Efficacy and toxicity of trastuzumab emtansine among patients with HER-2-positive metastatic breast cancer in Saudi Arabia

• Published in: Journal of clinical oncology Vol. 42; no. 16_suppl
• Main Authors: Badran, Ahmed Ali, Fallatah, Waleed, Hinkston, Abdullaah Khaleel, Arabi, Tarek, Algwaiz, Ghada, Elshenawy, Mahmoud Abdelsatar, Elshentenawy, Ayman, Haque, Emaan Ul, Twegieri, Taher, Akhtar, Saad, Alsayed, Adher, Ajarim, Dahish Saed, Alzahrani, Meshari, Alaklabi, Sabah, Elhassan, Tusneem, Suleman, Kausar
• Format: Journal Article
• Language: English
• Published: 01.06.2024
• ISSN: 0732-183X; 1527-7755
• DOI: 10.1200/JCO.2024.42.16_suppl.e13001

e13001 Background: Trastuzumab emtansine (T-DM1) significantly prolongs progression-free survival (PFS) with a safe drug profile in advanced HER-2-positive (HER+) breast cancer (BC) patients. However, there are currently no reports regarding its efficacy and safety in the Middle East. Methods: We retrospectively reviewed the data of 55 metastatic HER+ BC patients who received T-DM1 at our center. Results: The median age at diagnosis was 44 years (25-69). 65.45% patients presented as a de novo metastatic presentation and 56.46% were hormone receptor-positive (Table). 80%, 65.45%, 43.63% suffered visceral, CNS, and skeletal metastasis, respectively. The median duration of follow up was 31.5 months (3-61). 54.45% of patients were alive with disease at the date of last follow up, and 35.45% passed away. The median number of cycles given was 12 cycles (1-60). The best response, according to RECIST criteria v1.1, was complete remission in 5.45%, partial response in 40%, and stable disease in 23.64%. The mean overall survival (OS) was 117.3 months (95% CI: 97.35-137.24), and the median OS was not reached. The median PFS was 10.91 months (95% CI: 5.61-16.21) and the 3-year PFS was 17.6%. Four patients are still receiving T-DM1 treatment at the time of analysis. 85.45% stopped their treatment due to disease progression, and two (3.63%) patients stopped due to severe drug toxicity. Drop in ejection fraction and allergic reactions were the most common side effects, which were both seen in 18.18% of patients. Conclusions: The efficacy and safety profile of T-DM1 in our patient is comparable to that of other international populations. Larger, multicenter studies are needed to confirm our findings. ECOG performance status at presentation 0 6 (10.7%) 1 45 (80.4%) 2 4 (7.1%) Metastectomy Brain 10 (18.18%) Bone 1 (1.81%) Lungs 1 (1.81%) Total number of drug lines 2-4 31 (56.36%) 5-7 23 (41.81%) 8 1 (1.81%)