BRF116056 is the first clinical experience with GSK2118436, a BRAF inhibitor, in Japan. This study will be designed to assess safety, tolerability, single and repeat dose PK profile and preliminary efficacy of GSK2118436 in Japanese subjects with BRAF V600 mutation positive solid tumors using continuous daily dosing schedule.

BRF116056 is the first clinical experience with GSK2118436, a BRAF inhibitor, in Japan. This study will be designed to assess safety, tolerability, single and repeat dose PK profile and preliminary efficacy of GSK2118436 in Japanese subjects with BRAF V600 mutation positive solid tumors using continuous daily dosing schedule. Dose escalation of GSK2118436 will be performed according to a standard 3+3 dose-escalation design. GSK2118436 is given twice a day. However, to characterize the PK of GSK2118436 and its metabolites after single-dose administration, GSK2118436 will NOT be administrated for a week after the first administration. GSK2118436 continuous dosing will start after the 168-hour PK sample is obtained. Subjects may receive study treatment until disease progression, death or an unacceptable adverse event.

Inclusion Criteria:

• Histologically or cytologically confirmed diagnosis of a solid tumor that is not responsive to standard therapies or for which there is no approved or curative therapy.
• Subjects must have BRAF V600E or K mutant positive tumors.
• 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).
• Use of an investigational anti-cancer drug within 28 days preceding the first dose of GSK2118436.
• 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.
• Pregnant or lactating female.