124I-L19SIP

**124I-L19SIP** is a radiolabeled small immunoprotein (SIP) antibody fragment targeting the extra domain B (ED-B) of fibronectin, a marker of tumor angiogenesis. It is composed of the L19 SIP fragment labeled with the positron-emitting isotope iodine-124. The main use is for immuno-PET imaging to visualize and quantify tumor neovasculature and to plan or guide radioimmunotherapy with related agents such as 131I-L19SIP (radretumab). The L19 SIP fragment binds specifically to the ED-B domain of fibronectin, which is highly expressed in the extracellular matrix of newly formed tumor blood vessels and some stromal structures in tumors, but minimally present in normal adult tissues. The mechanism of action is through antibody binding to this extracellular target, allowing for imaging (and in the context of other isotopes, therapeutic) targeting of tumor vasculature. Developer is Philogen, and academic collaborators such as ETH Zurich have also contributed.

Other names

124I-L19SIP124I-L19-SIPiodine-124 L19SIPiodine124 L19SIPiodine 124 L19SIP