Palbociclib use with grade 3 neutropenia in hormone receptor-positive metastatic breast cancer

Ahrong Ham, Min Hwan Kim, Gun Min Kim, Jee Hung Kim, Jee Ye Kim, Hyung Seok Park, Seho Park, Young Up Cho, Byeong Woo Park, Seung Il Kim, Joohyuk Sohn

Research output: Contribution to journalArticlepeer-review

1 Citation (Scopus)


Purpose: Neutropenia is the most common toxicity of CDK4/6 inhibitors, causing frequent dose interruptions. However, CDK4/6 inhibitor-induced neutropenia shows a benign clinical course in contrast to that caused by chemotherapy. Here, we investigated the safety of a new dose scheme for palbociclib, which avoids dose delays or reductions due to afebrile grade 3 neutropenia. Methods: A consecutive cohort of ER(+)/HER2(−) advanced breast cancer patients who received palbociclib between 2017 and 2018 was analyzed. The patients were classified into Group 1 (patients who maintained palbociclib dose with afebrile grade 3 neutropenia), Group 2 (patients who experienced any dose modification with afebrile grade 3 neutropenia), and Group 3 (patients without afebrile grade 3 neutropenia). The primary endpoint was febrile neutropenia incidence; other toxicities were compared with those of the PALOMA-2 trial. Results: Among the 107 patients, 54.2%, 22.4%, and 23.4% were classified into Groups 1, 2, and 3, respectively. There was no febrile neutropenia in Groups 1 and 2 during palbociclib treatment. Group 1 showed higher incidence of thrombocytopenia (all-grade, 32.8%; grade 3–4, 8.6%) than Group 2 and the PALOMA-2 data, but there was no bleeding related to thrombocytopenia. Group 1 showed higher incidence of all-grade non-hematologic adverse events than Group 2; only one grade 3 non-hematologic toxicity was observed in Group 1. There were no treatment-related hospitalizations or deaths in Group 1. Conclusions: Thus, omitting palbociclib dose modification with afebrile grade 3 neutropenia is safe and tolerable without febrile neutropenia events. This scheme could be useful to avoid unnecessary reductions in palbociclib doses in future practice.

Original languageEnglish
Pages (from-to)107-116
Number of pages10
JournalBreast Cancer Research and Treatment
Issue number1
Publication statusPublished - 2020 Aug 1

Bibliographical note

Funding Information:
This research was supported by a grant from the Korea Health Technology R&D Project through the Korea Health Industry Development Institute (KHIDI), funded by the Ministry of Health & Welfare, Republic of Korea (Grant Number: HI19C0430).

Publisher Copyright:
© 2020, Springer Science+Business Media, LLC, part of Springer Nature.

All Science Journal Classification (ASJC) codes

  • Oncology
  • Cancer Research


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