Efficacy of Limited Dose Modifications for Palbociclib-Related Grade 3 Neutropenia in Hormone Receptor–Positive Metastatic Breast Cancer
- Author:
Seul-Gi KIM
1
;
Min Hwan KIM
;
Sejung PARK
;
Gun Min KIM
;
Jee Hung KIM
;
Jee Ye KIM
;
Hyung Seok PARK
;
Seho PARK
;
Byeong Woo PARK
;
Seung Il KIM
;
Jung Hwan JI
;
Joon JEONG
;
Kabsoo SHIN
;
Jieun LEE
;
Hyung-Don KIM
;
Kyung Hae JUNG
;
Joohyuk SOHN
Author Information
- Publication Type:Original Article
- From:Cancer Research and Treatment 2023;55(4):1198-1209
- CountryRepublic of Korea
- Language:English
-
Abstract:
Purpose:Frequent neutropenia hinders uninterrupted palbociclib treatment in patients with hormone receptor (HR)–positive breast cancer. We compared the efficacy outcomes in multicenter cohorts of patients with metastatic breast cancer (mBC) receiving palbociclib following conventional dose modification or limited modified schemes for afebrile grade 3 neutropenia.
Materials and Methods:Patients with HR-positive, human epidermal growth factor receptor 2–negative mBC (n=434) receiving palbociclib with letrozole as first-line therapy were analyzed and classified based on neutropenia grade and afebrile grade 3 neutropenia management as follows: group 1 (maintained palbociclib dose, limited scheme), group 2 (dose delay or reduction, conventional scheme), group 3 (no afebrile grade 3 neutropenia event), and group 4 (grade 4 neutropenia event). The primary and secondary endpoints were progression-free survival (PFS) between groups 1 and 2 and PFS, overall survival, and safety profiles among all groups.
Results:During follow-up (median 23.7 months), group 1 (2-year PFS, 67.9%) showed significantly longer PFS than did group 2 (2-year PFS, 55.3%; p=0.036), maintained across all subgroups, and upon adjustment of the factors. Febrile neutropenia occurred in one and two patients of group 1 and group 2, respectively, without mortality.
Conclusion:Limited dose modification for palbociclib-related grade 3 neutropenia may lead to longer PFS, without increasing toxicity, than the conventional dose scheme.
