Assess Safety, Tolerability, Pharmacokinetics, and Preliminary Efficacy of BAT8009

Inclusion Criteria: 1. Able to give voluntary informed consent and understand the study and are willing to follow and complete all the study required procedures. 2. Aged ≥ 18 years and ≤ 75 years. 3. Life expectancy ≥ 3 months. 4. ECOG performance status ≤ 1. 5. Histologically/cytologically confirmed, locally advanced unresectable or metastatic solid tumours that are refractory to standard therapy. 6. Has measurable or evaluable disease per RECIST v1.1. 7. Adequate haematological, liver, kidney, cardiac and coagulation function. 8. Is willing to provide pre-existing diagnostic or resected tumour samples (if available). 9. Female patients must: Be of non-child-bearing potential; Male patients must: be willing not to donate sperm. 10. Must agree to adhere to the current state and national advice regarding minimising exposure to COVID-19 from the first Screening visit until the end of study (28-day Safety Follow-up Visit). Exclusion Criteria: 1. Females who are pregnant or nursing. 2. Receiving concurrent anticancer therapy or investigational therapy. 3. Persisting AEs that are \> Grade 1 from prior antitumour treatment as per CTCAE v5.0. 4. Patients with primacy central nervous system (CNS) malignancy, symptomatic CNS metastases, meningeal metastases or leptomeningeal disease are not allowed. 5. Had major surgery within 28 days of the Screening visit. 6. History of autologous transplantation ≤ 3 months. 7. History of severe infection deemed clinically significant by the PI or designee within 4 weeks. 8. History of human immunodeficiency virus (HIV) infection. 9. Active hepatitis B or C. 10. History of a Grade 3 or Grade 4 allergic reaction to treatment with other antibodies.