FIRST-LINE CDK4/6 INHIBITOR USE IN METASTATIC BREAST CANCER: REAL-WORLD DATA FROM A RETROSPECTIVE US COHORT STUDY

Author(s)

Clara Chen, MS, PhD1, Anirban Ghosh, PGDBA2, Ravi Potluri, PGDM3;
1AstraZeneca, Oncology Outcomes Research, Gaithersburg, MD, USA, 2Putnam Associates, Gurugram, India, 3Putnam Associates, New York, NY, USA
OBJECTIVES: The current standard-of-care first-line (1L) therapy for patients (pts) with hormone receptor-positive, human epidermal growth factor receptor 2-negative metastatic breast cancer (mBC) is a cyclin-dependent kinase 4/6 inhibitor (CDK4/6i) + aromatase inhibitor (AI). This retrospective, observational cohort study evaluated real-world data from two US Health Claims databases (KOMODO and OPTUM) to explore characteristics, treatment patterns, and outcomes of pts with mBC treated with 1L CDK4/6i + AI.
METHODS: Adults diagnosed with mBC between April 2017 and March 2024 (OPTUM) or September 2024 (KOMODO) who had received 1L CDK4/6i + AI and had >3 months of follow-up were included. Descriptive statistics were used to summarize demographics, baseline characteristics (including comorbidities), and treatment patterns. Time to treatment discontinuation (TTD) and time to next therapy (TTNT) were assessed using Kaplan-Meier methods.
RESULTS: The KOMODO and OPTUM cohorts comprised 6464 pts (median age 61 years; 64.3% <65 years) and 2133 pts (median age 69 years; 35.7% <65 years), respectively. Baseline comorbidities ≥20% in KOMODO/OPTUM pts, respectively, were: hypertension 44.2%/57.4%, cardiovascular disorders 19.3%/28.7%, diabetes 17.0%/26.2%, obesity 20.1%/22.1%, hypothyroidism 17.2%/23.3%, and chronic pulmonary disease 15.2%/20.1%. Between 2017 and 2024, for KOMODO/OPTUM, respectively, use of palbociclib decreased (88%/90% to 30%/38%), ribociclib increased (8%/6% to 35%/32%), and abemaciclib increased (4%/4% to 34%/31%); use of letrozole decreased (84%/81% to 60%/63%), whereas use of anastrozole increased (12%/15% to 36%/34%). For KOMODO and OPTUM, respectively, median TTD was 15.9 and 14.0 months, median TTNT was 17.6 and 15.5 months, and the 12-month discontinuation rate for 1L CDK4/6i + AI was 40.5% and 44.0%.
CONCLUSIONS: Data from two independent databases showed high levels of baseline comorbidities and confirmed a high rate of 1L CDK4/6i + AI discontinuation within a year (~40%). This highlights a need for novel regimens with prolonged disease control in 1L treatment of mBC.

Conference/Value in Health Info

2026-05, ISPOR 2026, Philadelphia, PA, USA

Value in Health, Volume 29, Issue S6

Code

RWD15

Topic

Real World Data & Information Systems

Topic Subcategory

Health & Insurance Records Systems

Disease

No Additional Disease & Conditions/Specialized Treatment Areas, SDC: Oncology

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