Evaluation of the diagnostic potential of HER2 imaging using zirconium 89 labelled trastuzumab.

This is the first belgian feasibility study of HER2 imaging using a labelled monoclonal antibody, namely trastuzumab labelled with zirconium 89.

The aims of this study are:

I/ Evaluate the diagnostic potential of HER2 imaging using zirconium 89 labelled trastuzumab (based on the Groningen experience), through the analysis of the correlation between the FDG-PET/CT and the HER2 immunoPET.

II/ PET quantification of HER2 receptor by using the images and the blood pharmacokinetic of the tracer.

III/ In the subset of patients for whom biopsies of metastatic sites have not been carried out previously and are of an easy access, tissue will be acquired as part of the validation of the HER2 immunoPET and as an attempt to better understand the molecular heterogeneity of HER2 positive breast cancer at the time of relapse.

IV/Evaluate the concentration of circulating HER2 extracellular domain in the blood and study his possible role as on imaging quality

Inclusion criteria:

1. All patients selected for this imaging study are patients scheduled to start trastuzumab-based therapy for advanced HER2 positive breast cancer (This includes trastuzumab alone, trastuzumab + chemotherapy, trastuzumab + endocrine therapy).
2. Histologically confirmed HER 2 positive (defined as FISH amplification ratio more than 2.2) invasive carcinoma of the breast (primary tumor at diagnosis) with locally recurrent or metastatic disease.
3. Patients with FDG-PET positive metastatic lesions.
4. Brain metastases are allowed provided they are controlled and they are not the sole site of metastatic disease.
5. Patient planned to have metastatic site biopsy for HER2 status control.
6. Age ≥ 18 years
7. Eastern Cooperative Oncology Group (ECOG) performance status (PS) 0 to 1
8. For women of childbearing potential a pregnancy test will be done and an agreement to use a highly-effective non hormonal form of contraception.
9. Agreement from the patient to participate in this imaging study and if indicated agreement to biopsy one or two accessible lesions.
10. Signed written informed consent (approved by the Ethics Committee) obtained prior to any study procedure

Exclusion criteria:

1. Current severe, uncontrolled systemic disease (e.g., clinically significant cardiovascular, pulmonary, or metabolic disease)
2. Pregnant or lactating women
3. Current known infection with HIV, HBV, or HCV
4. Known severe hypersensitivity to trastuzumab
5. Assessed by the investigator to be unable or unwilling to comply with the requirements of the protocol
6. Patients with bone only metastases are not eligible
7. Psychiatric illness/social situations that would limit compliance with study requirements
8. Patients who received lapatinib within the 7 days prior to HER immunoPET/CT.