Immune Checkpoint Inhibitor and MR-guided SBRT for Limited Progressive Metastatic Carcinoma.

This is an open label single arm phase 2 clinical trial in patients with metastatic solid malignancy of any histology who have previously experienced limited progression in at least 1 and up to 5 lesions while on immune checkpoint inhibitors monotherapy.

All potential subjects are required to undergo screening evaluation to determine eligibility within 28 days of study enrollment. Eligible subjects will continue the same immune checkpoint inhibitors on which they experienced limited progression and will also receive radiation therapy. radiation therapy for all subjects will consist of treating one tumor of the treating physician's preference, and after a 1-week interval during which immune checkpoint inhibitor is continued alone, radiation therapy will be given to a second and separate tumor. No additional radiation therapy will be delivered. immune checkpoint inhibitors will be continued until disease progression or unacceptable toxicity. Diagnostic imaging studies will be performed to determine treatment response at baseline/screening, 8 weeks after initiation of radiation therapy to the first lesion and every 8 weeks thereafter. Peripheral blood mononuclear cell composition will be evaluated at various time points within 14 days of starting radiation therapy, on Day 8 (1 week after starting radiation therapy to the first lesion), Day 23 (1 week after starting radiation therapy to the second lesion), and 8 weeks after treatment initiation. A total of 52 subjects will be enrolled on this trial. The expected rate of accrual is 2 patients per month at a single institution over 26 months.