[68Ga]Ga-NeoB

Overview

[⁶⁸Ga]Ga-NeoB (formerly ⁶⁸Ga-NeoBOMB1) is an investigational radioactive tracer for positron-emission tomography (PET), not a cancer treatment. Human imaging studies have reported results in breast cancer, prostate cancer, and gastrointestinal stromal tumors (GIST). Its potential role in diagnosis and patient selection remains under evaluation. (pubmed.ncbi.nlm.nih.gov)

Mechanism of action

NeoB is an antagonist that binds the gastrin-releasing peptide receptor (GRPR), which is expressed by some tumors. Gallium-68 emits positrons, allowing areas of tracer uptake to be seen on PET scans. The same NeoB targeting molecule can be labeled with lutetium-177 for investigational radionuclide therapy; results for that treatment should not be attributed to the gallium-68 imaging tracer. (jnm.snmjournals.org)

Imaging results

• Breast cancer: In a prospective study of 20 patients with ER/PR-positive, HER2-negative disease, NeoB PET/CT was positive in 15/20 (75%), versus 13/20 (65%) for FDG PET/CT. These are positive-scan rates, not treatment response rates or established measures of diagnostic accuracy. (pubmed.ncbi.nlm.nih.gov)
• GIST: In a nine-patient phase I/IIa study, 6/9 patients had uptake in at least one tumor lesion; 17/37 assessed lesions showed significant uptake. The variable uptake limits what this small study can establish about diagnostic performance. (pmc.ncbi.nlm.nih.gov)

Safety

In the initial six GIST participants, no serious adverse events or events judged causally related to the tracer were reported over four weeks. The pancreas received the highest estimated organ radiation dose. These small studies cannot establish safety for broader use. (jnm.snmjournals.org)

Further reading

• Prospective breast-cancer imaging study (pubmed.ncbi.nlm.nih.gov)
• Phase I/IIa GIST imaging results (pmc.ncbi.nlm.nih.gov)
• Initial GIST safety and dosimetry study (pubmed.ncbi.nlm.nih.gov)

Last updated: Sep 2026