Technetium (99Mtc) Nofetumomab (IL3RA/CD123)

Background:

Technetium Tc-99m nofetumomab merpentan (Tc-99m nm) consists of a Fab fragment of an IgG2b of the pancarcinoma murine antibody NR-LU-10.1 The NR-LU-10 antibody is directed against a 40 kDa glycoprotein antigen expressed in a variety of cancers and some normal tissues.Label Tc-99m nm was developed by Boehringer Ingelheim Pharma KG and FDA approved on September 14, 1992. It was after discontinued on August 13, 2013, but in the 2018 FDA submission list, it can be found as a substance type II (Drug substance) with an active status.The mechanism of action in Tc-99m nm is ruled by the presence of nofetumomab, which can recognize the pancarcinoma antigen EpCAM and/or CD20/MS4A1,2 and merpentan,that acts as a linker for the binding of technetium.