Aims to Explore the Safety, Tolerability, and Preliminary Efficacy of SCTB41 in Adult Patients with Advanced Malignant Solid Tumours.

Inclusion criteria

• Voluntarily sign the informed consent form (ICF);
• Male or female, ≥18 years old;
• Survival duration more than 3 months;
• ECOG score ≤ 1 point;
• Participants in Phase Ia (dose-escalation phase) are required to meet the following criteria: histologically or cytologically confirmed diagnosis of advanced malignant solid tumour;
• Participants in Phase Ib (dose-expansion phase) and Phase II are required to meet the following criteria: Histologically or cytologically confirmed specific type advanced malignant solid tumours;
• Adequate organ and bone marrow function.

Exclusion criteria

• Participants with brainstem, meningeal, spinal metastases, orcompression; active central nervous system metastases;
• Other malignancies diagnosed;
• History of hypertensive crisis or hypertensive encephalopathy; presence of uncontrolled hypertension. History of arterial thrombosis or deep veinthrombosis within 6 months prior to enrollment;
• Presence of any active autoimmune disease or a history of autoimmunedisease with an expected recurrence;
• Received chemotherapy, immunotherapy, biologic therapy, or other antitumor treatments within 4 weeks before enrollment;
• Need for immunosuppressive drugs within 2 weeks prior to enrollment oranticipated during the study;
• Significant coagulopathy or other evident risk of bleeding;
• uncontrolled effusions in the serous cavities within 4 weeks before enrollment；
• Major surgery or significant trauma within 4 weeks prior to enrollment;presence of unhealed skin wounds, surgical sites, trauma sites, severe- Page 3 of 4 [DRAFT] -mucosal ulcers, or fractures, or if the Investigator deems the participantunsuitable for the study;
• History of permanent discontinuation of immunotherapy due to immunerelated toxicity or occurrence of ≥ Grade 3 irAEs;
• Known severe allergy to similar antibody drugs;
• Presence of active infection；
• History of organ transplantation or stem cell transplantation;
• Pregnant or breastfeeding female; women of childbearing potential withpositive pregnancy test within 7 days before the enrollment; participants(including males of childbearing potential and their female partners, and females of childbearing potential and their male partners) unwilling to use medically recognized effective contraception during the study and for 6 months after treatment ends.