Breast Cancer

Chicago, IL—The addition of the CDK4/6 inhibitor ribociclib (Kisqali) to endocrine therapy significantly improved invasive disease-free survival in patients with hormone receptor (HR)-positive, HER2-negative, early breast cancer, according to interim results from the phase 3 NATALEE trial, which were presented at the 2023 American Society of Clinical Oncology Annual Meeting.

On March 3, 2023, the FDA approved abemaciclib (Verzenio; Eli Lilly) plus endocrine therapy (tamoxifen or an aromatase inhibitor) for the adjuvant treatment of adult patients with hormone receptor (HR)-positive, HER2-negative, node-positive, early breast cancer at high risk for recurrence.

On February 3, 2023, the FDA approved sacituzumab govitecan-hziy (Trodelvy; Gilead Sciences/Immunomedics) for the treatment of patients with unresectable, locally advanced or metastatic hormone receptor (HR)-positive, HER2-negative (immunohistochemistry [IHC] 0, IHC 1+, or IHC 2+ with a negative in situ hybridization test) breast cancer who have received endocrine-based therapy and at least 2 additional systemic therapies in the metastatic setting.

Young women with early-stage, hormone receptor-positive breast cancer attempting to become pregnant can safely pause endocrine therapy and resume it later, according to initial results from the international POSITIVE trial.

The FDA has issued a final rule intended to ensure patients are better informed about their breast tissue density when undergoing mammography. The rule updates regulations first issued in the 1990s under the Mammography Quality Standards Act to oversee mammography facilities and improve breast cancer testing.

Patients with hormone receptor (HR)-positive, HER2-negative advanced breast cancer, including those with visceral crises, treated with the CDK4/6 inhibitor ribociclib (Kisqali) plus endocrine therapy had a significantly longer progression-free survival (PFS) and fewer adverse events (AEs) compared with those treated with combination chemotherapy, according to results from the phase 2 RIGHT Choice trial.

On January 27, 2023, the FDA approved elacestrant (Orserdu; Stemline Therapeutics), an estrogen receptor (ER) antagonist, for the treatment of postmenopausal women or adult men with ER-positive, HER2-negative advanced or metastatic breast cancer and an ESR1 mutation whose disease progressed after ≥1 line of endocrine therapy.

Using circulating tumor cell (CTC) count to guide the choice of first-line treatment—chemotherapy or endocrine therapy—improved overall survival (OS) compared with investigator’s choice of treatment for patients with metastatic, estrogen receptor (ER)-positive, HER2-negative breast cancer, according to results from the STIC CTC trial, which were discussed at the 2022 San Antonio Breast Cancer Symposium (SABCS) by François-Clément Bidard, MD, PhD, Co-Coordinator, Breast Cancer Research, Institut Curie, Paris, France, and Professor, Medicine, Department of Medical Oncology, Institut Curie and Université de Versailles Saint-Quentin-en-Yvelines, France.

Targeting HER2 with the antibody–drug conjugate fam-trastuzumab deruxtecan-nxki (Enhertu; T-DXd) provided clinically meaningful benefits for patients with HER2-low metastatic breast cancer, according to findings presented at the 2022 American Society of Clinical Oncology Annual Meeting.

The investigational oral selective estrogen receptor degrader (SERD) elacestrant (RAD1901) significantly reduced the risk for death or disease progression and improved progression-free survival (PFS) compared with standard-of-care (SOC) endocrine therapy in patients with estrogen receptor (ER)-­positive, HER2-negative metastatic breast cancer who had progressed on previous endocrine and targeted therapies, according to results of the phase 3 EMERALD clinical trial.