Evaluation of maSSS/maSES-PEG2-RM26 for their potential therapeutic use after labeling with Re-188. Could their [Tc]Tc-labeled counterparts be used to estimate dosimetry?

Background: Gastrin releasing peptide receptor (GRPR)-directed radiopharmaceuticals for targeted radionuclide therapy may be a very promising addition in prostate and breast cancer patient management. Aiming to provide a GRPR-targeting theranostic pair, we have utilized the Tc-99m/Re-188 radiometal pair, in combination with two bombesin based antagonists, maSSS-PEG2-RM26 and maSES-PEG2-RM26. The two main aims of the current study were (i) to elucidate the influence of the radiometal-exchange on the biodistribution profile of the two peptides and (ii) to evaluate the feasibility of using the [Tc]Tc labeled counterparts for the dosimetry estimation for the [Re]Re-labeled conjugates.

Structural Basis of Activity of HER2-Targeting Construct Composed of DARPin G3 and Albumin-Binding Domains.

Non-immunoglobulin-based scaffold proteins (SPs) represent one of the key therapeutic target-specific and high-affinity binders in modern medicine. Among their cellular targets are signaling receptors, in particular, receptor tyrosine kinases, whose dysfunction leads to the development of cancer and other serious diseases. Successful applications of SPs have been reported for HER receptor type 2 (HER2), a member of the human epidermal growth factor receptor family that regulates cell growth and differentiation.

Phase I Clinical Evaluation of Designed Ankyrin Repeat Protein [Tc]Tc(CO)-(HE)-Ec1 for Visualization of EpCAM-Expressing Lung Cancer.

A high level of EpCAM overexpression in lung cancer makes this protein a promising target for targeted therapy. Radionuclide visualization of EpCAM expression would facilitate the selection of patients potentially benefiting from such treatment. Single-photon computed tomography (SPECT) using Tc-labeled engineered scaffold protein DARPin Ec1 has shown its effectiveness in imaging tumors with overexpression of EpCAM in preclinical studies, providing high contrast just a few hours after injection.

Evaluation of HER2/neu Expression in Metastatic Axillary Lymph Node Tissue of Breast Cancer Patients Using [99mTc]Tc-(HE)3-G3.

Anatomic visualization and molecular typing of metastatic regional lymph nodes in breast cancer patients are a serious clinical challenge in modern oncology. According to the results of previous studies, [99mTc]Tc-(HE)3-G3 has proven to be a promising diagnostic agent in differentiating the HER2/neu receptor status in primary breast tumors ( < 0.05, Mann-Whitney test).