An Open-Label, Multi-Center Study to Investigate the Objective Response Rate, Safety, and Pharmacokinetics of GSK1120212, a MEK Inhibitor, in BRAF Mutation-positive Melanoma Subjects Previously Treated With or Without a BRAF Inhibitor

Inclusion Criteria:

- Metastatic cutaneous melanoma that was previously treated with: (Cohort A) a BRAF
inhibitor either with or without other prior therapy. (Cohort B) at least 1 prior
chemotherapy or immunotherapy, without treatment with a BRAF inhibitor.

- Documented positive BRAF mutation (V600E, V600K, or V600D).

- Subjects must provide archived tumor tissue or undergo fresh tumor biopsy prior to
enrollment.

- The subject must have a radiographically measurable tumor.

- The subject is able to carry out daily life activities without significant difficulty
(ECOG performance status score of 0 or 1).

- Able to swallow and retain oral medication.

- Sexually active subjects must use acceptable methods of contraception during the
course of the study.

- Adequate organ system function and blood cell counts.

Exclusion Criteria:

- The subject has had major surgery or received certain types of cancer therapy within
21 days before starting the study.

- Previous treatment with a MEK inhibitor.

- Current use of a prohibited medication listed in the protocol.

- Uncontrolled glaucoma.

- Brain metastasis, unless previously treated with surgery or stereotactic
radiosurgery, and the disease has been stable for at least 2 months prior to
enrollment.

- Current severe or uncontrolled systemic disease.

- History of clinically significant heart, lung, or eye/vision problems.

- Significant unresolved side effects from previous anti-cancer therapy.

- The subject is pregnant or breastfeeding.