Evaluating the Efficacy of Disitamab Vedotin in Combination with RC148 Compared to Albumin-bound Paclitaxone Monotherapy or in Combination with Toripalimab for Subjects with HR-negative, HER2-low Expressing Unresectable Locally Advanced or Metastatic Breast Cancer
Voluntarily agree to participate in the study and sign the informed consent form
Stage III unresectable locally advanced or Stage IV metastatic breast cancer.
Subjects must be willing and able to provide a tumor tissue block and/or unstained pathology slides, with priority given to the most recent metastatic lesions that have not previously been subjected to radiotherapy. If this is not feasible or available, then a tumor tissue block (or fresh tissue sections) obtained from locally recurrent lesions should be provided. Freshly obtained tissue is preferred over archived tissue. The provided tissue will be used for biomarker testing and must be suitable for analysis of HER2 expression and PD-L1 expression
Invasive breast tumor tissue has been confirmed as HER2 low expression by the central laboratory
Having previously received anti-HER2 treatment, including ADC (Antibody-Drug Conjugates).
Having previously received immunotherapy, including anti PD-(L)1 or anti PD-(L)2 drugs, or drugs that directly target another stimulatory or co-inhibitory T-cell receptor (such as CD137, CTLA-4, OX-40) during the locally advanced or metastatic stage (except if the last administration was ≥12 months prior to recurrence or progression, using [neo]adjuvant anti PD-(L)1).
Use of investigational drugs or undergoing major surgery within 4 weeks prior to the first dose of study medication
Received or plan to receive live vaccines or attenuated live vaccines within 4 weeks prior to the first dose of study medication or during the study period