Adaptive BRAF-MEK Inhibitor Therapy for Advanced BRAF Mutant Melanoma

Inclusion Criteria: * Patients must be 18 years of age or above * Subjects must have cytologically or histologically-confirmed unresectable melanoma that harbors a BRAF V600E mutation determined by pyrosequencing assay or equivalent genotyping assay in a Clinical Laboratory Improvement Act (CLIA) certified laboratory, meeting one of the following American Joint Committee on Cancer (AJCC) (8th edition) staging criteria: * AJCC stage IV * AJCC stage IIIC or IIID with unresectable nodal/locoregional involvement * Subjects must have baseline plasma ctDNA \>= 0.5 copy/ul at time of study enrollment * Hemoglobin \>= 8.0 g/dL * Absolute neutrophil count \>= 1,500/mcL * Platelets \>= 75,000/mcL * Total bilirubin =\< 2 institutional upper limit of normal (ULN), unless suspected Gilbert's syndrome * Aspartate aminotransferase (AST) and alanine aminotransferase (ALT) =\< 2.5 x institutional ULN (in participants with liver metastases =\< 5 x ULN) * Creatinine =\< 2.0 institutional ULN * Subjects must have an Eastern Cooperative Oncology Group (ECOG) performance status of =\< 2 * Negative serum pregnancy test within 7 days prior to commencement of dosing in premenopausal women. Women of non-childbearing potential may be included without serum pregnancy test if they are either surgically sterile or have been postmenopausal for \>= 1 year * Fertile men and women must use an effective method of contraception during treatment and for at least 6 months after completion of treatment as directe…