Inclusion Criteria:
* Patient has histologically or cytologically confirmed diagnosis of uveal melanoma metastatic to the liver and is determined to be a candidate for percutaneous hepatic perfusion with melphalan
* The subject has read, signed and dated the Informed Consent Form (ICF), having been advised of the risks and benefits of the trial in a language understood by the subject.
* Age \> 18 years at date of informed consent signature having the ability to comply with the protocol.
* Contrast-enhanced cross-sectional imaging of the abdomen (either CT or MRI) obtained within two months prior to study enrollment
* Measurable metastatic disease. Subject must have at least one site of metastatic disease ≥ 1 cm in size and amenable to percutaneous image-guided biopsy
* Life expectancy \> 12 weeks.
* Eastern Cooperative Oncology Group (ECOG) Performance Status of 0 or 1
* Laboratory requirements:
* Absolute neutrophil count (ANC) \> 1 x 109/L
* Platelets \> 75 x 109/L
* Alanine aminotransferase (ALT) / Aspartate aminotransferase (AST) \< 5 x ULN
* Total bilirubin \<3 mg/dL
* International normalized ratio (INR) \<1.7
* Glomerular filtration rate (GFR) \>30 ml/min
Exclusion Criteria:
* Lesion to undergo biopsy cannot have undergone prior radiation therapy or other locoregional therapy
* Continued adverse events from a previously administered chemotherapeutic agents. Grade 1 adverse events and ongoing toxicities such as alopecia are exempt
* Treatment with systemic corticosteroids exceeding the equivalent of 10 mg/day of prednisone or other systemic immunosuppressive medications (including but not limited to prednisone, dexamethasone, cyclophosphamide, azathioprine, methotrexate, and anti-tumor necrosis factor \[anti-tumor necrosis factor (TNF)\] agents) within 2 weeks prior to Day 1, or anticipated requirement for systemic immunosuppressive medications exceeding the equivalent of 10 mg/day of prednisone during the trial
* Patients who receive acute, low-dose, systemic corticosteroid medications (e.g., a one-time dose of dexamethasone for nausea) or for prevention of hypersensitivity reactions to contrast agents may be enrolled in the trial.
* Anticoagulant or anti-platelet medication that cannot be interrupted prior to biopsy
* Pregnant or lactating
* Any other diseases, metabolic dysfunction, physical examination finding, or clinical laboratory finding giving reasonable suspicion of a disease or condition that contraindicated the use of an investigational drug or that could affect the interpretation of the results or render the patient at high risk from treatment complications.
* Treatment with systemic immunostimulatory agents (including but not limited to interferon(IFN)s, interleukin \[IL\]-2) within 6 weeks or five half- lives of the drug, whichever was shorter, prior to Day 1.
* Treatment with immune checkpoint blockade therapies, including anti-CTLA-4, anti-PD-1, and anti-PD-L1 therapeutic antibodies, anti-LAG-3 antibodies, within the past three months. Prior treatment with tebentafusp is allowed with no washout period required.
* Treatment with any investigational systemic medication within at least one month prior to biopsy. If an investigational agent is an immune checkpoint inhibitor, a three-month washout is required. Prior treatment with Darovasertib and Crizotinib is allowed with no washout period required.
* Signs or symptoms clinically significant of infection within 2 weeks prior to Day 1.