Description Module
The Description Module contains narrative descriptions of the clinical trial, including a brief summary and detailed description. These descriptions provide important information about the study's purpose, methodology, and key details in language accessible to both researchers and the general public.
Description Module path is as follows:
Study -> Protocol Section -> Description Module
Description Module
Ignite Creation Date:
2025-12-25 @ 2:45 AM
Ignite Modification Date:
2025-12-25 @ 2:45 AM
NCT ID:
NCT05955833
Brief Summary:
The goal of this clinical trial is to test a new PET tracer in patients with HER2-positive breast or gastric cancer. This tracer is made of radioactively labeled trastuzumab, and can show where HER2 is present in the body using a PET-scan. For this research, the investigators make PET-scans in people with HER2-positive, metastasized breast- or gastric cancer. The investigators will investigate if the new HER2-tracer correctly shows all tumor lesions. In the future, this method may be useful to help predict who will benefit from certain HER2-directed therapies.
Participants will be injected with the radioactive tracer once. After injection, participants will undergo 3 PET-scans. Each PET-scan will take a maximum of 60 minutes. The PET-scans are on separate days within a week after injection of the tracer (e.g. 1 day, 2 days and 4 days after injection). Furthermore, the investigators will take 7 blood samples (5 mL each). Participants are not required to stay at the hospital. The first 3 participants will undergo an extra PET-scan 1 - 2 hours after injection.
The amount of radioactivity injected will be 37 MBq (± 10%).
Detailed Description:
Positron emission tomography (PET) imaging with 89Zr-labeled trastuzumab can potentially discriminate between human epidermal growth factor 2 (HER2) positive and HER2-negative lesions in cancer patients. The obvious advantage over tumor biopsies is that PET imaging provides an overview regarding the heterogeneity of HER2-positivity of all lesions in the patient noninvasively at any given time. The use of a tracer with high specificity and low background signal is critical for accurately identifying positive lesions in patients. Earlier studies in patients with HER2-positive (HER2+) breast cancer and gastric cancer using 89Zr-trastuzumab led to the identification of HER2-positive tumor lesions. However, also lesions were missed and false-positive lesions were seen. Previous work has shown that organs like liver and spleen have significant uptake of 89Zr-trastuzumab. In addition, HER2-directed therapy is most effective in HER2-positive tumors, which are defined as immunohistochemistry (IHC) HER2 expression 3+ or HER2 2+ with gene amplification. Tumors with IHC 0, 1+ or 2+ without amplification are considered HER2-negative. To be able to discriminate between these expression levels with PET imaging, an excellent signal to background ratio is required. Recently, an improved 89Zr-labeled trastuzumab tracer has been developed using a different chelator for 89Zr binding, DFO\*, which further improves stability of the 89Zr-labeled trastuzumab tracer. 89Zr-DFO\*-trastuzumab preclinically shows improved specificity in uptake of tumor lesions while non-tumor related uptake in bone, liver and spleen is reduced, potentially improving the discrimination of HER2-positive tumor lesions in patients. The investigators hypothesize that the improved 89Zr-DFO\*-trastuzumab tracer will lead to a reduced background uptake and thus a better discrimination of HER2-positive tumor lesions.
Study:
NCT05955833
Study Brief:
Protocol Section:
NCT05955833