Radioactive drugs to treat NETs were available in Europe for many years and peptide receptor radionuclide therapy (PRRT) was approved there in 2017. The following year, the U.S. FDA approved Lutetium-177 (Lu-177) to treat NETs in the GI tract and pancreas, and iobenguane i-131 (i-131) to treat advanced pheochromocytoma or paraganglioma. These radioactive drugs are delivered intravenously to target specific characteristics of NET cells. This therapy is also known as radioligand therapy.
PRRT is a method of delivering radioactive drugs through the bloodstream. Unlike healthy cells, some NET cells have proteins (called receptors) on their cell surface that can bind to hormones. PRRT targets and kills tumor cells by releasing radioactive compounds, called radiopeptides, that can bind to these receptors and then emit radiation to kill NET cells.
Studies of Lu-177 have shown PRRT can:
Although generally well tolerated, PRRT with Lu-177 may have side effects such as:
These common side effects are often mitigated or avoided by taking amino acids, fluids, and antinausea medication at the time of treatment. Less common and more serious side effects include bone marrow or kidney toxicity. Studies have shown there is a risk of less than 2% of developing blood cancers such as leukemia or myelodysplastic syndrome.
NETRF has funded research to study new nuclear particles to be used in PRRT, as well as combinations of PRRT and existing drugs that may make the treatment more effective.