Abstract PS1-01-13: Examining Antiemetic Management with Antibody-Drug Conjugates (ADCs) in Patients with Breast Cancer: Healthcare Provider (HCP) Insights from a SABCS Survey

Abstract Background: Antibody-drug conjugates (ADCs) such as trastuzumab deruxtecan (T-DXd) and sacituzumab govitecan (SG) have revolutionized breast cancer (BC) treatment, providing superior efficacy that allows for extended treatment durations. Nausea and vomiting (NV) are among the most frequent adverse effects associated with T-DXd and SG, with nausea rates of >70% for T-DXd and >60% for SG in BC clinical trials. According to antiemetic guidelines, patients receiving T-DXd and SG are at moderate-to-high risk for NV and should routinely receive prophylaxis with an NK1 receptor antagonist (RA)-containing regimen. With limited real-world data on antiemetic efficacy in the ADC setting, a survey of international healthcare providers (HCPs) was conducted to assess their experience. Methods: At SABCS 2024, HCPs completed a brief web-based survey to assess their experiences and perceptions of ADC emetogenicity and approaches to antiemetic prophylaxis. Target participants included HCPs familiar with ADCs who manage patients with BC. Eligible participants completed the survey on computers located in the exhibit hall. Results: Of 209 HCPs surveyed, 112 were eligible. Most were oncologists (69%) or hematologist/oncologists (21%) who spent 73% of time in patient care; nearly half were US-based (46%). Among all HCPs, 80% reported using ADCs in practice and/or in clinical trials; 99% had experience with T-DXd and 87% with SG. Among HCPs using T-DXd and SG, 78% and 83%, respectively, perceived them as either highly (32% and 28%) or moderately (46% and 55%) emetogenic. NV reported by HCPs in this survey was much lower than in the T-DXd and SG clinical trials; HCPs reported that 30%, 25% and 15% of their BC patients treated with T-DXd experience N and/or V during the acute (0-24 hours), delayed (days 2-5), and long-delayed (beyond day 5) phases, respectively. Similarly, the reported NV rates were 29%, 26% and 13%, respectively, for SG. HCPs reported that 88% of patients treated with any ADCs in an average month receive antiemetic prophylaxis; however, only 39% of HCPs report exclusively using a guideline-recommended NK1 RA regimen with T-DXd or SG. The majority of HCPs (94%) reported implementing some type of dose adjustments of ADCs due to NV. A third to nearly half of HCPs had at least sometimes implemented an ADC dose reduction or delay due to NV while a quarter reported interrupting or discontinuing ADC treatment (Table). More than half reported using rescue medication at least sometimes for delayed NV. Conclusions: This survey highlights a gap between evidence and HCP perceptions regarding NV with T-DXd and SG, and reveals higher-than-expected dose reductions, likely reflecting suboptimal adherence to antiemetic guidelines. As ADCs gain prominence in BC treatment, these findings underscore the need for education and guideline-implementation to optimize NV prevention. Citation Format: L. S. Schwartzberg, L. Licata, G. Bianchini, Y. H. Park, E. J. Roeland, M. Massagrande, F. Dato, H. Iihara, F. Scotte, K. Jordan, M. Aapro, H. S. Rugo. Examining Antiemetic Management with Antibody-Drug Conjugates (ADCs) in Patients with Breast Cancer: Healthcare Provider (HCP) Insights from a SABCS Survey [abstract]. In: Proceedings of the San Antonio Breast Cancer Symposium 2025; 2025 Dec 9-12; San Antonio, TX. Philadelphia (PA): AACR; Clin Cancer Res 2026;32(4 Suppl):Abstract nr PS1-01-13.