Stereotactic Radiotherapy Versus Palliative Conventional Radiotherapy for Oligoprogressive Metastatic Cancers

STOP-2 is a phase III multi-institutional double-blind randomized trial. 194 participants will be enrolled in this trial. Participants will be randomized in a 1:1 ratio between the Control Arm vs. the Experimental Arm. Participants, enrolling oncologists, and the statistician will be blinded to trial arm assignment. In the control arm, radiotherapy will consist of 8 Gy in 1 fraction to all sites of oligoprogression, and the experimental arm will consist of SABR treatment to all sites of oligoprogression. Primary Objectives * To assess the impact of SABR, compared to palliative conventional radiotherapy, on Progression-free survival on next line systemic therapy (PFS-NEST), oncologic outcomes, and Quality of Life (QOL) in participants with 1-5 oligoprogressing lesions. * To assess the feasibility of the clinical trial in terms of accrual and success of double-blinding. Secondary Objectives * To evaluate and compare the impact of SABR and palliative radiation therapy on the overall survival (OS), progression free survival (PFS), polymetastatic progression-free survival (PPFS); * To assess and compare the proportion of participants receiving additional radiation therapy and other metastasis-directed interventions during follow-up between both arms; * To compare the impact of SABR and palliative radiation therapy on the time to initiation of the next line of systemic therapy; * To identify and compare the anatomic sites of disease progression between the experimental (SABR) and control (palliative radiation) arms; * To compare the treatment related toxicity among participants in each arm; * To evaluate and compare the quality of life among participants in each arm; * To assess the cost-effectiveness of the experimental arm compared to the control arm.

NCT Number	NCT06918951
Lead Sponsor	British Columbia Cancer Agency
Conditions	Oligoprogression, Oligometastatic Disease, OligoProgressive Metastatic Disease
Enrollment	194 participants
Start Date	2025-12-04
Primary Completion	2030-06-01 (estimated)
Study Completion	2033-06-01 (estimated)
Updated on ClinicalTrials.gov	2025-12-15