Real-world treatment patterns of subsequent therapy after palbociclib in patients with advanced breast cancer in Japan.

Abstract

PURPOSE:

The optimal treatment following endocrine therapy (ET) plus a cyclin-dependent kinase 4/6 inhibitor (CDK4/6i) has not been established. We aimed to investigate treatment patterns and time to treatment failure (TTF) of subsequent therapy after palbociclib in a Japanese real-world setting.

METHDS:

This retrospective observational study used de-identified data of patients with advanced breast cancer treated with palbociclib, using a nationwide claims database (April 2008 to June 2021). Measures included the type of subsequent therapies after palbociclib (endocrine-based therapy: ET alone, ET + CDK4/6i, and ET + mammalian target of rapamycin inhibitor [mTORi]; chemotherapy; chemotherapy + ET; and others) and their TTFs. The median TTF and 95% confidence interval (CI) were estimated using the Kaplan-Meier method.

RESULTS:

Of 1170 patients treated with palbociclib, 224 and 235 received subsequent therapies after first- and second-line palbociclib treatment, respectively. Among them, 60.7% and 52.8% were treated with endocrine-based therapies as first subsequent therapy, including ET + CDK4/6i (31.2% and 29.8%, respectively). The median TTF (95% CI) of ET alone, ET + CDK4/6i, and ET + mTORi as first subsequent therapy after first-line palbociclib were 4.4 (2.8-13.7), 10.9 (6.5-15.6), and 6.1 (5.1-7.2) months, respectively. No apparent relationship between the treatment duration of prior ET + palbociclib and subsequent abemaciclib was observed.

CONCLUSION:

This real-world study revealed that one-third of the patients received sequential CDK4/6i after ET + palbociclib, and treatment duration of ET + CDK4/6i following ET + palbociclib was the longest among the treatment options. Further data are awaited to determine whether ET + targeted therapy with CDK4/6i and mTORi provides acceptable treatment options following ET + palbociclib.

• Authors: Masataka Sawaki, Yasuaki Muramatsu, Kanae Togo, Hiroji Iwata
• Journal: Breast (Edinburgh, Scotland) (Breast) Vol. 70 Pg. 1-7 (Aug 2023) ISSN: 1532-3080 [Electronic] Netherlands
• PMID: 37267715 (Publication Type: Observational Study, Journal Article)
• Copyright: Copyright © 2023 The Authors. Published by Elsevier Ltd.. All rights reserved.

Chemical References

• palbociclib
• Pyridines
• Piperazines
• Cyclin-Dependent Kinase 4
• Protein Kinase Inhibitors
• Receptor, ErbB-2

Topics

• Humans
• Female
• Breast Neoplasms (etiology)
• Japan
• Pyridines (therapeutic use)
• Piperazines
• Antineoplastic Combined Chemotherapy Protocols (therapeutic use)
• Cyclin-Dependent Kinase 4
• Protein Kinase Inhibitors (therapeutic use)
• Receptor, ErbB-2