Background

Palbociclib is used to treat HR+/HER2− ABC with an aromatase inhibitor as first line of therapy (1LOT) or with fulvestrant in pts whose disease progressed on endocrine therapy. Limited information exists on comorbidities’ impact on rw clinical outcomes in these pts.

Methods

POLARIS is a prospective observational study of pts with HR+/HER2− ABC receiving palbociclib in clinical practice in the US and Canada. Rw progression-free survival (rwPFS) and overall survival (OS) for pts with clinically relevant comorbidities and by Charlson Comorbidity Index (CCI) score were descriptively summarized.

Results

1250 pts were enrolled (median age 64 y; 99% female; 27% de novo metastatic diagnosis; 32% bone-only; 40% visceral metastases). Of these, 908 (73%) received palbociclib as 1LOT and 342 (27%) as ≥ 2LOT. Pts had a median (range) of 2 (0–9) comorbidities; 5% had 0, 56% had 1–2, 32% had 3–4, and 7% had >4. Median OS (months; 95% CI) for pts with CCI scores of 0, 1–2, and 3+ were 48.8 (37.3–NE), NR (43.0–NE), and 34.3 (29.1–44.1) in 1LOT and 39.5 (30.6–50.5), 35.2 (26.5–41.6), and 31.6 (20.9–45.2) in ≥ 2LOT, respectively. Median rwPFS for CCI scores and certain comorbidities are shown (Table).

Conclusions

Pts with HR+/HER2− ABC receiving palbociclib and CCI scores 0 and 1–2 had similar rwPFS and OS regardless of LOT. Pts with CCI score 3+ had shorter rwPFS and OS in the 1LOT, and similar rwPFS but shorter OS in the ≥ 2LOT than pts with score 0–2. Pts with cardiac disorders in the 1LOT and blood and lymphatic disorders in the ≥ 2LOT had shorter rwPFS, while other subgroups achieved generally comparable clinical outcomes. Understanding potential impact of comorbidities on clinical outcome in the rw is important for treatment decision-making. Larger rw studies may be needed to further assess the true impact of these comorbidities. Table: 373P

rwPFS in pts with HR+/HER2− ABC by comorbidities and LOT

Clinical trial identification

NCT03280303.

Editorial acknowledgement

Medical writing support, conducted in accordance with Good Publication Practice (GPP3) and the International Committee of Medical Journal Editors (ICMJE) guidelines, was provided by Heather Caballes, PhD, of Oxford PharmaGenesis Inc., Newtown, PA, USA, with funding provided by Pfizer Inc., USA.

Legal entity responsible for the study

Pfizer Inc.

Funding

Pfizer Inc.

Disclosure

D. Tripathy: Financial Interests, Personal, Advisory Board, Serving on Steering Committee for TrialsEducational Lectures: Novartis; Financial Interests, Personal, Advisory Board, Steering Committee for and ongoing trial: Pfizer; Financial Interests, Personal, Advisory Board, Advisory council for design and interpretation of trials: GSK; Financial Interests, Personal, Invited Speaker, Educational Lectures: AstraZeneca; Financial Interests, Personal, Advisory Board, To discuss and interpret clinical trial data: Immunomedics; Financial Interests, Personal, Advisory Board, Advice on clinical trial design: OncoPep; Financial Interests, Personal, Invited Speaker, Lecture on gene profiling: Exact Sciences; Financial Interests, Personal, Advisory Board, Consulting: Sermonix; Financial Interests, Personal, Advisory Board, Consultant: Personalis, Puma Biotechnology, Gilead; Financial Interests, Institutional, Research Grant, Funding for laboratory experiments on the inhibition of CXCR4 in breast cancer cells: Polyphor; Financial Interests, Institutional, Invited Speaker, Global PI on one trial and local PI on another trial: Novartis. J.L. Blum: Financial Interests, Personal, Advisory Role: Puma Biotechnology, Athenix, Inc., OncLIve, Biotheranostics, AstraZeneca, Immunomedics, Inc., Research to Practice, Sanofi, Pfizer, Tempus, TD2; Financial Interests, Personal, Speaker’s Bureau: Pfizer, Tempus. S. McCune: Financial Interests, Personal, Speaker’s Bureau: BMS; Non-Financial Interests, Institutional, Principal Investigator: BMS, Merck, Roche/Genentech. Y. Wang: Financial Interests, Personal and Institutional, Full or part-time Employment: Pfizer; Financial Interests, Personal, Stocks/Shares: Pfizer. M.Z. Montelongo: Financial Interests, Personal and Institutional, Full or part-time Employment: ICON plc; Financial Interests, Personal and Institutional, Sponsor/Funding: Pfizer. Z. Zhang, E. Gauthier: Financial Interests, Personal and Institutional, Full or part-time Employment: Pfizer; Financial Interests, Personal and Institutional, Stocks or ownership: Pfizer. G. Rocque: Financial Interests, Institutional, Research Grant: Genentech, Pfizer, Carevive; Financial Interests, Institutional, Advisory Role: Pfizer; Financial Interests, Personal, Advisory Role: Gilead, Flatiron. All other authors have declared no conflicts of interest.