Neoadjuvant stereotactic body radiation therapy with durvalumab and oleclumab in ER⁺HER2⁻ breast cancer: a randomized phase 2 trial

The Neo-CheckRay trial was a randomized phase 2 study focusing on breast cancer treatment. Patients with early-stage ER⁺HER2⁻ breast cancer received neoadjuvant immune-modulating stereotactic body radiation therapy. This therapy was administered either with or without durvalumab, and also with or without the anti-CD73 antibody oleclumab. The aim was to evaluate the efficacy of the combined treatment. Results showed encouraging clinical responses, particularly when durvalumab was added to the treatment regimen. These positive responses were observed even in patients with PD-L1-negative tumors. The study was published in Nature Medicine on June 25, 2026.