Breast Cancer

Chicago, IL—The addition of the cyclin-dependent kinase (CDK)4/CDK6 inhibitor ribociclib (Kisqali) to standard endocrine therapy significantly extended overall survival (OS) compared with endocrine therapy alone in premenopausal women with hormone receptor (HR)-positive, HER2-negative advanced breast cancer, according to results of the phase 3 MONALEESA-7 clinical trial presented at ASCO 2019.

Approximately 40% of patients with hormone receptor (HR)-positive, HER2-negative breast cancer have mutations in the PIK3CA gene. Although endocrine­based therapy is the standard treatment, acquired resistance remains a challenge.

The adjuvant use of the antibody-drug conjugate trastuzu­mab emtansine (T-DM1; Kadcyla) led to a clinically meaningful and significant improvement in disease-free survival versus trastuzumab (Herceptin) in patients with HER2-positive early breast cancer and residual invasive disease, despite the use of neoadjuvant chemotherapy plus HER2-targeted therapy.

On May 3, 2019, the US Food and Drug Administration (FDA) approved ado-trastuzumab emtansine (Kadcyla; Genentech) for the adjuvant treatment of patients with HER2-positive early breast cancer who have residual invasive disease after neoadjuvant taxane and trastuzumab-based treatment. Patients should be selected for treatment with this agent based on an FDA-approved companion diagnostic test (Ventana Medical System’s PATHWAY anti-HER-2/neu [4B5] Rabbit Monoclonal Primary Antibody assay or INFORM HER2 Dual ISH DNA Probe Cocktail assay).

On March 11, 2019, the FDA approved trastuzumab-qyyp (Trazimera; Pfizer) as the fourth biosimilar to trastuzumab (Herceptin; Genentech) for the treatment of patients with HER2-positive breast cancer or HER2-positive metastatic gastric or gastroesophageal junction adenocarcinoma. This approval was based on several studies confirming that trastuzumab-qyyp is biosimilar to the originator drug, Herceptin.

San Antonio, TX—Reaching pathologic complete response (pCR) after neo­adjuvant chemotherapy correlates with significantly improved event-free survival (EFS) and overall survival (OS) in patients with localized breast cancer, according to results of a large comprehensive meta-analysis presented at the 2018 San Antonio Breast Cancer Symposium.

San Antonio, TX—The large, randomized TAM-01 clinical trial demonstrated that 5 mg daily of tamoxifen for 3 years halved the risk for recurrence of breast intraepithelial neoplasia—atypical ductal hyperplasia, ductal carcinoma in situ (DCIS), and lobular carcinoma in situ—in women after surgery and reduced the risk for new contralateral breast cancer by 75% compared with placebo.

Orlando, FL—Options for the treatment of patients with advanced hormone receptor (HR)-positive, HER2­negative breast cancer are expanding. The updated National Comprehensive Cancer Network (NCCN) guideline (version 1.2019) for the management of invasive breast cancer is focused on HR-positive, HER2-negative disease. William J. Gradishar, MD, Director, Maggie Daley Center for Women’s Cancer Care, Robert H. Lurie Comprehensive Cancer Center, Northwestern University, Chicago, IL, discussed the updated guideline at the NCCN 2019 Conference.

On February 28, 2019, the FDA approved a combination of the HER2/neu receptor agonist trastuzumab plus the endoglycosidase hyaluronidase-oysk (Herceptin Hylecta; Genentech) subcutaneous (SC) injection for adults with HER2-overexpressing breast cancer in the adjuvant setting, as part of a regimen with chemotherapy or as monotherapy after multimodality an­thracycline-based therapy; and as first-line treatment for metastatic disease, in combination with paclitaxel, or as monotherapy after ≥1 chemotherapies in the metastatic setting. This SC injection is a new formulation of intravenous (IV) trastuzumab.

San Antonio, TX—Adding the PD-L1 inhibitor atezolizumab (Tecentriq) to nab-paclitaxel (Abraxane) chemother­apy is the first immunotherapy-based combination to improve progression-free survival (PFS) and overall survival (OS) in women with advanced or metastatic triple-negative breast cancer and PD-L1 expression compared with placebo plus nab-paclitaxel, according to results of the IMpassion130 clinical trial.