90Y-NM600 targeted radionuclide therapy induces immunologic memory in syngeneic models of T-cell Non-Hodgkin's Lymphoma

Finding improved therapeutic strategies against T-cell Non-Hodgkin's Lymphoma (NHL) remains an unmet clinical need. We implemented a theranostic approach employing a tumortargeting alkylphosphocholine (NM600) radiolabeled with Y-86 for positron emission tomography (PET) imaging and Y-90 for targeted radionuclide therapy (TRT) of T-cell NHL. PET imaging and biodistribution performed in mouse models of T-cell NHL showed in vivo selective tumor uptake and retention of Y-86-NM600. An initial toxicity assessment examining complete blood counts, blood chemistry, and histopathology of major organs established Y-90-NM600 safety. Mice bearing T-cell NHL tumors treated with Y-90-NM600 experienced tumor growth inhibition, extended survival, and a high degree of cure with immune memory toward tumor reestablishment. Y-90-NM600 treatment was also effective against disseminated tumors, improving survival and cure rates. Finally, we observed a key role for the adaptive immune system in potentiating a durable anti-tumor response to TRT, especially in the presence of microscopic disease.