Treatment Patterns and Clinical Outcomes Among Patients Receiving Palbociclib Combinations for Hormone Receptor–Positive (HR+)/Human Epidermal Growth Factor Receptor 2–Negative (HER2−) Advanced/Metastatic Breast Cancer in the Arabian Gulf Region: A Retrospective Study (TREASURE Study)

Background Palbociclib, a cyclin‐dependent kinase 4/6 (CDK4/6) inhibitor, has been approved for advanced/metastatic breast cancer (ABC) treatment. However, real‐world data on its use in the Arabian Gulf region are limited. Methods The TREASURE study, a retrospective, multicenter study, evaluated patients with hormone receptor–positive/human epidermal growth factor receptor 2–negative (HR+/HER2−) ABC treated with palbociclib + endocrine therapy (ET) in the Arabian Gulf. Data were abstracted from the medical records of eligible patients from 7 selected sites across Arabian Gulf countries. The study evaluated patient demographics, clinical characteristics, treatment patterns, and clinical outcomes in those who initiated palbociclib + ET from April 2015 to September 2019. Results The study comprised 258 patients (median age: 53.7 years) who received palbociclib in the first‐line (1L) ( n = 93, 36.0%), second‐line (2L) ( n = 61, 23.6%), or third‐line and beyond (3L+) ( n = 30, 11.6%). Treatment regimens included palbociclib plus aromatase inhibitors ( n = 142, 55.0%) and palbociclib with fulvestrant ( n = 120, 46.5%). The starting dose of palbociclib was 125 mg for 228 patients (88.4%). The median duration of follow‐up was 16.8 months. Global median real‐world progression‐free survival (rwPFS) was 26.5 months (1L: 40.3, 2L: 18.5, 3L+: 17.2). The rwPFS rates at 12, 24, and 36 months were as follows: 1L—84.5%, 72.8%, and 58.4%; 2L—69.8%, 38.8%, and 16.2%; 3L+—80.0%, 42.3%, and 23.5%. Conclusion This study provides initial data on palbociclib′s real‐world treatment management and effectiveness in the Arabian Gulf region, with results consistent with those reported in clinical trials and other real‐world evidence studies. Larger studies with more patients are needed to further assess long‐term clinical outcomes in this population. Trial Registration: ClinicalTrials.gov identifier: NCT04916509