Discovery of (4-Pyrazolyl)-2-aminopyrimidines as Potent and Selective Inhibitors of Cyclin-Dependent Kinase 2

Area of Science:

• Oncology
• Molecular Biology
• Medicinal Chemistry

Background:

• Cyclin-dependent kinase 2 (CDK2) is crucial for cell cycle regulation.
• Dysregulation of the CDK2/cyclin E1 pathway is implicated in various human cancers, driving tumor growth and proliferation.
• Previous attempts to develop selective CDK2 inhibitors faced challenges with off-target toxicity.

Purpose of the Study:

• To discover and develop novel, selective CDK2 inhibitors for potential cancer therapy.
• To identify a potent inhibitor with a favorable selectivity profile against other CDK isoforms.

Main Methods:

• Structure-activity relationship (SAR) studies were conducted on (4-pyrazolyl)-2-aminopyrimidines.
• In vitro kinase assays were used to determine inhibitory potency and selectivity.
• Compound 17 was evaluated in CCNE1-amplified mouse models.

Main Results:

• A novel class of (4-pyrazolyl)-2-aminopyrimidines was identified as potent CDK2 inhibitors.
• Compound 17 exhibited high selectivity for CDK2 over CDKs 1, 4, 6, 7, and 9, with an IC50 of 0.29 nM.
• Pharmacodynamic inhibition of CDK2, evidenced by reduced Rb phosphorylation, and significant antitumor activity were observed in vivo.

Conclusions:

• Compound 17 represents a highly selective and potent CDK2 inhibitor.
• This discovery offers a promising therapeutic strategy for cancers driven by CDK2/cyclin E1 dysregulation.
• Further development of compound 17 warrants investigation for clinical applications in oncology.