A Safety Study of 212Pb-VMT-alpha-NET in Patients With Neuroendocrine Tumors

This research study is designed to explore if a new radiotherapeutic (radioactive) drug, named 212Pb (212-lead) VMT-α-NET, works against neuroendocrine tumor cells. To begin researching this drug, we need to determine if \[212Pb\] VMT-α-NET is safe and tolerable when used as a cancer treatment. As a safety study, it is unknown if the treatment is safe or effective. The study will also estimate the radiation dose to the kidneys for this treatment. To calculate this radiation dose, imaging is also performed with the sister drug, \[203Pb\] VMT-α-NET using SPECT/CT imaging. Each participant is assigned a radiation dose to the kidneys that cannot be exceeded. The study is testing the safety of the specific radiation dose to the kidneys when using \[212Pb\] VMT-α-NET. Participants are assigned a radiation dose based on how other participants have tolerated the \[212Pb\] VMT-α-NET. The amount of \[212Pb\] VMT-α-NET administered varies person-to-person because of each person's unique tumor uptake of \[203Pb\] VMT-α-NET and how long it lasts in the body. The study involves 2 treatments, about 8 to 10 weeks apart. The drug is given by infusion once per treatment. The participants also receive an infusion of amino acids to help protect the kidneys as well as medications to help protect against nausea (feeling sick to the stomach). Once a participant is administered the \[212Pb\] VMT-α-NET, they must be followed (i.e. come back to the clinic) for at least 6 months for safety assessments. Safety assessments include blood tests to check bone marrow, kidney, and liver function as well as urinary tests to check kidney function. Participants will also have imaging at 6 months post-treatment to measure how their tumors responded to therapy. Participants will have lifelong follow-up for this study.