117mSn-DTPA was studied in the years 1990s by Brookhaven National Laboratory as a bone pain palliation agent and for the treatment of bone cancers. Its development up to clinical Phase II was stopped due to lack of funds and difficult access to 117mSn. About 120 patients went through a clinical trial before the development was stopped.

However, all these studies pushed the development of other 117mSn-labeled drugs in different indications. In-between, the production issues to obtain industrial amounts of high quality 117mSn were solved. In the course of the year 2019, the development of this drug was reactivated. This drug is also developed in Canine Bone Metastasis therapy.

The development of this drug was based on the hypothesis that marrow toxicity, side effects of analogue pain palliation agents based on beta-emitters such as 32P, 89Sr, 186Re or 153Sm) can be reduced while maintaining therapeutic efficacy using radionuclides that emit short-range beta particles or conversion electrons such as 117mSn.

Target/Mechanism: Bones

Leading Emitter: C.E. (Conversion electron)