Understanding palbociclib practice patterns in a real-world setting.

Abstract

200 Background: Real-world practice patterns often differ from treatment in clinical trials. We assessed real-world standard-of-care treatment with palbociclib (PAL) in the context of previously reported PALOMA trial results. Methods: POLARIS is a prospective, observational study of PAL in patients (pts) with hormone receptor–positive, human epidermal growth factor receptor 2–negative advanced breast cancer. Baseline demographics, clinical characteristics, initial treatment dose, dose modifications, dose delays, and adverse events (AEs) during the first 6 months (mo) of treatment were analyzed. Results: 412 pts enrolled at 92 US sites had at least 6 mo of PAL treatment; 73% received PAL in the first-line setting and 27% in second or later line. While a majority of pts received the recommended dose of 125 mg/d; 6% and 1% started at 100 mg and 75 mg, respectively. Physician-reported reasons for choosing a lower dose were: comorbidities (31%), pt age (21%), past treatment (10%), patient preference (3%), and other (34%). Selected pt and clinical characteristics, dosing, and treatment outcomes in POLARIS and in PALOMA-2 are shown in Table. Conclusions: In a real-world data set of 6 mo of PAL treatment, most pts started at the recommended dose, with tolerability and safety outcomes consistent with those reported in clinical trials. Differing populations, treatment patterns, and outcome reporting in real world vs trial settings underscore the need to study real-world practices and outcomes. Clinical trial information: NCT03280303 [Table: see text]