Abstract 294P
Background
The aim of this study was to investigate the effect of pyrotinib, an irreversible pan-ErbB inhibitor, and capecitabine in the treatment of human epidermal growth factor receptor 2 (HER2)-positive breast cancer (BC) patients with untreated brain metastases.
Methods
Eligible asymptomatic or symptomatic HER2-positive metastatic BC patients with brain metastases controlled by mannitol and dexamethasone, who were not previously treated with brain radiotherapy (WBRT) or stereotactic radiation therapy (SRT), were included in this study. All patients received 400mg pyrotinib once per day plus 1000 mg/m2 capecitabine twice per day for 14 days and no drug for 7 days. Treatment was given orally. The primary endpoint was the proportion of patients with an objective CNS response (Evaluation Criteria in Solid Tumors (RECIST), version 1.1). All responses had to be confirmed 6 weeks after the initial response.
Results
A total of 61 patients, among whom 52 (85.2%) were assessable for efficacy were enrolled in this study between Jan, 29, 2018, and Apr, 26, 2020. Thirty-nine (75%) patients had an objective CNS response (95% CI 61.1·–86·0); the intracranial and extracranial objective response rate was 78.8% (95% CI 65.3·–88.9). The most common treatment-related grade 3 or grade 4 toxicity was diarrhea (8 cases, 15.4%), leukopenia (4 cases, 7.7%), and hand-foot syndrome (2 cases, 3.8%); no treatment was discontinued because of toxicity.
Conclusions
Pyrotinib plus capecitabine resulted as an effective and safe treatment option for asymptomatic HER2-positive BC patients with low-volume brain metastases who were not treated with radiotherapy.
Clinical trial identification
NCT03691051.
Editorial acknowledgement
Legal entity responsible for the study
The authors.
Funding
Has not received any funding.
Disclosure
All authors have declared no conflicts of interest.