Human epidermal growth factor receptor 2 (HER2) biomarkers have been the standard for imaging agents that target hormonally active breast cancers that tend to be very aggressive. Now researchers have developed an alternative and potentially more comprehensive biomarker of disease, HER3, according to a study presented during this week’s Society of Nuclear Medicine and Molecular Imaging’s 2014 Annual Meeting, which was held June 7-11 in St. Louis.

HER2-positive receptor expression is a telltale sign of advanced cancer. An investigative antibody-based agent called Cu-64 DOTA-HER3 F(ab')2 hits on HER3, a signaler for a HER2-positive tumors across a number of preclinical models using PET. HER3 may hint toward more resistant and aggressive forms of breast cancer, which could translate into a more ideal target for not just imaging, but future treatments.

“If clinically translated, imaging agents such as our HER3 PET Probe represent a maturation of molecular imaging to be able to prospectively guide therapeutic choices for cancer, rather than reporting retrospectively on success or failure of a given therapy,” said principal author Eric P. Wehrenberg-Klee, MD, from Massachusetts General Hospital in Boston. “We hope for clinical translation of this probe over the next 1-2 years.”