Study on Intravenous STX-003 for Advanced Solid Tumors, Alone or with Pembrolizumab

Inclusion Criteria

• Must be able to understand and sign a consent form.
• Have a type of cancer that can be treated with FDA-approved PD-1/L1 therapies, like certain types of melanoma or lung cancer.
• Have advanced or metastatic solid tumors confirmed by lab tests.
• Have at least one tumor that can be measured by scans.
• Have no other curative treatment options or have refused standard treatments.
• Be in good general health with a performance status of 0 or 1.
• Have a life expectancy of at least 12 weeks.
• Be 18 years or older and weigh at least 40 kg.
• Agree to use birth control during the study and for 3 months after the last dose.
• Willing to follow study procedures and attend all appointments.
• Meet specific blood and organ function criteria, including adequate blood cell counts and liver and kidney function.
• For Phase 2, specific criteria for lung cancer and melanoma apply, such as having certain biomarkers or previous treatments.

Exclusion Criteria

• Have a history of immune deficiency or significant autoimmune disease needing treatment in the last 6 months.
• Have had severe immune-related side effects from previous treatments that haven't improved.
• Have had a solid organ transplant and are on immunosuppressive drugs.
• Have recent heart problems, like a heart attack or heart failure.
• Have active infections needing IV antibiotics or uncontrolled bleeding.
• Have untreated or active brain tumors or metastases.
• Have another untreated cancer, except for certain skin or bladder cancers.
• Have had major surgery within 4 weeks before starting the study.
• Have received certain treatments, like STX-003 or live vaccines, recently.
• Are pregnant, breastfeeding, or planning to become pregnant soon.
• Have a history of lung disease or psychiatric disorders that could affect participation.