Document Report Card
Basic Information
ID: ALA4385643
Journal: Bioorg Med Chem Lett
Title: Design of a brain-penetrant CDK4/6 inhibitor for glioblastoma.
Authors: Bronner SM, Merrick KA, Murray J, Salphati L, Moffat JG, Pang J, Sneeringer CJ, Dompe N, Cyr P, Purkey H, Boenig GL, Li J, Kolesnikov A, Larouche-Gauthier R, Lai KW, Shen X, Aubert-Nicol S, Chen YC, Cheong J, Crawford JJ, Hafner M, Haghshenas P, Jakalian A, Leclerc JP, Lim NK, O'Brien T, Plise EG, Shalan H, Sturino C, Wai J, Xiao Y, Yin J, Zhao L, Gould S, Olivero A, Heffron TP.
Abstract: CDK4 and CDK6 are kinases with similar sequences that regulate cell cycle progression and are validated targets in the treatment of cancer. Glioblastoma is characterized by a high frequency of CDKN2A/CCND2/CDK4/CDK6 pathway dysregulation, making dual inhibition of CDK4 and CDK6 an attractive therapeutic approach for this disease. Abemaciclib, ribociclib, and palbociclib are approved CDK4/6 inhibitors for the treatment of HR+/HER2- breast cancer, but these drugs are not expected to show strong activity in brain tumors due to poor blood brain barrier penetration. Herein, we report the identification of a brain-penetrant CDK4/6 inhibitor derived from a literature molecule with low molecular weight and topological polar surface area (MW = 285 and TPSA = 66 Å2), but lacking the CDK2/1 selectivity profile due to the absence of a basic amine. Removal of a hydrogen bond donor via cyclization of the pyrazole allowed for the introduction of basic and semi-basic amines, while maintaining in many cases efflux ratios reasonable for a CNS program. Ultimately, a basic spiroazetidine (cpKa = 8.8) was identified that afforded acceptable selectivity over anti-target CDK1 while maintaining brain-penetration in vivo (mouse Kp,uu = 0.20-0.59). To probe the potency and selectivity, our lead compound was evaluated in a panel of glioblastoma cell lines. Potency comparable to abemaciclib was observed in Rb-wild type lines U87MG, DBTRG-05MG, A172, and T98G, while Rb-deficient cell lines SF539 and M059J exhibited a lack of sensitivity.
CiteXplore: 31307887