First-Line and Maintenance Therapy for Patients with ER-Positive, HER2-Positive Metastatic Breast Cancer — Part 1 of 2

Faculty

Faculty

Virginia F Borges

MD, MMSc

University of Colorado Anschutz Medical Campus, Aurora, Colorado

Professor of Medicine with Tenure, Robert F and Patricia Young Connor Endowed Chair in Young Women’s Breast Cancer Research, Deputy Division Head, Medical Oncology, Co-Director, Diane O’Connor Thompson Breast Center, Co-Director, Breast Cancer Research Program, Director, Young Women’s Breast Cancer Translational Program

Faculty

Ian E Krop

MD, PhD

Yale Cancer Center, New Haven, Connecticut

Associate Cancer Center Director for Clinical Research, Medical Director, Clinical Trials Office

Translational Breast Cancer Research Consortium, New Haven, Connecticut

Chief Scientific Officer

TARGET AUDIENCE
This program is intended for medical oncologists, breast surgeons, radiation oncologists and other healthcare professionals involved in the diagnosis and treatment of breast cancer.

LEARNING OBJECTIVES

• Review the pathophysiology and prognosis of hormone receptor (HR)-positive, HER2-positive breast cancer, and understand the implications for therapeutic decision-making.
• Appraise available clinical research data, current guideline recommendations and expert best practices to guide the selection of first-line and maintenance therapy for patients with newly diagnosed HR-positive, HER2-positive metastatic breast cancer (mBC).
• Assess recently published Phase III data with HER2-directed antibody-drug conjugate therapy as a component of first-line therapy, and consider the current role of this novel strategy in treatment for patients with HR-positive, HER2-positive mBC.
• Appreciate the biological rationale for and available research findings with CDK4/6 inhibition in combination with endocrine and anti-HER2 maintenance therapy for patients with HR-positive, HER2-positive mBC, and use this information to personalize treatment recommendations.

ACCREDITATION STATEMENT
Research To Practice is accredited by the Accreditation Council for Continuing Medical Education (ACCME) to provide continuing medical education for physicians.

CREDIT DESIGNATION STATEMENT
Video Proceedings: Research To Practice designates this enduring material for a maximum of 1.25 AMA PRA Category 1 Credits™. Physicians should claim only the credit commensurate with the extent of their participation in the activity.

AMERICAN BOARD OF INTERNAL MEDICINE (ABIM) — MAINTENANCE OF CERTIFICATION (MOC)
Successful completion of this CME activity, which includes participation in the evaluation components and a post-test, enables the participant to earn up to 1.25 (video) Medical Knowledge MOC points in the American Board of Internal Medicine’s (ABIM) Maintenance of Certification (MOC) program. Participants will earn MOC points equivalent to the amount of CME credits claimed for each activity. It is the CME activity provider’s responsibility to submit participant completion information to ACCME for the purpose of granting ABIM MOC credit.

Please note, these programs have been specifically designed for the following ABIM specialty: medical oncology.

AMERICAN BOARD OF SURGERY (ABS) — CONTINUOUS CERTIFICATION (CC)
Successful completion of these CME activities, which includes participation in the evaluation component and post-tests, enables the learner to earn credit toward the CME and Self-Assessment requirement(s) of the American Board of Surgery’s Continuous Certification program. It is the CME activity provider’s responsibility to submit participant completion information to ACCME for the purpose of granting ABS credit.

Please note, these programs have been specifically designed for the following ABS practice area: complex general surgical oncology.

PRIVACY POLICY
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HOW TO USE THIS CME ACTIVITY
Video Program: This CME activity consists of a video component. To receive credit, the participant should review the CME information, watch the video, complete the post-test with a score of 80% or better and fill out the evaluation located at ResearchToPractice.com/FirstLineTherapyHER2mBC26/1/Video/CME.

CONTENT VALIDATION AND DISCLOSURES
Research To Practice (RTP) is committed to providing its participants with high-quality, unbiased and state-of-the-art education and adheres to the ACCME’s Standards for Integrity and Independence in Accredited Continuing Education. Any individuals in a position to control the content of an accredited continuing education activity, including faculty, planners, reviewers and others, are required to disclose all relevant financial relationships with ineligible entities (commercial interests). All relevant financial relationships have been mitigated prior to the commencement of this activity. In addition, all activity content is reviewed by RTP scientific staff and an external, independent physician reviewer for fair balance, scientific objectivity of studies referenced and patient care recommendations.

FACULTY — The following faculty reported relevant financial relationships with ineligible entities:

Virginia F Borges, MD, MMSc
Professor of Medicine with Tenure
Robert F and Patricia Young Connor Endowed Chair in Young Women’s Breast Cancer Research
Deputy Division Head, Medical Oncology
Co-Director, Diane O’Connor Thompson Breast Center
Co-Director, Breast Cancer Research Program
Director, Young Women’s Breast Cancer Translational Program
University of Colorado Anschutz Medical Campus
Aurora, Colorado

Advisory Committees: AstraZeneca Pharmaceuticals LP, Gilead Sciences Inc, Pfizer Inc; Consulting Agreements: Gilead Sciences Inc, Olema Oncology, Pfizer Inc; Contracted Research: AstraZeneca Pharmaceuticals LP, Gilead Sciences Inc, Merck, Olema Oncology, Pfizer Inc.

Ian E Krop, MD, PhD
Associate Cancer Center Director for Clinical Research
Medical Director, Clinical Trials Office
Yale Cancer Center
Chief Scientific Officer
Translational Breast Cancer Research Consortium
New Haven, Connecticut

Advisory Committees: AstraZeneca Pharmaceuticals LP, Bristol Myers Squibb, Daiichi Sankyo Inc, EMD Serono Inc, Genentech, a member of the Roche Group, Lilly, Seagen Inc; Consulting Agreements: ALX Oncology, AstraZeneca Pharmaceuticals LP, Genentech, a member of the Roche Group, Halda Therapeutics, Novartis; Contracted Research: Pfizer Inc; Data and Safety Monitoring Boards/Committees: Novartis, Seagen Inc.

MODERATOR — Dr Love is president and CEO of Research To Practice. Research To Practice receives funds in the form of educational grants to develop CME activities from the following companies: Aadi Bioscience, AbbVie Inc, ADC Therapeutics, Agendia Inc, Alexion Pharmaceuticals, Amgen Inc, Array BioPharma Inc, a subsidiary of Pfizer Inc, Arvinas, Astellas, AstraZeneca Pharmaceuticals LP, Aveo Pharmaceuticals, Bayer HealthCare Pharmaceuticals, BeOne, Biotheranostics Inc, A Hologic Company, Black Diamond Therapeutics Inc, Blueprint Medicines, Boehringer Ingelheim Pharmaceuticals Inc, Bristol Myers Squibb, Celcuity, Clovis Oncology, Coherus BioSciences, Corcept Therapeutics Inc, CTI BioPharma, a Sobi Company, Daiichi Sankyo Inc, Eisai Inc, Elevation Oncology Inc, Exact Sciences Corporation, Exelixis Inc, Genentech, a member of the Roche Group, Genmab US Inc, Geron Corporation, Gilead Sciences Inc, GSK, Helsinn Therapeutics (US) Inc, ImmunoGen Inc, Incyte Corporation, Ipsen Biopharmaceuticals Inc, Jazz Pharmaceuticals Inc, Johnson & Johnson, Karyopharm Therapeutics, Kite, A Gilead Company, Kura Oncology, Legend Biotech, Lilly, MEI Pharma Inc, Merck, Mersana Therapeutics Inc, Mirati Therapeutics Inc, Mural Oncology Inc, Natera Inc, Novartis, Novartis Pharmaceuticals Corporation on behalf of Advanced Accelerator Applications, Novocure Inc, Nuvalent, Nuvation Bio Inc, Pfizer Inc, Pharmacyclics LLC, an AbbVie Company, Puma Biotechnology Inc, Regeneron Pharmaceuticals Inc, Revolution Medicines Inc, Rigel Pharmaceuticals Inc, R-Pharm US, Sanofi, Seagen Inc, Servier Pharmaceuticals LLC, SpringWorks Therapeutics Inc, Stemline Therapeutics Inc, Sumitomo Pharma America, Summit Therapeutics, Syndax Pharmaceuticals, Taiho Oncology Inc, Takeda Pharmaceuticals USA Inc, TerSera Therapeutics LLC, and Tesaro, A GSK Company.

RESEARCH TO PRACTICE CME PLANNING COMMITTEE MEMBERS, STAFF AND REVIEWERS — Planners, scientific staff and independent reviewers for Research To Practice have no relevant financial relationships to disclose.

These educational activities contain discussion of published and/or investigational uses of agents that are not indicated by the Food and Drug Administration. Research To Practice does not recommend the use of any agent outside of the labeled indications. Please refer to the official prescribing information for each product for discussion of approved indications, contraindications and warnings. The opinions expressed are those of the presenters and are not to be construed as those of the publisher or grantor.

These activities are supported by an educational grant from Pfizer Inc.

Release date: April 2026
Expiration date: April 2027

After completing the post-test, learners may download and review the answers here in order to identify further areas of study.

Bischoff H, Petit T. CDK4/6 inhibitors in HER2-positive metastatic breast cancer. Clin Breast Cancer 2026;26(2):93-104. Abstract

Dieras V et al. HER2CLIMB-05: A phase III study of tucatinib versus placebo in combination with trastuzumab and pertuzumab as first-line maintenance therapy for HER2+ metastatic breast cancer. J Clin Oncol 2025;[Online ahead of print]. Abstract

Hamilton EP et al. HER2CLIMB-05: Phase 3 study of tucatinib or placebo in combination with trastuzumab and pertuzumab as maintenance therapy for HER2+ metastatic breast cancer. ASCO 2023;Abstract TPS1115.

Kuemmel S et al. heredERA Breast Cancer: A phase III, randomized, open-label study evaluating the efficacy and safety of giredestrant plus the fixed-dose combination of pertuzumab and trastuzumab for subcutaneous injection in patients with previously untreated HER2-positive, estrogen receptor-positive locally advanced or metastatic breast cancer. BMC Cancer 2024;24(1):641. Abstract

Loibl S et al. Trastuzumab deruxtecan (T-DXd) + pertuzumab (P) vs taxane + trastuzumab + pertuzumab (THP) for patients (pts) with HER2+ advanced/metastatic breast cancer (a/mBC): Additional analyses of DESTINY-Breast09 in key subgroups of interest. ESMO 2025;Abstract LBA18.

Metzger O et al. Palbociclib for hormone-receptor-positive, HER2-positive advanced breast cancer. N Engl J Med 2026;394(5):451-62. Abstract

Metzger O et al. Central nervous system outcomes from the phase III PATINA trial (AFT-38). San Antonio Breast Cancer Symposium 2025;Abstract RF4-01.

Swain SM et al. INAVO122: A phase III study of maintenance inavolisib or placebo + pertuzumab + trastuzumab following induction with pertuzumab + trastuzumab + a taxane in patients (pts) with PIK3CA-mutated, HER2-positive advanced breast cancer (HER2+ aBC). ASCO 2024;Abstract TPS1124.

Swain SM et al. Pertuzumab, trastuzumab, and docetaxel in HER2-positive metastatic breast cancer. N Engl J Med 2015;372(8):724-34. Abstract

Tolaney SM et al. Trastuzumab deruxtecan plus pertuzumab for HER2-positive metastatic breast cancer. N Engl J Med 2025;[Online ahead of print]. Abstract

Tolaney SM et al. Trastuzumab deruxtecan (T-DXd) + pertuzumab (P) vs taxane + trastuzumab + pertuzumab (THP) for first-line (1L) treatment of patients (pts) with human epidermal growth factor receptor 2–positive (HER2+) advanced/metastatic breast cancer (a/mBC): Interim results from DESTINY-Breast09. ASCO 2025;Abstract LBA1008.

Vaz-Luis IV et al. Health-related quality of life (HRQoL) from the PATINA trial (AFT-38): Impact of adding palbociclib to HER2 and endocrine therapy (ET) after induction in HR+/HER2+ metastatic breast cancer (MBC). ESMO 2025;Abstract 485MO.