Single-center phase 2 trial of brain radiotherapy combined with pyrotinib and capecitabine for brain metastases from HER2-positive breast cancer

The potential benefit of combining intracranial effective systemic therapy with radiotherapy for patients with breast cancer with brain metastases (BCBMs) is not clear. A phase 2 trial at Fudan University (Shanghai, China) evaluated the combination of either fractionated stereotactic radiotherapy or whole-brain radiotherapy with pyrotinib and capecitabine for HER2-positive BCBMs. The one-year CNS PFS rate (primary end point) was 74.9% with median CNS PFS 18.0 months. The one-year PFS rate was 66.9% , and the median PFS was 17.6 months, while the median OS was not reached. The CNS ORR was 85%. The most common grade 3 or 4 treatment-related adverse event was diarrhea (7.5% of patients), while asymptomatic radiation necrosis was identified in6% of lesions treated with SRS. Most patients maintained neurocognitive function. The authors conclude that radiotherapy combined with pyrotinib and capecitabine is associated with long-term intracranial progression-free survival among patients with HER2-positive BCBMs.