A clinical trial to investigate immunotherapy (IMO-2125) in the skin of patients with a melanoma which is at least 2 millimeters thick

INTERVENTION: In the treatment arm, patients will be intradermally injected with 8 mg IMO‐2125, in 1 mL saline (0.9% sodium chloride) one week prior to sentinel node biopsy (SNB). In the placebo control arm, patients will be intradermally injected with 1 mL plain saline (0.9% sodium chloride) only one week prior to SNB. CONDITION: Melanoma, Immune therapy, Early‐stage melanoma ; ; PRIMARY OUTCOME: The rate of tumor positive sentinel lymph nodes (SLN) SECONDARY OUTCOME: 1) Frequency and activation state of lymph node resident (LNR) conventional dendritic cells (DC) and melanoma antigen‐specific T cell responses in the SLN and peripheral blood. ; ; 2) RFS ; ; 3) OS ; INCLUSION CRITERIA: 1. Patients must be willing and able to sign the informed consent and comply with the study protocol. 2. Must be =18 years of age. 3. Histologically confirmed primary malignant melanoma cutis with a Breslow tumor depth >2.0 mm 4. WHO Performance Status =1. 5. Women of childbearing potential and fertile men must agree to use effective contraceptive methods from screening until at least 90 days after the IMO‐2125 administration.