90Y-IsoPet is a hydrogel liquid made of water-based biodegradable polymer that delivers 90Y-microspheres directly into tumor tissues. At body temperature, the product polymerizes into a lattice that traps the 90Y microspheres in place. It was initially developed under the name RadioGel.
In 2019, the drug became available in the US and EU for veterinary nuclear medicine application under the brand name IsoPet®. The injectable IsoPet® (or RadioGel™) is administered directly into the tumor and may also be administered transdermally or intraoperatively when treating solid tumors that cannot be removed safely by surgical excision, such as inoperable liver cancer, brain tumors, head and neck tumors, kidney tumors, and pancreatic cancer.
The initial indication was prostate cancer. In February 2014, the FDA determined that the product is classified by statute as a Class III medical device. Additional data have been requested by FDA, but over time, it appeared that launching a veterinary formulation would at least generate cash, while RadioGel can be further developed in parallel for human use. Despite the same formulation, the FDA advised using different product names in order to avoid confusion and cross-use. The veterinary formulation is sold under the brand name 90Y-IsoPet® while the human formulation, when available, will be sold under the brand name 90Y-RadioGel™. (Presently this drug is not available for human use)