About this trial
This study plans to enroll 30 patients with locally advanced or metastatic triple-negative breast cancer (TNBC) who are scheduled to receive at least two cycles of a regimen containing an immune checkpoint inhibitor (ICI). All ICI treatments must be administered in accordance with current clinical indications. For patients who intend to participate in a clinical trial involving an ICI, they must meet the eligibility criteria of that specific trial protocol.
After screening and enrollment, participants will undergo a \[68Ga\]Ga-DOTA-GSI PET/CT (Granzyme B PET/CT) scan before initiating the ICI-containing regimen and again after Cycle 2 (C2). Participants will continue the ICI regimen until disease progression, with tissue biopsies performed as needed.
By integrating patients' baseline clinical characteristics, treatment outcomes, and prognostic information, this study aims to conduct a comprehensive analysis. The objective is to investigate whether the following factors, as assessed by Granzyme B PET/CT, can serve as early predictors of response to immunotherapy in patients with advanced breast cancer: baseline Granzyme B expression levels, immunotherapy-activated Granzyme B levels after C2, and the heterogeneity of Granzyme B expression at baseline and after C2.
Eligibility criteria
Qualifiers
Age ≥ 18 years.
Histologically confirmed unresectable locally advanced or metastatic breast cancer, with immunohistochemistry (IHC) results indicating negativity for ER, PR, and Her-2. If pathology from a metastatic lesion is available, its histology will take precedence.
Decision by the clinician to treat with a regimen containing an immune checkpoint inhibitor (ICI), with the patient scheduled to receive at least 2 cycles of treatment.
Disqualifiers
Eastern Cooperative Oncology Group (ECOG) performance status of 0 or 1.
Evidence of radiological or objective disease progression during or after the most recent systemic therapy prior to study entry, or intolerance to the toxicity of prior treatment.
Life expectancy of ≥ 12 weeks at the time of screening.
Presence of at least one measurable lesion that has not been previously irradiated. The lesion must have a longest diameter of ≥10 mm at baseline as measured by CT or MRI (for lymph nodes, the short axis must be ≥15 mm). In cases where only bone lesions are present, lytic or mixed lytic-blastic bone lesions that can be assessed by CT, MRI, or X-ray are acceptable.
Trial design
Treatments tested in this trial
- [68Ga]Ga-DOTA-GSI PET/CT (Granzyme B PET/CT)