Nature Medicine, Published online: 25 June 2026; doi:10.1038/s41591-026-04453-z
In the randomized phase 2 Neo-CheckRay trial, patients with early-stage ER+HER2− breast cancer received neoadjuvant immune-modulating stereotactic body radiation therapy with or without durvalumab, and with or without the anti-CD73 antibody oleclumab, leading to encouraging clinical responses when durvalumab was added including in patients with PD-L1-negative tumors.