Phase I, open label, dose-escalation, and safety study designed to assess the safety and biologic activity of the investigational agent CBL0137 in combination with standard of care drugs, ipilimumab and nivolumab in sequential cohorts of adult patients with locally advanced and metastatic melanoma who are candidates for immune checkpoint blockade and have tumors accessible for serial biopsies.

The primary objectives will be Initial assessment of safety and tolerability of the combination of CBL0137 with Nivolumab and Ipilimumab.

Inclusion Criteria:

1. Patients must have:

   1. Pathologically proven stage III melanoma with one or more macroscopic lymph node metastases (measurable according to RECIST v. 1.1) amenable to biopsy and/or surgery OR:
   2. Patients considered to have stage III or stage IV disease amenable to serial biopsies as determined by the treating physician. Note: patients with in-transit metastasis may be eligible after surgical consultation if not surgical candidates.
   3. Patients must have disease amenable to and must be willing to undergo protocol-directed repeat biopsies and blood draws.

2. Age > 18 years

3. ECOG performance status 0 or 1

4. Patients must have normal organ and marrow function

Exclusion Criteria:

1. Patients may not be receiving any other investigational agents
2. Patients with a known active autoimmune disease
3. Prior treatment with CTLA-4 or PD1/PD-L1 pathway targeted systemic treatment
4. Concurrent medical condition requiring the use of immunosuppressive medications, or immunosuppressive doses of systemic corticosteroids
5. Patients with ongoing diarrhea (> 4 bowel movements/day) unresolved despite medical and best supportive care in the two weeks preceding therapy