With respect to hormone receptor (HR)-positive, human epidermal growth factor 2 (HER2)-negative breast cancer, a post hoc analysis of the TAILORx trial was presented during SABCS 2024, in which the potential benefit of adding adjuvant anthracyclines to a taxane-containing regimen was evaluated according to genomic risk using Oncotype DX. In addition, in early breast cancer (EBC), nab-paclitaxel was compared to solvent-based (sb)-paclitaxel in the chemotherapy cohort of the WSG-ADAPT HR+/HER2- trial. Also, additional analyses related to the NATALEE trial were presented, including the effect of adjuvant ribociclib dose reduction on efficacy, and assessment of the benefit of ribociclib plus non-steroidal aromatase inhibitors (NSAIs) on distant disease-free survival (dDFS) across several subgroups. In the metastatic setting, SABCS 2024 featured the results of the phase III EMBER trial, which evaluated the efficacy and safety of imlunestrant as monotherapy or combined with abemaciclib in patients with endocrine-resistant oestrogen receptor (ER)-positive, HER2-negative metastatic breast cancer (MBC); they either progressed during adjuvant or first-line endocrine therapy (ET) and prior cyclin dependent kinase 4 or 6 inhibitor (CDK4/6i) was allowed. Moreover, the PADMA trial evaluated the use of palbociclib plus ET vs mono-chemotherapy in women with high-risk, previously untreated, HR-positive, HER2-negative MBC. Finally, an exploratory post hoc analysis of the DESTINY-Breast06 trial assessed the efficacy of trastuzumab deruxtecan (T-DXd) according to pace of progression on prior endocrine-based therapy.
