68Ga-grazytracer

68Ga-grazytracer is a novel radiotracer developed for positron emission tomography (PET) imaging that targets granzyme B, a crucial effector molecule secreted by activated CD8+ T cells during immune responses. This innovative imaging agent has shown promising results in assessing immunotherapy efficacy in cancer patients. Developed based on non-aldehyde peptidomimetics, it exhibits excellent in vivo metabolic stability and favorable targeting efficiency to granzyme B. Clinical trials have demonstrated its effectiveness in predicting tumor responses to immune checkpoint inhibitors and adoptive T cell transfer therapy and its superior predictive value for short-term prognosis and progression-free survival compared to conventional assessment criteria. It allows for noninvasive visualization of CD8+ T cell effector function.