Breast (Dec 2023)

Anti-hormonal maintenance treatment with the CDK4/6 inhibitor ribociclib after 1st line chemotherapy in hormone receptor positive / HER2 negative metastatic breast cancer: A phase II trial (AMICA)

  • Thomas Decker,
  • Kerstin Lüdtke-Heckenkamp,
  • Luidmila Melnichuk,
  • Nader Hirmas,
  • Kristina Lübbe,
  • Mark-Oliver Zahn,
  • Marcus Schmidt,
  • Carsten Denkert,
  • Ralf Lorenz,
  • Volkmar Müller,
  • Dirk-Michael Zahm,
  • Christoph Mundhenke,
  • Stefan Bauer,
  • Marc Thill,
  • Peter Seropian,
  • Natalie Filmann,
  • Sibylle Loibl

Journal volume & issue
Vol. 72
p. 103575

Abstract

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Purpose: This phase II study evaluated the impact of adding ribociclib to maintenance endocrine therapy (ET) treatment of physicians’ choice following the first palliative chemotherapy in pre- and post-menopausal women with hormone receptor positive (HR+)/human epidermal growth factor 2 negative (HER2-) metastatic breast cancer (mBC). Patients and methods: The initial randomized study design was later amended into a single-arm study, and all subsequent patients received ribociclib and ET. The primary end point was locally assessed progression-free survival (PFS). Secondary end points included overall survival (OS), clinical benefit rate (CBR), safety, compliance, and quality of life (QoL). Results: A total of 43 patients received ribociclib + ET and 10 patients received ET only. Median PFS was 12.4 months [95% CI 8.7–24.4] for patients who received ribociclib + ET and 4.75 months [95% CI 1.0–10.3] for those who received ET only. Median OS was not reached for patients who received ribociclib + ET, and 28 (65.1%) patients experienced clinical benefit [95% CI 49.1–79.0]. For patients who received ribociclib + ET, grade 3–4 hematological adverse events (AEs) occurred in 25 (58.1%) patients, and grade 3–4 non-hematological AEs occurred in 17 (39.5%) patients. During the study, 15 patients died – 14 of whom due to tumor-related reasons, and one patient due to pneumonia, which was not treatment-related. Conclusion: The results of the AMICA study show a promising efficacy and safety of maintenance treatment with ribociclib added to ET after at least stable disease following the first metastatic chemotherapy in patients with HR+/HER2-mBC. Trial registration: Anti-hormonal Therapy With Ribociclib in HR-positive/HER2- Negative Metastatic Breast Cancer (AMICA), NCT03555877, https://clinicaltrials.gov/ct2/show/NCT03555877.

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