Researchers at the First Affiliated Hospital of Soochow University in China reported in the Journal of Nuclear Medicine on October 8, 2026 a gallium-68 tracer built on a dimeric (two-unit) cyclic peptide, [68Ga]Ga-TDN1, that binds nectin-4, a tumor protein also targeted by the antibody-drug conjugate enfortumab vedotin (Padcev). After animal tests showed specific tumor uptake, a first-in-human pilot in six breast cancer patients found it performed comparably to standard FDG PET for primary tumors and lymph nodes and detected bone and liver metastases better. The tracer was well tolerated; the human study is very small.
Researchers at Fujian Medical University reported in Bioconjugate Chemistry on October 8, 2026 that they used the PepMimic AI platform to design TR23, a peptide designed by mimicking a protein binding interface, and labeled it with gallium-68 for PET imaging. The tracer bound TROP-2, a protein common in many solid tumors and the target of the antibody-drug conjugate Trodelvy, with nanomolar strength, and gave clear, specific tumor signals in pancreatic, prostate, and thyroid cancer models in mice, with signal strength tracking TROP-2 levels in tissue. The work is preclinical.
A review from the Indian Institute of Technology Ropar, published October 4, 2026 in the Journal of Peptide Science, surveys linear and cyclic peptides that bind glypican-3, a cell-surface protein that is common in hepatocellular carcinoma but largely absent from normal adult liver. The peptides, found mainly through phage display and structure-guided design, have enabled PET, SPECT, and fluorescence imaging of liver tumors in preclinical models, and albumin-binding changes and cyclization have improved tumor-to-liver contrast and stability. The authors argue that small peptides penetrate tumors faster and clear more quickly than the antibodies used against the same target; the imaging work they review is preclinical.