Abstract PS1-05-04: A multi-practice quality initiative evaluating antiemetic use in metastatic breast cancer patients treated with trastuzumab deruxtecan-nxki (T-DXd)

Abstract Background: As of January 2023, the National Comprehensive Cancer Network (NCCN) guidelines recommend using combinations of 5HT3, NK1, olanzapine (O), and dexamethasone (DEX) drugs as prophylaxis with highly emetic therapies, including fam-trastuzumab deruxtecan-nxki (T-DXd). An IntegraConnect PrecisionQ multi-practice quality initiative was conducted with Highlands Oncology Group (HOG), University of Pittsburgh Medical Center (UPMC), and Regional Cancer Care Associates (RCCA) to assess adherence to recommended antiemetic use in HER2-positive (HER2+) and HER2-low metastatic breast cancer (mBC) patients (pts) treated with T-DXd. This initiative compared current practices to NCCN guidelines, identified potential gaps in care, and implemented strategies to address these gaps. Our goal was to demonstrate improvements in antiemetic utilization for mBC pts treated with T-DXd as a result of this quality initiative. Methods: Using the IntegraConnect PrecisionQ de-identified database, HER2+ and HER2-low pts treated with T-DXd were evaluated for specific time periods at each practice related to antiemetic utilization. HOG (baseline: 1/1/2022-12/31/2023 and follow-up: 01/01/2024-06/04/2025), UPMC (baseline: 1/1/2022-04/30/2024 and follow-up: 05/01/2024-06/04/2025), RCCA (baseline: 1/1/2022-01/01/2024 and follow-up: 02/01/2024-06/04/2025). For the baseline period, we completed a retrospective analysis of the antiemetic utilization within the practices’ HER2+ and HER2-low patient cohorts. The results of the initial baseline analysis were shared with practice leaders and among oncologists at the practices. The practices updated antiemetic order-sets, and we evaluated the order-set changes during the follow-up period to account for any improvement in antiemetic utilization. Data are presented using descriptive statistics. Results: The total pts evaluated in the initiative were: HOG baseline (49 pts) and follow-up (27 pts); UPMC baseline (212 pts) and follow-up (110 pts); and RCCA baseline (132 pts) and follow-up (99 pts). In the follow-up analysis, utilization of the recommended combinations of antiemetics (5HT3+NK1+O±DEX or 5HT3+NK1±DEX) increased from 47% to 85% at RCCA, from 29% to 100% at UPMC, and from 49% to 100% at HOG, with the overall rate increasing from 37% to 94%. Conclusion: This multi-practice quality initiative led to improved antiemetic utilization that is in line with NCCN guidelines in HER2+ and HER2-low mBC pts treated with T-DXd. These findings highlight that with established guidelines, oncology practices can benefit from regularly evaluating their own data to assess their treatment compared to the latest clinical standards. Citation Format: S. Rosenfeld, O. Ajayi, R. Choksi, S. W. Champaloux, D. Parris, A. Rui, A. Lamb, M. Gart, C. Wall, B. Wang, P. Varughese, J. Donegan, L. Morere, R. Geller, J. Scott, V. Gorantla. A multi-practice quality initiative evaluating antiemetic use in metastatic breast cancer patients treated with trastuzumab deruxtecan-nxki (T-DXd) [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 PS1-05-04.