201. Potent Cell-Cycle Inhibition and Upregulation of Immune Response with Abemaciclib and Anastrozole in neoMONARCH, Phase II Neoadjuvant Study in HR + /HER2 - Breast Cancer.
- Author
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Hurvitz SA, Martin M, Press MF, Chan D, Fernandez-Abad M, Petru E, Rostorfer R, Guarneri V, Huang CS, Barriga S, Wijayawardana S, Brahmachary M, Ebert PJ, Hossain A, Liu J, Abel A, Aggarwal A, Jansen VM, and Slamon DJ
- Subjects
- Adult, Aged, Aged, 80 and over, Aminopyridines administration & dosage, Anastrozole administration & dosage, Benzimidazoles administration & dosage, Breast Neoplasms immunology, Breast Neoplasms pathology, Cyclin-Dependent Kinase 4 antagonists & inhibitors, Cyclin-Dependent Kinase 6 antagonists & inhibitors, Estrogen Receptor alpha metabolism, Female, Humans, Middle Aged, Neoplasm Staging, Patient Safety, Postmenopause physiology, Receptor, ErbB-2 metabolism, Receptors, Progesterone metabolism, Treatment Outcome, Adaptive Immunity drug effects, Antineoplastic Combined Chemotherapy Protocols therapeutic use, Breast Neoplasms drug therapy, Cell Cycle Checkpoints, Neoadjuvant Therapy methods
- Abstract
Purpose: neoMONARCH assessed the biological effects of abemaciclib in combination with anastrozole in the neoadjuvant setting., Patients and Methods: Postmenopausal women with stage I-IIIB HR
+ /HER2- breast cancer were randomized to a 2-week lead-in of abemaciclib, anastrozole, or abemaciclib plus anastrozole followed by 14 weeks of the combination. The primary objective evaluated change in Ki67 from baseline to 2 weeks of treatment. Additional objectives included clinical, radiologic, and pathologic responses, safety, as well as gene expression changes related to cell proliferation and immune response., Results: Abemaciclib, alone or in combination with anastrozole, achieved a significant decrease in Ki67 expression and led to potent cell-cycle arrest after 2 weeks of treatment compared with anastrozole alone. More patients in the abemaciclib-containing arms versus anastrozole alone achieved complete cell-cycle arrest (58%/68% vs. 14%, P < 0.001). At the end of treatment, following 2 weeks lead-in and 14 weeks of combination therapy, 46% of intent-to-treat patients achieved a radiologic response, with pathologic complete response observed in 4%. The most common all-grade adverse events were diarrhea (62%), constipation (44%), and nausea (42%). Abemaciclib, anastrozole, and the combination inhibited cell-cycle processes and estrogen signaling; however, combination therapy resulted in increased cytokine signaling and adaptive immune response indicative of enhanced antigen presentation and activated T-cell phenotypes., Conclusions: Abemaciclib plus anastrozole demonstrated biological and clinical activity with generally manageable toxicities in patients with HR+ /HER2- early breast cancer. Abemaciclib led to potent cell-cycle arrest, and in combination with anastrozole, enhanced immune activation., (©2019 American Association for Cancer Research.)- Published
- 2020
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