Pilot study of 68Ga-DOTA-F(ab′)2-trastuzumab in patients with breast cancer

Objective(68)Ga-1,4,7,10-Tetraazacyclododecane-N,N,N,N-tetraacetic acid (DOTA)-F(ab)(2)-trastuzumab [Ga-68-DOTA-F(ab)(2)-trastuzumab] has been developed at our institution as a positron imaging reagent for assessing human epidermal growth factor receptor 2 (HER2) expression status by in-vivo imaging. Initial studies on animals demonstrated promising results in the monitoring of treatment response to heat shock protein 90-targeted drugs that inhibit the client protein HER2. We report here our initial clinical experience in the assessment of the toxicity, pharmacokinetics, biodistribution, and dosimetry profile of Ga-68-DOTA-F(ab)(2)-trastuzumab with PET/computed tomography using a mean of 236 MBq/5 mg administered intravenously.Materials and methodsA group of 16 women with breast cancer were enrolled in this study. The one patient who did not receive Ga-68-DOTA-F(ab)(2)-trastuzumab was excluded from analysis. Both HER2-negative (n=7) and HER2-positive (n=8) cases were studied. Among the latter, seven had undergone trastuzumab treatment previously and one had not.ResultsIt was determined that Ga-68-DOTA-F(ab)(2)-trastuzumab was well tolerated, with a T-1/2 of approximate to 3.60.9 h; the critical organ was the kidney, with a mean dose of 0.383 cGy/37 MBq; and tumor targeting was seen in 4/8 patients with HER2-positive disease.ConclusionThe reagent is safe, and assessments through additional studies in a better-defined group of patients, using larger administered masses of antibodies, with a better immunoreactive fraction are needed. (C) 2013 Wolters Kluwer Health vertical bar Lippincott Williams & Wilkins.