D. Oubre (Hammond, LA, United States of America)

Ponchartrain Cancer Center

Author Of 1 Presentation

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106P - Palbociclib (PAL) in Male Patients (pts) With Hormone Receptor-Positive/Human Epidermal Growth Factor Receptor 2-Negative (HR+/HER2-) Advanced Breast Cancer (ABC): Pt Characteristics and Treatment (Tx) Patterns From the POLARIS Study

Abstract

Background

The prevalence of male breast cancer is <1% of all breast cancer cases, limiting the ability to conduct randomized clinical studies in this population. PAL plus an aromatase inhibitor or fulvestrant (FUL) is approved for the Tx of HR+/HER2– ABC in men. This analysis describes real-world pt characteristics and PAL use in male pts enrolled in the POLARIS study.

Methods

POLARIS is an ongoing, prospective, real-world, noninterventional study in pts with HR+/HER2‒ ABC receiving PAL with a targeted enrollment of 1500 pts from ∼110 sites in the United States and Canada. Baseline demographics, clinical characteristics, and Tx patterns were descriptively analyzed in men with HR+/HER2– ABC using pt data collected from medical charts and physician surveys.

Results

A total of 15 men were enrolled at the data cutoff of December 17, 2020; median age was 66 years, 60.0% of pts had recurrent disease, 40.0% had de novo metastatic disease, and 46.7% had visceral disease (Table). PAL plus endocrine therapy (ET) was received as first-line (1L) therapy by 9 pts (60.0%), second-line (2L) therapy by 4 pts (26.7%), and 2L+ therapy by 2 pts (13.3%). Among all pts, 4 initiated PAL with letrozole, 3 with anastrozole, and 7 with FUL; 1 pt did not receive ET during cycle 1 but initiated FUL during cycle 2. PAL was initiated at 125 mg in 13 pts (86.7%) and 100 mg in 2 pts (13.3%). One pt had a dose modification (interruption due to pt decision).

Variable n (%) (N=15)
Age, y
Median (range) 66 (43–82)
Race
White 14 (93.3)
Black or African American 1 (6.7)
Ethnicity
Not Hispanic/Latino 15 (100)
Stage of current diagnosis
Locally advanced (stage III) 1 (6.7)
Metastatic (stage IV) 14 (93.3)
Disposition of diagnosis
Recurrent from earlier stage (stages 0–III) 9 (60.0)
De novo (newly diagnosed stage IV at enrollment) 6 (40.0)
Sites of distant metastases at ABC diagnosis
Median (range) 2.5 (1.0–5.0)
Bone metastases at ABC diagnosis among pts with stage IV disease
Bone only 5 (41.7)
Bone + other sites 7 (58.3)
Visceral disease
Yes 7 (46.7)
No 8 (53.3)
PAL starting dose, mg
125 13 (86.7)
100 2 (13.3)

Conclusions

This is one of the first prospective trials to report pt characteristics and Tx patterns among male pts with HR+/HER2– ABC receiving PAL+ET. In this real-world population with a heavy disease burden, PAL was well tolerated with only 1 pt requiring dose modification. Most men received PAL+ET as 1L therapy and initiated PAL at the recommended dose of 125 mg. Further evaluation of Tx patterns in this population is warranted.

Clinical trial identification

Pfizer; NCT03280303.

Editorial acknowledgement

Editorial support was provided by Jill Shults, PhD, of ICON plc, and was funded by Pfizer Inc.

Legal entity responsible for the study

Pfizer Inc.

Funding

Pfizer, Inc.

Disclosure

J.L. Blum: Advisory/Consultancy: Pfizer Inc; Advisory/Consultancy: AstraZeneca; Advisory/Consultancy: Novartis; Advisory/Consultancy: Puma Biotechnology; Advisory/Consultancy: Immunogenetics Inc; Advisory/Consultancy: Research to Practice. C. Dicristo: Full/Part-time employment: Pfizer Inc. M. Karuturi: Advisory/Consultancy: Pfizer Inc. E. Jepsen: Full/Part-time employment, Oncology Specialist: Novant Health. Z. Zhang, Y. Wang: Shareholder/Stockholder/Stock options, Full/Part-time employment: Pfizer Inc. D. Tripathy: Advisory/Consultancy, Research grant/Funding (self): Novartis; Advisory/Consultancy, Research grant/Funding (self): Pfizer Inc. All other authors have declared no conflicts of interest.

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