Addressing Central Nervous System (CNS) Penetration in Drug Discovery: Basics and Implications of the Evolving New Concept

Wiley - Tập 6 Số 11 - Trang 2030-2049 - 2009
Andreas Reichel1
1Research Pharmacokinetics, Global Drug Discovery, Bayer Schering Pharma, Müllerstrasse 178, D-13342 Berlin. [email protected]

Tóm tắt

AbstractDespite enormous efforts, achieving a safe and efficacious concentration profile in the brain remains one of the big challenges in central nervous system (CNS) drug discovery and development. Although there are multiple reasons, many failures are due to underestimating the complexity of the brain, also in terms of pharmacokinetics (PK).To this day, PK support of CNS drug discovery heavily relies on improving the blood–brain barrier (BBB) permeability in vitro and/or the brain/plasma ratio (Kp) in vivo, even though neither parameter can be reliably linked to pharmacodynamic (PD) and efficacy readouts. While increasing BBB permeability may shorten the onset of drug action, an increase in the total amount in brain may not necessarily increase the relevant drug concentration at the pharmacological target. Since the traditional Kp ratio is based on a crude homogenization of brain tissue, it ignores the compartmentalization of the brain and an increase favors non‐specific binding to brain lipids rather than free drug levels.To better link exposure/PK to efficacy/PD and to delineate key parameters, an integrated approach to CNS drug discovery is emerging which distinguishes total from unbound brain concentrations. As the complex nature of the brain requires different compartments to be considered when trying to understand and improve new compounds, several complementary parameters need to be measured in vitro and in vivo, and integrated into a coherent model of brain penetration and distribution.The new paradigm thus concentrates on finding drug candidates with the right balance between free fraction in plasma and brain, and between rate and extent of CNS penetration. Integrating this data into a coherent model of CNS distribution which can be linked to efficacy will allow it to design compounds with an optimal mix in physicochemical, pharmacologic, and pharmacokinetic properties, ultimately mitigating the risk for failures in the clinic.

Từ khóa


Tài liệu tham khảo

10.1038/nrd2094

10.1016/j.drudis.2007.08.013

10.1016/S0006-8993(00)03269-8

10.1602/neurorx.2.4.671

10.1038/sj.clpt.6100479

10.1602/neurorx.2.1.3

10.2174/138920006775541525

10.1517/17460440902729405

10.1038/nrd2368

10.1021/jm000407e

Roberts S. A., 2003, Curr. Opin. Drug Discovery Dev., 6, 66

H. van de Waterbeemd B. Testa

10.1016/S1359-6446(03)02961-1

10.1080/00498250701570285

10.1517/17460441.1.6.595

10.1517/17460441.3.6.677

10.1124/jpet.107.130294

10.1007/s11095-007-9502-2

10.2174/156802609787521607

Begley D. J., 2003, Prog. Drug Res., 61, 39

10.1016/j.neuron.2008.01.003

10.1111/j.1651-2227.2003.tb00226.x

10.1602/neurorx.2.1.15

10.1016/S1474-4422(07)70326-5

10.1038/nrn1824

10.1016/j.neuint.2003.11.006

10.2174/138920008786485182

10.1038/sj.bjp.0702873

Bickel U., 1996, J. Pharmacol. Exp. Ther., 278, 107

10.1038/sj.bjp.0704406

10.1016/j.ejps.2004.09.009

Wu D., 1997, Drug Metab. Dispos., 26, 768

10.1016/0024-3205(87)90431-0

10.1124/dmd.106.012294

10.1124/jpet.107.119560

S. Nag

Smith Q. R., 2003, Methods Mol. Med., 89, 193

Reichel A., 2003, Methods Mol. Med., 89, 307

10.1016/j.tiv.2004.06.011

10.1124/jpet.102.039255

10.1016/j.ijpharm.2004.10.007

10.1124/jpet.107.121525

J. W. Polli J. E. Humphreys S. A. Wring T. C. Burnette K. D. Read A. Hersey D. Butina L. Bertolotti F. Pugnaghi C. S. Serabjit‐Singh

10.1124/dmd.107.017434

10.1016/j.addr.2004.07.011

10.2174/138920008783331077

10.1016/S0169-409X(00)00109-5

10.1124/dmd.104.001222

10.1124/dmd.108.024125

W. S. Snyder M. J. Cook E. S. Nasser L. R. Karhausen G. P. Howells I. H. Tipton

10.1124/dmd.105.007914

10.1124/dmd.107.015222

Fridén M., 2009, Drug Metab. Dispos.

10.1021/jm070375w

T. N. Tozer M. Rowland

10.1124/jpet.105.092916

M. Rowland T. N. Tozer

10.1023/A:1008192010023

10.1002/bdd.325

10.1124/dmd.108.022814

10.1208/aapsj070354

10.1097/ALN.0b013e318164cf9e

10.1124/jpet.104.079319

Liu X., 2005, Curr. Opin. Drug Discovery Dev., 8, 505

10.1124/dmd.104.001230

10.1016/j.euroneuro.2007.06.003

10.1038/clpt.2008.195

10.1021/jm060642i

10.1038/nrd1130

10.1080/00498250802499459

10.1007/s00228-006-0179-y

10.1124/dmd.108.024745

10.1038/sj.clpt.6100467

10.1111/j.1440-1681.2007.04649.x