T-DXd With or Without Neratinib for HER2 Positive Breast Cancer With Brain Metastasis

This study is a prospective, multicenter, open-label, Phase II, randomized controlled clinical trial aimed at evaluating the efficacy and safety of T-DXd with or without neratinib in patients with HER2-positive breast cancer with brain metastases. All eligible subjects will be randomly assigned in a 1:1 ratio across multiple centers in China to receive either T-DXd combined with neratinib or T-DXd monotherapy until extracranial progression as defined by RECIST 1.1, unless unacceptable toxicity occurs, consent is withdrawn, or other criteria for discontinuation are met.