SABCS 2025 Unveils Breakthroughs in Breast Cancer Treatments

The San Antonio Breast Cancer Symposium (SABCS) 2025, held from December 9 to 12 in San Antonio, Texas, showcased groundbreaking advancements in breast cancer treatment. Clinicians, researchers, and oncology pharmacists convened to discuss new data that could reshape treatment practices across various breast cancer subtypes. Key highlights included advancements in targeted therapies, refining treatment sequences, and the growing role of pharmacists in precision oncology.

One of the focal points of the symposium was the long-term results from the MONALEESA trials, which evaluated ribociclib (Kisqali; Novartis), a CDK4/6 inhibitor, in patients with hormone receptor-positive (HR+), HER2-negative advanced breast cancer. The updated findings indicated substantial long-term disease control, demonstrating sustained progression-free survival benefits and manageable safety profiles. These results reaffirmed the significance of ribociclib as a foundational component in standard endocrine therapy regimens for HR+ metastatic breast cancer.

Redefining Standards of Care with DESTINY-Breast Trials

Emerging analyses from the DESTINY-Breast trial portfolio highlighted the potential of trastuzumab deruxtecan (T-DXd, Enhertu; Daiichi Sankyo) in expanding treatment options for both HER2-positive and HER2-low patient populations. Presentations emphasized improvements in systemic control and patient outcomes, suggesting that the expanded use of this antibody-drug conjugate (ADC) may redefine current standards of care in breast cancer management.

Another significant study presented at the symposium was HER2CLIMB-05, which investigated the impact of adding tucatinib (Tukysa; Array BioPharma) to maintenance treatments involving trastuzumab (Herceptin; Genentech) and pertuzumab (Perjeta; Genentech). The results revealed an impressive 8.6-month improvement in median progression-free survival (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 longer, positively affecting their quality of life.

While central nervous system (CNS) PFS data remains immature, preliminary analyses indicated a potential doubling of PFS in patients with baseline brain metastases. These findings reinforce tucatinib’s growing role in managing CNS disease, as previously observed in other HER2CLIMB studies.

Addressing Safety and Supportive Care in Oncology

A central theme of SABCS 2025 was the evolving role of ADCs in treating HER2-positive breast cancer, particularly in patients with CNS involvement. Historically, the blood-brain barrier has limited therapeutic options for brain metastases, which affect up to 50% of patients with advanced HER2+ disease. ADCs such as T-DXd and sacituzumab govitecan (SG; Trodelvy, Gilead Sciences) demonstrated meaningful intracranial activity, achieving response rates around 50% and encouraging PFS in patients with brain metastases.

In addition to novel therapies, the symposium addressed practical considerations in supportive care, particularly the use of GLP-1 agonists in oncology settings. Discussions focused on vigilant monitoring for gastrointestinal side effects, appropriate dose adjustments based on patient tolerance, and the importance of interdisciplinary coordination to mitigate adverse events. These strategies aim to leverage the metabolic benefits of GLP-1 agonists, supporting overall patient well-being during cancer therapy.

The expanding role of pharmacists in precision oncology emerged as a recurring theme throughout the symposium. With the increasing complexity of targeted agents and biomarker-guided therapy selection, pharmacists are uniquely positioned to enhance therapeutic outcomes. Their roles include interpreting genomic profiles, managing drug-drug interactions, and educating patients about novel regimens, making them integral to multidisciplinary care teams.

As the data presented at SABCS 2025 highlights a shift toward individualized treatment pathways, clinicians and oncology pharmacists face both challenges and opportunities. Integrating these emerging findings into practice—selecting the right patients for novel regimens, balancing efficacy with safety, and evolving supportive care paradigms—will be crucial for optimizing treatment in breast cancer.