QUILT-3.091 NANT Chordoma Vaccine vs Radiation in Subjects With Unresectable Chordoma.

The NANT Chordoma Vaccine regimen will be administered in 2 phases, an induction and a maintenance phase.

Subjects will continue induction treatment for up to 1 year. Those who have a confirmed complete response (CR) in the induction phase will enter the maintenance phase of the study. Subjects who experience ongoing stable disease (SD) or an ongoing partial response (PR) at 1 year may enter the maintenance phase at the Investigator's and Sponsor's discretion. Subjects may remain in the maintenance phase of the study for up to 1 year.

In the randomized component of the phase 2 portion of the study, the control arm will be treated with radiation according to established SoC protocols as determined by the Investigator.

In the phase 2 single-arm component of the study, subjects will be enrolled in the first stage of Simon's two-stage optimal design. If the study proceeds to the second stage of Simon's two-stage optimal design, additional subjects will be enrolled in the second stage.