Cancer Therapy AdvisorSABCS 2023: Novel Therapies and a New Discovery in Metastatic Breast Cancer

Advancements in Metastatic Breast Cancer Treatment: Unveiling the Potential of Fusion RNAs and Investigational Therapies

The San Antonio Breast Cancer Symposium (SABCS) 2023 unveiled promising investigational therapies and a potential cause of treatment resistance in metastatic breast cancer. The studies highlighted the efficacy of adding tucatinib, avelumab, and datopotamab deruxtecan (Dato-DXd) to existing treatments, improving progression-free survival (PFS) in patients. Furthermore, a retrospective study identified fusion RNAs as potential drivers of therapy resistance, suggesting a new avenue for targeted treatment.

Key Points

• The HER2CLIMB-02 trial showed that adding tucatinib to trastuzumab emtansine (T-DM1) treatment extended PFS in patients with previously treated, HER2-positive metastatic or locally advanced breast cancer.
• The AVIATOR trial found that adding avelumab to vinorelbine and trastuzumab improved PFS in patients with HER2-positive advanced breast cancer who had previously been treated with trastuzumab, pertuzumab, and T-DM1.
• The TROPION-Breast01 trial showed that Dato-DXd improved PFS compared to standard chemotherapy in patients with previously treated, inoperable or metastatic, hormone receptor (HR)-positive, HER2-negative breast cancer.
• A retrospective study identified fusion RNAs that could be driving resistance to treatment in patients with metastatic breast cancer. Some of these fusions could potentially be targeted with existing small molecule inhibitors.

This [AVIATOR] is an interesting trial showing that immunotherapy has a place in HER2-positive disease as well. It’s interesting that the PD-L1 status didn’t make a difference in efficacy since prior studies suggested it should. I’m looking forward to larger trials that will definitively answer this question.
– Virginia Kaklamani, MD, co-director of SABCS and a professor of medicine at UT Health San Antonio in Texas, who was not involved in this study

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