Abstract PO4-12-10: Sacituzumab Govitecan Toxicity Outcomes In Arab Patients with Metastatic Breast Cancer
Authors: Altarturi Maymouna , Suleman Kausar , AlSayed Adhar , Al-Shamsi Humaid , Alawadhi Aydah , Basuliamn Bassam , Alaklabi Sabah 
Published: May 2024

Abstract
Background:
The Arab population is often underrepresented in clinical trials, which limits our knowledge of drug safety and efficacy in this population due to genetic variability that can affect drug metabolism and adverse events (AEs). Sacituzumab govitecan (SG) is approved for metastatic triple negative breast cancer (mTNBC), and recently hormone receptor positive metastatic breast cancer (HR+ MBC). Here we report toxicity outcomes and RDI in Arab population.
Methods:
A multi-center retrospective study of patients with mTNBC and HR+ MBC treated with SG from January 2021 until May 2023 was conducted. Demographics and clinical variables including site of metastases, prior lines of therapy, relative dose intensity (RDI), adverse events (AEs) were collected. For continuous variables, Mann-U Whitney and Kruskal Wallis tests were used to compare mean, median, standard deviation, and range. For categorical variables, Fisher's exact tests and Pearson Chi-square tests were used. SAS v9.4 was used to perform statistical analysis at a significance level of 0.05.
Results:
A total of 35 patients was enrolled. The median age at diagnosis of metastatic breast cancer was 39 years interquartile range (IQR) (35, 44). The median age at starting SG was 44.5 years IQR (38,50). The majority of patients (65%) had an Eastern Cooperative Oncology Group performance status (ECOG PS) of 1, (21%) of the patients had an ECOG PS of 0, and (15%) had an ECOG PS of 2. 48.6% received 3 or more lines of prior therapy in the metastatic setting while 51.4% received less than 3 lines of prior therapy in the metastatic setting. 77.1% of patients had 3 or &gt; organs involved with metastatic disease, while 22.9% of patients had &lt; 3 organ involved. The most common metastatic sites were the lung (54.3%), liver (62.9%), bone (68.6%), and brain (45.7%). The median RDI of SG was 100% for a sample of 34 individuals, with one missing value IQR (94%,100%). The rate of overall AEs was (77.1%), with the most common AEs being; neutropenia (44.4%), diarrhea (37.0%), anemia (22.2%), thrombocytopenia (22.2%), nausea (14.8%), and vomiting (7.4%). Garde 3 AEs rate was 34.3%. The most common grade 3 adverse events were diarrhea (11.4%), fatigue (5.7%), and alopecia (2.9%). The rate of treatment interruption and dose reduction due to AEs was 31.4%. Only one patient (2.9%) had to discontinue SG treatment due to adverse events.
Conclusion:
The study suggests that SG is safe and well-tolerated in young Arab patient population. The sample consisted of relatively young patients, which may reflect a reluctance to prescribe SG to older Arab patients. Caution should be exercised when generalizing the findings due to limitations of the study. Further studies with larger sample sizes are needed to validate these findings and to explore the efficacy of SG in Arab patients with mTNBC and HR+ MBC.
Citation Format: Maymouna Altarturi, Kausar Suleman, Adhar AlSayed, Humaid Al-Shamsi, Aydah Alawadhi, Bassam Basuliamn, Sabah Alaklabi. Sacituzumab Govitecan Toxicity Outcomes In Arab Patients with Metastatic Breast Cancer [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO4-12-10.