Inclusion Criteria:

          -  Patient must have locally advanced unresectable stage IIIC or stage IV melanoma

          -  Patient must have BRAF V600E or BRAF V600K tumor genotype based on a Clinical
             Laboratory Improvement Act (CLIA) approved assay

          -  Patient must have measurable disease by Response Evaluation Criteria in Solid Tumors
             (RECIST) 1.1. Baseline measurements of sites of disease must be obtained within 3
             weeks prior to study randomization

          -  Patient must have been treated with prior immune checkpoint inhibitor therapy (anti
             PD-1 antibody, anti-CTLA-4 antibody or a combination regimen including either or both
             agents) either in the adjuvant or metastatic setting. Patient may have received
             investigational agents in combination with standard therapy, as long as it was
             adhering to the timeframes

               -  Patient must have discontinued active immunotherapy (IL-2, interferon,
                  anti-CTLA-4 antibody, anti-PD-1 antibody etc.) or chemotherapy at least 4 weeks
                  prior to randomization

               -  Patient must have discontinued any oral targeted therapy at least 2 weeks prior
                  to randomization

               -  Patients must not receive any other investigational anticancer therapy during the
                  period on study or the 4 weeks prior to randomization

          -  Patient may have been treated with prior adjuvant therapy including combined BRAF and
             MEK inhibitor therapy. Patients will be eligible if they tolerated this therapy and
             did not discontinue the therapy due to toxicity AND >= 6 months have elapsed since the
             end of adjuvant BRAF and MEK inhibition. If patients received BRAF and MEK inhibitor
             therapy in the metastatic setting, they are not eligible

          -  Patient may have been treated with prior chemotherapy or radiation therapy

          -  Patient must have an Eastern Cooperative Oncology Group (ECOG) performance status of 0
             or 1

          -  Patients with a prior or concurrent malignancy whose natural history or treatment does
             not have the potential to interfere with the safety or efficacy assessment of the
             investigational regimen are eligible for this trial

          -  Women of childbearing potential and sexually active males must not expect to conceive
             or father children by using accepted and effective method(s) of contraception or
             abstaining from sexual intercourse for the duration of their participation in the
             study and for 4 months after the last dose of protocol treatment

          -  Patient must have recovered from clinically significant reversible toxicities from
             previous treatment prior to randomization. Abnormal laboratory values may be grade 1,
             as long as they meet the eligibility criteria

          -  Patient must be able to swallow and retain oral medication and must not have any
             clinically significant gastrointestinal abnormalities that may alter absorption such
             as malabsorption syndrome or major resection of the stomach or bowels

          -  Patient must have the ability to understand and the willingness to sign a written
             informed consent document. Patients with impaired decision-making capacity (IDMC) who
             have a legally authorized representative (LAR) or caregiver and/or family member
             available will also be considered eligible

          -  Absolute neutrophil count >= 1,500/mcL (obtained =< 14 days prior to protocol
             randomization)

          -  Platelets >= 100,000/mcL (obtained =< 14 days prior to protocol randomization)

          -  Total bilirubin =< institutional upper limit of normal (ULN) (obtained =< 14 days
             prior to protocol randomization)

          -  Aspartate aminotransferase (AST) (serum glutamic-oxaloacetic transaminase
             [SGOT])/alanine aminotransferase (ALT) (serum glutamate pyruvate transaminase [SGPT])
             =< 3.0 x institutional ULN (obtained =< 14 days prior to protocol randomization)

          -  Creatinine =< 1.5 x institutional ULN (obtained =< 14 days prior to protocol
             randomization)

          -  Human immunodeficiency virus (HIV)-infected patients on effective anti-retroviral
             therapy with undetectable viral load within 6 months are eligible for this trial

          -  For patients with evidence of chronic hepatitis B virus (HBV) infection, the HBV viral
             load must be undetectable on suppressive therapy, if indicated

          -  Patients with a history of hepatitis C virus (HCV) infection must have been treated
             and cured. For patients with HCV infection who are currently on treatment, they are
             eligible if they have an undetectable HCV viral load

          -  Patient with asymptomatic new or progressive brain metastases (active brain
             metastases) are eligible if the treating physician determines that CNS specific
             treatment is not required

               -  NOTE: Patient with treated brain metastases are eligible. No brain imaging is
                  required, however, 1 week must elapse after gamma knife therapy. Patient treated
                  with whole brain radiation that have been stable for 2 months are eligible.
                  Patient are excluded if they have leptomeningeal disease or metastases causing
                  spinal cord compression that are symptomatic or untreated or not stable
                  (documented by imaging) for at least 3 months or requiring corticosteroids.
                  Patients on a stable dose of corticosteroids for at least 1 month or who have
                  been off of corticosteroids for at least 1 week are eligible

        Exclusion Criteria:

          -  Patients who are known to be experiencing an objective partial response to
             immunotherapy at the time of study enrollment are not eligible

          -  Women must not be pregnant or breast-feeding due to the potential harm to an unborn
             fetus and possible risk for adverse events in nursing infants with the treatment
             regimens being used. All females of childbearing potential must have a blood test or
             urine study within 14 days prior to randomization to rule out pregnancy. A female of
             childbearing potential is defined as any woman, regardless of sexual orientation or
             whether they have undergone tubal ligation, who meets the following criteria: 1) has
             achieved menarche at some point, 2) has not undergone a hysterectomy or bilateral
             oophorectomy; or 3) has not been naturally postmenopausal (amenorrhea following cancer
             therapy does not rule out childbearing potential) for at least 24 consecutive months
             (i.e., has had menses at any time in the preceding 24 consecutive months)

          -  Patient must not have a history of interstitial lung disease (ILD) or chronic
             pneumonitis

               -  NOTE: If there is radiographic evidence of ILD that is clinically insignificant
                  and asymptomatic, the patient would be eligible

          -  Patient must not have porphyria or psoriasis due to risk of disease exacerbation
             unless the disease is well controlled and they are under the care of a specialist for
             the disorder who agrees to monitor the patient for exacerbations

          -  Patient must not have a previously documented retinal vein occlusion

          -  Patient must not have a history or evidence of increased cardiovascular risk
             including:

               -  Left ventricular ejection fraction (LVEF) < institutional lower limit of normal
                  measured within 14 days prior to randomization

               -  A QT interval corrected for heart rate using the Bazett's formula >= 480 msec

               -  Current clinically significant uncontrolled arrhythmias. Exception: Patients with
                  controlled atrial fibrillation for > 30 days prior to randomization are eligible

               -  Acute coronary syndromes (including myocardial infarction and unstable angina),
                  coronary angioplasty, or stenting within 6 months prior to randomization

               -  Abnormal cardiac valve morphology (>= grade 2) documented by echocardiogram
                  unless a cardiologist concludes the valve abnormality is not clinically
                  significant. Patients with grade 1 abnormalities (i.e., mild
                  regurgitation/stenosis) are eligible

               -  Patients with known history or current symptoms of cardiac disease, or history of
                  treatment with cardiotoxic agents, should have a clinical risk assessment of
                  cardiac function using the New York Heart Association Functional Classification.
                  To be eligible for this trial, patients should be class 2B or better

          -  Patient with known serious concurrent infection or medical illness, including
             psychiatric disorders, which would jeopardize the ability of the patient to receive
             the treatment outlined in this protocol with reasonable safety are not eligible

          -  Patient must not be receiving concurrent therapy for their tumor (i.e.
             chemotherapeutics or investigational agents). Radiotherapy delivered to palliate pain
             is allowed as long as it is not targeting a lesion that meets RECIST criteria for
             progression. Radiation therapy to the surgical bed with gamma knife radiotherapy while
             on treatment during the first cycle is allowed for small volume surgically resected
             brain metastases. Gamma knife radiotherapy for known active, asymptomatic small volume
             central nervous system (CNS) lesions may be performed during the first cycle while on
             study. Radiotherapy for new CNS lesions identified beyond the first cycle is not
             allowed on study

          -  Patient must not have a known immediate or delayed hypersensitivity reaction or
             idiosyncrasy to drugs chemically related to study drug, or excipients or to dimethyl
             sulfoxide (DMSO)

          -  Patient must not have received cytochrome P450 enzyme -inducing anticonvulsant drugs
             (extended-interval aminoglycoside dosing [EIADs]) (i.e. phenytoin, carbamazepine,
             phenobarbital, primidone or oxcarbazepine) within 4 weeks prior to randomization

          -  Patient must not have a current use of a prohibited medication