Medication-driven management and heterogeneous prophylaxis patterns in T-DXd-related emesis. Results of the worldwide HERMIONE-EDUcational project

Abstract

Background: T-DXD is a standard treatment for HER2-positive and HER2-low unresectable breast cancer. Clinical trials from the DESTINY program reported adverse events (AE) such as nausea, fatigue, and interstitial lung disease (ILD) which require careful monitoring. Real-world data emphasized the need for proactive AE management to optimize outcomes. The HERMIONE-EDUcational project was launched to collect global clinical insights on T-DXD use and AE management in practice. Data regarding the management of nausea and vomiting during T-DXD are presented. Method(s): A survey was conducted across 120 oncologists with a demonstrated expertise in BC management in 13 countries worldwide to describe clinicians' management of T-DXd-related adverse events in women with metastatic breast cancer. Responsiveness to the survey was 82.5%. Result(s): Nausea and vomiting management relies mainly on supportive care, with dose modifications rarely needed. For prophylaxis, clinicians very often use NK1 receptor antagonists (NK1-RA) (65.7%), serotonin antagonists (69.7%), and corticosteroids (55.6%). Dopamine antagonists, olanzapine, H1 antihistamines, and antimuscarinics are used more variably. Combination regimens including NK1-RA, corticosteroids, and serotonin antagonists are frequent (55.6%). Rescue therapy typically involves steroids (32.3%), metoclopramide (24.2%), or both (29.3%). Use of a 4-drug regimen (NK1-RA + olanzapine + 5HT3 antagonist) varies: 44% prescribe it after cycle-1 symptoms > grade 1, 35% reserve it for high-risk patients. Monitoring is active in most centres, with nurses overseeing 58% of cases. Conclusion(s): Overall, the findings indicate that clinicians tend to use an assertive approach to antiemetic prophylaxis that is largely consistent with current guidelines, although notable variability remains in the selection of specific agents and in escalation practices. Establishing more standardized, T-DXd-focused antiemetic recommendations-along with reinforcing supportive care resources-could help minimize this variability and further improve patient outcomes. Legal entity responsible for the study: Marina Elena Cazzaniga. Funding(s): HELSINN; DAIICHI SANKYO. Disclosure: M.E. Cazzaniga: Financial Interests, Personal, Invited Speaker: HELSINN, Pierre Fabre; Financial Interests, Personal, Advisory Board: Novartis, Menarini Stemline. M.S. Aapro: Financial Interests, Personal, Invited Speaker: AMGEN, IMMEDICA, KNIGHT THERAPEUTICS, VIFORPHARMA; Other, Institutional, Research Grant: AstraZeneca, DAIICHI SANKYO, FRESENIUS KABI; Financial Interests, Institutional, Research Grant: HELSINN; Other, Institutional, Funding: LILLY, MUNDIPHARMA, NOVARTIS, PFIZER; Other, Institutional, Member of Board of Directors: ALL CAN, SPCC; Financial Interests, Personal, Member of Board of Directors: UICC; Other, Personal, Member of Board of Directors: EUROPEAN SCHOOL OF ONCOLOGY. A. Charalambous: Non-Financial Interests, Personal, Member of Board of Directors: MASCC, IASLC; Non-Financial Interests, Personal, Leadership Role: ECO, EONS; Non-Financial Interests, Personal, Advisory Board: SPCC; Financial Interests, Institutional, Funding: AMGEN, TAKEDA; Financial Interests, Personal, Advisory Role: MEDSCAPE, TOUCHIME, MSD, DAIICHI SANKYO, ASTRAZENECA. L. Cortesi: Financial Interests, Personal, Advisory Role: ASTRAZENECA, MSD, PFIZER; Financial Interests, Personal, Invited Speaker: NOVARTIS, GILEAD, ROCHE, DAIICHI SANKYO. P.A. Fasching: Financial Interests, Personal, Advisory Board: Roche, Novartis, Pfizer, Daiichi-Sankyo, Eisai, Merck, Sharp & Dohme, AstraZeneca, Hexal, Lilly, Seagen, Agendia, Sanofi Aventis, Medac, Menarini, Veracyte; Financial Interests, Personal, Invited Speaker: Novartis, Daiichi-Sankyo, Eisai, Merck, Sharp & Dohme, AstraZeneca, Lilly, Seagen, Gilead, Mylan, Guardant Health, Sysmex, Synlab; Financial Interests, Personal, Other, Medical Writing Support: Roche; Financial Interests, Institutional, Invited Speaker: BionTech, Cepheid; Non-Financial Interests, Member: ASCO, Arbeitsgemeinschaft fur Gynakologische Onkologie e.V., Translational Research in Oncology, Deutsche Gesellschaft fur Senologie e.v. G. Freyer: Financial Interests, Personal, Research Grant: ASTRAZENECA, LILLY, PFIZER, GILEAD, DAIICHI SANKYO, NOVARTIS; Financial Interests, Personal, Advisory Role: BEIGENE. H. Iihara: Financial Interests, Personal, Invited Speaker: ASTELLAS PHARMA, CHUGAI PHARMACEUTICAL, DAIICHI SANKYO, ELI LILLY, GILEAD, NIPPON KAJAKU, OHARA PHARMACEUTICAL, AWAI PHARMACEUTICAL, TAIHO. Y.H. Park: Financial Interests, Personal, Advisory Board: AstraZeneca, Pfizer, Roche, Novartis, MSD, Daiichi Sankyo, Helsinn, Voronoi, Aimed BIo; Financial Interests, Personal, Invited Speaker: AstraZeneca, Pfizer, Roche, Novartis, MSD, Daiichi Sankyo, Lilly; Financial Interests, Institutional, Other, Research Grant: AstraZeneca, Pfizer, Roche, MSD; Non-Financial Interests, Principal Investigator: AstraZeneca, Pfizer, Novartis, MSD, Lilly, Roche, Daiichi Sankyo. H.S. Rugo: Financial Interests, Personal, Advisory Board, Consultancy/advisory support: Napo; Financial Interests, Personal, Other, Advisory/Consultant: Bristol Myers Squibb; Financial Interests, Personal, Other, Consulting/Advisory Role: Helsinn, Biontech Rna Pharmacuticals GMBH; Financial Interests, Institutional, Invited Speaker: Novartis, Lilly, Pfizer, F. Hoffmann-La Roche AG/Genentech, Inc., Daiichi Sankyo, AstraZeneca, Gilead Sciences, Inc., Merck; Financial Interests, Institutional, Research Grant: Stemline Therapeutics, Ambryx, Bicycle Therapeutics. H. Sakai: Financial Interests, Personal, Invited Speaker, speaker honorarium: Daiichi Sankyo, Eli Lilly, Gilead Sciences, AstraZeneca, Pfizer; Financial Interests, Institutional, Invited Speaker: Eli Lilly; Non-Financial Interests, Personal, Other, medical writing support: Daiichi Sankyo. All other authors have declared no conflicts of interest. Copyright © 2026