4-1BB Aptamer-Based Immunomodulation Enhances the Therapeutic Index of Radiation Therapy in Murine Tumor Models

Radiation therapy synergizes with 4-1BB mAb, and this effect is dependent on RT dose and fractionation. Tumor control by 4-1BB aptamer is equivalent to 4-1BB mAb when combined with optimal RT dose, without eliciting off-target liver and spleen CD8+ expansion. 4-1BB aptamer-based costimulation affords a comparable and less toxic strategy to augment RT-mediated tumor control.