Phase II Study of [68Ga]Ga-ABY-025 PET for Non-invasive Quantification of HER2-status in Solid Tumors
The goal of this phase II clinical trial is to improve the selection of patients with solid tumors who would benefit from effective treatment with HER2 targeted drugs. This will be achieved by examining patients with HER2 positive tumors in the esophagus or stomach or patients with advanced breast cancer with low HER2 expression (HER2low) with the HER2 specific positron emission tomography (PET) tracer ABY-025 (HER2-PET) and compare the imaging results with HER2 expression in tumor tissue derived from biopsies (reference standard).
• Age ≥18 years.
• The subject has given written consent to participate in the study.
• Patients with metastatic disease because of gastroesophageal adenocarcinoma or HER2-low breast cancer. Cohort 1: Histologically confirmed HER2-positive primary gastroesophageal adenocarcinoma, scheduled for palliative HER2-targeted therapy; Cohort 2: HER2-low metastatic breast cancer first within a pilot study (of which five patients with de novo HER2-low mBC and five patients with pre-treated HER2-low mBC). Later, within a post-pilot study. Definition of HER2 positivity (ASCO College of American Pathologist 2018. HER2 Testing for Breast Cancer Guidelines.) HER2-low mBC is defined as IHC 1+ or IHC 2+ but ISH negative.
• At least one metastatic lesion ≥ 10 mm is available for biopsy defined on CT.
• At least one (and up to five) additional metastatic index lesion/s ≥ 10 mm for evaluation of treatment effect
• World Health Organization (WHO) performance status ≤ 2.
• Expected survival \> 12 weeks.