Research is being conducted on the adverse event profiles associated with CDK4/6 inhibitors, which are used in the treatment of breast cancer. The safety of these inhibitors, as well as other related treatments such as selective estrogen receptor degraders, is being evaluated through various studies and real-world evidence. The findings suggest that while toxicities and adverse events can occur, some treatments may have manageable safety profiles, and optimizing their use is an area of ongoing study.