A Phase 1 Study of [225Ac]-FPI-1434 Injection

\[111In\]-FPI-1547 is a targeted radioimmuno-imaging agent that consists of FPI-1175, an insulin-like growth factor-1 receptor (IGF-1R)-targeting humanized monoclonal antibody, a bifunctional chelate, and Indium-111, a radionuclide. Patients will receive \[111In\]-FPI-1547 Injection of 185 MBq (5 mCi) for imaging.

\[225Ac\]-FPI-1434 is a targeted alpha radioimmuno-therapeutic agent that consists of FPI-1175, an insulin-like growth factor-1 receptor (IGF-1R)-targeting humanized monoclonal antibody, a bifunctional chelate, and Actinium-225, an alpha-emitting radionuclide. Patients will receive multiple doses of \[225Ac\]-FPI-1434 Injection. Dose is per cohort assignment.

FPI-1175 is an insulin-like growth factor-1 receptor (IGF-1R)-targeting humanized monoclonal antibody without a radioisotope. Patients will receive FPI-1175 Infusion at a dose per cohort assignment.

\[225Ac\]-FPI-1434 is a targeted alpha radioimmuno-therapeutic agent that consists of FPI-1175, an insulin-like growth factor-1 receptor (IGF-1R)-targeting humanized monoclonal antibody, a bifunctional chelate, and Actinium-225, an alpha-emitting radionuclide. Patients will receive a single dose of \[225\]-FPI-1434 Injection. Dose is per cohort assignment.