Anti-HER2 monoclonal antibody based-radioimmunoconjugates: Assessment of the chelating agent influence

Ana Cláudia Camargo Miranda1, Ana Claudia Ranucci Durante2, Leonardo Lima Fuscaldi2

  • 1Hospital Israelita Albert Einstein, Avenida Albert Einstein, 627/701, Sao Paulo 05652-900, Brazil; Instituto de Pesquisas Energéticas e Nucleares/Comissão Nacional de Energia Nuclear (IPEN-CNEN), Avenida Professor Lineu Prestes, 2242, Sao Paulo 05508-000, Brazil.

In the present work, the radioimmunoconjugates 111In-DTPA-trastuzumab and 177Lu-DOTA-trastuzumab were evaluated regarding the influence of the chelating agents on the physical-chemical parameters and human epidermal growth factor receptor 2 (HER2) tumor cell binding. Data showed that both chelating agents, at predetermined molar ratios (antibody:chelator - 1:10 and 1:20), did not influence the immunoconjugates integrity, the radiolabeling process and the radiolabeled antibodies stability. However, differences were observed in the lipophilic feature between DOTA and DTPA radioimmunoconjugates and in the specific binding to SK-BR-3 tumor cells (HER2 positive). Therefore, this study showed the importance of assessing the influence of chelating agents and their molar ratios in the development process of radioimmunoconjugates.