Measurable disease according to Response Evaluation Criteria In Solid Tumors (RECIST) criteria
Performance status: Karnofsky (for participants \>/= 16 years of age) or Lansky (for participants \< 16 years of age) score of \>/= 60
Adequate bone marrow, liver and renal function
Participants must have fully recovered from the acute toxic effects of all prior therapy prior to first administration of study drug
You may not be if
Active or untreated central nervous system (CNS) lesions
History of or known spinal cord compression or carcinomatous meningitis
Anticipated or ongoing administration of anti-cancer therapies other than those administered in this study
Previous malignancy within the past 5 years except for basal or squamous cell carcinoma of the skin, melanoma in-situ, and carcinoma in-situ of the cervix
Previous treatment with selective/specific BRAF or Methyl Ethyl Ketone (MEK) inhibitor (previous treatment with sorafenib is allowed)
Any previous treatment with study drug (RO5185426) or participation in a clinical trial that includes RO5185426
Pregnant or lactating females
Known human immunodeficiency virus (HIV) positivity or acquired immune deficiency syndrome (AIDS)-related illness, active hepatitis B virus, or active hepatitis C virus
