Authors: Junjie Zhen, Shoaib Bashir, Yanying Yang, Hui Wang, Mingyao Lai, Linbo Cai
Published: 2024-07-23
DOI: 10.1200/jco.2024.42.16_suppl.e13017
Source: Full article
e13017 Background: Up to 50% of patients with breast cancer (BC) and human epidermal growth factor receptor 2 (HER2) positive present with disease progression in brain metastases (BM). Pyrotinib, an oral irreversible pan-HER receptor tyrosine kinase inhibitor, has shown efficacy in active central nervous system(CNS) metastases. However, clinical efficacy of pyrotinib combining with stereotactic radiosurgery (SRS) in BCBM is unclear. Methods: This retrospective, observational study collected data from 52 HER2+ BC patients with brain metastasis who received pyrotinib-based therapy in Guangdong Sanjiu brain hospital from 2019 to 2023. Among these patients, 36 received pyrotinib-based therapy combining with SRS concurrently, or within 1 months. Age, stage at diagnosis, dates of BM, primary tumor subtypes, prior systemic therapy, CNS-directed local therapy, the objective response and survival status were collected. The assessment of adverse effects was based on CTCAE 4.0. Results: 34 patients were evaluable for efficacy (median age: 51.5). With a median follow-up duration of 19.6 months, 1 patient (0.3%) achieved CR, while 27 patients (79.4%) had PR, resulting in an ORR of 82.3%. The median CNS PFS was 13.2 months (95% CI, 4.9-21.7). Median overall survival (OS) was 22.6 months (95% CI, 17.5-27.6). The most common grade 3 or worse treatment-emergent adverse event was diarrhea (6 [17.6%]). Conclusions: Our results suggest that pyrotinib combining with SRS is associated with promising efficacy and a satisfactory safety profile for Her2+ breast cancer brain metastases.