Inert coupling of IRDye800CW and zirconium-89 to monoclonal antibodies for single- or dual-mode fluorescence and PET imaging

<p>IRDye800CW and zirconium-89 (Zr-89) have very attractive properties for optical imaging and positron emission tomography (PET) imaging, respectively. Here we describe a procedure for dual labeling of mAbs with IRDye800CW and Zr-89 in a current good manufacturing practice (cGMP)-compliant way. IRDye800CW and Zr-89 are coupled inertly, without impairment of immunoreactivity and pharmacokinetics of the mAb. Organ and whole-body distribution of the final product can be assessed by optical and PET imaging, respectively. For this purpose, a minimal amount of the chelate N-succinyldesferrioxamine (N-sucDf) is first conjugated to the mAb. Next, N-sucDf-mAb is conjugated with IRDye800CW, after which the N-sucDf-mAb-IRDye800CW is labeled with Zr-89. After each of these three steps, the product is purified by gel filtration. The sequence of this process avoids unnecessary radiation exposure to personnel and takes about 5 h. The process can be scaled up by the production of large batches of premodified mAbs that can be dispensed and stored until they are labeled with Zr-89.</p>

PET imaging with radiolabeled antibodies and tyrosine kinase inhibitors: immuno-PET and TKI-PET

During the last decade, the discovery of critical tumor targets has boosted the design of targeted therapeutic agents with monoclonal antibodies (mAbs) and tyrosine kinase inhibitors (TKIs) receiving most of the attention. Immuno-positron emission tomography (immuno-PET) and TKI-PET, the in vivo tracking and quantification of mAbs and TKIs biodistribution with PET, are exciting novel options for better understanding of the in vivo behavior and efficacy of these targeted drugs in individual patients and for more efficient drug development. Very recently, current good manufacturing practice compliant procedures for labeling of mAbs with positron emitters have been described, as well as the preparation of some radiolabeled TKIs, while the first proof of principle studies has been performed in patients. In this review, technical developments in immuno-PET and TKI-PET are described, and their clinical potential is discussed. An overview is provided for the most appealing preclinical immuno-PET and TKI-PET studies, as well as the first clinical achievements with these emerging technologies