Demographic Characteristics and Treatment Patterns Among Patients Receiving Palbociclib for HR+/HER2− Advanced Breast Cancer: A Nationwide Real-World Experience

BACKGROUND: This nationwide retrospective study reports data on the real-world use of the selective cyclin-dependent kinase 4 and 6 (CDK4/6) inhibitor palbociclib in a large population of advanced breast cancer (ABC) patients during a 2-year period in Hungary. METHODS: All patients with ABC who received palbociclib between May 1, 2017 and June 30, 2019 were included in the analysis. Patient demographic and clinical characteristics, disease-related factors and treatment patterns were examined during the early access program and in the regular reimbursement period. RESULTS: Altogether, 962 patients were included (mean age: 60.6 years). A total of 399 patients (41%) were treated with palbociclib plus aromatase inhibitors (P+AI), and 563 patients (59%) received palbociclib and fulvestrant (P+F). The most commonly prescribed AI was letrozole (n=359; 90%). Of those with metastatic disease (n=733; 76%), 241 patients (33%) had visceral metastases and 449 (61%) had bone-only disease. The majority of patients (79%) received palbociclib as first- or second-line therapy for ABC. The starting dose of palbociclib was 125 mg in 98% of patients; dose reductions were required in 32% of patients receiving P+AI and 31% of those treated with P+F. At the time of data collection, palbociclib therapy was ongoing in 270 patients (68%) in the P+AI group and 245 patients (44%) in the P+F group. CONCLUSIONS: This nationwide analysis is the first to provide insights into the real-world use of palbociclib in a large patient population from a Central-Eastern European country. The findings confirm the good tolerability of palbociclib with similar dose reduction rates to those reported from registration trials.