Please use this identifier to cite or link to this item: https://hdl.handle.net/2445/222387
Title: Extended follow-up of palbociclib with fulvestrant or letrozole for endocrine-sensitive, hormone receptor-positive/HER2-negative advanced breast cancer in the PARSIFAL trial
Author: Llombart Cussac, Antonio
Pérez García, José Manuel
Bellet Ezquerra, Meritxell
Dalenc, Florence
Gil Gil, Miguel
Ruiz Borrego, Manuel
Gavilá, Joaquín
Schmid, Peter
Zamora, Pilar
Wheatley, Duncan
Martínez de Dueñas, Eduardo
Amillano, Kepa
Di Cosimo, Serena
Antón, Antonio
Cottu, Paul-Henri
Shimizu, Eileen
Fernandez Pinto, Melissa
Sampayo Cordero, Miguel
Cortés, Javier
Keywords: Antihormones
Tractament adjuvant del càncer
Hormone antagonists
Adjuvant treatment of cancer
Issue Date: 17-Jun-2025
Publisher: Elsevier BV
Abstract: Background: Cyclin-dependent kinase 4 and 6 inhibitors (CDK4/6i) are the mainstay for hormone receptor (HR)positive/human epidermal growth factor receptor 2 (HER2)-negative advanced breast cancer (ABC). While the approved CDK4/6i have demonstrated significant improvements in progression-free survival (PFS), inconsistencies exist for overall survival (OS) benefits. Here, we report updated efficacy results from PARSIFAL, a randomized phase II study, that evaluated first-line palbociclib with either letrozole or fulvestrant in postmenopausal patients with endocrine-sensitive, HR-positive/HER2-negative ABC. Patients and methods: PARSIFAL-LONG was an international, multicenter, observational study that extended follow-up for patients included in PARSIFAL. The primary objective evaluated updated OS of palbociclib combined with endocrine therapy (fulvestrant or letrozole). Secondary objectives included updated investigator-assessed PFS and subsequent antineoplastic therapies. Exploratory endpoints included identification of new clinical prognostic markers for OS, specifically PFS duration. Results: A total of 419 of 486 (86.2%) patients from PARSIFAL were included. Median follow-up was 7.3 years (interquartile range 6.7-7.7 years). At data cut-off (8 January 2024), no differences in efficacy were observed between fulvestrant and letrozole for OS (hazard ratio 1.01, 95% confidence interval [CI], 0.80-1.28, P = 0.927) or PFS (hazard ratio 1.06,95% CI, 0.85-1.31, P = 0.612). Median OS for the overall PARSIFAL-LONG population was 61.8 months (95% CI 56.5-68.4 months), representing the highest OS reported to date for palbociclib and aligning with outcomes observed for other CDK4/6i in this setting. Median PFS was 32.6 months (95% CI 27.5-38.1 months). A total of 85 (20.3%) patients were defined as early progressors (PFS < 12 months). These patients had a shorter median post-progression OS than patients who remained progression free at 12 months (18.7 versus 27.4 months; hazard ratio 0.65, P = 0.004). Conclusions: Extended analysis from PARSIFAL confirmed no difference between fulvestrant and letrozole when combined with palbociclib for patients with endocrine-sensitive, HR-positive/HER2-negative ABC. Efficacy results were consistent with those reported in the pivotal first-line trials involving CDK4/6i. Progression within the first year on CDK4/6i may indicate a poorer prognosis.
Note: Reproducció del document publicat a: https://doi.org/10.1016/j.esmoop.2025.105309
It is part of: ESMO Open, 2025, vol. 10, num. 7
URI: https://hdl.handle.net/2445/222387
Related resource: https://doi.org/10.1016/j.esmoop.2025.105309
ISSN: 2059-7029
Appears in Collections:Articles publicats en revistes (Institut d'lnvestigació Biomèdica de Bellvitge (IDIBELL))

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