A phase 1 trial shows promise with a novel approach of sub-ablative radiation to gross tumor with a single infusion of durvalumab 3-6 weeks prior to resection of locally-advanced HPV- oropharyngeal squamous cell carcinoma. After lower radiation doses proved safe, 24 patients received 6-8 Gy x 3 every other day. Of these, 12/16 (75%) evaluable patients achieved a major or complete pathologic response at time of surgery. Of 9 patients receiving 8 Gy x 3, 8 (89%) achieved a major or complete pathologic response. Science-y investigations of serum of tumor specimens suggests this was due to successful recruitment of the immune system as there was a demonstrable increase in antigen-presentation and effector-T cells with a decrease in immunosuppressive cells.
- Darragh, Nat Cancer 2022