor drug candidates at Bristol-Myers Squibb, we present the analytical strategies and methodologies used during drug discovery including the detection of atropisomers, the determination of their relative composition, the identification of relative chirality, the isolation of individual atropisomers, the evaluation of interconversion kinetics, and the characterization of chiral stability in the solid state and in solution. In vivo and in vitro stereo-stability and stereo-selectivity were investigated as well as the pharmacological significance of any changes in atropisomer ratios. Techniques applied in these studies include analytical and preparative enantioselective supercritical fluid chromatography (SFC), enantioselective high performance liquid chromatography (HPLC), circular dichroism (CD), and mass spectrometry (MS). Our experience illustrates how atropisomerism can be a very complicated issue in drug discovery and why a thorough understanding of this phenomenon is necessary to provide guidance for pharmaceutical development. Analytical techniques and methodologies facilitate key decisions during the discovery of atropisomeric drug candidates by characterizing time-dependent physicochemical properties that can have significant biological implications and relevance to pharmaceutical development plans.
authors.affiliation: Bristol-Myers Squibb Research and Development, P.O. Box 4000, Princeton, NJ 08543, United States. Electronic address: jun.dai@bms.com.
authors.forename: Jun
authors.initials: J
authors.lastname: Dai
authors.affiliation: Bristol-Myers Squibb Research and Development, P.O. Box 4000, Princeton, NJ 08543, United States.
authors.forename: Chunlei
authors.initials: C
authors.lastname: Wang
authors.affiliation: Bristol-Myers Squibb Research and Development, P.O. Box 4000, Princeton, NJ 08543, United States.
authors.forename: Sarah C
authors.initials: SC
authors.lastname: Traeger
authors.affiliation: Bristol-Myers Squibb Research and Development, P.O. Box 4000, Princeton, NJ 08543, United States.
authors.forename: Lorell
authors.initials: L
authors.lastname: Discenza
authors.affiliation: Bristol-Myers Squibb Research and Development, P.O. Box 4000, Princeton, NJ 08543, United States.
authors.forename: Mary T
authors.initials: MT
authors.lastname: Obermeier
authors.affiliation: Bristol-Myers Squibb Research and Development, P.O. Box 4000, Princeton, NJ 08543, United States.
authors.forename: Adrienne A
authors.initials: AA
authors.lastname: Tymiak
authors.affiliation: Bristol-Myers Squibb Research and Development, P.O. Box 4000, Princeton, NJ 08543, United States.
authors.forename: Yingru
authors.initials: Y
authors.lastname: Zhang
mesh_terms: D000077329:Agammaglobulinaemia Tyrosine Kinase; D002851:Chromatography, High Pressure Liquid; D025924:Chromatography, Supercritical Fluid; D002942:Circular Dichroism; D055808:Drug Discovery / Q000295:instrumentation / Q000379:methods*; D007700:Kinetics; D013058:Mass Spectrometry; D011505:Protein-Tyrosine Kinases / Q000037:antagonists & inhibitors*; D013237:Stereoisomerism; D013816:Thermodynamics
chemical_list: D011505:Protein-Tyrosine Kinases; D000077329:Agammaglobulinaemia Tyrosine Kinase
keywords: Atropisomer; Bruton’s tyrosine kinase; Chiral separation; Circular dichroism; Drug discovery; Interconversion