Real-world treatment of patients with palbociclib for HR+/HER2-advanced/metastatic breast cancer: the Europe IRIS study.

To report the Europe Ibrance Real World Insights study findings. Physicians abstracted demographic/clinical characteristics, treatment and outcomes data for women with locally advanced breast cancer (ABC) or metastatic  breast cancer (MBC) receiving palbociclib + aromatase inhibitor (AI) or palbociclib + fulvestrant. Kaplan-Meier analysis estimated progression-free rates (PFRs) and survival rates (SRs). 238 physicians abstracted data for 1723 patients. For patients (>90%) initiating at 125 mg/day, dose was reduced in 18.9% of palbociclib + AI and 12.3% of palbociclib + fulvestrant patients. At 12 months, PFR for palbociclib + AI was 88.1%, and SR was 97.3%; PFR for palbociclib + fulvestrant was 79.8%, and SR was 97.5%. Low dose-reduction rates and favorable PFRs and SRs suggest that palbociclib + AI/fulvestrant is well tolerated and effective for ABC/MBC in real-world clinical practice.