This study seeks to determine the appropriate dose level and effectiveness of combination targeted therapy (mirdametinib + BGB-3245) in people with advanced, metastatic or inoperable solid cancer who have had prior treatmentA Phase 1/2a Open-Label, Dose Escalation and Expansion Study to Investigate the Safety, Pharmacokinetics, Pharmacodynamics and Efficacy of Mirdametinib in Combination With BGB-3245 in Patients With Advanced Solid Tumors

Exclusion

• Central Nervous System metastases, leptomeningeal carcinomatosis or untreated spinal cord compression
• History of glaucoma
• Active parathyroid disorder or history of malignancy associated hypercalcemia
• Clinically significant cardiac disease within the past 6 months of signing ICF
• History of toxicity from another RAF, MEK, ERK inhibitor requiring discontinuation of treatment from these agents
• Severe or uncontrolled systemic disease
• Inability to swallow oral medications
• Clinically significant active infection (HIV, Hepatitis B or Hepatitis C)
• History of or ongoing Immune Thrombocytopenia (ITP), Von Willebrand disease and/or other past or present bleeding disorders
• Underlying medical conditions in investigator's opinion to be unfavorable to be a part of the study
• Major surgical procedure or significant traumatic injury within 4 weeks prior to first dose or anticipates need for major surgery while on study
• Systemic anti-cancer therapy within 2 weeks or 5 half-lives before first dose
• Concomitant systemic or glucocorticoid therapy within 2 weeks before first dose
• Concomitant medicines that are strong CYP3A4 inhibitors or inducers within 2 weeks or 5 half-lives before first dose
• Live vaccine within 4 weeks before first dose