Lenvatinib 24 mg/Day Versus 10 mg/Day to Treat Symptomatic or Progressive Radioactive Iodine Resistant (RAIR) Differentiated Thyroid Cancer (DTC)

This study compares two doses of lenvatinib — a standard 10 mg/day dose versus a higher 24 mg/day dose — in people with differentiated thyroid cancer (papillary, follicular, or Hurthle cell) that no longer responds to radioactive iodine (RAI) treatment and is progressing or causing symptoms. **You may be eligible if...** - You have a confirmed diagnosis of differentiated thyroid cancer that is radioactive iodine-resistant - Your cancer is incurable by surgery and is either progressing, symptomatic, or not responding to RAI - You have measurable disease on imaging - You have not previously received lenvatinib or similar drugs (VEGFR inhibitors) **You may NOT be eligible if...** - You have previously been treated with lenvatinib or similar VEGFR-targeting drugs - You have uncontrolled high blood pressure or significant heart disease - You are pregnant or breastfeeding - You have poorly differentiated or anaplastic thyroid cancer Talk to your doctor to see if this trial is right for you.