Abstract P6-18-21: Real world treatment patterns and outcomes of patients receiving palbociclib plus fulvestrant in the United States: Sub-groups analysis based on age, performance status and sites of metastases
Authors: Waller J , Mitra D , Taylor-Stokes G , Gibson K , Milligan G , Zhan L , Iyer S 
Published: May 2019

Background: Ibrance Real World Insights (IRIS) is a multi-country study aimed to describe the clinical characteristics and understand treatment patterns and clinical outcomes of patients receiving palbociclib plus fulvestrant in real world clinical practice. Previously the results on the overall population within the US have been communicated. The current analyses focus on subgroups stratified by age, performance status and visceral status.

Materials and methods: A retrospective chart review of HR+/HER2- ABC/MBC patients was conducted between June and October 2017. Physicians extracted data from patient medical records for HR+/HER2- ABC patients who received palbociclib plus fulvestrant following disease progression with endocrine based therapy for their advanced disease. Electronic case report forms collected data covering patient demographics, clinical characteristics, treatment history/patterns and clinical outcomes.Progression free rates and survival rates at 6 and 12 months were estimated via Kaplan-Meier analysis.

Results: Data for the US are reported here. In total, 65 physicians extracted data for 292 patients who had a mean follow up time of 7.4 months. Majority of the patients were &gt;65 years (54%), and had ECOG status of 0 (32%) or 1 (48%). Overall 224 (77%) patients had metastatic disease, of which 93 (42%) had visceral metastases. Across all sub-groups, majority of patients prescribed an initial palbociclib dose of 125mg did not require a change of dose while on treatment. The 6-month and 12-month progression free and survival rates across subgroups are presented in Table 1. Patients with a performance status of ECOG ≥ 2 had a slightly lower progression and survival rates at 6 and 12 months compared to those with a score &lt;1. Likewise, patients with visceral disease were observed to have slightly lower progression free and survival rates than others.

Table 1:Clinical Outcomes by Patient Sub-groups.Patient Sub-groups AgeECOGstatusVisceral Status Up to 65 n=158Over 65 n=1340 n=931 n=1392+ n=60Visceral Metastases n=93Non-visceral Metastases n=131Progression free survival rate at 6 months, %95.293.297.893.490.689.694.8Progression free survival rate at 12 months, %81.277.884.683.0-73.276.5Survival rate at 6 months, %98.096.3100.098.290.692.298.9Survival rate at 12 months, %90.085.197.695.1-80.892.7

Conclusions: The analysis indicates consistent trends in different clinical outcomes were observed with palbociclib plus fulvestrant across patients sub-groups based on age, performance status and visceral metastases.

Citation Format: Waller J, Mitra D, Taylor-Stokes G, Gibson K, Milligan G, Zhan L, Iyer S. Real world treatment patterns and outcomes of patients receiving palbociclib plus fulvestrant in the United States: Sub-groups analysis based on age, performance status and sites of metastases [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P6-18-21.