[68Ga]DOTA-TOC for tumor imaging

Ga-68-DOTA-TOC is being developed through an IND for use in healthy subjects and will eventually be employed in the clinical management of a range of oncologic and non-oncologic diseases in various capacities, including diagnosis, treatment planning, surveillance, and assessment of response to therapy.

Ga-68-DOTA-TOC (or edotreotide Ga-68 Injection) is a radiolabeled, receptor-targeted, tumor imaging agent for PET. It uses a peptide mimetic, somatostatin, of the natural inhibitory hormone to target somatostatin receptors to image tumors. Somatostatin receptors (SSTRs) are frequently overexpressed on human tumor cells. The short half-life of Ga-68 (67.7 min), high SSTR selectivity of TOC and rapid background clearance, make Ga-68-DOTA-TOC an ideal radiotracer for receptor PET imaging.

The I3 is supporting the development of Ga-68-DOTA-TOC for human studies under the investigational new drug (IND) mechanism.

Ga-68-DOTA-TOC has the advantage over other imaging agents such as the In-111-pentetreotide, with the concordant higher resolution and sensitivity of positron emission tomography (PET) in comparison with single photon emission computed tomography (SPECT). Additionally, background activity is reduced, further improving image quality. In addition the shorter half-life of Ga-68 allows repeat administrations and a reduced radiation exposure to the patient. The short-lived Ga-68 can be obtained from its long-lived parent Ge-68 from a commercial isotope generator that avoids the cost and maintenance of on a site cyclotron. The relatively simple and rapid labeling of DOTA-TOC can be performed on an everyday basis, allowing its use to broadly help clinical and research efforts at MGH.