Eligible patients (ECOG 0-1) must have advanced solid tumors refractory to standard therapy (Phase 1: all types; Phase 2: selected indications). Prior TROP2-directed therapy is allowed. Key requirements: measurable disease (RECIST 1.1/RANO-BM), archival/pretreatment biopsy, and adequate organ function (ANC ≥1.5×10⁹/L, platelets ≥100×10⁹/L, Hb ≥9 g/dL, AST/ALT ≤2.5×ULN). Exclusions: active/progressing CNS metastases (unless stable for ≥1 month post-treatment without steroids >4 mg dexamethasone), unresolved Grade >1 toxicities (except alopecia/vitiligo), recent systemic therapy (within 4 weeks/5 half-lives), or high-dose steroids (>10 mg prednisone/day).

The study assesses the safety of LCB84 monotherapy and combination therapy with anti-PD-1 antibodies over 48 months by monitoring AEs/SAEs. The recommended Phase 2 dose is determined within 24 months based on tolerability, PK data, and preliminary anti-tumor activity. Efficacy endpoints-ORR, clinical benefit rate (CBR), DOR, TTP, PFS, and OS-are evaluated over 24 months via RECIST 1.1, iRECIST, and RANO-BM criteria.