A Study on the Effect of Vemurafenib on the Pharmacokinetics of a Single Dose of Tizanidine in Patients With BRAFV600 Mutation-Positive Metastatic Malignancies

Inclusion Criteria: * Adults 18 to 70 years of age, inclusive * Unresectable Stage IIIc or IV metastatic melanoma positive for the BRAFV600 mutation or other malignant tumor type which harbors a V600 activating mutation of BRAF, as determined by Cobas 4800 BRAFV600 Mutation Test or a DNA sequencing method * Eastern Cooperative Oncology Group (ECOG) performance status 0 to 2 * Life expectancy greater than or equal to (\>/=) 12 weeks * Participant has not consumed tobacco or nicotine-containing products for 42 days prior to first dose of study drug, and must agree to refrain from such products while on study * Adequate hematologic, renal and liver function Exclusion Criteria: * Prior treatment with vemurafenib or other BRAF inhibitor within 42 days of Day 1 * History of or current clinically significant cardiac or pulmonary dysfunction, including current uncontrolled Grade \>/= 2 hypertension or unstable angina * Current dyspnea at rest due to complications of advanced malignancy or any requirement for supplemental oxygen * Active central nervous system lesions (participants with radiographically unstable, symptomatic lesions) * Participants with CYP1A2 gene mutation (-3113G-\>A), either in one or two alleles * Allergy or hypersensitivity to vemurafenib or tizanidine formulations * Current severe uncontrolled systemic disease * Inability or unwillingness to swallow pills * History of malabsorption or other condition that would interfere with enteral absorption of study treatment * History of clinically significant liver disease (including cirrhosis), current alcohol abuse, or human immunodeficiency (HIV) infection requiring antiretroviral treatment, acquired immune deficiency syndrome (AIDS)-related illness, or active hepatitis B or C * Pregnant or breastfeeding women