Study of Efficacy and Safety of Dabrafenib in Combination With Trametinib in Previously Treated Patients With Metastatic, Radio-active Iodine Refractory BRAF V600E Mutation Positive Differentiated Thyroid Cancer

The purpose of this study is to assess the efficacy and safety of dabrafenib in combination with trametinib for treating adult patients with locally advanced or metastatic Differentiated Thyroid Cancer (DTC) harboring the BRAFV600E mutation, who are refractory to radioactive iodine (RAI) therapy and have experienced disease progression following one or two prior VEGFR-targeted treatments.

Key Inclusion Criteria: * Signed informed consent * Male or female ≥ 18 years of age at time of informed consent * Histologically or cytologically confirmed diagnosis of advanced/metastatic differentiated thyroid carcinoma * Radioactive-iodine refractory disease * BRAF V600E mutation-positive tumor sample as per central laboratory result * Has progressed on at least 1 but not more than 2 prior VEGFR targeted therapies * Eastern Cooperative Oncology Group (ECOG) performance status ≤ 2 * At least one measurable lesion as defined by RECIST v1.1. Key Exclusion Criteria: * Anaplastic or medullary carcinoma of the thyroid * Previous treatment with a BRAF inhibitor and/or a MEK inhibitor * Concomitant RET Fusion-Positive Thyroid Cancer * Treatment with any type of small molecule kinase inhibitor (including investigational kinase inhibitor) within 2 weeks before randomization * Treatment with any type of anticancer antibody (including investigational antibody) or systemic chemotherapy within 4 weeks before randomization * Treatment with radiation therapy for bone metastasis within 2 weeks or any other radiation therapy within 4 weeks before randomization * A history or current evidence/risk of retinal vein occlusion (RVO) or central serous retinopathy Other inclusion/exclusion criteria may apply.