Marcia Brose, MD, PhD, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, discusses findings from COSMIC-311 (NCT03690388), a Phase III study evaluating the efficacy of cabozantinib in patients with radioiodine-refractory differentiated thyroid cancer. A total of 187 patients who had progressed after prior VEGFR-targeted therapy were randomized 2:1 to receive cabozantinib or placebo. At the planned interim analysis, cabozantinib demonstrated a clinically and statistically significant improvement in progression-free survival over placebo; no unexpected toxicities were observed. COSMIC-311 represents the first study to show an agent’s activity after lenvatinib use, so cabozantinib may represent a new standard of care in patients with previously treated differentiated thyroid cancer. This interview took place at the American Society of Clinical Oncology (ASCO) 2021 Virtual Meeting.