In phase Ia, the safety and tolerability of BL-B01D1 in patients with unresectable locally advanced or metastatic breast cancer and other solid tumors. investigated to determine the dose-limiting toxicity (DLT), and maximum tolerated dose (MTD) of BL-B01D1.~In phase Ib, the safety and tolerability of BL-B01D1 at the phase Ia recommended dose will be further investigated, and recommended phase II dose (RP2D) for phase II clinical studies will be determined The preliminary efficacy, pharmacokinetic characteristics, and immunogenicity of BL-B01D1 in patients with locally advanced or metastatic solid tumors will be evaluated.~EGFR and/or HER3 protein expression or gene amplification in tumor pathological tissues will be detected, and the expression of related ligand will be explored to study its correlation with the validity index of BL-B01D1, and the biomarkers will be optimized to further study the correlation between selected biomarkers and initial efficacy.
In this study, the dose-limiting toxicity (DLT), maximum tolerated dose (MTD), recommended phase II dose (RP2D), the preliminary efficacy, pharmacokinetic characteristics, and immunogenicity of BL-B01D1 will be investigated in patients with unresectable locally advanced or metastatic breast cancer and other solid tumors.