Inclusion Criteria:

          1. Histologically confirmed unresectable or metastatic melanoma as per American Joint
             Committee on Cancer (AJCC) staging system

          2. Equal or greater than 18 years of age

          3. Eastern Cooperative Oncology Group (ECOG) performance status of 0 or 1

          4. Patient willing and able to provide written informed consent.

          5. Treatment naïve (no prior systemic therapy for unresectable or metastatic melanoma).
             Note that prior adjuvant or neoadjuvant melanoma therapy (except anti-PD1 and/or
             anti-CTLA-4 therapy) is permitted if it was completed at least 6 weeks prior to
             allocation, and all related adverse events have either returned to baseline or
             resolved.

          6. Willing and able to comply with scheduled visits, treatment schedule, laboratory
             testing, and other requirements of the study.

          7. Measurable disease by CT or MRI per RECIST 1.1 criteria.

          8. At least 2 weeks since the completion of prior therapy, including surgery or
             radiotherapy.

          9. Screening laboratory values must meet the following criteria and should be obtained
             within 14 days prior to randomisation/registration

         10. Women of childbearing potential (WOCBP) must use appropriate method(s) of
             contraception. WOCBP should use an adequate method to avoid pregnancy for 23 weeks (30
             days plus the time required for nivolumab to undergo five half-lives) after the last
             dose of investigational drug.

         11. Women of childbearing potential must have a negative serum or urine pregnancy test
             (minimum sensitivity 25 IU/L or equivalent units of HCG) within 72 hours prior to the
             start of treatment.

         12. Men who are sexually active with WOCBP must use any contraceptive method with a
             failure rate of less than 1% per year. Men receiving nivolumab and who are sexually
             active with WOCBP will be instructed to adhere to contraception for a period of 31
             weeks after the last dose of investigational product. Women who are not of
             childbearing potential (i.e., who are postmenopausal or surgically sterile as well as
             azoospermic men do not require contraception.

         13. Patients must agree to have archival tumour material collected. This can either be
             from a resected lymph node, primary melanoma or metastatic site. Where possible the
             most recently acquired tumour specimen should be provided. If archival tumour tissue
             is not available, subjects must consent to allow the acquisition of additional tumour
             tissue prior to trial entry.

         14. Patient enrolled on the biopsy cohort must be agreeable to have serial tumour biopsies
             during the study.

        Exclusion Criteria:

          1. Patients are excluded if they have ever had any brain or leptomeningeal metastases.

          2. Prior exposure to a CTLA-4 inhibitor (e.g. ipilimumab, tremelimumab), PD-1 inhibitor
             (e.g. nivolumab, pembrolizumab), PD-L1 inhibitor (e.g. MEDI-4736), PD-L2 inhibitor or
             any or any other antibody or drug specifically targeting T-cell costimulation or
             immune checkpoint pathways.

          3. Prior systemic treatment with a BRAF and/or MEK inhibitor.

          4. Prior treatment with denosumab.

          5. Prior malignancy active within the previous 2 years except for locally curable cancers
             that have been apparently cured, such as basal or squamous cell skin cancer,
             superficial bladder cancer or carcinoma in situ of the cervix or breast.

          6. Life expectancy of less than or equal to 6 months.

          7. Prior history or current evidence of osteonecrosis/osteomyelitis of the jaw.

          8. Active dental or jaw condition, which requires oral surgery, including tooth
             extraction.

          9. Non-healed dental/oral surgery.

         10. Surgery, or radiotherapy within less than 2 weeks of Cycle 1 Day 1. Any clinically
             relevant sequelae from the surgery or radiotherapy must have improved to grade 1 prior
             to Cycle 1 Day 1.

         11. Uncontrolled intercurrent illness including, but not limited to, ongoing or active
             infection, symptomatic congestive heart failure, unstable angina pectoris, cardiac
             arrhythmia, or psychiatric illness/social situations that would limit compliance with
             study requirements.

         12. Patients should be excluded if they have an active, known or suspected autoimmune
             disease.Subjects are permitted to enrol if they have vitiligo, type I diabetes
             mellitus, residual hypothyroidism due to autoimmune condition only requiring hormone
             replacement, psoriasis not requiring systemic treatment, or conditions not expected to
             recur in the absence of an external trigger

         13. Patients should be excluded if they have a condition requiring systemic treatment with
             either corticosteroids (> 10 mg daily prednisone equivalents) or other
             immunosuppressive medications within 14 days of study drug administration. Inhaled or
             topical steroids and adrenal replacement doses > 10 mg daily prednisone equivalents
             are permitted in the absence of active autoimmune disease.

         14. Any investigational drug or other systemic drug therapy for melanoma within 28 days or
             5 half-lives from baseline.

         15. Pregnant or breastfeeding females.

         16. Patients should be excluded if they are positive test for hepatitis B virus surface
             antigen (HBV sAg) or hepatitis C virus ribonucleic acid (HCV antibody) indicating
             acute or chronic infection.

         17. Patients should be excluded if they have known history of testing positive for human
             immunodeficiency virus (HIV) or known acquired immunodeficiency syndrome (AIDS).

         18. Allergies and Adverse Drug Reaction

               1. History of allergy to study drug components.

               2. History of severe hypersensitivity reaction to any monoclonal antibody.

         19. Patients with symptomatic or impending cord compression unless appropriately treated
             beforehand and clinically stable.

         20. Use of any vaccines against infectious diseases (e.g., influenza, varicella, etc.)
             within 3 weeks (21 days)of initiation of study therapy.