Stereotactic Radiotherapy Versus Palliative Conventional Radiotherapy for Oligoprogressive Metastatic Cancers

NCT06918951 | Recruiting DMC

• 1 other identifier: STOP-2
• Study Type: interventional
• Target: 194
• Locations: 1 country
• Sites: 1

Brief Summary

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.

Conditions

Oligoprogression; Oligometastatic Disease; OligoProgressive Metastatic Disease

Keywords

SABR; Radiotherapy; Quality of life; Metastatic Cancer

Outcome Measures

Primary Outcomes (3)

• Progression-Free Survival on Next Line Systemic Therapy (PFS-NEST)

  Time from randomization to progression (RECIST criteria) beyond next line of systemic therapy or death from any cause or date of last follow-up, whichever occurs first. Next line systemic therapy is the first new systemic therapy initiated after documented disease progression

  3 months, 6 months, 12 months, 15 months, 18 months, 21 months, 24 months, 36 months, 42 months, 48 months, 54 months, 60 months

• Evaluation of feasibility of the clinical trial in terms of successful accrual

  Accrual will be measured by the number of participants enrolled in the trial within the specified time frame.

  12 and 24 months

• Evaluation of feasibility of the clinical trial in terms of success of double-blinding

  The success of double-blinding will be measured by providing both the participant and oncologist with a blinding questionnaire asking them to select the suspected trial arm assignment (options include palliative arm, SABR arm, or unknown).

  6 weeks

Secondary Outcomes (10)

• Evaluation of OS, PFS, and PPFS

  3 months, 6 months, 12 months, 15 months, 18 months, 21 months, 24 months, 36 months, 42 months, 48 months, 54 months, 60 months

• Time to next line systemic therapy

  3 months, 6 months, 12 months, 15 months, 18 months, 21 months, 24 months, 36 months, 42 months, 48 months, 54 months, 60 months

• Comparing the anatomic sites of disease progression

  3 months, 6 months, 12 months, 15 months, 18 months, 21 months, 24 months, 36 months, 42 months, 48 months, 54 months, 60 months

• Evaluation of the treatment related toxicities

  3 months, 6 months, 12 months, 15 months, 18 months, 21 months, 24 months, 36 months, 42 months, 48 months, 54 months, 60 months

• Comparing the quality of life among participants in each arm using Functional Assessment of Cancer Therapy: General (FACT-G)

  3 months, 6 months, 12 months, 15 months, 18 months, 21 months, 24 months, 36 months, 42 months, 48 months, 54 months, 60 months

Study Arms (2)

Control Arm (Palliative Radiotherapy)

ACTIVE COMPARATOR

Radiation: Palliative radiotherapy

Experimental Arm (SABR)

EXPERIMENTAL

Radiation: Stereotactic ablative radiotherapy (SABR)

Interventions

Stereotactic ablative radiotherapy (SABR) RADIATION

SABR is a safe and effective modality for metastasis-directed therapy, delivering a high dose of radiotherapy to a small target using conformal techniques. Emerging evidence suggests that SABR for oligoprogressive cancer may extend the duration of systemic therapy, and result in improvements in Progression Free Survival (PFS) and Overall Survival (OS) compared to historic controls.

Experimental Arm (SABR)

Palliative radiotherapy RADIATION

Radiotherapy will consist of 8 Gy in 1 fraction to all sites of oligoprogression. Participants will continue their current systemic therapy (if already on systemic therapy at the time of oligoprogression event) or continue off systemic therapy (if the participant was not on systemic therapy at the time of the oligorecurrence event).

Control Arm (Palliative Radiotherapy)

Eligibility Criteria

• Age: 19 Years+
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• Age 19 or older
• Able to provide informed consent
• Histologically confirmed solid malignancy (excluding lymphoma or myeloma) with metastatic disease detected on imaging
• Biopsy of metastasis at some time prior to enrollment is preferred, but not required
• ECOG performance status 0-2
• Life expectancy ≥ 6 months
• Progression meeting RECIST criteria in up to 5 individual lesions. Progression may be defined as:
• Progression of an individual metastasis according to RECIST 1.1 criteria (≥ 20% enlargement of the tumour vs. baseline or nadir, taking as reference the smallest diameter seen prior to starting or during systemic therapy, and associated with a 5 mm minimum increase in size) OR
• Unambiguous development of a new metastatic lesion at least 5 mm in size OR
• Progressive enlargement of a known metastasis on 2 consecutive imaging studies 2-3 months apart with a minimum 5 mm increase in size from baseline.
• A progressing primary tumor is eligible as per the criteria above
• If the participant is on systemic therapy at the time of oligoprogression:
• The most recent systemic therapy agent must have been delivered for a total of at least 3 months, with an initial partial response (PR), complete response (CR) or stable disease (SD) prior to the development of oligoprogressive lesions
• If the participant is not on systemic therapy at the time of oligoprogression:
• (i.e., "oligorecurrence"(1), however, included as "oligoprogression" for the purpose of this study protocol):

You may not qualify if:

• Serious medical comorbidities precluding radiotherapy. These include ataxia-telangiectasia or scleroderma, Crohn's disease in participants where the gastrointestinal (GI) tract will receive radiotherapy, or ulcerative colitis where the bowel will receive radiotherapy.
• a. For participants with oligoprogressive lesions in the lung or thorax, this includes interstitial lung disease.
• Substantial overlap with a previously treated radiation volume. Prior radiotherapy in general is allowed, provided that the composite plan meets dose constraints herein. For participants treated with radiation previously, biological effective dose calculations should be used to equate previous doses to the tolerance doses listed in Appendix 1. A tissue recovery factor may be used in these calculations and if so, must be clearly documented, along with elapsed time from previous radiotherapy, and approved by the local principal investigator.
• Current malignant pleural effusion, malignant ascites, or leptomeningeal disease
• Inability to treat all sites of oligoprogressive disease
• Liver metastases requiring placement of fiducial markers for SABR, as this would compromise successful blinding. Liver metastases are eligible if: 1) they are treated at an institution that offers liver SABR without fiducial markers or 2) pre-existing markers such as surgical clips or calcifications would serve as fiducial markers
• Brain metastasis \> 3.5 cm in size or a total volume of brain metastases greater than 30 cc.
• Clinical or radiologic evidence of spinal cord compression. Participants can be eligible if surgical resection has been performed.
• Participants with spine instability as judged by a Spinal Instability Neoplastic Score (SINS) of \>12.
• Dominant brain metastasis requiring surgical decompression
• For participants with liver metastases; moderate/severe liver dysfunction (Child Pugh B or C)
• Liver metastases located in the "Biliary no fly zone" defined for this trial as common biliary track, cystic duct and distal branches (1 cm) + 5 mm
• Surgical resection of all oligoprogression metastases (i.e. no lesion available to be treated with SABR)
• Pregnant or lactating individuals

Sponsors & Collaborators

• British Columbia Cancer Agency: lead

Study Sites (1)

BC Cancer - Surrey

Surrey, British Columbia, V3V 1Z2, Canada

RECRUITING

MeSH Terms

Conditions

Neoplasm Metastasis

Condition Hierarchy (Ancestors)

Neoplastic Processes; Neoplasms; Pathologic Processes; Pathological Conditions, Signs and Symptoms

Central Study Contacts

Sarah Baker, MD, PhD, FRCPC

CONTACT

604-930-4032; sarah.baker1@bccancer.bc.ca

Narsis Afghari, MSc.

CONTACT

604-675-4100; narsis.afghari@bccancer.bc.ca

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: TRIPLE
• Who Masked: PARTICIPANT, INVESTIGATOR, OUTCOMES ASSESSOR
• Masking Details: This is a double-blind trial. Participants, enrolling oncologists, and the statistician will be blinded to trial arm assignment. The Coordinating Centre will not be blinded and will maintain a list of trial arm assignments (unblinding master list, in electronic format and accessible to project managers at the Coordinating Centre). Randomization will occur at the Coordinating Centre, and randomization results will be communicated to the clinical trials unit of the participating centre. The trial arm assignment will not be documented at the participating centre. The trials unit staff at the participating centre will then notify the non-enrolling oncologist of the trial arm assignment.
• Purpose: TREATMENT
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: SPONSOR

Model Details: This study is a phase III, multicenter, double-blind, randomized trial. Participants will be randomized in a 1:1 ratio between conventional palliative radiotherapy (Control Arm; Arm 1) vs. SABR (Experimental Arm; Arm 2) to all sites of oligoprogressing disease.

Study Record Dates

• First Submitted: March 10, 2025
• First Posted: April 9, 2025
• Study Start: December 4, 2025
• Primary Completion (Estimated): June 1, 2030
• Study Completion (Estimated): June 1, 2033
• Last Updated: December 15, 2025

Record last verified: 2025-12

Locations

CA (1)