A Study of SI-B036 in Patients With Locally Advanced or Metastatic Urological Tumors and Other Solid Tumors

The study consists of two phases: a dose-escalation phase (Phase Ia) and a dose-expansion phase (Phase Ib).

Inclusion criteria

• Voluntarily sign the informed consent form and agree to comply with the protocol requirements;
• No gender restriction;
• Age: ≥ 18 years and ≤ 75 years;
• Expected survival time ≥ 3 months;
• Locally advanced or metastatic urological tumors and other solid tumors;
• Agree to provide archived tumor tissue specimens collected within 2 years from the primary or metastatic lesion, or fresh tissue samples;
• Must have at least one measurable lesion as defined by RECIST v1.1;
• Eastern Cooperative Oncology Group (ECOG) performance status score of 0 or 1;
• Toxicities from prior anti-tumor therapy must have recovered to ≤ Grade 1 as defined by NCI-CTCAE v6.0;
• No severe cardiac dysfunction, with left ventricular ejection fraction (LVEF) ≥ 50%;
• Organ function levels must meet the specified requirements;
• Coagulation function: International Normalized Ratio (INR) ≤ 1.5, and activated partial thromboplastin time (aPTT) ≤ 1.5 × upper limit of normal (ULN);
• Urine protein ≤ 1+ or ≤ 1000 mg/24h;
• For premenopausal women of childbearing potential, a serum pregnancy test must be performed within 7 days prior to the start of treatment, with a negative result, and they must not be breastfeeding; all enrolled patients (regardless of male or female) must use adequate barrier contraception throughout the entire treatment period and for 6 months after the completion of treatment;
• The trial participant must be willing and able to comply with the visit schedule, treatment plan, laboratory tests, and other study-related procedures as specified in the protocol.

Exclusion criteria

• Use of chemotherapy, biotherapy, immunotherapy, or similar treatments within 4 weeks or 5 half-lives prior to the first dose;
• Receipt of immunosuppressive therapy within 2 weeks prior to the first dose;
• History of severe cardiac or cerebrovascular disease;
• Prolonged QTc interval, complete left bundle branch block, third-degree atrioventricular block, or frequent and uncontrolled arrhythmias;
• Active autoimmune diseases and inflammatory diseases;
• Prior history of ≥ Grade 3 toxicity related to anti-angiogenic therapy when receiving such treatment previously;
• Diagnosis of another solid tumor within 5 years prior to the first dose;
• Unstable thrombotic events requiring therapeutic intervention within 6 months prior to the first dose;
• Uncontrolled hypertension;
• Diabetes mellitus with poor glycemic control;
• History of interstitial lung disease (ILD) requiring corticosteroid therapy, or current ILD, or ≥ Grade 2 radiation pneumonitis;
• Concurrent pulmonary disease resulting in severe impairment of respiratory function;
• Active central nervous system (CNS) metastases;
• History of hypersensitivity to recombinant humanized antibodies or human-mouse chimeric antibodies, or allergy to any excipient of SI-B036;
• Prior history of organ transplantation or allogeneic hematopoietic stem cell transplantation (Allo-HSCT);
• Positive for human immunodeficiency virus (HIV) antibodies, active tuberculosis, active hepatitis B virus infection, or active hepatitis C virus infection;
• Active infection requiring systemic therapy within 4 weeks prior to the first dose of the study drug;
• Presence of pleural, abdominal, or pelvic effusion, or pericardial effusion requiring drainage and/or associated with symptoms within 4 weeks prior to the first dose of the study drug;
• Imaging findings indicating that the tumor has invaded or encased the great thoracic vessels, pericardium, or heart;
• Subjects with clinically significant bleeding or obvious bleeding tendency within 4 weeks prior to screening;
• History of fistula, gastrointestinal perforation, or intra-abdominal abscess within 6 months prior to the first dose;
• Use of another investigational drug within 4 weeks or 5 half-lives prior to the first dose;
• Pregnant or lactating women;
• Other conditions that, in the investigator's opinion, make the subject unsuitable for participation in this clinical trial.