RCC patients only: Having received chemotherapy prior to study entry within 5 half-lives of the agent (as described in the package insert), or 4 weeks prior to registration (whichever is shorter) with resolution of side effects from therapy to =< grade 1Xx_NEWLINE_xXPatient must have received their last dose of the biologic agent >= 7 days prior to study registration* For biologic agents that have a prolonged half-life, at least three half-lives must have elapsed prior to registrationXx_NEWLINE_xXMonoclonal antibody treatment: at least three half-lives must have elapsed prior to registrationXx_NEWLINE_xXThe participant has received prior treatment with a small molecule kinase inhibitor or a hormonal therapy (including investigational kinase inhibitors or hormones) within 4 weeks or five half-lives of the compound or active metabolites, whichever is longer, before the first dose of study treatment; note: participants with prostate cancer currently receiving luteinizing hormone-releasing hormone (LHRH) or gonadotropin-releasing hormone (GnRH) agonists may be maintained on these agentsXx_NEWLINE_xXThe subject has received prior treatment with a small molecule kinase inhibitor or a hormonal therapy (including investigational kinase inhibitors or hormones) within 14 days or five half-lives of the compound or active metabolites, whichever is longer, before the first dose of study treatmentXx_NEWLINE_xXUse of other investigational drugs within 28 days (or five half-lives, whichever is shorter; with a minimum of 14 days from the last dose) preceding the first dose of trametinib and during the studyXx_NEWLINE_xXUse of other investigational drugs within 28 days (or five half-lives, whichever is shorter; with a minimum of 14 days from the last dose) preceding the first dose of study treatment and during the studyXx_NEWLINE_xXUse of other investigational drugs within 28 days (or five half-lives, whichever is shorter; with a minimum of 14 days from the last dose) preceding the first dose of study treatment and during the studyXx_NEWLINE_xXPatients who are receiving any other investigational agents have received any other investigational drugs within 28 days (or five half-lives, whichever is shorter; with a minimum of 14 days from the last dose) preceding the first dose of study treatment and during the studyXx_NEWLINE_xXUse of other investigational drugs within 28 days (or five half-lives, whichever is shorter; with a minimum of 14 days from the last dose) preceding the first dose of trametinib and during the study; patients previously treated with v-raf murine sarcoma (RAF) and/or mitogen-activated protein kinase (MEK) inhibitors are excluded from the study; multikinase antiangiogenic tyrosine kinase inhibitors such as regorafenib, sorafenib, sunitinib, etc. whose primary mechanism of action is not RAF inhibition, are allowed; if there are any questions, please contact study's principal investigatorXx_NEWLINE_xXUse of other investigational drugs within 28 days (or five half-lives, whichever is shorter; with a minimum of 14 days from the last dose) preceding the first dose of study drug(s) and during the studyXx_NEWLINE_xXPatients who are receiving any other investigational agents; patients who have taken an investigational drug within 28 days or 5 half-lives (minimum 14 days), whichever is shorter, prior to randomizationXx_NEWLINE_xXUse of other investigational drugs within 28 days (or five half-lives, whichever is shorter; with a minimum of 14 days from the last dose) preceding the first dose of trametinib or standard of care agentXx_NEWLINE_xXExposure to an investigational product within 30 days or five half-lives (whichever is the longer) prior to randomizationXx_NEWLINE_xXUse of other investigational drugs within 28 days (or five half-lives, whichever is shorter; with a minimum of 14 days from the last dose) preceding the first dose of trametinib and during the studyXx_NEWLINE_xXUse of other investigational drugs within 28 days (or five half-lives, whichever is shorter; with a minimum of 14 days from the last dose) preceding the first dose of study treatment and during the study; patients that have used other BRAF or mitogen-activated protein kinase kinase (MEK) inhibitor are excludedXx_NEWLINE_xXThe subject has received prior treatment with a small molecule kinase inhibitor within 14 days or five half-lives of the compound or active metabolites, whichever is longer, before the first dose of study treatmentXx_NEWLINE_xXThe subject has received prior treatment with hormonal therapy within 14 days or five half-lives of the compound or active metabolites, whichever is longer, before the first dose of study treatment; subjects receiving gonadotropin-releasing hormone (GnRH) agonists and antagonists are allowed to participateXx_NEWLINE_xXPatients who are receiving any other investigational agents within 4 weeks or 5 half-lives (whichever is later) prior to the first dose of the study regimenXx_NEWLINE_xXAt least 14 days from the last therapy dose or 5 half-lives (whichever is shorter), and resolution of toxicity related to the last therapy, excluding grade 2 or less peripheral neuropathy and alopecia; for radiation therapy, a minimum of 2 weeks and resolution of all acute toxicity will be requiredXx_NEWLINE_xXRECURRENT/ PROGRESSIVE DIPG (STRATUM 1): Monoclonal antibody treatment and agents with known prolonged half-lives: at least three half-lives must have elapsed prior to enrollment* Note: A list of the half-lives of commonly used monoclonal antibodies is available on the Pediatric Brain Tumor Consortium (PBTC) webpage under Generic Forms and TemplatesXx_NEWLINE_xXReceipt of an investigational study drug for any indication within 30 days or 5 half-lives (whichever is longer) prior to day 1 of protocol therapyXx_NEWLINE_xXMonoclonal antibody treatment and agents with known prolonged half-lives: at least three half-lives must have elapsed prior to enrollmentXx_NEWLINE_xXUse of other investigational drugs within 28 days (or five half-lives, whichever is shorter; with a minimum of 14 days from the last dose) preceding the first dose of talimogene laherparepvec (T-VEC) and during the studyXx_NEWLINE_xXFrom the projected start of scheduled study treatment, the following time periods must have elapsed: 5 half-lives from investigational agents, 4 weeks from cytotoxic therapy (except 23 days for temozolomide and 6 weeks from nitrosoureas), 6 weeks from antibodies, or 4 weeks (or 5 half-lives, whichever is shorter) from other systemic anti-tumor therapies; treatment on study may start one day after discontinuation of the optune deviceXx_NEWLINE_xXUse of other investigational, chemotherapeutic or targeted drugs within 28 days (or five half-lives, whichever is shorter; with a minimum of 14 days from the last dose) preceding the first dose of talimogene laherparepvec and during the study are ineligibleXx_NEWLINE_xXUse of other investigational drugs within 28 days (or five half-lives, whichever is shorter; with a minimum of 14 days from the last dose) preceding the first dose of trametinib and during the studyXx_NEWLINE_xX