Optochemical Control of Immune Checkpoint Blockade via Light‐Triggered PD‐L1 Dimerization

The blockade of PD-1/PD-L1, which serves to "release the brake" of tumor immunity, represents a promising approach for treating various malignancies. However, the systemic immune-related side effects significantly undermine its therapeutic efficacy. To address this dilemma, a photoactivatable and biocompatible prodrug cBMS-1 based on the concept of photopharmacology is reported. The prodrug exhibits negligible toxicity but exerts effective PD-1/PD-L1 axis inhibition upon light irradiation, holding promising potential to achieve local activation of immune responses in clinical settings.