A bifunctional antibody targeting PD-1 and TGF-β signaling has antitumor activity in combination with radiotherapy and attenuates radiation-induced lung injury.

Radio-immunotherapy has antitumor activity but also causes toxicity, which limits its clinical application. JS-201 is a dual antibody targeting PD-1 and TGF-β signaling. We investigated the antitumour effect of JS-201 combined with radiotherapy and the effect on radiation-induced lung injury (RILI). Different tumor models were established to detect the antitumor effects of the combination of JS-201 and RT, and RILI models were established to observe the effects of JS-201. Transcriptome sequencing showed that JS-201 optimized the TME by inhibiting extracellular matrix formation and angiogenesis. Combining JS-201 with radiotherapy further increased the inflammatory response and immune infiltration and showed great abscopal effects in LLC-luc models. Single-cell sequencing demonstrated that JS-201 reduced fibroblast proliferation by inhibiting the TGF-β/Smad pathway and the release of neutrophil extracellular traps mediated by ROS, thereby relieving radiation-induced pulmonary fibrosis. In conclusion, the JS-201 and radiotherapy combination enhances antitumor effects while mitigating acute and chronic RILI, and it may have potential for translational investigation as a cancer treatment strategy.