SI-B036-ST-101 in Advanced/Metastatic Solid Tumors

Prior treatment

• Chemotherapy, biological therapy, immunotherapy, targeted therapy (including small molecule inhibitor of tyrosine kinase), and other antitumor therapy within 4 weeks or 5 half-lives (whichever is shorter) prior to the first administration; radical radiotherapy, major surgery within 4 weeks prior to the first administration; mitomycin and nitrosoureas treatment within 6 weeks prior to the first administration; oral drugs such as Ticio such as capecitabine, or palliative radiotherapy within 2 weeks prior to initial administration.
• Received systemic immunostimulatory therapy within 4 weeks prior to the first dose or is still within 5 half-lives of the treatment (whichever is longer).
• Received immunosuppressive drugs within 2 weeks prior to the first dose. The use of topical, inhaled, and locally injected steroids is permitted.
• Participants with history of severe heart disease within 6 months before enrollment.
• Other malignant tumors were diagnosed within 5 years prior to the first administration.
• Participants with a thromboembolic event (eg, deep vein thrombosis \[DVT\] or pulmonary embolism \[PE\]), stroke, or transient ischemic attack (TIA) within 6 months before screening.
• Active autoimmune diseases and inflammatory diseases. For autoimmune conditions that are active but stable and low-grade on systemic therapy, discussion with the medical monitor is required prior to screening.
• Participants with advanced/clinically significant lung diseases, who have a history of noninfectious interstitial lung disease (ILD)/pneumonitis that required treatment with steroids, have current ILD/pneumonitis, or where suspected ILD/pneumonitis cannot be ruled out by imaging at screening, or concurrent pulmonary disease resulting in severe impaired respiratory function.
• Participants with primary tumors in the central nervous system (CNS), active or untreated CNS metastases or carcinomatous meningitis should be excluded. Participants with previously treated brain metastases may participate provided they are clinically stable for at least 4 weeks and have no evidence of new or enlarging brain metastases and no requirements for corticosteroids 14 days prior to Screening.
• Previous organ transplantation or allogeneic hematopoietic stem cell transplantation.
• Subjects with recent surgery, biopsy, or invasive procedures without adequate wound healing prior to study enrollment.
• Participated in another clinical trial within 4 weeks prior to first dose of study treatment.
• History of fistula, gastrointestinal perforation, or abdominal abscess within 6 months prior to the first dose.

Other illness

• For the dose escalation portion of the study only, participants with a primary diagnosis of lung cancer are excluded.
• Participants with a history of anaphylaxis or severe hypersensitivity reactions.
• Other conditions that the Investigator or sponsor believes are not suitable for participating in this clinical trial.

Lab values

• Participants with prolonged QT interval (QTcF \>470 msec), complete left bundle branch block, Grade 3 atrioventricular block, or a history of additional risk factors for Torsades de Pointes (TdP) or any current concomitant medication known to prolong the QT/QTc interval or cause TdP.
• Participants with active or recent clinically significant bleeding are excluded, or who are at risk of bleeding due to clinically significant platelet abnormalities or coagulopathy, or who require full-dose anticoagulation or high-intensity antiplatelet therapy on high dose nonsteroidal anti-inflammatory drugs (NSAIDs).

Other

• Participant with active or untreated hemorrhagic CNS lesions.
• Participants who are pregnant, breastfeeding, or planning to become pregnant during the study.
• Participant with moderate or major hemoptysis history.
• Participant has tumors invading large blood vessels

• Documented locally advanced or metastatic solid tumor(s) not amenable to curative surgery or radiation and have received at least 1 line of standard therapy, including adjuvant/neoadjuvant treatment, or whose cancer is considered refractory to the standard of care (SOC) or for which no standard treatment is available.
• Toxicity of previous antitumor therapy has returned to level ≤1 as defined by National Cancer Institute (NCI) Common Terminology Criteria for Adverse Events (CTCAE) V6.0.
• Has no serious cardiac dysfunction and left ventricular ejection fraction ≥50%.
• Has adequate organ function before enrollment
  • PART C Additional Inclusion Criteria (Dose Expansion Only)
  • \- For immuno-oncology (IO)-exposed non-small cell lung cancer (NSCLC): histologically or cytologically confirmed unresectable locally advanced or metastatic non-small cell lung cancer (NSCLC) in subjects who are previously exposed to immune checkpoint inhibitor (ICI) therapy (IO-exposed) and whose disease is refractory to standard of care (SOC) therapy or for whom no appropriate standard treatment options are available. In addition, subjects must have received at least one prior line of platinum therapy.
  • For IO naïve NSCLC: histologically or cytologically confirmed unresectable locally advanced or metastatic NSCLC in subjects who are not previously exposed to ICI therapy. Subjects must also have PD-L1 expression ≥1% (tumor proportion score \[TPS\]) as determined by an FDA-approved assay. In addition, subjects must have received at least one prior line of platinum therapy.
  • For Melanoma: histologically confirmed unresectable or metastatic melanoma with prior treatment with an immune checkpoint inhibitor regimen and documented disease progression following such therapy.
  • For Ovarian Cancer: has histologic documentation of epithelial ovarian, primary peritoneal, or fallopian tube cancer that has progressed or relapsed on or after a previous chemotherapy with or without a poly (ADP-ribose) polymerase (PARP) inhibitor. Prior bevacizumab treatment is allowed.