Postmastectomy Radiation Therapy: An ASTRO-ASCO-SSO Clinical Practice Guideline
Guidelines for post-mastectomy radiation include patients who received neoadjuvant therapy, with or without residual disease after treatment. A good topic to review.
Abemaciclib Plus Fulvestrant in Advanced Breast Cancer After Progression on CDK4/6 Inhibition: Results From the Phase III postMONARCH Trial
Author(s): Kevin Kalinsky, MD, MS, FASCO1; Giampaolo Bianchini, MD2; Erika Hamilton, MD3; Stephanie L. Graff, MD4; Kyong Hwa Park, MD, PhD5; Rinath Jeselsohn, MD6; Umut Demirci, MD, PhD7; Miguel Martin, MD, PhD8; Rachel M. Layman, MD9; Sara A. Hurvitz, MD10; Sarah Sammons, MD6; Peter A. Kaufman, MD11; Montserrat Muñoz, MD12; Jiun-I Lai, MD, PhD13; Holly Knoderer, MD, MBA, MSc14; Cynthia Sandoval, PhD14; Aarti R. Chawla, PhD14; Bastien Nguyen, PhD14; Yanhong Zhou, PhD14; Elizabeth Ravenberg, PhD14; Lacey M. Litchfield, PhD14; Lillian Smyth, MD14; Seth A. Wander, MD, PhD15;
Source: https://doi.org/10.1200/JCO-24-02086
Dr. Anjan Patel's Thoughts
Yet another combination to consider after CDK4/6i + ET in HR+ MBC!
PURPOSE
Cyclin-dependent kinase 4/6 inhibitors (CDK4/6i) combined with endocrine therapy (ET) are the standard first-line treatment for hormone receptor–positive (HR+), human epidermal growth factor receptor 2–negative (HER2–) advanced breast cancer (ABC); however, disease progression occurs in almost all patients and additional treatment options are needed. Herein, we report outcomes of the postMONARCH trial investigating a switch in ET with/without CDK4/6 inhibition with abemaciclib after disease progression on CDK4/6i.
METHODS
This double-blind, randomized phase III study enrolled patients with disease progression on previous CDK4/6i plus aromatase inhibitor as initial therapy for advanced disease or recurrence on/after adjuvant CDK4/6i + ET. Patients were randomly assigned (1:1) to abemaciclib + fulvestrant or placebo + fulvestrant. The primary end point was investigator-assessed progression-free survival (PFS). Secondary end points included PFS by blinded independent central review, objective response rate (ORR), and safety.
RESULTS
This study randomly assigned 368 patients (abemaciclib + fulvestrant, n = 182; placebo + fulvestrant, n = 186). At the primary analysis (258 events), the hazard ratio (HR) was 0.73 (95% CI, 0.57 to 0.95; nominal P = .017), with median PFS 6.0 (95% CI, 5.6 to 8.6) versus 5.3 (95% CI, 3.7 to 5.6) months and 6-month PFS rates of 50% and 37% in the abemaciclib + fulvestrant and placebo + fulvestrant arms, respectively. These results were supported by BICR-assessed PFS (HR, 0.55 [95% CI, 0.39 to 0.77]; nominal P < .001). A consistent treatment effect was seen across major clinical and genomic subgroups, including with/without ESR1 or PIK3CA mutations. Among patients with measurable disease, investigator-assessed ORR was improved with abemaciclib + fulvestrant versus placebo + fulvestrant (17% v 7%; nominal P = .015). No new safety signals were observed, with findings consistent with the known safety profile of abemaciclib.
CONCLUSION
Abemaciclib + fulvestrant significantly improved PFS after disease progression on previous CDK4/6i + ET in patients with HR+, HER2– ABC, offering an additional targeted therapy option for these patients.
Author Affiliations
1Winship Cancer Institute at Emory University, Atlanta, GA; 2IRCCS Ospedale San Raffaele, Vita-Salute San Raffaele University, Milan, Italy; 3Sarah Cannon Research Institute, Nashville, TN; 4Brown University Health, Legorreta Cancer Center at Brown University, Providence, RI; 5Korea University Anam Hospital, Korea University, Seoul, South Korea; 6Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA; 7Memorial Ankara Hospital, Ankara, Turkey; 8Hospital General Universitario Gregorio Maranon, Universidad Complutense, Madrid, Spain; 9MD Anderson Cancer Center, University of Texas, Houston, TX; 10Fred Hutchinson Cancer Center, University of Washington School of Medicine, Seattle, WA; 11University of Vermont Medical Center, Burlington, VT; 12Hospital Clinic and Translational Genomics and Targeted Therapeutics, Institut d’Investigacions Biomediques Pi I Sunyer-IDIBAPS, Barcelona, Spain; 13Taipei Veterans General Hospital, Taipei, Taiwan; 14Eli Lilly and Company, Indianapolis, IN; 15Massachusetts General Hospital, Harvard University, Boston, MA;Related Articles
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