Study to Compare Pharmacokinetics, Efficacy, Safety, and Immunogenicity of MB11 Versus EU-/US-Opdivo® in Subjects With Previously Untreated Advanced [Unresectable or Metastatic] Melanoma

This is a randomised, multicentre, multinational, double-blind, integrated study to sompare the pharmacokinetics, efficacy, safety, and immunogenicity of MB11 versus Opdivo® in subjects with previously untreated advanced (unresectable or Metastatic) Melanoma

Inclusion Criteria: 1. Age ≥18 years at the time of signing the informed consent (or adulthood where the legalage of majority in the country is established \>18 years). 2. Body weight ≥50 kg at baseline. 3. Signed informed consent must be obtained before initiation of any study-specific procedures or treatment. 4. ECOG performance status of 0 or 1. 5. Life expectancy for at least 3 months. 6. Untreated, histologically confirmed advanced unresectable Stage III or Stage IV melanoma, as per AJCC 8th Edition staging system. Prior melanoma systemic therapy for earlier stages is allowed for patients who have been disease-free for at least 1 year after end of therapy, except if therapy included use of prohibited medications. Prior use of immune therapies (adjuvant or neoadjuvant) is not allowed as per Exclusion Criteria #2. 7. At least 1 measurable disease lesion by CT or MRI per RECIST v1.1 criteria. 8. Tumour tissue from an unresectable or metastatic site of disease, collected within 90 days prior to randomisation, must be available and provided for PD-L1 testing. All samples must be classified as PD-L1 positive (≥1% to \90 days is available and there is no possibility of having a new biopsy sample, then the subject will be excluded. 9. In the case of prior palliative radiotherapy (on metastatic lesions), this must have been completed at least 2 weeks prior to the study drug administration. No adjuvant radiation therapies are allowed. 10. Any BRAF mutation status is allowed (BRAF-mutated, BRAF wild-type or non-mutated, or BRAF status unknown). 11. Adequate organ function (bone marrow, hepatic, renal, haematologic, endocrine, and coagulation function) should be demonstrated during the screening period. This is defined as: 1. Haematologic function: absolute neutrophil count ≥1.5 × 109/L, platelets 9≥100 × 10 /L, and haemoglobin ≥9 g/dL. \*\* Subjects should not have received RBC transfusion prior to 14 days beforescreening labs. 2. Renal function: serum creatinine level ≤1.5 × ULN or calculated CrCl ≥60 mL/min (using the Cockcroft-Gault formula). 3. Liver function: total bilirubin level ≤1.5 × ULN (except subjects with Gilbert Syndrome, who can have total bilirubin \