Selecting an anti-malarial clinical candidate from two potent dihydroisoquinolones

Malaria Journal

Karen L. White¹  Susan A. Charman¹  David M. Shackleford¹  Gloria Holbrook²  Fangyi Zhu²  Lei Yang²  Jared Hammill³  Yizhe Chen³  R. Kiplin Guy³  Burgess Freeman⁴  Jon C. Mirsalis⁵  Kathleen G. O’Loughlin⁵ 

[1] Centre for Drug Candidate Optimisation, Monash Institute of Pharmaceutical Sciences, Monash University, 3052, Parkville, VIC, Australia;Department of Chemical Biology and Therapeutics, St. Jude Children’s Research Hospital, 38105, Memphis, TN, USA;Department of Pharmaceutical Sciences, University of Kentucky College of Pharmacy, 40536, Lexington, KY, USA;Preclinical Pharmacokinetics Shared Resource, St. Jude Children’s Research Hospital, 38105, Memphis, TN, USA;Toxicology and Pharmacokinetics, SRI International, 94025, Menlo Park, CA, USA;

关键词: Candidate selection;    Physicochemical properties;    In vitro and in vivo metabolism;    Bioavailability;    Dose proportional exposure;   

DOI  :  10.1186/s12936-021-03617-1

来源: Springer

【 摘 要 】

BackgroundThe ongoing global malaria eradication campaign requires development of potent, safe, and cost-effective drugs lacking cross-resistance with existing chemotherapies. One critical step in drug development is selecting a suitable clinical candidate from late leads. The process used to select the clinical candidate SJ733 from two potent dihydroisoquinolone (DHIQ) late leads, SJ733 and SJ311, based on their physicochemical, pharmacokinetic (PK), and toxicity profiles is described.MethodsThe compounds were tested to define their physicochemical properties including kinetic and thermodynamic solubility, partition coefficient, permeability, ionization constant, and binding to plasma proteins. Metabolic stability was assessed in both microsomes and hepatocytes derived from mice, rats, dogs, and humans. Cytochrome P450 inhibition was assessed using recombinant human cytochrome enzymes. The pharmacokinetic profiles of single intravenous or oral doses were investigated in mice, rats, and dogs.ResultsAlthough both compounds displayed similar physicochemical properties, SJ733 was more permeable but metabolically less stable than SJ311 in vitro. Single dose PK studies of SJ733 in mice, rats, and dogs demonstrated appreciable oral bioavailability (60–100%), whereas SJ311 had lower oral bioavailability (mice 23%, rats 40%) and higher renal clearance (10–30 fold higher than SJ733 in rats and dogs), suggesting less favorable exposure in humans. SJ311 also displayed a narrower range of dose-proportional exposure, with plasma exposure flattening at doses above 200 mg/kg.ConclusionSJ733 was chosen as the candidate based on a more favorable dose proportionality of exposure and stronger expectation of the ability to justify a strong therapeutic index to regulators.

【 授权许可】

CC BY