Study on Adding Precisely Targeted Radiation Therapy (Stereotactic Body Radiation Therapy) to the Usual Treatment Approach (Drug Therapy) in Patients with Metastatic Breast Cancer, The AIM-B Study

PRIMARY OBJECTIVE:

I. To assess if stereotactic body radiation therapy (SBRT) improves 3 month progression free survival, defined as time from first SBRT treatment to disease progression or death.

SECONDARY OBJECTIVES:

I. To assess time to next line systemic therapy.

II. To assess overall survival.

III. To assess local control of irradiated lesion using positron emission tomography (PET) Response Criteria in Solid Tumors (PERCIST).

IV. To assess time to failure/progression outside of irradiated lesion.

V. To assess toxicity of SBRT.

VI. To assess long term progression free survival at 6 and 12 months.

EXPLORATORY OBJECTIVES:

I. To assess rate of circulating tumor-deoxyribonucleic acid (ctDNA) clearance 3 months following SBRT using existing data from 12-245 that corresponds with the following timepoints: screening, within one week of last radiation treatment, 3 months , 6 months and 12 months after last radiation.

II. To assess changes in ctDNA mutational profile in response to SBRT using existing data from 12-245 that corresponds with the following timepoints: screening, within one week of last radiation treatment, 3 months, 6 months and 12 months after last radiation.

OUTLINE:

Patients undergo SBRT and receive standard of care drug therapy on study. Patients undergo magnetic resonance imaging (MRI) and collection of blood samples during screening. Patients also undergo positron emission tomography (PET) throughout the trial.

After completion of study treatment, patients are followed up for 1 year.