A Phase I Trial of the Alpha Particle-emitting Radiopharmaceutical, Af-001, in Patients With Differentiated Thyroid Cancer
\<Part Ia\> To evaluate the safety and tolerability of a single intravenous dose of af-001 in patients with radically unresectable, recurrent, metastatic differentiated thyroid cancer (papillary carcinoma, follicular carcinoma) refractory to or intolerant of standard-of-care therapy, who have received total thyroidectomy, and to determine the MTD (Maximum tolerated dose) \<Part Ib\> To evaluate the efficacy and safety of three intravenous doses of af-001 administered at 8-week intervals to patients with radically unresectable, recurrent, metastatic differentiated thyroid cancer (papillary carcinoma, follicular carcinoma), who have received total thyroidectomy and are RAI naïve, randomized into two arms at the determined MTD or the MTD-1 dose level, and to determine the recommended Phase II dose (RP2D)
⁃ \<Ia part\>
• Patients with differentiated thyroid cancer (papillary carcinoma, follicular carcinoma) after total thyroidectomy.
• Patients with radically unresectable, recurrent, metastatic disease who are judged by the principal investigator or sub-investigator (hereinafter, principal/sub-investigators) to be refractory to or intolerant of standard-of-care therapy.
⁃ \<Ib part\>
• Patients with radically unresectable, recurrent, metastatic disease who are RAI naive
• Patients with measurable lesions. \<Ia/Ib part\>
• Patients with an Eastern Cooperative Oncology Group (ECOG) performance status (PS) of 0 to 2 and stable general condition.
• Patients expected to survive for at least 6 additional months based on clinical symptoms and physical examination findings.