Overview
The GATHER trial aim to evaluate the diagnostic performance of \[68Ga\]Ga-NOTA-anti-HER2-sdAb PET/CT in predicting pCR following neoadjuvant chemotherapy. This study is part of the development of new functional, non-invasive approaches with the aim of offering personalized therapeutic approaches.
Description
In early-stage HER2-positive breast cancer, neoadjuvant chemotherapy is frequently required, and pathological complete response (pCR) correlates with excellent prognosis. However, no non-invasive imaging method reliably predicts pCR, making surgery mandatory despite its aesthetic, functional, and psychological burden. Recently, new functional imaging tracers targeting the HER2 protein have been developed. Among these, \[68Ga\]Ga-NOTA-anti-HER2-sdAb is of particular interest due to its molecular characteristic; it has demonstrated favorable safety profile and ability to identify HER2+ cells in vivo. This trial evaluates its ability to predict pCR, with the prospect of paving the way for future therapeutic de escalation and surgical sparing.
Eligibility
Inclusion Criteria:
- Female aged 18 years or older
- Histologically proven HER2-positive early breast cancer, defined as IHC 3+ or IHC 2+ with ISH amplification
- Indication for neoadjuvant chemotherapy combined with anti-HER2 targeted therapy followed by surgery, as determined by a multidisciplinary tumor board
- ECOG performance status of 0 or 1
- Affiliated to or beneficiary of a social protection scheme
- Written informed consent signed prior to any study-specific procedure
Exclusion Criteria:
- Pregnant or breastfeeding women
- Patient not treated with curative intent
- History of ipsilateral breast cancer treated by surgery and/or radiotherapy
- Lobular histology
- Known contraindication or hypersensitivity to \[68Ga\]Ga-NOTA-anti-HER2-sdAb or any of its radiopharmaceutical excipients
- Known contraindication or hypersensitivity to \[18F\]F-FDG or any of its radiopharmaceutical excipients
- Concurrent enrollment in another clinical trial evaluating radiopharmaceuticals
- Patient under guardianship, curatorship, or judicial protection
- Patient deprived of liberty
- Inability to understand the study or comply with trial constraints due to linguistic, psychological, or geographical barriers


