In an interview that took place at the European Society for Medical Oncology 2024 Congress in Barcelona, Spain, Timothy Yap, MBBS, PhD, medical oncologist, The University of Texas MD Anderson Cancer Center, Houston, Texas, discussed findings from the Phase 1b/2 dose-escalation study of PF-07220060 (CDK4-selective inhibitor) and PF-07104091 (CDK2-selective inhibitor) in HR+/HER2- metastatic breast cancer and advanced solid tumors. Overall, this combination led to promising antitumor activity in heavily pretreated patients, particularly among patients with ESR1 mutations. Neutropenia, nausea, and diarrhea were commonly reported adverse events. Dose expansion is ongoing.