Kit for the preparation of In-labeled pertuzumab injection for imaging response of HER2-positive breast cancer to trastuzumab (Herceptin).

We previously reported that In-labeled pertuzumab imaged trastuzumab (Herceptin)-mediated changes in HER2 expression preclinically in breast cancer tumors. To advance In-labeled pertuzumab to a Phase I/II clinical trial, a kit was designed for preparing this agent in a form suitable for human administration. Unit-dose kits containing pertuzumab modified with 2-(4-isothiocyanatobenzyl)-diethylenetriaminepentaacetic acid (BzDTPA) were prepared that labeled to high efficiency (>90%) with In and met specifications for pharmaceutical quality. The kits were stable for 4 months and the final radiopharmaceutical was stable for 24h. Imaging studies demonstrated high and specific uptake in HER2-positive tumors in mice using this clinical kit formulation.