Results of the PARSIFAL-LONG study investigating endocrine-sensitive hormone receptor-positive/HER2-negative (HR+/HER2-) advanced breast cancer demonstrate the efficacy of two combination therapies: palbociclib (Ibrance; Pfizer) and letrozole (Femara; Novartis). Proven. Palbociclib is used in combination with fulvestrant (Faslodex; Hikma) as a first-line treatment for metastatic breast cancer. The study found no significant differences in progression-free survival (PFS) and overall survival (OS) between the two treatments. The study results were presented at the 2023 San Antonio Breast Cancer Symposium (SABCS) in Texas.
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PARSIFAL-LONG is a follow-up study to PARSIFAL that investigated the optimal endocrine agents (letrozole and fulvestrant) in combination with palbociclib in patients with first-line, untreated, endocrine-sensitive HR+/HER2 advanced breast cancer. . This trial failed to demonstrate an improvement in PGS with palbociclib and fulvestrant over palbociclib and letrozole with a median follow-up of 2.7 years. OS data were immature at the time of data cutoff.
PARSIFAL-LONG is an extended efficacy evaluation of the PARSIFAL study with a median follow-up of 5 years. The primary objectives were to evaluate OS, prolonged PFS, OS of the combination group, and efficacy after treatment progression between the palbociclib + letrozole and palbociclib + fulvestrant groups. A total of 389 patients with HR+/HER2- advanced breast cancer were enrolled, representing 80.5% of all patients initially enrolled in PARSIFAL. Approximately 22.1% (n = 86) of patients progressed within 1 year of treatment, with a median OS of 24 months. The remaining 77.9% of patients (n = 303) were progression-free at 12 months on palbociclib-based regimens, demonstrating an improved median OS of 81.5 months.
Patients who experienced progression during the 5-year follow-up were evaluated based on duration of progression. OS for patients who progressed within 1 year was 18 months, compared with 18 months for patients who progressed after 1 year. 27 months.
This study found no significant difference in PFS and OS when palbociclib was combined with letrozole or fulvestrant (median follow-up 59.7 months). With no difference between groups, the total median PFS between groups was 33.2 months (95% CI, 27.7 to 39.5 months) and the total median OS was 65.4 months (95% CI, 57.8 to 72.0 months). month).
Antonio Lombard Cusac, MD, Chief of Oncology at Arnau de Vilanova Hospital and Medical Senior Scientific Officer at MEDSIR, said: “When we combine the two treatment arms, our OS and PFS values are comparable to those of others. “It's equally consistent with CDK4/6 inhibitors.” when announcing the results. “Early progression with palbociclib-based regimens serves as a powerful early clinical biomarker for survival.”
reference
Messil.Long-term PARSIFAL trial shows no clear difference in heart rate between palbociclib-letrozole and palbociclib-fulvestrant over 5 years[+]/HER2[-] Advanced breast cancer. news release. December 6, 2023. Accessed December 7, 2023. https://www.prnewswire.com/news-releases/prolonged-parsifal-study-shows-no-distinct-differences-at-5-years-between-palbociclib-letrozole-and-palbociclib-fulvestrant-in-hrher2- -Advanced Breast Cancer-302007622.html
