Phase 1/​2 Study of Intratumoral Injection of STX-001 in Advanced Solid Tumors as Monotherapy or in Combination With Pembrolizumab

• Biological: STX-001
• Biological: Keytruda®

General Inclusion Criteria:

• ≥ 18 years of age at the time of screeningtesting for cancer or conditions that can lead to cancer before symptoms appear, also known as cancer screening.
• Mentally competent and able to understand and sign the informed consenta process in which a patient receives detailed information about a procedure or treatment, including its potential risks, benefits, and alternatives. The patient then has the opportunity to understand the information and voluntarily agree to the procedure or treatment. form (ICF).
• Eastern Cooperative Oncologythe study, diagnosis and treatment of cancer Group (ECOG) performance status of 0 or 1.
• Life expectancy of ≥ 12 weeks per the Investigator.
• Body weight ˃ 40 kg.
• At least 4 weeks from any prior major surgerytreatment involving removal of cancerous tissue and/or tumours and a margin of healthy tissue around it to reduce recurrence.
• Willing and able to provide bloodthe red bodily fluid that transports oxygen and other nutrients around the body samples prior to the start of this study.
• Has a tumor lesion amenable to injection, must be accessible for pre and post injection biopsyremoval of a section of tissue to analyse for cancer cells, and the patient must be willing to consent to biopsy, if deemed safe by the Investigator.
• Laboratory values (Hematology): Absolute neutrophil count ≥ 1,000 cellsthe basic structural and functional unit of all living things/mm3; Platelet count ≥ 75,000 cells/mm3; Hemoglobin ≥ 8.0 g/dL.
• Laboratory values (Renal): Serum creatinine < 1.5 × upper limit of normal (ULN) or creatinine clearance ≥ 40 mL/min based on the Cockcroft-Gault glomerular filtration rate estimation
• Laboratory values (Coagulation): Prothrombin/International Normalized Ratio (PT/INR) or prothrombin time must be < 1.5 × ULN;
• Activated partial thromboplastin time (aPTT) ≤ 1.5 × ULN unless undergoing anticoagulation therapy.
• Laboratory values (Liver): Aspartate aminotransferase (AST) and alanine aminotransferase (ALT) < 2 × ULN; Bilirubin ≤ 2 × ULN or ≤ 5 × ULN with liver metastasiswhen the cancer has spread to other parts of the body, also known as mets.

Phase 1 Inclusion Criteria:

• Histologically or cytologically documented, locally advanced, or metastatic solid tumor.
• Disease progression confirmed by imagingtests that create detailed images of areas inside the body or other objective evidence after having received standard treatment or patients with refractory solid tumors. Patients must have progressed or are intolerant of at least one line of prior therapy.

Phase 2 Inclusion Criteria (TNBC):

• Histologically or cytologically documented findings consistent with TNBC not amenable to curative surgery, radiation, or other therapy.
• Prior treatment (for advanced, metastatic or [neo]adjuvant) should have included a taxane and/or anthracycline-based therapy and, where appropriate, an approved checkpoint inhibitor.
• Has disease other than the injected lesion that is measurable by RECIST 1.1.

Phase 2 Inclusion Criteria (melanomaa type of cancer that develops from melanocytes, which are the cells that produce pigment generally in the skin (but can develop in other areas of the body)):

• Histologically or cytologically documented findings consistent with advanced melanoma not amenable to curative surgery, radiation, or other therapy. Uveal melanoma is excluded.
• Patients who are not candidates for or have refused available therapies are also eligible.
• Received an anti-programmed death-1 (PD-1) / programmed death ligand-1 (PD-L1) inhibitor as monotherapy or in combination with anti-cytotoxic lymphocyte associated protein 4 (CTLA-4) inhibitor and have either primary or secondary checkpoint inhibitor resistance as per Society for Immunotherapya treatment that uses a person's immune system to fight cancer of Cancera disease where abnormal cells split without control and spread to other nearby body tissue and/or organs (SITC) consensus definition, unless deemed intolerable by the investigator. Patients with BRAF V600E mutant melanoma should have received a BRAF inhibitor as monotherapy or in combination with other targeted agents (mitogen-activated protein kinase [MAPK] kinase [MEK] inhibitors), unless deemed intolerable by the investigator.
• Has disease other than the injected lesion that is measurable by RECIST 1.1.