technetium Tc 99m-HYNIC-interleukin-2

**Technetium Tc 99m-HYNIC-interleukin-2** is an investigational technetium-99m radiolabeled interleukin-2 SPECT imaging probe. Interleukin-2 is conjugated through the HYNIC chelator and labeled with technetium-99m, enabling imaging of activated lymphocyte infiltrates that express high-affinity interleukin-2 receptors, particularly CD25-positive activated T cells. It is a diagnostic radiopharmaceutical rather than a therapeutic cytokine product. In a Mayo Clinic early-phase melanoma study, it was evaluated with SPECT/CT to help distinguish immune-cell inflammation associated with checkpoint blockade from true tumor progression. Published studies have also evaluated the tracer for imaging activated T-cell inflammation in lung-transplant rejection and inflamed atherosclerotic plaques. ([clinicaltrials.gov](https://clinicaltrials.gov/study/NCT01789827))

Brand names

none

Other names

99mTc-HYNIC-IL-2[99mTc]Tc-HYNIC-IL-2technetium Tc 99 hydrazinonicotinamide-tricine-linked interleukin-2