Inclusion Criteria:  Provide written informed consent prior to initiation of any study-specific procedures. Metastatic or advanced stage solid tumor Known BRAF Class I, Class II, or Class III alteration or melanoma with an NRAS mutation as confirmed by previous genomic analysis of tumor tissue or ctDNA. Measurable or evaluable disease by RECIST v1.1. ECOG performance status 0, 1, or 2. Adequate organ function, as measured by laboratory values (criteria listed in protocol). Able to swallow, retain, and absorb oral medications.  Exclusion Criteria:  Known clinically-active or clinically-progressive brain metastases from non-brain tumors. In Part B Dose Expansion, previous treatment with any approved or in-development small molecule BRAF-, MEK-, or MAPK-directed inhibitor therapy. GI tract disease causing an inability to take oral medication, malabsorption syndrome, requirement for intravenous alimentation, or uncontrolled inflammatory GI disease. Active, uncontrolled bacterial, fungal, or viral infection. Participant with a positive test result for SARS-CoV2 infection, is known to have asymptomatic infection or is suspected of having SARS-CoV2, is excluded Women who are lactating or breastfeeding, or pregnant. In Part B Dose Expansion, patients with BRAF Class I mutations are excluded.  Complete inclusion and exclusion criteria are listed in the clinical study protocol.