SABCS 2025 Highlights Breakthroughs in Breast Cancer Treatment

The San Antonio Breast Cancer Symposium (SABCS) 2025, held from December 9 to 12 in San Antonio, Texas, showcased significant advancements in breast cancer treatment. Clinicians, researchers, and oncology pharmacists gathered to discuss emerging data that are reshaping therapy across various breast cancer subtypes. Key highlights included breakthroughs in targeted therapies and insights into the evolving role of pharmacists in precision oncology.

Innovative findings from the MONALEESA trials, which evaluated the CDK4/6 inhibitor ribociclib (Kisqali; Novartis) in hormone receptor-positive (HR+), HER2-negative advanced breast cancer, were a focal point of the symposium. Updated results indicated robust long-term disease control, with sustained progression-free survival (PFS) benefits and a manageable safety profile. These outcomes reinforce the integral role of ribociclib in standard endocrine therapy regimens, providing clinicians with greater confidence in achieving favorable long-term outcomes for patients.

Transformative Insights from the DESTINY-Breast Trials

Another significant contribution came from analyses of the DESTINY-Breast trial portfolio. Emerging data suggested that the expanded use of trastuzumab deruxtecan (T-DXd, Enhertu; Daiichi Sankyo) among both HER2-positive and HER2-low populations could redefine standards of care. Presenters highlighted improvements in systemic control and patient outcomes, which broaden the impact of antibody-drug conjugates (ADCs) across varying levels of HER2 expression.

A pivotal presentation from the HER2CLIMB-05 trial examined the addition of tucatinib (Tukysa; Array BioPharma) to maintenance therapy with trastuzumab (Herceptin; Genentech) and pertuzumab (Perjeta; Genentech) after initial treatment in metastatic HER2-positive breast cancer. Findings revealed a notable 8.6-month increase in median PFS, extending the duration without disease progression from approximately 18 months to nearly 25 months. This extension not only enhances disease control but also allows patients to avoid cytotoxic chemotherapy for longer, thereby improving their quality of life.

Advancing Antibody-Drug Conjugates and Supportive Care

The symposium also underscored the evolving role of ADCs in managing HER2-positive breast cancer, particularly in patients with central nervous system (CNS) involvement. Historically, the blood-brain barrier has limited therapeutic options for patients with brain metastases, which affect up to 50% of those with advanced HER2-positive disease. Data from the DESTINY-Breast12 trial indicated that ADCs like T-DXd and sacituzumab govitecan (SG; Trodelvy, Gilead Sciences) demonstrated significant intracranial activity with durable responses, reporting intracranial response rates around 50%.

In addition to novel therapies, discussions at SABCS 2025 highlighted important safety and dosing considerations in supportive care. There was a particular focus on the use of GLP-1 agonists in oncology settings, emphasizing the need for careful monitoring of gastrointestinal side effects, appropriate dose adjustments, and interdisciplinary collaboration to mitigate adverse effects while maximizing metabolic benefits.

The expanding role of pharmacists in precision oncology was a recurring theme throughout the symposium. With the increasing complexity of targeted therapies and biomarker-driven treatment strategies, pharmacists are becoming essential in enhancing therapeutic outcomes. Their contributions range from interpreting genomic profiles to managing drug interactions and educating patients about new regimens, solidifying their place in multidisciplinary care teams.

Data presented at SABCS 2025 collectively underscore a shift toward individualized treatment pathways. Clinical professionals face both challenges and opportunities in integrating these emerging findings into practice, ensuring that patient selection for novel therapies balances efficacy with safety while evolving supportive care paradigms alongside therapeutic advancements.