Discovery, Optimization, and Evaluation of Selective CDK4/6 Inhibitors for the Treatment of Breast Cancer

Area of Science:

• Oncology
• Medicinal Chemistry
• Pharmacology

Background:

• Breast cancer is the most prevalent cancer in women globally.
• Selective cyclin-dependent kinase (CDK) 4/6 inhibitors are crucial in breast cancer therapy.
• There is an ongoing need for novel CDK4/6 inhibitors with improved safety and efficacy profiles.

Purpose of the Study:

• To identify and optimize selective inhibitors targeting CDK4/6 for breast cancer treatment.
• To evaluate the safety, pharmacokinetic properties, and in vivo efficacy of the optimized inhibitor.

Main Methods:

• Virtual screening was employed to identify a lead compound (8).
• Systematic structural optimization led to the development of compound 42.
• In vitro kinase selectivity profiling and in vivo efficacy studies in a breast cancer model were performed.

Main Results:

• Compound 42 demonstrated potent inhibition of CDK4/6 with high selectivity against 205 kinases.
• The inhibitor exhibited an excellent safety profile (LD50 > 5,000 mg/kg) and favorable pharmacokinetics (F% = 43%).
• Compound 42 effectively reduced breast cancer burden in vivo.

Conclusions:

• A highly selective CDK4/6 inhibitor (42) was successfully developed.
• This compound represents a promising candidate for further preclinical development in breast cancer.
• The findings support the potential of this novel inhibitor in advancing breast cancer therapy.