KEYNOTE-717: Randomized Phase 2 Trial of Adding Local Hypofractionated Radiotherapy to Pembrolizumab in Recurrent or Metastatic Head and Neck Cancer

Announcer:
Welcome to DataPulse from ESMO 2025 on ReachMD. This activity, titled “KEYNOTE-717: Randomized Phase 2 Trial of Adding Local Hypofractionated Radiotherapy to Pembrolizumab in Recurrent or Metastatic Head and Neck Cancer” is provided by Prova Education.

Dr. Hecht:
Welcome from the ESMO 2025 conference in Berlin. My name is Dr. Markus Hecht, and I will present you the results of the KEYNOTE-717 trial.

The trial studied if local radiotherapy to a single tumor lesion can increase the systemic response rate to pembrolizumab in metastatic head and neck cancer.

The trial was planned as a randomized phase 2 trial, and patients were randomized to receive either pembrolizumab monotherapy or the combination with radiotherapy up to 36 Gy delivered into 12 fractions. As we had learned from preclinical experiments that timing is essential when these both treatments are combined to induce abscopal effects, there was a strict time schedule in the delivery of radiotherapy and pembrolizumab.

Altogether, 115 patients were enrolled, and the primary endpoint of the trial was the response rate according to iRECIST criteria. In the analysis, we found an overall response rate of 35% in the combination arm compared to 22% in the control arm, which met the predefined level for statistical significance. The trial met its primary endpoint. Secondary analysis of overall survival showed there was no difference in both arms, whereas the trial was not powered for this endpoint. So taken together, radiotherapy increased the response rate to pembrolizumab in metastatic head and neck cancer, whereas this did not transfer into a survival benefit.

The conclusion is, at the moment, this has no impact on the clinical standard treatments; however, it showed that abscopal effects exist in head and neck cancer in combination with immunotherapy, and this direction should be continued for future research projects.

Announcer:
Thank you for listening to this DataPulse from ESMO 2025 on ReachMD. This activity is provided by Prova Education. Thank you for listening.