¹⁸⁶Re-Rhenium Etidronate was developed for use in relieving the pain associated with metastatic bone cancer. The formulation had been approved and launched in Switzerland and Greece, but the NDA submitted to the US FDA was never approved and the project was discontinued in the US. Eventually, the product was also withdrawn from the EU countries. In developing countries generic copies found some interest (mainly because established competitors with IP were too expensive) and the drug is still available outside of the EU and US.

¹⁸⁶Re-HEDP is indicated for bone pain palliation in cancer metastases (prostate, breast).

Target/Mechanism: Bones

Carrier/Ligand: n/a

Radiation Type: beta electrons (β^–)