HF158K1 in Patients With HER-2 Expressing Advanced Solid Tumors

Inclusion Criteria: 1. Voluntary to participate and sign ICF. 2. Age ≥ 18 and ≤ 75 years. 3. Unresectable or metastatic advanced solid tumors with HER-2 expression (IHC 3+, 2+, or 1+). 4. ECOG score 0-1. 5. Expected survival ≥ 6 months. 6. At least one measurable lesion per RECIST v1.1. 7. Adequate organ function: ANC ≥ 1.5×10⁹/L, LYM ≥ 1.0×10⁹/L, PLT ≥ 90×10⁹/L, HGB ≥ 8.0 g/dL; APTT ≤ 1.5×ULN, INR ≤ 1.5; TBIL ≤ 1.5×ULN, ALT/AST ≤ 2.5×ULN (≤ 5×ULN if liver metastases); CrCl ≥ 30 mL/min; LVEF ≥ 50%. 8. Agreement to use effective contraception. Exclusion Criteria: 1. Cumulative doxorubicin dose ≥ 350 mg/m² or prior anthracycline-induced cardiotoxicity. 2. Current use of immunosuppressants or systemic corticosteroids (\> 10 mg/day prednisone). 3. Prior anti-tumor therapy \< 2 weeks (4 weeks for nitrosourea/mitomycin C). 4. Symptomatic CNS metastases. 5. Unresolved AEs from prior therapy \> Grade 1. 6. Serious cardiovascular diseases (thromboembolic events within 3 months, NYHA III-IV, ACS within 6 months, or uncontrolled hypertension). 7. Active infection or unexplained fever \> 38.5°C. 8. HIV, active HBV or HCV. 9. Pregnant or breastfeeding.