A Study Comparing GSK2118436 to Dacarbazine (DTIC) in Previously Untreated Subjects With BRAF Mutation Positive Advanced (Stage III) or Metastatic (Stage IV) Melanoma

Inclusion Criteria:

- Adults at least 18 years of age

- Has advanced (unresectable Stage III) or metastatic (Stage IV) melanoma that is BRAF
mutation positive (V600E)

- Is treatment naive for advanced (unresectable) or metastatic melanoma, with the
exception of Interleukin 2 (IL-2) which is allowed.

- Has measurable disease according to RECIST 1.1 criteria.

- Women of child-bearing potential must have a negative pregnancy test within 14 days
prior to the first dose of study treatment.

- Women with reproductive potential must be willing to practice acceptable methods of
birth control during the study and for up to 4 weeks after the last dose of study
medication.

- Men with reproductive potential must be willing to practice acceptable methods of
birth control during the study and for up to 16 weeks after the last dose of study
medication.

- Must have adequate organ function.

- Must have Eastern Cooperative Oncology Group (ECOG) Performance Status of 0-1.

Exclusion Criteria:

- Currently receiving cancer therapy (chemotherapy, radiation therapy, immunotherapy,
biologic therapy or surgery).

- Evidence of active central nervous system (CNS) disease.

- Previous treatment for metastatic melanoma, including treatment with BRAF or MEK
inhibitor.

- A history of other malignancy. Subjects who have been disease-free for 5 years or
subjects with a history of complete resected non-melanoma skin cancer or successfully
treated in situ carcinoma are eligible.

- History of Human Immunodeficiency Virus (HIV) infection.

- Certain cardiac abnormalities